5 files changed, 254 insertions, 144 deletions

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 2ac074c8f5d2..da99edc50888 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -48,44 +48,14 @@
 
 #define MM_UNUSED_TARGET 4
 
-unsigned long drm_mm_tail_space(struct drm_mm *mm)
-{
-	struct list_head *tail_node;
-	struct drm_mm_node *entry;
-
-	tail_node = mm->ml_entry.prev;
-	entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
-	if (!entry->free)
-		return 0;
-
-	return entry->size;
-}
-
-int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size)
-{
-	struct list_head *tail_node;
-	struct drm_mm_node *entry;
-
-	tail_node = mm->ml_entry.prev;
-	entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
-	if (!entry->free)
-		return -ENOMEM;
-
-	if (entry->size <= size)
-		return -ENOMEM;
-
-	entry->size -= size;
-	return 0;
-}
-
 static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
 {
 	struct drm_mm_node *child;
 
 	if (atomic)
-		child = kmalloc(sizeof(*child), GFP_ATOMIC);
+		child = kzalloc(sizeof(*child), GFP_ATOMIC);
 	else
-		child = kmalloc(sizeof(*child), GFP_KERNEL);
+		child = kzalloc(sizeof(*child), GFP_KERNEL);
 
 	if (unlikely(child == NULL)) {
 		spin_lock(&mm->unused_lock);
@@ -94,8 +64,8 @@ static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
 		else {
 			child =
 			    list_entry(mm->unused_nodes.next,
-				       struct drm_mm_node, fl_entry);
-			list_del(&child->fl_entry);
+				       struct drm_mm_node, free_stack);
+			list_del(&child->free_stack);
 			--mm->num_unused;
 		}
 		spin_unlock(&mm->unused_lock);
@@ -115,7 +85,7 @@ int drm_mm_pre_get(struct drm_mm *mm)
 	spin_lock(&mm->unused_lock);
 	while (mm->num_unused < MM_UNUSED_TARGET) {
 		spin_unlock(&mm->unused_lock);
-		node = kmalloc(sizeof(*node), GFP_KERNEL);
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
 		spin_lock(&mm->unused_lock);
 
 		if (unlikely(node == NULL)) {
@@ -124,7 +94,7 @@ int drm_mm_pre_get(struct drm_mm *mm)
 			return ret;
 		}
 		++mm->num_unused;
-		list_add_tail(&node->fl_entry, &mm->unused_nodes);
+		list_add_tail(&node->free_stack, &mm->unused_nodes);
 	}
 	spin_unlock(&mm->unused_lock);
 	return 0;
@@ -146,27 +116,12 @@ static int drm_mm_create_tail_node(struct drm_mm *mm,
 	child->start = start;
 	child->mm = mm;
 
-	list_add_tail(&child->ml_entry, &mm->ml_entry);
-	list_add_tail(&child->fl_entry, &mm->fl_entry);
+	list_add_tail(&child->node_list, &mm->node_list);
+	list_add_tail(&child->free_stack, &mm->free_stack);
 
 	return 0;
 }
 
-int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size, int atomic)
-{
-	struct list_head *tail_node;
-	struct drm_mm_node *entry;
-
-	tail_node = mm->ml_entry.prev;
-	entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
-	if (!entry->free) {
-		return drm_mm_create_tail_node(mm, entry->start + entry->size,
-					       size, atomic);
-	}
-	entry->size += size;
-	return 0;
-}
-
 static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
 						 unsigned long size,
 						 int atomic)
@@ -177,15 +132,14 @@ static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
 	if (unlikely(child == NULL))
 		return NULL;
 
-	INIT_LIST_HEAD(&child->fl_entry);
+	INIT_LIST_HEAD(&child->free_stack);
 
-	child->free = 0;
 	child->size = size;
 	child->start = parent->start;
 	child->mm = parent->mm;
 
-	list_add_tail(&child->ml_entry, &parent->ml_entry);
-	INIT_LIST_HEAD(&child->fl_entry);
+	list_add_tail(&child->node_list, &parent->node_list);
+	INIT_LIST_HEAD(&child->free_stack);
 
 	parent->size -= size;
 	parent->start += size;
@@ -213,7 +167,7 @@ struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
 	}
 
 	if (node->size == size) {
-		list_del_init(&node->fl_entry);
+		list_del_init(&node->free_stack);
 		node->free = 0;
 	} else {
 		node = drm_mm_split_at_start(node, size, atomic);
@@ -251,7 +205,7 @@ struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *node,
 	}
 
