drm/sched: fix null-ptr-deref in init entity

The bug can be triggered by sending an amdgpu_cs_wait_ioctl
to the AMDGPU DRM driver on any ASICs with valid context.
The bug was reported by Joonkyo Jung <joonkyoj@yonsei.ac.kr>.
For example the following code:

static void Syzkaller2(int fd)
{
union drm_amdgpu_ctx arg1;
union drm_amdgpu_wait_cs arg2;

arg1.in.op = AMDGPU_CTX_OP_ALLOC_CTX;
ret = drmIoctl(fd, 0x140106442 /* amdgpu_ctx_ioctl */, &arg1);

arg2.in.handle = 0x0;
arg2.in.timeout = 0x2000000000000;
arg2.in.ip_type = AMD_IP_VPE /* 0x9 */;
arg2->in.ip_instance = 0x0;
arg2.in.ring = 0x0;
arg2.in.ctx_id = arg1.out.alloc.ctx_id;

drmIoctl(fd, 0xc0206449 /* AMDGPU_WAIT_CS * /, &arg2);
}

The ioctl AMDGPU_WAIT_CS without previously submitted job could be assumed that
the error should be returned, but the following commit 1decbf6bb0b4dc56c9da6c5e57b994ebfc2be3aa
modified the logic and allowed to have sched_rq equal to NULL.

As a result when there is no job the ioctl AMDGPU_WAIT_CS returns success.
The change fixes null-ptr-deref in init entity and the stack below demonstrates
the error condition:

[ +0.000007] BUG: kernel NULL pointer dereference, address: 0000000000000028
[ +0.007086] #PF: supervisor read access in kernel mode
[ +0.005234] #PF: error_code(0x0000) - not-present page
[ +0.005232] PGD 0 P4D 0
[ +0.002501] Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ +0.005034] CPU: 10 PID: 9229 Comm: amd_basic Tainted: G B W L 6.7.0+ #4
[ +0.007797] Hardware name: ASUS System Product Name/ROG STRIX B550-F GAMING (WI-FI), BIOS 1401 12/03/2020
[ +0.009798] RIP: 0010:drm_sched_entity_init+0x2d3/0x420 [gpu_sched]
[ +0.006426] Code: 80 00 00 00 00 00 00 00 e8 1a 81 82 e0 49 89 9c 24 c0 00 00 00 4c 89 ef e8 4a 80 82 e0 49 8b 5d 00 48 8d 7b 28 e8 3d 80 82 e0 <48> 83 7b 28 00 0f 84 28 01 00 00 4d 8d ac 24 98 00 00 00 49 8d 5c
[ +0.019094] RSP: 0018:ffffc90014c1fa40 EFLAGS: 00010282
[ +0.005237] RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8113f3fa
[ +0.007326] RDX: fffffbfff0a7889d RSI: 0000000000000008 RDI: ffffffff853c44e0
[ +0.007264] RBP: ffffc90014c1fa80 R08: 0000000000000001 R09: fffffbfff0a7889c
[ +0.007266] R10: ffffffff853c44e7 R11: 0000000000000001 R12: ffff8881a719b010
[ +0.007263] R13: ffff88810d412748 R14: 0000000000000002 R15: 0000000000000000
[ +0.007264] FS: 00007ffff7045540(0000) GS:ffff8883cc900000(0000) knlGS:0000000000000000
[ +0.008236] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ +0.005851] CR2: 0000000000000028 CR3: 000000011912e000 CR4: 0000000000350ef0
[ +0.007175] Call Trace:
[ +0.002561] <TASK>
[ +0.002141] ? show_regs+0x6a/0x80
[ +0.003473] ? __die+0x25/0x70
[ +0.003124] ? page_fault_oops+0x214/0x720
[ +0.004179] ? preempt_count_sub+0x18/0xc0
[ +0.004093] ? __pfx_page_fault_oops+0x10/0x10
[ +0.004590] ? srso_return_thunk+0x5/0x5f
[ +0.004000] ? vprintk_default+0x1d/0x30
[ +0.004063] ? srso_return_thunk+0x5/0x5f
[ +0.004087] ? vprintk+0x5c/0x90
[ +0.003296] ? drm_sched_entity_init+0x2d3/0x420 [gpu_sched]
[ +0.005807] ? srso_return_thunk+0x5/0x5f
[ +0.004090] ? _printk+0xb3/0xe0
[ +0.003293] ? __pfx__printk+0x10/0x10
[ +0.003735] ? asm_sysvec_apic_timer_interrupt+0x1b/0x20
[ +0.005482] ? do_user_addr_fault+0x345/0x770
[ +0.004361] ? exc_page_fault+0x64/0xf0
[ +0.003972] ? asm_exc_page_fault+0x27/0x30
[ +0.004271] ? add_taint+0x2a/0xa0
[ +0.003476] ? drm_sched_entity_init+0x2d3/0x420 [gpu_sched]
[ +0.005812] amdgpu_ctx_get_entity+0x3f9/0x770 [amdgpu]
[ +0.009530] ? finish_task_switch.isra.0+0x129/0x470
[ +0.005068] ? __pfx_amdgpu_ctx_get_entity+0x10/0x10 [amdgpu]
[ +0.010063] ? __kasan_check_write+0x14/0x20
[ +0.004356] ? srso_return_thunk+0x5/0x5f
[ +0.004001] ? mutex_unlock+0x81/0xd0
[ +0.003802] ? srso_return_thunk+0x5/0x5f
[ +0.004096] amdgpu_cs_wait_ioctl+0xf6/0x270 [amdgpu]
[ +0.009355] ? __pfx_amdgpu_cs_wait_ioctl+0x10/0x10 [amdgpu]
[ +0.009981] ? srso_return_thunk+0x5/0x5f
[ +0.004089] ? srso_return_thunk+0x5/0x5f
[ +0.004090] ? __srcu_read_lock+0x20/0x50
[ +0.004096] drm_ioctl_kernel+0x140/0x1f0 [drm]
[ +0.005080] ? __pfx_amdgpu_cs_wait_ioctl+0x10/0x10 [amdgpu]
[ +0.009974] ? __pfx_drm_ioctl_kernel+0x10/0x10 [drm]
[ +0.005618] ? srso_return_thunk+0x5/0x5f
[ +0.004088] ? __kasan_check_write+0x14/0x20
[ +0.004357] drm_ioctl+0x3da/0x730 [drm]
[ +0.004461] ? __pfx_amdgpu_cs_wait_ioctl+0x10/0x10 [amdgpu]
[ +0.009979] ? __pfx_drm_ioctl+0x10/0x10 [drm]
[ +0.004993] ? srso_return_thunk+0x5/0x5f
[ +0.004090] ? __kasan_check_write+0x14/0x20
[ +0.004356] ? srso_return_thunk+0x5/0x5f
[ +0.004090] ? _raw_spin_lock_irqsave+0x99/0x100
[ +0.004712] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ +0.005063] ? __pfx_arch_do_signal_or_restart+0x10/0x10
[ +0.005477] ? srso_return_thunk+0x5/0x5f
[ +0.004000] ? preempt_count_sub+0x18/0xc0
[ +0.004237] ? srso_return_thunk+0x5/0x5f
[ +0.004090] ? _raw_spin_unlock_irqrestore+0x27/0x50
[ +0.005069] amdgpu_drm_ioctl+0x7e/0xe0 [amdgpu]
[ +0.008912] __x64_sys_ioctl+0xcd/0x110
[ +0.003918] do_syscall_64+0x5f/0xe0
[ +0.003649] ? noist_exc_debug+0xe6/0x120
[ +0.004095] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ +0.005150] RIP: 0033:0x7ffff7b1a94f
[ +0.003647] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 64 48 2b 04 25 28 00
[ +0.019097] RSP: 002b:00007fffffffe0a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ +0.007708] RAX: ffffffffffffffda RBX: 000055555558b360 RCX: 00007ffff7b1a94f
[ +0.007176] RDX: 000055555558b360 RSI: 00000000c0206449 RDI: 0000000000000003
[ +0.007326] RBP: 00000000c0206449 R08: 000055555556ded0 R09: 000000007fffffff
[ +0.007176] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffffffe5d8
[ +0.007238] R13: 0000000000000003 R14: 000055555555cba8 R15: 00007ffff7ffd040
[ +0.007250] </TASK>

