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);