The refcount is checked only in tty_unregister_ldisc and EBUSY returned
if it is nonzero. But none of the tty_unregister_ldisc callers act
anyhow if this (or any other) error is returned. So remove
tty_ldisc_ops::refcount completely and make tty_unregister_ldisc return
'void' in the next patches. That means we assume tty_unregister_ldisc is
not called while the ldisc might be in use. That relies on
try_module_get in get_ldops and module_put in put_ldops.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-18-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Group the ctrl members under a single struct called ctrl. The new struct
contains 'pgrp', 'session', 'pktstatus', and 'packet'. 'pktstatus' and
'packet' used to be bits in a bitfield. The struct also contains the
lock protecting them to share the same cache line.
Note that commit c545b66c69 (tty: Serialize tcflow() with other tty
flow control changes) added a padding to the original bitfield. It was
for the bitfield to occupy a whole 64b word to avoid interferring stores
on Alpha (cannot we evaporate this arch with weird implications to C
code yet?). But it doesn't work as expected as the padding
(tty_struct::ctrl_unused) is aligned to a 8B boundary too and occupies
some bytes from the next word.
So make it reliable by:
1) setting __aligned of the struct -- that aligns the start, and
2) making 'unsigned long unused[0]' as the last member of the struct --
pads the end.
Add a kerneldoc comment for this grouped members.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20210505091928.22010-14-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Group the flow flags under a single struct called flow. The new struct
contains 'stopped' and 'tco_stopped' bools which used to be bits in a
bitfield. The struct also contains the lock protecting them to
potentially share the same cache line.
Note that commit c545b66c69 (tty: Serialize tcflow() with other tty
flow control changes) added a padding to the original bitfield. It was
for the bitfield to occupy a whole 64b word to avoid interferring stores
on Alpha (cannot we evaporate this arch with weird implications to C
code yet?). But it doesn't work as expected as the padding
(tty_struct::unused) is aligned to a 8B boundary too and occupies some
bytes from the next word.
So make it reliable by:
1) setting __aligned of the struct -- that aligns the start, and
2) making 'unsigned long unused[0]' as the last member of the struct --
pads the end.
This is also the perfect time to start the documentation of tty_struct
where all this lives. So we start by documenting what these bools
actually serve for. And why we do all the alignment dances. Only the few
up-to-date information from the Theodore's comment made it into this new
Kerneldoc comment.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/20210505091928.22010-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Handle !TTY_NORMAL as a short path and 'continue' the loop. Do the rest as
a normal code flow. This decreases the indentation level by one and
makes the code flow more understandable.
IOW, we avoid
if (cond) {
LONG CODE;
} else
single_line();
by
if (!cond) {
single_line();
continue;
}
LONG CODE;
While at it, invert also the 'if (!test_bit) A else B' into 'if
(test_bit) B else A'.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-10-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move lnext handling from __receive_buf to n_tty_receive_buf_standard. It
simplifies the handling as it needs not fetching 'flag' and decrement
'count' in __receive_buf. Instead, all this is left up to the loop in
n_tty_receive_buf_standard which already does that.
This way, no need to repeat the action when n_tty_receive_char_special
returns true -- ldata->lnext is set there in that case, so the 'if
(ldata->lnext)' check is sufficient. The next patch will switch
n_tty_receive_char_special to return 'void'.
The result is much simplified code flow.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After the previous patches, n_tty_receive_buf_standard and
n_tty_receive_buf_fast differ only in handling of tty line and input
controls. Unlike n_tty_receive_buf_fast, n_tty_receive_buf_standard
handles them all (I_ISTRIP, I_IUCLC, L_IEXTEN, L_EXTPROC, and I_PARMRK).
So remove n_tty_receive_buf_fast and let n_tty_receive_buf_standard do
the handling. Actually most of the tests are only moved from
__receive_buf to n_tty_receive_buf_standard.
Again, the code duplication is not worth the theoretical speedup.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_tty_receive_char_fast is a copy of n_tty_receive_char with one
exception: PARMRK is not doubled in the former. Unify these two and
double PARMRK depending on a newly added parameter (bool parmrk_dbl).
