[ Upstream commit 951a3f59d2 ]
[BUG]
The following reproducer can cause btrfs mount to fail:
dev="/dev/test/scratch1"
mnt1="/mnt/test"
mnt2="/mnt/scratch"
mkfs.btrfs -f $dev
mount $dev $mnt1
btrfs subvolume create $mnt1/subvol1
btrfs subvolume create $mnt1/subvol2
umount $mnt1
mount $dev $mnt1 -o subvol=subvol1
while mount -o remount,ro $mnt1; do mount -o remount,rw $mnt1; done &
bg=$!
while mount $dev $mnt2 -o subvol=subvol2; do umount $mnt2; done
kill $bg
wait
umount -R $mnt1
umount -R $mnt2
The script will fail with the following error:
mount: /mnt/scratch: /dev/mapper/test-scratch1 already mounted on /mnt/test.
dmesg(1) may have more information after failed mount system call.
umount: /mnt/test: target is busy.
umount: /mnt/scratch/: not mounted
And there is no kernel error message.
[CAUSE]
During the btrfs mount, to support mounting different subvolumes with
different RO/RW flags, we need to detect that and retry if needed:
Retry with matching RO flags if the initial mount fail with -EBUSY.
The problem is, during that retry we do not hold any super block lock
(s_umount), this means there can be a remount process changing the RO
flags of the original fs super block.
If so, we can have an EBUSY error during retry. And this time we treat
any failure as an error, without any retry and cause the above EBUSY
mount failure.
[FIX]
The current retry behavior is racy because we do not have a super block
thus no way to hold s_umount to prevent the race with remount.
Solve the root problem by allowing fc->sb_flags to mismatch from the
sb->s_flags at btrfs_get_tree_super().
Then at the re-entry point btrfs_get_tree_subvol(), manually check the
fc->s_flags against sb->s_flags, if it's a RO->RW mismatch, then
reconfigure with s_umount lock hold.
Reported-by: Enno Gotthold <egotthold@suse.com>
Reported-by: Fabian Vogt <fvogt@suse.com>
[ Special thanks for the reproducer and early analysis pointing to btrfs. ]
Fixes: f044b31867 ("btrfs: handle the ro->rw transition for mounting different subvolumes")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1231836
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 01c5db782e ]
The only caller passes NULL, we can drop the parameter. This is since
the new mount option parser done in 3bb17a25bc ("btrfs: add get_tree
callback for new mount API").
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 951a3f59d2 ("btrfs: fix mount failure due to remount races")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 87cbab8636 ]
Since the new mount option parser in commit ad21f15b0f ("btrfs:
switch to the new mount API") we don't pass the options like that
anymore.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 951a3f59d2 ("btrfs: fix mount failure due to remount races")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0664e2c311 ]
When running the following command:
while true; do
stress-ng --cyclic 30 --timeout 30s --minimize --quiet
done
a warning is eventually triggered:
WARNING: CPU: 43 PID: 2848 at kernel/sched/deadline.c:794
setup_new_dl_entity+0x13e/0x180
...
Call Trace:
<TASK>
? show_trace_log_lvl+0x1c4/0x2df
? enqueue_dl_entity+0x631/0x6e0
? setup_new_dl_entity+0x13e/0x180
? __warn+0x7e/0xd0
? report_bug+0x11a/0x1a0
? handle_bug+0x3c/0x70
? exc_invalid_op+0x14/0x70
? asm_exc_invalid_op+0x16/0x20
enqueue_dl_entity+0x631/0x6e0
enqueue_task_dl+0x7d/0x120
__do_set_cpus_allowed+0xe3/0x280
__set_cpus_allowed_ptr_locked+0x140/0x1d0
__set_cpus_allowed_ptr+0x54/0xa0
migrate_enable+0x7e/0x150
rt_spin_unlock+0x1c/0x90
group_send_sig_info+0xf7/0x1a0
? kill_pid_info+0x1f/0x1d0
kill_pid_info+0x78/0x1d0
kill_proc_info+0x5b/0x110
__x64_sys_kill+0x93/0xc0
do_syscall_64+0x5c/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
RIP: 0033:0x7f0dab31f92b
This warning occurs because set_cpus_allowed dequeues and enqueues tasks
with the ENQUEUE_RESTORE flag set. If the task is boosted, the warning
is triggered. A boosted task already had its parameters set by
rt_mutex_setprio, and a new call to setup_new_dl_entity is unnecessary,
hence the WARN_ON call.
Check if we are requeueing a boosted task and avoid calling
setup_new_dl_entity if that's the case.
