1 /**************************************************************************
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
27 **************************************************************************/
30 * Generic simple memory manager implementation. Intended to be used as a base
31 * class implementation for more advanced memory managers.
33 * Note that the algorithm used is quite simple and there might be substantial
34 * performance gains if a smarter free list is implemented. Currently it is just an
35 * unordered stack of free regions. This could easily be improved if an RB-tree
36 * is used instead. At least if we expect heavy fragmentation.
38 * Aligned allocations can also see improvement.
41 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
45 #include <drm/drm_mm.h>
46 #include <linux/slab.h>
47 #include <linux/seq_file.h>
48 #include <linux/export.h>
49 #include <linux/interval_tree_generic.h>
54 * drm_mm provides a simple range allocator. The drivers are free to use the
55 * resource allocator from the linux core if it suits them, the upside of drm_mm
56 * is that it's in the DRM core. Which means that it's easier to extend for
57 * some of the crazier special purpose needs of gpus.
59 * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node.
60 * Drivers are free to embed either of them into their own suitable
61 * datastructures. drm_mm itself will not do any allocations of its own, so if
62 * drivers choose not to embed nodes they need to still allocate them
65 * The range allocator also supports reservation of preallocated blocks. This is
66 * useful for taking over initial mode setting configurations from the firmware,
67 * where an object needs to be created which exactly matches the firmware's
68 * scanout target. As long as the range is still free it can be inserted anytime
69 * after the allocator is initialized, which helps with avoiding looped
70 * depencies in the driver load sequence.
72 * drm_mm maintains a stack of most recently freed holes, which of all
73 * simplistic datastructures seems to be a fairly decent approach to clustering
74 * allocations and avoiding too much fragmentation. This means free space
75 * searches are O(num_holes). Given that all the fancy features drm_mm supports
76 * something better would be fairly complex and since gfx thrashing is a fairly
77 * steep cliff not a real concern. Removing a node again is O(1).
79 * drm_mm supports a few features: Alignment and range restrictions can be
80 * supplied. Further more every &drm_mm_node has a color value (which is just an
81 * opaqua unsigned long) which in conjunction with a driver callback can be used
82 * to implement sophisticated placement restrictions. The i915 DRM driver uses
83 * this to implement guard pages between incompatible caching domains in the
86 * Two behaviors are supported for searching and allocating: bottom-up and top-down.
87 * The default is bottom-up. Top-down allocation can be used if the memory area
88 * has different restrictions, or just to reduce fragmentation.
90 * Finally iteration helpers to walk all nodes and all holes are provided as are
91 * some basic allocator dumpers for debugging.
94 static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
98 enum drm_mm_search_flags flags);
99 static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
105 enum drm_mm_search_flags flags);
107 #ifdef CONFIG_DRM_DEBUG_MM
108 #include <linux/stackdepot.h>
110 #define STACKDEPTH 32
113 static noinline void save_stack(struct drm_mm_node *node)
115 unsigned long entries[STACKDEPTH];
116 struct stack_trace trace = {
118 .max_entries = STACKDEPTH,
122 save_stack_trace(&trace);
123 if (trace.nr_entries != 0 &&
124 trace.entries[trace.nr_entries-1] == ULONG_MAX)
127 /* May be called under spinlock, so avoid sleeping */
128 node->stack = depot_save_stack(&trace, GFP_NOWAIT);
131 static void show_leaks(struct drm_mm *mm)
133 struct drm_mm_node *node;
134 unsigned long entries[STACKDEPTH];
137 buf = kmalloc(BUFSZ, GFP_KERNEL);
141 list_for_each_entry(node, &mm->head_node.node_list, node_list) {
142 struct stack_trace trace = {
144 .max_entries = STACKDEPTH
148 DRM_ERROR("node [%08llx + %08llx]: unknown owner\n",
149 node->start, node->size);
153 depot_fetch_stack(node->stack, &trace);
154 snprint_stack_trace(buf, BUFSZ, &trace, 0);
155 DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s",
156 node->start, node->size, buf);
165 static void save_stack(struct drm_mm_node *node) { }
166 static void show_leaks(struct drm_mm *mm) { }
169 #define START(node) ((node)->start)
