ttm: Make parts of a struct ttm_bo_device global.

Common resources, like memory accounting and swap lists should be
global and not per device. Introduce a struct ttm_bo_global to
accomodate this, and register it with sysfs. Add a small sysfs interface
to return the number of active buffer objects.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>

drivers/gpu/drm/radeon/radeon_object.h

@@ -37,6 +37,7 @@
  * TTM.
  */
 struct radeon_mman {
+	struct ttm_bo_global_ref        bo_global_ref;
 	struct ttm_global_reference	mem_global_ref;
 	bool				mem_global_referenced;
 	struct ttm_bo_device		bdev;

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -77,9 +77,25 @@ static int radeon_ttm_global_init(struct radeon_device *rdev)
 	global_ref->release = &radeon_ttm_mem_global_release;
 	r = ttm_global_item_ref(global_ref);
 	if (r != 0) {
-		DRM_ERROR("Failed referencing a global TTM memory object.\n");
+		DRM_ERROR("Failed setting up TTM memory accounting "
+			  "subsystem.\n");
 		return r;
 	}
+
+	rdev->mman.bo_global_ref.mem_glob =
+		rdev->mman.mem_global_ref.object;
+	global_ref = &rdev->mman.bo_global_ref.ref;
+	global_ref->global_type = TTM_GLOBAL_TTM_BO;
+	global_ref->size = sizeof(struct ttm_mem_global);
+	global_ref->init = &ttm_bo_global_init;
+	global_ref->release = &ttm_bo_global_release;
+	r = ttm_global_item_ref(global_ref);
+	if (r != 0) {
+		DRM_ERROR("Failed setting up TTM BO subsystem.\n");
+		ttm_global_item_unref(&rdev->mman.mem_global_ref);
+		return r;
+	}
+
 	rdev->mman.mem_global_referenced = true;
 	return 0;
 }
@@ -87,6 +103,7 @@ static int radeon_ttm_global_init(struct radeon_device *rdev)
 static void radeon_ttm_global_fini(struct radeon_device *rdev)
 {
 	if (rdev->mman.mem_global_referenced) {
+		ttm_global_item_unref(&rdev->mman.bo_global_ref.ref);
 		ttm_global_item_unref(&rdev->mman.mem_global_ref);
 		rdev->mman.mem_global_referenced = false;
 	}
@@ -286,9 +303,11 @@ static int radeon_move_vram_ram(struct ttm_buffer_object *bo,
 	r = ttm_bo_move_ttm(bo, true, no_wait, new_mem);
 out_cleanup:
 	if (tmp_mem.mm_node) {
-		spin_lock(&rdev->mman.bdev.lru_lock);
+		struct ttm_bo_global *glob = rdev->mman.bdev.glob;
+
+		spin_lock(&glob->lru_lock);
 		drm_mm_put_block(tmp_mem.mm_node);
-		spin_unlock(&rdev->mman.bdev.lru_lock);
+		spin_unlock(&glob->lru_lock);
 		return r;
 	}
 	return r;
@@ -323,9 +342,11 @@ static int radeon_move_ram_vram(struct ttm_buffer_object *bo,
 	}
 out_cleanup:
 	if (tmp_mem.mm_node) {
-		spin_lock(&rdev->mman.bdev.lru_lock);
+		struct ttm_bo_global *glob = rdev->mman.bdev.glob;
+
+		spin_lock(&glob->lru_lock);
 		drm_mm_put_block(tmp_mem.mm_node);
-		spin_unlock(&rdev->mman.bdev.lru_lock);
+		spin_unlock(&glob->lru_lock);
 		return r;
 	}
 	return r;
@@ -441,7 +462,7 @@ int radeon_ttm_init(struct radeon_device *rdev)
 	}
 	/* No others user of address space so set it to 0 */
 	r = ttm_bo_device_init(&rdev->mman.bdev,
-			       rdev->mman.mem_global_ref.object,
+			       rdev->mman.bo_global_ref.ref.object,
 			       &radeon_bo_driver, DRM_FILE_PAGE_OFFSET);
 	if (r) {
 		DRM_ERROR("failed initializing buffer object driver(%d).\n", r);

