dma-buf: drop excl_fence parameter from dma_resv_get_fences

Returning the exclusive fence separately is no longer used.

Instead add a write parameter to indicate the use case.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211207123411.167006-4-christian.koenig@amd.com

drivers/dma-buf/dma-resv.c

@@ -542,57 +542,45 @@ EXPORT_SYMBOL(dma_resv_copy_fences);
  * dma_resv_get_fences - Get an object's shared and exclusive
  * fences without update side lock held
  * @obj: the reservation object
- * @fence_excl: the returned exclusive fence (or NULL)
- * @shared_count: the number of shared fences returned
- * @shared: the array of shared fence ptrs returned (array is krealloc'd to
- * the required size, and must be freed by caller)
+ * @write: true if we should return all fences
+ * @num_fences: the number of fences returned
+ * @fences: the array of fence ptrs returned (array is krealloc'd to the
+ * required size, and must be freed by caller)
  *
- * Retrieve all fences from the reservation object. If the pointer for the
- * exclusive fence is not specified the fence is put into the array of the
- * shared fences as well. Returns either zero or -ENOMEM.
+ * Retrieve all fences from the reservation object.
+ * Returns either zero or -ENOMEM.
  */
-int dma_resv_get_fences(struct dma_resv *obj, struct dma_fence **fence_excl,
-			unsigned int *shared_count, struct dma_fence ***shared)
+int dma_resv_get_fences(struct dma_resv *obj, bool write,
+			unsigned int *num_fences, struct dma_fence ***fences)
 {
 	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
 
-	*shared_count = 0;
-	*shared = NULL;
+	*num_fences = 0;
+	*fences = NULL;
 
-	if (fence_excl)
-		*fence_excl = NULL;
-
-	dma_resv_iter_begin(&cursor, obj, true);
+	dma_resv_iter_begin(&cursor, obj, write);
 	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 
 		if (dma_resv_iter_is_restarted(&cursor)) {
 			unsigned int count;
 
-			while (*shared_count)
-				dma_fence_put((*shared)[--(*shared_count)]);
-
-			if (fence_excl)
-				dma_fence_put(*fence_excl);
+			while (*num_fences)
+				dma_fence_put((*fences)[--(*num_fences)]);
 
-			count = cursor.shared_count;
-			count += fence_excl ? 0 : 1;
+			count = cursor.shared_count + 1;
 
 			/* Eventually re-allocate the array */
-			*shared = krealloc_array(*shared, count,
+			*fences = krealloc_array(*fences, count,
 						 sizeof(void *),
 						 GFP_KERNEL);
-			if (count && !*shared) {
+			if (count && !*fences) {
 				dma_resv_iter_end(&cursor);
 				return -ENOMEM;
 			}
 		}
 
-		dma_fence_get(fence);
-		if (dma_resv_iter_is_exclusive(&cursor) && fence_excl)
-			*fence_excl = fence;
-		else
-			(*shared)[(*shared_count)++] = fence;
+		(*fences)[(*num_fences)++] = dma_fence_get(fence);
 	}
 	dma_resv_iter_end(&cursor);
 

drivers/dma-buf/st-dma-resv.c

@@ -275,7 +275,7 @@ static int test_shared_for_each_unlocked(void *arg)
 
 static int test_get_fences(void *arg, bool shared)
 {
-	struct dma_fence *f, *excl = NULL, **fences = NULL;
+	struct dma_fence *f, **fences = NULL;
 	struct dma_resv resv;
 	int r, i;
 
@@ -304,35 +304,19 @@ static int test_get_fences(void *arg, bool shared)
 	}
 	dma_resv_unlock(&resv);
 
-	r = dma_resv_get_fences(&resv, &excl, &i, &fences);
+	r = dma_resv_get_fences(&resv, shared, &i, &fences);
 	if (r) {
 		pr_err("get_fences failed\n");
 		goto err_free;
 	}
 
-	if (shared) {
-		if (excl != NULL) {
-			pr_err("get_fences returned unexpected excl fence\n");
-			goto err_free;
-		}
-		if (i != 1 || fences[0] != f) {
-			pr_err("get_fences returned unexpected shared fence\n");
-			goto err_free;
-		}
-	} else {
-		if (excl != f) {
-			pr_err("get_fences returned unexpected excl fence\n");
-			goto err_free;
-		}
-		if (i != 0) {
-			pr_err("get_fences returned unexpected shared fence\n");
-			goto err_free;
-		}
+	if (i != 1 || fences[0] != f) {
+		pr_err("get_fences returned unexpected fence\n");
+		goto err_free;
 	}
 
 	dma_fence_signal(f);
 err_free:
-	dma_fence_put(excl);
 	while (i--)
 		dma_fence_put(fences[i]);
 	kfree(fences);

drivers/gpu/drm/amd/amdgpu/amdgpu_display.c

@@ -200,8 +200,10 @@ int amdgpu_display_crtc_page_flip_target(struct drm_crtc *crtc,
 		goto unpin;
 	}
 
-	r = dma_resv_get_fences(new_abo->tbo.base.resv, NULL,
-				&work->shared_count, &work->shared);
+	/* TODO: Unify this with other drivers */
+	r = dma_resv_get_fences(new_abo->tbo.base.resv, true,
+				&work->shared_count,
+				&work->shared);
 	if (unlikely(r != 0)) {
 		DRM_ERROR("failed to get fences for buffer\n");
 		goto unpin;

drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c

@@ -112,7 +112,7 @@ void amdgpu_pasid_free_delayed(struct dma_resv *resv,
 	unsigned count;
 	int r;
 
-	r = dma_resv_get_fences(resv, NULL, &count, &fences);
+	r = dma_resv_get_fences(resv, true, &count, &fences);
 	if (r)
 		goto fallback;
 

drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c

@@ -189,8 +189,7 @@ static int submit_fence_sync(struct etnaviv_gem_submit *submit)
 			continue;
 
 		if (bo->flags & ETNA_SUBMIT_BO_WRITE) {
-			ret = dma_resv_get_fences(robj, NULL,
-						  &bo->nr_shared,
+			ret = dma_resv_get_fences(robj, true, &bo->nr_shared,
 						  &bo->shared);
 			if (ret)
 				return ret;

include/linux/dma-resv.h

@@ -458,8 +458,8 @@ void dma_resv_fini(struct dma_resv *obj);
 int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences);
 void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence);
 void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence);
-int dma_resv_get_fences(struct dma_resv *obj, struct dma_fence **pfence_excl,
-			unsigned *pshared_count, struct dma_fence ***pshared);
+int dma_resv_get_fences(struct dma_resv *obj, bool write,
+			unsigned int *num_fences, struct dma_fence ***fences);
 int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src);
 long dma_resv_wait_timeout(struct dma_resv *obj, bool wait_all, bool intr,
 			   unsigned long timeout);