v2: Reworked check to guard against null ptr deref and added helpful comments
(Christian)

Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Cc: Joonkyo Jung <joonkyoj@yonsei.ac.kr>
Cc: Dokyung Song <dokyungs@yonsei.ac.kr>
Cc: <jisoo.jang@yonsei.ac.kr>
Cc: <yw9865@yonsei.ac.kr>
Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Fixes: 56e449603f0a ("drm/sched: Convert the GPU scheduler to variable number of run-queues")
Link: https://patchwork.freedesktop.org/patch/msgid/20240315023926.343164-1-vitaly.prosyak@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>

drm/sched: Reverse run-queue priority enumeration

Reverse run-queue priority enumeration such that the higest priority is now 0,
and for each consecutive integer the prioirty diminishes.

Run-queues correspond to priorities. To an external observer a scheduler
created with a single run-queue, and another created with
DRM_SCHED_PRIORITY_COUNT number of run-queues, should always schedule
sched->sched_rq[0] with the same "priority", as that index run-queue exists in
both schedulers, i.e. a scheduler with one run-queue or many. This patch makes
it so.

In other words, the "priority" of sched->sched_rq[n], n >= 0, is the same for
any scheduler created with any allowable number of run-queues (priorities), 0
to DRM_SCHED_PRIORITY_COUNT.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231124052752.6915-6-ltuikov89@gmail.com

drm/sched: Rename priority MIN to LOW

Rename DRM_SCHED_PRIORITY_MIN to DRM_SCHED_PRIORITY_LOW.

This mirrors DRM_SCHED_PRIORITY_HIGH, for a list of DRM scheduler priorities
in ascending order,
DRM_SCHED_PRIORITY_LOW,
DRM_SCHED_PRIORITY_NORMAL,
DRM_SCHED_PRIORITY_HIGH,
DRM_SCHED_PRIORITY_KERNEL.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231124052752.6915-5-ltuikov89@gmail.com

drm/sched: Fix bounds limiting when given a malformed entity

If we're given a malformed entity in drm_sched_entity_init()--shouldn't
happen, but we verify--with out-of-bounds priority value, we set it to an
allowed value. Fix the expression which sets this limit.

Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Fixes: 56e449603f0ac5 ("drm/sched: Convert the GPU scheduler to variable number of run-queues")
Link: https://patchwork.freedesktop.org/patch/msgid/20231123122422.167832-2-ltuikov89@gmail.com
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/dbb91dbe-ef77-4d79-aaf9-2adb171c1d7a@amd.com

drm/sched: Qualify drm_sched_wakeup() by drm_sched_entity_is_ready()

Don't "wake up" the GPU scheduler unless the entity is ready, as well as we
can queue to the scheduler, i.e. there is no point in waking up the scheduler
for the entity unless the entity is ready.

Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Fixes: bc8d6a9df99038 ("drm/sched: Don't disturb the entity when in RR-mode scheduling")
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231110000123.72565-2-ltuikov89@gmail.com

drm/sched: Drop suffix from drm_sched_wakeup_if_can_queue

Because a) helper is exported to other parts of the scheduler and
b) there isn't a plain drm_sched_wakeup to begin with, I think we can
drop the suffix and by doing so separate the intimiate knowledge
between the scheduler components a bit better.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102105538.391648-6-tvrtko.ursulin@linux.intel.com
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>

drm/sched: Convert the GPU scheduler to variable number of run-queues

The GPU scheduler has now a variable number of run-queues, which are set up at
drm_sched_init() time. This way, each driver announces how many run-queues it
requires (supports) per each GPU scheduler it creates. Note, that run-queues
correspond to scheduler "priorities", thus if the number of run-queues is set
to 1 at drm_sched_init(), then that scheduler supports a single run-queue,
i.e. single "priority". If a driver further sets a single entity per
run-queue, then this creates a 1-to-1 correspondence between a scheduler and
a scheduled entity.

Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Qiang Yu <yuq825@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Emma Anholt <emma@anholt.net>
Cc: etnaviv@lists.freedesktop.org
Cc: lima@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20231023032251.164775-1-luben.tuikov@amd.com

drm/sched: Make sure we wait for all dependencies in kill_jobs_cb()

drm_sched_entity_kill_jobs_cb() logic is omitting the last fence popped
from the dependency array that was waited upon before
drm_sched_entity_kill() was called (drm_sched_entity::dependency field),
so we're basically waiting for all dependencies except one.

In theory, this wait shouldn't be needed because resources should have
their users registered to the dma_resv object, thus guaranteeing that
future jobs wanting to access these resources wait on all the previous
users (depending on the access type, of course). But we want to keep
these explicit waits in the kill entity path just in case.

Let's make sure we keep all dependencies in the array in
drm_sched_job_dependency(), so we can iterate over the array and wait
in drm_sched_entity_kill_jobs_cb().

We also make sure we wait on drm_sched_fence::finished if we were
originally asked to wait on drm_sched_fence::scheduled. In that case,
we assume the intent was to delegate the wait to the firmware/GPU or
rely on the pipelining done at the entity/scheduler level, but when
killing jobs, we really want to wait for completion not just scheduling.

v2:
- Don't evict deps in drm_sched_job_dependency()

v3:
- Always wait for drm_sched_fence::finished fences in
drm_sched_entity_kill_jobs_cb() when we see a sched_fence

v4:
- Fix commit message
- Fix a use-after-free bug

v5:
- Flag deps on which we should only wait for the scheduled event
at insertion time

v6:
- Back to v4 implementation
- Add Christian's R-b

Cc: Frank Binns <frank.binns@imgtec.com>
Cc: Sarah Walker <sarah.walker@imgtec.com>
Cc: Donald Robson <donald.robson@imgtec.com>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Suggested-by: "Christian König" <christian.koenig@amd.com>
Reviewed-by: "Christian König" <christian.koenig@amd.com>
Acked-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230619071921.3465992-1-boris.brezillon@collabora.com

drm/scheduler: avoid infinite loop if entity's dependency is a scheduled error fence

[Why]
drm_sched_entity_add_dependency_cb ignores the scheduled fence and return false.
If entity's dependency is a scheduler error fence and drm_sched_stop is called
due to TDR, drm_sched_entity_pop_job will wait for the dependency infinitely.

[How]
Do not wait or ignore the scheduled error fence, add drm_sched_entity_wakeup
callback for the dependency with scheduled error fence.

Signed-off-by: ZhenGuo Yin <zhenguo.yin@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/sched: Rename to drm_sched_wakeup_if_can_queue()

Rename drm_sched_wakeup() to drm_sched_wakeup_if_canqueue() since the former
is misleading, as it wakes up the GPU scheduler _only if_ more jobs can be
queued to the underlying hardware.

This distinction is important to make, since the wake conditional in the GPU
scheduler thread wakes up when other conditions are also true, e.g. when there
are jobs to be cleaned. For instance, a user might want to wake up the
scheduler only because there are more jobs to clean, but whether we can queue
more jobs is irrelevant.

v2: Separate "canqueue" to "can_queue". (Alex D.)

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://lore.kernel.org/r/20230517233550.377847-2-luben.tuikov@amd.com
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>

drm/scheduler: add drm_sched_entity_error and use rcu for last_scheduled

Switch to using RCU handling for the last scheduled job and add a
function to return the error code of it.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230420115752.31470-2-christian.koenig@amd.com

drm/scheduler: properly forward fence errors

When a hw fence is signaled with an error properly forward that to the
finished fence.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230420115752.31470-1-christian.koenig@amd.com

drm/scheduler: set entity to NULL in drm_sched_entity_pop_job()

It already happend a few times that patches slipped through which
implemented access to an entity through a job that was already removed
from the entities queue. Since jobs and entities might have different
lifecycles, this can potentially cause UAF bugs.

