drm/i915: Fix premature release of request's reusable memory

Infinite waits for completion of GPU activity have been observed in CI,
mostly inside __i915_active_wait(), triggered by igt@gem_barrier_

drm/i915: Fix premature release of request's reusable memory

Infinite waits for completion of GPU activity have been observed in CI,
mostly inside __i915_active_wait(), triggered by igt@gem_barrier_race or
igt@perf@stress-open-close. Root cause analysis, based of ftrace dumps
generated with a lot of extra trace_printk() calls added to the code,
revealed loops of request dependencies being accidentally built,
preventing the requests from being processed, each waiting for completion
of another one's activity.

After we substitute a new request for a last active one tracked on a
timeline, we set up a dependency of our new request to wait on completion
of current activity of that previous one. While doing that, we must take
care of keeping the old request still in memory until we use its
attributes for setting up that await dependency, or we can happen to set
up the await dependency on an unrelated request that already reuses the
memory previously allocated to the old one, already released. Combined
with perf adding consecutive kernel context remote requests to different
user context timelines, unresolvable loops of await dependencies can be
built, leading do infinite waits.

We obtain a pointer to the previous request to wait upon when we
substitute it with a pointer to our new request in an active tracker,
e.g. in intel_timeline.last_request. In some processing paths we protect
that old request from being freed before we use it by getting a reference
to it under RCU protection, but in others, e.g. __i915_request_commit()
-> __i915_request_add_to_timeline() -> __i915_request_ensure_ordering(),
we don't. But anyway, since the requests' memory is SLAB_FAILSAFE_BY_RCU,
that RCU protection is not sufficient against reuse of memory.

We could protect i915_request's memory from being prematurely reused by
calling its release function via call_rcu() and using rcu_read_lock()
consequently, as proposed in v1. However, that approach leads to
significant (up to 10 times) increase of SLAB utilization by i915_request
SLAB cache. Another potential approach is to take a reference to the
previous active fence.

When updating an active fence tracker, we first lock the new fence,
substitute a pointer of the current active fence with the new one, then we
lock the substituted fence. With this approach, there is a time window
after the substitution and before the lock when the request can be
concurrently released by an interrupt handler and its memory reused, then
we may happen to lock and return a new, unrelated request.

Always get a reference to the current active fence first, before
replacing it with a new one. Having it protected from premature release
and reuse, lock it and then replace with the new one but only if not
yet signalled via a potential concurrent interrupt nor replaced with
another one by a potential concurrent thread, otherwise retry, starting
from getting a reference to the new current one. Adjust users to not
get a reference to the previous active fence themselves and always put the
reference got by __i915_active_fence_set() when no longer needed.

v3: Fix lockdep splat reports and other issues caused by incorrect use of
try_cmpxchg() (use (cmpxchg() != prev) instead)
v2: Protect request's memory by getting a reference to it in favor of
delegating its release to call_rcu() (Chris)

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8211
Fixes: df9f85d8582e ("drm/i915: Serialise i915_active_fence_set() with itself")
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.6+
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230720093543.832147-2-janusz.krzysztofik@linux.intel.com
(cherry picked from commit 946e047a3d88d46d15b5c5af0414098e12b243f7)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

show more ...

drm/i915: Fix premature release of request's reusable memory

Infinite waits for completion of GPU activity have been observed in CI,
mostly inside __i915_active_wait(), triggered by igt@gem_barrier_

drm/i915: Fix premature release of request's reusable memory

Infinite waits for completion of GPU activity have been observed in CI,
mostly inside __i915_active_wait(), triggered by igt@gem_barrier_race or
igt@perf@stress-open-close. Root cause analysis, based of ftrace dumps
generated with a lot of extra trace_printk() calls added to the code,
revealed loops of request dependencies being accidentally built,
preventing the requests from being processed, each waiting for completion
of another one's activity.

After we substitute a new request for a last active one tracked on a
timeline, we set up a dependency of our new request to wait on completion
of current activity of that previous one. While doing that, we must take
care of keeping the old request still in memory until we use its
attributes for setting up that await dependency, or we can happen to set
up the await dependency on an unrelated request that already reuses the
memory previously allocated to the old one, already released. Combined
with perf adding consecutive kernel context remote requests to different
user context timelines, unresolvable loops of await dependencies can be
built, leading do infinite waits.

We obtain a pointer to the previous request to wait upon when we
substitute it with a pointer to our new request in an active tracker,
e.g. in intel_timeline.last_request. In some processing paths we protect
that old request from being freed before we use it by getting a reference
to it under RCU protection, but in others, e.g. __i915_request_commit()
-> __i915_request_add_to_timeline() -> __i915_request_ensure_ordering(),
we don't. But anyway, since the requests' memory is SLAB_FAILSAFE_BY_RCU,
that RCU protection is not sufficient against reuse of memory.

We could protect i915_request's memory from being prematurely reused by
calling its release function via call_rcu() and using rcu_read_lock()
consequently, as proposed in v1. However, that approach leads to
significant (up to 10 times) increase of SLAB utilization by i915_request
SLAB cache. Another potential approach is to take a reference to the
previous active fence.

When updating an active fence tracker, we first lock the new fence,
substitute a pointer of the current active fence with the new one, then we
lock the substituted fence. With this approach, there is a time window
after the substitution and before the lock when the request can be
concurrently released by an interrupt handler and its memory reused, then
we may happen to lock and return a new, unrelated request.

