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Merge branch 'master' of /repos/git/linux-2.6

Browse Source 
Conflicts:
	net/ipv4/netfilter/nf_nat_core.c
	net/netfilter/nf_conntrack_core.c
	net/netfilter/nf_conntrack_netlink.c

Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Patrick McHardy
2010-03-08 12:55:23 +01:00
parent 9ab48ddcb1 25cf84cf37
commit f790c0ca6f
9440 changed files with 640878 additions and 263751 deletions
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9
.gitignore vendored
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@@ -22,6 +22,7 @@
*.lst
*.symtypes
*.order
modules.builtin
*.elf
*.bin
*.gz
@@ -35,7 +36,9 @@
#
tags
TAGS
linux
vmlinux
vmlinuz
System.map
Module.markers
Module.symvers
@@ -45,14 +48,8 @@ Module.symvers
#
# Generated include files
#
include/asm
include/asm-*/asm-offsets.h
include/config
include/linux/autoconf.h
include/linux/compile.h
include/linux/version.h
include/linux/utsrelease.h
include/linux/bounds.h
include/generated
# stgit generated dirs

7
Documentation/ABI/stable/sysfs-devices-node Normal file
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@@ -0,0 +1,7 @@
What: /sys/devices/system/node/nodeX
Date: October 2002
Contact: Linux Memory Management list <linux-mm@kvack.org>
Description:
When CONFIG_NUMA is enabled, this is a directory containing
information on node X such as what CPUs are local to the
node.

12
Documentation/ABI/testing/ima_policy
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@@ -20,7 +20,7 @@ Description:
lsm: [[subj_user=] [subj_role=] [subj_type=]
[obj_user=] [obj_role=] [obj_type=]]
base: func:= [BPRM_CHECK][FILE_MMAP][INODE_PERMISSION]
base: func:= [BPRM_CHECK][FILE_MMAP][FILE_CHECK]
mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC]
fsmagic:= hex value
uid:= decimal value
@@ -40,11 +40,11 @@ Description:
measure func=BPRM_CHECK
measure func=FILE_MMAP mask=MAY_EXEC
measure func=INODE_PERM mask=MAY_READ uid=0
measure func=FILE_CHECK mask=MAY_READ uid=0
The default policy measures all executables in bprm_check,
all files mmapped executable in file_mmap, and all files
open for read by root in inode_permission.
open for read by root in do_filp_open.
Examples of LSM specific definitions:
@@ -54,8 +54,8 @@ Description:
dont_measure obj_type=var_log_t
dont_measure obj_type=auditd_log_t
measure subj_user=system_u func=INODE_PERM mask=MAY_READ
measure subj_role=system_r func=INODE_PERM mask=MAY_READ
measure subj_user=system_u func=FILE_CHECK mask=MAY_READ
measure subj_role=system_r func=FILE_CHECK mask=MAY_READ
Smack:
measure subj_user=_ func=INODE_PERM mask=MAY_READ
measure subj_user=_ func=FILE_CHECK mask=MAY_READ

14
Documentation/ABI/testing/sysfs-block
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@@ -128,3 +128,17 @@ Description:
preferred request size for workloads where sustained
throughput is desired. If no optimal I/O size is
reported this file contains 0.
What: /sys/block/<disk>/queue/nomerges
Date: January 2010
Contact:
Description:
Standard I/O elevator operations include attempts to
merge contiguous I/Os. For known random I/O loads these
attempts will always fail and result in extra cycles
being spent in the kernel. This allows one to turn off
this behavior on one of two ways: When set to 1, complex
merge checks are disabled, but the simple one-shot merges
with the previous I/O request are enabled. When set to 2,
all merge tries are disabled. The default value is 0 -
which enables all types of merge tries.

29
Documentation/ABI/testing/sysfs-bus-usb
View File

@@ -21,25 +21,27 @@ Contact: Alan Stern <stern@rowland.harvard.edu>
Description:
Each USB device directory will contain a file named
power/level. This file holds a power-level setting for
the device, one of "on", "auto", or "suspend".
the device, either "on" or "auto".
"on" means that the device is not allowed to autosuspend,
although normal suspends for system sleep will still
be honored. "auto" means the device will autosuspend
and autoresume in the usual manner, according to the
capabilities of its driver. "suspend" means the device
is forced into a suspended state and it will not autoresume
in response to I/O requests. However remote-wakeup requests
from the device may still be enabled (the remote-wakeup
setting is controlled separately by the power/wakeup
attribute).
capabilities of its driver.
During normal use, devices should be left in the "auto"
level. The other levels are meant for administrative uses.
level. The "on" level is meant for administrative uses.
If you want to suspend a device immediately but leave it
free to wake up in response to I/O requests, you should
write "0" to power/autosuspend.
Device not capable of proper suspend and resume should be
left in the "on" level. Although the USB spec requires
devices to support suspend/resume, many of them do not.
In fact so many don't that by default, the USB core
initializes all non-hub devices in the "on" level. Some
drivers may change this setting when they are bound.
What: /sys/bus/usb/devices/.../power/persist
Date: May 2007
KernelVersion: 2.6.23
@@ -157,3 +159,14 @@ Description:
device. This is useful to ensure auto probing won't
match the driver to the device. For example:
# echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
What: /sys/bus/usb/device/.../avoid_reset
Date: December 2009
Contact: Oliver Neukum <oliver@neukum.org>
Description:
Writing 1 to this file tells the kernel that this
device will morph into another mode when it is reset.
Drivers will not use reset for error handling for
such devices.
Users:
usb_modeswitch

14
Documentation/ABI/testing/sysfs-devices-memory
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@@ -60,6 +60,19 @@ Description:
Users: hotplug memory remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/
What: /sys/devices/system/memoryX/nodeY
Date: October 2009
Contact: Linux Memory Management list <linux-mm@kvack.org>
Description:
When CONFIG_NUMA is enabled, a symbolic link that
points to the corresponding NUMA node directory.
For example, the following symbolic link is created for
memory section 9 on node0:
/sys/devices/system/memory/memory9/node0 -> ../../node/node0
What: /sys/devices/system/node/nodeX/memoryY
Date: September 2008
Contact: Gary Hade <garyhade@us.ibm.com>
@@ -70,4 +83,3 @@ Description:
memory section directory. For example, the following symbolic
link is created for memory section 9 on node0.
/sys/devices/system/node/node0/memory9 -> ../../memory/memory9

79
Documentation/ABI/testing/sysfs-devices-power Normal file
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@@ -0,0 +1,79 @@
What: /sys/devices/.../power/
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../power directory contains attributes
allowing the user space to check and modify some power
management related properties of given device.
What: /sys/devices/.../power/wakeup
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../power/wakeup attribute allows the user
space to check if the device is enabled to wake up the system
from sleep states, such as the memory sleep state (suspend to
RAM) and hibernation (suspend to disk), and to enable or disable
it to do that as desired.
Some devices support "wakeup" events, which are hardware signals
used to activate the system from a sleep state. Such devices
have one of the following two values for the sysfs power/wakeup
file:
+ "enabled\n" to issue the events;
+ "disabled\n" not to do so;
In that cases the user space can change the setting represented
by the contents of this file by writing either "enabled", or
"disabled" to it.
For the devices that are not capable of generating system wakeup
events this file contains "\n". In that cases the user space
cannot modify the contents of this file and the device cannot be
enabled to wake up the system.
What: /sys/devices/.../power/control
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../power/control attribute allows the user
space to control the run-time power management of the device.
All devices have one of the following two values for the
power/control file:
+ "auto\n" to allow the device to be power managed at run time;
+ "on\n" to prevent the device from being power managed;
The default for all devices is "auto", which means that they may
be subject to automatic power management, depending on their
drivers. Changing this attribute to "on" prevents the driver
from power managing the device at run time. Doing that while
the device is suspended causes it to be woken up.
What: /sys/devices/.../power/async
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../async attribute allows the user space to
enable or diasble the device's suspend and resume callbacks to
be executed asynchronously (ie. in separate threads, in parallel
with the main suspend/resume thread) during system-wide power
transitions (eg. suspend to RAM, hibernation).
All devices have one of the following two values for the
power/async file:
+ "enabled\n" to permit the asynchronous suspend/resume;
+ "disabled\n" to forbid it;
The value of this attribute may be changed by writing either
"enabled", or "disabled" to it.
It generally is unsafe to permit the asynchronous suspend/resume
of a device unless it is certain that all of the PM dependencies
of the device are known to the PM core. However, for some
devices this attribute is set to "enabled" by bus type code or
device drivers and in that cases it should be safe to leave the
default value.

29
Documentation/ABI/testing/sysfs-devices-system-cpu
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@@ -62,6 +62,35 @@ Description: CPU topology files that describe kernel limits related to
See Documentation/cputopology.txt for more information.
What: /sys/devices/system/cpu/probe
/sys/devices/system/cpu/release
Date: November 2009
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: Dynamic addition and removal of CPU's. This is not hotplug
removal, this is meant complete removal/addition of the CPU
from the system.
probe: writes to this file will dynamically add a CPU to the
system. Information written to the file to add CPU's is
architecture specific.
release: writes to this file dynamically remove a CPU from
the system. Information writtento the file to remove CPU's
is architecture specific.
What: /sys/devices/system/cpu/cpu#/node
Date: October 2009
Contact: Linux memory management mailing list <linux-mm@kvack.org>
Description: Discover NUMA node a CPU belongs to
When CONFIG_NUMA is enabled, a symbolic link that points
to the corresponding NUMA node directory.
For example, the following symlink is created for cpu42
in NUMA node 2:
/sys/devices/system/cpu/cpu42/node2 -> ../../node/node2
What: /sys/devices/system/cpu/cpu#/node
Date: October 2009

109
Documentation/ABI/testing/sysfs-kernel-slab
View File

@@ -45,8 +45,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The alloc_fastpath file is read-only and specifies how many
objects have been allocated using the fast path.
The alloc_fastpath file shows how many objects have been
allocated using the fast path. It can be written to clear the
current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/alloc_from_partial
@@ -55,9 +56,10 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The alloc_from_partial file is read-only and specifies how
many times a cpu slab has been full and it has been refilled
by using a slab from the list of partially used slabs.
The alloc_from_partial file shows how many times a cpu slab has
been full and it has been refilled by using a slab from the list
of partially used slabs. It can be written to clear the current
count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/alloc_refill
@@ -66,9 +68,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The alloc_refill file is read-only and specifies how many
times the per-cpu freelist was empty but there were objects
available as the result of remote cpu frees.
The alloc_refill file shows how many times the per-cpu freelist
was empty but there were objects available as the result of
remote cpu frees. It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/alloc_slab
@@ -77,8 +79,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The alloc_slab file is read-only and specifies how many times
a new slab had to be allocated from the page allocator.
The alloc_slab file is shows how many times a new slab had to
be allocated from the page allocator. It can be written to
clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/alloc_slowpath
@@ -87,9 +90,10 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The alloc_slowpath file is read-only and specifies how many
objects have been allocated using the slow path because of a
refill or allocation from a partial or new slab.
The alloc_slowpath file shows how many objects have been
allocated using the slow path because of a refill or
allocation from a partial or new slab. It can be written to
clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/cache_dma
@@ -117,10 +121,11 @@ KernelVersion: 2.6.31
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file cpuslab_flush is read-only and specifies how many
times a cache's cpu slabs have been flushed as the result of
destroying or shrinking a cache, a cpu going offline, or as
the result of forcing an allocation from a certain node.
The file cpuslab_flush shows how many times a cache's cpu slabs
have been flushed as the result of destroying or shrinking a
cache, a cpu going offline, or as the result of forcing an
allocation from a certain node. It can be written to clear the
current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/ctor
@@ -139,8 +144,8 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file deactivate_empty is read-only and specifies how many
times an empty cpu slab was deactivated.
The deactivate_empty file shows how many times an empty cpu slab
was deactivated. It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/deactivate_full
@@ -149,8 +154,8 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file deactivate_full is read-only and specifies how many
times a full cpu slab was deactivated.
The deactivate_full file shows how many times a full cpu slab
was deactivated. It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/deactivate_remote_frees
@@ -159,9 +164,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file deactivate_remote_frees is read-only and specifies how
many times a cpu slab has been deactivated and contained free
objects that were freed remotely.
The deactivate_remote_frees file shows how many times a cpu slab
has been deactivated and contained free objects that were freed
remotely. It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/deactivate_to_head
@@ -170,9 +175,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file deactivate_to_head is read-only and specifies how
many times a partial cpu slab was deactivated and added to the
head of its node's partial list.
The deactivate_to_head file shows how many times a partial cpu
slab was deactivated and added to the head of its node's partial
list. It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/deactivate_to_tail
@@ -181,9 +186,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file deactivate_to_tail is read-only and specifies how
many times a partial cpu slab was deactivated and added to the
tail of its node's partial list.
The deactivate_to_tail file shows how many times a partial cpu
slab was deactivated and added to the tail of its node's partial
list. It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/destroy_by_rcu
@@ -201,9 +206,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file free_add_partial is read-only and specifies how many
times an object has been freed in a full slab so that it had to
added to its node's partial list.
The free_add_partial file shows how many times an object has
been freed in a full slab so that it had to added to its node's
partial list. It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/free_calls
@@ -222,9 +227,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The free_fastpath file is read-only and specifies how many
objects have been freed using the fast path because it was an
object from the cpu slab.
The free_fastpath file shows how many objects have been freed
using the fast path because it was an object from the cpu slab.
It can be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/free_frozen
@@ -233,9 +238,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The free_frozen file is read-only and specifies how many
objects have been freed to a frozen slab (i.e. a remote cpu
slab).
The free_frozen file shows how many objects have been freed to
a frozen slab (i.e. a remote cpu slab). It can be written to
clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/free_remove_partial
@@ -244,9 +249,10 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file free_remove_partial is read-only and specifies how
many times an object has been freed to a now-empty slab so
that it had to be removed from its node's partial list.
The free_remove_partial file shows how many times an object has
been freed to a now-empty slab so that it had to be removed from
its node's partial list. It can be written to clear the current
count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/free_slab
@@ -255,8 +261,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The free_slab file is read-only and specifies how many times an
empty slab has been freed back to the page allocator.
The free_slab file shows how many times an empty slab has been
freed back to the page allocator. It can be written to clear
the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/free_slowpath
@@ -265,9 +272,9 @@ KernelVersion: 2.6.25
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The free_slowpath file is read-only and specifies how many
objects have been freed using the slow path (i.e. to a full or
partial slab).
The free_slowpath file shows how many objects have been freed
using the slow path (i.e. to a full or partial slab). It can
be written to clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/hwcache_align
@@ -346,10 +353,10 @@ KernelVersion: 2.6.26
Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <cl@linux-foundation.org>
Description:
The file order_fallback is read-only and specifies how many
times an allocation of a new slab has not been possible at the
cache's order and instead fallen back to its minimum possible
order.
The order_fallback file shows how many times an allocation of a
new slab has not been possible at the cache's order and instead
fallen back to its minimum possible order. It can be written to
clear the current count.
Available when CONFIG_SLUB_STATS is enabled.
What: /sys/kernel/slab/cache/partial

44
Documentation/ABI/testing/sysfs-memory-page-offline Normal file
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@@ -0,0 +1,44 @@
What: /sys/devices/system/memory/soft_offline_page
Date: Sep 2009
KernelVersion: 2.6.33
Contact: andi@firstfloor.org
Description:
Soft-offline the memory page containing the physical address
written into this file. Input is a hex number specifying the
physical address of the page. The kernel will then attempt
to soft-offline it, by moving the contents elsewhere or
dropping it if possible. The kernel will then be placed
on the bad page list and never be reused.
The offlining is done in kernel specific granuality.
Normally it's the base page size of the kernel, but
this might change.
The page must be still accessible, not poisoned. The
kernel will never kill anything for this, but rather
fail the offline. Return value is the size of the
number, or a error when the offlining failed. Reading
the file is not allowed.
What: /sys/devices/system/memory/hard_offline_page
Date: Sep 2009
KernelVersion: 2.6.33
Contact: andi@firstfloor.org
Description:
Hard-offline the memory page containing the physical
address written into this file. Input is a hex number
specifying the physical address of the page. The
kernel will then attempt to hard-offline the page, by
trying to drop the page or killing any owner or
triggering IO errors if needed. Note this may kill
any processes owning the page. The kernel will avoid
to access this page assuming it's poisoned by the
hardware.
The offlining is done in kernel specific granuality.
Normally it's the base page size of the kernel, but
this might change.
Return value is the size of the number, or a error when
the offlining failed.
Reading the file is not allowed.

12
Documentation/ABI/testing/sysfs-platform-asus-laptop
View File

@@ -1,4 +1,4 @@
What: /sys/devices/platform/asus-laptop/display
What: /sys/devices/platform/asus_laptop/display
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@@ -13,7 +13,7 @@ Description:
Ex: - 0 (0000b) means no display
- 3 (0011b) CRT+LCD.
What: /sys/devices/platform/asus-laptop/gps
What: /sys/devices/platform/asus_laptop/gps
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@@ -21,7 +21,7 @@ Description:
Control the gps device. 1 means on, 0 means off.
Users: Lapsus
What: /sys/devices/platform/asus-laptop/ledd
What: /sys/devices/platform/asus_laptop/ledd
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@@ -29,11 +29,11 @@ Description:
Some models like the W1N have a LED display that can be
used to display several informations.
To control the LED display, use the following :
echo 0x0T000DDD > /sys/devices/platform/asus-laptop/
echo 0x0T000DDD > /sys/devices/platform/asus_laptop/
where T control the 3 letters display, and DDD the 3 digits display.
The DDD table can be found in Documentation/laptops/asus-laptop.txt
What: /sys/devices/platform/asus-laptop/bluetooth
What: /sys/devices/platform/asus_laptop/bluetooth
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@@ -42,7 +42,7 @@ Description:
This may control the led, the device or both.
Users: Lapsus
What: /sys/devices/platform/asus-laptop/wlan
What: /sys/devices/platform/asus_laptop/wlan
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>

10
Documentation/ABI/testing/sysfs-platform-eeepc-laptop
View File

@@ -1,4 +1,4 @@
What: /sys/devices/platform/eeepc-laptop/disp
What: /sys/devices/platform/eeepc/disp
Date: May 2008
KernelVersion: 2.6.26
Contact: "Corentin Chary" <corentincj@iksaif.net>
@@ -9,21 +9,21 @@ Description:
- 3 = LCD+CRT
If you run X11, you should use xrandr instead.
What: /sys/devices/platform/eeepc-laptop/camera
What: /sys/devices/platform/eeepc/camera
Date: May 2008
KernelVersion: 2.6.26
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Control the camera. 1 means on, 0 means off.
What: /sys/devices/platform/eeepc-laptop/cardr
What: /sys/devices/platform/eeepc/cardr
Date: May 2008
KernelVersion: 2.6.26
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Control the card reader. 1 means on, 0 means off.
What: /sys/devices/platform/eeepc-laptop/cpufv
What: /sys/devices/platform/eeepc/cpufv
Date: Jun 2009
KernelVersion: 2.6.31
Contact: "Corentin Chary" <corentincj@iksaif.net>
@@ -42,7 +42,7 @@ Description:
`------------ Availables modes
For example, 0x301 means: mode 1 selected, 3 available modes.
What: /sys/devices/platform/eeepc-laptop/available_cpufv
What: /sys/devices/platform/eeepc/available_cpufv
Date: Jun 2009
KernelVersion: 2.6.31
Contact: "Corentin Chary" <corentincj@iksaif.net>

13
Documentation/ABI/testing/sysfs-power
View File

@@ -101,3 +101,16 @@ Description:
CAUTION: Using it will cause your machine's real-time (CMOS)
clock to be set to a random invalid time after a resume.
What: /sys/power/pm_async
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/power/pm_async file controls the switch allowing the
user space to enable or disable asynchronous suspend and resume
of devices. If enabled, this feature will cause some device
drivers' suspend and resume callbacks to be executed in parallel
with each other and with the main suspend thread. It is enabled
if this file contains "1", which is the default. It may be
disabled by writing "0" to this file, in which case all devices
will be suspended and resumed synchronously.

38
Documentation/DocBook/Makefile
View File

@@ -8,7 +8,7 @@
DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \
kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
procfs-guide.xml writing_usb_driver.xml networking.xml \
writing_usb_driver.xml networking.xml \
kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
@@ -32,10 +32,10 @@ PS_METHOD = $(prefer-db2x)
###
# The targets that may be used.
PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs media
PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs xmldoclinks
BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))
xmldocs: $(BOOKS)
xmldocs: $(BOOKS) xmldoclinks
sgmldocs: xmldocs
PS := $(patsubst %.xml, %.ps, $(BOOKS))
@@ -45,15 +45,24 @@ PDF := $(patsubst %.xml, %.pdf, $(BOOKS))
pdfdocs: $(PDF)
HTML := $(sort $(patsubst %.xml, %.html, $(BOOKS)))
htmldocs: media $(HTML)
htmldocs: $(HTML)
$(call build_main_index)
$(call build_images)
MAN := $(patsubst %.xml, %.9, $(BOOKS))
mandocs: $(MAN)
media:
mkdir -p $(srctree)/Documentation/DocBook/media/
cp $(srctree)/Documentation/DocBook/dvb/*.png $(srctree)/Documentation/DocBook/v4l/*.gif $(srctree)/Documentation/DocBook/media/
build_images = mkdir -p $(objtree)/Documentation/DocBook/media/ && \
cp $(srctree)/Documentation/DocBook/dvb/*.png $(srctree)/Documentation/DocBook/v4l/*.gif $(objtree)/Documentation/DocBook/media/
xmldoclinks:
ifneq ($(objtree),$(srctree))
for dep in dvb media-entities.tmpl media-indices.tmpl v4l; do \
rm -f $(objtree)/Documentation/DocBook/$$dep \
&& ln -s $(srctree)/Documentation/DocBook/$$dep $(objtree)/Documentation/DocBook/ \
|| exit; \
done
endif
installmandocs: mandocs
mkdir -p /usr/local/man/man9/
@@ -65,7 +74,7 @@ KERNELDOC = $(srctree)/scripts/kernel-doc
DOCPROC = $(objtree)/scripts/basic/docproc
XMLTOFLAGS = -m $(srctree)/Documentation/DocBook/stylesheet.xsl
#XMLTOFLAGS += --skip-validation
XMLTOFLAGS += --skip-validation
###
# DOCPROC is used for two purposes:
@@ -101,17 +110,6 @@ endif
# Changes in kernel-doc force a rebuild of all documentation
$(BOOKS): $(KERNELDOC)
###
# procfs guide uses a .c file as example code.
# This requires an explicit dependency
C-procfs-example = procfs_example.xml
C-procfs-example2 = $(addprefix $(obj)/,$(C-procfs-example))
$(obj)/procfs-guide.xml: $(C-procfs-example2)
# List of programs to build
##oops, this is a kernel module::hostprogs-y := procfs_example
obj-m += procfs_example.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
@@ -238,7 +236,7 @@ clean-files := $(DOCBOOKS) \
$(patsubst %.xml, %.pdf, $(DOCBOOKS)) \
$(patsubst %.xml, %.html, $(DOCBOOKS)) \
$(patsubst %.xml, %.9, $(DOCBOOKS)) \
$(C-procfs-example) $(index)
$(index)
clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) man

2
Documentation/DocBook/device-drivers.tmpl
View File

@@ -45,7 +45,7 @@
</sect1>
<sect1><title>Atomic and pointer manipulation</title>
!Iarch/x86/include/asm/atomic_32.h
!Iarch/x86/include/asm/atomic.h
!Iarch/x86/include/asm/unaligned.h
</sect1>

2
Documentation/DocBook/deviceiobook.tmpl
View File

@@ -316,7 +316,7 @@ CPU B: spin_unlock_irqrestore(&amp;dev_lock, flags)
<chapter id="pubfunctions">
<title>Public Functions Provided</title>
!Iarch/x86/include/asm/io_32.h
!Iarch/x86/include/asm/io.h
!Elib/iomap.c
</chapter>

3
Documentation/DocBook/mac80211.tmpl
View File

@@ -144,7 +144,7 @@ usage should require reading the full document.
this though and the recommendation to allow only a single
interface in STA mode at first!
</para>
!Finclude/net/mac80211.h ieee80211_if_init_conf
!Finclude/net/mac80211.h ieee80211_vif
</chapter>
<chapter id="rx-tx">
@@ -234,7 +234,6 @@ usage should require reading the full document.
<title>Multiple queues and QoS support</title>
<para>TBD</para>
!Finclude/net/mac80211.h ieee80211_tx_queue_params
!Finclude/net/mac80211.h ieee80211_tx_queue_stats
</chapter>
<chapter id="AP">