drivers/gpu/drm/ttm/ttm_bo.c

@@ -45,6 +45,39 @@
 static int ttm_bo_setup_vm(struct ttm_buffer_object *bo);
 static void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
 static int ttm_bo_swapout(struct ttm_mem_shrink *shrink);
+static void ttm_bo_global_kobj_release(struct kobject *kobj);
+
+static struct attribute ttm_bo_count = {
+	.name = "bo_count",
+	.mode = S_IRUGO
+};
+
+static ssize_t ttm_bo_global_show(struct kobject *kobj,
+				  struct attribute *attr,
+				  char *buffer)
+{
+	struct ttm_bo_global *glob =
+		container_of(kobj, struct ttm_bo_global, kobj);
+
+	return snprintf(buffer, PAGE_SIZE, "%lu\n",
+			(unsigned long) atomic_read(&glob->bo_count));
+}
+
+static struct attribute *ttm_bo_global_attrs[] = {
+	&ttm_bo_count,
+	NULL
+};
+
+static struct sysfs_ops ttm_bo_global_ops = {
+	.show = &ttm_bo_global_show
+};
+
+static struct kobj_type ttm_bo_glob_kobj_type  = {
+	.release = &ttm_bo_global_kobj_release,
+	.sysfs_ops = &ttm_bo_global_ops,
+	.default_attrs = ttm_bo_global_attrs
+};
+
 
 static inline uint32_t ttm_bo_type_flags(unsigned type)
 {
@@ -67,10 +100,11 @@ static void ttm_bo_release_list(struct kref *list_kref)
 
 	if (bo->ttm)
 		ttm_tt_destroy(bo->ttm);
+	atomic_dec(&bo->glob->bo_count);
 	if (bo->destroy)
 		bo->destroy(bo);
 	else {
-		ttm_mem_global_free(bdev->mem_glob, bo->acc_size);
+		ttm_mem_global_free(bdev->glob->mem_glob, bo->acc_size);
 		kfree(bo);
 	}
 }
@@ -107,7 +141,7 @@ static void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
 		kref_get(&bo->list_kref);
 
 		if (bo->ttm != NULL) {
-			list_add_tail(&bo->swap, &bdev->swap_lru);
+			list_add_tail(&bo->swap, &bo->glob->swap_lru);
 			kref_get(&bo->list_kref);
 		}
 	}
@@ -142,7 +176,7 @@ int ttm_bo_reserve_locked(struct ttm_buffer_object *bo,
 			  bool interruptible,
 			  bool no_wait, bool use_sequence, uint32_t sequence)
 {
-	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 	int ret;
 
 	while (unlikely(atomic_cmpxchg(&bo->reserved, 0, 1) != 0)) {
@@ -154,9 +188,9 @@ int ttm_bo_reserve_locked(struct ttm_buffer_object *bo,
 		if (no_wait)
 			return -EBUSY;
 
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 		ret = ttm_bo_wait_unreserved(bo, interruptible);
-		spin_lock(&bdev->lru_lock);
+		spin_lock(&glob->lru_lock);
 
 		if (unlikely(ret))
 			return ret;
@@ -182,16 +216,16 @@ int ttm_bo_reserve(struct ttm_buffer_object *bo,
 		   bool interruptible,
 		   bool no_wait, bool use_sequence, uint32_t sequence)
 {
-	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 	int put_count = 0;
 	int ret;
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	ret = ttm_bo_reserve_locked(bo, interruptible, no_wait, use_sequence,
 				    sequence);
 	if (likely(ret == 0))
 		put_count = ttm_bo_del_from_lru(bo);
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 
 	while (put_count--)
 		kref_put(&bo->list_kref, ttm_bo_ref_bug);
@@ -201,13 +235,13 @@ int ttm_bo_reserve(struct ttm_buffer_object *bo,
 
 void ttm_bo_unreserve(struct ttm_buffer_object *bo)
 {
-	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	ttm_bo_add_to_lru(bo);
 	atomic_set(&bo->reserved, 0);
 	wake_up_all(&bo->event_queue);
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 }
 EXPORT_SYMBOL(ttm_bo_unreserve);
 
@@ -218,6 +252,7 @@ EXPORT_SYMBOL(ttm_bo_unreserve);
 static int ttm_bo_add_ttm(struct ttm_buffer_object *bo, bool zero_alloc)
 {
 	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 	int ret = 0;
 	uint32_t page_flags = 0;
 
@@ -230,14 +265,14 @@ static int ttm_bo_add_ttm(struct ttm_buffer_object *bo, bool zero_alloc)
 			page_flags |= TTM_PAGE_FLAG_ZERO_ALLOC;
 	case ttm_bo_type_kernel:
 		bo->ttm = ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
-					page_flags, bdev->dummy_read_page);
+					page_flags, glob->dummy_read_page);
 		if (unlikely(bo->ttm == NULL))
 			ret = -ENOMEM;
 		break;
 	case ttm_bo_type_user:
 		bo->ttm = ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
 					page_flags | TTM_PAGE_FLAG_USER,
-					bdev->dummy_read_page);
+					glob->dummy_read_page);
 		if (unlikely(bo->ttm == NULL))
 			ret = -ENOMEM;
 		break;
@@ -355,6 +390,7 @@ out_err:
 static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 {
 	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 	struct ttm_bo_driver *driver = bdev->driver;
 	int ret;
 
