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.
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/dma-buf/dma-buf.c | 4 ++-- drivers/dma-buf/dma-resv.c | 10 +++++----- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 2 +- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +- drivers/gpu/drm/i915/gem/i915_gem_busy.c | 3 +-- drivers/gpu/drm/msm/msm_gem.c | 4 ++-- drivers/gpu/drm/nouveau/nouveau_bo.c | 2 +- drivers/gpu/drm/nouveau/nouveau_fence.c | 2 +- drivers/gpu/drm/radeon/radeon_display.c | 2 +- drivers/gpu/drm/radeon/radeon_sync.c | 2 +- drivers/gpu/drm/radeon/radeon_uvd.c | 2 +- drivers/gpu/drm/ttm/ttm_bo.c | 2 +- drivers/gpu/drm/vmwgfx/vmwgfx_resource.c | 2 +- include/linux/dma-resv.h | 13 +++++-------- 15 files changed, 25 insertions(+), 29 deletions(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 468c282b8a06..5abf6b8c89ac 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -234,7 +234,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) shared_count = fobj->shared_count; else shared_count = 0; - fence_excl = rcu_dereference(resv->fence_excl); + fence_excl = dma_resv_exclusive(resv); if (read_seqcount_retry(&resv->seq, seq)) { rcu_read_unlock(); goto retry; @@ -1385,7 +1385,7 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) robj = buf_obj->resv; seq = read_seqcount_begin(&robj->seq); rcu_read_lock(); - fence = rcu_dereference(robj->fence_excl); + fence = dma_resv_exclusive(robj); if (fence) seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", fence->ops->get_driver_name(fence), diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 6c6195315e9f..81b032b43457 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -281,7 +281,7 @@ EXPORT_SYMBOL(dma_resv_add_shared_fence); */ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence) { - struct dma_fence *old_fence = dma_resv_get_excl(obj); + struct dma_fence *old_fence = dma_resv_exclusive(obj); struct dma_resv_list *old; u32 i = 0;
@@ -377,7 +377,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src) rcu_read_unlock();
src_list = dma_resv_get_list(dst); - old = dma_resv_get_excl(dst); + old = dma_resv_exclusive(dst);
write_seqcount_begin(&dst->seq); /* write_seqcount_begin provides the necessary memory barrier */ @@ -425,7 +425,7 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, rcu_read_lock(); seq = read_seqcount_begin(&obj->seq);
- fence_excl = rcu_dereference(obj->fence_excl); + fence_excl = dma_resv_exclusive(obj); if (fence_excl && !dma_fence_get_rcu(fence_excl)) goto unlock;
@@ -520,7 +520,7 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj, rcu_read_lock(); i = -1;
- fence = rcu_dereference(obj->fence_excl); + fence = dma_resv_exclusive(obj); if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { if (!dma_fence_get_rcu(fence)) goto unlock_retry; @@ -642,7 +642,7 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all) }
if (!shared_count) { - struct dma_fence *fence_excl = rcu_dereference(obj->fence_excl); + struct dma_fence *fence_excl = dma_resv_exclusive(obj);
if (fence_excl) { ret = dma_resv_test_signaled_single(fence_excl); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 18974bd081f0..94da44d97e7f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -185,7 +185,7 @@ 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_exclusive(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..c84d5b843985 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_exclusive(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..d4f54dea8ac1 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_exclusive(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..02312a0c3a36 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 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, 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_exclusive(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 b199942266a2..99b8cefb0072 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -805,7 +805,7 @@ 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_exclusive(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); @@ -1021,7 +1021,7 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m, } }
- fence = rcu_dereference(robj->fence_excl); + fence = dma_resv_exclusive(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 7a2624c0ba4c..ad30a6a100b9 100644 --- a/drivers/gpu/drm/nouveau/nouveau_bo.c +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c @@ -955,7 +955,7 @@ 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_exclusive(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..a6cb35181aee 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_exclusive(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..57c910e5ae77 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_exclusive(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..e476f90ef1c1 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_exclusive(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..02d4bbdc9111 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_exclusive(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 ca1b098b6a56..95fa73ef90fb 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -260,7 +260,7 @@ 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_exclusive(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..c78f38ee1c20 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_exclusive(bo->base.resv)); }
return 0; diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index f32a3d176513..7549ec5eb35c 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -226,22 +226,19 @@ static inline void dma_resv_unlock(struct dma_resv *obj) }
/** - * dma_resv_get_excl - get the reservation object's - * exclusive fence, with update-side lock held + * dma_resv_exclusive - return the object's exclusive fence * @obj: the reservation object * - * Returns the exclusive fence (if any). Does NOT take a - * reference. Writers must hold obj->lock, readers may only - * hold a RCU read side lock. + * Returns the exclusive fence (if any). Caller must either hold the objects + * lock or the rcu read side lock. * * RETURNS * The exclusive fence or NULL */ static inline struct dma_fence * -dma_resv_get_excl(struct dma_resv *obj) +dma_resv_exclusive(struct dma_resv *obj) { - return rcu_dereference_protected(obj->fence_excl, - dma_resv_held(obj)); + return rcu_dereference_check(obj->fence_excl, dma_resv_held(obj)); }
/**