18
Documentation/DocBook/media-entities.tmpl
View File

@@ -23,6 +23,7 @@
<!ENTITY VIDIOC-ENUMINPUT "<link linkend='vidioc-enuminput'><constant>VIDIOC_ENUMINPUT</constant></link>">
<!ENTITY VIDIOC-ENUMOUTPUT "<link linkend='vidioc-enumoutput'><constant>VIDIOC_ENUMOUTPUT</constant></link>">
<!ENTITY VIDIOC-ENUMSTD "<link linkend='vidioc-enumstd'><constant>VIDIOC_ENUMSTD</constant></link>">
<!ENTITY VIDIOC-ENUM-DV-PRESETS "<link linkend='vidioc-enum-dv-presets'><constant>VIDIOC_ENUM_DV_PRESETS</constant></link>">
<!ENTITY VIDIOC-ENUM-FMT "<link linkend='vidioc-enum-fmt'><constant>VIDIOC_ENUM_FMT</constant></link>">
<!ENTITY VIDIOC-ENUM-FRAMEINTERVALS "<link linkend='vidioc-enum-frameintervals'><constant>VIDIOC_ENUM_FRAMEINTERVALS</constant></link>">
<!ENTITY VIDIOC-ENUM-FRAMESIZES "<link linkend='vidioc-enum-framesizes'><constant>VIDIOC_ENUM_FRAMESIZES</constant></link>">
@@ -30,6 +31,8 @@
<!ENTITY VIDIOC-G-AUDOUT "<link linkend='vidioc-g-audioout'><constant>VIDIOC_G_AUDOUT</constant></link>">
<!ENTITY VIDIOC-G-CROP "<link linkend='vidioc-g-crop'><constant>VIDIOC_G_CROP</constant></link>">
<!ENTITY VIDIOC-G-CTRL "<link linkend='vidioc-g-ctrl'><constant>VIDIOC_G_CTRL</constant></link>">
<!ENTITY VIDIOC-G-DV-PRESET "<link linkend='vidioc-g-dv-preset'><constant>VIDIOC_G_DV_PRESET</constant></link>">
<!ENTITY VIDIOC-G-DV-TIMINGS "<link linkend='vidioc-g-dv-timings'><constant>VIDIOC_G_DV_TIMINGS</constant></link>">
<!ENTITY VIDIOC-G-ENC-INDEX "<link linkend='vidioc-g-enc-index'><constant>VIDIOC_G_ENC_INDEX</constant></link>">
<!ENTITY VIDIOC-G-EXT-CTRLS "<link linkend='vidioc-g-ext-ctrls'><constant>VIDIOC_G_EXT_CTRLS</constant></link>">
<!ENTITY VIDIOC-G-FBUF "<link linkend='vidioc-g-fbuf'><constant>VIDIOC_G_FBUF</constant></link>">
@@ -53,6 +56,7 @@
<!ENTITY VIDIOC-QUERYCTRL "<link linkend='vidioc-queryctrl'><constant>VIDIOC_QUERYCTRL</constant></link>">
<!ENTITY VIDIOC-QUERYMENU "<link linkend='vidioc-queryctrl'><constant>VIDIOC_QUERYMENU</constant></link>">
<!ENTITY VIDIOC-QUERYSTD "<link linkend='vidioc-querystd'><constant>VIDIOC_QUERYSTD</constant></link>">
<!ENTITY VIDIOC-QUERY-DV-PRESET "<link linkend='vidioc-query-dv-preset'><constant>VIDIOC_QUERY_DV_PRESET</constant></link>">
<!ENTITY VIDIOC-REQBUFS "<link linkend='vidioc-reqbufs'><constant>VIDIOC_REQBUFS</constant></link>">
<!ENTITY VIDIOC-STREAMOFF "<link linkend='vidioc-streamon'><constant>VIDIOC_STREAMOFF</constant></link>">
<!ENTITY VIDIOC-STREAMON "<link linkend='vidioc-streamon'><constant>VIDIOC_STREAMON</constant></link>">
@@ -60,6 +64,8 @@
<!ENTITY VIDIOC-S-AUDOUT "<link linkend='vidioc-g-audioout'><constant>VIDIOC_S_AUDOUT</constant></link>">
<!ENTITY VIDIOC-S-CROP "<link linkend='vidioc-g-crop'><constant>VIDIOC_S_CROP</constant></link>">
<!ENTITY VIDIOC-S-CTRL "<link linkend='vidioc-g-ctrl'><constant>VIDIOC_S_CTRL</constant></link>">
<!ENTITY VIDIOC-S-DV-PRESET "<link linkend='vidioc-g-dv-preset'><constant>VIDIOC_S_DV_PRESET</constant></link>">
<!ENTITY VIDIOC-S-DV-TIMINGS "<link linkend='vidioc-g-dv-timings'><constant>VIDIOC_S_DV_TIMINGS</constant></link>">
<!ENTITY VIDIOC-S-EXT-CTRLS "<link linkend='vidioc-g-ext-ctrls'><constant>VIDIOC_S_EXT_CTRLS</constant></link>">
<!ENTITY VIDIOC-S-FBUF "<link linkend='vidioc-g-fbuf'><constant>VIDIOC_S_FBUF</constant></link>">
<!ENTITY VIDIOC-S-FMT "<link linkend='vidioc-g-fmt'><constant>VIDIOC_S_FMT</constant></link>">
@@ -118,6 +124,7 @@
<!-- Structures -->
<!ENTITY v4l2-audio "struct&nbsp;<link linkend='v4l2-audio'>v4l2_audio</link>">
<!ENTITY v4l2-audioout "struct&nbsp;<link linkend='v4l2-audioout'>v4l2_audioout</link>">
<!ENTITY v4l2-bt-timings "struct&nbsp;<link linkend='v4l2-bt-timings'>v4l2_bt_timings</link>">
<!ENTITY v4l2-buffer "struct&nbsp;<link linkend='v4l2-buffer'>v4l2_buffer</link>">
<!ENTITY v4l2-capability "struct&nbsp;<link linkend='v4l2-capability'>v4l2_capability</link>">
<!ENTITY v4l2-captureparm "struct&nbsp;<link linkend='v4l2-captureparm'>v4l2_captureparm</link>">
@@ -128,6 +135,9 @@
<!ENTITY v4l2-dbg-chip-ident "struct&nbsp;<link linkend='v4l2-dbg-chip-ident'>v4l2_dbg_chip_ident</link>">
<!ENTITY v4l2-dbg-match "struct&nbsp;<link linkend='v4l2-dbg-match'>v4l2_dbg_match</link>">
<!ENTITY v4l2-dbg-register "struct&nbsp;<link linkend='v4l2-dbg-register'>v4l2_dbg_register</link>">
<!ENTITY v4l2-dv-enum-preset "struct&nbsp;<link linkend='v4l2-dv-enum-preset'>v4l2_dv_enum_preset</link>">
<!ENTITY v4l2-dv-preset "struct&nbsp;<link linkend='v4l2-dv-preset'>v4l2_dv_preset</link>">
<!ENTITY v4l2-dv-timings "struct&nbsp;<link linkend='v4l2-dv-timings'>v4l2_dv_timings</link>">
<!ENTITY v4l2-enc-idx "struct&nbsp;<link linkend='v4l2-enc-idx'>v4l2_enc_idx</link>">
<!ENTITY v4l2-enc-idx-entry "struct&nbsp;<link linkend='v4l2-enc-idx-entry'>v4l2_enc_idx_entry</link>">
<!ENTITY v4l2-encoder-cmd "struct&nbsp;<link linkend='v4l2-encoder-cmd'>v4l2_encoder_cmd</link>">
@@ -243,6 +253,10 @@
<!ENTITY sub-enumaudioout SYSTEM "v4l/vidioc-enumaudioout.xml">
<!ENTITY sub-enuminput SYSTEM "v4l/vidioc-enuminput.xml">
<!ENTITY sub-enumoutput SYSTEM "v4l/vidioc-enumoutput.xml">
<!ENTITY sub-enum-dv-presets SYSTEM "v4l/vidioc-enum-dv-presets.xml">
<!ENTITY sub-g-dv-preset SYSTEM "v4l/vidioc-g-dv-preset.xml">
<!ENTITY sub-query-dv-preset SYSTEM "v4l/vidioc-query-dv-preset.xml">
<!ENTITY sub-g-dv-timings SYSTEM "v4l/vidioc-g-dv-timings.xml">
<!ENTITY sub-enumstd SYSTEM "v4l/vidioc-enumstd.xml">
<!ENTITY sub-g-audio SYSTEM "v4l/vidioc-g-audio.xml">
<!ENTITY sub-g-audioout SYSTEM "v4l/vidioc-g-audioout.xml">
@@ -333,6 +347,10 @@
<!ENTITY enumaudioout SYSTEM "v4l/vidioc-enumaudioout.xml">
<!ENTITY enuminput SYSTEM "v4l/vidioc-enuminput.xml">
<!ENTITY enumoutput SYSTEM "v4l/vidioc-enumoutput.xml">
<!ENTITY enum-dv-presets SYSTEM "v4l/vidioc-enum-dv-presets.xml">
<!ENTITY g-dv-preset SYSTEM "v4l/vidioc-g-dv-preset.xml">
<!ENTITY query-dv-preset SYSTEM "v4l/vidioc-query-dv-preset.xml">
<!ENTITY g-dv-timings SYSTEM "v4l/vidioc-g-dv-timings.xml">
<!ENTITY enumstd SYSTEM "v4l/vidioc-enumstd.xml">
<!ENTITY g-audio SYSTEM "v4l/vidioc-g-audio.xml">
<!ENTITY g-audioout SYSTEM "v4l/vidioc-g-audioout.xml">

4
Documentation/DocBook/media-indices.tmpl
View File

@@ -36,6 +36,7 @@
<indexentry><primaryie>enum&nbsp;<link linkend='v4l2-preemphasis'>v4l2_preemphasis</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-audio'>v4l2_audio</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-audioout'>v4l2_audioout</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-bt-timings'>v4l2_bt_timings</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-buffer'>v4l2_buffer</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-capability'>v4l2_capability</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-captureparm'>v4l2_captureparm</link></primaryie></indexentry>
@@ -46,6 +47,9 @@
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-dbg-chip-ident'>v4l2_dbg_chip_ident</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-dbg-match'>v4l2_dbg_match</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-dbg-register'>v4l2_dbg_register</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-dv-enum-preset'>v4l2_dv_enum_preset</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-dv-preset'>v4l2_dv_preset</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-dv-timings'>v4l2_dv_timings</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-enc-idx'>v4l2_enc_idx</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-enc-idx-entry'>v4l2_enc_idx_entry</link></primaryie></indexentry>
<indexentry><primaryie>struct&nbsp;<link linkend='v4l2-encoder-cmd'>v4l2_encoder_cmd</link></primaryie></indexentry>

12
Documentation/DocBook/mtdnand.tmpl
View File

@@ -174,7 +174,7 @@
</para>
<programlisting>
static struct mtd_info *board_mtd;
static unsigned long baseaddr;
static void __iomem *baseaddr;
</programlisting>
<para>
Static example
@@ -182,7 +182,7 @@ static unsigned long baseaddr;
<programlisting>
static struct mtd_info board_mtd;
static struct nand_chip board_chip;
static unsigned long baseaddr;
static void __iomem *baseaddr;
</programlisting>
</sect1>
<sect1 id="Partition_defines">
@@ -283,8 +283,8 @@ int __init board_init (void)
}
/* map physical address */
baseaddr = (unsigned long)ioremap(CHIP_PHYSICAL_ADDRESS, 1024);
if(!baseaddr){
baseaddr = ioremap(CHIP_PHYSICAL_ADDRESS, 1024);
if (!baseaddr) {
printk("Ioremap to access NAND chip failed\n");
err = -EIO;
goto out_mtd;
@@ -316,7 +316,7 @@ int __init board_init (void)
goto out;
out_ior:
iounmap((void *)baseaddr);
iounmap(baseaddr);
out_mtd:
kfree (board_mtd);
out:
@@ -341,7 +341,7 @@ static void __exit board_cleanup (void)
nand_release (board_mtd);
/* unmap physical address */
iounmap((void *)baseaddr);
iounmap(baseaddr);
/* Free the MTD device structure */
kfree (board_mtd);

626
Documentation/DocBook/procfs-guide.tmpl
View File

@@ -1,626 +0,0 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" [
<!ENTITY procfsexample SYSTEM "procfs_example.xml">
]>
<book id="LKProcfsGuide">
<bookinfo>
<title>Linux Kernel Procfs Guide</title>
<authorgroup>
<author>
<firstname>Erik</firstname>
<othername>(J.A.K.)</othername>
<surname>Mouw</surname>
<affiliation>
<address>
<email>mouw@nl.linux.org</email>
</address>
</affiliation>
</author>
<othercredit>
<contrib>
This software and documentation were written while working on the
LART computing board
(<ulink url="http://www.lartmaker.nl/">http://www.lartmaker.nl/</ulink>),
which was sponsored by the Delt University of Technology projects
Mobile Multi-media Communications and Ubiquitous Communications.
</contrib>
</othercredit>
</authorgroup>
<revhistory>
<revision>
<revnumber>1.0</revnumber>
<date>May 30, 2001</date>
<revremark>Initial revision posted to linux-kernel</revremark>
</revision>
<revision>
<revnumber>1.1</revnumber>
<date>June 3, 2001</date>
<revremark>Revised after comments from linux-kernel</revremark>
</revision>
</revhistory>
<copyright>
<year>2001</year>
<holder>Erik Mouw</holder>
</copyright>
<legalnotice>
<para>
This documentation is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
</para>
<para>
This documentation is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU General Public License for more details.
</para>
<para>
You should have received a copy of the GNU General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
</para>
<para>
For more details see the file COPYING in the source
distribution of Linux.
</para>
</legalnotice>
</bookinfo>
<toc>
</toc>
<preface id="Preface">
<title>Preface</title>
<para>
This guide describes the use of the procfs file system from
within the Linux kernel. The idea to write this guide came up on
the #kernelnewbies IRC channel (see <ulink
url="http://www.kernelnewbies.org/">http://www.kernelnewbies.org/</ulink>),
when Jeff Garzik explained the use of procfs and forwarded me a
message Alexander Viro wrote to the linux-kernel mailing list. I
agreed to write it up nicely, so here it is.
</para>
<para>
I'd like to thank Jeff Garzik
<email>jgarzik@pobox.com</email> and Alexander Viro
<email>viro@parcelfarce.linux.theplanet.co.uk</email> for their input,
Tim Waugh <email>twaugh@redhat.com</email> for his <ulink
url="http://people.redhat.com/twaugh/docbook/selfdocbook/">Selfdocbook</ulink>,
and Marc Joosen <email>marcj@historia.et.tudelft.nl</email> for
proofreading.
</para>
<para>
Erik
</para>
</preface>
<chapter id="intro">
<title>Introduction</title>
<para>
The <filename class="directory">/proc</filename> file system
(procfs) is a special file system in the linux kernel. It's a
virtual file system: it is not associated with a block device
but exists only in memory. The files in the procfs are there to
allow userland programs access to certain information from the
kernel (like process information in <filename
class="directory">/proc/[0-9]+/</filename>), but also for debug
purposes (like <filename>/proc/ksyms</filename>).
</para>
<para>
This guide describes the use of the procfs file system from
within the Linux kernel. It starts by introducing all relevant
functions to manage the files within the file system. After that
it shows how to communicate with userland, and some tips and
tricks will be pointed out. Finally a complete example will be
shown.
</para>
<para>
Note that the files in <filename
class="directory">/proc/sys</filename> are sysctl files: they
don't belong to procfs and are governed by a completely
different API described in the Kernel API book.
</para>
</chapter>
<chapter id="managing">
<title>Managing procfs entries</title>
<para>
This chapter describes the functions that various kernel
components use to populate the procfs with files, symlinks,
device nodes, and directories.
</para>
<para>
A minor note before we start: if you want to use any of the
procfs functions, be sure to include the correct header file!
This should be one of the first lines in your code:
</para>
<programlisting>
#include &lt;linux/proc_fs.h&gt;
</programlisting>
<sect1 id="regularfile">
<title>Creating a regular file</title>
<funcsynopsis>
<funcprototype>
<funcdef>struct proc_dir_entry* <function>create_proc_entry</function></funcdef>
<paramdef>const char* <parameter>name</parameter></paramdef>
<paramdef>mode_t <parameter>mode</parameter></paramdef>
<paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
This function creates a regular file with the name
<parameter>name</parameter>, file mode
<parameter>mode</parameter> in the directory
<parameter>parent</parameter>. To create a file in the root of
the procfs, use <constant>NULL</constant> as
<parameter>parent</parameter> parameter. When successful, the
function will return a pointer to the freshly created
<structname>struct proc_dir_entry</structname>; otherwise it
will return <constant>NULL</constant>. <xref
linkend="userland"/> describes how to do something useful with
regular files.
</para>
<para>
Note that it is specifically supported that you can pass a
path that spans multiple directories. For example
<function>create_proc_entry</function>(<parameter>"drivers/via0/info"</parameter>)
will create the <filename class="directory">via0</filename>
directory if necessary, with standard
<constant>0755</constant> permissions.
</para>
<para>
If you only want to be able to read the file, the function
<function>create_proc_read_entry</function> described in <xref
linkend="convenience"/> may be used to create and initialise
the procfs entry in one single call.
</para>
</sect1>
<sect1 id="Creating_a_symlink">
<title>Creating a symlink</title>
<funcsynopsis>
<funcprototype>
<funcdef>struct proc_dir_entry*
<function>proc_symlink</function></funcdef> <paramdef>const
char* <parameter>name</parameter></paramdef>
<paramdef>struct proc_dir_entry*
<parameter>parent</parameter></paramdef> <paramdef>const
char* <parameter>dest</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
This creates a symlink in the procfs directory
<parameter>parent</parameter> that points from
<parameter>name</parameter> to
<parameter>dest</parameter>. This translates in userland to
<literal>ln -s</literal> <parameter>dest</parameter>
<parameter>name</parameter>.
</para>
</sect1>
<sect1 id="Creating_a_directory">
<title>Creating a directory</title>
<funcsynopsis>
<funcprototype>
<funcdef>struct proc_dir_entry* <function>proc_mkdir</function></funcdef>
<paramdef>const char* <parameter>name</parameter></paramdef>
<paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
Create a directory <parameter>name</parameter> in the procfs
directory <parameter>parent</parameter>.
</para>
</sect1>
<sect1 id="Removing_an_entry">
<title>Removing an entry</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>remove_proc_entry</function></funcdef>
<paramdef>const char* <parameter>name</parameter></paramdef>
<paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
Removes the entry <parameter>name</parameter> in the directory
<parameter>parent</parameter> from the procfs. Entries are
removed by their <emphasis>name</emphasis>, not by the
<structname>struct proc_dir_entry</structname> returned by the
various create functions. Note that this function doesn't
recursively remove entries.
</para>
<para>
Be sure to free the <structfield>data</structfield> entry from
the <structname>struct proc_dir_entry</structname> before
<function>remove_proc_entry</function> is called (that is: if
there was some <structfield>data</structfield> allocated, of
course). See <xref linkend="usingdata"/> for more information
on using the <structfield>data</structfield> entry.
</para>
</sect1>
</chapter>
<chapter id="userland">
<title>Communicating with userland</title>
<para>
Instead of reading (or writing) information directly from
kernel memory, procfs works with <emphasis>call back
functions</emphasis> for files: functions that are called when
a specific file is being read or written. Such functions have
to be initialised after the procfs file is created by setting
the <structfield>read_proc</structfield> and/or
<structfield>write_proc</structfield> fields in the
<structname>struct proc_dir_entry*</structname> that the
function <function>create_proc_entry</function> returned:
</para>
<programlisting>
struct proc_dir_entry* entry;
entry->read_proc = read_proc_foo;
entry->write_proc = write_proc_foo;
</programlisting>
<para>
If you only want to use a the
<structfield>read_proc</structfield>, the function
<function>create_proc_read_entry</function> described in <xref
linkend="convenience"/> may be used to create and initialise the
procfs entry in one single call.
</para>
<sect1 id="Reading_data">
<title>Reading data</title>
<para>
The read function is a call back function that allows userland
processes to read data from the kernel. The read function
should have the following format:
</para>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>read_func</function></funcdef>
<paramdef>char* <parameter>buffer</parameter></paramdef>
<paramdef>char** <parameter>start</parameter></paramdef>
<paramdef>off_t <parameter>off</parameter></paramdef>
<paramdef>int <parameter>count</parameter></paramdef>
<paramdef>int* <parameter>peof</parameter></paramdef>
<paramdef>void* <parameter>data</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
The read function should write its information into the
<parameter>buffer</parameter>, which will be exactly
<literal>PAGE_SIZE</literal> bytes long.
</para>
<para>
The parameter
<parameter>peof</parameter> should be used to signal that the
end of the file has been reached by writing
<literal>1</literal> to the memory location
<parameter>peof</parameter> points to.
</para>
<para>
The <parameter>data</parameter>
parameter can be used to create a single call back function for
several files, see <xref linkend="usingdata"/>.
</para>
<para>
The rest of the parameters and the return value are described
by a comment in <filename>fs/proc/generic.c</filename> as follows:
</para>
<blockquote>
<para>
You have three ways to return data:
</para>
<orderedlist>
<listitem>
<para>
Leave <literal>*start = NULL</literal>. (This is the default.)
Put the data of the requested offset at that
offset within the buffer. Return the number (<literal>n</literal>)
of bytes there are from the beginning of the
buffer up to the last byte of data. If the
number of supplied bytes (<literal>= n - offset</literal>) is
greater than zero and you didn't signal eof
and the reader is prepared to take more data
you will be called again with the requested
offset advanced by the number of bytes
absorbed. This interface is useful for files
no larger than the buffer.
</para>
</listitem>
<listitem>
<para>
Set <literal>*start</literal> to an unsigned long value less than
the buffer address but greater than zero.
Put the data of the requested offset at the
beginning of the buffer. Return the number of
bytes of data placed there. If this number is
greater than zero and you didn't signal eof
and the reader is prepared to take more data
you will be called again with the requested
offset advanced by <literal>*start</literal>. This interface is
useful when you have a large file consisting
of a series of blocks which you want to count
and return as wholes.
(Hack by Paul.Russell@rustcorp.com.au)
</para>
</listitem>
<listitem>
<para>
Set <literal>*start</literal> to an address within the buffer.
Put the data of the requested offset at <literal>*start</literal>.
Return the number of bytes of data placed there.
If this number is greater than zero and you
didn't signal eof and the reader is prepared to
take more data you will be called again with the
requested offset advanced by the number of bytes
absorbed.
</para>
</listitem>
</orderedlist>
</blockquote>
<para>
<xref linkend="example"/> shows how to use a read call back
function.
</para>
</sect1>
<sect1 id="Writing_data">
<title>Writing data</title>
<para>
The write call back function allows a userland process to write
data to the kernel, so it has some kind of control over the
kernel. The write function should have the following format:
</para>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>write_func</function></funcdef>
<paramdef>struct file* <parameter>file</parameter></paramdef>
<paramdef>const char* <parameter>buffer</parameter></paramdef>
<paramdef>unsigned long <parameter>count</parameter></paramdef>
<paramdef>void* <parameter>data</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
The write function should read <parameter>count</parameter>
bytes at maximum from the <parameter>buffer</parameter>. Note
that the <parameter>buffer</parameter> doesn't live in the
kernel's memory space, so it should first be copied to kernel
space with <function>copy_from_user</function>. The
<parameter>file</parameter> parameter is usually
ignored. <xref linkend="usingdata"/> shows how to use the
<parameter>data</parameter> parameter.
</para>
<para>
Again, <xref linkend="example"/> shows how to use this call back
function.
</para>
</sect1>
<sect1 id="usingdata">
<title>A single call back for many files</title>
<para>
When a large number of almost identical files is used, it's
quite inconvenient to use a separate call back function for
each file. A better approach is to have a single call back
function that distinguishes between the files by using the
<structfield>data</structfield> field in <structname>struct
proc_dir_entry</structname>. First of all, the
<structfield>data</structfield> field has to be initialised:
</para>
<programlisting>
struct proc_dir_entry* entry;
struct my_file_data *file_data;
file_data = kmalloc(sizeof(struct my_file_data), GFP_KERNEL);
entry->data = file_data;
</programlisting>
<para>
The <structfield>data</structfield> field is a <type>void
*</type>, so it can be initialised with anything.
</para>
<para>
Now that the <structfield>data</structfield> field is set, the
<function>read_proc</function> and
<function>write_proc</function> can use it to distinguish
between files because they get it passed into their
<parameter>data</parameter> parameter:
</para>
<programlisting>
int foo_read_func(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
int len;
if(data == file_data) {
/* special case for this file */
} else {
/* normal processing */
}
return len;
}
</programlisting>
<para>
Be sure to free the <structfield>data</structfield> data field
when removing the procfs entry.
</para>
</sect1>
</chapter>
<chapter id="tips">
<title>Tips and tricks</title>
<sect1 id="convenience">
<title>Convenience functions</title>
<funcsynopsis>
<funcprototype>
<funcdef>struct proc_dir_entry* <function>create_proc_read_entry</function></funcdef>
<paramdef>const char* <parameter>name</parameter></paramdef>
<paramdef>mode_t <parameter>mode</parameter></paramdef>
<paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef>
<paramdef>read_proc_t* <parameter>read_proc</parameter></paramdef>
<paramdef>void* <parameter>data</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
This function creates a regular file in exactly the same way
as <function>create_proc_entry</function> from <xref
linkend="regularfile"/> does, but also allows to set the read
function <parameter>read_proc</parameter> in one call. This
function can set the <parameter>data</parameter> as well, like
explained in <xref linkend="usingdata"/>.
</para>
</sect1>
<sect1 id="Modules">
<title>Modules</title>
<para>
If procfs is being used from within a module, be sure to set
the <structfield>owner</structfield> field in the
<structname>struct proc_dir_entry</structname> to
<constant>THIS_MODULE</constant>.
</para>
<programlisting>
struct proc_dir_entry* entry;
entry->owner = THIS_MODULE;
</programlisting>
</sect1>
<sect1 id="Mode_and_ownership">
<title>Mode and ownership</title>
<para>
Sometimes it is useful to change the mode and/or ownership of
a procfs entry. Here is an example that shows how to achieve
that:
</para>
<programlisting>
struct proc_dir_entry* entry;
entry->mode = S_IWUSR |S_IRUSR | S_IRGRP | S_IROTH;
entry->uid = 0;
entry->gid = 100;
</programlisting>
</sect1>
</chapter>
<chapter id="example">
<title>Example</title>
<!-- be careful with the example code: it shouldn't be wider than
approx. 60 columns, or otherwise it won't fit properly on a page
-->
&procfsexample;
</chapter>
</book>

201
Documentation/DocBook/procfs_example.c
View File

@@ -1,201 +0,0 @@
/*
* procfs_example.c: an example proc interface
*
* Copyright (C) 2001, Erik Mouw (mouw@nl.linux.org)
*
* This file accompanies the procfs-guide in the Linux kernel
* source. Its main use is to demonstrate the concepts and
* functions described in the guide.
*
* This software has been developed while working on the LART
* computing board (http://www.lartmaker.nl), which was sponsored
* by the Delt University of Technology projects Mobile Multi-media
* Communications and Ubiquitous Communications.
*
* This program is free software; you can redistribute
* it and/or modify it under the terms of the GNU General
* Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place,
* Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/jiffies.h>
#include <asm/uaccess.h>
#define MODULE_VERS "1.0"
#define MODULE_NAME "procfs_example"
#define FOOBAR_LEN 8
struct fb_data_t {
char name[FOOBAR_LEN + 1];
char value[FOOBAR_LEN + 1];
};
static struct proc_dir_entry *example_dir, *foo_file,
*bar_file, *jiffies_file, *symlink;
struct fb_data_t foo_data, bar_data;
static int proc_read_jiffies(char *page, char **start,
off_t off, int count,
int *eof, void *data)
{
int len;
len = sprintf(page, "jiffies = %ld\n",
jiffies);
return len;
}
static int proc_read_foobar(char *page, char **start,
off_t off, int count,
int *eof, void *data)
{
int len;
struct fb_data_t *fb_data = (struct fb_data_t *)data;
/* DON'T DO THAT - buffer overruns are bad */
len = sprintf(page, "%s = '%s'\n",
fb_data->name, fb_data->value);
return len;
}
static int proc_write_foobar(struct file *file,
const char *buffer,
unsigned long count,
void *data)
{
int len;
struct fb_data_t *fb_data = (struct fb_data_t *)data;
if(count > FOOBAR_LEN)
len = FOOBAR_LEN;
else
len = count;
if(copy_from_user(fb_data->value, buffer, len))
return -EFAULT;
fb_data->value[len] = '\0';
return len;
}
static int __init init_procfs_example(void)
{
int rv = 0;
/* create directory */
example_dir = proc_mkdir(MODULE_NAME, NULL);
if(example_dir == NULL) {
rv = -ENOMEM;
goto out;
}
/* create jiffies using convenience function */
jiffies_file = create_proc_read_entry("jiffies",
0444, example_dir,
proc_read_jiffies,
NULL);
if(jiffies_file == NULL) {
rv = -ENOMEM;
goto no_jiffies;
}
/* create foo and bar files using same callback
* functions
*/
foo_file = create_proc_entry("foo", 0644, example_dir);
if(foo_file == NULL) {
rv = -ENOMEM;
goto no_foo;
}
strcpy(foo_data.name, "foo");
strcpy(foo_data.value, "foo");
foo_file->data = &foo_data;
foo_file->read_proc = proc_read_foobar;
foo_file->write_proc = proc_write_foobar;
bar_file = create_proc_entry("bar", 0644, example_dir);
if(bar_file == NULL) {
rv = -ENOMEM;
goto no_bar;
}
strcpy(bar_data.name, "bar");
strcpy(bar_data.value, "bar");
bar_file->data = &bar_data;
bar_file->read_proc = proc_read_foobar;
bar_file->write_proc = proc_write_foobar;
/* create symlink */
symlink = proc_symlink("jiffies_too", example_dir,
"jiffies");
if(symlink == NULL) {
rv = -ENOMEM;
goto no_symlink;
}
/* everything OK */
printk(KERN_INFO "%s %s initialised\n",
MODULE_NAME, MODULE_VERS);
return 0;
no_symlink:
remove_proc_entry("bar", example_dir);
no_bar:
remove_proc_entry("foo", example_dir);
no_foo:
remove_proc_entry("jiffies", example_dir);
no_jiffies:
remove_proc_entry(MODULE_NAME, NULL);
out:
return rv;
}
static void __exit cleanup_procfs_example(void)
{
remove_proc_entry("jiffies_too", example_dir);
remove_proc_entry("bar", example_dir);
remove_proc_entry("foo", example_dir);
remove_proc_entry("jiffies", example_dir);
remove_proc_entry(MODULE_NAME, NULL);
printk(KERN_INFO "%s %s removed\n",
MODULE_NAME, MODULE_VERS);
}
module_init(init_procfs_example);
module_exit(cleanup_procfs_example);
MODULE_AUTHOR("Erik Mouw");
MODULE_DESCRIPTION("procfs examples");
MODULE_LICENSE("GPL");