Fixes: 295d6d5e37 ("sched/deadline: Fix switching to -deadline")
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20240724142253.27145-2-wander@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e932c4ab38 ]
Scheduler raises a SCHED_SOFTIRQ to trigger a load balancing event on
from the IPI handler on the idle CPU. If the SMP function is invoked
from an idle CPU via flush_smp_call_function_queue() then the HARD-IRQ
flag is not set and raise_softirq_irqoff() needlessly wakes ksoftirqd
because soft interrupts are handled before ksoftirqd get on the CPU.
Adding a trace_printk() in nohz_csd_func() at the spot of raising
SCHED_SOFTIRQ and enabling trace events for sched_switch, sched_wakeup,
and softirq_entry (for SCHED_SOFTIRQ vector alone) helps observing the
current behavior:
<idle>-0 [000] dN.1.: nohz_csd_func: Raising SCHED_SOFTIRQ from nohz_csd_func
<idle>-0 [000] dN.4.: sched_wakeup: comm=ksoftirqd/0 pid=16 prio=120 target_cpu=000
<idle>-0 [000] .Ns1.: softirq_entry: vec=7 [action=SCHED]
<idle>-0 [000] .Ns1.: softirq_exit: vec=7 [action=SCHED]
<idle>-0 [000] d..2.: sched_switch: prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=ksoftirqd/0 next_pid=16 next_prio=120
ksoftirqd/0-16 [000] d..2.: sched_switch: prev_comm=ksoftirqd/0 prev_pid=16 prev_prio=120 prev_state=S ==> next_comm=swapper/0 next_pid=0 next_prio=120
...
Use __raise_softirq_irqoff() to raise the softirq. The SMP function call
is always invoked on the requested CPU in an interrupt handler. It is
guaranteed that soft interrupts are handled at the end.
Following are the observations with the changes when enabling the same
set of events:
<idle>-0 [000] dN.1.: nohz_csd_func: Raising SCHED_SOFTIRQ for nohz_idle_balance
<idle>-0 [000] dN.1.: softirq_raise: vec=7 [action=SCHED]
<idle>-0 [000] .Ns1.: softirq_entry: vec=7 [action=SCHED]
No unnecessary ksoftirqd wakeups are seen from idle task's context to
service the softirq.
Fixes: b2a02fc43a ("smp: Optimize send_call_function_single_ipi()")
Closes: https://lore.kernel.org/lkml/fcf823f-195e-6c9a-eac3-25f870cb35ac@inria.fr/ [1]
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20241119054432.6405-5-kprateek.nayak@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ff47a0acfc ]
Commit b2a02fc43a ("smp: Optimize send_call_function_single_ipi()")
optimizes IPIs to idle CPUs in TIF_POLLING_NRFLAG mode by setting the
TIF_NEED_RESCHED flag in idle task's thread info and relying on
flush_smp_call_function_queue() in idle exit path to run the
call-function. A softirq raised by the call-function is handled shortly
after in do_softirq_post_smp_call_flush() but the TIF_NEED_RESCHED flag
remains set and is only cleared later when schedule_idle() calls
__schedule().
need_resched() check in _nohz_idle_balance() exists to bail out of load
balancing if another task has woken up on the CPU currently in-charge of
idle load balancing which is being processed in SCHED_SOFTIRQ context.
Since the optimization mentioned above overloads the interpretation of
TIF_NEED_RESCHED, check for idle_cpu() before going with the existing
need_resched() check which can catch a genuine task wakeup on an idle
CPU processing SCHED_SOFTIRQ from do_softirq_post_smp_call_flush(), as
well as the case where ksoftirqd needs to be preempted as a result of
new task wakeup or slice expiry.
In case of PREEMPT_RT or threadirqs, although the idle load balancing
may be inhibited in some cases on the ilb CPU, the fact that ksoftirqd
is the only fair task going back to sleep will trigger a newidle balance
on the CPU which will alleviate some imbalance if it exists if idle
balance fails to do so.
Fixes: b2a02fc43a ("smp: Optimize send_call_function_single_ipi()")
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241119054432.6405-4-kprateek.nayak@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ea9cffc0a1 ]
The need_resched() check currently in nohz_csd_func() can be tracked
to have been added in scheduler_ipi() back in 2011 via commit
ca38062e57 ("sched: Use resched IPI to kick off the nohz idle balance")
Since then, it has travelled quite a bit but it seems like an idle_cpu()
check currently is sufficient to detect the need to bail out from an
idle load balancing. To justify this removal, consider all the following
case where an idle load balancing could race with a task wakeup:
o Since commit f3dd3f6745 ("sched: Remove the limitation of WF_ON_CPU
on wakelist if wakee cpu is idle") a target perceived to be idle
(target_rq->nr_running == 0) will return true for
ttwu_queue_cond(target) which will offload the task wakeup to the idle
target via an IPI.
In all such cases target_rq->ttwu_pending will be set to 1 before
queuing the wake function.