170 #define LAST(node) ((node)->start + (node)->size - 1)
172 INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
174 START, LAST, static inline, drm_mm_interval_tree)
177 __drm_mm_interval_first(struct drm_mm *mm, u64 start, u64 last)
179 return drm_mm_interval_tree_iter_first(&mm->interval_tree,
182 EXPORT_SYMBOL(__drm_mm_interval_first);
184 static void drm_mm_interval_tree_add_node(struct drm_mm_node *hole_node,
185 struct drm_mm_node *node)
187 struct drm_mm *mm = hole_node->mm;
188 struct rb_node **link, *rb;
189 struct drm_mm_node *parent;
191 node->__subtree_last = LAST(node);
193 if (hole_node->allocated) {
196 parent = rb_entry(rb, struct drm_mm_node, rb);
197 if (parent->__subtree_last >= node->__subtree_last)
200 parent->__subtree_last = node->__subtree_last;
205 link = &hole_node->rb.rb_right;
208 link = &mm->interval_tree.rb_node;
213 parent = rb_entry(rb, struct drm_mm_node, rb);
214 if (parent->__subtree_last < node->__subtree_last)
215 parent->__subtree_last = node->__subtree_last;
216 if (node->start < parent->start)
217 link = &parent->rb.rb_left;
219 link = &parent->rb.rb_right;
222 rb_link_node(&node->rb, rb, link);
223 rb_insert_augmented(&node->rb,
225 &drm_mm_interval_tree_augment);
228 static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
229 struct drm_mm_node *node,
230 u64 size, unsigned alignment,
232 enum drm_mm_allocator_flags flags)
234 struct drm_mm *mm = hole_node->mm;
235 u64 hole_start = drm_mm_hole_node_start(hole_node);
236 u64 hole_end = drm_mm_hole_node_end(hole_node);
237 u64 adj_start = hole_start;
238 u64 adj_end = hole_end;
240 BUG_ON(node->allocated);
242 if (mm->color_adjust)
243 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
245 if (flags & DRM_MM_CREATE_TOP)
246 adj_start = adj_end - size;
252 rem = do_div(tmp, alignment);
254 if (flags & DRM_MM_CREATE_TOP)
257 adj_start += alignment - rem;
261 BUG_ON(adj_start < hole_start);
262 BUG_ON(adj_end > hole_end);
264 if (adj_start == hole_start) {
265 hole_node->hole_follows = 0;
266 list_del(&hole_node->hole_stack);
269 node->start = adj_start;
275 list_add(&node->node_list, &hole_node->node_list);
277 drm_mm_interval_tree_add_node(hole_node, node);
279 BUG_ON(node->start + node->size > adj_end);
281 node->hole_follows = 0;
282 if (__drm_mm_hole_node_start(node) < hole_end) {
283 list_add(&node->hole_stack, &mm->hole_stack);
284 node->hole_follows = 1;
291 * drm_mm_reserve_node - insert an pre-initialized node
292 * @mm: drm_mm allocator to insert @node into
293 * @node: drm_mm_node to insert
295 * This functions inserts an already set-up drm_mm_node into the allocator,
296 * meaning that start, size and color must be set by the caller. This is useful
297 * to initialize the allocator with preallocated objects which must be set-up
298 * before the range allocator can be set-up, e.g. when taking over a firmware
302 * 0 on success, -ENOSPC if there's no hole where @node is.
304 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
306 u64 end = node->start + node->size;
307 struct drm_mm_node *hole;
308 u64 hole_start, hole_end;
309 u64 adj_start, adj_end;
311 if (WARN_ON(node->size == 0))
314 end = node->start + node->size;
316 /* Find the relevant hole to add our node to */
317 hole = drm_mm_interval_tree_iter_first(&mm->interval_tree,
318 node->start, ~(u64)0);
320 if (hole->start < end)
323 hole = list_entry(&mm->head_node.node_list,
324 typeof(*hole), node_list);
327 hole = list_last_entry(&hole->node_list, typeof(*hole), node_list);
328 if (!hole->hole_follows)
331 adj_start = hole_start = __drm_mm_hole_node_start(hole);
332 adj_end = hole_end = __drm_mm_hole_node_end(hole);
334 if (mm->color_adjust)
335 mm->color_adjust(hole, node->color, &adj_start, &adj_end);
337 if (adj_start > node->start || adj_end < end)
343 list_add(&node->node_list, &hole->node_list);
345 drm_mm_interval_tree_add_node(hole, node);
347 if (node->start == hole_start) {
348 hole->hole_follows = 0;
349 list_del(&hole->hole_stack);
352 node->hole_follows = 0;
353 if (end != hole_end) {
354 list_add(&node->hole_stack, &mm->hole_stack);
355 node->hole_follows = 1;
362 EXPORT_SYMBOL(drm_mm_reserve_node);
365 * drm_mm_insert_node_generic - search for space and insert @node
366 * @mm: drm_mm to allocate from
367 * @node: preallocate node to insert
368 * @size: size of the allocation
369 * @alignment: alignment of the allocation
370 * @color: opaque tag value to use for this node
371 * @sflags: flags to fine-tune the allocation search
372 * @aflags: flags to fine-tune the allocation behavior
374 * The preallocated node must be cleared to 0.