35
Documentation/DocBook/v4l/common.xml
View File

@@ -716,6 +716,41 @@ if (-1 == ioctl (fd, &VIDIOC-S-STD;, &amp;std_id)) {
}
</programlisting>
</example>
<section id="dv-timings">
<title>Digital Video (DV) Timings</title>
<para>
The video standards discussed so far has been dealing with Analog TV and the
corresponding video timings. Today there are many more different hardware interfaces
such as High Definition TV interfaces (HDMI), VGA, DVI connectors etc., that carry
video signals and there is a need to extend the API to select the video timings
for these interfaces. Since it is not possible to extend the &v4l2-std-id; due to
the limited bits available, a new set of IOCTLs is added to set/get video timings at
the input and output: </para><itemizedlist>
<listitem>
<para>DV Presets: Digital Video (DV) presets. These are IDs representing a
video timing at the input/output. Presets are pre-defined timings implemented
by the hardware according to video standards. A __u32 data type is used to represent
a preset unlike the bit mask that is used in &v4l2-std-id; allowing future extensions
to support as many different presets as needed.</para>
</listitem>
<listitem>
<para>Custom DV Timings: This will allow applications to define more detailed
custom video timings for the interface. This includes parameters such as width, height,
polarities, frontporch, backporch etc.
</para>
</listitem>
</itemizedlist>
<para>To enumerate and query the attributes of DV presets supported by a device,
applications use the &VIDIOC-ENUM-DV-PRESETS; ioctl. To get the current DV preset,
applications use the &VIDIOC-G-DV-PRESET; ioctl and to set a preset they use the
&VIDIOC-S-DV-PRESET; ioctl.</para>
<para>To set custom DV timings for the device, applications use the
&VIDIOC-S-DV-TIMINGS; ioctl and to get current custom DV timings they use the
&VIDIOC-G-DV-TIMINGS; ioctl.</para>
<para>Applications can make use of the <xref linkend="input-capabilities" /> and
<xref linkend="output-capabilities"/> flags to decide what ioctls are available to set the
video timings for the device.</para>
</section>
</section>
&sub-controls;

16
Documentation/DocBook/v4l/compat.xml
View File

@@ -2291,8 +2291,8 @@ was renamed to <structname id="v4l2-chip-ident-old">v4l2_chip_ident_old</structn
<listitem>
<para>New control <constant>V4L2_CID_COLORFX</constant> was added.</para>
</listitem>
</orderedlist>
</section>
</orderedlist>
</section>
<section>
<title>V4L2 in Linux 2.6.32</title>
<orderedlist>
@@ -2322,8 +2322,16 @@ more information.</para>
<listitem>
<para>Added Remote Controller chapter, describing the default Remote Controller mapping for media devices.</para>
</listitem>
</orderedlist>
</section>
</orderedlist>
</section>
<section>
<title>V4L2 in Linux 2.6.33</title>
<orderedlist>
<listitem>
<para>Added support for Digital Video timings in order to support HDTV receivers and transmitters.</para>
</listitem>
</orderedlist>
</section>
</section>
<section id="other">

3
Documentation/DocBook/v4l/io.xml
View File

@@ -589,7 +589,8 @@ number of a video input as in &v4l2-input; field
<entry></entry>
<entry>A place holder for future extensions and custom
(driver defined) buffer types
<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher.</entry>
<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher. Applications
should set this to 0.</entry>
</row>
</tbody>
</tgroup>

26
Documentation/DocBook/v4l/v4l2.xml
View File

@@ -74,6 +74,17 @@ Remote Controller chapter.</contrib>
</address>
</affiliation>
</author>
<author>
<firstname>Muralidharan</firstname>
<surname>Karicheri</surname>
<contrib>Documented the Digital Video timings API.</contrib>
<affiliation>
<address>
<email>m-karicheri2@ti.com</email>
</address>
</affiliation>
</author>
</authorgroup>
<copyright>
@@ -89,7 +100,7 @@ Remote Controller chapter.</contrib>
<year>2008</year>
<year>2009</year>
<holder>Bill Dirks, Michael H. Schimek, Hans Verkuil, Martin
Rubli, Andy Walls, Mauro Carvalho Chehab</holder>
Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab</holder>
</copyright>
<legalnotice>
<para>Except when explicitly stated as GPL, programming examples within
@@ -102,6 +113,13 @@ structs, ioctls) must be noted in more detail in the history chapter
(compat.sgml), along with the possible impact on existing drivers and
applications. -->
<revision>
<revnumber>2.6.33</revnumber>
<date>2009-12-03</date>
<authorinitials>mk</authorinitials>
<revremark>Added documentation for the Digital Video timings API.</revremark>
</revision>
<revision>
<revnumber>2.6.32</revnumber>
<date>2009-08-31</date>
@@ -355,7 +373,7 @@ and discussions on the V4L mailing list.</revremark>
</partinfo>
<title>Video for Linux Two API Specification</title>
<subtitle>Revision 2.6.32</subtitle>
<subtitle>Revision 2.6.33</subtitle>
<chapter id="common">
&sub-common;
@@ -411,6 +429,7 @@ and discussions on the V4L mailing list.</revremark>
&sub-encoder-cmd;
&sub-enumaudio;
&sub-enumaudioout;
&sub-enum-dv-presets;
&sub-enum-fmt;
&sub-enum-framesizes;
&sub-enum-frameintervals;
@@ -421,6 +440,8 @@ and discussions on the V4L mailing list.</revremark>
&sub-g-audioout;
&sub-g-crop;
&sub-g-ctrl;
&sub-g-dv-preset;
&sub-g-dv-timings;
&sub-g-enc-index;
&sub-g-ext-ctrls;
&sub-g-fbuf;
@@ -441,6 +462,7 @@ and discussions on the V4L mailing list.</revremark>
&sub-querybuf;
&sub-querycap;
&sub-queryctrl;
&sub-query-dv-preset;
&sub-querystd;
&sub-reqbufs;
&sub-s-hw-freq-seek;

116
Documentation/DocBook/v4l/videodev2.h.xml
View File

@@ -733,6 +733,99 @@ struct <link linkend="v4l2-standard">v4l2_standard</link> {
__u32 reserved[4];
};
/*
* V I D E O T I M I N G S D V P R E S E T
*/
struct <link linkend="v4l2-dv-preset">v4l2_dv_preset</link> {
__u32 preset;
__u32 reserved[4];
};
/*
* D V P R E S E T S E N U M E R A T I O N
*/
struct <link linkend="v4l2-dv-enum-preset">v4l2_dv_enum_preset</link> {
__u32 index;
__u32 preset;
__u8 name[32]; /* Name of the preset timing */
__u32 width;
__u32 height;
__u32 reserved[4];
};
/*
* D V P R E S E T V A L U E S
*/
#define V4L2_DV_INVALID 0
#define V4L2_DV_480P59_94 1 /* BT.1362 */
#define V4L2_DV_576P50 2 /* BT.1362 */
#define V4L2_DV_720P24 3 /* SMPTE 296M */
#define V4L2_DV_720P25 4 /* SMPTE 296M */
#define V4L2_DV_720P30 5 /* SMPTE 296M */
#define V4L2_DV_720P50 6 /* SMPTE 296M */
#define V4L2_DV_720P59_94 7 /* SMPTE 274M */
#define V4L2_DV_720P60 8 /* SMPTE 274M/296M */
#define V4L2_DV_1080I29_97 9 /* BT.1120/ SMPTE 274M */
#define V4L2_DV_1080I30 10 /* BT.1120/ SMPTE 274M */
#define V4L2_DV_1080I25 11 /* BT.1120 */
#define V4L2_DV_1080I50 12 /* SMPTE 296M */
#define V4L2_DV_1080I60 13 /* SMPTE 296M */
#define V4L2_DV_1080P24 14 /* SMPTE 296M */
#define V4L2_DV_1080P25 15 /* SMPTE 296M */
#define V4L2_DV_1080P30 16 /* SMPTE 296M */
#define V4L2_DV_1080P50 17 /* BT.1120 */
#define V4L2_DV_1080P60 18 /* BT.1120 */
/*
* D V B T T I M I N G S
*/
/* BT.656/BT.1120 timing data */
struct <link linkend="v4l2-bt-timings">v4l2_bt_timings</link> {
__u32 width; /* width in pixels */
__u32 height; /* height in lines */
__u32 interlaced; /* Interlaced or progressive */
__u32 polarities; /* Positive or negative polarity */
__u64 pixelclock; /* Pixel clock in HZ. Ex. 74.25MHz-&gt;74250000 */
__u32 hfrontporch; /* Horizpontal front porch in pixels */
__u32 hsync; /* Horizontal Sync length in pixels */
__u32 hbackporch; /* Horizontal back porch in pixels */
__u32 vfrontporch; /* Vertical front porch in pixels */
__u32 vsync; /* Vertical Sync length in lines */
__u32 vbackporch; /* Vertical back porch in lines */
__u32 il_vfrontporch; /* Vertical front porch for bottom field of
* interlaced field formats
*/
__u32 il_vsync; /* Vertical sync length for bottom field of
* interlaced field formats
*/
__u32 il_vbackporch; /* Vertical back porch for bottom field of
* interlaced field formats
*/
__u32 reserved[16];
} __attribute__ ((packed));
/* Interlaced or progressive format */
#define V4L2_DV_PROGRESSIVE 0
#define V4L2_DV_INTERLACED 1
/* Polarities. If bit is not set, it is assumed to be negative polarity */
#define V4L2_DV_VSYNC_POS_POL 0x00000001
#define V4L2_DV_HSYNC_POS_POL 0x00000002
/* DV timings */
struct <link linkend="v4l2-dv-timings">v4l2_dv_timings</link> {
__u32 type;
union {
struct <link linkend="v4l2-bt-timings">v4l2_bt_timings</link> bt;
__u32 reserved[32];
};
} __attribute__ ((packed));
/* Values for the type field */
#define V4L2_DV_BT_656_1120 0 /* BT.656/1120 timing type */
/*
* V I D E O I N P U T S
*/
@@ -744,7 +837,8 @@ struct <link linkend="v4l2-input">v4l2_input</link> {
__u32 tuner; /* Associated tuner */
v4l2_std_id std;
__u32 status;
__u32 reserved[4];
__u32 capabilities;
__u32 reserved[3];
};
/* Values for the 'type' field */
@@ -775,6 +869,11 @@ struct <link linkend="v4l2-input">v4l2_input</link> {
#define V4L2_IN_ST_NO_ACCESS 0x02000000 /* Conditional access denied */
#define V4L2_IN_ST_VTR 0x04000000 /* VTR time constant */
/* capabilities flags */
#define V4L2_IN_CAP_PRESETS 0x00000001 /* Supports S_DV_PRESET */
#define V4L2_IN_CAP_CUSTOM_TIMINGS 0x00000002 /* Supports S_DV_TIMINGS */
#define V4L2_IN_CAP_STD 0x00000004 /* Supports S_STD */
/*
* V I D E O O U T P U T S
*/
@@ -785,13 +884,19 @@ struct <link linkend="v4l2-output">v4l2_output</link> {
__u32 audioset; /* Associated audios (bitfield) */
__u32 modulator; /* Associated modulator */
v4l2_std_id std;
__u32 reserved[4];
__u32 capabilities;
__u32 reserved[3];
};
/* Values for the 'type' field */
#define V4L2_OUTPUT_TYPE_MODULATOR 1
#define V4L2_OUTPUT_TYPE_ANALOG 2
#define V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY 3
/* capabilities flags */
#define V4L2_OUT_CAP_PRESETS 0x00000001 /* Supports S_DV_PRESET */
#define V4L2_OUT_CAP_CUSTOM_TIMINGS 0x00000002 /* Supports S_DV_TIMINGS */
#define V4L2_OUT_CAP_STD 0x00000004 /* Supports S_STD */
/*
* C O N T R O L S
*/
@@ -1626,6 +1731,13 @@ struct <link linkend="v4l2-dbg-chip-ident">v4l2_dbg_chip_ident</link> {
#endif
#define VIDIOC_S_HW_FREQ_SEEK _IOW('V', 82, struct <link linkend="v4l2-hw-freq-seek">v4l2_hw_freq_seek</link>)
#define VIDIOC_ENUM_DV_PRESETS _IOWR('V', 83, struct <link linkend="v4l2-dv-enum-preset">v4l2_dv_enum_preset</link>)
#define VIDIOC_S_DV_PRESET _IOWR('V', 84, struct <link linkend="v4l2-dv-preset">v4l2_dv_preset</link>)
#define VIDIOC_G_DV_PRESET _IOWR('V', 85, struct <link linkend="v4l2-dv-preset">v4l2_dv_preset</link>)
#define VIDIOC_QUERY_DV_PRESET _IOR('V', 86, struct <link linkend="v4l2-dv-preset">v4l2_dv_preset</link>)
#define VIDIOC_S_DV_TIMINGS _IOWR('V', 87, struct <link linkend="v4l2-dv-timings">v4l2_dv_timings</link>)
#define VIDIOC_G_DV_TIMINGS _IOWR('V', 88, struct <link linkend="v4l2-dv-timings">v4l2_dv_timings</link>)
/* Reminder: when adding new ioctls please add support for them to
drivers/media/video/v4l2-compat-ioctl32.c as well! */

238
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@@ -0,0 +1,238 @@
<refentry id="vidioc-enum-dv-presets">
<refmeta>
<refentrytitle>ioctl VIDIOC_ENUM_DV_PRESETS</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_ENUM_DV_PRESETS</refname>
<refpurpose>Enumerate supported Digital Video presets</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct v4l2_dv_enum_preset *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>VIDIOC_ENUM_DV_PRESETS</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>To query the attributes of a DV preset, applications initialize the
<structfield>index</structfield> field and zero the reserved array of &v4l2-dv-enum-preset;
and call the <constant>VIDIOC_ENUM_DV_PRESETS</constant> ioctl with a pointer to this
structure. Drivers fill the rest of the structure or return an
&EINVAL; when the index is out of bounds. To enumerate all DV Presets supported,
applications shall begin at index zero, incrementing by one until the
driver returns <errorcode>EINVAL</errorcode>. Drivers may enumerate a
different set of DV presets after switching the video input or
output.</para>
<table pgwide="1" frame="none" id="v4l2-dv-enum-preset">
<title>struct <structname>v4l2_dv_enum_presets</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>index</structfield></entry>
<entry>Number of the DV preset, set by the
application.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>preset</structfield></entry>
<entry>This field identifies one of the DV preset values listed in <xref linkend="v4l2-dv-presets-vals"/>.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>name</structfield>[24]</entry>
<entry>Name of the preset, a NUL-terminated ASCII string, for example: "720P-60", "1080I-60". This information is
intended for the user.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>width</structfield></entry>
<entry>Width of the active video in pixels for the DV preset.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>height</structfield></entry>
<entry>Height of the active video in lines for the DV preset.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[4]</entry>
<entry>Reserved for future extensions. Drivers must set the array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="v4l2-dv-presets-vals">
<title>struct <structname>DV Presets</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>Preset</entry>
<entry>Preset value</entry>
<entry>Description</entry>
</row>
<row>
<entry></entry>
<entry></entry>
<entry></entry>
</row>
<row>
<entry>V4L2_DV_INVALID</entry>
<entry>0</entry>
<entry>Invalid preset value.</entry>
</row>
<row>
<entry>V4L2_DV_480P59_94</entry>
<entry>1</entry>
<entry>720x480 progressive video at 59.94 fps as per BT.1362.</entry>
</row>
<row>
<entry>V4L2_DV_576P50</entry>
<entry>2</entry>
<entry>720x576 progressive video at 50 fps as per BT.1362.</entry>
</row>
<row>
<entry>V4L2_DV_720P24</entry>
<entry>3</entry>
<entry>1280x720 progressive video at 24 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_720P25</entry>
<entry>4</entry>
<entry>1280x720 progressive video at 25 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_720P30</entry>
<entry>5</entry>
<entry>1280x720 progressive video at 30 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_720P50</entry>
<entry>6</entry>
<entry>1280x720 progressive video at 50 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_720P59_94</entry>
<entry>7</entry>
<entry>1280x720 progressive video at 59.94 fps as per SMPTE 274M.</entry>
</row>
<row>
<entry>V4L2_DV_720P60</entry>
<entry>8</entry>
<entry>1280x720 progressive video at 60 fps as per SMPTE 274M/296M.</entry>
</row>
<row>
<entry>V4L2_DV_1080I29_97</entry>
<entry>9</entry>
<entry>1920x1080 interlaced video at 29.97 fps as per BT.1120/SMPTE 274M.</entry>
</row>
<row>
<entry>V4L2_DV_1080I30</entry>
<entry>10</entry>
<entry>1920x1080 interlaced video at 30 fps as per BT.1120/SMPTE 274M.</entry>
</row>
<row>
<entry>V4L2_DV_1080I25</entry>
<entry>11</entry>
<entry>1920x1080 interlaced video at 25 fps as per BT.1120.</entry>
</row>
<row>
<entry>V4L2_DV_1080I50</entry>
<entry>12</entry>
<entry>1920x1080 interlaced video at 50 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_1080I60</entry>
<entry>13</entry>
<entry>1920x1080 interlaced video at 60 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_1080P24</entry>
<entry>14</entry>
<entry>1920x1080 progressive video at 24 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_1080P25</entry>
<entry>15</entry>
<entry>1920x1080 progressive video at 25 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_1080P30</entry>
<entry>16</entry>
<entry>1920x1080 progressive video at 30 fps as per SMPTE 296M.</entry>
</row>
<row>
<entry>V4L2_DV_1080P50</entry>
<entry>17</entry>
<entry>1920x1080 progressive video at 50 fps as per BT.1120.</entry>
</row>
<row>
<entry>V4L2_DV_1080P60</entry>
<entry>18</entry>
<entry>1920x1080 progressive video at 60 fps as per BT.1120.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>The &v4l2-dv-enum-preset; <structfield>index</structfield>
is out of bounds.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
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-->

36
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@@ -124,7 +124,13 @@ current input.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[4]</entry>
<entry><structfield>capabilities</structfield></entry>
<entry>This field provides capabilities for the
input. See <xref linkend="input-capabilities" /> for flags.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[3]</entry>
<entry>Reserved for future extensions. Drivers must set
the array to zero.</entry>
</row>
@@ -261,6 +267,34 @@ flag is set Macrovision has been detected.</entry>
</tbody>
</tgroup>
</table>
<!-- Capability flags based on video timings RFC by Muralidharan
Karicheri, titled RFC (v1.2): V4L - Support for video timings at the
input/output interface to linux-media@vger.kernel.org on 19 Oct 2009.
-->
<table frame="none" pgwide="1" id="input-capabilities">
<title>Input capabilities</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>V4L2_IN_CAP_PRESETS</constant></entry>
<entry>0x00000001</entry>
<entry>This input supports setting DV presets by using VIDIOC_S_DV_PRESET.</entry>
</row>
<row>
<entry><constant>V4L2_OUT_CAP_CUSTOM_TIMINGS</constant></entry>
<entry>0x00000002</entry>
<entry>This input supports setting custom video timings by using VIDIOC_S_DV_TIMINGS.</entry>
</row>
<row>
<entry><constant>V4L2_IN_CAP_STD</constant></entry>
<entry>0x00000004</entry>
<entry>This input supports setting the TV standard by using VIDIOC_S_STD.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>

36
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View File

@@ -114,7 +114,13 @@ details on video standards and how to switch see <xref
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[4]</entry>
<entry><structfield>capabilities</structfield></entry>
<entry>This field provides capabilities for the
output. See <xref linkend="output-capabilities" /> for flags.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[3]</entry>
<entry>Reserved for future extensions. Drivers must set
the array to zero.</entry>
</row>
@@ -147,6 +153,34 @@ CVBS, S-Video, RGB.</entry>
</tgroup>
</table>
<!-- Capabilities flags based on video timings RFC by Muralidharan
Karicheri, titled RFC (v1.2): V4L - Support for video timings at the
input/output interface to linux-media@vger.kernel.org on 19 Oct 2009.
-->
<table frame="none" pgwide="1" id="output-capabilities">
<title>Output capabilities</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>V4L2_OUT_CAP_PRESETS</constant></entry>
<entry>0x00000001</entry>
<entry>This output supports setting DV presets by using VIDIOC_S_DV_PRESET.</entry>
</row>
<row>
<entry><constant>V4L2_OUT_CAP_CUSTOM_TIMINGS</constant></entry>
<entry>0x00000002</entry>
<entry>This output supports setting custom video timings by using VIDIOC_S_DV_TIMINGS.</entry>
</row>
<row>
<entry><constant>V4L2_OUT_CAP_STD</constant></entry>
<entry>0x00000004</entry>
<entry>This output supports setting the TV standard by using VIDIOC_S_STD.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;

111
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@@ -0,0 +1,111 @@
<refentry id="vidioc-g-dv-preset">
<refmeta>
<refentrytitle>ioctl VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_G_DV_PRESET</refname>
<refname>VIDIOC_S_DV_PRESET</refname>
<refpurpose>Query or select the DV preset of the current input or output</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>&v4l2-dv-preset;
*<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>To query and select the current DV preset, applications
use the <constant>VIDIOC_G_DV_PRESET</constant> and <constant>VIDIOC_S_DV_PRESET</constant>
ioctls which take a pointer to a &v4l2-dv-preset; type as argument.
Applications must zero the reserved array in &v4l2-dv-preset;.
<constant>VIDIOC_G_DV_PRESET</constant> returns a dv preset in the field
<structfield>preset</structfield> of &v4l2-dv-preset;.</para>
<para><constant>VIDIOC_S_DV_PRESET</constant> accepts a pointer to a &v4l2-dv-preset;
that has the preset value to be set. Applications must zero the reserved array in &v4l2-dv-preset;.
If the preset is not supported, it returns an &EINVAL; </para>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>This ioctl is not supported, or the
<constant>VIDIOC_S_DV_PRESET</constant>,<constant>VIDIOC_S_DV_PRESET</constant> parameter was unsuitable.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>The device is busy and therefore can not change the preset.</para>
</listitem>
</varlistentry>
</variablelist>
<table pgwide="1" frame="none" id="v4l2-dv-preset">
<title>struct <structname>v4l2_dv_preset</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>preset</structfield></entry>
<entry>Preset value to represent the digital video timings</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved[4]</structfield></entry>
<entry>Reserved fields for future use</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
</refentry>
<!--
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@@ -0,0 +1,224 @@
<refentry id="vidioc-g-dv-timings">
<refmeta>
<refentrytitle>ioctl VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_G_DV_TIMINGS</refname>
<refname>VIDIOC_S_DV_TIMINGS</refname>
<refpurpose>Get or set custom DV timings for input or output</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>&v4l2-dv-timings;
*<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>To set custom DV timings for the input or output, applications use the
<constant>VIDIOC_S_DV_TIMINGS</constant> ioctl and to get the current custom timings,
applications use the <constant>VIDIOC_G_DV_TIMINGS</constant> ioctl. The detailed timing
information is filled in using the structure &v4l2-dv-timings;. These ioctls take
a pointer to the &v4l2-dv-timings; structure as argument. If the ioctl is not supported
or the timing values are not correct, the driver returns &EINVAL;.</para>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>This ioctl is not supported, or the
<constant>VIDIOC_S_DV_TIMINGS</constant> parameter was unsuitable.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>The device is busy and therefore can not change the timings.</para>
</listitem>
</varlistentry>
</variablelist>
<table pgwide="1" frame="none" id="v4l2-bt-timings">
<title>struct <structname>v4l2_bt_timings</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>width</structfield></entry>
<entry>Width of the active video in pixels</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>height</structfield></entry>
<entry>Height of the active video in lines</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>interlaced</structfield></entry>
<entry>Progressive (0) or interlaced (1)</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>polarities</structfield></entry>
<entry>This is a bit mask that defines polarities of sync signals.
bit 0 (V4L2_DV_VSYNC_POS_POL) is for vertical sync polarity and bit 1 (V4L2_DV_HSYNC_POS_POL) is for horizontal sync polarity. If the bit is set
(1) it is positive polarity and if is cleared (0), it is negative polarity.</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>pixelclock</structfield></entry>
<entry>Pixel clock in Hz. Ex. 74.25MHz->74250000</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>hfrontporch</structfield></entry>
<entry>Horizontal front porch in pixels</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>hsync</structfield></entry>
<entry>Horizontal sync length in pixels</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>hbackporch</structfield></entry>
<entry>Horizontal back porch in pixels</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>vfrontporch</structfield></entry>
<entry>Vertical front porch in lines</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>vsync</structfield></entry>
<entry>Vertical sync length in lines</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>vbackporch</structfield></entry>
<entry>Vertical back porch in lines</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>il_vfrontporch</structfield></entry>
<entry>Vertical front porch in lines for bottom field of interlaced field formats</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>il_vsync</structfield></entry>
<entry>Vertical sync length in lines for bottom field of interlaced field formats</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>il_vbackporch</structfield></entry>
<entry>Vertical back porch in lines for bottom field of interlaced field formats</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="v4l2-dv-timings">
<title>struct <structname>v4l2_dv_timings</structname></title>
<tgroup cols="4">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>type</structfield></entry>
<entry></entry>
<entry>Type of DV timings as listed in <xref linkend="dv-timing-types"/>.</entry>
</row>
<row>
<entry>union</entry>
<entry><structfield></structfield></entry>
<entry></entry>
</row>
<row>
<entry></entry>
<entry>&v4l2-bt-timings;</entry>
<entry><structfield>bt</structfield></entry>
<entry>Timings defined by BT.656/1120 specifications</entry>
</row>
<row>
<entry></entry>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[32]</entry>
<entry></entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="dv-timing-types">
<title>DV Timing types</title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>Timing type</entry>
<entry>value</entry>
<entry>Description</entry>
</row>
<row>
<entry></entry>
<entry></entry>
<entry></entry>
</row>
<row>
<entry>V4L2_DV_BT_656_1120</entry>
<entry>0</entry>
<entry>BT.656/1120 timings</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
</refentry>
<!--
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6
Documentation/DocBook/v4l/vidioc-g-std.xml
View File

@@ -86,6 +86,12 @@ standards.</para>
<constant>VIDIOC_S_STD</constant> parameter was unsuitable.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>The device is busy and therefore can not change the standard</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>