Always get a reference to the current active fence first, before
replacing it with a new one. Having it protected from premature release
and reuse, lock it and then replace with the new one but only if not
yet signalled via a potential concurrent interrupt nor replaced with
another one by a potential concurrent thread, otherwise retry, starting
from getting a reference to the new current one. Adjust users to not
get a reference to the previous active fence themselves and always put the
reference got by __i915_active_fence_set() when no longer needed.

v3: Fix lockdep splat reports and other issues caused by incorrect use of
try_cmpxchg() (use (cmpxchg() != prev) instead)
v2: Protect request's memory by getting a reference to it in favor of
delegating its release to call_rcu() (Chris)

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8211
Fixes: df9f85d8582e ("drm/i915: Serialise i915_active_fence_set() with itself")
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.6+
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230720093543.832147-2-janusz.krzysztofik@linux.intel.com

show more ...

drm/i915/active: Fix missing debug object activation

debug_active_activate() expected ref->count to be zero
which is not true anymore as __i915_active_activate() calls
debug_active_activate() after

drm/i915/active: Fix missing debug object activation

debug_active_activate() expected ref->count to be zero
which is not true anymore as __i915_active_activate() calls
debug_active_activate() after incrementing the count.

v2: No need to check for "ref->count == 1" as __i915_active_activate()
already make sure of that(Janusz).

References: https://gitlab.freedesktop.org/drm/intel/-/issues/6733
Fixes: 04240e30ed06 ("drm/i915: Skip taking acquire mutex for no ref->active callback")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@intel.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230313114613.9874-1-nirmoy.das@intel.com
(cherry picked from commit bfad380c542438a9b642f8190b7fd37bc77e2723)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

show more ...

drm/i915/active: Fix missing debug object activation

debug_active_activate() expected ref->count to be zero
which is not true anymore as __i915_active_activate() calls
debug_active_activate() after

drm/i915/active: Fix missing debug object activation

debug_active_activate() expected ref->count to be zero
which is not true anymore as __i915_active_activate() calls
debug_active_activate() after incrementing the count.

v2: No need to check for "ref->count == 1" as __i915_active_activate()
already make sure of that(Janusz).

References: https://gitlab.freedesktop.org/drm/intel/-/issues/6733
Fixes: 04240e30ed06 ("drm/i915: Skip taking acquire mutex for no ref->active callback")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@intel.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230313114613.9874-1-nirmoy.das@intel.com

show more ...

drm/i915/active: Fix misuse of non-idle barriers as fence trackers

Users reported oopses on list corruptions when using i915 perf with a
number of concurrently running graphics applications. Root c

drm/i915/active: Fix misuse of non-idle barriers as fence trackers

Users reported oopses on list corruptions when using i915 perf with a
number of concurrently running graphics applications. Root cause analysis
pointed at an issue in barrier processing code -- a race among perf open /
close replacing active barriers with perf requests on kernel context and
concurrent barrier preallocate / acquire operations performed during user
context first pin / last unpin.

When adding a request to a composite tracker, we try to reuse an existing
fence tracker, already allocated and registered with that composite. The
tracker we obtain may already track another fence, may be an idle barrier,
or an active barrier.

If the tracker we get occurs a non-idle barrier then we try to delete that
barrier from a list of barrier tasks it belongs to. However, while doing
that we don't respect return value from a function that performs the
barrier deletion. Should the deletion ever fail, we would end up reusing
the tracker still registered as a barrier task. Since the same structure
field is reused with both fence callback lists and barrier tasks list,
list corruptions would likely occur.

Barriers are now deleted from a barrier tasks list by temporarily removing
the list content, traversing that content with skip over the node to be
deleted, then populating the list back with the modified content. Should
that intentionally racy concurrent deletion attempts be not serialized,
one or more of those may fail because of the list being temporary empty.

Related code that ignores the results of barrier deletion was initially
introduced in v5.4 by commit d8af05ff38ae ("drm/i915: Allow sharing the
idle-barrier from other kernel requests"). However, all users of the
barrier deletion routine were apparently serialized at that time, then the
issue didn't exhibit itself. Results of git bisect with help of a newly
developed igt@gem_barrier_race@remote-request IGT test indicate that list
corruptions might start to appear after commit 311770173fac ("drm/i915/gt:
Schedule request retirement when timeline idles"), introduced in v5.5.

Respect results of barrier deletion attempts -- mark the barrier as idle
only if successfully deleted from the list. Then, before proceeding with
setting our fence as the one currently tracked, make sure that the tracker
we've got is not a non-idle barrier. If that check fails then don't use
that tracker but go back and try to acquire a new, usable one.

v3: use unlikely() to document what outcome we expect (Andi),
- fix bad grammar in commit description.
v2: no code changes,
- blame commit 311770173fac ("drm/i915/gt: Schedule request retirement
when timeline idles"), v5.5, not commit d8af05ff38ae ("drm/i915: Allow
sharing the idle-barrier from other kernel requests"), v5.4,
- reword commit description.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6333
Fixes: 311770173fac ("drm/i915/gt: Schedule request retirement when timeline idles")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org # v5.5
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230302120820.48740-1-janusz.krzysztofik@linux.intel.com
(cherry picked from commit 506006055769b10d1b2b4e22f636f3b45e0e9fc7)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

show more ...

drm/i915/active: Fix misuse of non-idle barriers as fence trackers

Users reported oopses on list corruptions when using i915 perf with a
number of concurrently running graphics applications. Root c

drm/i915/active: Fix misuse of non-idle barriers as fence trackers

Users reported oopses on list corruptions when using i915 perf with a
number of concurrently running graphics applications. Root cause analysis
pointed at an issue in barrier processing code -- a race among perf open /
close replacing active barriers with perf requests on kernel context and
concurrent barrier preallocate / acquire operations performed during user
context first pin / last unpin.

