Preemption must be disabled before entering a sequence count write side
critical section. Failing to do so, the seqcount read side can preempt
the write side section and spin for the entire scheduler tick. If that
reader belongs to a real-time scheduling class, it can spin forever and
the kernel will livelock.
Assert through lockdep that preemption is disabled for seqcount writers.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-9-a.darwish@linutronix.de
Asserting that preemption is enabled or disabled is a critical sanity
check. Developers are usually reluctant to add such a check in a
fastpath as reading the preemption count can be costly.
Extend the lockdep API with macros asserting that preemption is disabled
or enabled. If lockdep is disabled, or if the underlying architecture
does not support kernel preemption, this assert has no runtime overhead.
References: f54bb2ec02 ("locking/lockdep: Add IRQs disabled/enabled assertion APIs: ...")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-8-a.darwish@linutronix.de
raw_seqcount_begin() has the same code as raw_read_seqcount(), with the
exception of masking the sequence counter's LSB before returning it to
the caller.
Note, raw_seqcount_begin() masks the counter's LSB before returning it
to the caller so that read_seqcount_retry() can fail if the counter is
odd -- without the overhead of an extra branching instruction.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-7-a.darwish@linutronix.de
The seqlock.h seqcount_t and seqlock_t API definitions are presented in
the chronological order of their development rather than the order that
makes most sense to readers. This makes it hard to follow and understand
the header file code.
Group and reorder all of the exported seqlock.h functions according to
their function.
First, group together the seqcount_t standard read path functions:
- __read_seqcount_begin()
- raw_read_seqcount_begin()
- read_seqcount_begin()
since each function is implemented exactly in terms of the one above
it. Then, group the special-case seqcount_t readers on their own as:
- raw_read_seqcount()
- raw_seqcount_begin()
since the only difference between the two functions is that the second
one masks the sequence counter LSB while the first one does not. Note
that raw_seqcount_begin() can actually be implemented in terms of
raw_read_seqcount(), which will be done in a follow-up commit.
Then, group the seqcount_t write path functions, instead of injecting
unrelated seqcount_t latch functions between them, and order them as:
- raw_write_seqcount_begin()
- raw_write_seqcount_end()
- write_seqcount_begin_nested()
- write_seqcount_begin()
- write_seqcount_end()
- raw_write_seqcount_barrier()
- write_seqcount_invalidate()
which is the expected natural order. This also isolates the seqcount_t
latch functions into their own area, at the end of the sequence counters
section, and before jumping to the next one: sequential locks
(seqlock_t).
Do a similar grouping and reordering for seqlock_t "locking" readers vs.
the "conditionally locking or lockless" ones.
No implementation code was changed in any of the reordering above.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-5-a.darwish@linutronix.de
The seqcount_t latch reader example at the raw_write_seqcount_latch()
kernel-doc comment ends the latch read section with a manual smp memory
barrier and sequence counter comparison.
This is technically correct, but it is suboptimal: read_seqcount_retry()
already contains the same logic of an smp memory barrier and sequence
counter comparison.
End the latch read critical section example with read_seqcount_retry().
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-4-a.darwish@linutronix.de
Proper documentation for the design and usage of sequence counters and
sequential locks does not exist. Complete the seqlock.h documentation as
follows:
- Divide all documentation on a seqcount_t vs. seqlock_t basis. The
description for both mechanisms was intermingled, which is incorrect
since the usage constrains for each type are vastly different.
- Add an introductory paragraph describing the internal design of, and
rationale for, sequence counters.
- Document seqcount_t writer non-preemptibility requirement, which was
not previously documented anywhere, and provide a clear rationale.
- Provide template code for seqcount_t and seqlock_t initialization
and reader/writer critical sections.
- Recommend using seqlock_t by default. It implicitly handles the
serialization and non-preemptibility requirements of writers.
At seqlock.h:
- Remove references to brlocks as they've long been removed from the
kernel.
- Remove references to gcc-3.x since the kernel's minimum supported
gcc version is 4.9.
