[PATCH 08/16] drm/amdgpu: track ring state associated with a job

[Alex Deucher]

We need to know the wptr and sequence number associated
with a job so that we can re-emit the unprocessed state
after a ring reset.  Pre-allocate storage space for
the ring buffer contents and add a helper to save off
the unprocessed state so that it can be re-emitted
after the queue is reset.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c   |  6 ++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_job.c  |  5 ++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_job.h  |  2 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 23 +++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h |  5 +++++
 5 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
index 802743efa3b39..67df82d50a74a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
@@ -306,6 +306,12 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned int num_ibs,
 
 	amdgpu_ring_ib_end(ring);
 	amdgpu_ring_commit(ring);
+	/* This must be last for resets to work properly
+	 * as we need to save the wptr associated with this
+	 * job.
+	 */
+	if (job)
+		job->ring_wptr = ring->wptr;
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
index 0b9086a747c0a..c549e7c598459 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
@@ -91,6 +91,7 @@ static enum drm_gpu_sched_stat amdgpu_job_timedout(struct drm_sched_job *s_job)
 	struct amdgpu_job *job = to_amdgpu_job(s_job);
 	struct amdgpu_task_info *ti;
 	struct amdgpu_device *adev = ring->adev;
+	struct dma_fence *fence = &job->hw_fence;
 	int idx;
 	int r;
 
@@ -154,8 +155,10 @@ static enum drm_gpu_sched_stat amdgpu_job_timedout(struct drm_sched_job *s_job)
 		else
 			is_guilty = true;
 
-		if (is_guilty)
+		if (is_guilty) {
+			amdgpu_ring_backup_unprocessed_jobs(ring, job->ring_wptr, fence->seqno);
 			dma_fence_set_error(&s_job->s_fence->finished, -ETIME);
+		}
 
 		r = amdgpu_ring_reset(ring, job->vmid);
 		if (!r) {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
index f2c049129661f..c2ed0edb5179d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
@@ -79,6 +79,8 @@ struct amdgpu_job {
 	/* enforce isolation */
 	bool			enforce_isolation;
 	bool			run_cleaner_shader;
+	/* wptr for the job for resets */
+	uint32_t		ring_wptr;
 
 	uint32_t		num_ibs;
 	struct amdgpu_ib	ibs[];
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 426834806fbf2..f5833ac8026a8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -333,6 +333,12 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 	/*  Initialize cached_rptr to 0 */
 	ring->cached_rptr = 0;
 
+	if (!ring->ring_backup) {
+		ring->ring_backup = kvzalloc(ring->ring_size, GFP_KERNEL);
+		if (!ring->ring_backup)
+			return -ENOMEM;
+	}
+
 	/* Allocate ring buffer */
 	if (ring->ring_obj == NULL) {
 		r = amdgpu_bo_create_kernel(adev, ring->ring_size + ring->funcs->extra_dw, PAGE_SIZE,
@@ -342,6 +348,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 					    (void **)&ring->ring);
 		if (r) {
 			dev_err(adev->dev, "(%d) ring create failed\n", r);
+			kvfree(ring->ring_backup);
 			return r;
 		}
 		amdgpu_ring_clear_ring(ring);
@@ -385,6 +392,8 @@ void amdgpu_ring_fini(struct amdgpu_ring *ring)
 	amdgpu_bo_free_kernel(&ring->ring_obj,
 			      &ring->gpu_addr,
 			      (void **)&ring->ring);
+	kvfree(ring->ring_backup);
+	ring->ring_backup = NULL;
 
 	dma_fence_put(ring->vmid_wait);
 	ring->vmid_wait = NULL;
@@ -753,3 +762,17 @@ bool amdgpu_ring_sched_ready(struct amdgpu_ring *ring)
 
 	return true;
 }
+
+void amdgpu_ring_backup_unprocessed_jobs(struct amdgpu_ring *ring,
+					 u64 bad_wptr, u32 bad_seq)
+{
+	unsigned int entries_to_copy = ring->wptr - bad_wptr;
+	unsigned int idx, i;
+
+	for (i = 0; i < entries_to_copy; i++) {
+		idx = (bad_wptr + i) & ring->buf_mask;
+		ring->ring_backup[i] = ring->ring[idx];
+	}
+	ring->ring_backup_entries_to_copy = entries_to_copy;
+	ring->ring_backup_seq = bad_seq;
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index b95b471107692..a6e386a62b45d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -268,6 +268,9 @@ struct amdgpu_ring {
 
 	struct amdgpu_bo	*ring_obj;
 	uint32_t		*ring;
+	uint32_t		*ring_backup;
+	uint32_t		ring_backup_seq;
+	unsigned int		ring_backup_entries_to_copy;
 	unsigned		rptr_offs;
 	u64			rptr_gpu_addr;
 	volatile u32		*rptr_cpu_addr;
@@ -534,4 +537,6 @@ int amdgpu_ib_pool_init(struct amdgpu_device *adev);
 void amdgpu_ib_pool_fini(struct amdgpu_device *adev);
 int amdgpu_ib_ring_tests(struct amdgpu_device *adev);
 bool amdgpu_ring_sched_ready(struct amdgpu_ring *ring);
+void amdgpu_ring_backup_unprocessed_jobs(struct amdgpu_ring *ring,
+					 u64 bad_wptr, u32 bad_seq);
 #endif
-- 
2.49.0