In order to make it obvious that a jobs entity pointer shouldn't be
accessed after drm_sched_entity_pop_job() was called successfully, set
the jobs entity pointer to NULL once the job is removed from the entity
queue.

Moreover, debugging a potential NULL pointer dereference is way easier
than potentially corrupted memory through a UAF.

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://lore.kernel.org/r/20230418100453.4433-1-dakr@redhat.com
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>

drm/scheduler: Fix UAF race in drm_sched_entity_push_job()

After a job is pushed into the queue, it is owned by the scheduler core
and may be freed at any time, so we can't write nor read the submit
timestamp after that point.

Fixes oopses observed with the drm/asahi driver, found with kASAN.

Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230406-scheduler-uaf-2-v1-1-972531cf0a81@asahilina.net
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>

drm/scheduler: Fix UAF race in drm_sched_entity_push_job()

After a job is pushed into the queue, it is owned by the scheduler core
and may be freed at any time, so we can't write nor read the submit
timestamp after that point.

Fixes oopses observed with the drm/asahi driver, found with kASAN.

Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230406-scheduler-uaf-2-v1-1-972531cf0a81@asahilina.net
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>

drm/scheduler: Fix lockup in drm_sched_entity_kill()

The drm_sched_entity_kill() is invoked twice by drm_sched_entity_destroy()
while userspace process is exiting or being killed. First time it's invoked
when sched entity is flushed and second time when entity is released. This
causes a lockup within wait_for_completion(entity_idle) due to how completion
API works.

Calling wait_for_completion() more times than complete() was invoked is a
error condition that causes lockup because completion internally uses
counter for complete/wait calls. The complete_all() must be used instead
in such cases.

This patch fixes lockup of Panfrost driver that is reproducible by killing
any application in a middle of 3d drawing operation.

Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221123001303.533968-1-dmitry.osipenko@collabora.com

drm/scheduler: Fix lockup in drm_sched_entity_kill()

The drm_sched_entity_kill() is invoked twice by drm_sched_entity_destroy()
while userspace process is exiting or being killed. First time it's invoked
when sched entity is flushed and second time when entity is released. This
causes a lockup within wait_for_completion(entity_idle) due to how completion
API works.

Calling wait_for_completion() more times than complete() was invoked is a
error condition that causes lockup because completion internally uses
counter for complete/wait calls. The complete_all() must be used instead
in such cases.

This patch fixes lockup of Panfrost driver that is reproducible by killing
any application in a middle of 3d drawing operation.

Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://patchwork.freedesktop.org/patch/msgid/20221123001303.533968-1-dmitry.osipenko@collabora.com

drm/scheduler: Fix lockup in drm_sched_entity_kill()

The drm_sched_entity_kill() is invoked twice by drm_sched_entity_destroy()
while userspace process is exiting or being killed. First time it's invoked
when sched entity is flushed and second time when entity is released. This
causes a lockup within wait_for_completion(entity_idle) due to how completion
API works.

Calling wait_for_completion() more times than complete() was invoked is a
error condition that causes lockup because completion internally uses
counter for complete/wait calls. The complete_all() must be used instead
in such cases.

This patch fixes lockup of Panfrost driver that is reproducible by killing
any application in a middle of 3d drawing operation.

Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://patchwork.freedesktop.org/patch/msgid/20221123001303.533968-1-dmitry.osipenko@collabora.com

drm/scheduler: rename dependency callback into prepare_job

This now matches much better what this is doing.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014084641.128280-14-christian.koenig@amd.com

drm/scheduler: rework entity flush, kill and fini

This was buggy because when we had to wait for entities which were
killed as well we would just deadlock.

Instead move all the dependency handling into the callbacks so that
will all happen asynchronously.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014084641.128280-13-christian.koenig@amd.com

drm/scheduler: fix fence ref counting

We leaked dependency fences when processes were beeing killed.

Additional to that grab a reference to the last scheduled fence.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220929180151.139751-1-christian.koenig@amd.com

drm/sched: Add FIFO sched policy to run queue

When many entities are competing for the same run queue
on the same scheduler, we observe an unusually long wait
times and some jobs get starved. This has been observed on GPUVis.

The issue is due to the Round Robin policy used by schedulers
to pick up the next entity's job queue for execution. Under stress
of many entities and long job queues within entity some
jobs could be stuck for very long time in it's entity's
queue before being popped from the queue and executed
while for other entities with smaller job queues a job
might execute earlier even though that job arrived later
then the job in the long queue.

Fix:
Add FIFO selection policy to entities in run queue, chose next entity
on run queue in such order that if job on one entity arrived
earlier then job on another entity the first job will start
executing earlier regardless of the length of the entity's job
queue.

v2:
Switch to rb tree structure for entities based on TS of
oldest job waiting in the job queue of an entity. Improves next
entity extraction to O(1). Entity TS update
O(log N) where N is the number of entities in the run-queue

Drop default option in module control parameter.

v3:
Various cosmetical fixes and minor refactoring of fifo update function. (Luben)

v4:
Switch drm_sched_rq_select_entity_fifo to in order search (Luben)

v5: Fix up drm_sched_rq_select_entity_fifo loop (Luben)

v6: Add missing drm_sched_rq_remove_fifo_locked

v7: Fix ts sampling bug and more cosmetic stuff (Luben)

v8: Fix module parameter string (Luben)

Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Direct Rendering Infrastructure - Development <dri-devel@lists.freedesktop.org>
Cc: AMD Graphics <amd-gfx@lists.freedesktop.org>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Tested-by: Yunxiang Li (Teddy) <Yunxiang.Li@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220930041258.1050247-1-luben.tuikov@amd.com

drm/scheduler: fix fence ref counting

We leaked dependency fences when processes were beeing killed.