References: 0f6ed63b17 ("no need to keep brlock macros anymore...")
References: 6ec4476ac8 ("Raise gcc version requirement to 4.9")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-2-a.darwish@linutronix.de
This patch breaks a header loop involving qspinlock_types.h.
The issue is that qspinlock_types.h includes atomic.h, which then
eventually includes kernel.h which could lead back to the original
file via spinlock_types.h.
As ATOMIC_INIT is now defined by linux/types.h, there is no longer
any need to include atomic.h from qspinlock_types.h. This also
allows the CONFIG_PARAVIRT hack to be removed since it was trying
to prevent exactly this loop.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20200729123316.GC7047@gondor.apana.org.au
Some architectures may have special memory regions, within the given
memory range, which can't be used for the buffer in a kexec segment.
Implement weak arch_kexec_locate_mem_hole() definition which arch code
may override, to take care of special regions, while trying to locate
a memory hole.
Also, add the missing declarations for arch overridable functions and
and drop the __weak descriptors in the declarations to avoid non-weak
definitions from becoming weak.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602273603.575379.17665852963340380839.stgit@hbathini
Introduce a mechanism that performs an handshake between the userspace
provider and kernel driver which verifies that the user supports all
required features in order to operate correctly.
The handshake verifies the needed functionality by comparing the reported
device caps and the provider caps. If the device reports a non-zero
capability the appropriate comp mask is required from the userspace
provider in order to allocate the context.
Link: https://lore.kernel.org/r/20200722140312.3651-4-galpress@amazon.com
Reviewed-by: Shadi Ammouri <sammouri@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Peter writes:
ENDIAN issue fix and one query controller role API is introduced.
* tag 'usb-ci-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb:
usb: chipidea: imx: get available runtime dr mode for wakeup setting
usb: chipidea: add query_available_role interface
Documentation: ABI: usb: chipidea: Update Li Jun's e-mail
usb: chipidea: udc: fix the ENDIAN issue
RT tasks by default run at the highest capacity/performance level. When
uclamp is selected this default behavior is retained by enforcing the
requested uclamp.min (p->uclamp_req[UCLAMP_MIN]) of the RT tasks to be
uclamp_none(UCLAMP_MAX), which is SCHED_CAPACITY_SCALE; the maximum
value.
This is also referred to as 'the default boost value of RT tasks'.
See commit 1a00d99997 ("sched/uclamp: Set default clamps for RT tasks").
On battery powered devices, it is desired to control this default
(currently hardcoded) behavior at runtime to reduce energy consumed by
RT tasks.
For example, a mobile device manufacturer where big.LITTLE architecture
is dominant, the performance of the little cores varies across SoCs, and
on high end ones the big cores could be too power hungry.
Given the diversity of SoCs, the new knob allows manufactures to tune
the best performance/power for RT tasks for the particular hardware they
run on.
They could opt to further tune the value when the user selects
a different power saving mode or when the device is actively charging.
The runtime aspect of it further helps in creating a single kernel image
that can be run on multiple devices that require different tuning.
Keep in mind that a lot of RT tasks in the system are created by the
kernel. On Android for instance I can see over 50 RT tasks, only
a handful of which created by the Android framework.
To control the default behavior globally by system admins and device
integrator, introduce the new sysctl_sched_uclamp_util_min_rt_default
to change the default boost value of the RT tasks.
I anticipate this to be mostly in the form of modifying the init script
of a particular device.
To avoid polluting the fast path with unnecessary code, the approach
taken is to synchronously do the update by traversing all the existing
tasks in the system. This could race with a concurrent fork(), which is
dealt with by introducing sched_post_fork() function which will ensure
the racy fork will get the right update applied.
Tested on Juno-r2 in combination with the RT capacity awareness [1].
By default an RT task will go to the highest capacity CPU and run at the
maximum frequency, which is particularly energy inefficient on high end
mobile devices because the biggest core[s] are 'huge' and power hungry.
