[PATCH v2] drm: add tdr support for embeded hw_fence

[Jingwen Chen]

[Why]
After embeded hw_fence to amdgpu_job, we need to add tdr support
for this feature.

[How]
1. Add a resubmit_flag for resubmit jobs.
2. Clear job fence from RCU and force complete vm flush fences in
   pre_asic_reset
3. skip dma_fence_get for resubmit jobs and add a dma_fence_put
   for guilty jobs.

Signed-off-by: Jack Zhang <Jack.Zhang1 at amd.com>
Signed-off-by: Jingwen Chen <Jingwen.Chen2 at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 12 +++++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c  | 13 +++++++++----
 drivers/gpu/drm/amd/amdgpu/amdgpu_job.c    |  4 +++-
 drivers/gpu/drm/scheduler/sched_main.c     |  1 +
 include/drm/gpu_scheduler.h                |  1 +
 5 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 280b1940e892..df73fe666e87 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4382,7 +4382,7 @@ int amdgpu_device_mode1_reset(struct amdgpu_device *adev)
 int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
 				 struct amdgpu_reset_context *reset_context)
 {
-	int i, r = 0;
+	int i, j, r = 0;
 	struct amdgpu_job *job = NULL;
 	bool need_full_reset =
 		test_bit(AMDGPU_NEED_FULL_RESET, &reset_context->flags);
@@ -4406,6 +4406,16 @@ int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
 		if (!ring || !ring->sched.thread)
 			continue;
 
+		/*clear job fence from fence drv to avoid force_completion
+		 *leave NULL and vm flush fence in fence drv */
+		for (j = 0; j <= ring->fence_drv.num_fences_mask; j ++) {
+			struct dma_fence *old,**ptr;
+			ptr = &ring->fence_drv.fences[j];
+			old = rcu_dereference_protected(*ptr, 1);
+			if (old && test_bit(DMA_FENCE_FLAG_USER_BITS, &old->flags))) {
+				RCU_INIT_POINTER(*ptr, NULL);
+			}
+		}
 		/* after all hw jobs are reset, hw fence is meaningless, so force_completion */
 		amdgpu_fence_driver_force_completion(ring);
 	}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index eecf21d8ec33..d5b3d5f8f951 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -157,10 +157,15 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f, struct amd
 	}
 
 	seq = ++ring->fence_drv.sync_seq;
-	dma_fence_init(fence, &amdgpu_fence_ops,
-		       &ring->fence_drv.lock,
-		       adev->fence_context + ring->idx,
-		       seq);
+	if (job != NULL && job->base.resubmit_flag == 1) {
+		/* reset seq for resubmitted jobs */
+		fence->seqno = seq;
+	} else {
+		dma_fence_init(fence, &amdgpu_fence_ops,
+				&ring->fence_drv.lock,
+				adev->fence_context + ring->idx,
+				seq);
+	}
 
 	if (job != NULL) {
 		/* mark this fence has a parent job */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
index 7c426e225b24..d6f848adc3f4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
@@ -241,6 +241,7 @@ static struct dma_fence *amdgpu_job_run(struct drm_sched_job *sched_job)
 		dma_fence_set_error(finished, -ECANCELED);/* skip IB as well if VRAM lost */
 
 	if (finished->error < 0) {
+		dma_fence_put(&job->hw_fence);
 		DRM_INFO("Skip scheduling IBs!\n");
 	} else {
 		r = amdgpu_ib_schedule(ring, job->num_ibs, job->ibs, job,
@@ -249,7 +250,8 @@ static struct dma_fence *amdgpu_job_run(struct drm_sched_job *sched_job)
 			DRM_ERROR("Error scheduling IBs (%d)\n", r);
 	}
 
-	dma_fence_get(fence);
+	if (!job->base.resubmit_flag)
+		dma_fence_get(fence);
 	amdgpu_job_free_resources(job);
 
 	fence = r ? ERR_PTR(r) : fence;
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index f4f474944169..5a36ab5aea2d 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -544,6 +544,7 @@ void drm_sched_resubmit_jobs_ext(struct drm_gpu_scheduler *sched, int max)
 			dma_fence_set_error(&s_fence->finished, -ECANCELED);
 
 		dma_fence_put(s_job->s_fence->parent);
+		s_job->resubmit_flag = 1;
 		fence = sched->ops->run_job(s_job);
 		i++;
 
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index 4ea8606d91fe..06c101af1f71 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -198,6 +198,7 @@ struct drm_sched_job {
 	enum drm_sched_priority		s_priority;
 	struct drm_sched_entity         *entity;
 	struct dma_fence_cb		cb;
+	int resubmit_flag;
 };
 
 static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
-- 
2.25.1