@@ -366,7 +402,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 
 		spin_unlock(&bo->lock);
 
-		spin_lock(&bdev->lru_lock);
+		spin_lock(&glob->lru_lock);
 		ret = ttm_bo_reserve_locked(bo, false, false, false, 0);
 		BUG_ON(ret);
 		if (bo->ttm)
@@ -381,7 +417,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 			bo->mem.mm_node = NULL;
 		}
 		put_count = ttm_bo_del_from_lru(bo);
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 
 		atomic_set(&bo->reserved, 0);
 
@@ -391,14 +427,14 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 		return 0;
 	}
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	if (list_empty(&bo->ddestroy)) {
 		void *sync_obj = bo->sync_obj;
 		void *sync_obj_arg = bo->sync_obj_arg;
 
 		kref_get(&bo->list_kref);
 		list_add_tail(&bo->ddestroy, &bdev->ddestroy);
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 		spin_unlock(&bo->lock);
 
 		if (sync_obj)
@@ -408,7 +444,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 		ret = 0;
 
 	} else {
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 		spin_unlock(&bo->lock);
 		ret = -EBUSY;
 	}
@@ -423,11 +459,12 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 
 static int ttm_bo_delayed_delete(struct ttm_bo_device *bdev, bool remove_all)
 {
+	struct ttm_bo_global *glob = bdev->glob;
 	struct ttm_buffer_object *entry, *nentry;
 	struct list_head *list, *next;
 	int ret;
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	list_for_each_safe(list, next, &bdev->ddestroy) {
 		entry = list_entry(list, struct ttm_buffer_object, ddestroy);
 		nentry = NULL;
@@ -444,16 +481,16 @@ static int ttm_bo_delayed_delete(struct ttm_bo_device *bdev, bool remove_all)
 		}
 		kref_get(&entry->list_kref);
 
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 		ret = ttm_bo_cleanup_refs(entry, remove_all);
 		kref_put(&entry->list_kref, ttm_bo_release_list);
 
-		spin_lock(&bdev->lru_lock);
+		spin_lock(&glob->lru_lock);
 		if (nentry) {
 			bool next_onlist = !list_empty(next);
-			spin_unlock(&bdev->lru_lock);
+			spin_unlock(&glob->lru_lock);
 			kref_put(&nentry->list_kref, ttm_bo_release_list);
-			spin_lock(&bdev->lru_lock);
+			spin_lock(&glob->lru_lock);
 			/*
 			 * Someone might have raced us and removed the
 			 * next entry from the list. We don't bother restarting
@@ -467,7 +504,7 @@ static int ttm_bo_delayed_delete(struct ttm_bo_device *bdev, bool remove_all)
 			break;
 	}
 	ret = !list_empty(&bdev->ddestroy);
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 
 	return ret;
 }
@@ -517,6 +554,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, unsigned mem_type,
 {
 	int ret = 0;
 	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 	struct ttm_mem_reg evict_mem;
 	uint32_t proposed_placement;
 
@@ -565,12 +603,12 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, unsigned mem_type,
 		goto out;
 	}
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	if (evict_mem.mm_node) {
 		drm_mm_put_block(evict_mem.mm_node);
 		evict_mem.mm_node = NULL;
 	}
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 	bo->evicted = true;
 out:
 	return ret;
@@ -585,6 +623,7 @@ static int ttm_bo_mem_force_space(struct ttm_bo_device *bdev,
 				  uint32_t mem_type,
 				  bool interruptible, bool no_wait)
 {
+	struct ttm_bo_global *glob = bdev->glob;
 	struct drm_mm_node *node;
 	struct ttm_buffer_object *entry;
 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
@@ -598,7 +637,7 @@ retry_pre_get:
 	if (unlikely(ret != 0))
 		return ret;
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	do {
 		node = drm_mm_search_free(&man->manager, num_pages,
 					  mem->page_alignment, 1);
@@ -619,7 +658,7 @@ retry_pre_get:
 		if (likely(ret == 0))
 			put_count = ttm_bo_del_from_lru(entry);
 
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 
 		if (unlikely(ret != 0))
 			return ret;
@@ -635,21 +674,21 @@ retry_pre_get:
 		if (ret)
 			return ret;
 
-		spin_lock(&bdev->lru_lock);
+		spin_lock(&glob->lru_lock);
 	} while (1);
 
 	if (!node) {
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 		return -ENOMEM;
 	}
 
 	node = drm_mm_get_block_atomic(node, num_pages, mem->page_alignment);
 	if (unlikely(!node)) {
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 		goto retry_pre_get;
 	}
 
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 	mem->mm_node = node;
 	mem->mem_type = mem_type;
 	return 0;
@@ -697,6 +736,7 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 		     bool interruptible, bool no_wait)
 {
 	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 	struct ttm_mem_type_manager *man;
 
 	uint32_t num_prios = bdev->driver->num_mem_type_prio;
@@ -733,20 +773,20 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 				if (unlikely(ret))
 					return ret;
 