If an idle load balance races here, following scenarios are possible:
- The CPU is not in TIF_POLLING_NRFLAG mode in which case an actual
IPI is sent to the CPU to wake it out of idle. If the
nohz_csd_func() queues before sched_ttwu_pending(), the idle load
balance will bail out since idle_cpu(target) returns 0 since
target_rq->ttwu_pending is 1. If the nohz_csd_func() is queued after
sched_ttwu_pending() it should see rq->nr_running to be non-zero and
bail out of idle load balancing.
- The CPU is in TIF_POLLING_NRFLAG mode and instead of an actual IPI,
the sender will simply set TIF_NEED_RESCHED for the target to put it
out of idle and flush_smp_call_function_queue() in do_idle() will
execute the call function. Depending on the ordering of the queuing
of nohz_csd_func() and sched_ttwu_pending(), the idle_cpu() check in
nohz_csd_func() should either see target_rq->ttwu_pending = 1 or
target_rq->nr_running to be non-zero if there is a genuine task
wakeup racing with the idle load balance kick.
o The waker CPU perceives the target CPU to be busy
(targer_rq->nr_running != 0) but the CPU is in fact going idle and due
to a series of unfortunate events, the system reaches a case where the
waker CPU decides to perform the wakeup by itself in ttwu_queue() on
the target CPU but target is concurrently selected for idle load
balance (XXX: Can this happen? I'm not sure, but we'll consider the
mother of all coincidences to estimate the worst case scenario).
ttwu_do_activate() calls enqueue_task() which would increment
"rq->nr_running" post which it calls wakeup_preempt() which is
responsible for setting TIF_NEED_RESCHED (via a resched IPI or by
setting TIF_NEED_RESCHED on a TIF_POLLING_NRFLAG idle CPU) The key
thing to note in this case is that rq->nr_running is already non-zero
in case of a wakeup before TIF_NEED_RESCHED is set which would
lead to idle_cpu() check returning false.
In all cases, it seems that need_resched() check is unnecessary when
checking for idle_cpu() first since an impending wakeup racing with idle
load balancer will either set the "rq->ttwu_pending" or indicate a newly
woken task via "rq->nr_running".
Chasing the reason why this check might have existed in the first place,
I came across Peter's suggestion on the fist iteration of Suresh's
patch from 2011 [1] where the condition to raise the SCHED_SOFTIRQ was:
sched_ttwu_do_pending(list);
if (unlikely((rq->idle == current) &&
rq->nohz_balance_kick &&
!need_resched()))
raise_softirq_irqoff(SCHED_SOFTIRQ);
Since the condition to raise the SCHED_SOFIRQ was preceded by
sched_ttwu_do_pending() (which is equivalent of sched_ttwu_pending()) in
the current upstream kernel, the need_resched() check was necessary to
catch a newly queued task. Peter suggested modifying it to:
if (idle_cpu() && rq->nohz_balance_kick && !need_resched())
raise_softirq_irqoff(SCHED_SOFTIRQ);
where idle_cpu() seems to have replaced "rq->idle == current" check.
Even back then, the idle_cpu() check would have been sufficient to catch
a new task being enqueued. Since commit b2a02fc43a ("smp: Optimize
send_call_function_single_ipi()") overloads the interpretation of
TIF_NEED_RESCHED for TIF_POLLING_NRFLAG idling, remove the
need_resched() check in nohz_csd_func() to raise SCHED_SOFTIRQ based
on Peter's suggestion.
Fixes: b2a02fc43a ("smp: Optimize send_call_function_single_ipi()")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241119054432.6405-3-kprateek.nayak@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 70ee7947a2 ]
Commit 8f9ea86fdf added some logic to sched_setaffinity that included
a WARN when a per-task affinity assignment races with a cpuset update.
Specifically, we can have a race where a cpuset update results in the
task affinity no longer being a subset of the cpuset. That's fine; we
have a fallback to instead use the cpuset mask. However, we have a WARN
set up that will trigger if the cpuset mask has no overlap at all with
the requested task affinity. This shouldn't be a warning condition; its
trivial to create this condition.
Reproduced the warning by the following setup:
- $PID inside a cpuset cgroup
- another thread repeatedly switching the cpuset cpus from 1-2 to just 1
- another thread repeatedly setting the $PID affinity (via taskset) to 2
Fixes: 8f9ea86fdf ("sched: Always preserve the user requested cpumask")
Signed-off-by: Josh Don <joshdon@google.com>
Acked-and-tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
Link: https://lkml.kernel.org/r/20241111182738.1832953-1-joshdon@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6a7fd76b94 ]
[WHY]
For better power profiling knowing the detile
buffer size at a given point in time
would be useful.
[HOW]
Add interface to retrieve detile buffer from
dc state.
Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Sung Lee <Sung.Lee@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9ffd6ec2de ]
xe_force_wake_get() now returns the reference count-incremented domain
mask. If it fails for individual domains, the return value will always
be 0. However, for XE_FORCEWAKE_ALL, it may return a non-zero value even
in the event of failure. Use helper xe_force_wake_ref_has_domain to
verify all domains are initialized or not. Update the return handling of
xe_force_wake_get() to reflect this behavior, and ensure that the return
value is passed as input to xe_force_wake_put().
v3
- return xe_wakeref_t instead of int in xe_force_wake_get()
v5
- return unsigned int for xe_force_wake_get()
v6
- use helper xe_force_wake_ref_has_domain()
v7
- Fix commit message
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241014075601.2324382-12-himal.prasad.ghimiray@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Stable-dep-of: 5dce85fecb ("drm/xe: Move the coredump registration to the worker thread")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a59a403419 ]
Add an extra stage to the GuC log print to copy the log buffer into
regular host memory first, rather than printing the live GPU buffer
object directly. Doing so helps prevent inconsistencies due to the log
being updated as it is being dumped. It also allows the use of the
ASCII85 helper function for printing the log in a more compact form
than a straight hex dump.
v2: Use %zx instead of %lx for size_t prints.
v3: Replace hexdump code with ascii85 call (review feedback from
Matthew B). Move chunking code into next patch as that reduces the
deltas of both.
v4: Add a prefix to the ASCII85 output to aid tool parsing.
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Julia Filipchuk <julia.filipchuk@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241003004611.2323493-6-John.C.Harrison@Intel.com
Stable-dep-of: 5dce85fecb ("drm/xe: Move the coredump registration to the worker thread")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec1455ce7e ]
There is a need to include the GuC log and other large binary objects
in core dumps and via dmesg. So add a helper for dumping to a printer
function via conversion to ASCII85 encoding.
Another issue with dumping such a large buffer is that it can be slow,
especially if dumping to dmesg over a serial port. So add a yield to
prevent the 'task has been stuck for 120s' kernel hang check feature
from firing.
v2: Add a prefix to the output string. Fix memory allocation bug.
v3: Correct a string size calculation and clean up a define (review
feedback from Julia F).
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Julia Filipchuk <julia.filipchuk@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241003004611.2323493-5-John.C.Harrison@Intel.com
Stable-dep-of: 5dce85fecb ("drm/xe: Move the coredump registration to the worker thread")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c28fd6c358 ]
The xe_guc_exec_queue_snapshot is not really a GuC internal thing and
is definitely not a GuC CT thing. So give it its own section heading.
The snapshot itself is really a capture of the submission backend's
internal state. Although all it currently prints out is the submission
contexts. So label it as 'Contexts'. If more general state is added
later then it could be change to 'Submission backend' or some such.
Further, everything from the GuC CT section onwards is GT specific but
there was no indication of which GT it was related to (and that is
impossible to work out from the other fields that are given). So add a
GT section heading. Also include the tile id of the GT, because again
significant information.
Lastly, drop a couple of unnecessary line feeds within sections.
v2: Add GT section heading, add tile id to device section.
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Julia Filipchuk <julia.filipchuk@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241003004611.2323493-4-John.C.Harrison@Intel.com
Stable-dep-of: 5dce85fecb ("drm/xe: Move the coredump registration to the worker thread")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9d86d080cf ]
There are a bunch of calls to drm_printf with static strings. Switch
them to drm_puts instead.
There are also a bunch of 'coredump->snapshot.XXX' references when
'coredump->snapshot' has alread been cached locally as 'ss'. So use
'ss->XXX' instead.
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Julia Filipchuk <julia.filipchuk@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241003004611.2323493-3-John.C.Harrison@Intel.com
Stable-dep-of: 5dce85fecb ("drm/xe: Move the coredump registration to the worker thread")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 897df60c16 ]
This will ensure that the scsi host is cleaned up properly using
scsi_host_dev_release(). Otherwise, it may lead to memory leaks.
Cc: stable@vger.kernel.org # 4.4
Fixes: 03b1781aa9 ("[SCSI] ufs: Add Platform glue driver for ufshcd")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20241111-ufs_bug_fix-v1-5-45ad8b62f02e@linaro.org
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7eb75ce752 ]
syzbot triggered the following WARN_ON:
WARNING: CPU: 0 PID: 16 at io_uring/tctx.c:51 __io_uring_free+0xfa/0x140 io_uring/tctx.c:51
which is the
WARN_ON_ONCE(!xa_empty(&tctx->xa));
sanity check in __io_uring_free() when a io_uring_task is going through
its final put. The syzbot test case includes injecting memory allocation
failures, and it very much looks like xa_store() can fail one of its
memory allocations and end up with ->head being non-NULL even though no
entries exist in the xarray.
