From: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Date: Tue, 10 Oct 2017 16:50:17 -0400
Subject: drm/amdgpu: Move old fence waiting before reservation lock is aquired
 v2
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Git-commit: 0ae94444c08a0adf2fab4aab26be0646ee445a19
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Helps avoiding deadlock during GPU reset.
Added mutex to amdgpu_ctx to preserve order of fences on a ring.

v2:
Put waiting logic in a function in a seperate function in amdgpu_ctx.c

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h     |    4 ++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c  |   10 ++++++----
 drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c |   30 ++++++++++++++++++++++++------
 3 files changed, 34 insertions(+), 10 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -738,6 +738,7 @@ struct amdgpu_ctx {
 	bool 			preamble_presented;
 	enum amd_sched_priority init_priority;
 	enum amd_sched_priority override_priority;
+	struct mutex            lock;
 };
 
 struct amdgpu_ctx_mgr {
@@ -760,9 +761,12 @@ void amdgpu_ctx_priority_override(struct
 int amdgpu_ctx_ioctl(struct drm_device *dev, void *data,
 		     struct drm_file *filp);
 
+int amdgpu_ctx_wait_prev_fence(struct amdgpu_ctx *ctx, unsigned ring_id);
+
 void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr *mgr);
 void amdgpu_ctx_mgr_fini(struct amdgpu_ctx_mgr *mgr);
 
+
 /*
  * file private structure
  */
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -90,6 +90,8 @@ static int amdgpu_cs_parser_init(struct
 		goto free_chunk;
 	}
 
+	mutex_lock(&p->ctx->lock);
+
 	/* get chunks */
 	chunk_array_user = u64_to_user_ptr(cs->in.chunks);
 	if (copy_from_user(chunk_array, chunk_array_user,
@@ -735,8 +737,10 @@ static void amdgpu_cs_parser_fini(struct
 
 	dma_fence_put(parser->fence);
 
-	if (parser->ctx)
+	if (parser->ctx) {
+		mutex_unlock(&parser->ctx->lock);
 		amdgpu_ctx_put(parser->ctx);
+	}
 	if (parser->bo_list)
 		amdgpu_bo_list_put(parser->bo_list);
 
@@ -893,9 +897,7 @@ static int amdgpu_cs_ib_vm_chunk(struct
 			r = amdgpu_ring_parse_cs(ring, p, j);
 			if (r)
 				return r;
-
 		}
-
 		j++;
 	}
 
@@ -983,7 +985,7 @@ static int amdgpu_cs_ib_fill(struct amdg
 	    parser->job->ring->funcs->type == AMDGPU_RING_TYPE_VCE))
 		return -EINVAL;
 
-	return 0;
+	return amdgpu_ctx_wait_prev_fence(parser->ctx, parser->job->ring->idx);
 }
 
 static int amdgpu_cs_process_fence_dep(struct amdgpu_cs_parser *p,
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -67,6 +67,8 @@ static int amdgpu_ctx_init(struct amdgpu
 	if (!ctx->fences)
 		return -ENOMEM;
 
+	mutex_init(&ctx->lock);
+
 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 		ctx->rings[i].sequence = 1;
 		ctx->rings[i].fences = &ctx->fences[amdgpu_sched_jobs * i];
@@ -126,6 +128,8 @@ static void amdgpu_ctx_fini(struct amdgp
 				      &ctx->rings[i].entity);
 
 	amdgpu_queue_mgr_fini(adev, &ctx->queue_mgr);
+
+	mutex_destroy(&ctx->lock);
 }
 
 static int amdgpu_ctx_alloc(struct amdgpu_device *adev,
@@ -296,12 +300,8 @@ int amdgpu_ctx_add_fence(struct amdgpu_c
 
 	idx = seq & (amdgpu_sched_jobs - 1);
 	other = cring->fences[idx];
-	if (other) {
-		signed long r;
-		r = dma_fence_wait_timeout(other, true, MAX_SCHEDULE_TIMEOUT);
-		if (r < 0)
-			return r;
-	}
+	if (other)
+		BUG_ON(!dma_fence_is_signaled(other));
 
 	dma_fence_get(fence);
 
@@ -372,6 +372,24 @@ void amdgpu_ctx_priority_override(struct
 	}
 }
 
+int amdgpu_ctx_wait_prev_fence(struct amdgpu_ctx *ctx, unsigned ring_id)
+{
+	struct amdgpu_ctx_ring *cring = &ctx->rings[ring_id];
+	unsigned idx = cring->sequence & (amdgpu_sched_jobs - 1);
+	struct dma_fence *other = cring->fences[idx];
+
+	if (other) {
+		signed long r;
+		r = dma_fence_wait_timeout(other, false, MAX_SCHEDULE_TIMEOUT);
+		if (r < 0) {
+			DRM_ERROR("Error (%ld) waiting for fence!\n", r);
+			return r;
+		}
+	}
+
+	return 0;
+}
+
 void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr *mgr)
 {
 	mutex_init(&mgr->lock);