 	if (node->size == size) {
-		list_del_init(&node->fl_entry);
+		list_del_init(&node->free_stack);
 		node->free = 0;
 	} else {
 		node = drm_mm_split_at_start(node, size, atomic);
@@ -273,16 +227,19 @@ void drm_mm_put_block(struct drm_mm_node *cur)
 {
 
 	struct drm_mm *mm = cur->mm;
-	struct list_head *cur_head = &cur->ml_entry;
-	struct list_head *root_head = &mm->ml_entry;
+	struct list_head *cur_head = &cur->node_list;
+	struct list_head *root_head = &mm->node_list;
 	struct drm_mm_node *prev_node = NULL;
 	struct drm_mm_node *next_node;
 
 	int merged = 0;
 
+	BUG_ON(cur->scanned_block || cur->scanned_prev_free
+				  || cur->scanned_next_free);
+
 	if (cur_head->prev != root_head) {
 		prev_node =
-		    list_entry(cur_head->prev, struct drm_mm_node, ml_entry);
+		    list_entry(cur_head->prev, struct drm_mm_node, node_list);
 		if (prev_node->free) {
 			prev_node->size += cur->size;
 			merged = 1;
@@ -290,15 +247,15 @@ void drm_mm_put_block(struct drm_mm_node *cur)
 	}
 	if (cur_head->next != root_head) {
 		next_node =
-		    list_entry(cur_head->next, struct drm_mm_node, ml_entry);
+		    list_entry(cur_head->next, struct drm_mm_node, node_list);
 		if (next_node->free) {
 			if (merged) {
 				prev_node->size += next_node->size;
-				list_del(&next_node->ml_entry);
-				list_del(&next_node->fl_entry);
+				list_del(&next_node->node_list);
+				list_del(&next_node->free_stack);
 				spin_lock(&mm->unused_lock);
 				if (mm->num_unused < MM_UNUSED_TARGET) {
-					list_add(&next_node->fl_entry,
+					list_add(&next_node->free_stack,
 						 &mm->unused_nodes);
 					++mm->num_unused;
 				} else
@@ -313,12 +270,12 @@ void drm_mm_put_block(struct drm_mm_node *cur)
 	}
 	if (!merged) {
 		cur->free = 1;
-		list_add(&cur->fl_entry, &mm->fl_entry);
+		list_add(&cur->free_stack, &mm->free_stack);
 	} else {
-		list_del(&cur->ml_entry);
+		list_del(&cur->node_list);
 		spin_lock(&mm->unused_lock);
 		if (mm->num_unused < MM_UNUSED_TARGET) {
-			list_add(&cur->fl_entry, &mm->unused_nodes);
+			list_add(&cur->free_stack, &mm->unused_nodes);
 			++mm->num_unused;
 		} else
 			kfree(cur);
@@ -328,40 +285,50 @@ void drm_mm_put_block(struct drm_mm_node *cur)
 
 EXPORT_SYMBOL(drm_mm_put_block);
 
+static int check_free_mm_node(struct drm_mm_node *entry, unsigned long size,
+			      unsigned alignment)
+{
+	unsigned wasted = 0;
+
+	if (entry->size < size)
+		return 0;
+
+	if (alignment) {
+		register unsigned tmp = entry->start % alignment;
+		if (tmp)
+			wasted = alignment - tmp;
+	}
+
+	if (entry->size >= size + wasted) {
+		return 1;
+	}
+
+	return 0;
+}
+
 struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
 				       unsigned long size,
 				       unsigned alignment, int best_match)
 {
-	struct list_head *list;
-	const struct list_head *free_stack = &mm->fl_entry;
 	struct drm_mm_node *entry;
 	struct drm_mm_node *best;
 	unsigned long best_size;
-	unsigned wasted;
+
+	BUG_ON(mm->scanned_blocks);
 
 	best = NULL;
 	best_size = ~0UL;
 
-	list_for_each(list, free_stack) {
-		entry = list_entry(list, struct drm_mm_node, fl_entry);
-		wasted = 0;
-
-		if (entry->size < size)
+	list_for_each_entry(entry, &mm->free_stack, free_stack) {
+		if (!check_free_mm_node(entry, size, alignment))
 			continue;
 
-		if (alignment) {
-			register unsigned tmp = entry->start % alignment;
-			if (tmp)
-				wasted += alignment - tmp;
-		}
+		if (!best_match)
+			return entry;
 
-		if (entry->size >= size + wasted) {
-			if (!best_match)
-				return entry;
-			if (entry->size < best_size) {
-				best = entry;
-				best_size = entry->size;
-			}
+		if (entry->size < best_size) {
+			best = entry;
+			best_size = entry->size;
 		}
 	}
 
