[PATCH v2 0/3] drm/panthor: Report fault information to userspace

[Christian Gmeiner]

The Panthor CSF firmware and hardware report extra information when a
fault happens. Two kinds of faults matter here:
* faults raised at the address space level. These are fatal for every
  group bound to that VM.
* fatal faults raised on one of the queues of a group. They stop
  further submissions on that group.

This series exposes that information to userspace, so the
VK_KHR_device_fault extension can be implemented on top of it.

VM faults are reported through VM_GET_STATE. The VM keeps the raw
AS_FAULTSTATUS and AS_FAULTADDRESS of its last fault. Queue fatal
errors are reported through GROUP_GET_STATE. Each queue keeps its raw
CS_FATAL and CS_FATAL_INFO, and the ioctl returns them in an array
indexed by queue. The kernel does not decode the values, userspace
does. Nothing is allocated in the fault paths.

Changes in v2:
- Report VM faults through VM_GET_STATE instead of copying them into
  every group bound to the VM.
- Pass the raw register values to userspace instead of decoded fields.
- Keep one fatal slot per queue. A queue stops at its first fatal
  error, so no allocation is needed.
- Store the uAPI structs directly in the kernel objects.
- Dropped the recoverable CS_FAULT reporting for now.
- Bump the driver version to 1.10 in a separate patch.
- Rebased on drm-misc-next. The queue fatal info is protected by
  events_lock now that fatal events are processed under it.

Link to v1: https://lore.kernel.org/r/20251215115457.2137485-1-lukas.zapolskas@xxxxxxx

Signed-off-by: Christian Gmeiner <cgmeiner@xxxxxxxxxx>
---
Christian Gmeiner (3):
      drm/panthor: Report the last VM fault through VM_GET_STATE
      drm/panthor: Report the CS fatal errors through GROUP_GET_STATE
      drm/panthor: Bump the driver version to 1.10

 drivers/gpu/drm/panthor/panthor_drv.c   | 26 +++++++++++++++--
 drivers/gpu/drm/panthor/panthor_mmu.c   | 33 +++++++++++++++++++--
 drivers/gpu/drm/panthor/panthor_mmu.h   |  2 ++
 drivers/gpu/drm/panthor/panthor_sched.c | 32 +++++++++++++++++++-
 drivers/gpu/drm/panthor/panthor_sched.h |  5 +++-
 include/uapi/drm/panthor_drm.h          | 52 +++++++++++++++++++++++++++++++++
 6 files changed, 143 insertions(+), 7 deletions(-)
---
base-commit: 6f7098738fff3ec7393f924343188cb8e6ebc5d2
change-id: 20261014-panthor-fault-info-v2-330a9f771fd3

Best regards,
-- 
Christian Gmeiner <cgmeiner@xxxxxxxxxx>