dma-buf: rename and cleanup dma_resv_get_list v2

When the comment needs to state explicitly that this is doesn't get a reference
to the object then the function is named rather badly.

Rename the function and use it in even more places.

v2: use dma_resv_shared_list as new name

Signed-off-by: Christian König <[email protected]>
Acked-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: ChristianKoenigAMD

drivers/dma-buf/dma-resv.c

@@ -149,8 +149,7 @@ int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences)
 
 	dma_resv_assert_held(obj);
 
-	old = dma_resv_get_list(obj);
-
+	old = dma_resv_shared_list(obj);
 	if (old && old->shared_max) {
 		if ((old->shared_count + num_fences) <= old->shared_max)
 			return 0;
@@ -219,12 +218,13 @@ EXPORT_SYMBOL(dma_resv_reserve_shared);
  */
 void dma_resv_reset_shared_max(struct dma_resv *obj)
 {
-	/* Test shared fence slot reservation */
-	if (rcu_access_pointer(obj->fence)) {
-		struct dma_resv_list *fence = dma_resv_get_list(obj);
+	struct dma_resv_list *fences = dma_resv_shared_list(obj);
 
-		fence->shared_max = fence->shared_count;
-	}
+	dma_resv_assert_held(obj);
+
+	/* Test shared fence slot reservation */
+	if (fences)
+		fences->shared_max = fences->shared_count;
 }
 EXPORT_SYMBOL(dma_resv_reset_shared_max);
 #endif
@@ -247,7 +247,7 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence)
 
 	dma_resv_assert_held(obj);
 
-	fobj = dma_resv_get_list(obj);
+	fobj = dma_resv_shared_list(obj);
 	count = fobj->shared_count;
 
 	write_seqcount_begin(&obj->seq);
@@ -290,7 +290,7 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence)
 
 	dma_resv_assert_held(obj);
 
-	old = dma_resv_get_list(obj);
+	old = dma_resv_shared_list(obj);
 	if (old)
 		i = old->shared_count;
 
@@ -329,7 +329,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
 	dma_resv_assert_held(dst);
 
 	rcu_read_lock();
-	src_list = rcu_dereference(src->fence);
+	src_list = dma_resv_shared_list(src);
 
 retry:
 	if (src_list) {
@@ -342,7 +342,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
 			return -ENOMEM;
 
 		rcu_read_lock();
-		src_list = rcu_dereference(src->fence);
+		src_list = dma_resv_shared_list(src);
 		if (!src_list || src_list->shared_count > shared_count) {
 			kfree(dst_list);
 			goto retry;
@@ -360,7 +360,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
 
 			if (!dma_fence_get_rcu(fence)) {
 				dma_resv_list_free(dst_list);
-				src_list = rcu_dereference(src->fence);
+				src_list = dma_resv_shared_list(src);
 				goto retry;
 			}
 
@@ -379,7 +379,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
 	new = dma_fence_get_rcu_safe(&src->fence_excl);
 	rcu_read_unlock();
 
-	src_list = dma_resv_get_list(dst);
+	src_list = dma_resv_shared_list(dst);
 	old = dma_resv_excl_fence(dst);
 
 	write_seqcount_begin(&dst->seq);
@@ -432,7 +432,7 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj,
 		if (fence_excl && !dma_fence_get_rcu(fence_excl))
 			goto unlock;
 
-		fobj = rcu_dereference(obj->fence);
+		fobj = dma_resv_shared_list(obj);
 		if (fobj)
 			sz += sizeof(*shared) * fobj->shared_max;
 
@@ -538,7 +538,7 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj,
 	}
 
 	if (wait_all) {
-		struct dma_resv_list *fobj = rcu_dereference(obj->fence);
+		struct dma_resv_list *fobj = dma_resv_shared_list(obj);
 
 		if (fobj)
 			shared_count = fobj->shared_count;
@@ -623,7 +623,7 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
 	seq = read_seqcount_begin(&obj->seq);
 
 	if (test_all) {
-		struct dma_resv_list *fobj = rcu_dereference(obj->fence);
+		struct dma_resv_list *fobj = dma_resv_shared_list(obj);
 		unsigned int i;
 
 		if (fobj)

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

@@ -247,7 +247,7 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
 	if (!ef)
 		return -EINVAL;
 
-	old = dma_resv_get_list(resv);
+	old = dma_resv_shared_list(resv);
 	if (!old)
 		return 0;
 

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

@@ -49,7 +49,7 @@ __dma_resv_make_exclusive(struct dma_resv *obj)
 	unsigned int count;
 	int r;
 
-	if (!dma_resv_get_list(obj)) /* no shared fences to convert */
+	if (!dma_resv_shared_list(obj)) /* no shared fences to convert */
 		return 0;
 
 	r = dma_resv_get_fences_rcu(obj, NULL, &count, &fences);

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

@@ -213,7 +213,7 @@ int amdgpu_sync_resv(struct amdgpu_device *adev, struct amdgpu_sync *sync,
 	f = dma_resv_excl_fence(resv);
 	r = amdgpu_sync_fence(sync, f);
 
-	flist = dma_resv_get_list(resv);
+	flist = dma_resv_shared_list(resv);
 	if (!flist || r)
 		return r;
 