With this patch the RT task can be controlled to run anywhere by
default, and doesn't cause the frequency to be maximum all the time.
Yet any task that really needs to be boosted can easily escape this
default behavior by modifying its requested uclamp.min value
(p->uclamp_req[UCLAMP_MIN]) via sched_setattr() syscall.
[1] 804d402fb6: ("sched/rt: Make RT capacity-aware")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200716110347.19553-2-qais.yousef@arm.com
Add passthru command handling capability for the NVMeOF target and
export passthru APIs which are used to integrate passthru
code with nvmet-core.
The new file passthru.c handles passthru cmd parsing and execution.
In the passthru mode, we create a block layer request from the nvmet
request and map the data on to the block layer request.
Admin commands and features are on an allow list as there are a number
of each that don't make too much sense with passthrough. We use an
allow list such that new commands can be considered before being blindly
passed through. In both cases, vendor specific commands are always
allowed.
We also reject reservation IO commands as the underlying device cannot
differentiate between multiple hosts behind a fabric.
Based-on-a-patch-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
* drm: fix possible use-after-free
* dbi: fix SPI Type 1 transfer
* drm_fb_helper: use memcpy_io on bochs' sparc64
* mcde: fix stability
* panel: fix display noise on auo,kd101n80-45na
* panel: delay HPD checks for boe_nv133fhm_n61
* bridge: drop connector check in nwl-dsi bridge
* bridge: set proper bridge type for adv7511
* of: fix a double free
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200728110446.GA8076@linux-uq9g
This patch implements the tmr_notify callback for tcmu. When the callback
is called, tcmu checks the list of aborted commands it received as
parameter:
- aborted commands in the qfull_queue are removed from the queue and
target_complete_command is called
- from the cmd_ids of aborted commands currently uncompleted in cmd ring
it creates a list of aborted cmd_ids.
Finally a TMR notification is written to cmd ring containing TMR type and
cmd_id list. If there is no space in ring, the TMR notification is queued
on a TMR specific queue.
The TMR specific queue 'tmr_queue' can be seen as a extension of the cmd
ring. At the end of each iexecution of tcmu_complete_commands() we check
whether tmr_queue contains TMRs and try to move them onto the ring. If
tmr_queue is not empty after that, we don't call run_qfull_queue() because
commands must not overtake TMRs.
This way we guarantee that cmd_ids in TMR notification received by
userspace either match an active, not yet completed command or are no
longer valid due to userspace having complete some cmd_ids meanwhile.
New commands that were assigned to an aborted cmd_id will always appear on
the cmd ring _after_ the TMR.
Link: https://lore.kernel.org/r/20200726153510.13077-8-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
iscsi_target_sk_data_ready() could be invoked indirectly by
iscsi_target_do_login_rx() from the workqueue like this:
iscsi_target_do_login_rx()
iscsi_target_do_login()
iscsi_target_do_tx_login_io()
iscsit_put_login_tx()
iscsi_login_tx_data()
tx_data()
sock_sendmsg_nosec()
tcp_sendmsg()
release_sock()
sk_backlog_rcv()
tcp_v4_do_rcv()
tcp_data_ready()
iscsi_target_sk_data_ready()
At that time LOGIN_FLAGS_READ_ACTIVE is not cleared and
iscsi_target_sk_data_ready will not read data from the socket. Some iscsi
initiators (libiscsi) will wait forever for a reply.
LOGIN_FLAGS_READ_ACTIVE should be cleared early just after doing the
receive and before writing to the socket in iscsi_target_do_login_rx.
Unfortunately, LOGIN_FLAGS_READ_ACTIVE is also used by sk_state_change to
do login cleanup if a socket was closed at login time. It is supposed to be
cleared after the login PDU is successfully processed and replied.
Introduce another flag, LOGIN_FLAGS_WRITE_ACTIVE, to cover the transmit
part.
