[PATCHv2 2/2] drm/amd/amdgpu: 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.
v2:
use a job_run_counter in amdgpu_job to replace the resubmit_flag in
drm_sched_job. When the job_run_counter >= 1, it means this job is a
resubmit job.

Signed-off-by: Jack Zhang <Jack.Zhang7 at hotmail.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    |  5 ++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_job.h    |  3 +++
 4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 9e53ff851496..ade2fa07a50a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4447,7 +4447,7 @@ 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);
@@ -4471,6 +4471,16 @@ 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(AMDGPU_FENCE_FLAG_EMBED_IN_JOB_BIT, &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 5e29d797a265..c9752cf794fb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -159,10 +159,15 @@ 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->job_run_counter) {
+		/* reinit 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 65a395060de2..19b13a65c73b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
@@ -254,6 +254,7 @@ 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,
@@ -262,7 +263,9 @@ 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->job_run_counter)
+		dma_fence_get(fence);
+	job->job_run_counter ++;
 	amdgpu_job_free_resources(job);
 
 	fence = r ? ERR_PTR(r) : fence;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
index 92324c978534..1fa667f245e1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
@@ -64,6 +64,9 @@ struct amdgpu_job {
 	/* user fence handling */
 	uint64_t		uf_addr;
 	uint64_t		uf_sequence;
+
+	/* job_run_counter >= 1 means a resubmit job */
+	uint32_t		job_run_counter;
 };
 
 int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
-- 
2.25.1