drm/amdgpu/userq: serialize queue map against GPU reset

Creating a user queue can race with a GPU reset. While recovery holds
reset_domain->sem for write, MES is unresponsive, so the ADD_QUEUE from
amdgpu_userq_map_helper() times out (-110) and an otherwise valid queue
create fails:

  amdgpu: MES(0) failed to respond to msg=ADD_QUEUE
  [drm:mes_userq_map [amdgpu]] *ERROR* Failed to map queue in HW, err (-110)
  amdgpu: [drm] *ERROR* ... Failed to map Queue
  amdgpu: [drm] *ERROR* ... Failed to create usermode queue

Take reset_domain->sem for read around the map so it runs only once MES
is back up. This mirrors amdgpu_userq_cleanup() and honors the
userq_mutex -> reset_domain->sem order; the reset path never takes
userq_mutex, so there is no deadlock.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit a8e151fe629c63b0eb08aa57de0d434614db3e1b)
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
index 3efe1ae273861eba8f28a24e4ac969126f4a7f37..b18d78720656252e50dd829f65939b7be1a25007 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
@@ -700,7 +700,12 @@ amdgpu_userq_create(struct drm_file *filp, union drm_amdgpu_userq *args)
        if (!adev->userq_halt_for_enforce_isolation ||
            ((queue->queue_type != AMDGPU_HW_IP_GFX) &&
             (queue->queue_type != AMDGPU_HW_IP_COMPUTE))) {
+               /* Serialize the map against an in-progress GPU reset (MES is
+                * unresponsive during recovery), matching amdgpu_userq_cleanup().
+                */
+               down_read(&adev->reset_domain->sem);
                r = amdgpu_userq_map_helper(queue);
+               up_read(&adev->reset_domain->sem);
                if (r) {
                        drm_file_err(uq_mgr->file, "Failed to map Queue\n");
                        mutex_unlock(&uq_mgr->userq_mutex);