40
Documentation/DocBook/v4l/vidioc-qbuf.xml
View File

@@ -54,12 +54,10 @@ to enqueue an empty (capturing) or filled (output) buffer in the
driver's incoming queue. The semantics depend on the selected I/O
method.</para>
<para>To enqueue a <link linkend="mmap">memory mapped</link>
buffer applications set the <structfield>type</structfield> field of a
&v4l2-buffer; to the same buffer type as previously &v4l2-format;
<structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>, the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_MMAP</constant> and the
<para>To enqueue a buffer applications set the <structfield>type</structfield>
field of a &v4l2-buffer; to the same buffer type as was previously used
with &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>. Applications must also set the
<structfield>index</structfield> field. Valid index numbers range from
zero to the number of buffers allocated with &VIDIOC-REQBUFS;
(&v4l2-requestbuffers; <structfield>count</structfield>) minus one. The
@@ -70,8 +68,19 @@ intended for output (<structfield>type</structfield> is
<constant>V4L2_BUF_TYPE_VBI_OUTPUT</constant>) applications must also
initialize the <structfield>bytesused</structfield>,
<structfield>field</structfield> and
<structfield>timestamp</structfield> fields. See <xref
linkend="buffer" /> for details. When
<structfield>timestamp</structfield> fields, see <xref
linkend="buffer" /> for details.
Applications must also set <structfield>flags</structfield> to 0. If a driver
supports capturing from specific video inputs and you want to specify a video
input, then <structfield>flags</structfield> should be set to
<constant>V4L2_BUF_FLAG_INPUT</constant> and the field
<structfield>input</structfield> must be initialized to the desired input.
The <structfield>reserved</structfield> field must be set to 0.
</para>
<para>To enqueue a <link linkend="mmap">memory mapped</link>
buffer applications set the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_MMAP</constant>. When
<constant>VIDIOC_QBUF</constant> is called with a pointer to this
structure the driver sets the
<constant>V4L2_BUF_FLAG_MAPPED</constant> and
@@ -81,14 +90,10 @@ structure the driver sets the
&EINVAL;.</para>
<para>To enqueue a <link linkend="userp">user pointer</link>
buffer applications set the <structfield>type</structfield> field of a
&v4l2-buffer; to the same buffer type as previously &v4l2-format;
<structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>, the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_USERPTR</constant> and the
buffer applications set the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_USERPTR</constant>, the
<structfield>m.userptr</structfield> field to the address of the
buffer and <structfield>length</structfield> to its size. When the
buffer is intended for output additional fields must be set as above.
buffer and <structfield>length</structfield> to its size.
When <constant>VIDIOC_QBUF</constant> is called with a pointer to this
structure the driver sets the <constant>V4L2_BUF_FLAG_QUEUED</constant>
flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and
@@ -96,13 +101,14 @@ flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and
<structfield>flags</structfield> field, or it returns an error code.
This ioctl locks the memory pages of the buffer in physical memory,
they cannot be swapped out to disk. Buffers remain locked until
dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl are
dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is
called, or until the device is closed.</para>
<para>Applications call the <constant>VIDIOC_DQBUF</constant>
ioctl to dequeue a filled (capturing) or displayed (output) buffer
from the driver's outgoing queue. They just set the
<structfield>type</structfield> and <structfield>memory</structfield>
<structfield>type</structfield>, <structfield>memory</structfield>
and <structfield>reserved</structfield>
fields of a &v4l2-buffer; as above, when <constant>VIDIOC_DQBUF</constant>
is called with a pointer to this structure the driver fills the
remaining fields or returns an error code.</para>

85
Documentation/DocBook/v4l/vidioc-query-dv-preset.xml Normal file
View File

@@ -0,0 +1,85 @@
<refentry id="vidioc-query-dv-preset">
<refmeta>
<refentrytitle>ioctl VIDIOC_QUERY_DV_PRESET</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_QUERY_DV_PRESET</refname>
<refpurpose>Sense the DV preset received by the current
input</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>&v4l2-dv-preset; *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>VIDIOC_QUERY_DV_PRESET</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>The hardware may be able to detect the current DV preset
automatically, similar to sensing the video standard. To do so, applications
call <constant> VIDIOC_QUERY_DV_PRESET</constant> with a pointer to a
&v4l2-dv-preset; type. Once the hardware detects a preset, that preset is
returned in the preset field of &v4l2-dv-preset;. When detection is not
possible or fails, the value V4L2_DV_INVALID is returned.</para>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>This ioctl is not supported.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>The device is busy and therefore can not sense the preset</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
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sgml-parent-document: "v4l2.sgml"
indent-tabs-mode: nil
End:
-->

7
Documentation/DocBook/v4l/vidioc-querybuf.xml
View File

@@ -54,12 +54,13 @@ buffer at any time after buffers have been allocated with the
&VIDIOC-REQBUFS; ioctl.</para>
<para>Applications set the <structfield>type</structfield> field
of a &v4l2-buffer; to the same buffer type as previously
of a &v4l2-buffer; to the same buffer type as was previously used with
&v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>, and the <structfield>index</structfield>
field. Valid index numbers range from zero
to the number of buffers allocated with &VIDIOC-REQBUFS;
(&v4l2-requestbuffers; <structfield>count</structfield>) minus one.
The <structfield>reserved</structfield> field should to set to 0.
After calling <constant>VIDIOC_QUERYBUF</constant> with a pointer to
this structure drivers return an error code or fill the rest of
the structure.</para>
@@ -68,8 +69,8 @@ the structure.</para>
<constant>V4L2_BUF_FLAG_MAPPED</constant>,
<constant>V4L2_BUF_FLAG_QUEUED</constant> and
<constant>V4L2_BUF_FLAG_DONE</constant> flags will be valid. The
<structfield>memory</structfield> field will be set to
<constant>V4L2_MEMORY_MMAP</constant>, the <structfield>m.offset</structfield>
<structfield>memory</structfield> field will be set to the current
I/O method, the <structfield>m.offset</structfield>
contains the offset of the buffer from the start of the device memory,
the <structfield>length</structfield> field its size. The driver may
or may not set the remaining fields and flags, they are meaningless in

6
Documentation/DocBook/v4l/vidioc-querystd.xml
View File

@@ -70,6 +70,12 @@ current video input or output.</para>
<para>This ioctl is not supported.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>The device is busy and therefore can not detect the standard</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>

36
Documentation/DocBook/v4l/vidioc-reqbufs.xml
View File

@@ -54,23 +54,23 @@ I/O. Memory mapped buffers are located in device memory and must be
allocated with this ioctl before they can be mapped into the
application's address space. User buffers are allocated by
applications themselves, and this ioctl is merely used to switch the
driver into user pointer I/O mode.</para>
driver into user pointer I/O mode and to setup some internal structures.</para>
<para>To allocate device buffers applications initialize three
fields of a <structname>v4l2_requestbuffers</structname> structure.
<para>To allocate device buffers applications initialize all
fields of the <structname>v4l2_requestbuffers</structname> structure.
They set the <structfield>type</structfield> field to the respective
stream or buffer type, the <structfield>count</structfield> field to
the desired number of buffers, and <structfield>memory</structfield>
must be set to <constant>V4L2_MEMORY_MMAP</constant>. When the ioctl
is called with a pointer to this structure the driver attempts to
allocate the requested number of buffers and stores the actual number
the desired number of buffers, <structfield>memory</structfield>
must be set to the requested I/O method and the reserved array
must be zeroed. When the ioctl
is called with a pointer to this structure the driver will attempt to allocate
the requested number of buffers and it stores the actual number
allocated in the <structfield>count</structfield> field. It can be
smaller than the number requested, even zero, when the driver runs out
of free memory. A larger number is possible when the driver requires
more buffers to function correctly.<footnote>
<para>For example video output requires at least two buffers,
of free memory. A larger number is also possible when the driver requires
more buffers to function correctly. For example video output requires at least two buffers,
one displayed and one filled by the application.</para>
</footnote> When memory mapping I/O is not supported the ioctl
<para>When the I/O method is not supported the ioctl
returns an &EINVAL;.</para>
<para>Applications can call <constant>VIDIOC_REQBUFS</constant>
@@ -81,14 +81,6 @@ in progress, an implicit &VIDIOC-STREAMOFF;. <!-- mhs: I see no
reason why munmap()ping one or even all buffers must imply
streamoff.--></para>
<para>To negotiate user pointer I/O, applications initialize only
the <structfield>type</structfield> field and set
<structfield>memory</structfield> to
<constant>V4L2_MEMORY_USERPTR</constant>. When the ioctl is called
with a pointer to this structure the driver prepares for user pointer
I/O, when this I/O method is not supported the ioctl returns an
&EINVAL;.</para>
<table pgwide="1" frame="none" id="v4l2-requestbuffers">
<title>struct <structname>v4l2_requestbuffers</structname></title>
<tgroup cols="3">
@@ -97,9 +89,7 @@ I/O, when this I/O method is not supported the ioctl returns an
<row>
<entry>__u32</entry>
<entry><structfield>count</structfield></entry>
<entry>The number of buffers requested or granted. This
field is only used when <structfield>memory</structfield> is set to
<constant>V4L2_MEMORY_MMAP</constant>.</entry>
<entry>The number of buffers requested or granted.</entry>
</row>
<row>
<entry>&v4l2-buf-type;</entry>
@@ -120,7 +110,7 @@ as the &v4l2-format; <structfield>type</structfield> field. See <xref
<entry><structfield>reserved</structfield>[2]</entry>
<entry>A place holder for future extensions and custom
(driver defined) buffer types <constant>V4L2_BUF_TYPE_PRIVATE</constant> and
higher.</entry>
higher. This array should be zeroed by applications.</entry>
</row>
</tbody>
</tgroup>

2
Documentation/IO-mapping.txt
View File

@@ -157,7 +157,7 @@ For such memory, you can do things like
* access only the 640k-1MB area, so anything else
* has to be remapped.
*/
char * baseptr = ioremap(0xFC000000, 1024*1024);
void __iomem *baseptr = ioremap(0xFC000000, 1024*1024);
/* write a 'A' to the offset 10 of the area */
writeb('A',baseptr+10);

0
Documentation/DMA-mapping.txt → Documentation/PCI/PCI-DMA-mapping.txt
View File

10
Documentation/RCU/00-INDEX
View File

@@ -6,16 +6,22 @@ checklist.txt
- Review Checklist for RCU Patches
listRCU.txt
- Using RCU to Protect Read-Mostly Linked Lists
lockdep.txt
- RCU and lockdep checking
NMI-RCU.txt
- Using RCU to Protect Dynamic NMI Handlers
rcubarrier.txt
- RCU and Unloadable Modules
rculist_nulls.txt
- RCU list primitives for use with SLAB_DESTROY_BY_RCU
rcuref.txt
- Reference-count design for elements of lists/arrays protected by RCU
rcu.txt
- RCU Concepts
rcubarrier.txt
- Unloading modules that use RCU callbacks
RTFP.txt
- List of RCU papers (bibliography) going back to 1980.
stallwarn.txt
- RCU CPU stall warnings (CONFIG_RCU_CPU_STALL_DETECTOR)
torture.txt
- RCU Torture Test Operation (CONFIG_RCU_TORTURE_TEST)
trace.txt

61
Documentation/RCU/RTFP.txt
View File

@@ -25,10 +25,10 @@ to be referencing the data structure. However, this mechanism was not
optimized for modern computer systems, which is not surprising given
that these overheads were not so expensive in the mid-80s. Nonetheless,
passive serialization appears to be the first deferred-destruction
mechanism to be used in production. Furthermore, the relevant patent has
lapsed, so this approach may be used in non-GPL software, if desired.
(In contrast, use of RCU is permitted only in software licensed under
GPL. Sorry!!!)
mechanism to be used in production. Furthermore, the relevant patent
has lapsed, so this approach may be used in non-GPL software, if desired.
(In contrast, implementation of RCU is permitted only in software licensed
under either GPL or LGPL. Sorry!!!)
In 1990, Pugh [Pugh90] noted that explicitly tracking which threads
were reading a given data structure permitted deferred free to operate
@@ -150,6 +150,18 @@ preemptible RCU [PaulEMcKenney2007PreemptibleRCU], and the three-part
LWN "What is RCU?" series [PaulEMcKenney2007WhatIsRCUFundamentally,
PaulEMcKenney2008WhatIsRCUUsage, and PaulEMcKenney2008WhatIsRCUAPI].
2008 saw a journal paper on real-time RCU [DinakarGuniguntala2008IBMSysJ],
a history of how Linux changed RCU more than RCU changed Linux
[PaulEMcKenney2008RCUOSR], and a design overview of hierarchical RCU
[PaulEMcKenney2008HierarchicalRCU].
2009 introduced user-level RCU algorithms [PaulEMcKenney2009MaliciousURCU],
which Mathieu Desnoyers is now maintaining [MathieuDesnoyers2009URCU]
[MathieuDesnoyersPhD]. TINY_RCU [PaulEMcKenney2009BloatWatchRCU] made
its appearance, as did expedited RCU [PaulEMcKenney2009expeditedRCU].
The problem of resizeable RCU-protected hash tables may now be on a path
to a solution [JoshTriplett2009RPHash].
Bibtex Entries
@article{Kung80
@@ -730,6 +742,11 @@ Revised:
"
}
#
# "What is RCU?" LWN series.
#
########################################################################
@article{DinakarGuniguntala2008IBMSysJ
,author="D. Guniguntala and P. E. McKenney and J. Triplett and J. Walpole"
,title="The read-copy-update mechanism for supporting real-time applications on shared-memory multiprocessor systems with {Linux}"
@@ -820,3 +837,39 @@ Revised:
Uniprocessor assumptions allow simplified RCU implementation.
"
}
@unpublished{PaulEMcKenney2009expeditedRCU
,Author="Paul E. McKenney"
,Title="[{PATCH} -tip 0/3] expedited 'big hammer' {RCU} grace periods"
,month="June"
,day="25"
,year="2009"
,note="Available:
\url{http://lkml.org/lkml/2009/6/25/306}
[Viewed August 16, 2009]"
,annotation="
First posting of expedited RCU to be accepted into -tip.
"
}
@unpublished{JoshTriplett2009RPHash
,Author="Josh Triplett"
,Title="Scalable concurrent hash tables via relativistic programming"
,month="September"
,year="2009"
,note="Linux Plumbers Conference presentation"
,annotation="
RP fun with hash tables.
"
}
@phdthesis{MathieuDesnoyersPhD
, title = "Low-Impact Operating System Tracing"
, author = "Mathieu Desnoyers"
, school = "Ecole Polytechnique de Montr\'{e}al"
, month = "December"
, year = 2009
,note="Available:
\url{http://www.lttng.org/pub/thesis/desnoyers-dissertation-2009-12.pdf}
[Viewed December 9, 2009]"
}

204
Documentation/RCU/checklist.txt
View File

@@ -8,13 +8,12 @@ would cause. This list is based on experiences reviewing such patches
over a rather long period of time, but improvements are always welcome!
0. Is RCU being applied to a read-mostly situation? If the data
structure is updated more than about 10% of the time, then
you should strongly consider some other approach, unless
detailed performance measurements show that RCU is nonetheless
the right tool for the job. Yes, you might think of RCU
as simply cutting overhead off of the readers and imposing it
on the writers. That is exactly why normal uses of RCU will
do much more reading than updating.
structure is updated more than about 10% of the time, then you
should strongly consider some other approach, unless detailed
performance measurements show that RCU is nonetheless the right
tool for the job. Yes, RCU does reduce read-side overhead by
increasing write-side overhead, which is exactly why normal uses
of RCU will do much more reading than updating.
Another exception is where performance is not an issue, and RCU
provides a simpler implementation. An example of this situation
@@ -35,13 +34,13 @@ over a rather long period of time, but improvements are always welcome!
If you choose #b, be prepared to describe how you have handled
memory barriers on weakly ordered machines (pretty much all of
them -- even x86 allows reads to be reordered), and be prepared
to explain why this added complexity is worthwhile. If you
choose #c, be prepared to explain how this single task does not
become a major bottleneck on big multiprocessor machines (for
example, if the task is updating information relating to itself
that other tasks can read, there by definition can be no
bottleneck).
them -- even x86 allows later loads to be reordered to precede
earlier stores), and be prepared to explain why this added
complexity is worthwhile. If you choose #c, be prepared to
explain how this single task does not become a major bottleneck on
big multiprocessor machines (for example, if the task is updating
information relating to itself that other tasks can read, there
by definition can be no bottleneck).
2. Do the RCU read-side critical sections make proper use of
rcu_read_lock() and friends? These primitives are needed
@@ -51,8 +50,10 @@ over a rather long period of time, but improvements are always welcome!
actuarial risk of your kernel.
As a rough rule of thumb, any dereference of an RCU-protected
pointer must be covered by rcu_read_lock() or rcu_read_lock_bh()
or by the appropriate update-side lock.
pointer must be covered by rcu_read_lock(), rcu_read_lock_bh(),
rcu_read_lock_sched(), or by the appropriate update-side lock.
Disabling of preemption can serve as rcu_read_lock_sched(), but
is less readable.
3. Does the update code tolerate concurrent accesses?
@@ -62,25 +63,27 @@ over a rather long period of time, but improvements are always welcome!
of ways to handle this concurrency, depending on the situation:
a. Use the RCU variants of the list and hlist update
primitives to add, remove, and replace elements on an
RCU-protected list. Alternatively, use the RCU-protected
trees that have been added to the Linux kernel.
primitives to add, remove, and replace elements on
an RCU-protected list. Alternatively, use the other
RCU-protected data structures that have been added to
the Linux kernel.
This is almost always the best approach.
b. Proceed as in (a) above, but also maintain per-element
locks (that are acquired by both readers and writers)
that guard per-element state. Of course, fields that
the readers refrain from accessing can be guarded by the
update-side lock.
the readers refrain from accessing can be guarded by
some other lock acquired only by updaters, if desired.
This works quite well, also.
c. Make updates appear atomic to readers. For example,
pointer updates to properly aligned fields will appear
atomic, as will individual atomic primitives. Operations
performed under a lock and sequences of multiple atomic
primitives will -not- appear to be atomic.
pointer updates to properly aligned fields will
appear atomic, as will individual atomic primitives.
Sequences of perations performed under a lock will -not-
appear to be atomic to RCU readers, nor will sequences
of multiple atomic primitives.
This can work, but is starting to get a bit tricky.
@@ -98,9 +101,9 @@ over a rather long period of time, but improvements are always welcome!
a new structure containing updated values.
4. Weakly ordered CPUs pose special challenges. Almost all CPUs
are weakly ordered -- even i386 CPUs allow reads to be reordered.
RCU code must take all of the following measures to prevent
memory-corruption problems:
are weakly ordered -- even x86 CPUs allow later loads to be
reordered to precede earlier stores. RCU code must take all of
the following measures to prevent memory-corruption problems:
a. Readers must maintain proper ordering of their memory
accesses. The rcu_dereference() primitive ensures that
@@ -113,14 +116,25 @@ over a rather long period of time, but improvements are always welcome!
The rcu_dereference() primitive is also an excellent
documentation aid, letting the person reading the code
know exactly which pointers are protected by RCU.
Please note that compilers can also reorder code, and
they are becoming increasingly aggressive about doing
just that. The rcu_dereference() primitive therefore
also prevents destructive compiler optimizations.
The rcu_dereference() primitive is used by the various
"_rcu()" list-traversal primitives, such as the
list_for_each_entry_rcu(). Note that it is perfectly
legal (if redundant) for update-side code to use
rcu_dereference() and the "_rcu()" list-traversal
primitives. This is particularly useful in code
that is common to readers and updaters.
The rcu_dereference() primitive is used by the
various "_rcu()" list-traversal primitives, such
as the list_for_each_entry_rcu(). Note that it is
perfectly legal (if redundant) for update-side code to
use rcu_dereference() and the "_rcu()" list-traversal
primitives. This is particularly useful in code that
is common to readers and updaters. However, lockdep
will complain if you access rcu_dereference() outside
of an RCU read-side critical section. See lockdep.txt
to learn what to do about this.
Of course, neither rcu_dereference() nor the "_rcu()"
list-traversal primitives can substitute for a good
concurrency design coordinating among multiple updaters.
b. If the list macros are being used, the list_add_tail_rcu()
and list_add_rcu() primitives must be used in order
@@ -135,11 +149,14 @@ over a rather long period of time, but improvements are always welcome!
readers. Similarly, if the hlist macros are being used,
the hlist_del_rcu() primitive is required.
The list_replace_rcu() primitive may be used to
replace an old structure with a new one in an
RCU-protected list.
The list_replace_rcu() and hlist_replace_rcu() primitives
may be used to replace an old structure with a new one
in their respective types of RCU-protected lists.
d. Updates must ensure that initialization of a given
d. Rules similar to (4b) and (4c) apply to the "hlist_nulls"
type of RCU-protected linked lists.
e. Updates must ensure that initialization of a given
structure happens before pointers to that structure are
publicized. Use the rcu_assign_pointer() primitive
when publicizing a pointer to a structure that can
@@ -151,16 +168,31 @@ over a rather long period of time, but improvements are always welcome!
it cannot block.
6. Since synchronize_rcu() can block, it cannot be called from
any sort of irq context. Ditto for synchronize_sched() and
synchronize_srcu().
any sort of irq context. The same rule applies for
synchronize_rcu_bh(), synchronize_sched(), synchronize_srcu(),
synchronize_rcu_expedited(), synchronize_rcu_bh_expedited(),
synchronize_sched_expedite(), and synchronize_srcu_expedited().
7. If the updater uses call_rcu(), then the corresponding readers
must use rcu_read_lock() and rcu_read_unlock(). If the updater
uses call_rcu_bh(), then the corresponding readers must use
rcu_read_lock_bh() and rcu_read_unlock_bh(). If the updater
uses call_rcu_sched(), then the corresponding readers must
disable preemption. Mixing things up will result in confusion
and broken kernels.
The expedited forms of these primitives have the same semantics
as the non-expedited forms, but expediting is both expensive
and unfriendly to real-time workloads. Use of the expedited
primitives should be restricted to rare configuration-change
operations that would not normally be undertaken while a real-time
workload is running.
7. If the updater uses call_rcu() or synchronize_rcu(), then the
corresponding readers must use rcu_read_lock() and
rcu_read_unlock(). If the updater uses call_rcu_bh() or
synchronize_rcu_bh(), then the corresponding readers must
use rcu_read_lock_bh() and rcu_read_unlock_bh(). If the
updater uses call_rcu_sched() or synchronize_sched(), then
the corresponding readers must disable preemption, possibly
by calling rcu_read_lock_sched() and rcu_read_unlock_sched().
If the updater uses synchronize_srcu(), the the corresponding
readers must use srcu_read_lock() and srcu_read_unlock(),
and with the same srcu_struct. The rules for the expedited
primitives are the same as for their non-expedited counterparts.
Mixing things up will result in confusion and broken kernels.
One exception to this rule: rcu_read_lock() and rcu_read_unlock()
may be substituted for rcu_read_lock_bh() and rcu_read_unlock_bh()
@@ -212,6 +244,8 @@ over a rather long period of time, but improvements are always welcome!
e. Periodically invoke synchronize_rcu(), permitting a limited
number of updates per grace period.
The same cautions apply to call_rcu_bh() and call_rcu_sched().
9. All RCU list-traversal primitives, which include
rcu_dereference(), list_for_each_entry_rcu(),
list_for_each_continue_rcu(), and list_for_each_safe_rcu(),
@@ -219,7 +253,9 @@ over a rather long period of time, but improvements are always welcome!
must be protected by appropriate update-side locks. RCU
read-side critical sections are delimited by rcu_read_lock()
and rcu_read_unlock(), or by similar primitives such as
rcu_read_lock_bh() and rcu_read_unlock_bh().
rcu_read_lock_bh() and rcu_read_unlock_bh(), in which case
the matching rcu_dereference() primitive must be used in order
to keep lockdep happy, in this case, rcu_dereference_bh().
The reason that it is permissible to use RCU list-traversal
primitives when the update-side lock is held is that doing so
@@ -229,7 +265,8 @@ over a rather long period of time, but improvements are always welcome!
10. Conversely, if you are in an RCU read-side critical section,
and you don't hold the appropriate update-side lock, you -must-
use the "_rcu()" variants of the list macros. Failing to do so
will break Alpha and confuse people reading your code.
will break Alpha, cause aggressive compilers to generate bad code,
and confuse people trying to read your code.
11. Note that synchronize_rcu() -only- guarantees to wait until
all currently executing rcu_read_lock()-protected RCU read-side
@@ -239,15 +276,21 @@ over a rather long period of time, but improvements are always welcome!
rcu_read_lock()-protected read-side critical sections, do -not-
use synchronize_rcu().
If you want to wait for some of these other things, you might
instead need to use synchronize_irq() or synchronize_sched().
Similarly, disabling preemption is not an acceptable substitute
for rcu_read_lock(). Code that attempts to use preemption
disabling where it should be using rcu_read_lock() will break
in real-time kernel builds.
If you want to wait for interrupt handlers, NMI handlers, and
code under the influence of preempt_disable(), you instead
need to use synchronize_irq() or synchronize_sched().
12. Any lock acquired by an RCU callback must be acquired elsewhere
with softirq disabled, e.g., via spin_lock_irqsave(),
spin_lock_bh(), etc. Failing to disable irq on a given
acquisition of that lock will result in deadlock as soon as the
RCU callback happens to interrupt that acquisition's critical
section.
acquisition of that lock will result in deadlock as soon as
the RCU softirq handler happens to run your RCU callback while
interrupting that acquisition's critical section.
13. RCU callbacks can be and are executed in parallel. In many cases,
the callback code simply wrappers around kfree(), so that this
@@ -265,29 +308,30 @@ over a rather long period of time, but improvements are always welcome!
not the case, a self-spawning RCU callback would prevent the
victim CPU from ever going offline.)
14. SRCU (srcu_read_lock(), srcu_read_unlock(), and synchronize_srcu())
may only be invoked from process context. Unlike other forms of
RCU, it -is- permissible to block in an SRCU read-side critical
section (demarked by srcu_read_lock() and srcu_read_unlock()),
hence the "SRCU": "sleepable RCU". Please note that if you
don't need to sleep in read-side critical sections, you should
be using RCU rather than SRCU, because RCU is almost always
faster and easier to use than is SRCU.
14. SRCU (srcu_read_lock(), srcu_read_unlock(), srcu_dereference(),
synchronize_srcu(), and synchronize_srcu_expedited()) may only
be invoked from process context. Unlike other forms of RCU, it
-is- permissible to block in an SRCU read-side critical section
(demarked by srcu_read_lock() and srcu_read_unlock()), hence the
"SRCU": "sleepable RCU". Please note that if you don't need
to sleep in read-side critical sections, you should be using
RCU rather than SRCU, because RCU is almost always faster and
easier to use than is SRCU.
Also unlike other forms of RCU, explicit initialization
and cleanup is required via init_srcu_struct() and
cleanup_srcu_struct(). These are passed a "struct srcu_struct"
that defines the scope of a given SRCU domain. Once initialized,
the srcu_struct is passed to srcu_read_lock(), srcu_read_unlock()
and synchronize_srcu(). A given synchronize_srcu() waits only
for SRCU read-side critical sections governed by srcu_read_lock()
and srcu_read_unlock() calls that have been passd the same
srcu_struct. This property is what makes sleeping read-side
critical sections tolerable -- a given subsystem delays only
its own updates, not those of other subsystems using SRCU.
Therefore, SRCU is less prone to OOM the system than RCU would
be if RCU's read-side critical sections were permitted to
sleep.
synchronize_srcu(), and synchronize_srcu_expedited(). A given
synchronize_srcu() waits only for SRCU read-side critical
sections governed by srcu_read_lock() and srcu_read_unlock()
calls that have been passed the same srcu_struct. This property
is what makes sleeping read-side critical sections tolerable --
a given subsystem delays only its own updates, not those of other
subsystems using SRCU. Therefore, SRCU is less prone to OOM the
system than RCU would be if RCU's read-side critical sections
were permitted to sleep.
The ability to sleep in read-side critical sections does not
come for free. First, corresponding srcu_read_lock() and
@@ -311,12 +355,12 @@ over a rather long period of time, but improvements are always welcome!
destructive operation, and -only- -then- invoke call_rcu(),
synchronize_rcu(), or friends.
Because these primitives only wait for pre-existing readers,
it is the caller's responsibility to guarantee safety to
any subsequent readers.
Because these primitives only wait for pre-existing readers, it
is the caller's responsibility to guarantee that any subsequent
readers will execute safely.
16. The various RCU read-side primitives do -not- contain memory
barriers. The CPU (and in some cases, the compiler) is free
to reorder code into and out of RCU read-side critical sections.
It is the responsibility of the RCU update-side primitives to
deal with this.
16. The various RCU read-side primitives do -not- necessarily contain
memory barriers. You should therefore plan for the CPU
and the compiler to freely reorder code into and out of RCU
read-side critical sections. It is the responsibility of the
RCU update-side primitives to deal with this.

