[PATCH v2] drm/ttm: kill fence_lock

[Maarten Lankhorst <maarten.lankhorst@canonical.com>]

No users are left, kill it off! :D

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
---
Fixed to apply on top of drm-next.

Also, for nouveau "[PATCH 1/2] drm/nouveau: hold mutex while syncing to kernel channel"
is required, else this patch will fail to apply.

  drivers/gpu/drm/nouveau/nouveau_bo.c      | 23 ++++------
  drivers/gpu/drm/nouveau/nouveau_display.c |  6 +--
  drivers/gpu/drm/nouveau/nouveau_gem.c     | 16 +------
  drivers/gpu/drm/qxl/qxl_cmd.c             |  2 -
  drivers/gpu/drm/qxl/qxl_fence.c           |  4 --
  drivers/gpu/drm/qxl/qxl_object.h          |  2 -
  drivers/gpu/drm/qxl/qxl_release.c         |  2 -
  drivers/gpu/drm/radeon/radeon_display.c   |  2 -
  drivers/gpu/drm/radeon/radeon_object.c    |  2 -
  drivers/gpu/drm/ttm/ttm_bo.c              | 75 ++++++++-----------------------
  drivers/gpu/drm/ttm/ttm_bo_util.c         |  5 ---
  drivers/gpu/drm/ttm/ttm_bo_vm.c           |  3 --
  drivers/gpu/drm/ttm/ttm_execbuf_util.c    |  2 -
  drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c    |  4 --
  drivers/gpu/drm/vmwgfx/vmwgfx_resource.c  | 16 +++----
  include/drm/ttm/ttm_bo_api.h              |  5 +--
  include/drm/ttm/ttm_bo_driver.h           |  3 --
  17 files changed, 36 insertions(+), 136 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 38444ba22f0d..8e760b74cf0b 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1454,26 +1454,19 @@ nouveau_ttm_tt_unpopulate(struct ttm_tt *ttm)
  	ttm_pool_unpopulate(ttm);
  }
  
+static void
+nouveau_bo_fence_unref(void **sync_obj)
+{
+	nouveau_fence_unref((struct nouveau_fence **)sync_obj);
+}
+
  void
  nouveau_bo_fence(struct nouveau_bo *nvbo, struct nouveau_fence *fence)
  {
-	struct nouveau_fence *new_fence = nouveau_fence_ref(fence);
-	struct nouveau_fence *old_fence = NULL;
-
  	lockdep_assert_held(&nvbo->bo.resv->lock.base);
  
-	spin_lock(&nvbo->bo.bdev->fence_lock);
-	old_fence = nvbo->bo.sync_obj;
-	nvbo->bo.sync_obj = new_fence;
-	spin_unlock(&nvbo->bo.bdev->fence_lock);
-
-	nouveau_fence_unref(&old_fence);
-}
-
-static void
-nouveau_bo_fence_unref(void **sync_obj)
-{
-	nouveau_fence_unref((struct nouveau_fence **)sync_obj);
+	nouveau_bo_fence_unref(&nvbo->bo.sync_obj);
+	nvbo->bo.sync_obj = nouveau_fence_ref(fence);
  }
  
  static void *
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index 9d3892a1af96..e3117c78ea95 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -615,11 +615,7 @@ nouveau_crtc_page_flip(struct drm_crtc *crtc, struct drm_framebuffer *fb,
  		goto fail_unpin;
  
  	/* synchronise rendering channel with the kernel's channel */
-	spin_lock(&new_bo->bo.bdev->fence_lock);
-	fence = nouveau_fence_ref(new_bo->bo.sync_obj);
-	spin_unlock(&new_bo->bo.bdev->fence_lock);
-	ret = nouveau_fence_sync(fence, chan);
-	nouveau_fence_unref(&fence);
+	ret = nouveau_fence_sync(new_bo->bo.sync_obj, chan);
  
  	if (ret) {
  		ttm_bo_unreserve(&new_bo->bo);
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 0e35aafc628e..e15178a5893b 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -105,9 +105,7 @@ nouveau_gem_object_unmap(struct nouveau_bo *nvbo, struct nouveau_vma *vma)
  	list_del(&vma->head);
  
  	if (mapped) {
-		spin_lock(&nvbo->bo.bdev->fence_lock);
  		fence = nouveau_fence_ref(nvbo->bo.sync_obj);
-		spin_unlock(&nvbo->bo.bdev->fence_lock);
  	}
  
  	if (fence) {
@@ -434,17 +432,11 @@ retry:
  static int
  validate_sync(struct nouveau_channel *chan, struct nouveau_bo *nvbo)
  {
-	struct nouveau_fence *fence = NULL;
+	struct nouveau_fence *fence = nvbo->bo.sync_obj;
  	int ret = 0;
  