When adding a request to a composite tracker, we try to reuse an existing
fence tracker, already allocated and registered with that composite. The
tracker we obtain may already track another fence, may be an idle barrier,
or an active barrier.

If the tracker we get occurs a non-idle barrier then we try to delete that
barrier from a list of barrier tasks it belongs to. However, while doing
that we don't respect return value from a function that performs the
barrier deletion. Should the deletion ever fail, we would end up reusing
the tracker still registered as a barrier task. Since the same structure
field is reused with both fence callback lists and barrier tasks list,
list corruptions would likely occur.

Barriers are now deleted from a barrier tasks list by temporarily removing
the list content, traversing that content with skip over the node to be
deleted, then populating the list back with the modified content. Should
that intentionally racy concurrent deletion attempts be not serialized,
one or more of those may fail because of the list being temporary empty.

Related code that ignores the results of barrier deletion was initially
introduced in v5.4 by commit d8af05ff38ae ("drm/i915: Allow sharing the
idle-barrier from other kernel requests"). However, all users of the
barrier deletion routine were apparently serialized at that time, then the
issue didn't exhibit itself. Results of git bisect with help of a newly
developed igt@gem_barrier_race@remote-request IGT test indicate that list
corruptions might start to appear after commit 311770173fac ("drm/i915/gt:
Schedule request retirement when timeline idles"), introduced in v5.5.

Respect results of barrier deletion attempts -- mark the barrier as idle
only if successfully deleted from the list. Then, before proceeding with
setting our fence as the one currently tracked, make sure that the tracker
we've got is not a non-idle barrier. If that check fails then don't use
that tracker but go back and try to acquire a new, usable one.

v3: use unlikely() to document what outcome we expect (Andi),
- fix bad grammar in commit description.
v2: no code changes,
- blame commit 311770173fac ("drm/i915/gt: Schedule request retirement
when timeline idles"), v5.5, not commit d8af05ff38ae ("drm/i915: Allow
sharing the idle-barrier from other kernel requests"), v5.4,
- reword commit description.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6333
Fixes: 311770173fac ("drm/i915/gt: Schedule request retirement when timeline idles")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org # v5.5
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230302120820.48740-1-janusz.krzysztofik@linux.intel.com

show more ...

drm/i915: Bump GT idling delay to 2 jiffies

In monitoring a transcode pipeline that is latency sensitive (it waits
between submitting frames, and each frame requires work on rcs/vcs/vecs
engines), i

drm/i915: Bump GT idling delay to 2 jiffies

In monitoring a transcode pipeline that is latency sensitive (it waits
between submitting frames, and each frame requires work on rcs/vcs/vecs
engines), it is found that it took longer than a single jiffy for it to
sustain its workload. Allowing an extra jiffy headroom for the userspace
prevents us from prematurely parking and having to exit powersaving
immediately.

Link: https://gitlab.freedesktop.org/drm/intel/-/issues/6284
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Karolina Drobnik <karolina.drobnik@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e37911ec087a9ce50630d6faf61fa2c0d5f96d44.1657289332.git.karolina.drobnik@intel.com

show more ...

drm/i915: Remove unused bits of i915_vma/active api

When reworking the code to move the eviction fence to the object,
the best code is removed code.

Remove some functions that are unused, and chang

drm/i915: Remove unused bits of i915_vma/active api

When reworking the code to move the eviction fence to the object,
the best code is removed code.

Remove some functions that are unused, and change the function definition
if it's only used in 1 place.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
[mlankhorst: Remove new use of i915_active_has_exclusive]
Link: https://patchwork.freedesktop.org/patch/msgid/20211216142749.1966107-2-maarten.lankhorst@linux.intel.com

show more ...

drm/i915: move i915_active slab to direct module init/exit

With the global kmem_cache shrink infrastructure gone there's nothing
special and we can convert them over.

I'm doing this split up into e

drm/i915: move i915_active slab to direct module init/exit

With the global kmem_cache shrink infrastructure gone there's nothing
special and we can convert them over.

I'm doing this split up into each patch because there's quite a bit of
noise with removing the static global.slab_cache to just a slab_cache.

v2: Make slab static (Jason, 0day)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727121037.2041102-2-daniel.vetter@ffwll.ch

show more ...

drm/i915: Ditch i915 globals shrink infrastructure

This essentially reverts

commit 84a1074920523430f9dc30ff907f4801b4820072
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed Jan 24 11:36:

drm/i915: Ditch i915 globals shrink infrastructure

This essentially reverts

commit 84a1074920523430f9dc30ff907f4801b4820072
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed Jan 24 11:36:08 2018 +0000

drm/i915: Shrink the GEM kmem_caches upon idling

mm/vmscan.c:do_shrink_slab() is a thing, if there's an issue with it
then we need to fix that there, not hand-roll our own slab shrinking
code in i915.

Also when this was added there was only one other caller of
kmem_cache_shrink (added 2005 to the acpi code). Now there's a 2nd one
outside of i915 code in a kunit test, which seems legit since that
wants to very carefully control what's in the kmem_cache. This out of
a total of over 500 calls to kmem_cache_create. This alone should have
been warning sign enough that we're doing something silly.