67
Documentation/RCU/lockdep.txt Normal file
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@@ -0,0 +1,67 @@
RCU and lockdep checking
All flavors of RCU have lockdep checking available, so that lockdep is
aware of when each task enters and leaves any flavor of RCU read-side
critical section. Each flavor of RCU is tracked separately (but note
that this is not the case in 2.6.32 and earlier). This allows lockdep's
tracking to include RCU state, which can sometimes help when debugging
deadlocks and the like.
In addition, RCU provides the following primitives that check lockdep's
state:
rcu_read_lock_held() for normal RCU.
rcu_read_lock_bh_held() for RCU-bh.
rcu_read_lock_sched_held() for RCU-sched.
srcu_read_lock_held() for SRCU.
These functions are conservative, and will therefore return 1 if they
aren't certain (for example, if CONFIG_DEBUG_LOCK_ALLOC is not set).
This prevents things like WARN_ON(!rcu_read_lock_held()) from giving false
positives when lockdep is disabled.
In addition, a separate kernel config parameter CONFIG_PROVE_RCU enables
checking of rcu_dereference() primitives:
rcu_dereference(p):
Check for RCU read-side critical section.
rcu_dereference_bh(p):
Check for RCU-bh read-side critical section.
rcu_dereference_sched(p):
Check for RCU-sched read-side critical section.
srcu_dereference(p, sp):
Check for SRCU read-side critical section.
rcu_dereference_check(p, c):
Use explicit check expression "c".
rcu_dereference_raw(p)
Don't check. (Use sparingly, if at all.)
The rcu_dereference_check() check expression can be any boolean
expression, but would normally include one of the rcu_read_lock_held()
family of functions and a lockdep expression. However, any boolean
expression can be used. For a moderately ornate example, consider
the following:
file = rcu_dereference_check(fdt->fd[fd],
rcu_read_lock_held() ||
lockdep_is_held(&files->file_lock) ||
atomic_read(&files->count) == 1);
This expression picks up the pointer "fdt->fd[fd]" in an RCU-safe manner,
and, if CONFIG_PROVE_RCU is configured, verifies that this expression
is used in:
1. An RCU read-side critical section, or
2. with files->file_lock held, or
3. on an unshared files_struct.
In case (1), the pointer is picked up in an RCU-safe manner for vanilla
RCU read-side critical sections, in case (2) the ->file_lock prevents
any change from taking place, and finally, in case (3) the current task
is the only task accessing the file_struct, again preventing any change
from taking place.
There are currently only "universal" versions of the rcu_assign_pointer()
and RCU list-/tree-traversal primitives, which do not (yet) check for
being in an RCU read-side critical section. In the future, separate
versions of these primitives might be created.

48
Documentation/RCU/rcu.txt
View File

@@ -75,6 +75,8 @@ o I hear that RCU is patented? What is with that?
search for the string "Patent" in RTFP.txt to find them.
Of these, one was allowed to lapse by the assignee, and the
others have been contributed to the Linux kernel under GPL.
There are now also LGPL implementations of user-level RCU
available (http://lttng.org/?q=node/18).
o I hear that RCU needs work in order to support realtime kernels?
@@ -91,48 +93,4 @@ o Where can I find more information on RCU?
o What are all these files in this directory?
NMI-RCU.txt
Describes how to use RCU to implement dynamic
NMI handlers, which can be revectored on the fly,
without rebooting.
RTFP.txt
List of RCU-related publications and web sites.
UP.txt
Discussion of RCU usage in UP kernels.
arrayRCU.txt
Describes how to use RCU to protect arrays, with
resizeable arrays whose elements reference other
data structures being of the most interest.
checklist.txt
Lists things to check for when inspecting code that
uses RCU.
listRCU.txt
Describes how to use RCU to protect linked lists.
This is the simplest and most common use of RCU
in the Linux kernel.
rcu.txt
You are reading it!
rcuref.txt
Describes how to combine use of reference counts
with RCU.
whatisRCU.txt
Overview of how the RCU implementation works. Along
the way, presents a conceptual view of RCU.
See 00-INDEX for the list.

58
Documentation/RCU/stallwarn.txt Normal file
View File

@@ -0,0 +1,58 @@
Using RCU's CPU Stall Detector
The CONFIG_RCU_CPU_STALL_DETECTOR kernel config parameter enables
RCU's CPU stall detector, which detects conditions that unduly delay
RCU grace periods. The stall detector's idea of what constitutes
"unduly delayed" is controlled by a pair of C preprocessor macros:
RCU_SECONDS_TILL_STALL_CHECK
This macro defines the period of time that RCU will wait from
the beginning of a grace period until it issues an RCU CPU
stall warning. It is normally ten seconds.
RCU_SECONDS_TILL_STALL_RECHECK
This macro defines the period of time that RCU will wait after
issuing a stall warning until it issues another stall warning.
It is normally set to thirty seconds.
RCU_STALL_RAT_DELAY
The CPU stall detector tries to make the offending CPU rat on itself,
as this often gives better-quality stack traces. However, if
the offending CPU does not detect its own stall in the number
of jiffies specified by RCU_STALL_RAT_DELAY, then other CPUs will
complain. This is normally set to two jiffies.
The following problems can result in an RCU CPU stall warning:
o A CPU looping in an RCU read-side critical section.
o A CPU looping with interrupts disabled.
o A CPU looping with preemption disabled.
o For !CONFIG_PREEMPT kernels, a CPU looping anywhere in the kernel
without invoking schedule().
o A bug in the RCU implementation.
o A hardware failure. This is quite unlikely, but has occurred
at least once in a former life. A CPU failed in a running system,
becoming unresponsive, but not causing an immediate crash.
This resulted in a series of RCU CPU stall warnings, eventually
leading the realization that the CPU had failed.
The RCU, RCU-sched, and RCU-bh implementations have CPU stall warning.
SRCU does not do so directly, but its calls to synchronize_sched() will
result in RCU-sched detecting any CPU stalls that might be occurring.
To diagnose the cause of the stall, inspect the stack traces. The offending
function will usually be near the top of the stack. If you have a series
of stall warnings from a single extended stall, comparing the stack traces
can often help determine where the stall is occurring, which will usually
be in the function nearest the top of the stack that stays the same from
trace to trace.
RCU bugs can often be debugged with the help of CONFIG_RCU_TRACE.

12
Documentation/RCU/torture.txt
View File

@@ -30,6 +30,18 @@ MODULE PARAMETERS
This module has the following parameters:
fqs_duration Duration (in microseconds) of artificially induced bursts
of force_quiescent_state() invocations. In RCU
implementations having force_quiescent_state(), these
bursts help force races between forcing a given grace
period and that grace period ending on its own.
fqs_holdoff Holdoff time (in microseconds) between consecutive calls
to force_quiescent_state() within a burst.
fqs_stutter Wait time (in seconds) between consecutive bursts
of calls to force_quiescent_state().
irqreaders Says to invoke RCU readers from irq level. This is currently
done via timers. Defaults to "1" for variants of RCU that
permit this. (Or, more accurately, variants of RCU that do

16
Documentation/RCU/whatisRCU.txt
View File

@@ -323,14 +323,17 @@ used as follows:
Defer Protect
a. synchronize_rcu() rcu_read_lock() / rcu_read_unlock()
call_rcu()
call_rcu() rcu_dereference()
b. call_rcu_bh() rcu_read_lock_bh() / rcu_read_unlock_bh()
rcu_dereference_bh()
c. synchronize_sched() preempt_disable() / preempt_enable()
c. synchronize_sched() rcu_read_lock_sched() / rcu_read_unlock_sched()
preempt_disable() / preempt_enable()
local_irq_save() / local_irq_restore()
hardirq enter / hardirq exit
NMI enter / NMI exit
rcu_dereference_sched()
These three mechanisms are used as follows:
@@ -780,9 +783,8 @@ Linux-kernel source code, but it helps to have a full list of the
APIs, since there does not appear to be a way to categorize them
in docbook. Here is the list, by category.
RCU pointer/list traversal:
RCU list traversal:
rcu_dereference
list_for_each_entry_rcu
hlist_for_each_entry_rcu
hlist_nulls_for_each_entry_rcu
@@ -808,7 +810,7 @@ RCU: Critical sections Grace period Barrier
rcu_read_lock synchronize_net rcu_barrier
rcu_read_unlock synchronize_rcu
synchronize_rcu_expedited
rcu_dereference synchronize_rcu_expedited
call_rcu
@@ -816,7 +818,7 @@ bh: Critical sections Grace period Barrier
rcu_read_lock_bh call_rcu_bh rcu_barrier_bh
rcu_read_unlock_bh synchronize_rcu_bh
synchronize_rcu_bh_expedited
rcu_dereference_bh synchronize_rcu_bh_expedited
sched: Critical sections Grace period Barrier
@@ -825,12 +827,14 @@ sched: Critical sections Grace period Barrier
rcu_read_unlock_sched call_rcu_sched
[preempt_disable] synchronize_sched_expedited
[and friends]
rcu_dereference_sched
SRCU: Critical sections Grace period Barrier
srcu_read_lock synchronize_srcu N/A
srcu_read_unlock synchronize_srcu_expedited
srcu_dereference
SRCU: Initialization/cleanup
init_srcu_struct

5
Documentation/SubmitChecklist
View File

@@ -15,7 +15,7 @@ kernel patches.
2: Passes allnoconfig, allmodconfig
3: Builds on multiple CPU architectures by using local cross-compile tools
or something like PLM at OSDL.
or some other build farm.
4: ppc64 is a good architecture for cross-compilation checking because it
tends to use `unsigned long' for 64-bit quantities.
@@ -88,3 +88,6 @@ kernel patches.
24: All memory barriers {e.g., barrier(), rmb(), wmb()} need a comment in the
source code that explains the logic of what they are doing and why.
25: If any ioctl's are added by the patch, then also update
Documentation/ioctl/ioctl-number.txt.

66
Documentation/acpi/method-customizing.txt Normal file
View File

@@ -0,0 +1,66 @@
Linux ACPI Custom Control Method How To
=======================================
Written by Zhang Rui <rui.zhang@intel.com>
Linux supports customizing ACPI control methods at runtime.
Users can use this to
1. override an existing method which may not work correctly,
or just for debugging purposes.
2. insert a completely new method in order to create a missing
method such as _OFF, _ON, _STA, _INI, etc.
For these cases, it is far simpler to dynamically install a single
control method rather than override the entire DSDT, because kernel
rebuild/reboot is not needed and test result can be got in minutes.
Note: Only ACPI METHOD can be overridden, any other object types like
"Device", "OperationRegion", are not recognized.
Note: The same ACPI control method can be overridden for many times,
and it's always the latest one that used by Linux/kernel.
1. override an existing method
a) get the ACPI table via ACPI sysfs I/F. e.g. to get the DSDT,
just run "cat /sys/firmware/acpi/tables/DSDT > /tmp/dsdt.dat"
b) disassemble the table by running "iasl -d dsdt.dat".
c) rewrite the ASL code of the method and save it in a new file,
d) package the new file (psr.asl) to an ACPI table format.
Here is an example of a customized \_SB._AC._PSR method,
DefinitionBlock ("", "SSDT", 1, "", "", 0x20080715)
{
External (ACON)
Method (\_SB_.AC._PSR, 0, NotSerialized)
{
Store ("In AC _PSR", Debug)
Return (ACON)
}
}
Note that the full pathname of the method in ACPI namespace
should be used.
And remember to use "External" to declare external objects.
e) assemble the file to generate the AML code of the method.
e.g. "iasl psr.asl" (psr.aml is generated as a result)
f) mount debugfs by "mount -t debugfs none /sys/kernel/debug"
g) override the old method via the debugfs by running
"cat /tmp/psr.aml > /sys/kernel/debug/acpi/custom_method"
2. insert a new method
This is easier than overriding an existing method.
We just need to create the ASL code of the method we want to
insert and then follow the step c) ~ g) in section 1.
3. undo your changes
The "undo" operation is not supported for a new inserted method
right now, i.e. we can not remove a method currently.
For an overrided method, in order to undo your changes, please
save a copy of the method original ASL code in step c) section 1,
and redo step c) ~ g) to override the method with the original one.
Note: We can use a kernel with multiple custom ACPI method running,
But each individual write to debugfs can implement a SINGLE
method override. i.e. if we want to insert/override multiple
ACPI methods, we need to redo step c) ~ g) for multiple times.

6
Documentation/arm/memory.txt
View File

@@ -59,7 +59,11 @@ PAGE_OFFSET high_memory-1 Kernel direct-mapped RAM region.
This maps the platforms RAM, and typically
maps all platform RAM in a 1:1 relationship.
TASK_SIZE PAGE_OFFSET-1 Kernel module space
PKMAP_BASE PAGE_OFFSET-1 Permanent kernel mappings
One way of mapping HIGHMEM pages into kernel
space.
MODULES_VADDR MODULES_END-1 Kernel module space
Kernel modules inserted via insmod are
placed here using dynamic mappings.

3
Documentation/blackfin/00-INDEX
View File

@@ -1,9 +1,6 @@
00-INDEX
- This file
cache-lock.txt
- HOWTO for blackfin cache locking.
cachefeatures.txt
- Supported cache features.

6
Documentation/blackfin/Makefile Normal file
View File

@@ -0,0 +1,6 @@
obj-m := gptimers-example.o
all: modules
modules clean:
$(MAKE) -C ../.. SUBDIRS=$(PWD) $@

48
Documentation/blackfin/cache-lock.txt
View File

@@ -1,48 +0,0 @@
/*
* File: Documentation/blackfin/cache-lock.txt
* Based on:
* Author:
*
* Created:
* Description: This file contains the simple DMA Implementation for Blackfin
*
* Rev: $Id: cache-lock.txt 2384 2006-11-01 04:12:43Z magicyang $
*
* Modified:
* Copyright 2004-2006 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
*/
How to lock your code in cache in uClinux/blackfin
--------------------------------------------------
There are only a few steps required to lock your code into the cache.
Currently you can lock the code by Way.
Below are the interface provided for locking the cache.
1. cache_grab_lock(int Ways);
This function grab the lock for locking your code into the cache specified
by Ways.
2. cache_lock(int Ways);
This function should be called after your critical code has been executed.
Once the critical code exits, the code is now loaded into the cache. This
function locks the code into the cache.
So, the example sequence will be:
cache_grab_lock(WAY0_L); /* Grab the lock */
critical_code(); /* Execute the code of interest */
cache_lock(WAY0_L); /* Lock the cache */
Where WAY0_L signifies WAY0 locking.

10
Documentation/blackfin/cachefeatures.txt
View File

@@ -41,16 +41,6 @@
icplb_flush();
dcplb_flush();
- Locking the cache.
cache_grab_lock();
cache_lock();
Please refer linux-2.6.x/Documentation/blackfin/cache-lock.txt for how to
lock the cache.
Locking the cache is optional feature.
- Miscellaneous cache functions.
flush_cache_all();

83
Documentation/blackfin/gptimers-example.c Normal file
View File

@@ -0,0 +1,83 @@
/*
* Simple gptimers example
* http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:drivers:gptimers
*
* Copyright 2007-2009 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <linux/interrupt.h>
#include <linux/module.h>
#include <asm/gptimers.h>
#include <asm/portmux.h>
/* ... random driver includes ... */
#define DRIVER_NAME "gptimer_example"
struct gptimer_data {
uint32_t period, width;
};
static struct gptimer_data data;
/* ... random driver state ... */
static irqreturn_t gptimer_example_irq(int irq, void *dev_id)
{
struct gptimer_data *data = dev_id;
/* make sure it was our timer which caused the interrupt */
if (!get_gptimer_intr(TIMER5_id))
return IRQ_NONE;
/* read the width/period values that were captured for the waveform */
data->width = get_gptimer_pwidth(TIMER5_id);
data->period = get_gptimer_period(TIMER5_id);
/* acknowledge the interrupt */
clear_gptimer_intr(TIMER5_id);
/* tell the upper layers we took care of things */
return IRQ_HANDLED;
}
/* ... random driver code ... */
static int __init gptimer_example_init(void)
{
int ret;
/* grab the peripheral pins */
ret = peripheral_request(P_TMR5, DRIVER_NAME);
if (ret) {
printk(KERN_NOTICE DRIVER_NAME ": peripheral request failed\n");
return ret;
}
/* grab the IRQ for the timer */
ret = request_irq(IRQ_TIMER5, gptimer_example_irq, IRQF_SHARED, DRIVER_NAME, &data);
if (ret) {
printk(KERN_NOTICE DRIVER_NAME ": IRQ request failed\n");
peripheral_free(P_TMR5);
return ret;
}
/* setup the timer and enable it */
set_gptimer_config(TIMER5_id, WDTH_CAP | PULSE_HI | PERIOD_CNT | IRQ_ENA);
enable_gptimers(TIMER5bit);
return 0;
}
module_init(gptimer_example_init);
static void __exit gptimer_example_exit(void)
{
disable_gptimers(TIMER5bit);
free_irq(IRQ_TIMER5, &data);
peripheral_free(P_TMR5);
}
module_exit(gptimer_example_exit);
MODULE_LICENSE("BSD");

2
Documentation/block/00-INDEX
View File

@@ -1,7 +1,5 @@
00-INDEX
- This file
as-iosched.txt
- Anticipatory IO scheduler
barrier.txt
- I/O Barriers
biodoc.txt

172
Documentation/block/as-iosched.txt
View File

@@ -1,172 +0,0 @@
Anticipatory IO scheduler
-------------------------
Nick Piggin <piggin@cyberone.com.au> 13 Sep 2003
Attention! Database servers, especially those using "TCQ" disks should
investigate performance with the 'deadline' IO scheduler. Any system with high
disk performance requirements should do so, in fact.
If you see unusual performance characteristics of your disk systems, or you
see big performance regressions versus the deadline scheduler, please email
me. Database users don't bother unless you're willing to test a lot of patches
from me ;) its a known issue.
Also, users with hardware RAID controllers, doing striping, may find
highly variable performance results with using the as-iosched. The
as-iosched anticipatory implementation is based on the notion that a disk
device has only one physical seeking head. A striped RAID controller
actually has a head for each physical device in the logical RAID device.
However, setting the antic_expire (see tunable parameters below) produces
very similar behavior to the deadline IO scheduler.
Selecting IO schedulers
-----------------------
Refer to Documentation/block/switching-sched.txt for information on
selecting an io scheduler on a per-device basis.
Anticipatory IO scheduler Policies
----------------------------------
The as-iosched implementation implements several layers of policies
to determine when an IO request is dispatched to the disk controller.
Here are the policies outlined, in order of application.
1. one-way Elevator algorithm.
The elevator algorithm is similar to that used in deadline scheduler, with
the addition that it allows limited backward movement of the elevator
(i.e. seeks backwards). A seek backwards can occur when choosing between
two IO requests where one is behind the elevator's current position, and
the other is in front of the elevator's position. If the seek distance to
the request in back of the elevator is less than half the seek distance to
the request in front of the elevator, then the request in back can be chosen.
Backward seeks are also limited to a maximum of MAXBACK (1024*1024) sectors.
This favors forward movement of the elevator, while allowing opportunistic
"short" backward seeks.
2. FIFO expiration times for reads and for writes.
This is again very similar to the deadline IO scheduler. The expiration
times for requests on these lists is tunable using the parameters read_expire
and write_expire discussed below. When a read or a write expires in this way,
the IO scheduler will interrupt its current elevator sweep or read anticipation
to service the expired request.
3. Read and write request batching
A batch is a collection of read requests or a collection of write
requests. The as scheduler alternates dispatching read and write batches
to the driver. In the case a read batch, the scheduler submits read
requests to the driver as long as there are read requests to submit, and
the read batch time limit has not been exceeded (read_batch_expire).
The read batch time limit begins counting down only when there are
competing write requests pending.
In the case of a write batch, the scheduler submits write requests to
the driver as long as there are write requests available, and the
write batch time limit has not been exceeded (write_batch_expire).
However, the length of write batches will be gradually shortened
when read batches frequently exceed their time limit.
When changing between batch types, the scheduler waits for all requests
from the previous batch to complete before scheduling requests for the
next batch.
The read and write fifo expiration times described in policy 2 above
are checked only when in scheduling IO of a batch for the corresponding
(read/write) type. So for example, the read FIFO timeout values are
tested only during read batches. Likewise, the write FIFO timeout
values are tested only during write batches. For this reason,
it is generally not recommended for the read batch time
to be longer than the write expiration time, nor for the write batch
time to exceed the read expiration time (see tunable parameters below).
When the IO scheduler changes from a read to a write batch,
it begins the elevator from the request that is on the head of the
write expiration FIFO. Likewise, when changing from a write batch to
a read batch, scheduler begins the elevator from the first entry
on the read expiration FIFO.
4. Read anticipation.
Read anticipation occurs only when scheduling a read batch.
This implementation of read anticipation allows only one read request
to be dispatched to the disk controller at a time. In
contrast, many write requests may be dispatched to the disk controller
at a time during a write batch. It is this characteristic that can make
the anticipatory scheduler perform anomalously with controllers supporting
TCQ, or with hardware striped RAID devices. Setting the antic_expire
queue parameter (see below) to zero disables this behavior, and the
anticipatory scheduler behaves essentially like the deadline scheduler.
When read anticipation is enabled (antic_expire is not zero), reads
are dispatched to the disk controller one at a time.
At the end of each read request, the IO scheduler examines its next
candidate read request from its sorted read list. If that next request
is from the same process as the request that just completed,
or if the next request in the queue is "very close" to the
just completed request, it is dispatched immediately. Otherwise,
statistics (average think time, average seek distance) on the process
that submitted the just completed request are examined. If it seems
likely that that process will submit another request soon, and that
request is likely to be near the just completed request, then the IO
scheduler will stop dispatching more read requests for up to (antic_expire)
milliseconds, hoping that process will submit a new request near the one
that just completed. If such a request is made, then it is dispatched
immediately. If the antic_expire wait time expires, then the IO scheduler
will dispatch the next read request from the sorted read queue.
To decide whether an anticipatory wait is worthwhile, the scheduler
maintains statistics for each process that can be used to compute
mean "think time" (the time between read requests), and mean seek
distance for that process. One observation is that these statistics
are associated with each process, but those statistics are not associated
with a specific IO device. So for example, if a process is doing IO
on several file systems on separate devices, the statistics will be
a combination of IO behavior from all those devices.
Tuning the anticipatory IO scheduler
------------------------------------
When using 'as', the anticipatory IO scheduler there are 5 parameters under
/sys/block/*/queue/iosched/. All are units of milliseconds.
The parameters are:
* read_expire
Controls how long until a read request becomes "expired". It also controls the
interval between which expired requests are served, so set to 50, a request
might take anywhere < 100ms to be serviced _if_ it is the next on the
expired list. Obviously request expiration strategies won't make the disk
go faster. The result basically equates to the timeslice a single reader
gets in the presence of other IO. 100*((seek time / read_expire) + 1) is
very roughly the % streaming read efficiency your disk should get with
multiple readers.
* read_batch_expire
Controls how much time a batch of reads is given before pending writes are
served. A higher value is more efficient. This might be set below read_expire
if writes are to be given higher priority than reads, but reads are to be
as efficient as possible when there are no writes. Generally though, it
should be some multiple of read_expire.
* write_expire, and
* write_batch_expire are equivalent to the above, for writes.
* antic_expire
Controls the maximum amount of time we can anticipate a good read (one
with a short seek distance from the most recently completed request) before
giving up. Many other factors may cause anticipation to be stopped early,
or some processes will not be "anticipated" at all. Should be a bit higher
for big seek time devices though not a linear correspondence - most
processes have only a few ms thinktime.
In addition to the tunables above there is a read-only file named est_time
which, when read, will show:
- The probability of a task exiting without a cooperating task
submitting an anticipated IO.
- The current mean think time.
- The seek distance used to determine if an incoming IO is better.

2
Documentation/block/biodoc.txt
View File

@@ -186,7 +186,7 @@ a virtual address mapping (unlike the earlier scheme of virtual address
do not have a corresponding kernel virtual address space mapping) and
low-memory pages.
Note: Please refer to Documentation/DMA-mapping.txt for a discussion
Note: Please refer to Documentation/PCI/PCI-DMA-mapping.txt for a discussion
on PCI high mem DMA aspects and mapping of scatter gather lists, and support
for 64 bit PCI.

10
Documentation/block/queue-sysfs.txt
View File

@@ -25,11 +25,11 @@ size allowed by the hardware.
nomerges (RW)
-------------
This enables the user to disable the lookup logic involved with IO merging
requests in the block layer. Merging may still occur through a direct
1-hit cache, since that comes for (almost) free. The IO scheduler will not
waste cycles doing tree/hash lookups for merges if nomerges is 1. Defaults
to 0, enabling all merges.
This enables the user to disable the lookup logic involved with IO
merging requests in the block layer. By default (0) all merges are
enabled. When set to 1 only simple one-hit merges will be tried. When
set to 2 no merge algorithms will be tried (including one-hit or more
complex tree/hash lookups).
nr_requests (RW)
----------------

30
Documentation/cachetlb.txt
View File

@@ -88,12 +88,12 @@ changes occur:
This is used primarily during fault processing.
5) void update_mmu_cache(struct vm_area_struct *vma,
unsigned long address, pte_t pte)
unsigned long address, pte_t *ptep)
At the end of every page fault, this routine is invoked to
tell the architecture specific code that a translation
described by "pte" now exists at virtual address "address"
for address space "vma->vm_mm", in the software page tables.
now exists at virtual address "address" for address space
"vma->vm_mm", in the software page tables.
A port may use this information in any way it so chooses.
For example, it could use this event to pre-load TLB
@@ -377,3 +377,27 @@ maps this page at its virtual address.
All the functionality of flush_icache_page can be implemented in
flush_dcache_page and update_mmu_cache. In 2.7 the hope is to
remove this interface completely.
The final category of APIs is for I/O to deliberately aliased address
ranges inside the kernel. Such aliases are set up by use of the
vmap/vmalloc API. Since kernel I/O goes via physical pages, the I/O
subsystem assumes that the user mapping and kernel offset mapping are
the only aliases. This isn't true for vmap aliases, so anything in
the kernel trying to do I/O to vmap areas must manually manage
coherency. It must do this by flushing the vmap range before doing
I/O and invalidating it after the I/O returns.
void flush_kernel_vmap_range(void *vaddr, int size)
flushes the kernel cache for a given virtual address range in
the vmap area. This is to make sure that any data the kernel
modified in the vmap range is made visible to the physical
page. The design is to make this area safe to perform I/O on.
Note that this API does *not* also flush the offset map alias
of the area.
void invalidate_kernel_vmap_range(void *vaddr, int size) invalidates
the cache for a given virtual address range in the vmap area
which prevents the processor from making the cache stale by
speculatively reading data while the I/O was occurring to the
physical pages. This is only necessary for data reads into the
vmap area.