Until this issue gets sorted out, work around it by attempting to
iterate entries in our xarray, and WARN_ON_ONCE() if one is found.
Reported-by: syzbot+cc36d44ec9f368e443d3@syzkaller.appspotmail.com
Link: https://lore.kernel.org/io-uring/673c1643.050a0220.87769.0066.GAE@google.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 523f3dbc18 ]
Contrary to expectations, passing a single candidate tag to "git
describe" is slower than not passing any --match options.
$ time git describe --debug
...
traversed 10619 commits
...
v6.12-rc5-63-g0fc810ae3ae1
real 0m0.169s
$ time git describe --match=v6.12-rc5 --debug
...
traversed 1310024 commits
v6.12-rc5-63-g0fc810ae3ae1
real 0m1.281s
In fact, the --debug output shows that git traverses all or most of
history. For some repositories and/or git versions, those 1.3s are
actually 10-15 seconds.
This has been acknowledged as a performance bug in git [1], and a fix
is on its way [2]. However, no solution is yet in git.git, and even
when one lands, it will take quite a while before it finds its way to
a release and for $random_kernel_developer to pick that up.
So rewrite the logic to use plumbing commands. For each of the
candidate values of $tag, we ask: (1) is $tag even an annotated
tag? (2) Is it eligible to describe HEAD, i.e. an ancestor of
HEAD? (3) If so, how many commits are in $tag..HEAD?
I have tested that this produces the same output as the current script
for ~700 random commits between v6.9..v6.10. For those 700 commits,
and in my git repo, the 'make -s kernelrelease' command is on average
~4 times faster with this patch applied (geometric mean of ratios).
For the commit mentioned in Josh's original report [3], the
time-consuming part of setlocalversion goes from
$ time git describe --match=v6.12-rc5 c1e939a21e
v6.12-rc5-44-gc1e939a21eb1
real 0m1.210s
to
$ time git rev-list --count --left-right v6.12-rc5..c1e939a21eb1
0 44
real 0m0.037s
[1] https://lore.kernel.org/git/20241101113910.GA2301440@coredump.intra.peff.net/
[2] https://lore.kernel.org/git/20241106192236.GC880133@coredump.intra.peff.net/
[3] https://lore.kernel.org/lkml/309549cafdcfe50c4fceac3263220cc3d8b109b2.1730337435.git.jpoimboe@kernel.org/
Reported-by: Sean Christopherson <seanjc@google.com>
Closes: https://lore.kernel.org/lkml/ZPtlxmdIJXOe0sEy@google.com/
Reported-by: Josh Poimboeuf <jpoimboe@kernel.org>
Closes: https://lore.kernel.org/lkml/309549cafdcfe50c4fceac3263220cc3d8b109b2.1730337435.git.jpoimboe@kernel.org/
Tested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 36008fe6e3 ]
We can't properly support chasing DFS links in cifs_tree_connect()
because
(1) We don't support creating new sessions while we're reconnecting,
which would be required for DFS interlinks.
(2) ->is_path_accessible() can't be called from cifs_tree_connect()
as it would deadlock with smb2_reconnect(). This is required for
checking if new DFS target is a nested DFS link.
By unconditionally trying to get an DFS referral from new DFS target
isn't correct because if the new DFS target (interlink) is an DFS
standalone namespace, then we would end up getting -ELOOP and then
potentially leaving tcon disconnected.
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f82e62d470 ]
When enabling GICv4.1 in hip09, VMAPP fails to clear some caches during
the unmap operation, which can causes vSGIs to be lost.
To fix the issue, invalidate the related vPE cache through GICR_INVALLR
after VMOVP.
Suggested-by: Marc Zyngier <maz@kernel.org>
Co-developed-by: Nianyao Tang <tangnianyao@huawei.com>
Signed-off-by: Nianyao Tang <tangnianyao@huawei.com>
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8448828216 ]
This reverts commit d06923670b.
It was realized that the fix implemented to contain the race condition
among the keep alive task and the fabric shutdown code path in the commit
d06923670b5ia ("nvme: make keep-alive synchronous operation") is not
optimal. The reason being keep-alive runs under the workqueue and making
it synchronous would waste a workqueue context.
Furthermore, we later found that the above race condition is a regression
caused due to the changes implemented in commit a54a93d0e3 ("nvme: move
stopping keep-alive into nvme_uninit_ctrl()"). So we decided to revert the
commit d06923670b ("nvme: make keep-alive synchronous operation") and
then fix the regression.