Noticed while reviewing a patch set from Jason to fix up some issues
in our i915_init() and i915_exit() module load/cleanup code. Now that
i915_globals.c isn't any different than normal init/exit functions, we
should convert them over to one unified table and remove
i915_globals.[hc] entirely.

v2: Improve commit message (Jason)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721183229.4136488-1-daniel.vetter@ffwll.ch

show more ...

drm/i915: Fix crash in auto_retire

The retire logic uses the 2 lower bits of the pointer to the retire
function to store flags. However, the auto_retire function is not
guaranteed to be aligned to a

drm/i915: Fix crash in auto_retire

The retire logic uses the 2 lower bits of the pointer to the retire
function to store flags. However, the auto_retire function is not
guaranteed to be aligned to a multiple of 4, which causes crashes as
we jump to the wrong address, for example like this:

2021-04-24T18:03:53.804300Z WARNING kernel: [ 516.876901] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
2021-04-24T18:03:53.804310Z WARNING kernel: [ 516.876906] CPU: 7 PID: 146 Comm: kworker/u16:6 Tainted: G U 5.4.105-13595-g3cd84167b2df #1
2021-04-24T18:03:53.804311Z WARNING kernel: [ 516.876907] Hardware name: Google Volteer2/Volteer2, BIOS Google_Volteer2.13672.76.0 02/22/2021
2021-04-24T18:03:53.804312Z WARNING kernel: [ 516.876911] Workqueue: events_unbound active_work
2021-04-24T18:03:53.804313Z WARNING kernel: [ 516.876914] RIP: 0010:auto_retire+0x1/0x20
2021-04-24T18:03:53.804314Z WARNING kernel: [ 516.876916] Code: e8 01 f2 ff ff eb 02 31 db 48 89 d8 5b 5d c3 0f 1f 44 00 00 55 48 89 e5 f0 ff 87 c8 00 00 00 0f 88 ab 47 4a 00 31 c0 5d c3 0f <1f> 44 00 00 55 48 89 e5 f0 ff 8f c8 00 00 00 0f 88 9a 47 4a 00 74
2021-04-24T18:03:53.804319Z WARNING kernel: [ 516.876918] RSP: 0018:ffff9b4d809fbe38 EFLAGS: 00010286
2021-04-24T18:03:53.804320Z WARNING kernel: [ 516.876919] RAX: 0000000000000007 RBX: ffff927915079600 RCX: 0000000000000007
2021-04-24T18:03:53.804320Z WARNING kernel: [ 516.876921] RDX: ffff9b4d809fbe40 RSI: 0000000000000286 RDI: ffff927915079600
2021-04-24T18:03:53.804321Z WARNING kernel: [ 516.876922] RBP: ffff9b4d809fbe68 R08: 8080808080808080 R09: fefefefefefefeff
2021-04-24T18:03:53.804321Z WARNING kernel: [ 516.876924] R10: 0000000000000010 R11: ffffffff92e44bd8 R12: ffff9279150796a0
2021-04-24T18:03:53.804322Z WARNING kernel: [ 516.876925] R13: ffff92791c368180 R14: ffff927915079640 R15: 000000001c867605
2021-04-24T18:03:53.804323Z WARNING kernel: [ 516.876926] FS: 0000000000000000(0000) GS:ffff92791ffc0000(0000) knlGS:0000000000000000
2021-04-24T18:03:53.804323Z WARNING kernel: [ 516.876928] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2021-04-24T18:03:53.804324Z WARNING kernel: [ 516.876929] CR2: 0000239514955000 CR3: 00000007f82da001 CR4: 0000000000760ee0
2021-04-24T18:03:53.804325Z WARNING kernel: [ 516.876930] PKRU: 55555554
2021-04-24T18:03:53.804325Z WARNING kernel: [ 516.876931] Call Trace:
2021-04-24T18:03:53.804326Z WARNING kernel: [ 516.876935] __active_retire+0x77/0xcf
2021-04-24T18:03:53.804326Z WARNING kernel: [ 516.876939] process_one_work+0x1da/0x394
2021-04-24T18:03:53.804327Z WARNING kernel: [ 516.876941] worker_thread+0x216/0x375
2021-04-24T18:03:53.804327Z WARNING kernel: [ 516.876944] kthread+0x147/0x156
2021-04-24T18:03:53.804335Z WARNING kernel: [ 516.876946] ? pr_cont_work+0x58/0x58
2021-04-24T18:03:53.804335Z WARNING kernel: [ 516.876948] ? kthread_blkcg+0x2e/0x2e
2021-04-24T18:03:53.804336Z WARNING kernel: [ 516.876950] ret_from_fork+0x1f/0x40
2021-04-24T18:03:53.804336Z WARNING kernel: [ 516.876952] Modules linked in: cdc_mbim cdc_ncm cdc_wdm xt_cgroup rfcomm cmac algif_hash algif_skcipher af_alg xt_MASQUERADE uinput snd_soc_rt5682_sdw snd_soc_rt5682 snd_soc_max98373_sdw snd_soc_max98373 snd_soc_rl6231 regmap_sdw snd_soc_sof_sdw snd_soc_hdac_hdmi snd_soc_dmic snd_hda_codec_hdmi snd_sof_pci snd_sof_intel_hda_common intel_ipu6_psys snd_sof_xtensa_dsp soundwire_intel soundwire_generic_allocation soundwire_cadence snd_sof_intel_hda snd_sof snd_soc_hdac_hda snd_soc_acpi_intel_match snd_soc_acpi snd_hda_ext_core soundwire_bus snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core intel_ipu6_isys videobuf2_dma_contig videobuf2_v4l2 videobuf2_common videobuf2_memops mei_hdcp intel_ipu6 ov2740 ov8856 at24 sx9310 dw9768 v4l2_fwnode cros_ec_typec intel_pmc_mux roles acpi_als typec fuse iio_trig_sysfs cros_ec_light_prox cros_ec_lid_angle cros_ec_sensors cros_ec_sensors_core industrialio_triggered_buffer cros_ec_sensors_ring kfifo_buf industrialio cros_ec_sensorhub
2021-04-24T18:03:53.804337Z WARNING kernel: [ 516.876972] cdc_ether usbnet iwlmvm lzo_rle lzo_compress iwl7000_mac80211 iwlwifi zram cfg80211 r8152 mii btusb btrtl btintel btbcm bluetooth ecdh_generic ecc joydev
2021-04-24T18:03:53.804337Z EMERG kernel: [ 516.879169] gsmi: Log Shutdown Reason 0x03