39
Documentation/cdrom/ide-cd
View File

@@ -159,42 +159,7 @@ two arguments: the CDROM device, and the slot number to which you wish
to change. If the slot number is -1, the drive is unloaded.
4. Compilation options
----------------------
There are a few additional options which can be set when compiling the
driver. Most people should not need to mess with any of these; they
are listed here simply for completeness. A compilation option can be
enabled by adding a line of the form `#define <option> 1' to the top
of ide-cd.c. All these options are disabled by default.
VERBOSE_IDE_CD_ERRORS
If this is set, ATAPI error codes will be translated into textual
descriptions. In addition, a dump is made of the command which
provoked the error. This is off by default to save the memory used
by the (somewhat long) table of error descriptions.
STANDARD_ATAPI
If this is set, the code needed to deal with certain drives which do
not properly implement the ATAPI spec will be disabled. If you know
your drive implements ATAPI properly, you can turn this on to get a
slightly smaller kernel.
NO_DOOR_LOCKING
If this is set, the driver will never attempt to lock the door of
the drive.
CDROM_NBLOCKS_BUFFER
This sets the size of the buffer to be used for a CDROMREADAUDIO
ioctl. The default is 8.
TEST
This currently enables an additional ioctl which enables a user-mode
program to execute an arbitrary packet command. See the source for
details. This should be left off unless you know what you're doing.
5. Common problems
4. Common problems
------------------
This section discusses some common problems encountered when trying to
@@ -371,7 +336,7 @@ f. Data corruption.
expense of low system performance.
6. cdchange.c
5. cdchange.c
-------------
/*

4
Documentation/cpu-freq/governors.txt
View File

@@ -145,8 +145,8 @@ show_sampling_rate_max: THIS INTERFACE IS DEPRECATED, DON'T USE IT.
up_threshold: defines what the average CPU usage between the samplings
of 'sampling_rate' needs to be for the kernel to make a decision on
whether it should increase the frequency. For example when it is set
to its default value of '80' it means that between the checking
intervals the CPU needs to be on average more than 80% in use to then
to its default value of '95' it means that between the checking
intervals the CPU needs to be on average more than 95% in use to then
decide that the CPU frequency needs to be increased.
ignore_nice_load: this parameter takes a value of '0' or '1'. When

207
Documentation/cpu-freq/pcc-cpufreq.txt Normal file
View File

@@ -0,0 +1,207 @@
/*
* pcc-cpufreq.txt - PCC interface documentation
*
* Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
* Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
* INFRINGEMENT. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
Processor Clocking Control Driver
---------------------------------
Contents:
---------
1. Introduction
1.1 PCC interface
1.1.1 Get Average Frequency
1.1.2 Set Desired Frequency
1.2 Platforms affected
2. Driver and /sys details
2.1 scaling_available_frequencies
2.2 cpuinfo_transition_latency
2.3 cpuinfo_cur_freq
2.4 related_cpus
3. Caveats
1. Introduction:
----------------
Processor Clocking Control (PCC) is an interface between the platform
firmware and OSPM. It is a mechanism for coordinating processor
performance (ie: frequency) between the platform firmware and the OS.
The PCC driver (pcc-cpufreq) allows OSPM to take advantage of the PCC
interface.
OS utilizes the PCC interface to inform platform firmware what frequency the
OS wants for a logical processor. The platform firmware attempts to achieve
the requested frequency. If the request for the target frequency could not be
satisfied by platform firmware, then it usually means that power budget
conditions are in place, and "power capping" is taking place.
1.1 PCC interface:
------------------
The complete PCC specification is available here:
http://www.acpica.org/download/Processor-Clocking-Control-v1p0.pdf
PCC relies on a shared memory region that provides a channel for communication
between the OS and platform firmware. PCC also implements a "doorbell" that
is used by the OS to inform the platform firmware that a command has been
sent.
The ACPI PCCH() method is used to discover the location of the PCC shared
memory region. The shared memory region header contains the "command" and
"status" interface. PCCH() also contains details on how to access the platform
doorbell.
The following commands are supported by the PCC interface:
* Get Average Frequency
* Set Desired Frequency
The ACPI PCCP() method is implemented for each logical processor and is
used to discover the offsets for the input and output buffers in the shared
memory region.
When PCC mode is enabled, the platform will not expose processor performance
or throttle states (_PSS, _TSS and related ACPI objects) to OSPM. Therefore,
the native P-state driver (such as acpi-cpufreq for Intel, powernow-k8 for
AMD) will not load.
However, OSPM remains in control of policy. The governor (eg: "ondemand")
computes the required performance for each processor based on server workload.
The PCC driver fills in the command interface, and the input buffer and
communicates the request to the platform firmware. The platform firmware is
responsible for delivering the requested performance.
Each PCC command is "global" in scope and can affect all the logical CPUs in
the system. Therefore, PCC is capable of performing "group" updates. With PCC
the OS is capable of getting/setting the frequency of all the logical CPUs in
the system with a single call to the BIOS.
1.1.1 Get Average Frequency:
----------------------------
This command is used by the OSPM to query the running frequency of the
processor since the last time this command was completed. The output buffer
indicates the average unhalted frequency of the logical processor expressed as
a percentage of the nominal (ie: maximum) CPU frequency. The output buffer
also signifies if the CPU frequency is limited by a power budget condition.
1.1.2 Set Desired Frequency:
----------------------------
This command is used by the OSPM to communicate to the platform firmware the
desired frequency for a logical processor. The output buffer is currently
ignored by OSPM. The next invocation of "Get Average Frequency" will inform
OSPM if the desired frequency was achieved or not.
1.2 Platforms affected:
-----------------------
The PCC driver will load on any system where the platform firmware:
* supports the PCC interface, and the associated PCCH() and PCCP() methods
* assumes responsibility for managing the hardware clocking controls in order
to deliver the requested processor performance
Currently, certain HP ProLiant platforms implement the PCC interface. On those
platforms PCC is the "default" choice.
However, it is possible to disable this interface via a BIOS setting. In
such an instance, as is also the case on platforms where the PCC interface
is not implemented, the PCC driver will fail to load silently.
2. Driver and /sys details:
---------------------------
When the driver loads, it merely prints the lowest and the highest CPU
frequencies supported by the platform firmware.
The PCC driver loads with a message such as:
pcc-cpufreq: (v1.00.00) driver loaded with frequency limits: 1600 MHz, 2933
MHz
This means that the OPSM can request the CPU to run at any frequency in
between the limits (1600 MHz, and 2933 MHz) specified in the message.
Internally, there is no need for the driver to convert the "target" frequency
to a corresponding P-state.
The VERSION number for the driver will be of the format v.xy.ab.
eg: 1.00.02
----- --
| |
| -- this will increase with bug fixes/enhancements to the driver
|-- this is the version of the PCC specification the driver adheres to
The following is a brief discussion on some of the fields exported via the
/sys filesystem and how their values are affected by the PCC driver:
2.1 scaling_available_frequencies:
----------------------------------
scaling_available_frequencies is not created in /sys. No intermediate
frequencies need to be listed because the BIOS will try to achieve any
frequency, within limits, requested by the governor. A frequency does not have
to be strictly associated with a P-state.
2.2 cpuinfo_transition_latency:
-------------------------------
The cpuinfo_transition_latency field is 0. The PCC specification does
not include a field to expose this value currently.
2.3 cpuinfo_cur_freq:
---------------------
A) Often cpuinfo_cur_freq will show a value different than what is declared
in the scaling_available_frequencies or scaling_cur_freq, or scaling_max_freq.
This is due to "turbo boost" available on recent Intel processors. If certain
conditions are met the BIOS can achieve a slightly higher speed than requested
by OSPM. An example:
scaling_cur_freq : 2933000
cpuinfo_cur_freq : 3196000
B) There is a round-off error associated with the cpuinfo_cur_freq value.
Since the driver obtains the current frequency as a "percentage" (%) of the
nominal frequency from the BIOS, sometimes, the values displayed by
scaling_cur_freq and cpuinfo_cur_freq may not match. An example:
scaling_cur_freq : 1600000
cpuinfo_cur_freq : 1583000
In this example, the nominal frequency is 2933 MHz. The driver obtains the
current frequency, cpuinfo_cur_freq, as 54% of the nominal frequency:
54% of 2933 MHz = 1583 MHz
Nominal frequency is the maximum frequency of the processor, and it usually
corresponds to the frequency of the P0 P-state.
2.4 related_cpus:
-----------------
The related_cpus field is identical to affected_cpus.
affected_cpus : 4
related_cpus : 4
Currently, the PCC driver does not evaluate _PSD. The platforms that support
PCC do not implement SW_ALL. So OSPM doesn't need to perform any coordination
to ensure that the same frequency is requested of all dependent CPUs.
3. Caveats:
-----------
The "cpufreq_stats" module in its present form cannot be loaded and
expected to work with the PCC driver. Since the "cpufreq_stats" module
provides information wrt each P-state, it is not applicable to the PCC driver.

55
Documentation/cpu-hotplug.txt
View File

@@ -49,6 +49,12 @@ maxcpus=n Restrict boot time cpus to n. Say if you have 4 cpus, using
additional_cpus=n (*) Use this to limit hotpluggable cpus. This option sets
cpu_possible_map = cpu_present_map + additional_cpus
cede_offline={"off","on"} Use this option to disable/enable putting offlined
processors to an extended H_CEDE state on
supported pseries platforms.
If nothing is specified,
cede_offline is set to "on".
(*) Option valid only for following architectures
- ia64
@@ -309,41 +315,26 @@ A: The following are what is required for CPU hotplug infrastructure to work
Q: I need to ensure that a particular cpu is not removed when there is some
work specific to this cpu is in progress.
A: First switch the current thread context to preferred cpu
A: There are two ways. If your code can be run in interrupt context, use
smp_call_function_single(), otherwise use work_on_cpu(). Note that
work_on_cpu() is slow, and can fail due to out of memory:
int my_func_on_cpu(int cpu)
{
cpumask_t saved_mask, new_mask = CPU_MASK_NONE;
int curr_cpu, err = 0;
saved_mask = current->cpus_allowed;
cpu_set(cpu, new_mask);
err = set_cpus_allowed(current, new_mask);
if (err)
return err;
/*
* If we got scheduled out just after the return from
* set_cpus_allowed() before running the work, this ensures
* we stay locked.
*/
curr_cpu = get_cpu();
if (curr_cpu != cpu) {
err = -EAGAIN;
goto ret;
} else {
/*
* Do work : But cant sleep, since get_cpu() disables preempt
*/
}
ret:
put_cpu();
set_cpus_allowed(current, saved_mask);
return err;
}
int err;
get_online_cpus();
if (!cpu_online(cpu))
err = -EINVAL;
else
#if NEEDS_BLOCKING
err = work_on_cpu(cpu, __my_func_on_cpu, NULL);
#else
smp_call_function_single(cpu, __my_func_on_cpu, &err,
true);
#endif
put_online_cpus();
return err;
}
Q: How do we determine how many CPUs are available for hotplug.
A: There is no clear spec defined way from ACPI that can give us that

108
Documentation/device-mapper/snapshot.txt
View File

@@ -8,13 +8,19 @@ the block device which are also writable without interfering with the
original content;
*) To create device "forks", i.e. multiple different versions of the
same data stream.
*) To merge a snapshot of a block device back into the snapshot's origin
device.
In the first two cases, dm copies only the chunks of data that get
changed and uses a separate copy-on-write (COW) block device for
storage.
For snapshot merge the contents of the COW storage are merged back into
the origin device.
In both cases, dm copies only the chunks of data that get changed and
uses a separate copy-on-write (COW) block device for storage.
There are two dm targets available: snapshot and snapshot-origin.
There are three dm targets available:
snapshot, snapshot-origin, and snapshot-merge.
*) snapshot-origin <origin>
@@ -40,8 +46,25 @@ The difference is that for transient snapshots less metadata must be
saved on disk - they can be kept in memory by the kernel.
How this is used by LVM2
========================
* snapshot-merge <origin> <COW device> <persistent> <chunksize>
takes the same table arguments as the snapshot target except it only
works with persistent snapshots. This target assumes the role of the
"snapshot-origin" target and must not be loaded if the "snapshot-origin"
is still present for <origin>.
Creates a merging snapshot that takes control of the changed chunks
stored in the <COW device> of an existing snapshot, through a handover
procedure, and merges these chunks back into the <origin>. Once merging
has started (in the background) the <origin> may be opened and the merge
will continue while I/O is flowing to it. Changes to the <origin> are
deferred until the merging snapshot's corresponding chunk(s) have been
merged. Once merging has started the snapshot device, associated with
the "snapshot" target, will return -EIO when accessed.
How snapshot is used by LVM2
============================
When you create the first LVM2 snapshot of a volume, four dm devices are used:
1) a device containing the original mapping table of the source volume;
@@ -72,3 +95,74 @@ brw------- 1 root root 254, 12 29 ago 18:15 /dev/mapper/volumeGroup-snap-cow
brw------- 1 root root 254, 13 29 ago 18:15 /dev/mapper/volumeGroup-snap
brw------- 1 root root 254, 10 29 ago 18:14 /dev/mapper/volumeGroup-base
How snapshot-merge is used by LVM2
==================================
A merging snapshot assumes the role of the "snapshot-origin" while
merging. As such the "snapshot-origin" is replaced with
"snapshot-merge". The "-real" device is not changed and the "-cow"
device is renamed to <origin name>-cow to aid LVM2's cleanup of the
merging snapshot after it completes. The "snapshot" that hands over its
COW device to the "snapshot-merge" is deactivated (unless using lvchange
--refresh); but if it is left active it will simply return I/O errors.
A snapshot will merge into its origin with the following command:
lvconvert --merge volumeGroup/snap
we'll now have this situation:
# dmsetup table|grep volumeGroup
volumeGroup-base-real: 0 2097152 linear 8:19 384
volumeGroup-base-cow: 0 204800 linear 8:19 2097536
volumeGroup-base: 0 2097152 snapshot-merge 254:11 254:12 P 16
# ls -lL /dev/mapper/volumeGroup-*
brw------- 1 root root 254, 11 29 ago 18:15 /dev/mapper/volumeGroup-base-real
brw------- 1 root root 254, 12 29 ago 18:16 /dev/mapper/volumeGroup-base-cow
brw------- 1 root root 254, 10 29 ago 18:16 /dev/mapper/volumeGroup-base
How to determine when a merging is complete
===========================================
The snapshot-merge and snapshot status lines end with:
<sectors_allocated>/<total_sectors> <metadata_sectors>
Both <sectors_allocated> and <total_sectors> include both data and metadata.
During merging, the number of sectors allocated gets smaller and
smaller. Merging has finished when the number of sectors holding data
is zero, in other words <sectors_allocated> == <metadata_sectors>.
Here is a practical example (using a hybrid of lvm and dmsetup commands):
# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
base volumeGroup owi-a- 4.00g
snap volumeGroup swi-a- 1.00g base 18.97
# dmsetup status volumeGroup-snap
0 8388608 snapshot 397896/2097152 1560
^^^^ metadata sectors
# lvconvert --merge -b volumeGroup/snap
Merging of volume snap started.
# lvs volumeGroup/snap
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
base volumeGroup Owi-a- 4.00g 17.23
# dmsetup status volumeGroup-base
0 8388608 snapshot-merge 281688/2097152 1104
# dmsetup status volumeGroup-base
0 8388608 snapshot-merge 180480/2097152 712
# dmsetup status volumeGroup-base
0 8388608 snapshot-merge 16/2097152 16
Merging has finished.
# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
base volumeGroup owi-a- 4.00g

2
Documentation/dontdiff
View File

@@ -69,7 +69,6 @@ av_permissions.h
bbootsect
bin2c
binkernel.spec
binoffset
bootsect
bounds.h
bsetup
@@ -103,6 +102,7 @@ gconf
gen-devlist
gen_crc32table
gen_init_cpio
generated
genheaders
genksyms
*_gray256.c

4
Documentation/driver-model/driver.txt
View File

@@ -226,5 +226,5 @@ struct driver_attribute driver_attr_debug;
This can then be used to add and remove the attribute from the
driver's directory using:
int driver_create_file(struct device_driver *, struct driver_attribute *);
void driver_remove_file(struct device_driver *, struct driver_attribute *);
int driver_create_file(struct device_driver *, const struct driver_attribute *);
void driver_remove_file(struct device_driver *, const struct driver_attribute *);

23
Documentation/dvb/get_dvb_firmware
View File

@@ -26,7 +26,7 @@ use IO::Handle;
"dec3000s", "vp7041", "dibusb", "nxt2002", "nxt2004",
"or51211", "or51132_qam", "or51132_vsb", "bluebird",
"opera1", "cx231xx", "cx18", "cx23885", "pvrusb2", "mpc718",
"af9015");
"af9015", "ngene");
# Check args
syntax() if (scalar(@ARGV) != 1);
@@ -39,7 +39,7 @@ for ($i=0; $i < scalar(@components); $i++) {
die $@ if $@;
print STDERR <<EOF;
Firmware(s) $outfile extracted successfully.
Now copy it(they) to either /usr/lib/hotplug/firmware or /lib/firmware
Now copy it(them) to either /usr/lib/hotplug/firmware or /lib/firmware
(depending on configuration of firmware hotplug).
EOF
exit(0);
@@ -549,6 +549,24 @@ sub af9015 {
close INFILE;
}
sub ngene {
my $url = "http://www.digitaldevices.de/download/";
my $file1 = "ngene_15.fw";
my $hash1 = "d798d5a757121174f0dbc5f2833c0c85";
my $file2 = "ngene_17.fw";
my $hash2 = "26b687136e127b8ac24b81e0eeafc20b";
checkstandard();
wgetfile($file1, $url . $file1);
verify($file1, $hash1);
wgetfile($file2, $url . $file2);
verify($file2, $hash2);
"$file1, $file2";
}
# ---------------------------------------------------------------
# Utilities
@@ -667,6 +685,7 @@ sub delzero{
sub syntax() {
print STDERR "syntax: get_dvb_firmware <component>\n";
print STDERR "Supported components:\n";
@components = sort @components;
for($i=0; $i < scalar(@components); $i++) {
print STDERR "\t" . $components[$i] . "\n";
}

4
Documentation/fault-injection/fault-injection.txt
View File

@@ -143,8 +143,8 @@ o provide a way to configure fault attributes
failslab, fail_page_alloc, and fail_make_request use this way.
Helper functions:
init_fault_attr_entries(entries, attr, name);
void cleanup_fault_attr_entries(entries);
init_fault_attr_dentries(entries, attr, name);
void cleanup_fault_attr_dentries(entries);
- module parameters

38
Documentation/fault-injection/provoke-crashes.txt Normal file
View File

@@ -0,0 +1,38 @@
The lkdtm module provides an interface to crash or injure the kernel at
predefined crashpoints to evaluate the reliability of crash dumps obtained
using different dumping solutions. The module uses KPROBEs to instrument
crashing points, but can also crash the kernel directly without KRPOBE
support.
You can provide the way either through module arguments when inserting
the module, or through a debugfs interface.
Usage: insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<>
[cpoint_count={>0}]
recur_count : Recursion level for the stack overflow test. Default is 10.
cpoint_name : Crash point where the kernel is to be crashed. It can be
one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY,
FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD,
IDE_CORE_CP, DIRECT
cpoint_type : Indicates the action to be taken on hitting the crash point.
It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW,
CORRUPT_STACK, UNALIGNED_LOAD_STORE_WRITE, OVERWRITE_ALLOCATION,
WRITE_AFTER_FREE,
cpoint_count : Indicates the number of times the crash point is to be hit
to trigger an action. The default is 10.
You can also induce failures by mounting debugfs and writing the type to
<mountpoint>/provoke-crash/<crashpoint>. E.g.,
mount -t debugfs debugfs /mnt
echo EXCEPTION > /mnt/provoke-crash/INT_HARDWARE_ENTRY
A special file is `DIRECT' which will induce the crash directly without
KPROBE instrumentation. This mode is the only one available when the module
is built on a kernel without KPROBEs support.

12
Documentation/fb/viafb.txt
View File

@@ -7,7 +7,7 @@
VIA UniChrome Family(CLE266, PM800 / CN400 / CN300,
P4M800CE / P4M800Pro / CN700 / VN800,
CX700 / VX700, K8M890, P4M890,
CN896 / P4M900, VX800)
CN896 / P4M900, VX800, VX855)
[Driver features]
------------------------
@@ -154,13 +154,6 @@
0 : No Dual Edge Panel (default)
1 : Dual Edge Panel
viafb_video_dev:
This option is used to specify video output devices(CRT, DVI, LCD) for
duoview case.
For example:
To output video on DVI, we should use:
modprobe viafb viafb_video_dev=DVI...
viafb_lcd_port:
This option is used to specify LCD output port,
available values are "DVP0" "DVP1" "DFP_HIGHLOW" "DFP_HIGH" "DFP_LOW".
@@ -181,9 +174,6 @@ Notes:
and bpp, need to call VIAFB specified ioctl interface VIAFB_SET_DEVICE
instead of calling common ioctl function FBIOPUT_VSCREENINFO since
viafb doesn't support multi-head well, or it will cause screen crush.
4. VX800 2D accelerator hasn't been supported in this driver yet. When
using driver on VX800, the driver will disable the acceleration
function as default.
[Configure viafb with "fbset" tool]

212
Documentation/feature-removal-schedule.txt
View File

@@ -6,21 +6,6 @@ be removed from this file.
---------------------------
What: USER_SCHED
When: 2.6.34
Why: USER_SCHED was implemented as a proof of concept for group scheduling.
The effect of USER_SCHED can already be achieved from userspace with
the help of libcgroup. The removal of USER_SCHED will also simplify
the scheduler code with the removal of one major ifdef. There are also
issues USER_SCHED has with USER_NS. A decision was taken not to fix
those and instead remove USER_SCHED. Also new group scheduling
features will not be implemented for USER_SCHED.
Who: Dhaval Giani <dhaval@linux.vnet.ibm.com>
---------------------------
What: PRISM54
When: 2.6.34
@@ -64,6 +49,17 @@ Who: Robin Getz <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com>
---------------------------
What: Deprecated snapshot ioctls
When: 2.6.36
Why: The ioctls in kernel/power/user.c were marked as deprecated long time
ago. Now they notify users about that so that they need to replace
their userspace. After some more time, remove them completely.
Who: Jiri Slaby <jirislaby@gmail.com>
---------------------------
What: The ieee80211_regdom module parameter
When: March 2010 / desktop catchup
@@ -88,27 +84,6 @@ Who: Luis R. Rodriguez <lrodriguez@atheros.com>
---------------------------
What: CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information
When: March 2010 / desktop catchup
Why: The old regulatory infrastructure has been replaced with a new one
which does not require statically defined regulatory domains. We do
not want to keep static regulatory domains in the kernel due to the
the dynamic nature of regulatory law and localization. We kept around
the old static definitions for the regulatory domains of:
* US
* JP
* EU
and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
set. We will remove this option once the standard Linux desktop catches
up with the new userspace APIs we have implemented.
Who: Luis R. Rodriguez <lrodriguez@atheros.com>
---------------------------
What: dev->power.power_state
When: July 2007
Why: Broken design for runtime control over driver power states, confusing
@@ -142,19 +117,25 @@ Who: Mauro Carvalho Chehab <mchehab@infradead.org>
---------------------------
What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
When: November 2005
When: 2.6.35/2.6.36
Files: drivers/pcmcia/: pcmcia_ioctl.c
Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
normal hotpluggable bus, and with it using the default kernel
infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
control ioctl needed by cardmgr and cardctl from pcmcia-cs is
unnecessary, and makes further cleanups and integration of the
unnecessary and potentially harmful (it does not provide for
proper locking), and makes further cleanups and integration of the
PCMCIA subsystem into the Linux kernel device driver model more
difficult. The features provided by cardmgr and cardctl are either
handled by the kernel itself now or are available in the new
pcmciautils package available at
http://kernel.org/pub/linux/utils/kernel/pcmcia/
Who: Dominik Brodowski <linux@brodo.de>
For all architectures except ARM, the associated config symbol
has been removed from kernel 2.6.34; for ARM, it will be likely
be removed from kernel 2.6.35. The actual code will then likely
be removed from kernel 2.6.36.
Who: Dominik Brodowski <linux@dominikbrodowski.net>
---------------------------
@@ -291,22 +272,6 @@ Who: Michael Buesch <mb@bu3sch.de>
---------------------------
What: usedac i386 kernel parameter
When: 2.6.27
Why: replaced by allowdac and no dac combination
Who: Glauber Costa <gcosta@redhat.com>
---------------------------
What: print_fn_descriptor_symbol()
When: October 2009
Why: The %pF vsprintf format provides the same functionality in a
simpler way. print_fn_descriptor_symbol() is deprecated but
still present to give out-of-tree modules time to change.
Who: Bjorn Helgaas <bjorn.helgaas@hp.com>
---------------------------
What: /sys/o2cb symlink
When: January 2010
Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
@@ -484,9 +449,136 @@ Who: Alok N Kataria <akataria@vmware.com>
----------------------------
What: adt7473 hardware monitoring driver
When: February 2010
Why: Obsoleted by the adt7475 driver.
Who: Jean Delvare <khali@linux-fr.org>
What: Support for lcd_switch and display_get in asus-laptop driver
When: March 2010
Why: These two features use non-standard interfaces. There are the
only features that really need multiple path to guess what's
the right method name on a specific laptop.
---------------------------
Removing them will allow to remove a lot of code an significantly
clean the drivers.
This will affect the backlight code which won't be able to know
if the backlight is on or off. The platform display file will also be
write only (like the one in eeepc-laptop).
This should'nt affect a lot of user because they usually know
when their display is on or off.
Who: Corentin Chary <corentin.chary@gmail.com>
----------------------------
What: usbvideo quickcam_messenger driver
When: 2.6.35
Files: drivers/media/video/usbvideo/quickcam_messenger.[ch]
Why: obsolete v4l1 driver replaced by gspca_stv06xx
Who: Hans de Goede <hdegoede@redhat.com>
----------------------------
What: ov511 v4l1 driver
When: 2.6.35
Files: drivers/media/video/ov511.[ch]
Why: obsolete v4l1 driver replaced by gspca_ov519
Who: Hans de Goede <hdegoede@redhat.com>
----------------------------
What: w9968cf v4l1 driver
When: 2.6.35
Files: drivers/media/video/w9968cf*.[ch]
Why: obsolete v4l1 driver replaced by gspca_ov519
Who: Hans de Goede <hdegoede@redhat.com>
----------------------------
What: ovcamchip sensor framework
When: 2.6.35
Files: drivers/media/video/ovcamchip/*
Why: Only used by obsoleted v4l1 drivers
Who: Hans de Goede <hdegoede@redhat.com>
----------------------------
What: stv680 v4l1 driver
When: 2.6.35
Files: drivers/media/video/stv680.[ch]
Why: obsolete v4l1 driver replaced by gspca_stv0680
Who: Hans de Goede <hdegoede@redhat.com>
----------------------------
What: zc0301 v4l driver
When: 2.6.35
Files: drivers/media/video/zc0301/*
Why: Duplicate functionality with the gspca_zc3xx driver, zc0301 only
supports 2 USB-ID's (because it only supports a limited set of
sensors) wich are also supported by the gspca_zc3xx driver
(which supports 53 USB-ID's in total)
Who: Hans de Goede <hdegoede@redhat.com>
----------------------------
What: corgikbd, spitzkbd, tosakbd driver
When: 2.6.35
Files: drivers/input/keyboard/{corgi,spitz,tosa}kbd.c
Why: We now have a generic GPIO based matrix keyboard driver that
are fully capable of handling all the keys on these devices.
The original drivers manipulate the GPIO registers directly
and so are difficult to maintain.
Who: Eric Miao <eric.y.miao@gmail.com>
----------------------------
What: corgi_ssp and corgi_ts driver
When: 2.6.35
Files: arch/arm/mach-pxa/corgi_ssp.c, drivers/input/touchscreen/corgi_ts.c
Why: The corgi touchscreen is now deprecated in favour of the generic
ads7846.c driver. The noise reduction technique used in corgi_ts.c,
that's to wait till vsync before ADC sampling, is also integrated into
ads7846 driver now. Provided that the original driver is not generic
and is difficult to maintain, it will be removed later.
Who: Eric Miao <eric.y.miao@gmail.com>
----------------------------
What: capifs
When: February 2011
Files: drivers/isdn/capi/capifs.*
Why: udev fully replaces this special file system that only contains CAPI
NCCI TTY device nodes. User space (pppdcapiplugin) works without
noticing the difference.
Who: Jan Kiszka <jan.kiszka@web.de>
----------------------------
What: KVM memory aliases support
When: July 2010
Why: Memory aliasing support is used for speeding up guest vga access
through the vga windows.
Modern userspace no longer uses this feature, so it's just bitrotted
code and can be removed with no impact.
Who: Avi Kivity <avi@redhat.com>
----------------------------
What: KVM kernel-allocated memory slots
When: July 2010
Why: Since 2.6.25, kvm supports user-allocated memory slots, which are
much more flexible than kernel-allocated slots. All current userspace
supports the newer interface and this code can be removed with no
impact.
Who: Avi Kivity <avi@redhat.com>
----------------------------
What: KVM paravirt mmu host support
When: January 2011
Why: The paravirt mmu host support is slower than non-paravirt mmu, both
on newer and older hardware. It is already not exposed to the guest,
and kept only for live migration purposes.
Who: Avi Kivity <avi@redhat.com>
----------------------------