-				spin_lock(&bdev->lru_lock);
+				spin_lock(&glob->lru_lock);
 				node = drm_mm_search_free(&man->manager,
 							  mem->num_pages,
 							  mem->page_alignment,
 							  1);
 				if (unlikely(!node)) {
-					spin_unlock(&bdev->lru_lock);
+					spin_unlock(&glob->lru_lock);
 					break;
 				}
 				node = drm_mm_get_block_atomic(node,
 							       mem->num_pages,
 							       mem->
 							       page_alignment);
-				spin_unlock(&bdev->lru_lock);
+				spin_unlock(&glob->lru_lock);
 			} while (!node);
 		}
 		if (node)
@@ -816,7 +856,7 @@ int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 		       uint32_t proposed_placement,
 		       bool interruptible, bool no_wait)
 {
-	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
 	int ret = 0;
 	struct ttm_mem_reg mem;
 
@@ -852,9 +892,9 @@ int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 
 out_unlock:
 	if (ret && mem.mm_node) {
-		spin_lock(&bdev->lru_lock);
+		spin_lock(&glob->lru_lock);
 		drm_mm_put_block(mem.mm_node);
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 	}
 	return ret;
 }
@@ -990,6 +1030,7 @@ int ttm_buffer_object_init(struct ttm_bo_device *bdev,
 	INIT_LIST_HEAD(&bo->ddestroy);
 	INIT_LIST_HEAD(&bo->swap);
 	bo->bdev = bdev;
+	bo->glob = bdev->glob;
 	bo->type = type;
 	bo->num_pages = num_pages;
 	bo->mem.mem_type = TTM_PL_SYSTEM;
@@ -1002,6 +1043,7 @@ int ttm_buffer_object_init(struct ttm_bo_device *bdev,
 	bo->seq_valid = false;
 	bo->persistant_swap_storage = persistant_swap_storage;
 	bo->acc_size = acc_size;
+	atomic_inc(&bo->glob->bo_count);
 
 	ret = ttm_bo_check_placement(bo, flags, 0ULL);
 	if (unlikely(ret != 0))
@@ -1040,13 +1082,13 @@ out_err:
 }
 EXPORT_SYMBOL(ttm_buffer_object_init);
 
-static inline size_t ttm_bo_size(struct ttm_bo_device *bdev,
+static inline size_t ttm_bo_size(struct ttm_bo_global *glob,
 				 unsigned long num_pages)
 {
 	size_t page_array_size = (num_pages * sizeof(void *) + PAGE_SIZE - 1) &
 	    PAGE_MASK;
 
-	return bdev->ttm_bo_size + 2 * page_array_size;
+	return glob->ttm_bo_size + 2 * page_array_size;
 }
 
 int ttm_buffer_object_create(struct ttm_bo_device *bdev,
@@ -1061,10 +1103,10 @@ int ttm_buffer_object_create(struct ttm_bo_device *bdev,
 {
 	struct ttm_buffer_object *bo;
 	int ret;
-	struct ttm_mem_global *mem_glob = bdev->mem_glob;
+	struct ttm_mem_global *mem_glob = bdev->glob->mem_glob;
 
 	size_t acc_size =
-	    ttm_bo_size(bdev, (size + PAGE_SIZE - 1) >> PAGE_SHIFT);
+	    ttm_bo_size(bdev->glob, (size + PAGE_SIZE - 1) >> PAGE_SHIFT);
 	ret = ttm_mem_global_alloc(mem_glob, acc_size, false, false);
 	if (unlikely(ret != 0))
 		return ret;
@@ -1118,6 +1160,7 @@ static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
 				   struct list_head *head,
 				   unsigned mem_type, bool allow_errors)
 {
+	struct ttm_bo_global *glob = bdev->glob;
 	struct ttm_buffer_object *entry;
 	int ret;
 	int put_count;
@@ -1126,30 +1169,31 @@ static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
 	 * Can't use standard list traversal since we're unlocking.
 	 */
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 
 	while (!list_empty(head)) {
 		entry = list_first_entry(head, struct ttm_buffer_object, lru);
 		kref_get(&entry->list_kref);
 		ret = ttm_bo_reserve_locked(entry, false, false, false, 0);
 		put_count = ttm_bo_del_from_lru(entry);
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 		while (put_count--)
 			kref_put(&entry->list_kref, ttm_bo_ref_bug);
 		BUG_ON(ret);
 		ret = ttm_bo_leave_list(entry, mem_type, allow_errors);
 		ttm_bo_unreserve(entry);
 		kref_put(&entry->list_kref, ttm_bo_release_list);
-		spin_lock(&bdev->lru_lock);
+		spin_lock(&glob->lru_lock);
 	}
 