This change fixes this by aligning the function.

Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
Fixes: 229007e02d69 ("drm/i915: Wrap i915_active in a simple kreffed struct")
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210429031021.1218091-1-marcheu@chromium.org
(cherry picked from commit ca419f407b43cc89942ebc297c7a63d94abbcae4)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

show more ...

drm/i915: drop the __i915_active_call pointer packing

We use some of the lower bits of the retire function pointer for
potential flags, which is quite thorny, since the caller needs to
remember to g

drm/i915: drop the __i915_active_call pointer packing

We use some of the lower bits of the retire function pointer for
potential flags, which is quite thorny, since the caller needs to
remember to give the function the correct alignment with
__i915_active_call, otherwise we might incorrectly unpack the pointer
and jump to some garbage address later. Instead of all this let's just
pass the flags along as a separate parameter.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
References: ca419f407b43 ("drm/i915: Fix crash in auto_retire")
References: d8e44e4dd221 ("drm/i915/overlay: Fix active retire callback alignment")
References: fd5f262db118 ("drm/i915/selftests: Fix active retire callback alignment")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210504164136.96456-1-matthew.auld@intel.com

show more ...

drm/i915: Fix crash in auto_retire

The retire logic uses the 2 lower bits of the pointer to the retire
function to store flags. However, the auto_retire function is not
guaranteed to be aligned to a

drm/i915: Fix crash in auto_retire

The retire logic uses the 2 lower bits of the pointer to the retire
function to store flags. However, the auto_retire function is not
guaranteed to be aligned to a multiple of 4, which causes crashes as
we jump to the wrong address, for example like this:

2021-04-24T18:03:53.804300Z WARNING kernel: [ 516.876901] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
2021-04-24T18:03:53.804310Z WARNING kernel: [ 516.876906] CPU: 7 PID: 146 Comm: kworker/u16:6 Tainted: G U 5.4.105-13595-g3cd84167b2df #1
2021-04-24T18:03:53.804311Z WARNING kernel: [ 516.876907] Hardware name: Google Volteer2/Volteer2, BIOS Google_Volteer2.13672.76.0 02/22/2021
2021-04-24T18:03:53.804312Z WARNING kernel: [ 516.876911] Workqueue: events_unbound active_work
2021-04-24T18:03:53.804313Z WARNING kernel: [ 516.876914] RIP: 0010:auto_retire+0x1/0x20
2021-04-24T18:03:53.804314Z WARNING kernel: [ 516.876916] Code: e8 01 f2 ff ff eb 02 31 db 48 89 d8 5b 5d c3 0f 1f 44 00 00 55 48 89 e5 f0 ff 87 c8 00 00 00 0f 88 ab 47 4a 00 31 c0 5d c3 0f <1f> 44 00 00 55 48 89 e5 f0 ff 8f c8 00 00 00 0f 88 9a 47 4a 00 74
2021-04-24T18:03:53.804319Z WARNING kernel: [ 516.876918] RSP: 0018:ffff9b4d809fbe38 EFLAGS: 00010286
2021-04-24T18:03:53.804320Z WARNING kernel: [ 516.876919] RAX: 0000000000000007 RBX: ffff927915079600 RCX: 0000000000000007
2021-04-24T18:03:53.804320Z WARNING kernel: [ 516.876921] RDX: ffff9b4d809fbe40 RSI: 0000000000000286 RDI: ffff927915079600
2021-04-24T18:03:53.804321Z WARNING kernel: [ 516.876922] RBP: ffff9b4d809fbe68 R08: 8080808080808080 R09: fefefefefefefeff
2021-04-24T18:03:53.804321Z WARNING kernel: [ 516.876924] R10: 0000000000000010 R11: ffffffff92e44bd8 R12: ffff9279150796a0
2021-04-24T18:03:53.804322Z WARNING kernel: [ 516.876925] R13: ffff92791c368180 R14: ffff927915079640 R15: 000000001c867605
2021-04-24T18:03:53.804323Z WARNING kernel: [ 516.876926] FS: 0000000000000000(0000) GS:ffff92791ffc0000(0000) knlGS:0000000000000000
2021-04-24T18:03:53.804323Z WARNING kernel: [ 516.876928] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2021-04-24T18:03:53.804324Z WARNING kernel: [ 516.876929] CR2: 0000239514955000 CR3: 00000007f82da001 CR4: 0000000000760ee0
2021-04-24T18:03:53.804325Z WARNING kernel: [ 516.876930] PKRU: 55555554
2021-04-24T18:03:53.804325Z WARNING kernel: [ 516.876931] Call Trace:
2021-04-24T18:03:53.804326Z WARNING kernel: [ 516.876935] __active_retire+0x77/0xcf
2021-04-24T18:03:53.804326Z WARNING kernel: [ 516.876939] process_one_work+0x1da/0x394
2021-04-24T18:03:53.804327Z WARNING kernel: [ 516.876941] worker_thread+0x216/0x375
2021-04-24T18:03:53.804327Z WARNING kernel: [ 516.876944] kthread+0x147/0x156
2021-04-24T18:03:53.804335Z WARNING kernel: [ 516.876946] ? pr_cont_work+0x58/0x58
2021-04-24T18:03:53.804335Z WARNING kernel: [ 516.876948] ? kthread_blkcg+0x2e/0x2e
2021-04-24T18:03:53.804336Z WARNING kernel: [ 516.876950] ret_from_fork+0x1f/0x40
2021-04-24T18:03:53.804336Z WARNING kernel: [ 516.876952] Modules linked in: cdc_mbim cdc_ncm cdc_wdm xt_cgroup rfcomm cmac algif_hash algif_skcipher af_alg xt_MASQUERADE uinput snd_soc_rt5682_sdw snd_soc_rt5682 snd_soc_max98373_sdw snd_soc_max98373 snd_soc_rl6231 regmap_sdw snd_soc_sof_sdw snd_soc_hdac_hdmi snd_soc_dmic snd_hda_codec_hdmi snd_sof_pci snd_sof_intel_hda_common intel_ipu6_psys snd_sof_xtensa_dsp soundwire_intel soundwire_generic_allocation soundwire_cadence snd_sof_intel_hda snd_sof snd_soc_hdac_hda snd_soc_acpi_intel_match snd_soc_acpi snd_hda_ext_core soundwire_bus snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core intel_ipu6_isys videobuf2_dma_contig videobuf2_v4l2 videobuf2_common videobuf2_memops mei_hdcp intel_ipu6 ov2740 ov8856 at24 sx9310 dw9768 v4l2_fwnode cros_ec_typec intel_pmc_mux roles acpi_als typec fuse iio_trig_sysfs cros_ec_light_prox cros_ec_lid_angle cros_ec_sensors cros_ec_sensors_core industrialio_triggered_buffer cros_ec_sensors_ring kfifo_buf industrialio cros_ec_sensorhub
2021-04-24T18:03:53.804337Z WARNING kernel: [ 516.876972] cdc_ether usbnet iwlmvm lzo_rle lzo_compress iwl7000_mac80211 iwlwifi zram cfg80211 r8152 mii btusb btrtl btintel btbcm bluetooth ecdh_generic ecc joydev
2021-04-24T18:03:53.804337Z EMERG kernel: [ 516.879169] gsmi: Log Shutdown Reason 0x03

This change fixes this by aligning the function.

Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
Fixes: 229007e02d69 ("drm/i915: Wrap i915_active in a simple kreffed struct")
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210429031021.1218091-1-marcheu@chromium.org

show more ...

drm/i915: make lockdep slightly happier about execbuf.

As soon as we install fences, we should stop allocating memory
in order to prevent any potential deadlocks.

This is required later on, when we

drm/i915: make lockdep slightly happier about execbuf.

As soon as we install fences, we should stop allocating memory
in order to prevent any potential deadlocks.

This is required later on, when we start adding support for
dma-fence annotations.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-11-maarten.lankhorst@linux.intel.com

show more ...

drm/i915: Always flush the active worker before returning from the wait

The first thing the active retirement worker does is decrement the
i915_active count.

The first thing we do during i915_activ

drm/i915: Always flush the active worker before returning from the wait

The first thing the active retirement worker does is decrement the
i915_active count.

The first thing we do during i915_active_wait is try to increment the
i915_active count, but only if already active [non-zero].

The wait may see that the retirement is already started and so marked the
i915_active as idle, and skip waiting for the retirement handler.
However, the caller of i915_active_wait may immediately free the
i915_active upon returning (e.g. i915_vma_destroy) so we must not return
before the concurrent access from the worker is completed. We must
always flush the worker.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2473
Fixes: 274cbf20fd10 ("drm/i915: Push the i915_active.retire into a worker")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: <stable@vger.kernel.org> # v5.5+
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210121232807.16618-1-chris@chris-wilson.co.uk
(cherry picked from commit 977a372e972cb42799746c284035a33c64ebace9)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

show more ...

drm/i915: Use cmpxchg64 for 32b compatilibity

By using the double wide cmpxchg64 on 32bit, we can use the same
algorithm on both 32/64b systems.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.u

drm/i915: Use cmpxchg64 for 32b compatilibity

By using the double wide cmpxchg64 on 32bit, we can use the same
algorithm on both 32/64b systems.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201211110310.22740-1-chris@chris-wilson.co.uk

show more ...

drm/i915: Fix crash in auto_retire

commit 402be8a101190969fc7ff122d07e262df86e132b upstream.

The retire logic uses the 2 lower bits of the pointer to the retire
function to store flags. However, th

drm/i915: Fix crash in auto_retire

commit 402be8a101190969fc7ff122d07e262df86e132b upstream.