Additional to that grab a reference to the last scheduled fence.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220929180151.139751-1-christian.koenig@amd.com

drm/sched: add DRM_SCHED_FENCE_DONT_PIPELINE flag

Setting this flag on a scheduler fence prevents pipelining of jobs
depending on this fence. In other words we always insert a full CPU
round trip before dependent jobs are pushed to the pipeline.

Signed-off-by: Christian König <christian.koenig@amd.com>
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2113#note_1579296
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014081553.114899-1-christian.koenig@amd.com

drm/scheduler: Don't kill jobs in interrupt context

Interrupt context can't sleep. Drivers like Panfrost and MSM are taking
mutex when job is released, and thus, that code can sleep. This results
into "BUG: scheduling while atomic" if locks are contented while job is
freed. There is no good reason for releasing scheduler's jobs in IRQ
context, hence use normal context to fix the trouble.

Cc: stable@vger.kernel.org
Fixes: 542cff7893a3 ("drm/sched: Avoid lockdep spalt on killing a processes")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220411221536.283312-1-dmitry.osipenko@collabora.com

drm/scheduler: Don't kill jobs in interrupt context

Interrupt context can't sleep. Drivers like Panfrost and MSM are taking
mutex when job is released, and thus, that code can sleep. This results
into "BUG: scheduling while atomic" if locks are contented while job is
freed. There is no good reason for releasing scheduler's jobs in IRQ
context, hence use normal context to fix the trouble.

Cc: stable@vger.kernel.org
Fixes: 542cff7893a3 ("drm/sched: Avoid lockdep spalt on killing a processes")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220411221536.283312-1-dmitry.osipenko@collabora.com

drm/sched: Avoid lockdep spalt on killing a processes

Probelm:
Singlaning one sched fence from within another's sched
fence singal callback generates lockdep splat because
the both have same lockdep class of their fence->lock

Fix:
Fix bellow stack by rescheduling to irq work of
signaling and killing of jobs that left when entity is killed.

[11176.741181] dump_stack+0x10/0x12
[11176.741186] __lock_acquire.cold+0x208/0x2df
[11176.741197] lock_acquire+0xc6/0x2d0
[11176.741204] ? dma_fence_signal+0x28/0x80
[11176.741212] _raw_spin_lock_irqsave+0x4d/0x70
[11176.741219] ? dma_fence_signal+0x28/0x80
[11176.741225] dma_fence_signal+0x28/0x80
[11176.741230] drm_sched_fence_finished+0x12/0x20 [gpu_sched]
[11176.741240] drm_sched_entity_kill_jobs_cb+0x1c/0x50 [gpu_sched]
[11176.741248] dma_fence_signal_timestamp_locked+0xac/0x1a0
[11176.741254] dma_fence_signal+0x3b/0x80
[11176.741260] drm_sched_fence_finished+0x12/0x20 [gpu_sched]
[11176.741268] drm_sched_job_done.isra.0+0x7f/0x1a0 [gpu_sched]
[11176.741277] drm_sched_job_done_cb+0x12/0x20 [gpu_sched]
[11176.741284] dma_fence_signal_timestamp_locked+0xac/0x1a0
[11176.741290] dma_fence_signal+0x3b/0x80
[11176.741296] amdgpu_fence_process+0xd1/0x140 [amdgpu]
[11176.741504] sdma_v4_0_process_trap_irq+0x8c/0xb0 [amdgpu]
[11176.741731] amdgpu_irq_dispatch+0xce/0x250 [amdgpu]
[11176.741954] amdgpu_ih_process+0x81/0x100 [amdgpu]
[11176.742174] amdgpu_irq_handler+0x26/0xa0 [amdgpu]
[11176.742393] __handle_irq_event_percpu+0x4f/0x2c0
[11176.742402] handle_irq_event_percpu+0x33/0x80
[11176.742408] handle_irq_event+0x39/0x60
[11176.742414] handle_edge_irq+0x93/0x1d0
[11176.742419] __common_interrupt+0x50/0xe0
[11176.742426] common_interrupt+0x80/0x90

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Suggested-by: Christian König <christian.koenig@amd.com>
Tested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://www.spinics.net/lists/dri-devel/msg321250.html

drm/sched: improve docs around drm_sched_entity

I found a few too many things that are tricky and not documented, so I
started typing.

I found a few more things that looked broken while typing, see the
varios FIXME in drm_sched_entity.

Also some of the usual logics:
- actually include sched_entity.c declarations, that was lost in the
move here: 620e762f9a98 ("drm/scheduler: move entity handling into
separate file")

- Ditch the kerneldoc for internal functions, keep the comments where
they're describing more than what the function name already implies.

- Switch drm_sched_entity to inline docs.

