dma-buf & drm/amdgpu: remove dma_resv workaround

Rework the internals of the dma_resv object to allow adding more than one
write fence and remember for each fence what purpose it had.

This allows removing the workaround from amdgpu which used a container for
this instead.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-4-christian.koenig@amd.com

1 files changed, 5 insertions, 48 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 76fd916424d6..8de283997769 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -574,14 +574,6 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 		struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
 
 		e->bo_va = amdgpu_vm_bo_find(vm, bo);
-
-		if (bo->tbo.base.dma_buf && !amdgpu_bo_explicit_sync(bo)) {
-			e->chain = dma_fence_chain_alloc();
-			if (!e->chain) {
-				r = -ENOMEM;
-				goto error_validate;
-			}
-		}
 	}
 
 	/* Move fence waiting after getting reservation lock of
@@ -642,13 +634,8 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 	}
 
 error_validate:
-	if (r) {
-		amdgpu_bo_list_for_each_entry(e, p->bo_list) {
-			dma_fence_chain_free(e->chain);
-			e->chain = NULL;
-		}
+	if (r)
 		ttm_eu_backoff_reservation(&p->ticket, &p->validated);
-	}
 out:
 	return r;
 }
@@ -688,17 +675,9 @@ static void amdgpu_cs_parser_fini(struct amdgpu_cs_parser *parser, int error,
 {
 	unsigned i;
 
-	if (error && backoff) {
-		struct amdgpu_bo_list_entry *e;
-
-		amdgpu_bo_list_for_each_entry(e, parser->bo_list) {
-			dma_fence_chain_free(e->chain);
-			e->chain = NULL;
-		}
-
+	if (error && backoff)
 		ttm_eu_backoff_reservation(&parser->ticket,
 					   &parser->validated);
-	}
 
 	for (i = 0; i < parser->num_post_deps; i++) {
 		drm_syncobj_put(parser->post_deps[i].syncobj);
@@ -1272,31 +1251,9 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
 
 	amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm);
 
-	amdgpu_bo_list_for_each_entry(e, p->bo_list) {
-		struct dma_resv *resv = e->tv.bo->base.resv;
-		struct dma_fence_chain *chain = e->chain;
-		struct dma_resv_iter cursor;
-		struct dma_fence *fence;
-
-		if (!chain)
-			continue;
-
-		/*
-		 * Temporary workaround dma_resv shortcommings by wrapping up
-		 * the submission in a dma_fence_chain and add it as exclusive
-		 * fence.
-		 *
-		 * TODO: Remove together with dma_resv rework.
-		 */
-		dma_resv_for_each_fence(&cursor, resv,
-					DMA_RESV_USAGE_WRITE,
-					fence) {
-			break;
-		}
-		dma_fence_chain_init(chain, fence, dma_fence_get(p->fence), 1);
-		rcu_assign_pointer(resv->fence_excl, &chain->base);
-		e->chain = NULL;
-	}
+	/* Make sure all BOs are remembered as writers */
+	amdgpu_bo_list_for_each_entry(e, p->bo_list)
+		e->tv.num_shared = 0;
 
 	ttm_eu_fence_buffer_objects(&p->ticket, &p->validated, p->fence);
 	mutex_unlock(&p->adev->notifier_lock);