The retire logic uses the 2 lower bits of the pointer to the retire
function to store flags. However, the auto_retire function is not
guaranteed to be aligned to a multiple of 4, which causes crashes as
we jump to the wrong address, for example like this:

2021-04-24T18:03:53.804300Z WARNING kernel: [ 516.876901] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
2021-04-24T18:03:53.804310Z WARNING kernel: [ 516.876906] CPU: 7 PID: 146 Comm: kworker/u16:6 Tainted: G U 5.4.105-13595-g3cd84167b2df #1
2021-04-24T18:03:53.804311Z WARNING kernel: [ 516.876907] Hardware name: Google Volteer2/Volteer2, BIOS Google_Volteer2.13672.76.0 02/22/2021
2021-04-24T18:03:53.804312Z WARNING kernel: [ 516.876911] Workqueue: events_unbound active_work
2021-04-24T18:03:53.804313Z WARNING kernel: [ 516.876914] RIP: 0010:auto_retire+0x1/0x20
2021-04-24T18:03:53.804314Z WARNING kernel: [ 516.876916] Code: e8 01 f2 ff ff eb 02 31 db 48 89 d8 5b 5d c3 0f 1f 44 00 00 55 48 89 e5 f0 ff 87 c8 00 00 00 0f 88 ab 47 4a 00 31 c0 5d c3 0f <1f> 44 00 00 55 48 89 e5 f0 ff 8f c8 00 00 00 0f 88 9a 47 4a 00 74
2021-04-24T18:03:53.804319Z WARNING kernel: [ 516.876918] RSP: 0018:ffff9b4d809fbe38 EFLAGS: 00010286
2021-04-24T18:03:53.804320Z WARNING kernel: [ 516.876919] RAX: 0000000000000007 RBX: ffff927915079600 RCX: 0000000000000007
2021-04-24T18:03:53.804320Z WARNING kernel: [ 516.876921] RDX: ffff9b4d809fbe40 RSI: 0000000000000286 RDI: ffff927915079600
2021-04-24T18:03:53.804321Z WARNING kernel: [ 516.876922] RBP: ffff9b4d809fbe68 R08: 8080808080808080 R09: fefefefefefefeff
2021-04-24T18:03:53.804321Z WARNING kernel: [ 516.876924] R10: 0000000000000010 R11: ffffffff92e44bd8 R12: ffff9279150796a0
2021-04-24T18:03:53.804322Z WARNING kernel: [ 516.876925] R13: ffff92791c368180 R14: ffff927915079640 R15: 000000001c867605
2021-04-24T18:03:53.804323Z WARNING kernel: [ 516.876926] FS: 0000000000000000(0000) GS:ffff92791ffc0000(0000) knlGS:0000000000000000
2021-04-24T18:03:53.804323Z WARNING kernel: [ 516.876928] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2021-04-24T18:03:53.804324Z WARNING kernel: [ 516.876929] CR2: 0000239514955000 CR3: 00000007f82da001 CR4: 0000000000760ee0
2021-04-24T18:03:53.804325Z WARNING kernel: [ 516.876930] PKRU: 55555554
2021-04-24T18:03:53.804325Z WARNING kernel: [ 516.876931] Call Trace:
2021-04-24T18:03:53.804326Z WARNING kernel: [ 516.876935] __active_retire+0x77/0xcf
2021-04-24T18:03:53.804326Z WARNING kernel: [ 516.876939] process_one_work+0x1da/0x394
2021-04-24T18:03:53.804327Z WARNING kernel: [ 516.876941] worker_thread+0x216/0x375
2021-04-24T18:03:53.804327Z WARNING kernel: [ 516.876944] kthread+0x147/0x156
2021-04-24T18:03:53.804335Z WARNING kernel: [ 516.876946] ? pr_cont_work+0x58/0x58
2021-04-24T18:03:53.804335Z WARNING kernel: [ 516.876948] ? kthread_blkcg+0x2e/0x2e
2021-04-24T18:03:53.804336Z WARNING kernel: [ 516.876950] ret_from_fork+0x1f/0x40
2021-04-24T18:03:53.804336Z WARNING kernel: [ 516.876952] Modules linked in: cdc_mbim cdc_ncm cdc_wdm xt_cgroup rfcomm cmac algif_hash algif_skcipher af_alg xt_MASQUERADE uinput snd_soc_rt5682_sdw snd_soc_rt5682 snd_soc_max98373_sdw snd_soc_max98373 snd_soc_rl6231 regmap_sdw snd_soc_sof_sdw snd_soc_hdac_hdmi snd_soc_dmic snd_hda_codec_hdmi snd_sof_pci snd_sof_intel_hda_common intel_ipu6_psys snd_sof_xtensa_dsp soundwire_intel soundwire_generic_allocation soundwire_cadence snd_sof_intel_hda snd_sof snd_soc_hdac_hda snd_soc_acpi_intel_match snd_soc_acpi snd_hda_ext_core soundwire_bus snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core intel_ipu6_isys videobuf2_dma_contig videobuf2_v4l2 videobuf2_common videobuf2_memops mei_hdcp intel_ipu6 ov2740 ov8856 at24 sx9310 dw9768 v4l2_fwnode cros_ec_typec intel_pmc_mux roles acpi_als typec fuse iio_trig_sysfs cros_ec_light_prox cros_ec_lid_angle cros_ec_sensors cros_ec_sensors_core industrialio_triggered_buffer cros_ec_sensors_ring kfifo_buf industrialio cros_ec_sensorhub
2021-04-24T18:03:53.804337Z WARNING kernel: [ 516.876972] cdc_ether usbnet iwlmvm lzo_rle lzo_compress iwl7000_mac80211 iwlwifi zram cfg80211 r8152 mii btusb btrtl btintel btbcm bluetooth ecdh_generic ecc joydev
2021-04-24T18:03:53.804337Z EMERG kernel: [ 516.879169] gsmi: Log Shutdown Reason 0x03

This change fixes this by aligning the function.

Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
Fixes: 229007e02d69 ("drm/i915: Wrap i915_active in a simple kreffed struct")
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210429031021.1218091-1-marcheu@chromium.org
(cherry picked from commit ca419f407b43cc89942ebc297c7a63d94abbcae4)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

drm/i915: Always flush the active worker before returning from the wait

commit f6e98a1809faa02f40e0d089d6cfc1aa372a34c0 upstream.

The first thing the active retirement worker does is decrement the

drm/i915: Always flush the active worker before returning from the wait

commit f6e98a1809faa02f40e0d089d6cfc1aa372a34c0 upstream.

The first thing the active retirement worker does is decrement the
i915_active count.

The first thing we do during i915_active_wait is try to increment the
i915_active count, but only if already active [non-zero].

The wait may see that the retirement is already started and so marked the
i915_active as idle, and skip waiting for the retirement handler.
However, the caller of i915_active_wait may immediately free the
i915_active upon returning (e.g. i915_vma_destroy) so we must not return
before the concurrent access from the worker is completed. We must
always flush the worker.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2473
Fixes: 274cbf20fd10 ("drm/i915: Push the i915_active.retire into a worker")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: <stable@vger.kernel.org> # v5.5+
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210121232807.16618-1-chris@chris-wilson.co.uk
(cherry picked from commit 977a372e972cb42799746c284035a33c64ebace9)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

treewide: Make all debug_obj_descriptors const

This should make it harder for the kernel to corrupt the debug object
descriptor, used to call functions to fixup state and track debug objects,
by mov

treewide: Make all debug_obj_descriptors const

This should make it harder for the kernel to corrupt the debug object
descriptor, used to call functions to fixup state and track debug objects,
by moving the structure to read-only memory.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200815004027.2046113-3-swboyd@chromium.org

show more ...

drm/i915: Reduce locking around i915_active_acquire_preallocate_barrier()

As the conversion between idle-barrier and full i915_active_fence is
already serialised by explicit memory barriers, we can

drm/i915: Reduce locking around i915_active_acquire_preallocate_barrier()

As the conversion between idle-barrier and full i915_active_fence is
already serialised by explicit memory barriers, we can reduce the
spinlock in i915_active_acquire_preallocate_barrier() for finding an
idle-barrier to reuse to an RCU read lock to ensure the fence remains
valid, only taking the spinlock for the update of the rbtree itself.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-6-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

drm/i915: Make the stale cached active node available for any timeline

Rather than require the next timeline after idling to match the MRU
before idling, reset the index on the node and allow it to

drm/i915: Make the stale cached active node available for any timeline

Rather than require the next timeline after idling to match the MRU
before idling, reset the index on the node and allow it to match the
first request. However, this requires cmpxchg(u64) and so is not trivial
on 32b, so for compatibility we just fallback to keeping the cached node
pointing to the MRU timeline.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-5-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

drm/i915: Keep the most recently used active-fence upon discard

Whenever an i915_active idles, we prune its tree of old fence slots to
prevent a gradual leak should it be used to track many, many ti

drm/i915: Keep the most recently used active-fence upon discard

Whenever an i915_active idles, we prune its tree of old fence slots to
prevent a gradual leak should it be used to track many, many timelines.
The downside is that we then have to frequently reallocate the rbtree.
A compromise is that we keep the most recently used fence slot, and
reuse that for the next active reference as that is the most likely
timeline to be reused.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-4-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

drm/i915: Export a preallocate variant of i915_active_acquire()

Sometimes we have to be very careful not to allocate underneath a mutex
(or spinlock) and yet still want to track activity. Enter
i915

drm/i915: Export a preallocate variant of i915_active_acquire()

Sometimes we have to be very careful not to allocate underneath a mutex
(or spinlock) and yet still want to track activity. Enter
i915_active_acquire_for_context(). This raises the activity counter on
i915_active prior to use and ensures that the fence-tree contains a slot
for the context.

v2: Refactor active_lookup() so it can be called again before/after
locking to resolve contention. Since we protect the rbtree until we
idle, we can do a lockfree lookup, with the caveat that if another
thread performs a concurrent insertion, the rotations from the insert
may cause us to not find our target. A second pass holding the treelock
will find the target if it exists, or the place to perform our
insertion.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-3-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

drm/i915: Skip taking acquire mutex for no ref->active callback

If no active callback is defined for i915_active, we do not need to
serialise its enabling with the mutex. We still do only want to ca

drm/i915: Skip taking acquire mutex for no ref->active callback

If no active callback is defined for i915_active, we do not need to
serialise its enabling with the mutex. We still do only want to call the
debug activate once, and must still serialise with a concurrent retire.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-2-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

drm/i915: Fix wrong return value

In function i915_active_acquire_preallocate_barrier(), not all
paths have the return value set correctly, and in case of memory
allocation failure, a negative error

drm/i915: Fix wrong return value

In function i915_active_acquire_preallocate_barrier(), not all
paths have the return value set correctly, and in case of memory
allocation failure, a negative error code should be returned.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200802115655.25568-1-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

show more ...