377 * 0 on success, -ENOSPC if there's no suitable hole.
379 int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
380 u64 size, unsigned alignment,
382 enum drm_mm_search_flags sflags,
383 enum drm_mm_allocator_flags aflags)
385 struct drm_mm_node *hole_node;
387 if (WARN_ON(size == 0))
390 hole_node = drm_mm_search_free_generic(mm, size, alignment,
395 drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags);
398 EXPORT_SYMBOL(drm_mm_insert_node_generic);
400 static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
401 struct drm_mm_node *node,
402 u64 size, unsigned alignment,
405 enum drm_mm_allocator_flags flags)
407 struct drm_mm *mm = hole_node->mm;
408 u64 hole_start = drm_mm_hole_node_start(hole_node);
409 u64 hole_end = drm_mm_hole_node_end(hole_node);
410 u64 adj_start = hole_start;
411 u64 adj_end = hole_end;
413 BUG_ON(!hole_node->hole_follows || node->allocated);
415 if (adj_start < start)
420 if (mm->color_adjust)
421 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
423 if (flags & DRM_MM_CREATE_TOP)
424 adj_start = adj_end - size;
430 rem = do_div(tmp, alignment);
432 if (flags & DRM_MM_CREATE_TOP)
435 adj_start += alignment - rem;
439 if (adj_start == hole_start) {
440 hole_node->hole_follows = 0;
441 list_del(&hole_node->hole_stack);
444 node->start = adj_start;
450 list_add(&node->node_list, &hole_node->node_list);
452 drm_mm_interval_tree_add_node(hole_node, node);
454 BUG_ON(node->start < start);
455 BUG_ON(node->start < adj_start);
456 BUG_ON(node->start + node->size > adj_end);
457 BUG_ON(node->start + node->size > end);
459 node->hole_follows = 0;
460 if (__drm_mm_hole_node_start(node) < hole_end) {
461 list_add(&node->hole_stack, &mm->hole_stack);
462 node->hole_follows = 1;
469 * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node
470 * @mm: drm_mm to allocate from
471 * @node: preallocate node to insert
472 * @size: size of the allocation
473 * @alignment: alignment of the allocation
474 * @color: opaque tag value to use for this node
475 * @start: start of the allowed range for this node
476 * @end: end of the allowed range for this node
477 * @sflags: flags to fine-tune the allocation search
478 * @aflags: flags to fine-tune the allocation behavior
480 * The preallocated node must be cleared to 0.
483 * 0 on success, -ENOSPC if there's no suitable hole.
485 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
486 u64 size, unsigned alignment,
489 enum drm_mm_search_flags sflags,
490 enum drm_mm_allocator_flags aflags)
492 struct drm_mm_node *hole_node;
494 if (WARN_ON(size == 0))
497 hole_node = drm_mm_search_free_in_range_generic(mm,
498 size, alignment, color,
503 drm_mm_insert_helper_range(hole_node, node,
504 size, alignment, color,
508 EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
511 * drm_mm_remove_node - Remove a memory node from the allocator.
512 * @node: drm_mm_node to remove
514 * This just removes a node from its drm_mm allocator. The node does not need to
515 * be cleared again before it can be re-inserted into this or any other drm_mm
516 * allocator. It is a bug to call this function on a un-allocated node.
