linux.git/drivers/gpu/drm/msm/msm_gpu.c, branch v5.16

drm/msm: prevent NULL dereference in msm_gpu_crashstate_capture()

2021-10-15T20:26:33+00:00

Coverity complains of a possible NULL dereference:

CID 120718 (#1 of 1): Dereference null return value (NULL_RETURNS)
23. dereference: Dereferencing a pointer that might be NULL state->bos when
    calling msm_gpu_crashstate_get_bo. [show details]
301                        msm_gpu_crashstate_get_bo(state, submit->bos[i].obj,
302                                submit->bos[i].iova, submit->bos[i].flags);

Fix this by employing the same state->bos NULL check as is used in the next
for loop.

Cc: Rob Clark 
Cc: Sean Paul 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: linux-arm-msm@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: freedreno@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tim Gardner 
Reviewed-by: Dmitry Baryshkov 
Link: https://lore.kernel.org/r/20210929162554.14295-1-tim.gardner@canonical.com
Signed-off-by: Dmitry Baryshkov 
Signed-off-by: Rob Clark

drm/msm: Conversion to drm scheduler

2021-07-28T16:19:00+00:00

For existing adrenos, there is one or more ringbuffer, depending on
whether preemption is supported.  When preemption is supported, each
ringbuffer has it's own priority.  A submitqueue (which maps to a
gl context or vk queue in userspace) is mapped to a specific ring-
buffer at creation time, based on the submitqueue's priority.

Each ringbuffer has it's own drm_gpu_scheduler.  Each submitqueue
maps to a drm_sched_entity.  And each submit maps to a drm_sched_job.

Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/4
Signed-off-by: Rob Clark 
Acked-by: Christian König 
Link: https://lore.kernel.org/r/20210728010632.2633470-10-robdclark@gmail.com
Signed-off-by: Rob Clark

drm/msm: Consolidate submit bo state

2021-07-28T01:09:18+00:00

Move all the locked/active/pinned state handling to msm_gem_submit.c.
In particular, for drm/scheduler, we'll need to do all this before
pushing the submit job to the scheduler.  But while we're at it we can
get rid of the dupicate pin and refcnt.

Signed-off-by: Rob Clark 
Acked-by: Christian König 
Link: https://lore.kernel.org/r/20210728010632.2633470-7-robdclark@gmail.com
Signed-off-by: Rob Clark

drm/msm: drop drm_gem_object_put_locked()

2021-07-28T01:09:18+00:00

No idea why we were still using this.  It certainly hasn't been needed
for some time.  So drop the pointless twin codepaths.

Signed-off-by: Rob Clark 
Acked-by: Christian König 
Link: https://lore.kernel.org/r/20210728010632.2633470-4-robdclark@gmail.com
Signed-off-by: Rob Clark

drm/msm: Devfreq tuning

2021-07-28T00:54:36+00:00

This adds a few things to try and make frequency scaling better match
the workload:

1) Longer polling interval to avoid whip-lashing between too-high and
   too-low frequencies in certain workloads, like mobile games which
   throttle themselves to 30fps.

   Previously our polling interval was short enough to let things
   ramp down to minimum freq in the "off" frame, but long enough to
   not react quickly enough when rendering started on the next frame,
   leading to uneven frame times.  (Ie. rather than a consistent 33ms
   it would alternate between 16/33/48ms.)

2) Awareness of when the GPU is active vs idle.  Since we know when
   the GPU is active vs idle, we can clamp the frequency down to the
   minimum while it is idle.  (If it is idle for long enough, then
   the autosuspend delay will eventually kick in and power down the
   GPU.)

   Since devfreq has no knowledge of powered-but-idle, this takes a
   small bit of trickery to maintain a "fake" frequency while idle.
   This, combined with the longer polling period allows devfreq to
   arrive at a reasonable "active" frequency, while still clamping
   to minimum freq when idle to reduce power draw.

3) Boost.  Because simple_ondemand needs to see a certain threshold
   of busyness to ramp up, we could end up needing multiple polling
   cycles before it reacts appropriately on interactive workloads
   (ex. scrolling a web page after reading for some time), on top
   of the already lengthened polling interval, when we see a idle
   to active transition after a period of idle time we boost the
   frequency that we return to.

Signed-off-by: Rob Clark 
Link: https://lore.kernel.org/r/20210726144653.2180096-4-robdclark@gmail.com
Signed-off-by: Rob Clark

drm/msm: Split out devfreq handling

2021-07-28T00:54:36+00:00

Before we start adding more cleverness, split it into it's own file.

Signed-off-by: Rob Clark 
Reviewed-by: Dmitry Baryshkov 
Link: https://lore.kernel.org/r/20210726144653.2180096-2-robdclark@gmail.com
Signed-off-by: Rob Clark

drm/msm: Signal fences sooner

2021-07-28T00:53:52+00:00

Nothing we do to in update_fences() can't be done in an atomic context,
so move this into the GPU's irq context to reduce latency (and call
dma_fence_signal() so we aren't relying on dma_fence_is_signaled() which
would defeat the purpose).

Signed-off-by: Rob Clark 
Link: https://lore.kernel.org/r/20210726144359.2179302-3-robdclark@gmail.com
Signed-off-by: Rob Clark

drm/msm: devcoredump iommu fault support

2021-06-23T14:33:55+00:00

Wire up support to stall the SMMU on iova fault, and collect a devcore-
dump snapshot for easier debugging of faults.

Currently this is a6xx-only, but mostly only because so far it is the
only one using adreno-smmu-priv.

Signed-off-by: Rob Clark 
Acked-by: Jordan Crouse 
Link: https://lore.kernel.org/r/20210610214431.539029-6-robdclark@gmail.com
Signed-off-by: Rob Clark

drm/msm: export hangcheck_period in debugfs

2021-06-23T14:33:55+00:00

While keeping the previous default value for hangcheck period,
we allow now the possibility of configuring its value via
debugfs.

Signed-off-by: Samuel Iglesias Gonsalvez 
Link: https://lore.kernel.org/r/20210607104441.184700-1-siglesias@igalia.com
Signed-off-by: Rob Clark

drm/msm: Add param for userspace to query suspend count

2021-04-07T18:05:43+00:00

Performance counts, and ALWAYS_ON counters used for capturing GPU
timestamps, lose their state across suspend/resume cycles.  Userspace
tooling for performance monitoring needs to be aware of this.  For
example, after a suspend userspace needs to recalibrate it's offset
between CPU and GPU time.

Signed-off-by: Rob Clark 
Acked-by: Jordan Crouse 
Link: https://lore.kernel.org/r/20210325012358.1759770-3-robdclark@gmail.com
Signed-off-by: Rob Clark