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 
 	return 0;
 }
 
 int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type)
 {
+	struct ttm_bo_global *glob = bdev->glob;
 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
 	int ret = -EINVAL;
 
@@ -1171,13 +1215,13 @@ int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type)
 	if (mem_type > 0) {
 		ttm_bo_force_list_clean(bdev, &man->lru, mem_type, false);
 
-		spin_lock(&bdev->lru_lock);
+		spin_lock(&glob->lru_lock);
 		if (drm_mm_clean(&man->manager))
 			drm_mm_takedown(&man->manager);
 		else
 			ret = -EBUSY;
 
-		spin_unlock(&bdev->lru_lock);
+		spin_unlock(&glob->lru_lock);
 	}
 
 	return ret;
@@ -1251,11 +1295,83 @@ int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
 }
 EXPORT_SYMBOL(ttm_bo_init_mm);
 
+static void ttm_bo_global_kobj_release(struct kobject *kobj)
+{
+	struct ttm_bo_global *glob =
+		container_of(kobj, struct ttm_bo_global, kobj);
+
+	printk(KERN_INFO TTM_PFX "Freeing bo global.\n");
+	ttm_mem_unregister_shrink(glob->mem_glob, &glob->shrink);
+	__free_page(glob->dummy_read_page);
+	kfree(glob);
+}
+
+void ttm_bo_global_release(struct ttm_global_reference *ref)
+{
+	struct ttm_bo_global *glob = ref->object;
+
+	kobject_del(&glob->kobj);
+	kobject_put(&glob->kobj);
+}
+EXPORT_SYMBOL(ttm_bo_global_release);
+
+int ttm_bo_global_init(struct ttm_global_reference *ref)
+{
+	struct ttm_bo_global_ref *bo_ref =
+		container_of(ref, struct ttm_bo_global_ref, ref);
+	struct ttm_bo_global *glob = ref->object;
+	int ret;
+
+	mutex_init(&glob->device_list_mutex);
+	spin_lock_init(&glob->lru_lock);
+	glob->mem_glob = bo_ref->mem_glob;
+	glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
+
+	if (unlikely(glob->dummy_read_page == NULL)) {
+		ret = -ENOMEM;
+		goto out_no_drp;
+	}
+
+	INIT_LIST_HEAD(&glob->swap_lru);
+	INIT_LIST_HEAD(&glob->device_list);
+
+	ttm_mem_init_shrink(&glob->shrink, ttm_bo_swapout);
+	ret = ttm_mem_register_shrink(glob->mem_glob, &glob->shrink);
+	if (unlikely(ret != 0)) {
+		printk(KERN_ERR TTM_PFX
+		       "Could not register buffer object swapout.\n");
+		goto out_no_shrink;
+	}
+
+	glob->ttm_bo_extra_size =
+		ttm_round_pot(sizeof(struct ttm_tt)) +
+		ttm_round_pot(sizeof(struct ttm_backend));
+
+	glob->ttm_bo_size = glob->ttm_bo_extra_size +
+		ttm_round_pot(sizeof(struct ttm_buffer_object));
+
+	atomic_set(&glob->bo_count, 0);
+
+	kobject_init(&glob->kobj, &ttm_bo_glob_kobj_type);
+	ret = kobject_add(&glob->kobj, ttm_get_kobj(), "buffer_objects");
+	if (unlikely(ret != 0))
+		kobject_put(&glob->kobj);
+	return ret;
+out_no_shrink:
+	__free_page(glob->dummy_read_page);
+out_no_drp:
+	kfree(glob);
+	return ret;
+}
+EXPORT_SYMBOL(ttm_bo_global_init);
+
+
 int ttm_bo_device_release(struct ttm_bo_device *bdev)
 {
 	int ret = 0;
 	unsigned i = TTM_NUM_MEM_TYPES;
 	struct ttm_mem_type_manager *man;
+	struct ttm_bo_global *glob = bdev->glob;
 
 	while (i--) {
 		man = &bdev->man[i];
@@ -1271,98 +1387,74 @@ int ttm_bo_device_release(struct ttm_bo_device *bdev)
 		}
 	}
 
+	mutex_lock(&glob->device_list_mutex);
+	list_del(&bdev->device_list);
+	mutex_unlock(&glob->device_list_mutex);
+
 	if (!cancel_delayed_work(&bdev->wq))
 		flush_scheduled_work();
 
 	while (ttm_bo_delayed_delete(bdev, true))
 		;
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	if (list_empty(&bdev->ddestroy))
 		TTM_DEBUG("Delayed destroy list was clean\n");
 
 	if (list_empty(&bdev->man[0].lru))
 		TTM_DEBUG("Swap list was clean\n");
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 
-	ttm_mem_unregister_shrink(bdev->mem_glob, &bdev->shrink);
 	BUG_ON(!drm_mm_clean(&bdev->addr_space_mm));
 	write_lock(&bdev->vm_lock);
 	drm_mm_takedown(&bdev->addr_space_mm);
 	write_unlock(&bdev->vm_lock);
 