Acked-by: Melissa Wen <mwen@igalia.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Emma Anholt <emma@anholt.net>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210805104705.862416-7-daniel.vetter@ffwll.ch

drm/sched: drop entity parameter from drm_sched_push_job

Originally a job was only bound to the queue when we pushed this, but
now that's done in drm_sched_job_init, making that parameter entirely
redundant.

Remove it.

The same applies to the context parameter in
lima_sched_context_queue_task, simplify that too.

v2:
Rebase on top of msm adopting drm/sched

Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Emma Anholt <emma@anholt.net>
Acked-by: Melissa Wen <mwen@igalia.com>
Reviewed-by: Steven Price <steven.price@arm.com> (v1)
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Qiang Yu <yuq825@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: Emma Anholt <emma@anholt.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Nirmoy Das <nirmoy.das@amd.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Chen Li <chenli@uniontech.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Deepak R Varma <mh12gx2825@gmail.com>
Cc: Kevin Wang <kevin1.wang@amd.com>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: "Marek Olšák" <marek.olsak@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: Dennis Li <Dennis.Li@amd.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: etnaviv@lists.freedesktop.org
Cc: lima@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Melissa Wen <mwen@igalia.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210805104705.862416-6-daniel.vetter@ffwll.ch

drm/sched: Add dependency tracking

Instead of just a callback we can just glue in the gem helpers that
panfrost, v3d and lima currently use. There's really not that many
ways to skin this cat.

v2/3: Rebased.

v4: Repaint this shed. The functions are now called _add_dependency()
and _add_implicit_dependency()

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> (v3)
Reviewed-by: Steven Price <steven.price@arm.com> (v1)
Acked-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Nirmoy Das <nirmoy.aiemd@gmail.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210805104705.862416-5-daniel.vetter@ffwll.ch

drm/sched: Barriers are needed for entity->last_scheduled

It might be good enough on x86 with just READ_ONCE, but the write side
should then at least be WRITE_ONCE because x86 has total store order.

It's definitely not enough on arm.

Fix this proplery, which means
- explain the need for the barrier in both places
- point at the other side in each comment

Also pull out the !sched_list case as the first check, so that the
code flow is clearer.

While at it sprinkle some comments around because it was very
non-obvious to me what's actually going on here and why.

Note that we really need full barriers here, at first I thought
store-release and load-acquire on ->last_scheduled would be enough,
but we actually requiring ordering between that and the queue state.

v2: Put smp_rmp() in the right place and fix up comment (Andrey)

Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210805104705.862416-4-daniel.vetter@ffwll.ch

drm/sched: Split drm_sched_job_init

This is a very confusingly named function, because not just does it
init an object, it arms it and provides a point of no return for
pushing a job into the scheduler. It would be nice if that's a bit
clearer in the interface.

But the real reason is that I want to push the dependency tracking
helpers into the scheduler code, and that means drm_sched_job_init
must be called a lot earlier, without arming the job.

v2:
- don't change .gitignore (Steven)
- don't forget v3d (Emma)

v3: Emma noticed that I leak the memory allocated in
drm_sched_job_init if we bail out before the point of no return in
subsequent driver patches. To be able to fix this change
drm_sched_job_cleanup() so it can handle being called both before and
after drm_sched_job_arm().

Also improve the kerneldoc for this.

v4:
- Fix the drm_sched_job_cleanup logic, I inverted the booleans, as
usual (Melissa)

- Christian pointed out that drm_sched_entity_select_rq() also needs
to be moved into drm_sched_job_arm, which made me realize that the
job->id definitely needs to be moved too.

Shuffle things to fit between job_init and job_arm.

v5:
Reshuffle the split between init/arm once more, amdgpu abuses
drm_sched.ready to signal gpu reset failures. Also document this
somewhat. (Christian)

v6:
Rebase on top of the msm drm/sched support. Note that the
drm_sched_job_init() call is completely misplaced, and hence also the
split-out drm_sched_entity_push_job(). I've put in a FIXME which the next
patch will address.

v7: Drop the FIXME in msm, after discussions with Rob I agree it shouldn't
be a problem where it is now.

Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Melissa Wen <mwen@igalia.com>
Cc: Melissa Wen <melissa.srw@gmail.com>
Acked-by: Emma Anholt <emma@anholt.net>
Acked-by: Steven Price <steven.price@arm.com> (v2)
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> (v5)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Qiang Yu <yuq825@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Nirmoy Das <nirmoy.das@amd.com>
Cc: Deepak R Varma <mh12gx2825@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Kevin Wang <kevin1.wang@amd.com>
Cc: Chen Li <chenli@uniontech.com>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: "Marek Olšák" <marek.olsak@amd.com>
Cc: Dennis Li <Dennis.Li@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: Sonny Jiang <sonny.jiang@amd.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Tian Tao <tiantao6@hisilicon.com>
Cc: etnaviv@lists.freedesktop.org
Cc: lima@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: Emma Anholt <emma@anholt.net>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210817084917.3555822-1-daniel.vetter@ffwll.ch

drm/sched: Avoid data corruptions

Wait for all dependencies of a job to complete before
killing it to avoid data corruptions.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210519141407.88444-1-andrey.grodzovsky@amd.com

drm/scheduler: Fix hang when sched_entity released

Problem: If scheduler is already stopped by the time sched_entity
is released and entity's job_queue not empty I encountred
a hang in drm_sched_entity_flush. This is because drm_sched_entity_is_idle
never becomes false.