I don't think the theoretical speedup is worth the code duplication.
Which is directly connected with maintenance burden.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wrapper was meant as an optimization in commits eb3e4668bd (n_tty:
Un-inline slow-path n_tty_receive_char()) and e60d27c4d8 (n_tty:
Factor LNEXT processing from per-char i/o path). But the current
compiler (gcc 10) inlines it anyway (as expected). Actually, I'm not
sure it ever didn't. It would need to be marked with the noinline
attribute.
So remove this useless wrapper.
And if we ever introduce something similar, we need confirming numbers
first.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Noone stepped up in the past two years since it was marked as BROKEN by
commit c7084edc3f (tty: mark Siemens R3964 line discipline as BROKEN).
Remove the line discipline for good.
Three remarks:
* we remove also the uapi header (as noone is able to use that interface
anyway)
* we do *not* remove the N_R3964 constant definition from tty.h, so it
remains reserved.
* in_interrupt() check is now removed from vt's con_put_char. Noone else
calls tty_operations::put_char from interrupt context.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Our SoC's have always had a NS16650A UART core and older SoC's would
have a compatible string of: 'compatible = ""ns16550a"' and use the
8250_of driver. Our newer SoC's have added enhancements to the base
core to add support for DMA and accurate high speed baud rates and use
this newer 8250_bcm7271 driver. The Device Tree node for our enhanced
UARTs has a compatible string of: 'compatible = "brcm,bcm7271-uart",
"ns16550a"''. With both drivers running and the link order setup so
that the 8250_bcm7217 driver is initialized before the 8250_of driver,
we should bind the 8250_bcm7271 driver to the enhanced UART, or for
upstream kernels that don't have the 8250_bcm7271 driver, we bind to
the 8250_of driver.
The problem is that when both the 8250_of and 8250_bcm7271 drivers
were running, occasionally the 8250_of driver would be bound to the
enhanced UART instead of the 8250_bcm7271 driver. This was happening
because we use SCMI based clocks which come up late in initialization
and cause probe DEFER's when the two drivers get their clocks.
Occasionally the SCMI clock would become ready between the 8250_bcm7271
probe and the 8250_of probe and the 8250_of driver would be bound. To
fix this we decided to config only our 8250_bcm7271 driver and added
"ns16665a0" to the compatible string so the driver would work on our
older system.
This commit has of_platform_serial_probe() check specifically for the
"brcm,bcm7271-uart" and whether its companion driver is enabled. If it
is the case, and the clock provider is not ready, we want to make sure
that when the 8250_bcm7271.c driver returns EPROBE_DEFER, we are not
getting the UART registered via 8250_of.c.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210423183206.3917725-1-f.fainelli@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When there is more than one serial port present, the property 'label'
allows a custom name to be used for briefly describe the usage or position
of each serial port.
Without this "label" property, many dtbs_check warnings similar to the
following are reported:
arch/arm64/boot/dts/hisilicon/hi3660-hikey960.dt.yaml: \
serial@ffd74000: Additional properties are not allowed ('label' was unexpected)
From schema: Documentation/devicetree/bindings/serial/pl011.yaml
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210506132049.1513-3-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Previously this driver's use of devm_ioremap_resource() led to
duplicated calls to __release_region() when unbinding it (one from
serial8250_release_std_resource() and one from devres_release_all()),
the second of which resulted in a warning message:
# echo 1e787000.serial > /sys/bus/platform/drivers/aspeed-vuart/unbind
[33091.774200] Trying to free nonexistent resource <000000001e787000-000000001e78703f>
With this change the driver uses the generic serial8250 code's
UPF_IOREMAP to take care of the register mapping automatically instead
of doing its own devm_ioremap_resource(), thus avoiding the duplicate
__release_region() on unbind.
In doing this we eliminate vuart->regs, since it merely duplicates
vuart->port->port.membase, which we now use for our I/O accesses.