-	__free_page(bdev->dummy_read_page);
 	return ret;
 }
 EXPORT_SYMBOL(ttm_bo_device_release);
 
-/*
- * This function is intended to be called on drm driver load.
- * If you decide to call it from firstopen, you must protect the call
- * from a potentially racing ttm_bo_driver_finish in lastclose.
- * (This may happen on X server restart).
- */
-
 int ttm_bo_device_init(struct ttm_bo_device *bdev,
-		       struct ttm_mem_global *mem_glob,
-		       struct ttm_bo_driver *driver, uint64_t file_page_offset)
+		       struct ttm_bo_global *glob,
+		       struct ttm_bo_driver *driver,
+		       uint64_t file_page_offset)
 {
 	int ret = -EINVAL;
 
-	bdev->dummy_read_page = NULL;
 	rwlock_init(&bdev->vm_lock);
-	spin_lock_init(&bdev->lru_lock);
+	spin_lock_init(&glob->lru_lock);
 
 	bdev->driver = driver;
-	bdev->mem_glob = mem_glob;
 
 	memset(bdev->man, 0, sizeof(bdev->man));
 
-	bdev->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
-	if (unlikely(bdev->dummy_read_page == NULL)) {
-		ret = -ENOMEM;
-		goto out_err0;
-	}
-
 	/*
 	 * Initialize the system memory buffer type.
 	 * Other types need to be driver / IOCTL initialized.
 	 */
 	ret = ttm_bo_init_mm(bdev, TTM_PL_SYSTEM, 0, 0);
 	if (unlikely(ret != 0))
-		goto out_err1;
+		goto out_no_sys;
 
 	bdev->addr_space_rb = RB_ROOT;
 	ret = drm_mm_init(&bdev->addr_space_mm, file_page_offset, 0x10000000);
 	if (unlikely(ret != 0))
-		goto out_err2;
+		goto out_no_addr_mm;
 
 	INIT_DELAYED_WORK(&bdev->wq, ttm_bo_delayed_workqueue);
 	bdev->nice_mode = true;
 	INIT_LIST_HEAD(&bdev->ddestroy);
-	INIT_LIST_HEAD(&bdev->swap_lru);
 	bdev->dev_mapping = NULL;
-	ttm_mem_init_shrink(&bdev->shrink, ttm_bo_swapout);
-	ret = ttm_mem_register_shrink(mem_glob, &bdev->shrink);
-	if (unlikely(ret != 0)) {
-		printk(KERN_ERR TTM_PFX
-		       "Could not register buffer object swapout.\n");
-		goto out_err2;
-	}
+	bdev->glob = glob;
 
-	bdev->ttm_bo_extra_size =
-		ttm_round_pot(sizeof(struct ttm_tt)) +
-		ttm_round_pot(sizeof(struct ttm_backend));
-
-	bdev->ttm_bo_size = bdev->ttm_bo_extra_size +
-		ttm_round_pot(sizeof(struct ttm_buffer_object));
+	mutex_lock(&glob->device_list_mutex);
+	list_add_tail(&bdev->device_list, &glob->device_list);
+	mutex_unlock(&glob->device_list_mutex);
 
 	return 0;
-out_err2:
+out_no_addr_mm:
 	ttm_bo_clean_mm(bdev, 0);
-out_err1:
-	__free_page(bdev->dummy_read_page);
-out_err0:
+out_no_sys:
 	return ret;
 }
 EXPORT_SYMBOL(ttm_bo_device_init);
@@ -1607,21 +1699,21 @@ void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo)
 
 static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
 {
-	struct ttm_bo_device *bdev =
-	    container_of(shrink, struct ttm_bo_device, shrink);
+	struct ttm_bo_global *glob =
+	    container_of(shrink, struct ttm_bo_global, shrink);
 	struct ttm_buffer_object *bo;
 	int ret = -EBUSY;
 	int put_count;
 	uint32_t swap_placement = (TTM_PL_FLAG_CACHED | TTM_PL_FLAG_SYSTEM);
 
-	spin_lock(&bdev->lru_lock);
+	spin_lock(&glob->lru_lock);
 	while (ret == -EBUSY) {
-		if (unlikely(list_empty(&bdev->swap_lru))) {
-			spin_unlock(&bdev->lru_lock);
+		if (unlikely(list_empty(&glob->swap_lru))) {
+			spin_unlock(&glob->lru_lock);
 			return -EBUSY;
 		}
 
