drm: Create a task info option for wedge events

This patchset implements a request made by Xaver Hugl about wedge events:

"I'd really like to have the PID of the client that triggered the GPU
reset, so that we can kill it if multiple resets are triggered in a
row (or switch to software rendering if it's KWin itself) and show a
user-friendly notification about why their app(s) crashed, but that
can be added later."

From https://lore.kernel.org/dri-devel/CAFZQkGwJ4qgHV8WTp2=svJ...

For testing, I've used amdgpu's debug_mask options debug_disable_soft_recovery
and debug_disable_gpu_ring_reset to test both wedge event paths in the driver.
To trigger a ring timeout, I've used this app:
https://gitlab.freedesktop.org/andrealmeid/gpu-timeout

Thanks!

Changelog:

v8:
 - New patch "Allow NULL pointers at amdgpu_vm_put_task_info()"
 - Dropped inline for amdgpu_vm_print_task_info()
 - Code style changes for "Create a task info option for wedge events"
 - Drop check before calling amdgpu_vm_put_task_info()

v7:
 - Change `char *comm` to `char comm[TASK_COMM_LEN]`
 - New patches to encapsulate struct drm_wedge_task_info inside of struct
   amdgpu_task_info
 - Remove struct cast for struct amdgpu_task_info, now we can use `info =
   &ti->task`
 - Fix struct lifetime, move amdgpu_vm_put_task_info() after
   drm_dev_wedged_event() call

v6:
 - Check if PID >= 0 for displaying the task info
 - s/app/task in a comment

v5:
 - Change from app to task also in structs, commit message and docs
 - Add a check for NULL or empty task name string

v4:
 - Change from APP to TASK
 - Add defines for event_string and pid_string length

v3:
 - Make comm_string and pid_string empty when there's no app info
 - Change "app that caused ..." to "app involved ..."
 - Clarify that devcoredump have more information about what happened

v2:
  - Rebased on top of drm/drm-next
  - Added new patch for documentation

André Almeida (6):
  drm: amdgpu: Allow NULL pointers at amdgpu_vm_put_task_info()
  drm: amdgpu: Create amdgpu_vm_print_task_info()
  drm: Create a task info option for wedge events
  drm/doc: Add a section about "Task information" for the wedge API
  drm: amdgpu: Use struct drm_wedge_task_info inside of struct
    amdgpu_task_info
  drm/amdgpu: Make use of drm_wedge_task_info

 Documentation/gpu/drm-uapi.rst                | 17 ++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c   |  2 +-
 .../gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c  |  4 ++--
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    | 13 +++++++++--
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_job.c       | 11 +++++-----
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        | 22 ++++++++++++++-----
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h        |  6 +++--
 drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c        |  5 +----
 drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c        |  5 +----
 drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c        |  5 +----
 drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c         |  4 +---
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c         |  5 +----
 drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c        |  2 +-
 drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c      |  2 +-
 drivers/gpu/drm/amd/amdkfd/kfd_events.c       |  2 +-
 drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c   |  8 +++----
 drivers/gpu/drm/drm_drv.c                     | 21 ++++++++++++++----
 drivers/gpu/drm/i915/gt/intel_reset.c         |  3 ++-
 drivers/gpu/drm/xe/xe_device.c                |  3 ++-
 include/drm/drm_device.h                      |  9 ++++++++
 include/drm/drm_drv.h                         |  3 ++-
 22 files changed, 103 insertions(+), 51 deletions(-)

-- 
2.49.0