@@ -376,43 +343,28 @@ struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
 						unsigned long end,
 						int best_match)
 {
-	struct list_head *list;
-	const struct list_head *free_stack = &mm->fl_entry;
 	struct drm_mm_node *entry;
 	struct drm_mm_node *best;
 	unsigned long best_size;
-	unsigned wasted;
+
+	BUG_ON(mm->scanned_blocks);
 
 	best = NULL;
 	best_size = ~0UL;
 
-	list_for_each(list, free_stack) {
-		entry = list_entry(list, struct drm_mm_node, fl_entry);
-		wasted = 0;
-
-		if (entry->size < size)
-			continue;
-
+	list_for_each_entry(entry, &mm->free_stack, free_stack) {
 		if (entry->start > end || (entry->start+entry->size) < start)
 			continue;
 
-		if (entry->start < start)
-			wasted += start - entry->start;
+		if (!check_free_mm_node(entry, size, alignment))
+			continue;
 
-		if (alignment) {
-			register unsigned tmp = (entry->start + wasted) % alignment;
-			if (tmp)
-				wasted += alignment - tmp;
-		}
+		if (!best_match)
+			return entry;
 
-		if (entry->size >= size + wasted &&
-		    (entry->start + wasted + size) <= end) {
-			if (!best_match)
-				return entry;
-			if (entry->size < best_size) {
-				best = entry;
-				best_size = entry->size;
-			}
+		if (entry->size < best_size) {
+			best = entry;
+			best_size = entry->size;
 		}
 	}
 
@@ -420,9 +372,161 @@ struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
 }
 EXPORT_SYMBOL(drm_mm_search_free_in_range);
 
+/**
+ * Initializa lru scanning.
+ *
+ * This simply sets up the scanning routines with the parameters for the desired
+ * hole.
+ *
+ * Warning: As long as the scan list is non-empty, no other operations than
+ * adding/removing nodes to/from the scan list are allowed.
+ */
+void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
+		      unsigned alignment)
+{
+	mm->scan_alignment = alignment;
+	mm->scan_size = size;
+	mm->scanned_blocks = 0;
+	mm->scan_hit_start = 0;
+	mm->scan_hit_size = 0;
+}
+EXPORT_SYMBOL(drm_mm_init_scan);
+
+/**
+ * Add a node to the scan list that might be freed to make space for the desired
+ * hole.
+ *
+ * Returns non-zero, if a hole has been found, zero otherwise.
+ */
+int drm_mm_scan_add_block(struct drm_mm_node *node)
+{
+	struct drm_mm *mm = node->mm;
+	struct list_head *prev_free, *next_free;
+	struct drm_mm_node *prev_node, *next_node;
+
+	mm->scanned_blocks++;
+
+	prev_free = next_free = NULL;
+
+	BUG_ON(node->free);
+	node->scanned_block = 1;
+	node->free = 1;
+
+	if (node->node_list.prev != &mm->node_list) {
+		prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
+				       node_list);
+
+		if (prev_node->free) {
+			list_del(&prev_node->node_list);
+
+			node->start = prev_node->start;
+			node->size += prev_node->size;
+
+			prev_node->scanned_prev_free = 1;
+
+			prev_free = &prev_node->free_stack;
+		}
+	}
+
+	if (node->node_list.next != &mm->node_list) {
+		next_node = list_entry(node->node_list.next, struct drm_mm_node,
+				       node_list);
+
+		if (next_node->free) {
+			list_del(&next_node->node_list);
+
+			node->size += next_node->size;
+
+			next_node->scanned_next_free = 1;
+
+			next_free = &next_node->free_stack;
+		}
+	}
+
+	/* The free_stack list is not used for allocated objects, so these two
+	 * pointers can be abused (as long as no allocations in this memory
+	 * manager happens). */
+	node->free_stack.prev = prev_free;
+	node->free_stack.next = next_free;
+
+	if (check_free_mm_node(node, mm->scan_size, mm->scan_alignment)) {
+		mm->scan_hit_start = node->start;
+		mm->scan_hit_size = node->size;
+
+		return 1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_mm_scan_add_block);
+
+/**
+ * Remove a node from the scan list.
+ *
+ * Nodes _must_ be removed in the exact same order from the scan list as they
+ * have been added, otherwise the internal state of the memory manager will be
+ * corrupted.
+ *
+ * When the scan list is empty, the selected memory nodes can be freed. An
+ * immediatly following drm_mm_search_free with best_match = 0 will then return
+ * the just freed block (because its at the top of the free_stack list).
+ *
+ * Returns one if this block should be evicted, zero otherwise. Will always
+ * return zero when no hole has been found.
+ */
+int drm_mm_scan_remove_block(struct drm_mm_node *node)
+{
+	struct drm_mm *mm = node->mm;
+	struct drm_mm_node *prev_node, *next_node;
+
+	mm->scanned_blocks--;
+
+	BUG_ON(!node->scanned_block);
+	node->scanned_block = 0;
+	node->free = 0;
+
+	prev_node = list_entry(node->free_stack.prev, struct drm_mm_node,
+			       free_stack);
+	next_node = list_entry(node->free_stack.next, struct drm_mm_node,
+			       free_stack);
+
+	if (prev_node) {
+		BUG_ON(!prev_node->scanned_prev_free);
+		prev_node->scanned_prev_free = 0;
+
+		list_add_tail(&prev_node->node_list, &node->node_list);
+
+		node->start = prev_node->start + prev_node->size;
+		node->size -= prev_node->size;
+	}
+
+	if (next_node) {
+		BUG_ON(!next_node->scanned_next_free);
+		next_node->scanned_next_free = 0;
+
+		list_add(&next_node->node_list, &node->node_list);
+
+		node->size -= next_node->size;
+	}
+
+	INIT_LIST_HEAD(&node->free_stack);
+
+	/* Only need to check for containement because start&size for the
+	 * complete resulting free block (not just the desired part) is
+	 * stored. */
+	if (node->start >= mm->scan_hit_start &&
+	    node->start + node->size
+	    		<= mm->scan_hit_start + mm->scan_hit_size) {
+		return 1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_mm_scan_remove_block);
+
 int drm_mm_clean(struct drm_mm * mm)
 {
-	struct list_head *head = &mm->ml_entry;
+	struct list_head *head = &mm->node_list;
 