14
Documentation/filesystems/00-INDEX
View File

@@ -1,7 +1,5 @@
00-INDEX
- this file (info on some of the filesystems supported by linux).
Exporting
- explanation of how to make filesystems exportable.
Locking
- info on locking rules as they pertain to Linux VFS.
9p.txt
@@ -64,16 +62,14 @@ jfs.txt
- info and mount options for the JFS filesystem.
locks.txt
- info on file locking implementations, flock() vs. fcntl(), etc.
logfs.txt
- info on the LogFS flash filesystem.
mandatory-locking.txt
- info on the Linux implementation of Sys V mandatory file locking.
ncpfs.txt
- info on Novell Netware(tm) filesystem using NCP protocol.
nfs41-server.txt
- info on the Linux server implementation of NFSv4 minor version 1.
nfs-rdma.txt
- how to install and setup the Linux NFS/RDMA client and server software.
nfsroot.txt
- short guide on setting up a diskless box with NFS root filesystem.
nfs/
- nfs-related documentation.
nilfs2.txt
- info and mount options for the NILFS2 filesystem.
ntfs.txt
@@ -92,8 +88,6 @@ relay.txt
- info on relay, for efficient streaming from kernel to user space.
romfs.txt
- description of the ROMFS filesystem.
rpc-cache.txt
- introduction to the caching mechanisms in the sunrpc layer.
seq_file.txt
- how to use the seq_file API
sharedsubtree.txt

18
Documentation/filesystems/Locking
View File

@@ -460,13 +460,6 @@ in sys_read() and friends.
--------------------------- dquot_operations -------------------------------
prototypes:
int (*initialize) (struct inode *, int);
int (*drop) (struct inode *);
int (*alloc_space) (struct inode *, qsize_t, int);
int (*alloc_inode) (const struct inode *, unsigned long);
int (*free_space) (struct inode *, qsize_t);
int (*free_inode) (const struct inode *, unsigned long);
int (*transfer) (struct inode *, struct iattr *);
int (*write_dquot) (struct dquot *);
int (*acquire_dquot) (struct dquot *);
int (*release_dquot) (struct dquot *);
@@ -479,13 +472,6 @@ a proper locking wrt the filesystem and call the generic quota operations.
What filesystem should expect from the generic quota functions:
FS recursion Held locks when called
initialize: yes maybe dqonoff_sem
drop: yes -
alloc_space: ->mark_dirty() -
alloc_inode: ->mark_dirty() -
free_space: ->mark_dirty() -
free_inode: ->mark_dirty() -
transfer: yes -
write_dquot: yes dqonoff_sem or dqptr_sem
acquire_dquot: yes dqonoff_sem or dqptr_sem
release_dquot: yes dqonoff_sem or dqptr_sem
@@ -495,10 +481,6 @@ write_info: yes dqonoff_sem
FS recursion means calling ->quota_read() and ->quota_write() from superblock
operations.
->alloc_space(), ->alloc_inode(), ->free_space(), ->free_inode() are called
only directly by the filesystem and do not call any fs functions only
the ->mark_dirty() operation.
More details about quota locking can be found in fs/dquot.c.
--------------------------- vm_operations_struct -----------------------------

3
Documentation/filesystems/dentry-locking.txt
View File

@@ -62,7 +62,8 @@ changes are :
2. Insertion of a dentry into the hash table is done using
hlist_add_head_rcu() which take care of ordering the writes - the
writes to the dentry must be visible before the dentry is
inserted. This works in conjunction with hlist_for_each_rcu() while
inserted. This works in conjunction with hlist_for_each_rcu(),
which has since been replaced by hlist_for_each_entry_rcu(), while
walking the hash chain. The only requirement is that all
initialization to the dentry must be done before
hlist_add_head_rcu() since we don't have dcache_lock protection

2
Documentation/filesystems/ext4.txt
View File

@@ -196,7 +196,7 @@ nobarrier This also requires an IO stack which can support
also be used to enable or disable barriers, for
consistency with other ext4 mount options.
inode_readahead=n This tuning parameter controls the maximum
inode_readahead_blks=n This tuning parameter controls the maximum
number of inode table blocks that ext4's inode
table readahead algorithm will pre-read into
the buffer cache. The default value is 32 blocks.

241
Documentation/filesystems/logfs.txt Normal file
View File

@@ -0,0 +1,241 @@
The LogFS Flash Filesystem
==========================
Specification
=============
Superblocks
-----------
Two superblocks exist at the beginning and end of the filesystem.
Each superblock is 256 Bytes large, with another 3840 Bytes reserved
for future purposes, making a total of 4096 Bytes.
Superblock locations may differ for MTD and block devices. On MTD the
first non-bad block contains a superblock in the first 4096 Bytes and
the last non-bad block contains a superblock in the last 4096 Bytes.
On block devices, the first 4096 Bytes of the device contain the first
superblock and the last aligned 4096 Byte-block contains the second
superblock.
For the most part, the superblocks can be considered read-only. They
are written only to correct errors detected within the superblocks,
move the journal and change the filesystem parameters through tunefs.
As a result, the superblock does not contain any fields that require
constant updates, like the amount of free space, etc.
Segments
--------
The space in the device is split up into equal-sized segments.
Segments are the primary write unit of LogFS. Within each segments,
writes happen from front (low addresses) to back (high addresses. If
only a partial segment has been written, the segment number, the
current position within and optionally a write buffer are stored in
the journal.
Segments are erased as a whole. Therefore Garbage Collection may be
required to completely free a segment before doing so.
Journal
--------
The journal contains all global information about the filesystem that
is subject to frequent change. At mount time, it has to be scanned
for the most recent commit entry, which contains a list of pointers to
all currently valid entries.
Object Store
------------
All space except for the superblocks and journal is part of the object
store. Each segment contains a segment header and a number of
objects, each consisting of the object header and the payload.
Objects are either inodes, directory entries (dentries), file data
blocks or indirect blocks.
Levels
------
Garbage collection (GC) may fail if all data is written
indiscriminately. One requirement of GC is that data is seperated
roughly according to the distance between the tree root and the data.
Effectively that means all file data is on level 0, indirect blocks
are on levels 1, 2, 3 4 or 5 for 1x, 2x, 3x, 4x or 5x indirect blocks,
respectively. Inode file data is on level 6 for the inodes and 7-11
for indirect blocks.
Each segment contains objects of a single level only. As a result,
each level requires its own seperate segment to be open for writing.
Inode File
----------
All inodes are stored in a special file, the inode file. Single
exception is the inode file's inode (master inode) which for obvious
reasons is stored in the journal instead. Instead of data blocks, the
leaf nodes of the inode files are inodes.
Aliases
-------
Writes in LogFS are done by means of a wandering tree. A naïve
implementation would require that for each write or a block, all
parent blocks are written as well, since the block pointers have
changed. Such an implementation would not be very efficient.
In LogFS, the block pointer changes are cached in the journal by means
of alias entries. Each alias consists of its logical address - inode
number, block index, level and child number (index into block) - and
the changed data. Any 8-byte word can be changes in this manner.
Currently aliases are used for block pointers, file size, file used
bytes and the height of an inodes indirect tree.
Segment Aliases
---------------
Related to regular aliases, these are used to handle bad blocks.
Initially, bad blocks are handled by moving the affected segment
content to a spare segment and noting this move in the journal with a
segment alias, a simple (to, from) tupel. GC will later empty this
segment and the alias can be removed again. This is used on MTD only.
Vim
---
By cleverly predicting the life time of data, it is possible to
seperate long-living data from short-living data and thereby reduce
the GC overhead later. Each type of distinc life expectency (vim) can
have a seperate segment open for writing. Each (level, vim) tupel can
be open just once. If an open segment with unknown vim is encountered
at mount time, it is closed and ignored henceforth.
Indirect Tree
-------------
Inodes in LogFS are similar to FFS-style filesystems with direct and
indirect block pointers. One difference is that LogFS uses a single
indirect pointer that can be either a 1x, 2x, etc. indirect pointer.
A height field in the inode defines the height of the indirect tree
and thereby the indirection of the pointer.
Another difference is the addressing of indirect blocks. In LogFS,
the first 16 pointers in the first indirect block are left empty,
corresponding to the 16 direct pointers in the inode. In ext2 (maybe
others as well) the first pointer in the first indirect block
corresponds to logical block 12, skipping the 12 direct pointers.
So where ext2 is using arithmetic to better utilize space, LogFS keeps
arithmetic simple and uses compression to save space.
Compression
-----------
Both file data and metadata can be compressed. Compression for file
data can be enabled with chattr +c and disabled with chattr -c. Doing
so has no effect on existing data, but new data will be stored
accordingly. New inodes will inherit the compression flag of the
parent directory.
Metadata is always compressed. However, the space accounting ignores
this and charges for the uncompressed size. Failing to do so could
result in GC failures when, after moving some data, indirect blocks
compress worse than previously. Even on a 100% full medium, GC may
not consume any extra space, so the compression gains are lost space
to the user.
However, they are not lost space to the filesystem internals. By
cheating the user for those bytes, the filesystem gained some slack
space and GC will run less often and faster.
Garbage Collection and Wear Leveling
------------------------------------
Garbage collection is invoked whenever the number of free segments
falls below a threshold. The best (known) candidate is picked based
on the least amount of valid data contained in the segment. All
remaining valid data is copied elsewhere, thereby invalidating it.
The GC code also checks for aliases and writes then back if their
number gets too large.
Wear leveling is done by occasionally picking a suboptimal segment for
garbage collection. If a stale segments erase count is significantly
lower than the active segments' erase counts, it will be picked. Wear
leveling is rate limited, so it will never monopolize the device for
more than one segment worth at a time.
Values for "occasionally", "significantly lower" are compile time
constants.
Hashed directories
------------------
To satisfy efficient lookup(), directory entries are hashed and
located based on the hash. In order to both support large directories
and not be overly inefficient for small directories, several hash
tables of increasing size are used. For each table, the hash value
modulo the table size gives the table index.
Tables sizes are chosen to limit the number of indirect blocks with a
fully populated table to 0, 1, 2 or 3 respectively. So the first
table contains 16 entries, the second 512-16, etc.
The last table is special in several ways. First its size depends on
the effective 32bit limit on telldir/seekdir cookies. Since logfs
uses the upper half of the address space for indirect blocks, the size
is limited to 2^31. Secondly the table contains hash buckets with 16
entries each.
Using single-entry buckets would result in birthday "attacks". At
just 2^16 used entries, hash collisions would be likely (P >= 0.5).
My math skills are insufficient to do the combinatorics for the 17x
collisions necessary to overflow a bucket, but testing showed that in
10,000 runs the lowest directory fill before a bucket overflow was
188,057,130 entries with an average of 315,149,915 entries. So for
directory sizes of up to a million, bucket overflows should be
virtually impossible under normal circumstances.
With carefully chosen filenames, it is obviously possible to cause an
overflow with just 21 entries (4 higher tables + 16 entries + 1). So
there may be a security concern if a malicious user has write access
to a directory.
Open For Discussion
===================
Device Address Space
--------------------
A device address space is used for caching. Both block devices and
MTD provide functions to either read a single page or write a segment.
Partial segments may be written for data integrity, but where possible
complete segments are written for performance on simple block device
flash media.
Meta Inodes
-----------
Inodes are stored in the inode file, which is just a regular file for
most purposes. At umount time, however, the inode file needs to
remain open until all dirty inodes are written. So
generic_shutdown_super() may not close this inode, but shouldn't
complain about remaining inodes due to the inode file either. Same
goes for mapping inode of the device address space.
Currently logfs uses a hack that essentially copies part of fs/inode.c
code over. A general solution would be preferred.
Indirect block mapping
----------------------
With compression, the block device (or mapping inode) cannot be used
to cache indirect blocks. Some other place is required. Currently
logfs uses the top half of each inode's address space. The low 8TB
(on 32bit) are filled with file data, the high 8TB are used for
indirect blocks.
One problem is that 16TB files created on 64bit systems actually have
data in the top 8TB. But files >16TB would cause problems anyway, so
only the limit has changed.

16
Documentation/filesystems/nfs/00-INDEX Normal file
View File

@@ -0,0 +1,16 @@
00-INDEX
- this file (nfs-related documentation).
Exporting
- explanation of how to make filesystems exportable.
knfsd-stats.txt
- statistics which the NFS server makes available to user space.
nfs.txt
- nfs client, and DNS resolution for fs_locations.
nfs41-server.txt
- info on the Linux server implementation of NFSv4 minor version 1.
nfs-rdma.txt
- how to install and setup the Linux NFS/RDMA client and server software
nfsroot.txt
- short guide on setting up a diskless box with NFS root filesystem.
rpc-cache.txt
- introduction to the caching mechanisms in the sunrpc layer.

0
Documentation/filesystems/Exporting → Documentation/filesystems/nfs/Exporting
View File

0
Documentation/filesystems/knfsd-stats.txt → Documentation/filesystems/nfs/knfsd-stats.txt
View File

0
Documentation/filesystems/nfs-rdma.txt → Documentation/filesystems/nfs/nfs-rdma.txt
View File

0
Documentation/filesystems/nfs.txt → Documentation/filesystems/nfs/nfs.txt
View File

14
Documentation/filesystems/nfs41-server.txt → Documentation/filesystems/nfs/nfs41-server.txt
View File

@@ -17,8 +17,7 @@ kernels must turn 4.1 on or off *before* turning support for version 4
on or off; rpc.nfsd does this correctly.)
The NFSv4 minorversion 1 (NFSv4.1) implementation in nfsd is based
on the latest NFSv4.1 Internet Draft:
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29
on RFC 5661.
From the many new features in NFSv4.1 the current implementation
focuses on the mandatory-to-implement NFSv4.1 Sessions, providing
@@ -41,10 +40,10 @@ interoperability problems with future clients. Known issues:
conformant with the spec (for example, we don't use kerberos
on the backchannel correctly).
- no trunking support: no clients currently take advantage of
trunking, but this is a mandatory failure, and its use is
trunking, but this is a mandatory feature, and its use is
recommended to clients in a number of places. (E.g. to ensure
timely renewal in case an existing connection's retry timeouts
have gotten too long; see section 8.3 of the draft.)
have gotten too long; see section 8.3 of the RFC.)
Therefore, lack of this feature may cause future clients to
fail.
- Incomplete backchannel support: incomplete backchannel gss
@@ -213,3 +212,10 @@ The following cases aren't supported yet:
DESTROY_CLIENTID, DESTROY_SESSION, EXCHANGE_ID.
* DESTROY_SESSION MUST be the final operation in the COMPOUND request.
Nonstandard compound limitations:
* No support for a sessions fore channel RPC compound that requires both a
ca_maxrequestsize request and a ca_maxresponsesize reply, so we may
fail to live up to the promise we made in CREATE_SESSION fore channel
negotiation.
* No more than one IO operation (read, write, readdir) allowed per
compound.

0
Documentation/filesystems/nfsroot.txt → Documentation/filesystems/nfs/nfsroot.txt
View File

0
Documentation/filesystems/rpc-cache.txt → Documentation/filesystems/nfs/rpc-cache.txt
View File

5
Documentation/filesystems/nilfs2.txt
View File

@@ -28,7 +28,7 @@ described in the man pages included in the package.
Project web page: http://www.nilfs.org/en/
Download page: http://www.nilfs.org/en/download.html
Git tree web page: http://www.nilfs.org/git/
NILFS mailing lists: http://www.nilfs.org/mailman/listinfo/users
List info: http://vger.kernel.org/vger-lists.html#linux-nilfs
Caveats
=======
@@ -74,6 +74,9 @@ norecovery Disable recovery of the filesystem on mount.
This disables every write access on the device for
read-only mounts or snapshots. This option will fail
for r/w mounts on an unclean volume.
discard Issue discard/TRIM commands to the underlying block
device when blocks are freed. This is useful for SSD
devices and sparse/thinly-provisioned LUNs.
NILFS2 usage
============

2
Documentation/filesystems/porting
View File

@@ -140,7 +140,7 @@ Callers of notify_change() need ->i_mutex now.
New super_block field "struct export_operations *s_export_op" for
explicit support for exporting, e.g. via NFS. The structure is fully
documented at its declaration in include/linux/fs.h, and in
Documentation/filesystems/Exporting.
Documentation/filesystems/nfs/Exporting.
Briefly it allows for the definition of decode_fh and encode_fh operations
to encode and decode filehandles, and allows the filesystem to use

64
Documentation/filesystems/proc.txt
View File

@@ -38,6 +38,7 @@ Table of Contents
3.3 /proc/<pid>/io - Display the IO accounting fields
3.4 /proc/<pid>/coredump_filter - Core dump filtering settings
3.5 /proc/<pid>/mountinfo - Information about mounts
3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
------------------------------------------------------------------------------
@@ -163,6 +164,7 @@ read the file /proc/PID/status:
VmExe: 68 kB
VmLib: 1412 kB
VmPTE: 20 kb
VmSwap: 0 kB
Threads: 1
SigQ: 0/28578
SigPnd: 0000000000000000
@@ -176,7 +178,6 @@ read the file /proc/PID/status:
CapBnd: ffffffffffffffff
voluntary_ctxt_switches: 0
nonvoluntary_ctxt_switches: 1
Stack usage: 12 kB
This shows you nearly the same information you would get if you viewed it with
the ps command. In fact, ps uses the proc file system to obtain its
@@ -188,6 +189,12 @@ memory usage. Its seven fields are explained in Table 1-3. The stat file
contains details information about the process itself. Its fields are
explained in Table 1-4.
(for SMP CONFIG users)
For making accounting scalable, RSS related information are handled in
asynchronous manner and the vaule may not be very precise. To see a precise
snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
It's slow but very precise.
Table 1-2: Contents of the statm files (as of 2.6.30-rc7)
..............................................................................
Field Content
@@ -213,6 +220,7 @@ Table 1-2: Contents of the statm files (as of 2.6.30-rc7)
VmExe size of text segment
VmLib size of shared library code
VmPTE size of page table entries
VmSwap size of swap usage (the number of referred swapents)
Threads number of threads
SigQ number of signals queued/max. number for queue
SigPnd bitmap of pending signals for the thread
@@ -230,7 +238,6 @@ Table 1-2: Contents of the statm files (as of 2.6.30-rc7)
Mems_allowed_list Same as previous, but in "list format"
voluntary_ctxt_switches number of voluntary context switches
nonvoluntary_ctxt_switches number of non voluntary context switches
Stack usage: stack usage high water mark (round up to page size)
..............................................................................
Table 1-3: Contents of the statm files (as of 2.6.8-rc3)
@@ -431,6 +438,7 @@ Table 1-5: Kernel info in /proc
modules List of loaded modules
mounts Mounted filesystems
net Networking info (see text)
pagetypeinfo Additional page allocator information (see text) (2.5)
partitions Table of partitions known to the system
pci Deprecated info of PCI bus (new way -> /proc/bus/pci/,
decoupled by lspci (2.4)
@@ -585,7 +593,7 @@ Node 0, zone DMA 0 4 5 4 4 3 ...
Node 0, zone Normal 1 0 0 1 101 8 ...
Node 0, zone HighMem 2 0 0 1 1 0 ...
Memory fragmentation is a problem under some workloads, and buddyinfo is a
External fragmentation is a problem under some workloads, and buddyinfo is a
useful tool for helping diagnose these problems. Buddyinfo will give you a
clue as to how big an area you can safely allocate, or why a previous
allocation failed.
@@ -595,6 +603,48 @@ available. In this case, there are 0 chunks of 2^0*PAGE_SIZE available in
ZONE_DMA, 4 chunks of 2^1*PAGE_SIZE in ZONE_DMA, 101 chunks of 2^4*PAGE_SIZE
available in ZONE_NORMAL, etc...
More information relevant to external fragmentation can be found in
pagetypeinfo.
> cat /proc/pagetypeinfo
Page block order: 9
Pages per block: 512
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 0, zone DMA, type Unmovable 0 0 0 1 1 1 1 1 1 1 0
Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Movable 1 1 2 1 2 1 1 0 1 0 2
Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 1 0
Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Unmovable 103 54 77 1 1 1 11 8 7 1 9
Node 0, zone DMA32, type Reclaimable 0 0 2 1 0 0 0 0 1 0 0
Node 0, zone DMA32, type Movable 169 152 113 91 77 54 39 13 6 1 452
Node 0, zone DMA32, type Reserve 1 2 2 2 2 0 1 1 1 1 0
Node 0, zone DMA32, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Number of blocks type Unmovable Reclaimable Movable Reserve Isolate
Node 0, zone DMA 2 0 5 1 0
Node 0, zone DMA32 41 6 967 2 0
Fragmentation avoidance in the kernel works by grouping pages of different
migrate types into the same contiguous regions of memory called page blocks.
A page block is typically the size of the default hugepage size e.g. 2MB on
X86-64. By keeping pages grouped based on their ability to move, the kernel
can reclaim pages within a page block to satisfy a high-order allocation.
The pagetypinfo begins with information on the size of a page block. It
then gives the same type of information as buddyinfo except broken down
by migrate-type and finishes with details on how many page blocks of each
type exist.
If min_free_kbytes has been tuned correctly (recommendations made by hugeadm
from libhugetlbfs http://sourceforge.net/projects/libhugetlbfs/), one can
make an estimate of the likely number of huge pages that can be allocated
at a given point in time. All the "Movable" blocks should be allocatable
unless memory has been mlock()'d. Some of the Reclaimable blocks should
also be allocatable although a lot of filesystem metadata may have to be
reclaimed to achieve this.
..............................................................................
meminfo:
@@ -1409,3 +1459,11 @@ For more information on mount propagation see:
Documentation/filesystems/sharedsubtree.txt
3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
--------------------------------------------------------
These files provide a method to access a tasks comm value. It also allows for
a task to set its own or one of its thread siblings comm value. The comm value
is limited in size compared to the cmdline value, so writing anything longer
then the kernel's TASK_COMM_LEN (currently 16 chars) will result in a truncated
comm value.

4
Documentation/filesystems/seq_file.txt
View File

@@ -248,9 +248,7 @@ code, that is done in the initialization code in the usual way:
{
struct proc_dir_entry *entry;
entry = create_proc_entry("sequence", 0, NULL);
if (entry)
entry->proc_fops = &ct_file_ops;
proc_create("sequence", 0, NULL, &ct_file_ops);
return 0;
}

16
Documentation/filesystems/sharedsubtree.txt
View File

@@ -837,6 +837,9 @@ replicas continue to be exactly same.
individual lists does not affect propagation or the way propagation
tree is modified by operations.
All vfsmounts in a peer group have the same ->mnt_master. If it is
non-NULL, they form a contiguous (ordered) segment of slave list.
A example propagation tree looks as shown in the figure below.
[ NOTE: Though it looks like a forest, if we consider all the shared
mounts as a conceptual entity called 'pnode', it becomes a tree]
@@ -874,8 +877,19 @@ replicas continue to be exactly same.
NOTE: The propagation tree is orthogonal to the mount tree.
8B Locking:
8B Algorithm:
->mnt_share, ->mnt_slave, ->mnt_slave_list, ->mnt_master are protected
by namespace_sem (exclusive for modifications, shared for reading).
Normally we have ->mnt_flags modifications serialized by vfsmount_lock.
There are two exceptions: do_add_mount() and clone_mnt().
The former modifies a vfsmount that has not been visible in any shared
data structures yet.
The latter holds namespace_sem and the only references to vfsmount
are in lists that can't be traversed without namespace_sem.
8C Algorithm:
The crux of the implementation resides in rbind/move operation.

12
Documentation/filesystems/sysfs.txt
View File

@@ -91,8 +91,8 @@ struct device_attribute {
const char *buf, size_t count);
};
int device_create_file(struct device *, struct device_attribute *);
void device_remove_file(struct device *, struct device_attribute *);
int device_create_file(struct device *, const struct device_attribute *);
void device_remove_file(struct device *, const struct device_attribute *);
It also defines this helper for defining device attributes:
@@ -316,8 +316,8 @@ DEVICE_ATTR(_name, _mode, _show, _store);
Creation/Removal:
int device_create_file(struct device *device, struct device_attribute * attr);
void device_remove_file(struct device * dev, struct device_attribute * attr);
int device_create_file(struct device *dev, const struct device_attribute * attr);
void device_remove_file(struct device *dev, const struct device_attribute * attr);
- bus drivers (include/linux/device.h)
@@ -358,7 +358,7 @@ DRIVER_ATTR(_name, _mode, _show, _store)
Creation/Removal:
int driver_create_file(struct device_driver *, struct driver_attribute *);
void driver_remove_file(struct device_driver *, struct driver_attribute *);
int driver_create_file(struct device_driver *, const struct driver_attribute *);
void driver_remove_file(struct device_driver *, const struct driver_attribute *);

79
Documentation/gpio.txt
View File

@@ -253,6 +253,70 @@ pin setup (e.g. controlling which pin the GPIO uses, pullup/pulldown).
Also note that it's your responsibility to have stopped using a GPIO
before you free it.
Considering in most cases GPIOs are actually configured right after they
are claimed, three additional calls are defined:
/* request a single GPIO, with initial configuration specified by
* 'flags', identical to gpio_request() wrt other arguments and
* return value
*/
int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
/* request multiple GPIOs in a single call
*/
int gpio_request_array(struct gpio *array, size_t num);
/* release multiple GPIOs in a single call
*/
void gpio_free_array(struct gpio *array, size_t num);
where 'flags' is currently defined to specify the following properties:
* GPIOF_DIR_IN - to configure direction as input
* GPIOF_DIR_OUT - to configure direction as output
* GPIOF_INIT_LOW - as output, set initial level to LOW
* GPIOF_INIT_HIGH - as output, set initial level to HIGH
since GPIOF_INIT_* are only valid when configured as output, so group valid
combinations as:
* GPIOF_IN - configure as input
* GPIOF_OUT_INIT_LOW - configured as output, initial level LOW
* GPIOF_OUT_INIT_HIGH - configured as output, initial level HIGH
In the future, these flags can be extended to support more properties such
as open-drain status.
Further more, to ease the claim/release of multiple GPIOs, 'struct gpio' is
introduced to encapsulate all three fields as:
struct gpio {
unsigned gpio;
unsigned long flags;
const char *label;
};
A typical example of usage:
static struct gpio leds_gpios[] = {
{ 32, GPIOF_OUT_INIT_HIGH, "Power LED" }, /* default to ON */
{ 33, GPIOF_OUT_INIT_LOW, "Green LED" }, /* default to OFF */
{ 34, GPIOF_OUT_INIT_LOW, "Red LED" }, /* default to OFF */
{ 35, GPIOF_OUT_INIT_LOW, "Blue LED" }, /* default to OFF */
{ ... },
};
err = gpio_request_one(31, GPIOF_IN, "Reset Button");
if (err)
...
err = gpio_request_array(leds_gpios, ARRAY_SIZE(leds_gpios));
if (err)
...
gpio_free_array(leds_gpios, ARRAY_SIZE(leds_gpios));
GPIOs mapped to IRQs
--------------------
@@ -531,6 +595,13 @@ and have the following read/write attributes:
This file exists only if the pin can be configured as an
interrupt generating input pin.
"active_low" ... reads as either 0 (false) or 1 (true). Write
any nonzero value to invert the value attribute both
for reading and writing. Existing and subsequent
poll(2) support configuration via the edge attribute
for "rising" and "falling" edges will follow this
setting.
GPIO controllers have paths like /sys/class/gpio/gpiochip42/ (for the
controller implementing GPIOs starting at #42) and have the following
read-only attributes:
@@ -566,6 +637,8 @@ requested using gpio_request():
int gpio_export_link(struct device *dev, const char *name,
unsigned gpio)
/* change the polarity of a GPIO node in sysfs */
int gpio_sysfs_set_active_low(unsigned gpio, int value);
After a kernel driver requests a GPIO, it may only be made available in
the sysfs interface by gpio_export(). The driver can control whether the
@@ -580,3 +653,9 @@ After the GPIO has been exported, gpio_export_link() allows creating
symlinks from elsewhere in sysfs to the GPIO sysfs node. Drivers can
use this to provide the interface under their own device in sysfs with
a descriptive name.
Drivers can use gpio_sysfs_set_active_low() to hide GPIO line polarity
differences between boards from user space. This only affects the
sysfs interface. Polarity change can be done both before and after
gpio_export(), and previously enabled poll(2) support for either
rising or falling edge will be reconfigured to follow this setting.