Link: https://lore.kernel.org/r/20200716100212.4237-2-houpu@bytedance.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Hou Pu <houpu@bytedance.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This avoids another inderect call per RX packet which save us around
20-40 ns.
Changelog:
v1 -> v2:
- Move declaraions to fib_rules.h to remove warnings
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch restores the RCU marking on bucket_table->buckets as
it really does need RCU protection. Its removal had led to a fatal
bug.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The rcu_dereference call in rht_ptr_rcu is completely bogus because
we've already dereferenced the value in __rht_ptr and operated on it.
This causes potential double readings which could be fatal. The RCU
dereference must occur prior to the comparison in __rht_ptr.
This patch changes the order of RCU dereference so that it is done
first and the result is then fed to __rht_ptr. The RCU marking
changes have been minimised using casts which will be removed in
a follow-up patch.
Fixes: ba6306e3f6 ("rhashtable: Remove RCU marking from...")
Reported-by: "Gong, Sishuai" <sishuai@purdue.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The pldmfw library is used to implement common logic needed to flash
devices based on firmware files using the format described by the PLDM
for Firmware Update standard.
This library consists of logic to parse the PLDM file format from
a firmware file object, as well as common logic for sending the relevant
PLDM header data to the device firmware.
A simple ops table is provided so that device drivers can implement
device specific hardware interactions while keeping the common logic to
the pldmfw library.
This library will be used by the Intel ice networking driver as part of
implementing device flash update via devlink. The library aims to be
vendor and device agnostic. For this reason, it has been placed in
lib/pldmfw, in the hopes that other devices which use the PLDM firmware
file format may benefit from it in the future. However, do note that not
all features defined in the PLDM standard have been implemented.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So the parser can be used to parse range property of ISA bus.
As they're all using PCI-like method of range property, there is no need
start a new parser.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Make sure not just the pointer itself but the whole range lies in
the user address space. For that pass the length and then use
the access_ok helper to do the check.
Fixes: 6d04fe15f7 ("net: optimize the sockptr_t for unified kernel/user address spaces")
Reported-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
sockptr_advance never properly worked. Replace it with _offset variants
of copy_from_sockptr and copy_to_sockptr.
Fixes: ba423fdaa5 ("net: add a new sockptr_t type")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While the kernel in general is not strict aliasing safe we can trivially
do that in sockptr_is_null without affecting code generation, so always
check the actually assigned union member.
Reported-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
When setting the PF interface up/down, notify the firmware to update
uplink state via MODIFY_VPORT_STATE, when E-Switch is enabled.
This behavior will prevent sending traffic out on uplink port when PF is
down, such as sending traffic from a VF interface which is still up.
Currently when calling mlx5e_open/close(), the driver only sends PAOS
command to notify the firmware to set the physical port state to
up/down, however, it is not sufficient. When VF is in "auto" state, it
follows the uplink state, which was not updated on mlx5e_open/close()
before this patch.
When switchdev mode is enabled and uplink representor is first enabled,
set the uplink port state value back to its FW default "AUTO".
Fixes: 63bfd399de ("net/mlx5e: Send PAOS command on interface up/down")
Signed-off-by: Ron Diskin <rondi@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Currently migrate_vma_setup() calls mmu_notifier_invalidate_range_start()
which flushes all device private page mappings whether or not a page is
being migrated to/from device private memory.
In order to not disrupt device mappings that are not being migrated, shift
the responsibility for clearing device private mappings to the device
driver and leave CPU page table unmapping handled by
migrate_vma_setup().
To support this, the caller of migrate_vma_setup() should always set
struct migrate_vma::pgmap_owner to a non NULL value that matches the
device private page->pgmap->owner. This value is then passed to the struct
mmu_notifier_range with a new event type which the driver's invalidation
function can use to avoid device MMU invalidations.
Link: https://lore.kernel.org/r/20200723223004.9586-4-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The src_owner field in struct migrate_vma is being used for two purposes,
it acts as a selection filter for which types of pages are to be migrated
and it identifies device private pages owned by the caller.