Reported-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210510014231.647-4-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Previously this had only been initialized if we hit the throttling path
in aspeed_vuart_handle_irq(); moving it to the probe function is a
slight consistency improvement and avoids redundant reinitialization in
the interrupt handler. It also serves as preparation for converting the
driver's I/O accesses to use port->port.membase instead of its own
vuart->regs.
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210510014231.647-3-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SYSRQ doesn't work with DMA. This is because there is no error
indication whether a symbol had a framing error or not. Actually,
this is not completely correct, there is a bit in the data register
which is set in this case, but we'd have to read change the DMA access
to 16 bit and we'd need to post process the data, thus make the DMA
pointless in the first place.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-10-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The LPUART doesn't have the ability to control the RTS or CTS line
manually. Instead it will set it automatically when data is send or
handle it when data is received. Thus drop the wrong code in set_mctrl.
For the 32 bit version this was already done in the commit 2b30efe2e8
("tty: serial: lpuart: Remove unnecessary code from set_mctrl"). Keep
the 8-bit version in sync and remove it there, too.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-8-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wrong code in set_mctrl() was already removed in commit 2b30efe2e8
("tty: serial: lpuart: Remove unnecessary code from set_mctrl"), but the
code in get_mctrl() wasn't removed. It will not return the state of the
RTS or CTS line but whether automatic flow control is enabled, which is
wrong for the get_mctrl(). Thus remove it.
Fixes: 2b30efe2e8 ("tty: serial: lpuart: Remove unnecessary code from set_mctrl")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-7-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>From commit 75f4e830fa ("serial: do not restore interrupt state in
sysrq helper"):
Since commit 81e2073c17 ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly
requested as threaded are always called with interrupts disabled and
there is no need to save the interrupt state when taking the port
lock.
Apply this also to fsl_lpuart in prepartion for sysrq handling with
uart_unlock_and_check_sysrq().
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-4-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should be very careful about the register values that will be used
for division or modulo operations, althrough the possibility that the
UARTBAUD register value is zero is very low, but we had better to deal
with the "bad data" of hardware in advance to avoid division or modulo
by zero leading to undefined kernel behavior.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20210427021226.27468-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit b9d79e4ca4 ("fbmem: Mark proc_fb_seq_ops as __maybe_unused")
places the '__maybe_unused' in an entirely incorrect location between
the "struct" keyword and the structure name.
It's a wonder that gcc accepts that silently, but clang quite reasonably
warns about it:
drivers/video/fbdev/core/fbmem.c:736:21: warning: attribute declaration must precede definition [-Wignored-attributes]
static const struct __maybe_unused seq_operations proc_fb_seq_ops = {
^
Fix it.
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull drm fixes from Dave Airlie:
"Bit later than usual, I queued them all up on Friday then promptly
forgot to write the pull request email. This is mainly amdgpu fixes,
with some radeon/msm/fbdev and one i915 gvt fix thrown in.
amdgpu:
- MPO hang workaround
- Fix for concurrent VM flushes on vega/navi
- dcefclk is not adjustable on navi1x and newer
- MST HPD debugfs fix
- Suspend/resumes fixes
- Register VGA clients late in case driver fails to load
- Fix GEM leak in user framebuffer create
- Add support for polaris12 with 32 bit memory interface
- Fix duplicate cursor issue when using overlay
- Fix corruption with tiled surfaces on VCN3
- Add BO size and stride check to fix BO size verification
radeon:
- Fix off-by-one in power state parsing
- Fix possible memory leak in power state parsing
msm:
- NULL ptr dereference fix
fbdev:
- procfs disabled warning fix
i915:
- gvt: Fix a possible division by zero in vgpu display rate
calculation"
* tag 'drm-next-2021-05-10' of git://anongit.freedesktop.org/drm/drm:
drm/amdgpu: Use device specific BO size & stride check.
drm/amdgpu: Init GFX10_ADDR_CONFIG for VCN v3 in DPG mode.