-	spin_lock(&nvbo->bo.bdev->fence_lock);
-	fence = nouveau_fence_ref(nvbo->bo.sync_obj);
-	spin_unlock(&nvbo->bo.bdev->fence_lock);
-
-	if (fence) {
+	if (fence)
  		ret = nouveau_fence_sync(fence, chan);
-		nouveau_fence_unref(&fence);
-	}
  
  	return ret;
  }
@@ -669,9 +661,7 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
  				data |= r->vor;
  		}
  
-		spin_lock(&nvbo->bo.bdev->fence_lock);
  		ret = ttm_bo_wait(&nvbo->bo, false, false, false);
-		spin_unlock(&nvbo->bo.bdev->fence_lock);
  		if (ret) {
  			NV_ERROR(cli, "reloc wait_idle failed: %d\n", ret);
  			break;
@@ -904,11 +894,9 @@ nouveau_gem_ioctl_cpu_prep(struct drm_device *dev, void *data,
  
  	ret = ttm_bo_reserve(&nvbo->bo, true, false, false, 0);
  	if (!ret) {
-		spin_lock(&nvbo->bo.bdev->fence_lock);
  		ret = ttm_bo_wait(&nvbo->bo, true, true, true);
  		if (!no_wait && ret)
  			fence = nouveau_fence_ref(nvbo->bo.sync_obj);
-		spin_unlock(&nvbo->bo.bdev->fence_lock);
  
  		ttm_bo_unreserve(&nvbo->bo);
  	}
diff --git a/drivers/gpu/drm/qxl/qxl_cmd.c b/drivers/gpu/drm/qxl/qxl_cmd.c
index eb89653a7a17..45fad7b45486 100644
--- a/drivers/gpu/drm/qxl/qxl_cmd.c
+++ b/drivers/gpu/drm/qxl/qxl_cmd.c
@@ -628,9 +628,7 @@ static int qxl_reap_surf(struct qxl_device *qdev, struct qxl_bo *surf, bool stal
  	if (stall)
  		mutex_unlock(&qdev->surf_evict_mutex);
  
-	spin_lock(&surf->tbo.bdev->fence_lock);
  	ret = ttm_bo_wait(&surf->tbo, true, true, !stall);
-	spin_unlock(&surf->tbo.bdev->fence_lock);
  
  	if (stall)
  		mutex_lock(&qdev->surf_evict_mutex);
diff --git a/drivers/gpu/drm/qxl/qxl_fence.c b/drivers/gpu/drm/qxl/qxl_fence.c
index ae59e91cfb9a..c7248418117d 100644
--- a/drivers/gpu/drm/qxl/qxl_fence.c
+++ b/drivers/gpu/drm/qxl/qxl_fence.c
@@ -60,9 +60,6 @@ int qxl_fence_remove_release(struct qxl_fence *qfence, uint32_t rel_id)
  {
  	void *ret;
  	int retval = 0;
-	struct qxl_bo *bo = container_of(qfence, struct qxl_bo, fence);
-
-	spin_lock(&bo->tbo.bdev->fence_lock);
  
  	ret = radix_tree_delete(&qfence->tree, rel_id);
  	if (ret == qfence)
@@ -71,7 +68,6 @@ int qxl_fence_remove_release(struct qxl_fence *qfence, uint32_t rel_id)
  		DRM_DEBUG("didn't find fence in radix tree for %d\n", rel_id);
  		retval = -ENOENT;
  	}
-	spin_unlock(&bo->tbo.bdev->fence_lock);
  	return retval;
  }
  