-		bo = list_first_entry(&bdev->swap_lru,
+		bo = list_first_entry(&glob->swap_lru,
 				      struct ttm_buffer_object, swap);
 		kref_get(&bo->list_kref);
 
@@ -1633,16 +1725,16 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
 
 		ret = ttm_bo_reserve_locked(bo, false, true, false, 0);
 		if (unlikely(ret == -EBUSY)) {
-			spin_unlock(&bdev->lru_lock);
+			spin_unlock(&glob->lru_lock);
 			ttm_bo_wait_unreserved(bo, false);
 			kref_put(&bo->list_kref, ttm_bo_release_list);
-			spin_lock(&bdev->lru_lock);
+			spin_lock(&glob->lru_lock);
 		}
 	}
 
 	BUG_ON(ret != 0);
 	put_count = ttm_bo_del_from_lru(bo);
-	spin_unlock(&bdev->lru_lock);
+	spin_unlock(&glob->lru_lock);
 
 	while (put_count--)
 		kref_put(&bo->list_kref, ttm_bo_ref_bug);
@@ -1696,6 +1788,6 @@ out:
 
 void ttm_bo_swapout_all(struct ttm_bo_device *bdev)
 {
-	while (ttm_bo_swapout(&bdev->shrink) == 0)
+	while (ttm_bo_swapout(&bdev->glob->shrink) == 0)
 		;
 }

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -41,9 +41,9 @@ void ttm_bo_free_old_node(struct ttm_buffer_object *bo)
 	struct ttm_mem_reg *old_mem = &bo->mem;
 
 	if (old_mem->mm_node) {
-		spin_lock(&bo->bdev->lru_lock);
+		spin_lock(&bo->glob->lru_lock);
 		drm_mm_put_block(old_mem->mm_node);
-		spin_unlock(&bo->bdev->lru_lock);
+		spin_unlock(&bo->glob->lru_lock);
 	}
 	old_mem->mm_node = NULL;
 }

drivers/gpu/drm/ttm/ttm_tt.c

@@ -166,7 +166,7 @@ static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
 			set_page_dirty_lock(page);
 
 		ttm->pages[i] = NULL;
-		ttm_mem_global_free(ttm->bdev->mem_glob, PAGE_SIZE);
+		ttm_mem_global_free(ttm->glob->mem_glob, PAGE_SIZE);
 		put_page(page);
 	}
 	ttm->state = tt_unpopulated;
@@ -177,8 +177,7 @@ static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
 static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
 {
 	struct page *p;
-	struct ttm_bo_device *bdev = ttm->bdev;
-	struct ttm_mem_global *mem_glob = bdev->mem_glob;
+	struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 	int ret;
 
 	while (NULL == (p = ttm->pages[index])) {
@@ -348,7 +347,7 @@ static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
 				printk(KERN_ERR TTM_PFX
 				       "Erroneous page count. "
 				       "Leaking pages.\n");
-			ttm_mem_global_free_page(ttm->bdev->mem_glob,
+			ttm_mem_global_free_page(ttm->glob->mem_glob,
 						 cur_page);
 			__free_page(cur_page);
 		}
@@ -394,7 +393,7 @@ int ttm_tt_set_user(struct ttm_tt *ttm,
 	struct mm_struct *mm = tsk->mm;
 	int ret;
 	int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
-	struct ttm_mem_global *mem_glob = ttm->bdev->mem_glob;
+	struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 
 	BUG_ON(num_pages != ttm->num_pages);
 	BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
@@ -439,8 +438,7 @@ struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 	if (!ttm)
 		return NULL;
 
-	ttm->bdev = bdev;
-
+	ttm->glob = bdev->glob;
 	ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	ttm->first_himem_page = ttm->num_pages;
 	ttm->last_lomem_page = -1;

include/drm/ttm/ttm_bo_api.h

@@ -155,6 +155,7 @@ struct ttm_buffer_object {
 	 * Members constant at init.
 	 */
 
+	struct ttm_bo_global *glob;
 	struct ttm_bo_device *bdev;
 	unsigned long buffer_start;
 	enum ttm_bo_type type;

include/drm/ttm/ttm_bo_driver.h

@@ -32,6 +32,7 @@
 
 #include "ttm/ttm_bo_api.h"
 #include "ttm/ttm_memory.h"
+#include "ttm/ttm_module.h"
 #include "drm_mm.h"
 #include "linux/workqueue.h"
 #include "linux/fs.h"
@@ -160,7 +161,7 @@ struct ttm_tt {
 	long last_lomem_page;
 	uint32_t page_flags;
 	unsigned long num_pages;
-	struct ttm_bo_device *bdev;
+	struct ttm_bo_global *glob;
 	struct ttm_backend *be;
 	struct task_struct *tsk;
 	unsigned long start;
@@ -355,24 +356,73 @@ struct ttm_bo_driver {
 	void *(*sync_obj_ref) (void *sync_obj);
 };
 