drm/amd/pm: initialize variable
drm/radeon: Avoid power table parsing memory leaks
drm/radeon: Fix off-by-one power_state index heap overwrite
drm/amd/display: Fix two cursor duplication when using overlay
drm/amdgpu: add new MC firmware for Polaris12 32bit ASIC
fbmem: Mark proc_fb_seq_ops as __maybe_unused
drm/msm/dpu: Delete bonkers code
drm/i915/gvt: Prevent divided by zero when calculating refresh rate
amdgpu: fix GEM obj leak in amdgpu_display_user_framebuffer_create
drm/amdgpu: Register VGA clients after init can no longer fail
drm/amdgpu: Handling of amdgpu_device_resume return value for graceful teardown
drm/amdgpu: fix r initial values
drm/amd/display: fix wrong statement in mst hpd debugfs
amdgpu/pm: set pp_dpm_dcefclk to readonly on NAVI10 and newer gpus
amdgpu/pm: Prevent force of DCEFCLK on NAVI10 and SIENNA_CICHLID
drm/amdgpu: fix concurrent VM flushes on Vega/Navi v2
drm/amd/display: Reject non-zero src_y and src_x for video planes
Pull block fix from Jens Axboe:
"Turns out the bio max size change still has issues, so let's get it
reverted for 5.13-rc1. We'll shake out the issues there and defer it
to 5.14 instead"
* tag 'block-5.13-2021-05-09' of git://git.kernel.dk/linux-block:
Revert "bio: limit bio max size"
Pull cifs fixes from Steve French:
"Three small SMB3 chmultichannel related changesets (also for stable)
from the SMB3 test event this week.
The other fixes are still in review/testing"
* tag '5.13-rc-smb3-part3' of git://git.samba.org/sfrench/cifs-2.6:
smb3: if max_channels set to more than one channel request multichannel
smb3: do not attempt multichannel to server which does not support it
smb3: when mounting with multichannel include it in requested capabilities
Pull scheduler fixes from Thomas Gleixner:
"A set of scheduler updates:
- Prevent PSI state corruption when schedule() races with cgroup
move.
A recent commit combined two PSI callbacks to reduce the number of
cgroup tree updates, but missed that schedule() can drop rq::lock
for load balancing, which opens the race window for
cgroup_move_task() which then observes half updated state.
The fix is to solely use task::ps_flags instead of looking at the
potentially mismatching scheduler state
- Prevent an out-of-bounds access in uclamp caused bu a rounding
division which can lead to an off-by-one error exceeding the
buckets array size.
- Prevent unfairness caused by missing load decay when a task is
attached to a cfs runqueue.
The old load of the task was attached to the runqueue and never
removed. Fix it by enforcing the load update through the hierarchy
for unthrottled run queue instances.
- A documentation fix fot the 'sched_verbose' command line option"
* tag 'sched-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Fix unfairness caused by missing load decay
sched: Fix out-of-bound access in uclamp
psi: Fix psi state corruption when schedule() races with cgroup move
sched,doc: sched_debug_verbose cmdline should be sched_verbose
Pull locking fixes from Thomas Gleixner:
"A set of locking related fixes and updates:
- Two fixes for the futex syscall related to the timeout handling.
FUTEX_LOCK_PI does not support the FUTEX_CLOCK_REALTIME bit and
because it's not set the time namespace adjustment for clock
MONOTONIC is applied wrongly.
FUTEX_WAIT cannot support the FUTEX_CLOCK_REALTIME bit because its
always a relative timeout.
- Cleanups in the futex syscall entry points which became obvious
when the two timeout handling bugs were fixed.
- Cleanup of queued_write_lock_slowpath() as suggested by Linus
- Fixup of the smp_call_function_single_async() prototype"
* tag 'locking-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Make syscall entry points less convoluted
futex: Get rid of the val2 conditional dance
futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI
Revert 337f13046f ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op")
locking/qrwlock: Cleanup queued_write_lock_slowpath()
smp: Fix smp_call_function_single_async prototype