diff --git a/drivers/gpu/drm/qxl/qxl_object.h b/drivers/gpu/drm/qxl/qxl_object.h
index d458a140c024..98395b223ad0 100644
--- a/drivers/gpu/drm/qxl/qxl_object.h
+++ b/drivers/gpu/drm/qxl/qxl_object.h
@@ -76,12 +76,10 @@ static inline int qxl_bo_wait(struct qxl_bo *bo, u32 *mem_type,
  		}
  		return r;
  	}
-	spin_lock(&bo->tbo.bdev->fence_lock);
  	if (mem_type)
  		*mem_type = bo->tbo.mem.mem_type;
  	if (bo->tbo.sync_obj)
  		r = ttm_bo_wait(&bo->tbo, true, true, no_wait);
-	spin_unlock(&bo->tbo.bdev->fence_lock);
  	ttm_bo_unreserve(&bo->tbo);
  	return r;
  }
diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c
index 6f71cadc7c9b..44f43e6adc81 100644
--- a/drivers/gpu/drm/qxl/qxl_release.c
+++ b/drivers/gpu/drm/qxl/qxl_release.c
@@ -337,7 +337,6 @@ void qxl_release_fence_buffer_objects(struct qxl_release *release)
  	glob = bo->glob;
  
  	spin_lock(&glob->lru_lock);
-	spin_lock(&bdev->fence_lock);
  
  	list_for_each_entry(entry, &release->bos, head) {
  		bo = entry->bo;
@@ -351,7 +350,6 @@ void qxl_release_fence_buffer_objects(struct qxl_release *release)
  		ttm_bo_add_to_lru(bo);
  		ww_mutex_unlock(&bo->resv->lock);
  	}
-	spin_unlock(&bdev->fence_lock);
  	spin_unlock(&glob->lru_lock);
  	ww_acquire_fini(&release->ticket);
  }
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 7ea647b84733..b62ba6f6507c 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -380,10 +380,8 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
  	obj = new_radeon_fb->obj;
  	rbo = gem_to_radeon_bo(obj);
  
-	spin_lock(&rbo->tbo.bdev->fence_lock);
  	if (rbo->tbo.sync_obj)
  		work->fence = radeon_fence_ref(rbo->tbo.sync_obj);
-	spin_unlock(&rbo->tbo.bdev->fence_lock);
  
  	INIT_WORK(&work->work, radeon_unpin_work_func);
  
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index ffc5496cea2d..a2be41a21803 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -612,12 +612,10 @@ int radeon_bo_wait(struct radeon_bo *bo, u32 *mem_type, bool no_wait)
  	r = ttm_bo_reserve(&bo->tbo, true, no_wait, false, 0);
  	if (unlikely(r != 0))
  		return r;
-	spin_lock(&bo->tbo.bdev->fence_lock);
  	if (mem_type)
  		*mem_type = bo->tbo.mem.mem_type;
  	if (bo->tbo.sync_obj)
  		r = ttm_bo_wait(&bo->tbo, true, true, no_wait);
-	spin_unlock(&bo->tbo.bdev->fence_lock);
  	ttm_bo_unreserve(&bo->tbo);
  	return r;
  }
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index b2b38b52f449..2c0528aba01c 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -412,24 +412,20 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
  	spin_lock(&glob->lru_lock);
  	ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);
  
-	spin_lock(&bdev->fence_lock);
-	(void) ttm_bo_wait(bo, false, false, true);
-	if (!ret && !bo->sync_obj) {
-		spin_unlock(&bdev->fence_lock);
-		put_count = ttm_bo_del_from_lru(bo);
+	if (!ret) {
+		(void) ttm_bo_wait(bo, false, false, true);
  
-		spin_unlock(&glob->lru_lock);
-		ttm_bo_cleanup_memtype_use(bo);
+		if (!bo->sync_obj) {
+			put_count = ttm_bo_del_from_lru(bo);
  
-		ttm_bo_list_ref_sub(bo, put_count, true);
+			spin_unlock(&glob->lru_lock);
+			ttm_bo_cleanup_memtype_use(bo);
  
-		return;
-	}
-	if (bo->sync_obj)
-		sync_obj = driver->sync_obj_ref(bo->sync_obj);
-	spin_unlock(&bdev->fence_lock);
+			ttm_bo_list_ref_sub(bo, put_count, true);
  