518 void drm_mm_remove_node(struct drm_mm_node *node)
520 struct drm_mm *mm = node->mm;
521 struct drm_mm_node *prev_node;
523 if (WARN_ON(!node->allocated))
526 BUG_ON(node->scanned_block || node->scanned_prev_free
527 || node->scanned_next_free);
530 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
532 if (node->hole_follows) {
533 BUG_ON(__drm_mm_hole_node_start(node) ==
534 __drm_mm_hole_node_end(node));
535 list_del(&node->hole_stack);
537 BUG_ON(__drm_mm_hole_node_start(node) !=
538 __drm_mm_hole_node_end(node));
541 if (!prev_node->hole_follows) {
542 prev_node->hole_follows = 1;
543 list_add(&prev_node->hole_stack, &mm->hole_stack);
545 list_move(&prev_node->hole_stack, &mm->hole_stack);
547 drm_mm_interval_tree_remove(node, &mm->interval_tree);
548 list_del(&node->node_list);
551 EXPORT_SYMBOL(drm_mm_remove_node);
553 static int check_free_hole(u64 start, u64 end, u64 size, unsigned alignment)
555 if (end - start < size)
562 rem = do_div(tmp, alignment);
564 start += alignment - rem;
567 return end >= start + size;
570 static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
574 enum drm_mm_search_flags flags)
576 struct drm_mm_node *entry;
577 struct drm_mm_node *best;
582 BUG_ON(mm->scanned_blocks);
587 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
588 flags & DRM_MM_SEARCH_BELOW) {
589 u64 hole_size = adj_end - adj_start;
591 if (mm->color_adjust) {
592 mm->color_adjust(entry, color, &adj_start, &adj_end);
593 if (adj_end <= adj_start)
597 if (!check_free_hole(adj_start, adj_end, size, alignment))
600 if (!(flags & DRM_MM_SEARCH_BEST))
603 if (hole_size < best_size) {
605 best_size = hole_size;
612 static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
618 enum drm_mm_search_flags flags)
620 struct drm_mm_node *entry;
621 struct drm_mm_node *best;
626 BUG_ON(mm->scanned_blocks);
631 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
632 flags & DRM_MM_SEARCH_BELOW) {
633 u64 hole_size = adj_end - adj_start;
635 if (adj_start < start)
640 if (mm->color_adjust) {
641 mm->color_adjust(entry, color, &adj_start, &adj_end);
642 if (adj_end <= adj_start)
646 if (!check_free_hole(adj_start, adj_end, size, alignment))
649 if (!(flags & DRM_MM_SEARCH_BEST))
652 if (hole_size < best_size) {
654 best_size = hole_size;
662 * drm_mm_replace_node - move an allocation from @old to @new
663 * @old: drm_mm_node to remove from the allocator
664 * @new: drm_mm_node which should inherit @old's allocation
666 * This is useful for when drivers embed the drm_mm_node structure and hence
667 * can't move allocations by reassigning pointers. It's a combination of remove
668 * and insert with the guarantee that the allocation start will match.
670 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
672 list_replace(&old->node_list, &new->node_list);
673 list_replace(&old->hole_stack, &new->hole_stack);
674 rb_replace_node(&old->rb, &new->rb, &old->mm->interval_tree);
675 new->hole_follows = old->hole_follows;
677 new->start = old->start;
678 new->size = old->size;
679 new->color = old->color;
680 new->__subtree_last = old->__subtree_last;
685 EXPORT_SYMBOL(drm_mm_replace_node);
688 * DOC: lru scan roaster
690 * Very often GPUs need to have continuous allocations for a given object. When
691 * evicting objects to make space for a new one it is therefore not most
692 * efficient when we simply start to select all objects from the tail of an LRU
693 * until there's a suitable hole: Especially for big objects or nodes that
694 * otherwise have special allocation constraints there's a good chance we evict
695 * lots of (smaller) objects unecessarily.
697 * The DRM range allocator supports this use-case through the scanning
698 * interfaces. First a scan operation needs to be initialized with
699 * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds
700 * objects to the roaster (probably by walking an LRU list, but this can be
701 * freely implemented) until a suitable hole is found or there's no further
704 * The the driver must walk through all objects again in exactly the reverse
705 * order to restore the allocator state. Note that while the allocator is used
706 * in the scan mode no other operation is allowed.
708 * Finally the driver evicts all objects selected in the scan. Adding and
709 * removing an object is O(1), and since freeing a node is also O(1) the overall
710 * complexity is O(scanned_objects). So like the free stack which needs to be
711 * walked before a scan operation even begins this is linear in the number of
712 * objects. It doesn't seem to hurt badly.
716 * drm_mm_init_scan - initialize lru scanning
717 * @mm: drm_mm to scan
718 * @size: size of the allocation
719 * @alignment: alignment of the allocation
720 * @color: opaque tag value to use for the allocation
722 * This simply sets up the scanning routines with the parameters for the desired
723 * hole. Note that there's no need to specify allocation flags, since they only
724 * change the place a node is allocated from within a suitable hole.
727 * As long as the scan list is non-empty, no other operations than
728 * adding/removing nodes to/from the scan list are allowed.