Fix: In drm_sched_fini detach all sched_entities from the
scheduler's run queues. This will satisfy drm_sched_entity_is_idle.
Also wakeup all those processes stuck in sched_entity flushing
as the scheduler main thread which wakes them up is stopped by now.

v2:
Reverse order of drm_sched_rq_remove_entity and marking
s_entity as stopped to prevent reinserion back to rq due
to race.

v3:
Drop drm_sched_rq_remove_entity, only modify entity->stopped
and check for it in drm_sched_entity_is_idle

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210512142648.666476-14-andrey.grodzovsky@amd.com

drm/scheduler/sched_entity: Fix some function name disparity

Fixes the following W=1 kernel build warning(s):

drivers/gpu/drm/scheduler/sched_entity.c:204: warning: expecting prototype for drm_sched_entity_kill_jobs(). Prototype was for drm_sched_entity_kill_jobs_cb() instead
drivers/gpu/drm/scheduler/sched_entity.c:262: warning: expecting prototype for drm_sched_entity_cleanup(). Prototype was for drm_sched_entity_fini() instead
drivers/gpu/drm/scheduler/sched_entity.c:305: warning: expecting prototype for drm_sched_entity_fini(). Prototype was for drm_sched_entity_destroy() instead

Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210416143725.2769053-25-lee.jones@linaro.org
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>

drm/sched: select new rq even if there is only one v3

This is necessary when changing priorities of an entity.

v2: test the sched_list instead of num_sched.
v3: set the sched_list to NULL when there is only one entry

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Sonny Jiang <sonny.jiang@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210305125155.2312-1-christian.koenig@amd.com

drm/scheduler: provide scheduler score externally

Allow multiple schedulers to share the load balancing score.

This is useful when one engine has different hw rings.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-and-Tested-by: Leo Liu <leo.liu@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210204144405.2737-1-christian.koenig@amd.com

gpu: drm: scheduler: sched_entity: Demote non-conformant kernel-doc headers

Fixes the following W=1 kernel build warning(s):

drivers/gpu/drm/scheduler/sched_entity.c:316: warning: Function parameter or member 'f' not described in 'drm_sched_entity_clear_dep'
drivers/gpu/drm/scheduler/sched_entity.c:316: warning: Function parameter or member 'cb' not described in 'drm_sched_entity_clear_dep'
drivers/gpu/drm/scheduler/sched_entity.c:330: warning: Function parameter or member 'f' not described in 'drm_sched_entity_wakeup'
drivers/gpu/drm/scheduler/sched_entity.c:330: warning: Function parameter or member 'cb' not described in 'drm_sched_entity_wakeup'

Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Nirmoy Das <nirmoy.aiemd@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/sched: Avoid infinite waits in the drm_sched_entity_destroy() path

If we don't initialize the entity to idle and the entity is never
scheduled before being destroyed we end up with an infinite wait in the
destroy path.

v2:
- Add Steven's R-b

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/393486/

drm/scheduler: improve job distribution with multiple queues

This patch uses score to select a new drm scheduler for better
loadbalance between multiple drm schedulers instead of num_jobs.

Below are test results after running amdgpu_test for ~10 times.

Before this patch:

sched_name num of many times it got schedule
========= ==================================
sdma0 1463
sdma1 198
comp_1.0.1 280

After this patch:

sched_name num of many times it got schedule
========= ==================================
sdma0 925
sdma1 928
comp_1.0.1 177
comp_1.1.1 44
comp_1.2.1 43
comp_1.3.1 44

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/373000/
Signed-off-by: Christian König <christian.koenig@amd.com>

drm/sched: implement and export drm_sched_pick_best

Remove drm_sched_entity_get_free_sched() and use the logic of picking
the least loaded drm scheduler from a drm scheduler list to implement
drm_sched_pick_best(). This patch also exports drm_sched_pick_best() so
that it can be utilized by other drm drivers.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Revert "drm/scheduler: improve job distribution with multiple queues"

It needs to revert this patch to avoid amdgpu_test compute hang problem
on picasso.

This reverts commit 56822db194232c089601728d68ed078dccb97f8b.

Signed-off-by: changzhu <Changfeng.Zhu@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: implement a function to modify sched list

Implement drm_sched_entity_modify_sched() which modifies existing
sched_list with a different one. This is going to be helpful when
userspace changes priority of a ctx/entity then the driver can switch
to the corresponding HW scheduler list for that priority.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amdgpu: fix doc by clarifying sched_list definition

expand sched_list definition for better understanding.
Also fix a typo atleast -> at least

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: fix documentation by replacing rq_list with sched_list

This also replaces old artifacts with a correct one in drm_sched_entity_init()
declaration

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: improve job distribution with multiple queues

This patch uses score based logic to select a new rq for better
loadbalance between multiple rq/scheds instead of num_jobs.