-	if (!ret) {
+			return;
+		}
+		sync_obj = driver->sync_obj_ref(bo->sync_obj);
  
  		/*
  		 * Make NO_EVICT bos immediately available to
@@ -478,7 +474,6 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
  	int put_count;
  	int ret;
  
-	spin_lock(&bdev->fence_lock);
  	ret = ttm_bo_wait(bo, false, false, true);
  
  	if (ret && !no_wait_gpu) {
@@ -490,7 +485,6 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
  		 * no new sync objects can be attached.
  		 */
  		sync_obj = driver->sync_obj_ref(bo->sync_obj);
-		spin_unlock(&bdev->fence_lock);
  
  		ww_mutex_unlock(&bo->resv->lock);
  		spin_unlock(&glob->lru_lock);
@@ -520,11 +514,9 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
  		 * remove sync_obj with ttm_bo_wait, the wait should be
  		 * finished, and no new wait object should have been added.
  		 */
-		spin_lock(&bdev->fence_lock);
  		ret = ttm_bo_wait(bo, false, false, true);
  		WARN_ON(ret);
  	}
-	spin_unlock(&bdev->fence_lock);
  
  	if (ret || unlikely(list_empty(&bo->ddestroy))) {
  		ww_mutex_unlock(&bo->resv->lock);
@@ -662,9 +654,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
  	struct ttm_placement placement;
  	int ret = 0;
  
-	spin_lock(&bdev->fence_lock);
  	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
-	spin_unlock(&bdev->fence_lock);
  
  	if (unlikely(ret != 0)) {
  		if (ret != -ERESTARTSYS) {
@@ -961,7 +951,6 @@ static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
  {
  	int ret = 0;
  	struct ttm_mem_reg mem;
-	struct ttm_bo_device *bdev = bo->bdev;
  
  	lockdep_assert_held(&bo->resv->lock.base);
  
@@ -970,9 +959,7 @@ static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
  	 * Have the driver move function wait for idle when necessary,
  	 * instead of doing it here.
  	 */
-	spin_lock(&bdev->fence_lock);
  	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
-	spin_unlock(&bdev->fence_lock);
  	if (ret)
  		return ret;
  	mem.num_pages = bo->num_pages;
@@ -1471,7 +1458,6 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
  	bdev->glob = glob;
  	bdev->need_dma32 = need_dma32;
  	bdev->val_seq = 0;
-	spin_lock_init(&bdev->fence_lock);
  	mutex_lock(&glob->device_list_mutex);
  	list_add_tail(&bdev->device_list, &glob->device_list);
  	mutex_unlock(&glob->device_list_mutex);
@@ -1529,7 +1515,6 @@ int ttm_bo_wait(struct ttm_buffer_object *bo,
  		bool lazy, bool interruptible, bool no_wait)
  {
  	struct ttm_bo_driver *driver = bo->bdev->driver;
-	struct ttm_bo_device *bdev = bo->bdev;
  	void *sync_obj;
  	int ret = 0;
  
@@ -1538,53 +1523,33 @@ int ttm_bo_wait(struct ttm_buffer_object *bo,
  	if (likely(bo->sync_obj == NULL))
  		return 0;
  
-	while (bo->sync_obj) {
-
+	if (bo->sync_obj) {
  		if (driver->sync_obj_signaled(bo->sync_obj)) {
-			void *tmp_obj = bo->sync_obj;
-			bo->sync_obj = NULL;
+			driver->sync_obj_unref(&bo->sync_obj);
  			clear_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
-			spin_unlock(&bdev->fence_lock);
-			driver->sync_obj_unref(&tmp_obj);
-			spin_lock(&bdev->fence_lock);
-			continue;
+			return 0;
  		}
  
  		if (no_wait)
  			return -EBUSY;
  