Link: https://lore.kernel.org/all/196f4013-3bbf-43ff-98b4-9cb2a96c20c2@grimberg.me/
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cad4dda82c ]
SG2044 relys on an internal divisor when calculating bitrate, which
means a wrong clock for the most common bitrates. So add a quirk for
this uart device to skip the set rate call and only relys on the
internal UART divisor.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Link: https://lore.kernel.org/r/20241024062105.782330-4-inochiama@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0a6efab33e ]
On my device reading entirety of /sys/devices/pnp0/00:03/cmos_nvram0/nvmem
takes about 9 msec during which time interrupts are off on the CPU that
does the read and the thread that performs the read can not be migrated
or preempted by another higher priority thread (RT or not).
Allow readers and writers be preempted by taking and releasing rtc_lock
spinlock for each individual byte read or written rather than once per
read/write request.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Link: https://lore.kernel.org/r/Zxv8QWR21AV4ztC5@google.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7738a7ab9d ]
Add a quirk similar to eeprom_93xx46 to add an extra clock cycle before
reading data from the EEPROM.
The 93Cx6 family of EEPROMs output a "dummy 0 bit" between the writing
of the op-code/address from the host to the EEPROM and the reading of
the actual data from the EEPROM.
More info can be found on page 6 of the AT93C46 datasheet (linked below).
Similar notes are found in other 93xx6 datasheets.
In summary the read operation for a 93Cx6 EEPROM is:
Write to EEPROM: 110[A5-A0] (9 bits)
Read from EEPROM: 0[D15-D0] (17 bits)
Where:
110 is the start bit and READ OpCode
[A5-A0] is the address to read from
0 is a "dummy bit" preceding the actual data
[D15-D0] is the actual data.
Looking at the READ timing diagrams in the 93Cx6 datasheets the dummy
bit should be clocked out on the last address bit clock cycle meaning it
should be discarded naturally.
However, depending on the hardware configuration sometimes this dummy
bit is not discarded. This is the case with Exar PCI UARTs which require
an extra clock cycle between sending the address and reading the data.
Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-5193-SEEPROM-AT93C46D-Datasheet.pdf
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Parker Newman <pnewman@connecttech.com>
Link: https://lore.kernel.org/r/0f23973efefccd2544705a0480b4ad4c2353e407.1727880931.git.pnewman@connecttech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cf89c9434a ]
On some powermacs `escc` nodes are missing `#size-cells` properties,
which is deprecated and now triggers a warning at boot since commit
045b14ca5c ("of: WARN on deprecated #address-cells/#size-cells
handling").
For example:
Missing '#size-cells' in /pci@f2000000/mac-io@c/escc@13000
WARNING: CPU: 0 PID: 0 at drivers/of/base.c:133 of_bus_n_size_cells+0x98/0x108
Hardware name: PowerMac3,1 7400 0xc0209 PowerMac
...
Call Trace:
of_bus_n_size_cells+0x98/0x108 (unreliable)
of_bus_default_count_cells+0x40/0x60
__of_get_address+0xc8/0x21c
__of_address_to_resource+0x5c/0x228
pmz_init_port+0x5c/0x2ec
pmz_probe.isra.0+0x144/0x1e4
pmz_console_init+0x10/0x48
console_init+0xcc/0x138
start_kernel+0x5c4/0x694
As powermacs boot via prom_init it's possible to add the missing
properties to the device tree during boot, avoiding the warning. Note
that `escc-legacy` nodes are also missing `#size-cells` properties, but
they are skipped by the macio driver, so leave them alone.
Depends-on: 045b14ca5c ("of: WARN on deprecated #address-cells/#size-cells handling")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20241126025710.591683-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4fbd66d825 ]
Fix the dtc warnings:
arch/mips/boot/dts/loongson/ls7a-pch.dtsi:68.16-416.5: Warning (interrupt_provider): /bus@10000000/pci@1a000000: '#interrupt-cells' found, but node is not an interrupt provider
arch/mips/boot/dts/loongson/ls7a-pch.dtsi:68.16-416.5: Warning (interrupt_provider): /bus@10000000/pci@1a000000: '#interrupt-cells' found, but node is not an interrupt provider
arch/mips/boot/dts/loongson/loongson64g_4core_ls7a.dtb: Warning (interrupt_map): Failed prerequisite 'interrupt_provider'
And a runtime warning introduced in commit 045b14ca5c ("of: WARN on
deprecated #address-cells/#size-cells handling"):
WARNING: CPU: 0 PID: 1 at drivers/of/base.c:106 of_bus_n_addr_cells+0x9c/0xe0
Missing '#address-cells' in /bus@10000000/pci@1a000000/pci_bridge@9,0
The fix is similar to commit d89a415ff8 ("MIPS: Loongson64: DTS: Fix PCIe
port nodes for ls7a"), which has fixed the issue for ls2k (despite its
subject mentions ls7a).
