dma-buf: rename and cleanup dma_resv_get_excl v3

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

Rename the function and use rcu_dereference_check(), this
way it can be used from both rcu as well as lock protected
critical sections.

v2: improve kerneldoc as suggested by Daniel
v3: use dma_resv_excl_fence as function name

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20210602111714.212426-4-christian.koenig@amd.com

12 files changed, 13 insertions, 14 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 73c76a3e2b12..7d5aaf584634 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -226,7 +226,7 @@ static void amdgpu_gem_object_close(struct drm_gem_object *obj,
 	if (!amdgpu_vm_ready(vm))
 		goto out_unlock;
 
-	fence = dma_resv_get_excl(bo->tbo.base.resv);
+	fence = dma_resv_excl_fence(bo->tbo.base.resv);
 	if (fence) {
 		amdgpu_bo_fence(bo, fence, true);
 		fence = NULL;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
index 4e558632a5d2..2bdc9df5c6b9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
@@ -210,7 +210,7 @@ int amdgpu_sync_resv(struct amdgpu_device *adev, struct amdgpu_sync *sync,
 		return -EINVAL;
 
 	/* always sync to the exclusive fence */
-	f = dma_resv_get_excl(resv);
+	f = dma_resv_excl_fence(resv);
 	r = amdgpu_sync_fence(sync, f);
 
 	flist = dma_resv_get_list(resv);
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index db69f19ab5bc..2237fe5204d0 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -471,7 +471,7 @@ static void etnaviv_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 		}
 	}
 
-	fence = rcu_dereference(robj->fence_excl);
+	fence = dma_resv_excl_fence(robj);
 	if (fence)
 		etnaviv_gem_describe_fence(fence, "Exclusive", m);
 	rcu_read_unlock();
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
index 25235ef630c1..088d375b3395 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
@@ -113,8 +113,7 @@ retry:
 	seq = raw_read_seqcount(&obj->base.resv->seq);
 
 	/* Translate the exclusive fence to the READ *and* WRITE engine */
-	args->busy =
-		busy_check_writer(rcu_dereference(obj->base.resv->fence_excl));
+	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);
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 56df86e5f740..a5a2a922e3e8 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -819,7 +819,7 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
 
 	fobj = dma_resv_get_list(obj->resv);
 	if (!fobj || (fobj->shared_count == 0)) {
-		fence = dma_resv_get_excl(obj->resv);
+		fence = dma_resv_excl_fence(obj->resv);
 		/* don't need to wait on our own fences, since ring is fifo */
 		if (fence && (fence->context != fctx->context)) {
 			ret = dma_fence_wait(fence, true);
@@ -1035,7 +1035,7 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m,
 		}
 	}
 
-	fence = rcu_dereference(robj->fence_excl);
+	fence = dma_resv_excl_fence(robj);
 	if (fence)
 		describe_fence(fence, "Exclusive", m);
 	rcu_read_unlock();
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index c3d20bc80022..520b1ea9d16c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -951,7 +951,7 @@ nouveau_bo_vm_cleanup(struct ttm_buffer_object *bo,
 {
 	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
 	struct drm_device *dev = drm->dev;
-	struct dma_fence *fence = dma_resv_get_excl(bo->base.resv);
+	struct dma_fence *fence = dma_resv_excl_fence(bo->base.resv);
 
 	nv10_bo_put_tile_region(dev, *old_tile, fence);
 	*old_tile = new_tile;
diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c
index e5dcbf67de7e..19c096de5bdc 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fence.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
@@ -356,7 +356,7 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e
 	}
 
 	fobj = dma_resv_get_list(resv);
-	fence = dma_resv_get_excl(resv);
+	fence = dma_resv_excl_fence(resv);
 
 	if (fence && (!exclusive || !fobj || !fobj->shared_count)) {
 		struct nouveau_channel *prev = NULL;
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 652af7a134bd..406681317419 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -533,7 +533,7 @@ static int radeon_crtc_page_flip_target(struct drm_crtc *crtc,
 		DRM_ERROR("failed to pin new rbo buffer before flip\n");
 		goto cleanup;
 	}
-	work->fence = dma_fence_get(dma_resv_get_excl(new_rbo->tbo.base.resv));
+	work->fence = dma_fence_get(dma_resv_excl_fence(new_rbo->tbo.base.resv));
 	radeon_bo_get_tiling_flags(new_rbo, &tiling_flags, NULL);
 	radeon_bo_unreserve(new_rbo);
 
diff --git a/drivers/gpu/drm/radeon/radeon_sync.c b/drivers/gpu/drm/radeon/radeon_sync.c
index 5d3302945076..c8a1711325de 100644
--- a/drivers/gpu/drm/radeon/radeon_sync.c
+++ b/drivers/gpu/drm/radeon/radeon_sync.c
@@ -98,7 +98,7 @@ int radeon_sync_resv(struct radeon_device *rdev,
 	int r = 0;
 
 	/* always sync to the exclusive fence */
-	f = dma_resv_get_excl(resv);
+	f = dma_resv_excl_fence(resv);
 	fence = f ? to_radeon_fence(f) : NULL;
 	if (fence && fence->rdev == rdev)
 		radeon_sync_fence(sync, fence);
diff --git a/drivers/gpu/drm/radeon/radeon_uvd.c b/drivers/gpu/drm/radeon/radeon_uvd.c
index dfa9fdbe98da..1f5b1a5c0a09 100644
--- a/drivers/gpu/drm/radeon/radeon_uvd.c
+++ b/drivers/gpu/drm/radeon/radeon_uvd.c
@@ -477,7 +477,7 @@ static int radeon_uvd_cs_msg(struct radeon_cs_parser *p, struct radeon_bo *bo,
 		return -EINVAL;
 	}
 
-	f = dma_resv_get_excl(bo->tbo.base.resv);
+	f = dma_resv_excl_fence(bo->tbo.base.resv);
 	if (f) {
 		r = radeon_fence_wait((struct radeon_fence *)f, false);
 		if (r) {
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 4ed56520b81d..1752f8e523e7 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -262,7 +262,7 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
 
 	rcu_read_lock();
 	fobj = rcu_dereference(resv->fence);
-	fence = rcu_dereference(resv->fence_excl);
+	fence = dma_resv_excl_fence(resv);
 	if (fence && !fence->ops->signaled)
 		dma_fence_enable_sw_signaling(fence);
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index 62ea920addc3..7b45393ad98e 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -1166,7 +1166,7 @@ int vmw_resources_clean(struct vmw_buffer_object *vbo, pgoff_t start,
 		if (bo->moving)
 			dma_fence_put(bo->moving);
 		bo->moving = dma_fence_get
-			(dma_resv_get_excl(bo->base.resv));
+			(dma_resv_excl_fence(bo->base.resv));
 	}
 
 	return 0;