42
Documentation/hwmon/adt7411 Normal file
View File

@@ -0,0 +1,42 @@
Kernel driver adt7411
=====================
Supported chips:
* Analog Devices ADT7411
Prefix: 'adt7411'
Addresses scanned: 0x48, 0x4a, 0x4b
Datasheet: Publicly available at the Analog Devices website
Author: Wolfram Sang (based on adt7470 by Darrick J. Wong)
Description
-----------
This driver implements support for the Analog Devices ADT7411 chip. There may
be other chips that implement this interface.
The ADT7411 can use an I2C/SMBus compatible 2-wire interface or an
SPI-compatible 4-wire interface. It provides a 10-bit analog to digital
converter which measures 1 temperature, vdd and 8 input voltages. It has an
internal temperature sensor, but an external one can also be connected (one
loses 2 inputs then). There are high- and low-limit registers for all inputs.
Check the datasheet for details.
sysfs-Interface
---------------
in0_input - vdd voltage input
in[1-8]_input - analog 1-8 input
temp1_input - temperature input
Besides standard interfaces, this driver adds (0 = off, 1 = on):
adc_ref_vdd - Use vdd as reference instead of 2.25 V
fast_sampling - Sample at 22.5 kHz instead of 1.4 kHz, but drop filters
no_average - Turn off averaging over 16 samples
Notes
-----
SPI, external temperature sensor and limit registers are not supported yet.

74
Documentation/hwmon/adt7473
View File

@@ -1,74 +0,0 @@
Kernel driver adt7473
======================
Supported chips:
* Analog Devices ADT7473
Prefix: 'adt7473'
Addresses scanned: I2C 0x2C, 0x2D, 0x2E
Datasheet: Publicly available at the Analog Devices website
Author: Darrick J. Wong
This driver is depreacted, please use the adt7475 driver instead.
Description
-----------
This driver implements support for the Analog Devices ADT7473 chip family.
The ADT7473 uses the 2-wire interface compatible with the SMBUS 2.0
specification. Using an analog to digital converter it measures three (3)
temperatures and two (2) voltages. It has four (4) 16-bit counters for
measuring fan speed. There are three (3) PWM outputs that can be used
to control fan speed.
A sophisticated control system for the PWM outputs is designed into the
ADT7473 that allows fan speed to be adjusted automatically based on any of the
three temperature sensors. Each PWM output is individually adjustable and
programmable. Once configured, the ADT7473 will adjust the PWM outputs in
response to the measured temperatures without further host intervention.
This feature can also be disabled for manual control of the PWM's.
Each of the measured inputs (voltage, temperature, fan speed) has
corresponding high/low limit values. The ADT7473 will signal an ALARM if
any measured value exceeds either limit.
The ADT7473 samples all inputs continuously. The driver will not read
the registers more often than once every other second. Further,
configuration data is only read once per minute.
Special Features
----------------
The ADT7473 have a 10-bit ADC and can therefore measure temperatures
with 0.25 degC resolution. Temperature readings can be configured either
for twos complement format or "Offset 64" format, wherein 63 is subtracted
from the raw value to get the temperature value.
The Analog Devices datasheet is very detailed and describes a procedure for
determining an optimal configuration for the automatic PWM control.
Configuration Notes
-------------------
Besides standard interfaces driver adds the following:
* PWM Control
* pwm#_auto_point1_pwm and temp#_auto_point1_temp and
* pwm#_auto_point2_pwm and temp#_auto_point2_temp -
point1: Set the pwm speed at a lower temperature bound.
point2: Set the pwm speed at a higher temperature bound.
The ADT7473 will scale the pwm between the lower and higher pwm speed when
the temperature is between the two temperature boundaries. PWM values range
from 0 (off) to 255 (full speed). Fan speed will be set to maximum when the
temperature sensor associated with the PWM control exceeds temp#_max.
Notes
-----
The NVIDIA binary driver presents an ADT7473 chip via an on-card i2c bus.
Unfortunately, they fail to set the i2c adapter class, so this driver may
fail to find the chip until the nvidia driver is patched.

102
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@@ -0,0 +1,102 @@
Kernel driver amc6821
=====================
Supported chips:
Texas Instruments AMC6821
Prefix: 'amc6821'
Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e
Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html
Authors:
Tomaz Mertelj <tomaz.mertelj@guest.arnes.si>
Description
-----------
This driver implements support for the Texas Instruments amc6821 chip.
The chip has one on-chip and one remote temperature sensor and one pwm fan
regulator.
The pwm can be controlled either from software or automatically.
The driver provides the following sensor accesses in sysfs:
temp1_input ro on-chip temperature
temp1_min rw "
temp1_max rw "
temp1_crit rw "
temp1_min_alarm ro "
temp1_max_alarm ro "
temp1_crit_alarm ro "
temp2_input ro remote temperature
temp2_min rw "
temp2_max rw "
temp2_crit rw "
temp2_min_alarm ro "
temp2_max_alarm ro "
temp2_crit_alarm ro "
temp2_fault ro "
fan1_input ro tachometer speed
fan1_min rw "
fan1_max rw "
fan1_fault ro "
fan1_div rw Fan divisor can be either 2 or 4.
pwm1 rw pwm1
pwm1_enable rw regulator mode, 1=open loop, 2=fan controlled
by remote temperature, 3=fan controlled by
combination of the on-chip temperature and
remote-sensor temperature,
pwm1_auto_channels_temp ro 1 if pwm_enable==2, 3 if pwm_enable==3
pwm1_auto_point1_pwm ro Hardwired to 0, shared for both
temperature channels.
pwm1_auto_point2_pwm rw This value is shared for both temperature
channels.
pwm1_auto_point3_pwm rw Hardwired to 255, shared for both
temperature channels.
temp1_auto_point1_temp ro Hardwired to temp2_auto_point1_temp
which is rw. Below this temperature fan stops.
temp1_auto_point2_temp rw The low-temperature limit of the proportional
range. Below this temperature
pwm1 = pwm1_auto_point2_pwm. It can go from
0 degree C to 124 degree C in steps of
4 degree C. Read it out after writing to get
the actual value.
temp1_auto_point3_temp rw Above this temperature fan runs at maximum
speed. It can go from temp1_auto_point2_temp.
It can only have certain discrete values
which depend on temp1_auto_point2_temp and
pwm1_auto_point2_pwm. Read it out after
writing to get the actual value.
temp2_auto_point1_temp rw Must be between 0 degree C and 63 degree C and
it defines the passive cooling temperature.
Below this temperature the fan stops in
the closed loop mode.
temp2_auto_point2_temp rw The low-temperature limit of the proportional
range. Below this temperature
pwm1 = pwm1_auto_point2_pwm. It can go from
0 degree C to 124 degree C in steps
of 4 degree C.
temp2_auto_point3_temp rw Above this temperature fan runs at maximum
speed. It can only have certain discrete
values which depend on temp2_auto_point2_temp
and pwm1_auto_point2_pwm. Read it out after
writing to get actual value.
Module parameters
-----------------
If your board has a BIOS that initializes the amc6821 correctly, you should
load the module with: init=0.
If your board BIOS doesn't initialize the chip, or you want
different settings, you can set the following parameters:
init=1,
pwminv: 0 default pwm output, 1 inverts pwm output.

296
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View File

@@ -0,0 +1,296 @@
Kernel driver asc7621
==================
Supported chips:
Andigilog aSC7621 and aSC7621a
Prefix: 'asc7621'
Addresses scanned: I2C 0x2c, 0x2d, 0x2e
Datasheet: http://www.fairview5.com/linux/asc7621/asc7621.pdf
Author:
George Joseph
Description provided by Dave Pivin @ Andigilog:
Andigilog has both the PECI and pre-PECI versions of the Heceta-6, as
Intel calls them. Heceta-6e has high frequency PWM and Heceta-6p has
added PECI and a 4th thermal zone. The Andigilog aSC7611 is the
Heceta-6e part and aSC7621 is the Heceta-6p part. They are both in
volume production, shipping to Intel and their subs.
We have enhanced both parts relative to the governing Intel
specification. First enhancement is temperature reading resolution. We
have used registers below 20h for vendor-specific functions in addition
to those in the Intel-specified vendor range.
Our conversion process produces a result that is reported as two bytes.
The fan speed control uses this finer value to produce a "step-less" fan
PWM output. These two bytes are "read-locked" to guarantee that once a
high or low byte is read, the other byte is locked-in until after the
next read of any register. So to get an atomic reading, read high or low
byte, then the very next read should be the opposite byte. Our data
sheet says 10-bits of resolution, although you may find the lower bits
are active, they are not necessarily reliable or useful externally. We
chose not to mask them.
We employ significant filtering that is user tunable as described in the
data sheet. Our temperature reports and fan PWM outputs are very smooth
when compared to the competition, in addition to the higher resolution
temperature reports. The smoother PWM output does not require user
intervention.
We offer GPIO features on the former VID pins. These are open-drain
outputs or inputs and may be used as general purpose I/O or as alarm
outputs that are based on temperature limits. These are in 19h and 1Ah.
We offer flexible mapping of temperature readings to thermal zones. Any
temperature may be mapped to any zone, which has a default assignment
that follows Intel's specs.
Since there is a fan to zone assignment that allows for the "hotter" of
a set of zones to control the PWM of an individual fan, but there is no
indication to the user, we have added an indicator that shows which zone
is currently controlling the PWM for a given fan. This is in register
00h.
Both remote diode temperature readings may be given an offset value such
that the reported reading as well as the temperature used to determine
PWM may be offset for system calibration purposes.
PECI Extended configuration allows for having more than two domains per
PECI address and also provides an enabling function for each PECI
address. One could use our flexible zone assignment to have a zone
assigned to up to 4 PECI addresses. This is not possible in the default
Intel configuration. This would be useful in multi-CPU systems with
individual fans on each that would benefit from individual fan control.
This is in register 0Eh.
The tachometer measurement system is flexible and able to adapt to many
fan types. We can also support pulse-stretched PWM so that 3-wire fans
may be used. These characteristics are in registers 04h to 07h.
Finally, we have added a tach disable function that turns off the tach
measurement system for individual tachs in order to save power. That is
in register 75h.
--
aSC7621 Product Description
The aSC7621 has a two wire digital interface compatible with SMBus 2.0.
Using a 10-bit ADC, the aSC7621 measures the temperature of two remote diode
connected transistors as well as its own die. Support for Platform
Environmental Control Interface (PECI) is included.
Using temperature information from these four zones, an automatic fan speed
control algorithm is employed to minimize acoustic impact while achieving
recommended CPU temperature under varying operational loads.
To set fan speed, the aSC7621 has three independent pulse width modulation
(PWM) outputs that are controlled by one, or a combination of three,
temperature zones. Both high- and low-frequency PWM ranges are supported.
The aSC7621 also includes a digital filter that can be invoked to smooth
temperature readings for better control of fan speed and minimum acoustic
impact.
The aSC7621 has tachometer inputs to measure fan speed on up to four fans.
Limit and status registers for all measured values are included to alert
the system host that any measurements are outside of programmed limits
via status registers.
System voltages of VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard power are
monitored efficiently with internal scaling resistors.
Features
- Supports PECI interface and monitors internal and remote thermal diodes
- 2-wire, SMBus 2.0 compliant, serial interface
- 10-bit ADC
- Monitors VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard/processor supplies
- Programmable autonomous fan control based on temperature readings
- Noise filtering of temperature reading for fan speed control
- 0.25C digital temperature sensor resolution
- 3 PWM fan speed control outputs for 2-, 3- or 4-wire fans and up to 4 fan
tachometer inputs
- Enhanced measured temperature to Temperature Zone assignment.
- Provides high and low PWM frequency ranges
- 3 GPIO pins for custom use
- 24-Lead QSOP package
Configuration Notes
===================
Except where noted below, the sysfs entries created by this driver follow
the standards defined in "sysfs-interface".
temp1_source
0 (default) peci_legacy = 0, Remote 1 Temperature
peci_legacy = 1, PECI Processor Temperature 0
1 Remote 1 Temperature
2 Remote 2 Temperature
3 Internal Temperature
4 PECI Processor Temperature 0
5 PECI Processor Temperature 1
6 PECI Processor Temperature 2
7 PECI Processor Temperature 3
temp2_source
0 (default) Internal Temperature
1 Remote 1 Temperature
2 Remote 2 Temperature
3 Internal Temperature
4 PECI Processor Temperature 0
5 PECI Processor Temperature 1
6 PECI Processor Temperature 2
7 PECI Processor Temperature 3
temp3_source
0 (default) Remote 2 Temperature
1 Remote 1 Temperature
2 Remote 2 Temperature
3 Internal Temperature
4 PECI Processor Temperature 0
5 PECI Processor Temperature 1
6 PECI Processor Temperature 2
7 PECI Processor Temperature 3
temp4_source
0 (default) peci_legacy = 0, PECI Processor Temperature 0
peci_legacy = 1, Remote 1 Temperature
1 Remote 1 Temperature
2 Remote 2 Temperature
3 Internal Temperature
4 PECI Processor Temperature 0
5 PECI Processor Temperature 1
6 PECI Processor Temperature 2
7 PECI Processor Temperature 3
temp[1-4]_smoothing_enable
temp[1-4]_smoothing_time
Smooths spikes in temp readings caused by noise.
Valid values in milliseconds are:
35000
17600
11800
7000
4400
3000
1600
800
temp[1-4]_crit
When the corresponding zone temperature reaches this value,
ALL pwm outputs will got to 100%.
temp[5-8]_input
temp[5-8]_enable
The aSC7621 can also read temperatures provided by the processor
via the PECI bus. Usually these are "core" temps and are relative
to the point where the automatic thermal control circuit starts
throttling. This means that these are usually negative numbers.
pwm[1-3]_enable
0 Fan off.
1 Fan on manual control.
2 Fan on automatic control and will run at the minimum pwm
if the temperature for the zone is below the minimum.
3 Fan on automatic control but will be off if the temperature
for the zone is below the minimum.
4-254 Ignored.
255 Fan on full.
pwm[1-3]_auto_channels
Bitmap as described in sysctl-interface with the following
exceptions...
Only the following combination of zones (and their corresponding masks)
are valid:
1
2
3
2,3
1,2,3
4
1,2,3,4
Special values:
0 Disabled.
16 Fan on manual control.
31 Fan on full.
pwm[1-3]_invert
When set, inverts the meaning of pwm[1-3].
i.e. when pwm = 0, the fan will be on full and
when pwm = 255 the fan will be off.
pwm[1-3]_freq
PWM frequency in Hz
Valid values in Hz are:
10
15
23
30 (default)
38
47
62
94
23000
24000
25000
26000
27000
28000
29000
30000
Setting any other value will be ignored.
peci_enable
Enables or disables PECI
peci_avg
Input filter average time.
0 0 Sec. (no Smoothing) (default)
1 0.25 Sec.
2 0.5 Sec.
3 1.0 Sec.
4 2.0 Sec.
5 4.0 Sec.
6 8.0 Sec.
7 0.0 Sec.
peci_legacy
0 Standard Mode (default)
Remote Diode 1 reading is associated with
Temperature Zone 1, PECI is associated with
Zone 4
1 Legacy Mode
PECI is associated with Temperature Zone 1,
Remote Diode 1 is associated with Zone 4
peci_diode
Diode filter
0 0.25 Sec.
1 1.1 Sec.
2 2.4 Sec. (default)
3 3.4 Sec.
4 5.0 Sec.
5 6.8 Sec.
6 10.2 Sec.
7 16.4 Sec.
peci_4domain
Four domain enable
0 1 or 2 Domains for enabled processors (default)
1 3 or 4 Domains for enabled processors
peci_domain
Domain
0 Processor contains a single domain (0) (default)
1 Processor contains two domains (0,1)

53
Documentation/hwmon/it87
View File

@@ -5,31 +5,23 @@ Supported chips:
* IT8705F
Prefix: 'it87'
Addresses scanned: from Super I/O config space (8 I/O ports)
Datasheet: Publicly available at the ITE website
http://www.ite.com.tw/product_info/file/pc/IT8705F_V.0.4.1.pdf
Datasheet: Once publicly available at the ITE website, but no longer
* IT8712F
Prefix: 'it8712'
Addresses scanned: from Super I/O config space (8 I/O ports)
Datasheet: Publicly available at the ITE website
http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.1.pdf
http://www.ite.com.tw/product_info/file/pc/Errata%20V0.1%20for%20IT8712F%20V0.9.1.pdf
http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.3.pdf
Datasheet: Once publicly available at the ITE website, but no longer
* IT8716F/IT8726F
Prefix: 'it8716'
Addresses scanned: from Super I/O config space (8 I/O ports)
Datasheet: Publicly available at the ITE website
http://www.ite.com.tw/product_info/file/pc/IT8716F_V0.3.ZIP
http://www.ite.com.tw/product_info/file/pc/IT8726F_V0.3.pdf
Datasheet: Once publicly available at the ITE website, but no longer
* IT8718F
Prefix: 'it8718'
Addresses scanned: from Super I/O config space (8 I/O ports)
Datasheet: Publicly available at the ITE website
http://www.ite.com.tw/product_info/file/pc/IT8718F_V0.2.zip
http://www.ite.com.tw/product_info/file/pc/IT8718F_V0%203_(for%20C%20version).zip
Datasheet: Once publicly available at the ITE website, but no longer
* IT8720F
Prefix: 'it8720'
Addresses scanned: from Super I/O config space (8 I/O ports)
Datasheet: Not yet publicly available.
Datasheet: Not publicly available
* SiS950 [clone of IT8705F]
Prefix: 'it87'
Addresses scanned: from Super I/O config space (8 I/O ports)
@@ -136,6 +128,10 @@ registers are read whenever any data is read (unless it is less than 1.5
seconds since the last update). This means that you can easily miss
once-only alarms.
Out-of-limit readings can also result in beeping, if the chip is properly
wired and configured. Beeping can be enabled or disabled per sensor type
(temperatures, voltages and fans.)
The IT87xx only updates its values each 1.5 seconds; reading it more often
will do no harm, but will return 'old' values.
@@ -150,11 +146,38 @@ Fan speed control
-----------------
The fan speed control features are limited to manual PWM mode. Automatic
"Smart Guardian" mode control handling is not implemented. However
if you want to go for "manual mode" just write 1 to pwmN_enable.
"Smart Guardian" mode control handling is only implemented for older chips
(see below.) However if you want to go for "manual mode" just write 1 to
pwmN_enable.
If you are only able to control the fan speed with very small PWM values,
try lowering the PWM base frequency (pwm1_freq). Depending on the fan,
it may give you a somewhat greater control range. The same frequency is
used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are
read-only.
Automatic fan speed control (old interface)
-------------------------------------------
The driver supports the old interface to automatic fan speed control
which is implemented by IT8705F chips up to revision F and IT8712F
chips up to revision G.
This interface implements 4 temperature vs. PWM output trip points.
The PWM output of trip point 4 is always the maximum value (fan running
at full speed) while the PWM output of the other 3 trip points can be
freely chosen. The temperature of all 4 trip points can be freely chosen.
Additionally, trip point 1 has an hysteresis temperature attached, to
prevent fast switching between fan on and off.
The chip automatically computes the PWM output value based on the input
temperature, based on this simple rule: if the temperature value is
between trip point N and trip point N+1 then the PWM output value is
the one of trip point N. The automatic control mode is less flexible
than the manual control mode, but it reacts faster, is more robust and
doesn't use CPU cycles.
Trip points must be set properly before switching to automatic fan speed
control mode. The driver will perform basic integrity checks before
actually switching to automatic control mode.

65
Documentation/hwmon/k10temp Normal file
View File

@@ -0,0 +1,65 @@
Kernel driver k10temp
=====================
Supported chips:
* AMD Family 10h processors:
Socket F: Quad-Core/Six-Core/Embedded Opteron (but see below)
Socket AM2+: Quad-Core Opteron, Phenom (II) X3/X4, Athlon X2 (but see below)
Socket AM3: Quad-Core Opteron, Athlon/Phenom II X2/X3/X4, Sempron II
Socket S1G3: Athlon II, Sempron, Turion II
* AMD Family 11h processors:
Socket S1G2: Athlon (X2), Sempron (X2), Turion X2 (Ultra)
Prefix: 'k10temp'
Addresses scanned: PCI space
Datasheets:
BIOS and Kernel Developer's Guide (BKDG) For AMD Family 10h Processors:
http://support.amd.com/us/Processor_TechDocs/31116.pdf
BIOS and Kernel Developer's Guide (BKDG) for AMD Family 11h Processors:
http://support.amd.com/us/Processor_TechDocs/41256.pdf
Revision Guide for AMD Family 10h Processors:
http://support.amd.com/us/Processor_TechDocs/41322.pdf
Revision Guide for AMD Family 11h Processors:
http://support.amd.com/us/Processor_TechDocs/41788.pdf
AMD Family 11h Processor Power and Thermal Data Sheet for Notebooks:
http://support.amd.com/us/Processor_TechDocs/43373.pdf
AMD Family 10h Server and Workstation Processor Power and Thermal Data Sheet:
http://support.amd.com/us/Processor_TechDocs/43374.pdf
AMD Family 10h Desktop Processor Power and Thermal Data Sheet:
http://support.amd.com/us/Processor_TechDocs/43375.pdf
Author: Clemens Ladisch <clemens@ladisch.de>
Description
-----------
This driver permits reading of the internal temperature sensor of AMD
Family 10h and 11h processors.
All these processors have a sensor, but on those for Socket F or AM2+,
the sensor may return inconsistent values (erratum 319). The driver
will refuse to load on these revisions unless you specify the "force=1"
module parameter.
Due to technical reasons, the driver can detect only the mainboard's
socket type, not the processor's actual capabilities. Therefore, if you
are using an AM3 processor on an AM2+ mainboard, you can safely use the
"force=1" parameter.
There is one temperature measurement value, available as temp1_input in
sysfs. It is measured in degrees Celsius with a resolution of 1/8th degree.
Please note that it is defined as a relative value; to quote the AMD manual:
Tctl is the processor temperature control value, used by the platform to
control cooling systems. Tctl is a non-physical temperature on an
arbitrary scale measured in degrees. It does _not_ represent an actual
physical temperature like die or case temperature. Instead, it specifies
the processor temperature relative to the point at which the system must
supply the maximum cooling for the processor's specified maximum case
temperature and maximum thermal power dissipation.
The maximum value for Tctl is available in the file temp1_max.
If the BIOS has enabled hardware temperature control, the threshold at
which the processor will throttle itself to avoid damage is available in
temp1_crit and temp1_crit_hyst.

55
Documentation/hwmon/lis3lv02d
View File

@@ -3,7 +3,8 @@ Kernel driver lis3lv02d
Supported chips:
* STMicroelectronics LIS3LV02DL and LIS3LV02DQ
* STMicroelectronics LIS3LV02DL, LIS3LV02DQ (12 bits precision)
* STMicroelectronics LIS302DL, LIS3L02DQ, LIS331DL (8 bits)
Authors:
Yan Burman <burman.yan@gmail.com>
@@ -13,32 +14,52 @@ Authors:
Description
-----------
This driver provides support for the accelerometer found in various HP
laptops sporting the feature officially called "HP Mobile Data
Protection System 3D" or "HP 3D DriveGuard". It detects automatically
laptops with this sensor. Known models (for now the HP 2133, nc6420,
nc2510, nc8510, nc84x0, nw9440 and nx9420) will have their axis
automatically oriented on standard way (eg: you can directly play
neverball). The accelerometer data is readable via
/sys/devices/platform/lis3lv02d.
This driver provides support for the accelerometer found in various HP laptops
sporting the feature officially called "HP Mobile Data Protection System 3D" or
"HP 3D DriveGuard". It detects automatically laptops with this sensor. Known
models (full list can be found in drivers/hwmon/hp_accel.c) will have their
axis automatically oriented on standard way (eg: you can directly play
neverball). The accelerometer data is readable via
/sys/devices/platform/lis3lv02d. Reported values are scaled
to mg values (1/1000th of earth gravity).
Sysfs attributes under /sys/devices/platform/lis3lv02d/:
position - 3D position that the accelerometer reports. Format: "(x,y,z)"
calibrate - read: values (x, y, z) that are used as the base for input
class device operation.
write: forces the base to be recalibrated with the current
position.
rate - reports the sampling rate of the accelerometer device in HZ
rate - read reports the sampling rate of the accelerometer device in HZ.
write changes sampling rate of the accelerometer device.
Only values which are supported by HW are accepted.
selftest - performs selftest for the chip as specified by chip manufacturer.
This driver also provides an absolute input class device, allowing
the laptop to act as a pinball machine-esque joystick.
the laptop to act as a pinball machine-esque joystick. Joystick device can be
calibrated. Joystick device can be in two different modes.
By default output values are scaled between -32768 .. 32767. In joystick raw
mode, joystick and sysfs position entry have the same scale. There can be
small difference due to input system fuzziness feature.
Events are also available as input event device.
Selftest is meant only for hardware diagnostic purposes. It is not meant to be
used during normal operations. Position data is not corrupted during selftest
but interrupt behaviour is not guaranteed to work reliably. In test mode, the
sensing element is internally moved little bit. Selftest measures difference
between normal mode and test mode. Chip specifications tell the acceptance
limit for each type of the chip. Limits are provided via platform data
to allow adjustment of the limits without a change to the actual driver.
Seltest returns either "OK x y z" or "FAIL x y z" where x, y and z are
measured difference between modes. Axes are not remapped in selftest mode.
Measurement values are provided to help HW diagnostic applications to make
final decision.
On HP laptops, if the led infrastructure is activated, support for a led
indicating disk protection will be provided as /sys/class/leds/hp::hddprotect.
Another feature of the driver is misc device called "freefall" that
acts similar to /dev/rtc and reacts on free-fall interrupts received
from the device. It supports blocking operations, poll/select and
fasync operation modes. You must read 1 bytes from the device. The
result is number of free-fall interrupts since the last successful
read (or 255 if number of interrupts would not fit).
read (or 255 if number of interrupts would not fit). See the hpfall.c
file for an example on using the device.
Axes orientation
@@ -55,7 +76,7 @@ the accelerometer are converted into a "standard" organisation of the axes
* If the laptop is put upside-down, Z becomes negative
If your laptop model is not recognized (cf "dmesg"), you can send an
email to the authors to add it to the database. When reporting a new
email to the maintainer to add it to the database. When reporting a new
laptop, please include the output of "dmidecode" plus the value of
/sys/devices/platform/lis3lv02d/position in these four cases.

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