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 928cd772e1 ]
It is not necessarily corrupted. When there is RAS fatal error, device
memory access is blocked. Hence vcpu bo cannot be saved to system memory
as in a regular suspend sequence before going for reset. In other full
device reset cases, that gets saved and restored during resume.
v2: Remove redundant code like vcn_v4_0 did
v2: Refine commit message
v3: Drop the volatile
v3: Refine commit message
Signed-off-by: Xiang Liu <xiang.liu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Stanley.Yang <Stanley.Yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 67a0463d33 ]
This laptop model requires an additional detection quirk to enable the
internal microphone
Signed-off-by: Alex Far <anf1980@gmail.com>
Link: https://patch.msgid.link/ZzjrZY3sImcqTtGx@RedmiG
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit de9df030cc ]
Instead of checking if any of the USB-C ports have orientation GPIO and
thus is orientation-aware, check for the GPIO for the port being
registered. There are no boards that are affected by this change at this
moment, so the patch is not marked as a fix, but it might affect other
boards in future.
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20241109-ucsi-glue-fixes-v2-2-8b21ff4f9fbe@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fa48d7e816 ]
ACPI _DSM methods are needed only for UCSI write operations and for reading
CCI during RESET_PPM operation. So, remove _DSM calls from other places.
While there, remove the Zenbook quirk also since the default behavior
now aligns with the Zenbook quirk. With this change, GET_CONNECTOR_STATUS
returns at least 6 seconds faster than before in Arrowlake-S platforms.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
Reviewed-by: Christian A. Ehrhardt <lk@c--e.de>
Link: https://lore.kernel.org/r/20240830084342.460109-1-saranya.gopal@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 548f48b66c ]
As per USBSTS register description about UEI:
When completion of a USB transaction results in an error condition, this
bit is set by the Host/Device Controller. This bit is set along with the
USBINT bit, if the TD on which the error interrupt occurred also had its
interrupt on complete (IOC) bit set.
UI is set only when IOC set. Add checking UEI to fix miss call
isr_tr_complete_handler() when IOC have not set and transfer error happen.
Acked-by: Peter Chen <peter.chen@kernel.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240926022906.473319-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit edfcc455c8 ]
The chipidea controller doesn't fully support sglist, such as it can not
transfer data spanned more dTDs to form a bus packet, so it can only work
on very limited cases.
The limitations as below:
1. the end address of the first sg buffer must be 4KB aligned.
2. the start and end address of the middle sg buffer must be 4KB aligned.
3. the start address of the first sg buffer must be 4KB aligned.
However, not all the use cases violate these limitations. To make the
controller compatible with most of the cases, this will try to bounce the
problem sglist entries which can be found by sglist_get_invalid_entry().
Then a bounced line buffer (the size will roundup to page size) will be
allocated to replace the remaining problem sg entries. The data will be
copied between problem sg entries and bounce buffer according to the
transfer direction. The bounce buffer will be freed when the request
completed.
Acked-by: Peter Chen <peter.chen@kernel.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240923081203.2851768-3-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ca8d18aa7b ]
To let the device controller work properly on short packet limitations,
one usb request should only correspond to one dTD. Then every dTD will
set IOC. In theory, each dTD support up to 20KB data transfer if the
offset is 0. Due to we cannot predetermine the offset, this will limit
the usb request length to max 16KB. This should be fine since most of
the user transfer data based on this size policy.
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20240923081203.2851768-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec841b8d73 ]
Currently, the imx deivice controller has below limitations:
1. can't generate short packet interrupt if IOC not set in dTD. So if one
request span more than one dTDs and only the last dTD set IOC, the usb
request will pending there if no more data comes.
2. the controller can't accurately deliver data to differtent usb requests
in some cases due to short packet. For example: one usb request span 3
dTDs, then if the controller received a short packet the next packet
will go to 2nd dTD of current request rather than the first dTD of next
request.
3. can't build a bus packet use multiple dTDs. For example: controller
needs to send one packet of 512 bytes use dTD1 (200 bytes) + dTD2
(312 bytes), actually the host side will see 200 bytes short packet.
Based on these limits, add CI_HDRC_HAS_SHORT_PKT_LIMIT flag and use it on
imx platforms.
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20240923081203.2851768-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eeecf953d6 ]
All FTSMPS525 regulators support LV and MV ranges; however,
the boot loader firmware will determine which range to use as
the device boots.
Nonetheless, the driver cannot determine which range was selected,
so hardcoding the ranges as either LV or MV will not cover all cases
as it's possible for the firmware to select a range not supported by
the driver's current hardcoded values.
To this end, combine the ranges for the FTSMPS525s into one struct
and point all regulators to the updated combined struct. This should
work on all boards regardless of which range is selected by the firmware
and more accurately caputres the capability of this regulator on a
hardware level.
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patch.msgid.link/20241112002645.2803506-1-quic_molvera@quicinc.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e2705dd3d1 ]
Use local runs_tree instead of cached. This way excludes rw_semaphore lock.