  		sync_obj = driver->sync_obj_ref(bo->sync_obj);
-		spin_unlock(&bdev->fence_lock);
  		ret = driver->sync_obj_wait(sync_obj,
  					    lazy, interruptible);
-		if (unlikely(ret != 0)) {
-			driver->sync_obj_unref(&sync_obj);
-			spin_lock(&bdev->fence_lock);
-			return ret;
-		}
-		spin_lock(&bdev->fence_lock);
-		if (likely(bo->sync_obj == sync_obj)) {
-			void *tmp_obj = bo->sync_obj;
-			bo->sync_obj = NULL;
+
+		if (likely(ret == 0)) {
  			clear_bit(TTM_BO_PRIV_FLAG_MOVING,
  				  &bo->priv_flags);
-			spin_unlock(&bdev->fence_lock);
-			driver->sync_obj_unref(&sync_obj);
-			driver->sync_obj_unref(&tmp_obj);
-			spin_lock(&bdev->fence_lock);
-		} else {
-			spin_unlock(&bdev->fence_lock);
-			driver->sync_obj_unref(&sync_obj);
-			spin_lock(&bdev->fence_lock);
+			driver->sync_obj_unref(&bo->sync_obj);
  		}
+		driver->sync_obj_unref(&sync_obj);
  	}
-	return 0;
+	return ret;
  }
  EXPORT_SYMBOL(ttm_bo_wait);
  
  int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
  {
-	struct ttm_bo_device *bdev = bo->bdev;
  	int ret = 0;
  
  	/*
@@ -1594,9 +1559,7 @@ int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
  	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
  	if (unlikely(ret != 0))
  		return ret;
-	spin_lock(&bdev->fence_lock);
  	ret = ttm_bo_wait(bo, false, true, no_wait);
-	spin_unlock(&bdev->fence_lock);
  	if (likely(ret == 0))
  		atomic_inc(&bo->cpu_writers);
  	ttm_bo_unreserve(bo);
@@ -1653,9 +1616,7 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
  	 * Wait for GPU, then move to system cached.
  	 */
  
-	spin_lock(&bo->bdev->fence_lock);
  	ret = ttm_bo_wait(bo, false, false, false);
-	spin_unlock(&bo->bdev->fence_lock);
  
  	if (unlikely(ret != 0))
  		goto out;
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 1df856f78568..23db594e55c0 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -466,12 +466,10 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
  	drm_vma_node_reset(&fbo->vma_node);
  	atomic_set(&fbo->cpu_writers, 0);
  
-	spin_lock(&bdev->fence_lock);
  	if (bo->sync_obj)
  		fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
  	else
  		fbo->sync_obj = NULL;
-	spin_unlock(&bdev->fence_lock);
  	kref_init(&fbo->list_kref);
  	kref_init(&fbo->kref);
  	fbo->destroy = &ttm_transfered_destroy;
@@ -657,7 +655,6 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
  	struct ttm_buffer_object *ghost_obj;
  	void *tmp_obj = NULL;
  
-	spin_lock(&bdev->fence_lock);
  	if (bo->sync_obj) {
  		tmp_obj = bo->sync_obj;
  		bo->sync_obj = NULL;
@@ -665,7 +662,6 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
  	bo->sync_obj = driver->sync_obj_ref(sync_obj);
  	if (evict) {
  		ret = ttm_bo_wait(bo, false, false, false);
-		spin_unlock(&bdev->fence_lock);
  		if (tmp_obj)
  			driver->sync_obj_unref(&tmp_obj);
  		if (ret)
@@ -688,7 +684,6 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
  		 */
  
  		set_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
-		spin_unlock(&bdev->fence_lock);
  		if (tmp_obj)
  			driver->sync_obj_unref(&tmp_obj);
  
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 801231c9ae48..6bf22391999d 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -45,10 +45,8 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
  				struct vm_area_struct *vma,
  				struct vm_fault *vmf)
  {
-	struct ttm_bo_device *bdev = bo->bdev;
  	int ret = 0;
  
-	spin_lock(&bdev->fence_lock);
  	if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
  		goto out_unlock;
  