Split this into separate parameters so the src_owner field can be used
just to identify device private pages owned by the caller of
migrate_vma_setup().
Rename the src_owner field to pgmap_owner to reflect it is now used only
to identify which device private pages to migrate.
Link: https://lore.kernel.org/r/20200723223004.9586-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Pull asm-generic bugfix from Arnd Bergmann:
"A single bugfix for a regression introduced through a typo in the v5.8
merge window, leading to incorrect data returned from inl() on some
architectures"
* tag 'asm-generic-fixes-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
io: Fix return type of _inb and _inl
No need to define typedefs for the callbacks, because there is not a
single user except blk_mq_ops.
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Johan writes:
USB-serial updates for 5.9-rc1
Here are the USB-serial updates for 5.9-rc1, including:
- console flow-control support
- simulated line-breaks on some ch341
- hardware flow-control fixes for cp210x
- break-detection and sysrq fixes for ftdi_sio
- sysrq optimisations
- input parity checking for cp210x
Included are also some new device ids and various clean ups.
All have been in linux-next with no reported issues.
* tag 'usb-serial-5.9-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial: (31 commits)
USB: serial: qcserial: add EM7305 QDL product ID
USB: serial: iuu_phoenix: fix led-activity helpers
USB: serial: sierra: clean up special-interface handling
USB: serial: cp210x: use in-kernel types in port data
USB: serial: cp210x: drop unnecessary packed attributes
USB: serial: cp210x: add support for TIOCGICOUNT
USB: serial: cp210x: add support for line-status events
USB: serial: cp210x: disable interface on errors in open
USB: serial: drop redundant transfer-buffer casts
USB: serial: drop extern keyword from function declarations
USB: serial: drop unnecessary sysrq include
USB: serial: add sysrq break-handler dummy
USB: serial: inline sysrq dummy function
USB: serial: only process sysrq when enabled
USB: serial: only set sysrq timestamp for consoles
USB: serial: ftdi_sio: fix break and sysrq handling
USB: serial: ftdi_sio: clean up receive processing
USB: serial: ftdi_sio: make process-packet buffer unsigned
USB: serial: use fallthrough pseudo-keyword
USB: serial: ch341: fix missing simulated-break margin
...
Devices sitting on proprietary busses have a device ID space that
is owned by the respective bus and related firmware bindings. In order
to let the generic OF layer handle the input translations to
an IOMMU id, for such busses the current of_dma_configure() interface
should be extended in order to allow the bus layer to provide the
device input id parameter - that is retrieved/assigned in bus
specific code and firmware.
Augment of_dma_configure() to add an optional input_id parameter,
leaving current functionality unchanged.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Link: https://lore.kernel.org/r/20200619082013.13661-8-lorenzo.pieralisi@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Some HW devices are created as child devices of proprietary busses,
that have a bus specific policy defining how the child devices
wires representing the devices ID are translated into IOMMU and
IRQ controllers device IDs.
Current IORT code provides translations for:
- PCI devices, where the device ID is well identified at bus level
as the requester ID (RID)
- Platform devices that are endpoint devices where the device ID is
retrieved from the ACPI object IORT mappings (Named components single
mappings). A platform device is represented in IORT as a named
component node
For devices that are child devices of proprietary busses the IORT
firmware represents the bus node as a named component node in IORT
and it is up to that named component node to define in/out bus
specific ID translations for the bus child devices that are
allocated and created in a bus specific manner.
In order to make IORT ID translations available for proprietary
bus child devices, the current ACPI (and IORT) code must be
augmented to provide an additional ID parameter to acpi_dma_configure()
representing the child devices input ID. This ID is bus specific
and it is retrieved in bus specific code.
By adding an ID parameter to acpi_dma_configure(), the IORT
code can map the child device ID to an IOMMU stream ID through
the IORT named component representing the bus in/out ID mappings.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://lore.kernel.org/r/20200619082013.13661-6-lorenzo.pieralisi@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