Reported-by: syzbot+1c25748a40fe79b8a119@syzkaller.appspotmail.com
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bd8aa15848 ]
The Asus entries in the acpi_quirk_skip_dmi_ids[] table are the only
entries without a comment which model they apply to. Add these comments.
The Asus TF103C entry also is in the wrong place for what is supposed to
be an alphabetically sorted list. Move it up so that the list is properly
sorted and add a comment that the list is alphabetically sorted.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patch.msgid.link/20241116095825.11660-2-hdegoede@redhat.com
[ rjw: Changelog and subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 82f250ed1a ]
The Acer Iconia One 8 A1-840 (not to be confused with the A1-840FHD which
is a different model) ships with Android 4.4 as factory OS and has the
usual broken DSDT issues for x86 Android tablets.
Add quirks to skip ACPI I2C client enumeration and disable ACPI battery/AC
and ACPI GPIO event handlers.
Also add the "INT33F5" HID for the TI PMIC used on this tablet to the list
of HIDs for which not to skip i2c_client instantiation, since we do want
an ACPI instantiated i2c_client for the PMIC.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patch.msgid.link/20241116095825.11660-1-hdegoede@redhat.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 009a8241a8 ]
Quoted:
"at this time, there are still 1086911 extent nodes in this zombie
extent tree that need to be cleaned up.
crash_arm64_sprd_v8.0.3++> extent_tree.node_cnt ffffff80896cc500
node_cnt = {
counter = 1086911
},
"
As reported by Xiuhong, there will be a huge number of extent nodes
in extent tree, it may potentially cause:
- slab memory fragments
- extreme long time shrink on extent tree
- low mapping efficiency
Let's add a sysfs node to limit max read extent count for each inode,
by default, value of this threshold is 10240, it can be updated
according to user's requirement.
Reported-by: Xiuhong Wang <xiuhong.wang@unisoc.com>
Closes: https://lore.kernel.org/linux-f2fs-devel/20241112110627.1314632-1-xiuhong.wang@unisoc.com/
Signed-off-by: Xiuhong Wang <xiuhong.wang@unisoc.com>
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3fc5d5a182 ]
We use rwlock to protect core structure data of extent tree during
its shrink, however, if there is a huge number of extent nodes in
extent tree, during shrink of extent tree, it may hold rwlock for
a very long time, which may trigger kernel hang issue.
This patch fixes to shrink read extent node in batches, so that,
critical region of the rwlock can be shrunk to avoid its extreme
long time hold.
Reported-by: Xiuhong Wang <xiuhong.wang@unisoc.com>
Closes: https://lore.kernel.org/linux-f2fs-devel/20241112110627.1314632-1-xiuhong.wang@unisoc.com/
Signed-off-by: Xiuhong Wang <xiuhong.wang@unisoc.com>
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 81520c684c ]
If fs corruption occurs in f2fs_new_node_page(), let's print
more information about corrupted metadata into kernel log.
Meanwhile, it updates to record ERROR_INCONSISTENT_NAT instead
of ERROR_INVALID_BLKADDR if blkaddr in nat entry is not
NULL_ADDR which means nat bitmap and nat entry is inconsistent.
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aa46a3736a ]
Wangxun FF5xxx NICs are similar to SFxxx, RP1000 and RP2000 NICs. They may
be multi-function devices, but they do not advertise an ACS capability.
But the hardware does isolate FF5xxx functions as though it had an ACS
capability and PCI_ACS_RR and PCI_ACS_CR were set in the ACS Control
register, i.e., all peer-to-peer traffic is directed upstream instead of
being routed internally.
Add ACS quirk for FF5xxx NICs in pci_quirk_wangxun_nic_acs() so the
functions can be in independent IOMMU groups.
Link: https://lore.kernel.org/r/E16053DB2B80E9A5+20241115024604.30493-1-mengyuanlou@net-swift.com
Signed-off-by: Mengyuan Lou <mengyuanlou@net-swift.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2fa046449a ]
The "bus" and "cxl_bus" reset methods reset a device by asserting Secondary
Bus Reset on the bridge leading to the device. These only work if the
device is the only device below the bridge.
Add a sysfs 'reset_subordinate' attribute on bridges that can assert
Secondary Bus Reset regardless of how many devices are below the bridge.
This resets all the devices below a bridge in a single command, including
the locking and config space save/restore that reset methods normally do.
This may be the only way to reset devices that don't support other reset
methods (ACPI, FLR, PM reset, etc).
Link: https://lore.kernel.org/r/20241025222755.3756162-1-kbusch@meta.com
Signed-off-by: Keith Busch <kbusch@kernel.org>
[bhelgaas: commit log, add capable(CAP_SYS_ADMIN) check]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Amey Narkhede <ameynarkhede03@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