 	return (head->next->next == head);
 }
@@ -430,10 +534,11 @@ EXPORT_SYMBOL(drm_mm_clean);
 
 int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
 {
-	INIT_LIST_HEAD(&mm->ml_entry);
-	INIT_LIST_HEAD(&mm->fl_entry);
+	INIT_LIST_HEAD(&mm->node_list);
+	INIT_LIST_HEAD(&mm->free_stack);
 	INIT_LIST_HEAD(&mm->unused_nodes);
 	mm->num_unused = 0;
+	mm->scanned_blocks = 0;
 	spin_lock_init(&mm->unused_lock);
 
 	return drm_mm_create_tail_node(mm, start, size, 0);
@@ -442,25 +547,25 @@ EXPORT_SYMBOL(drm_mm_init);
 
 void drm_mm_takedown(struct drm_mm * mm)
 {
-	struct list_head *bnode = mm->fl_entry.next;
+	struct list_head *bnode = mm->free_stack.next;
 	struct drm_mm_node *entry;
 	struct drm_mm_node *next;
 
-	entry = list_entry(bnode, struct drm_mm_node, fl_entry);
+	entry = list_entry(bnode, struct drm_mm_node, free_stack);
 
-	if (entry->ml_entry.next != &mm->ml_entry ||
-	    entry->fl_entry.next != &mm->fl_entry) {
+	if (entry->node_list.next != &mm->node_list ||
+	    entry->free_stack.next != &mm->free_stack) {
 		DRM_ERROR("Memory manager not clean. Delaying takedown\n");
 		return;
 	}
 
-	list_del(&entry->fl_entry);
-	list_del(&entry->ml_entry);
+	list_del(&entry->free_stack);
+	list_del(&entry->node_list);
 	kfree(entry);
 
 	spin_lock(&mm->unused_lock);
-	list_for_each_entry_safe(entry, next, &mm->unused_nodes, fl_entry) {
-		list_del(&entry->fl_entry);
+	list_for_each_entry_safe(entry, next, &mm->unused_nodes, free_stack) {
+		list_del(&entry->free_stack);
 		kfree(entry);
 		--mm->num_unused;
 	}
@@ -475,7 +580,7 @@ void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
 	struct drm_mm_node *entry;
 	int total_used = 0, total_free = 0, total = 0;
 
-	list_for_each_entry(entry, &mm->ml_entry, ml_entry) {
+	list_for_each_entry(entry, &mm->node_list, node_list) {
 		printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8ld: %s\n",
 			prefix, entry->start, entry->start + entry->size,
 			entry->size, entry->free ? "free" : "used");
@@ -496,7 +601,7 @@ int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
 	struct drm_mm_node *entry;
 	int total_used = 0, total_free = 0, total = 0;
 