Below are test results after running amdgpu_test from mesa drm

Before this patch:

sched_name num of many times it got scheduled
========= ==================================
sdma0 314
sdma1 32
comp_1.0.0 56
comp_1.0.1 0
comp_1.1.0 0
comp_1.1.1 0
comp_1.2.0 0
comp_1.2.1 0
comp_1.3.0 0
comp_1.3.1 0
After this patch:

sched_name num of many times it got scheduled
========= ==================================
sdma0 216
sdma1 185
comp_1.0.0 39
comp_1.0.1 9
comp_1.1.0 12
comp_1.1.1 0
comp_1.2.0 12
comp_1.2.1 0
comp_1.3.0 12
comp_1.3.1 0

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: do not keep a copy of sched list

entity should not keep copy and maintain sched list for
itself.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: rework entity creation

Entity currently keeps a copy of run_queue list and modify it in
drm_sched_entity_set_priority(). Entities shouldn't modify run_queue
list. Use drm_gpu_scheduler list instead of drm_sched_rq list
in drm_sched_entity struct. In this way we can select a runqueue based
on entity/ctx's priority for a drm scheduler.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/sched: Use completion to wait for sched->thread idle v2.

Removes thread park/unpark hack from drm_sched_entity_fini and
by this fixes reactivation of scheduler thread while the thread
is supposed to be stopped.

v2: Per sched entity completion.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: use job count instead of peek

The spsc_queue_peek function is accessing queue->head which belongs to
the consumer thread and shouldn't be accessed by the producer

This is fixing a rare race condition when destroying entities.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Monk.liu@amd.com
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: use job count instead of peek

The spsc_queue_peek function is accessing queue->head which belongs to
the consumer thread and shouldn't be accessed by the producer

This is fixing a rare race condition when destroying entities.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Monk.liu@amd.com
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: drop use of drmP.h

Drop use of the deprecated drmP.h header file.
Fix fallout.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Cc: Sharat Masetty <smasetty@codeaurora.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190630061922.7254-26-sam@ravnborg.org

drm/sched: Fix entities with 0 rqs.

Some blocks in amdgpu can have 0 rqs.

Job creation already fails with -ENOENT when entity->rq is NULL,
so jobs cannot be pushed. Without a rq there is no scheduler to
pop jobs, and rq selection already does the right thing with a
list of length 0.

So the operations we need to fix are:
- Creation, do not set rq to rq_list[0] if the list can have length 0.
- Do not flush any jobs when there is no rq.
- On entity destruction handle the rq = NULL case.
- on set_priority, do not try to change the rq if it is NULL.

Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/sched: Always trace the dependencies we wait on, to fix a race.

The entity->dependency can go away completely once we've called
drm_sched_entity_add_dependency_cb() (if the cb is called before we
get around to tracing). The tracepoint is more useful if we trace
every dependency instead of just ones that get callbacks installed,
anyway, so just do that.

Fixes any easy-to-produce OOPS when tracing the scheduler on V3D with
"perf record -a -e gpu_scheduler:.\* glxgears" and DEBUG_SLAB enabled.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: Add drm_sched_job_cleanup

This patch adds a new API to clean up the scheduler job resources. This
is primarliy needed in cases the job was created but was not queued to
the scheduler queue. Additionally with this change, the layer which
creates the scheduler job also gets to free up the job's resources and
this entails moving the dma_fence_put(finished_fence) to the drivers
ops free handler routines.

Signed-off-by: Sharat Masetty <smasetty@codeaurora.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/sched: Add boolean to mark if sched is ready to work v5

Problem:
A particular scheduler may become unsuable (underlying HW) after
some event (e.g. GPU reset). If it's later chosen by
the get free sched. policy a command will fail to be
submitted.

Fix:
Add a driver specific callback to report the sched status so
rq with bad sched can be avoided in favor of working one or
none in which case job init will fail.

v2: Switch from driver callback to flag in scheduler.

v3: rebase

v4: Remove ready paramter from drm_sched_init, set
uncoditionally to true once init done.

v5: fix missed change in v3d in v4 (Alex)

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: Simplify spsc_queue_count check in drm_sched_entity_select_rq

Clang generates a warning when it sees a logical not followed by a
conditional operator like ==, >, or <.

drivers/gpu/drm/scheduler/sched_entity.c:470:6: warning: logical not is
only applied to the left hand side of this comparison
[-Wlogical-not-parentheses]
if (!spsc_queue_count(&entity->job_queue) == 0 ||
^ ~~
drivers/gpu/drm/scheduler/sched_entity.c:470:6: note: add parentheses
after the '!' to evaluate the comparison first
if (!spsc_queue_count(&entity->job_queue) == 0 ||
^
( )
drivers/gpu/drm/scheduler/sched_entity.c:470:6: note: add parentheses
around left hand side expression to silence this warning
if (!spsc_queue_count(&entity->job_queue) == 0 ||
^
( )
1 warning generated.

It assumes the author might have made a mistake in their logic:

if (!a == b) -> if (!(a == b))

Sometimes that is the case; other times, it's just a super convoluted
way of saying 'if (a)' when b = 0:

if (!1 == 0) -> if (0 == 0) -> if (true)

Alternatively:

if (!1 == 0) -> if (!!1) -> if (1)

Simplify this comparison so that Clang doesn't complain.

Fixes: 35e160e781a0 ("drm/scheduler: change entities rq even earlier")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: avoid redundant shifting of the entity v2

do not remove entity from the rq if the current rq is from
the least loaded scheduler.

Signed-off-by: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: Add stopped flag to drm_sched_entity

The flag will prevent another thread from same process to
reinsert the entity queue into scheduler's rq after it was already
removewd from there by another thread during drm_sched_entity_flush.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: cleanup entity coding style

Cleanup coding style in sched_entity.c

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/scheduler: move entity handling into separate file

This is complex enough on it's own. Move it into a separate C file.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>