@@ -82,7 +80,6 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
  			VM_FAULT_NOPAGE;
  
  out_unlock:
-	spin_unlock(&bdev->fence_lock);
  	return ret;
  }
  
diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
index ec36206da95a..bedb3fba4493 100644
--- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c
+++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
@@ -181,7 +181,6 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
  	glob = bo->glob;
  
  	spin_lock(&glob->lru_lock);
-	spin_lock(&bdev->fence_lock);
  
  	list_for_each_entry(entry, list, head) {
  		bo = entry->bo;
@@ -190,7 +189,6 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
  		ttm_bo_add_to_lru(bo);
  		ww_mutex_unlock(&bo->resv->lock);
  	}
-	spin_unlock(&bdev->fence_lock);
  	spin_unlock(&glob->lru_lock);
  	if (ticket)
  		ww_acquire_fini(ticket);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
index 6327cfc36805..4a36bb1dc525 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
@@ -829,11 +829,7 @@ static void vmw_move_notify(struct ttm_buffer_object *bo,
   */
  static void vmw_swap_notify(struct ttm_buffer_object *bo)
  {
-	struct ttm_bo_device *bdev = bo->bdev;
-
-	spin_lock(&bdev->fence_lock);
  	ttm_bo_wait(bo, false, false, false);
-	spin_unlock(&bdev->fence_lock);
  }
  
  
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index 9bfde71a2232..fdc76323c534 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -554,12 +554,13 @@ static int vmw_user_dmabuf_synccpu_grab(struct vmw_user_dma_buffer *user_bo,
  	int ret;
  
  	if (flags & drm_vmw_synccpu_allow_cs) {
-		struct ttm_bo_device *bdev = bo->bdev;
+		int try = !!(flags & drm_vmw_synccpu_dontblock);
  
-		spin_lock(&bdev->fence_lock);
-		ret = ttm_bo_wait(bo, false, true,
-				  !!(flags & drm_vmw_synccpu_dontblock));
-		spin_unlock(&bdev->fence_lock);
+		ret = ttm_bo_reserve(bo, false, try, false, NULL);
+		if (!ret) {
+			ret = ttm_bo_wait(bo, false, true, try);
+			ttm_bo_unreserve(bo);
+		}
  		return ret;
  	}
  
@@ -1419,12 +1420,10 @@ void vmw_fence_single_bo(struct ttm_buffer_object *bo,
  	else
  		driver->sync_obj_ref(fence);
  
-	spin_lock(&bdev->fence_lock);
  
  	old_fence_obj = bo->sync_obj;
  	bo->sync_obj = fence;
  
-	spin_unlock(&bdev->fence_lock);
  
  	if (old_fence_obj)
  		vmw_fence_obj_unreference(&old_fence_obj);
@@ -1465,7 +1464,6 @@ void vmw_resource_move_notify(struct ttm_buffer_object *bo,
  
  	if (mem->mem_type != VMW_PL_MOB) {
  		struct vmw_resource *res, *n;
-		struct ttm_bo_device *bdev = bo->bdev;
  		struct ttm_validate_buffer val_buf;
  
  		val_buf.bo = bo;
@@ -1481,9 +1479,7 @@ void vmw_resource_move_notify(struct ttm_buffer_object *bo,
  			list_del_init(&res->mob_head);
  		}
  
-		spin_lock(&bdev->fence_lock);
  		(void) ttm_bo_wait(bo, false, false, false);
-		spin_unlock(&bdev->fence_lock);
  	}
  }
  
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index ee127ec33c60..f34d59b67218 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -227,10 +227,7 @@ struct ttm_buffer_object {
  	struct list_head io_reserve_lru;
  
  	/**
-	 * Members protected by struct buffer_object_device::fence_lock
-	 * In addition, setting sync_obj to anything else
-	 * than NULL requires bo::reserved to be held. This allows for
-	 * checking NULL while reserved but not holding the mentioned lock.
+	 * Members protected by a bo reservation.
  	 */
  
  	void *sync_obj;
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 32d34ebf0706..e7045bc12d3b 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -518,8 +518,6 @@ struct ttm_bo_global {
   *
   * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
   * @man: An array of mem_type_managers.
- * @fence_lock: Protects the synchronizing members on *all* bos belonging
- * to this device.
   * @vma_manager: Address space manager
   * lru_lock: Spinlock that protects the buffer+device lru lists and
   * ddestroy lists.
@@ -539,7 +537,6 @@ struct ttm_bo_device {
  	struct ttm_bo_global *glob;
  	struct ttm_bo_driver *driver;
  	struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
-	spinlock_t fence_lock;
  
  	/*
  	 * Protected by internal locks.
-- 
1.8.5.2