-	list_for_each_entry(entry, &mm->ml_entry, ml_entry) {
+	list_for_each_entry(entry, &mm->node_list, node_list) {
 		seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: %s\n", entry->start, entry->start + entry->size, entry->size, entry->free ? "free" : "used");
 		total += entry->size;
 		if (entry->free)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 074385882ccf..75061b305b8c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2633,10 +2633,8 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj, unsigned alignment)
 	if (free_space != NULL) {
 		obj_priv->gtt_space = drm_mm_get_block(free_space, obj->size,
 						       alignment);
-		if (obj_priv->gtt_space != NULL) {
-			obj_priv->gtt_space->private = obj;
+		if (obj_priv->gtt_space != NULL)
 			obj_priv->gtt_offset = obj_priv->gtt_space->start;
-		}
 	}
 	if (obj_priv->gtt_space == NULL) {
 		/* If the gtt is empty and we're still having trouble
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 555ebb12ace8..9763288c6b2d 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -476,7 +476,6 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 			++put_count;
 		}
 		if (bo->mem.mm_node) {
-			bo->mem.mm_node->private = NULL;
 			drm_mm_put_block(bo->mem.mm_node);
 			bo->mem.mm_node = NULL;
 		}
@@ -670,7 +669,6 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
 			printk(KERN_ERR TTM_PFX "Buffer eviction failed\n");
 		spin_lock(&glob->lru_lock);
 		if (evict_mem.mm_node) {
-			evict_mem.mm_node->private = NULL;
 			drm_mm_put_block(evict_mem.mm_node);
 			evict_mem.mm_node = NULL;
 		}
@@ -929,8 +927,6 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 		mem->mm_node = node;
 		mem->mem_type = mem_type;
 		mem->placement = cur_flags;
-		if (node)
-			node->private = bo;
 		return 0;
 	}
 
@@ -973,7 +969,6 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 						interruptible, no_wait_reserve, no_wait_gpu);
 		if (ret == 0 && mem->mm_node) {
 			mem->placement = cur_flags;
-			mem->mm_node->private = bo;
 			return 0;
 		}
 		if (ret == -ERESTARTSYS)
@@ -1029,7 +1024,6 @@ int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 out_unlock:
 	if (ret && mem.mm_node) {
 		spin_lock(&glob->lru_lock);
-		mem.mm_node->private = NULL;
 		drm_mm_put_block(mem.mm_node);
 		spin_unlock(&glob->lru_lock);
 	}
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 13012a1f1486..7cffb3e04232 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -353,8 +353,6 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 	fbo->vm_node = NULL;
 
 	fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
-	if (fbo->mem.mm_node)
-		fbo->mem.mm_node->private = (void *)fbo;
 	kref_init(&fbo->list_kref);
 	kref_init(&fbo->kref);
 	fbo->destroy = &ttm_transfered_destroy;
diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index 4c10be39a43b..bf01531193d5 100644
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -42,21 +42,31 @@
 #endif
 
 struct drm_mm_node {
-	struct list_head fl_entry;
-	struct list_head ml_entry;
-	int free;
+	struct list_head free_stack;
+	struct list_head node_list;
+	unsigned free : 1;
+	unsigned scanned_block : 1;
+	unsigned scanned_prev_free : 1;
+	unsigned scanned_next_free : 1;
 	unsigned long start;
 	unsigned long size;
 	struct drm_mm *mm;
-	void *private;
 };
 
 struct drm_mm {
-	struct list_head fl_entry;
-	struct list_head ml_entry;
+	/* List of free memory blocks, most recently freed ordered. */
+	struct list_head free_stack;
+	/* List of all memory nodes, ordered according to the (increasing) start
+	 * address of the memory node. */
+	struct list_head node_list;
 	struct list_head unused_nodes;
 	int num_unused;
 	spinlock_t unused_lock;
+	unsigned scan_alignment;
+	unsigned long scan_size;
+	unsigned long scan_hit_start;
+	unsigned scan_hit_size;
+	unsigned scanned_blocks;
 };
 
 /*
@@ -133,6 +143,11 @@ static inline struct drm_mm *drm_get_mm(struct drm_mm_node *block)
 	return block->mm;
 }
 
+void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
+		      unsigned alignment);
+int drm_mm_scan_add_block(struct drm_mm_node *node);
+int drm_mm_scan_remove_block(struct drm_mm_node *node);
+
 extern void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
 #ifdef CONFIG_DEBUG_FS
 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);