-#define TTM_NUM_MEM_TYPES 8
+/**
+ * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.
+ */
+
+struct ttm_bo_global_ref {
+	struct ttm_global_reference ref;
+	struct ttm_mem_global *mem_glob;
+};
 
-#define TTM_BO_PRIV_FLAG_MOVING  0	/* Buffer object is moving and needs
-					   idling before CPU mapping */
-#define TTM_BO_PRIV_FLAG_MAX 1
 /**
- * struct ttm_bo_device - Buffer object driver device-specific data.
+ * struct ttm_bo_global - Buffer object driver global data.
  *
  * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
- * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
- * @count: Current number of buffer object.
- * @pages: Current number of pinned pages.
  * @dummy_read_page: Pointer to a dummy page used for mapping requests
  * of unpopulated pages.
- * @shrink: A shrink callback object used for buffre object swap.
+ * @shrink: A shrink callback object used for buffer object swap.
  * @ttm_bo_extra_size: Extra size (sizeof(struct ttm_buffer_object) excluded)
  * used by a buffer object. This is excluding page arrays and backing pages.
  * @ttm_bo_size: This is @ttm_bo_extra_size + sizeof(struct ttm_buffer_object).
+ * @device_list_mutex: Mutex protecting the device list.
+ * This mutex is held while traversing the device list for pm options.
+ * @lru_lock: Spinlock protecting the bo subsystem lru lists.
+ * @device_list: List of buffer object devices.
+ * @swap_lru: Lru list of buffer objects used for swapping.
+ */
+
+struct ttm_bo_global {
+
+	/**
+	 * Constant after init.
+	 */
+
+	struct kobject kobj;
+	struct ttm_mem_global *mem_glob;
+	struct page *dummy_read_page;
+	struct ttm_mem_shrink shrink;
+	size_t ttm_bo_extra_size;
+	size_t ttm_bo_size;
+	struct mutex device_list_mutex;
+	spinlock_t lru_lock;
+
+	/**
+	 * Protected by device_list_mutex.
+	 */
+	struct list_head device_list;
+
+	/**
+	 * Protected by the lru_lock.
+	 */
+	struct list_head swap_lru;
+
+	/**
+	 * Internal protection.
+	 */
+	atomic_t bo_count;
+};
+
+
+#define TTM_NUM_MEM_TYPES 8
+
+#define TTM_BO_PRIV_FLAG_MOVING  0	/* Buffer object is moving and needs
+					   idling before CPU mapping */
+#define TTM_BO_PRIV_FLAG_MAX 1
+/**
+ * struct ttm_bo_device - Buffer object driver device-specific data.
+ *
+ * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
  * @man: An array of mem_type_managers.
  * @addr_space_mm: Range manager for the device address space.
  * lru_lock: Spinlock that protects the buffer+device lru lists and
@@ -390,32 +440,21 @@ struct ttm_bo_device {
 	/*
 	 * Constant after bo device init / atomic.
 	 */
-
-	struct ttm_mem_global *mem_glob;
+	struct list_head device_list;
+	struct ttm_bo_global *glob;
 	struct ttm_bo_driver *driver;
-	struct page *dummy_read_page;
-	struct ttm_mem_shrink shrink;
-
-	size_t ttm_bo_extra_size;
-	size_t ttm_bo_size;
-
 	rwlock_t vm_lock;
+	struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
 	/*
 	 * Protected by the vm lock.
 	 */
-	struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
 	struct rb_root addr_space_rb;
 	struct drm_mm addr_space_mm;
 
 	/*
-	 * Might want to change this to one lock per manager.
-	 */
-	spinlock_t lru_lock;
-	/*
-	 * Protected by the lru lock.
+	 * Protected by the global:lru lock.
 	 */
 	struct list_head ddestroy;
-	struct list_head swap_lru;
 
 	/*
 	 * Protected by load / firstopen / lastclose /unload sync.
@@ -629,6 +668,9 @@ extern int ttm_bo_pci_offset(struct ttm_bo_device *bdev,
 			     unsigned long *bus_offset,
 			     unsigned long *bus_size);
 
+extern void ttm_bo_global_release(struct ttm_global_reference *ref);
+extern int ttm_bo_global_init(struct ttm_global_reference *ref);
+
 extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
 
 /**
@@ -646,7 +688,7 @@ extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
  * !0: Failure.
  */
 extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
-			      struct ttm_mem_global *mem_glob,
+			      struct ttm_bo_global *glob,
 			      struct ttm_bo_driver *driver,
 			      uint64_t file_page_offset);