drm/amdgpu: Handle the GPU recovery failure in SRIOV environment.

This patch handles the GPU recovery failure in sriov environment by
retrying the reset if the first reset fails. To determine the condition
of retry, a new macro AMDGPU_RETRY_SRIOV_RESET is added which returns
true if failure is due to ETIMEDOUT, EINVAL or EBUSY, otherwise return
false.A new macro AMDGPU_MAX_RETRY_LIMIT is used to limit the retry to 2.

It also handles the return status in Post Asic Reset by updating the return
code with asic_reset_res and eventually return the return code in
amdgpu_job_timedout().

Signed-off-by: Surbhi Kakarya <[e-mail]>
Reviewed-by: Andrey Grodzovsky <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

···
 MODULE_FIRMWARE("amdgpu/yellow_carp_gpu_info.bin");
 
 #define AMDGPU_RESUME_MS		2000
+#define AMDGPU_MAX_RETRY_LIMIT		2
+#define AMDGPU_RETRY_SRIOV_RESET(r) ((r) == -EBUSY || (r) == -ETIMEDOUT || (r) == -EINVAL)
 
 const char *amdgpu_asic_name[] = {
 	"TAHITI",
···
 {
 	int r;
 	struct amdgpu_hive_info *hive = NULL;
+	int retry_limit = 0;
 
+retry:
 	amdgpu_amdkfd_pre_reset(adev);
 
 	amdgpu_amdkfd_pre_reset(adev);
···
 		r = amdgpu_device_recover_vram(adev);
 	}
 	amdgpu_virt_release_full_gpu(adev, true);
+
+	if (AMDGPU_RETRY_SRIOV_RESET(r)) {
+		if (retry_limit < AMDGPU_MAX_RETRY_LIMIT) {
+			retry_limit++;
+			goto retry;
+		} else
+			DRM_ERROR("GPU reset retry is beyond the retry limit\n");
+	}
 
 	return r;
 }
···
 		if (!drm_drv_uses_atomic_modeset(adev_to_drm(tmp_adev)) && !job_signaled) {
 			drm_helper_resume_force_mode(adev_to_drm(tmp_adev));
 		}
+
+		if (tmp_adev->asic_reset_res)
+			r = tmp_adev->asic_reset_res;
 
 		tmp_adev->asic_reset_res = 0;
 

drivers/gpu/drm/amd/amdgpu/amdgpu_job.c

···
 	struct amdgpu_task_info ti;
 	struct amdgpu_device *adev = ring->adev;
 	int idx;
+	int r;
 
 	if (!drm_dev_enter(adev_to_drm(adev), &idx)) {
 		DRM_INFO("%s - device unplugged skipping recovery on scheduler:%s",
···
 		  ti.process_name, ti.tgid, ti.task_name, ti.pid);
 
 	if (amdgpu_device_should_recover_gpu(ring->adev)) {
-		amdgpu_device_gpu_recover(ring->adev, job);
+		r = amdgpu_device_gpu_recover(ring->adev, job);
+		if (r)
+			DRM_ERROR("GPU Recovery Failed: %d\n", r);
+
 	} else {
 		drm_sched_suspend_timeout(&ring->sched);
 		if (amdgpu_sriov_vf(adev))