730 void drm_mm_init_scan(struct drm_mm *mm,
735 mm->scan_color = color;
736 mm->scan_alignment = alignment;
737 mm->scan_size = size;
738 mm->scanned_blocks = 0;
739 mm->scan_hit_start = 0;
740 mm->scan_hit_end = 0;
741 mm->scan_check_range = 0;
742 mm->prev_scanned_node = NULL;
744 EXPORT_SYMBOL(drm_mm_init_scan);
747 * drm_mm_init_scan - initialize range-restricted lru scanning
748 * @mm: drm_mm to scan
749 * @size: size of the allocation
750 * @alignment: alignment of the allocation
751 * @color: opaque tag value to use for the allocation
752 * @start: start of the allowed range for the allocation
753 * @end: end of the allowed range for the allocation
755 * This simply sets up the scanning routines with the parameters for the desired
756 * hole. Note that there's no need to specify allocation flags, since they only
757 * change the place a node is allocated from within a suitable hole.
760 * As long as the scan list is non-empty, no other operations than
761 * adding/removing nodes to/from the scan list are allowed.
763 void drm_mm_init_scan_with_range(struct drm_mm *mm,
770 mm->scan_color = color;
771 mm->scan_alignment = alignment;
772 mm->scan_size = size;
773 mm->scanned_blocks = 0;
774 mm->scan_hit_start = 0;
775 mm->scan_hit_end = 0;
776 mm->scan_start = start;
778 mm->scan_check_range = 1;
779 mm->prev_scanned_node = NULL;
781 EXPORT_SYMBOL(drm_mm_init_scan_with_range);
784 * drm_mm_scan_add_block - add a node to the scan list
785 * @node: drm_mm_node to add
787 * Add a node to the scan list that might be freed to make space for the desired
791 * True if a hole has been found, false otherwise.
793 bool drm_mm_scan_add_block(struct drm_mm_node *node)
795 struct drm_mm *mm = node->mm;
796 struct drm_mm_node *prev_node;
797 u64 hole_start, hole_end;
798 u64 adj_start, adj_end;
800 mm->scanned_blocks++;
802 BUG_ON(node->scanned_block);
803 node->scanned_block = 1;
805 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
808 node->scanned_preceeds_hole = prev_node->hole_follows;
809 prev_node->hole_follows = 1;
810 list_del(&node->node_list);
811 node->node_list.prev = &prev_node->node_list;
812 node->node_list.next = &mm->prev_scanned_node->node_list;
813 mm->prev_scanned_node = node;
815 adj_start = hole_start = drm_mm_hole_node_start(prev_node);
816 adj_end = hole_end = drm_mm_hole_node_end(prev_node);
818 if (mm->scan_check_range) {
819 if (adj_start < mm->scan_start)
820 adj_start = mm->scan_start;
821 if (adj_end > mm->scan_end)
822 adj_end = mm->scan_end;
825 if (mm->color_adjust)
826 mm->color_adjust(prev_node, mm->scan_color,
827 &adj_start, &adj_end);
829 if (check_free_hole(adj_start, adj_end,
830 mm->scan_size, mm->scan_alignment)) {
831 mm->scan_hit_start = hole_start;
832 mm->scan_hit_end = hole_end;
838 EXPORT_SYMBOL(drm_mm_scan_add_block);
841 * drm_mm_scan_remove_block - remove a node from the scan list
842 * @node: drm_mm_node to remove
844 * Nodes _must_ be removed in the exact same order from the scan list as they
845 * have been added, otherwise the internal state of the memory manager will be
848 * When the scan list is empty, the selected memory nodes can be freed. An
849 * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then
850 * return the just freed block (because its at the top of the free_stack list).
853 * True if this block should be evicted, false otherwise. Will always
854 * return false when no hole has been found.
856 bool drm_mm_scan_remove_block(struct drm_mm_node *node)
858 struct drm_mm *mm = node->mm;
859 struct drm_mm_node *prev_node;
861 mm->scanned_blocks--;
863 BUG_ON(!node->scanned_block);
864 node->scanned_block = 0;
866 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
869 prev_node->hole_follows = node->scanned_preceeds_hole;
870 list_add(&node->node_list, &prev_node->node_list);
872 return (drm_mm_hole_node_end(node) > mm->scan_hit_start &&
873 node->start < mm->scan_hit_end);
875 EXPORT_SYMBOL(drm_mm_scan_remove_block);
878 * drm_mm_clean - checks whether an allocator is clean
879 * @mm: drm_mm allocator to check
882 * True if the allocator is completely free, false if there's still a node
885 bool drm_mm_clean(struct drm_mm * mm)
887 struct list_head *head = &mm->head_node.node_list;
889 return (head->next->next == head);
891 EXPORT_SYMBOL(drm_mm_clean);
894 * drm_mm_init - initialize a drm-mm allocator
895 * @mm: the drm_mm structure to initialize
896 * @start: start of the range managed by @mm
897 * @size: end of the range managed by @mm
899 * Note that @mm must be cleared to 0 before calling this function.
901 void drm_mm_init(struct drm_mm * mm, u64 start, u64 size)
903 INIT_LIST_HEAD(&mm->hole_stack);
904 mm->scanned_blocks = 0;
906 /* Clever trick to avoid a special case in the free hole tracking. */
907 INIT_LIST_HEAD(&mm->head_node.node_list);
908 mm->head_node.allocated = 0;
909 mm->head_node.hole_follows = 1;
910 mm->head_node.scanned_block = 0;
911 mm->head_node.scanned_prev_free = 0;
912 mm->head_node.scanned_next_free = 0;
913 mm->head_node.mm = mm;
914 mm->head_node.start = start + size;
915 mm->head_node.size = start - mm->head_node.start;
916 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
918 mm->interval_tree = RB_ROOT;
920 mm->color_adjust = NULL;
922 EXPORT_SYMBOL(drm_mm_init);
925 * drm_mm_takedown - clean up a drm_mm allocator
926 * @mm: drm_mm allocator to clean up
928 * Note that it is a bug to call this function on an allocator which is not
931 void drm_mm_takedown(struct drm_mm *mm)
933 if (WARN(!list_empty(&mm->head_node.node_list),
934 "Memory manager not clean during takedown.\n"))
938 EXPORT_SYMBOL(drm_mm_takedown);
940 static u64 drm_mm_debug_hole(struct drm_mm_node *entry,
943 u64 hole_start, hole_end, hole_size;
945 if (entry->hole_follows) {
946 hole_start = drm_mm_hole_node_start(entry);
947 hole_end = drm_mm_hole_node_end(entry);
948 hole_size = hole_end - hole_start;
949 pr_debug("%s %#llx-%#llx: %llu: free\n", prefix, hole_start,
950 hole_end, hole_size);
958 * drm_mm_debug_table - dump allocator state to dmesg
959 * @mm: drm_mm allocator to dump
960 * @prefix: prefix to use for dumping to dmesg
962 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
964 struct drm_mm_node *entry;
965 u64 total_used = 0, total_free = 0, total = 0;
967 total_free += drm_mm_debug_hole(&mm->head_node, prefix);
969 drm_mm_for_each_node(entry, mm) {
970 pr_debug("%s %#llx-%#llx: %llu: used\n", prefix, entry->start,
971 entry->start + entry->size, entry->size);
972 total_used += entry->size;
973 total_free += drm_mm_debug_hole(entry, prefix);
975 total = total_free + total_used;
977 pr_debug("%s total: %llu, used %llu free %llu\n", prefix, total,
978 total_used, total_free);
980 EXPORT_SYMBOL(drm_mm_debug_table);
982 #if defined(CONFIG_DEBUG_FS)
983 static u64 drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
985 u64 hole_start, hole_end, hole_size;
987 if (entry->hole_follows) {
988 hole_start = drm_mm_hole_node_start(entry);
989 hole_end = drm_mm_hole_node_end(entry);
990 hole_size = hole_end - hole_start;
991 seq_printf(m, "%#018llx-%#018llx: %llu: free\n", hole_start,
992 hole_end, hole_size);
1000 * drm_mm_dump_table - dump allocator state to a seq_file
1001 * @m: seq_file to dump to
1002 * @mm: drm_mm allocator to dump
1004 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
1006 struct drm_mm_node *entry;
1007 u64 total_used = 0, total_free = 0, total = 0;
1009 total_free += drm_mm_dump_hole(m, &mm->head_node);
1011 drm_mm_for_each_node(entry, mm) {
1012 seq_printf(m, "%#018llx-%#018llx: %llu: used\n", entry->start,
1013 entry->start + entry->size, entry->size);
1014 total_used += entry->size;
1015 total_free += drm_mm_dump_hole(m, entry);
1017 total = total_free + total_used;
1019 seq_printf(m, "total: %llu, used %llu free %llu\n", total,
1020 total_used, total_free);
1023 EXPORT_SYMBOL(drm_mm_dump_table);