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

@@ -1339,7 +1339,7 @@ static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 	 * If true, then return false as any KFD process needs all its BOs to
 	 * be resident to run successfully
 	 */
-	flist = dma_resv_get_list(bo->base.resv);
+	flist = dma_resv_shared_list(bo->base.resv);
 	if (flist) {
 		for (i = 0; i < flist->shared_count; ++i) {
 			f = rcu_dereference_protected(flist->shared[i],

drivers/gpu/drm/etnaviv/etnaviv_gem.c

@@ -461,7 +461,7 @@ static void etnaviv_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 			off, etnaviv_obj->vaddr, obj->size);
 
 	rcu_read_lock();
-	fobj = rcu_dereference(robj->fence);
+	fobj = dma_resv_shared_list(robj);
 	if (fobj) {
 		unsigned int i, shared_count = fobj->shared_count;
 

drivers/gpu/drm/i915/gem/i915_gem_busy.c

@@ -116,7 +116,7 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 	args->busy = busy_check_writer(dma_resv_excl_fence(obj->base.resv));
 
 	/* Translate shared fences to READ set of engines */
-	list = rcu_dereference(obj->base.resv->fence);
+	list = dma_resv_shared_list(obj->base.resv);
 	if (list) {
 		unsigned int shared_count = list->shared_count, i;
 

drivers/gpu/drm/msm/msm_gem.c

@@ -817,7 +817,7 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
 	struct dma_fence *fence;
 	int i, ret;
 
-	fobj = dma_resv_get_list(obj->resv);
+	fobj = dma_resv_shared_list(obj->resv);
 	if (!fobj || (fobj->shared_count == 0)) {
 		fence = dma_resv_excl_fence(obj->resv);
 		/* don't need to wait on our own fences, since ring is fifo */
@@ -1025,7 +1025,7 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m,
 	}
 
 	rcu_read_lock();
-	fobj = rcu_dereference(robj->fence);
+	fobj = dma_resv_shared_list(robj);
 	if (fobj) {
 		unsigned int i, shared_count = fobj->shared_count;
 

drivers/gpu/drm/nouveau/nouveau_fence.c

@@ -355,7 +355,7 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e
 			return ret;
 	}
 
-	fobj = dma_resv_get_list(resv);
+	fobj = dma_resv_shared_list(resv);
 	fence = dma_resv_excl_fence(resv);
 
 	if (fence && (!exclusive || !fobj || !fobj->shared_count)) {

drivers/gpu/drm/qxl/qxl_debugfs.c

@@ -61,7 +61,7 @@ qxl_debugfs_buffers_info(struct seq_file *m, void *data)
 		int rel;
 
 		rcu_read_lock();
-		fobj = rcu_dereference(bo->tbo.base.resv->fence);
+		fobj = dma_resv_shared_list(bo->tbo.base.resv);
 		rel = fobj ? fobj->shared_count : 0;
 		rcu_read_unlock();
 

drivers/gpu/drm/radeon/radeon_sync.c

@@ -105,7 +105,7 @@ int radeon_sync_resv(struct radeon_device *rdev,
 	else if (f)
 		r = dma_fence_wait(f, true);
 
-	flist = dma_resv_get_list(resv);
+	flist = dma_resv_shared_list(resv);
 	if (shared || !flist || r)
 		return r;
 

drivers/gpu/drm/ttm/ttm_bo.c

@@ -261,7 +261,7 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
 	int i;
 
 	rcu_read_lock();
-	fobj = rcu_dereference(resv->fence);
+	fobj = dma_resv_shared_list(resv);
 	fence = dma_resv_excl_fence(resv);
 	if (fence && !fence->ops->signaled)
 		dma_fence_enable_sw_signaling(fence);

include/linux/dma-resv.h

@@ -78,20 +78,6 @@ struct dma_resv {
 #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
 #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
 
-/**
- * dma_resv_get_list - get the reservation object's
- * shared fence list, with update-side lock held
- * @obj: the reservation object
- *
- * Returns the shared fence list.  Does NOT take references to
- * the fence.  The obj->lock must be held.
- */
-static inline struct dma_resv_list *dma_resv_get_list(struct dma_resv *obj)
-{
-	return rcu_dereference_protected(obj->fence,
-					 dma_resv_held(obj));
-}
-
 #ifdef CONFIG_DEBUG_MUTEXES
 void dma_resv_reset_shared_max(struct dma_resv *obj);
 #else
@@ -268,6 +254,19 @@ dma_resv_get_excl_rcu(struct dma_resv *obj)
 	return fence;
 }
 
+/**
+ * dma_resv_shared_list - get the reservation object's shared fence list
+ * @obj: the reservation object
+ *
+ * Returns the shared fence list. Caller must either hold the objects
+ * through dma_resv_lock() or the RCU read side lock through rcu_read_lock(),
+ * or one of the variants of each
+ */
+static inline struct dma_resv_list *dma_resv_shared_list(struct dma_resv *obj)
+{
+	return rcu_dereference_check(obj->fence, dma_resv_held(obj));
+}
+
 void dma_resv_init(struct dma_resv *obj);
 void dma_resv_fini(struct dma_resv *obj);
 int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences);