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>
53 * drm_mm provides a simple range allocator. The drivers are free to use the
54 * resource allocator from the linux core if it suits them, the upside of drm_mm
55 * is that it's in the DRM core. Which means that it's easier to extend for
56 * some of the crazier special purpose needs of gpus.
58 * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node.
59 * Drivers are free to embed either of them into their own suitable
60 * datastructures. drm_mm itself will not do any allocations of its own, so if
61 * drivers choose not to embed nodes they need to still allocate them
64 * The range allocator also supports reservation of preallocated blocks. This is
65 * useful for taking over initial mode setting configurations from the firmware,
66 * where an object needs to be created which exactly matches the firmware's
67 * scanout target. As long as the range is still free it can be inserted anytime
68 * after the allocator is initialized, which helps with avoiding looped
69 * depencies in the driver load sequence.
71 * drm_mm maintains a stack of most recently freed holes, which of all
72 * simplistic datastructures seems to be a fairly decent approach to clustering
73 * allocations and avoiding too much fragmentation. This means free space
74 * searches are O(num_holes). Given that all the fancy features drm_mm supports
75 * something better would be fairly complex and since gfx thrashing is a fairly
76 * steep cliff not a real concern. Removing a node again is O(1).
78 * drm_mm supports a few features: Alignment and range restrictions can be
79 * supplied. Further more every &drm_mm_node has a color value (which is just an
80 * opaqua unsigned long) which in conjunction with a driver callback can be used
81 * to implement sophisticated placement restrictions. The i915 DRM driver uses
82 * this to implement guard pages between incompatible caching domains in the
85 * Finally iteration helpers to walk all nodes and all holes are provided as are
86 * some basic allocator dumpers for debugging.
89 static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
93 enum drm_mm_search_flags flags);
94 static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
100 enum drm_mm_search_flags flags);
102 static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
103 struct drm_mm_node *node,
104 unsigned long size, unsigned alignment,
107 struct drm_mm *mm = hole_node->mm;
108 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
109 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
110 unsigned long adj_start = hole_start;
111 unsigned long adj_end = hole_end;
113 BUG_ON(node->allocated);
115 if (mm->color_adjust)
116 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
119 unsigned tmp = adj_start % alignment;
121 adj_start += alignment - tmp;
124 if (adj_start == hole_start) {
125 hole_node->hole_follows = 0;
126 list_del(&hole_node->hole_stack);
129 node->start = adj_start;
135 INIT_LIST_HEAD(&node->hole_stack);
136 list_add(&node->node_list, &hole_node->node_list);
138 BUG_ON(node->start + node->size > adj_end);
140 node->hole_follows = 0;
141 if (__drm_mm_hole_node_start(node) < hole_end) {
142 list_add(&node->hole_stack, &mm->hole_stack);
143 node->hole_follows = 1;
148 * drm_mm_reserve_node - insert an pre-initialized node
149 * @mm: drm_mm allocator to insert @node into
150 * @node: drm_mm_node to insert
152 * This functions inserts an already set-up drm_mm_node into the allocator,
153 * meaning that start, size and color must be set by the caller. This is useful
154 * to initialize the allocator with preallocated objects which must be set-up
155 * before the range allocator can be set-up, e.g. when taking over a firmware
159 * 0 on success, -ENOSPC if there's no hole where @node is.
161 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
163 struct drm_mm_node *hole;
164 unsigned long end = node->start + node->size;
165 unsigned long hole_start;
166 unsigned long hole_end;
168 BUG_ON(node == NULL);
170 /* Find the relevant hole to add our node to */
171 drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
172 if (hole_start > node->start || hole_end < end)
178 INIT_LIST_HEAD(&node->hole_stack);
179 list_add(&node->node_list, &hole->node_list);
181 if (node->start == hole_start) {
182 hole->hole_follows = 0;
183 list_del_init(&hole->hole_stack);
186 node->hole_follows = 0;
187 if (end != hole_end) {
188 list_add(&node->hole_stack, &mm->hole_stack);
189 node->hole_follows = 1;
195 WARN(1, "no hole found for node 0x%lx + 0x%lx\n",
196 node->start, node->size);
199 EXPORT_SYMBOL(drm_mm_reserve_node);
202 * drm_mm_insert_node_generic - search for space and insert @node
203 * @mm: drm_mm to allocate from
204 * @node: preallocate node to insert
205 * @size: size of the allocation
206 * @alignment: alignment of the allocation
207 * @color: opaque tag value to use for this node
208 * @flags: flags to fine-tune the allocation
210 * The preallocated node must be cleared to 0.
213 * 0 on success, -ENOSPC if there's no suitable hole.
215 int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
216 unsigned long size, unsigned alignment,
218 enum drm_mm_search_flags flags)
220 struct drm_mm_node *hole_node;
222 hole_node = drm_mm_search_free_generic(mm, size, alignment,
227 drm_mm_insert_helper(hole_node, node, size, alignment, color);
230 EXPORT_SYMBOL(drm_mm_insert_node_generic);
232 static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
233 struct drm_mm_node *node,
234 unsigned long size, unsigned alignment,
236 unsigned long start, unsigned long end)
238 struct drm_mm *mm = hole_node->mm;
239 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
240 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
241 unsigned long adj_start = hole_start;
242 unsigned long adj_end = hole_end;
244 BUG_ON(!hole_node->hole_follows || node->allocated);
246 if (adj_start < start)
251 if (mm->color_adjust)
252 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
255 unsigned tmp = adj_start % alignment;
257 adj_start += alignment - tmp;
260 if (adj_start == hole_start) {
261 hole_node->hole_follows = 0;
262 list_del(&hole_node->hole_stack);
265 node->start = adj_start;
271 INIT_LIST_HEAD(&node->hole_stack);
272 list_add(&node->node_list, &hole_node->node_list);
274 BUG_ON(node->start + node->size > adj_end);
275 BUG_ON(node->start + node->size > end);
277 node->hole_follows = 0;
278 if (__drm_mm_hole_node_start(node) < hole_end) {
279 list_add(&node->hole_stack, &mm->hole_stack);
280 node->hole_follows = 1;
285 * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node
286 * @mm: drm_mm to allocate from
287 * @node: preallocate node to insert
288 * @size: size of the allocation
289 * @alignment: alignment of the allocation
290 * @color: opaque tag value to use for this node
291 * @start: start of the allowed range for this node
292 * @end: end of the allowed range for this node
293 * @flags: flags to fine-tune the allocation
295 * The preallocated node must be cleared to 0.
298 * 0 on success, -ENOSPC if there's no suitable hole.
300 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
301 unsigned long size, unsigned alignment, unsigned long color,
302 unsigned long start, unsigned long end,
303 enum drm_mm_search_flags flags)
305 struct drm_mm_node *hole_node;
307 hole_node = drm_mm_search_free_in_range_generic(mm,
308 size, alignment, color,
313 drm_mm_insert_helper_range(hole_node, node,
314 size, alignment, color,
318 EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
321 * drm_mm_remove_node - Remove a memory node from the allocator.
322 * @node: drm_mm_node to remove
324 * This just removes a node from its drm_mm allocator. The node does not need to
325 * be cleared again before it can be re-inserted into this or any other drm_mm
326 * allocator. It is a bug to call this function on a un-allocated node.
328 void drm_mm_remove_node(struct drm_mm_node *node)
330 struct drm_mm *mm = node->mm;
331 struct drm_mm_node *prev_node;
333 if (WARN_ON(!node->allocated))
336 BUG_ON(node->scanned_block || node->scanned_prev_free
337 || node->scanned_next_free);
340 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
342 if (node->hole_follows) {
343 BUG_ON(__drm_mm_hole_node_start(node) ==
344 __drm_mm_hole_node_end(node));
345 list_del(&node->hole_stack);
347 BUG_ON(__drm_mm_hole_node_start(node) !=
348 __drm_mm_hole_node_end(node));
351 if (!prev_node->hole_follows) {
352 prev_node->hole_follows = 1;
353 list_add(&prev_node->hole_stack, &mm->hole_stack);
355 list_move(&prev_node->hole_stack, &mm->hole_stack);
357 list_del(&node->node_list);
360 EXPORT_SYMBOL(drm_mm_remove_node);
362 static int check_free_hole(unsigned long start, unsigned long end,
363 unsigned long size, unsigned alignment)
365 if (end - start < size)
369 unsigned tmp = start % alignment;
371 start += alignment - tmp;
374 return end >= start + size;
377 static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
381 enum drm_mm_search_flags flags)
383 struct drm_mm_node *entry;
384 struct drm_mm_node *best;
385 unsigned long adj_start;
386 unsigned long adj_end;
387 unsigned long best_size;
389 BUG_ON(mm->scanned_blocks);
394 drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
395 if (mm->color_adjust) {
396 mm->color_adjust(entry, color, &adj_start, &adj_end);
397 if (adj_end <= adj_start)
401 if (!check_free_hole(adj_start, adj_end, size, alignment))
404 if (!(flags & DRM_MM_SEARCH_BEST))
407 if (entry->size < best_size) {
409 best_size = entry->size;
416 static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
422 enum drm_mm_search_flags flags)
424 struct drm_mm_node *entry;
425 struct drm_mm_node *best;
426 unsigned long adj_start;
427 unsigned long adj_end;
428 unsigned long best_size;
430 BUG_ON(mm->scanned_blocks);
435 drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
436 if (adj_start < start)
441 if (mm->color_adjust) {
442 mm->color_adjust(entry, color, &adj_start, &adj_end);
443 if (adj_end <= adj_start)
447 if (!check_free_hole(adj_start, adj_end, size, alignment))
450 if (!(flags & DRM_MM_SEARCH_BEST))
453 if (entry->size < best_size) {
455 best_size = entry->size;
463 * drm_mm_replace_node - move an allocation from @old to @new
464 * @old: drm_mm_node to remove from the allocator
465 * @new: drm_mm_node which should inherit @old's allocation
467 * This is useful for when drivers embed the drm_mm_node structure and hence
468 * can't move allocations by reassigning pointers. It's a combination of remove
469 * and insert with the guarantee that the allocation start will match.
471 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
473 list_replace(&old->node_list, &new->node_list);
474 list_replace(&old->hole_stack, &new->hole_stack);
475 new->hole_follows = old->hole_follows;
477 new->start = old->start;
478 new->size = old->size;
479 new->color = old->color;
484 EXPORT_SYMBOL(drm_mm_replace_node);
487 * DOC: lru scan roaster
489 * Very often GPUs need to have continuous allocations for a given object. When
490 * evicting objects to make space for a new one it is therefore not most
491 * efficient when we simply start to select all objects from the tail of an LRU
492 * until there's a suitable hole: Especially for big objects or nodes that
493 * otherwise have special allocation constraints there's a good chance we evict
494 * lots of (smaller) objects unecessarily.
496 * The DRM range allocator supports this use-case through the scanning
497 * interfaces. First a scan operation needs to be initialized with
498 * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds
499 * objects to the roaster (probably by walking an LRU list, but this can be
500 * freely implemented) until a suitable hole is found or there's no further
503 * The the driver must walk through all objects again in exactly the reverse
504 * order to restore the allocator state. Note that while the allocator is used
505 * in the scan mode no other operation is allowed.
507 * Finally the driver evicts all objects selected in the scan. Adding and
508 * removing an object is O(1), and since freeing a node is also O(1) the overall
509 * complexity is O(scanned_objects). So like the free stack which needs to be
510 * walked before a scan operation even begins this is linear in the number of
511 * objects. It doesn't seem to hurt badly.
515 * drm_mm_init_scan - initialize lru scanning
516 * @mm: drm_mm to scan
517 * @size: size of the allocation
518 * @alignment: alignment of the allocation
519 * @color: opaque tag value to use for the allocation
521 * This simply sets up the scanning routines with the parameters for the desired
522 * hole. Note that there's no need to specify allocation flags, since they only
523 * change the place a node is allocated from within a suitable hole.
526 * As long as the scan list is non-empty, no other operations than
527 * adding/removing nodes to/from the scan list are allowed.
529 void drm_mm_init_scan(struct drm_mm *mm,
534 mm->scan_color = color;
535 mm->scan_alignment = alignment;
536 mm->scan_size = size;
537 mm->scanned_blocks = 0;
538 mm->scan_hit_start = 0;
539 mm->scan_hit_end = 0;
540 mm->scan_check_range = 0;
541 mm->prev_scanned_node = NULL;
543 EXPORT_SYMBOL(drm_mm_init_scan);
546 * drm_mm_init_scan - initialize range-restricted lru scanning
547 * @mm: drm_mm to scan
548 * @size: size of the allocation
549 * @alignment: alignment of the allocation
550 * @color: opaque tag value to use for the allocation
551 * @start: start of the allowed range for the allocation
552 * @end: end of the allowed range for the allocation
554 * This simply sets up the scanning routines with the parameters for the desired
555 * hole. Note that there's no need to specify allocation flags, since they only
556 * change the place a node is allocated from within a suitable hole.
559 * As long as the scan list is non-empty, no other operations than
560 * adding/removing nodes to/from the scan list are allowed.
562 void drm_mm_init_scan_with_range(struct drm_mm *mm,
569 mm->scan_color = color;
570 mm->scan_alignment = alignment;
571 mm->scan_size = size;
572 mm->scanned_blocks = 0;
573 mm->scan_hit_start = 0;
574 mm->scan_hit_end = 0;
575 mm->scan_start = start;
577 mm->scan_check_range = 1;
578 mm->prev_scanned_node = NULL;
580 EXPORT_SYMBOL(drm_mm_init_scan_with_range);
583 * drm_mm_scan_add_block - add a node to the scan list
584 * @node: drm_mm_node to add
586 * Add a node to the scan list that might be freed to make space for the desired
590 * True if a hole has been found, false otherwise.
592 bool drm_mm_scan_add_block(struct drm_mm_node *node)
594 struct drm_mm *mm = node->mm;
595 struct drm_mm_node *prev_node;
596 unsigned long hole_start, hole_end;
597 unsigned long adj_start, adj_end;
599 mm->scanned_blocks++;
601 BUG_ON(node->scanned_block);
602 node->scanned_block = 1;
604 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
607 node->scanned_preceeds_hole = prev_node->hole_follows;
608 prev_node->hole_follows = 1;
609 list_del(&node->node_list);
610 node->node_list.prev = &prev_node->node_list;
611 node->node_list.next = &mm->prev_scanned_node->node_list;
612 mm->prev_scanned_node = node;
614 adj_start = hole_start = drm_mm_hole_node_start(prev_node);
615 adj_end = hole_end = drm_mm_hole_node_end(prev_node);
617 if (mm->scan_check_range) {
618 if (adj_start < mm->scan_start)
619 adj_start = mm->scan_start;
620 if (adj_end > mm->scan_end)
621 adj_end = mm->scan_end;
624 if (mm->color_adjust)
625 mm->color_adjust(prev_node, mm->scan_color,
626 &adj_start, &adj_end);
628 if (check_free_hole(adj_start, adj_end,
629 mm->scan_size, mm->scan_alignment)) {
630 mm->scan_hit_start = hole_start;
631 mm->scan_hit_end = hole_end;
637 EXPORT_SYMBOL(drm_mm_scan_add_block);
640 * drm_mm_scan_remove_block - remove a node from the scan list
641 * @node: drm_mm_node to remove
643 * Nodes _must_ be removed in the exact same order from the scan list as they
644 * have been added, otherwise the internal state of the memory manager will be
647 * When the scan list is empty, the selected memory nodes can be freed. An
648 * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then
649 * return the just freed block (because its at the top of the free_stack list).
652 * True if this block should be evicted, false otherwise. Will always
653 * return false when no hole has been found.
655 bool drm_mm_scan_remove_block(struct drm_mm_node *node)
657 struct drm_mm *mm = node->mm;
658 struct drm_mm_node *prev_node;
660 mm->scanned_blocks--;
662 BUG_ON(!node->scanned_block);
663 node->scanned_block = 0;
665 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
668 prev_node->hole_follows = node->scanned_preceeds_hole;
669 list_add(&node->node_list, &prev_node->node_list);
671 return (drm_mm_hole_node_end(node) > mm->scan_hit_start &&
672 node->start < mm->scan_hit_end);
674 EXPORT_SYMBOL(drm_mm_scan_remove_block);
677 * drm_mm_clean - checks whether an allocator is clean
678 * @mm: drm_mm allocator to check
681 * True if the allocator is completely free, false if there's still a node
684 bool drm_mm_clean(struct drm_mm * mm)
686 struct list_head *head = &mm->head_node.node_list;
688 return (head->next->next == head);
690 EXPORT_SYMBOL(drm_mm_clean);
693 * drm_mm_init - initialize a drm-mm allocator
694 * @mm: the drm_mm structure to initialize
695 * @start: start of the range managed by @mm
696 * @size: end of the range managed by @mm
698 * Note that @mm must be cleared to 0 before calling this function.
700 void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
702 INIT_LIST_HEAD(&mm->hole_stack);
703 mm->scanned_blocks = 0;
705 /* Clever trick to avoid a special case in the free hole tracking. */
706 INIT_LIST_HEAD(&mm->head_node.node_list);
707 INIT_LIST_HEAD(&mm->head_node.hole_stack);
708 mm->head_node.hole_follows = 1;
709 mm->head_node.scanned_block = 0;
710 mm->head_node.scanned_prev_free = 0;
711 mm->head_node.scanned_next_free = 0;
712 mm->head_node.mm = mm;
713 mm->head_node.start = start + size;
714 mm->head_node.size = start - mm->head_node.start;
715 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
717 mm->color_adjust = NULL;
719 EXPORT_SYMBOL(drm_mm_init);
722 * drm_mm_takedown - clean up a drm_mm allocator
723 * @mm: drm_mm allocator to clean up
725 * Note that it is a bug to call this function on an allocator which is not
728 void drm_mm_takedown(struct drm_mm * mm)
730 WARN(!list_empty(&mm->head_node.node_list),
731 "Memory manager not clean during takedown.\n");
733 EXPORT_SYMBOL(drm_mm_takedown);
735 static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry,
738 unsigned long hole_start, hole_end, hole_size;
740 if (entry->hole_follows) {
741 hole_start = drm_mm_hole_node_start(entry);
742 hole_end = drm_mm_hole_node_end(entry);
743 hole_size = hole_end - hole_start;
744 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
745 prefix, hole_start, hole_end,
754 * drm_mm_debug_table - dump allocator state to dmesg
755 * @mm: drm_mm allocator to dump
756 * @prefix: prefix to use for dumping to dmesg
758 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
760 struct drm_mm_node *entry;
761 unsigned long total_used = 0, total_free = 0, total = 0;
763 total_free += drm_mm_debug_hole(&mm->head_node, prefix);
765 drm_mm_for_each_node(entry, mm) {
766 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
767 prefix, entry->start, entry->start + entry->size,
769 total_used += entry->size;
770 total_free += drm_mm_debug_hole(entry, prefix);
772 total = total_free + total_used;
774 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
775 total_used, total_free);
777 EXPORT_SYMBOL(drm_mm_debug_table);
779 #if defined(CONFIG_DEBUG_FS)
780 static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
782 unsigned long hole_start, hole_end, hole_size;
784 if (entry->hole_follows) {
785 hole_start = drm_mm_hole_node_start(entry);
786 hole_end = drm_mm_hole_node_end(entry);
787 hole_size = hole_end - hole_start;
788 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
789 hole_start, hole_end, hole_size);
797 * drm_mm_dump_table - dump allocator state to a seq_file
798 * @m: seq_file to dump to
799 * @mm: drm_mm allocator to dump
801 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
803 struct drm_mm_node *entry;
804 unsigned long total_used = 0, total_free = 0, total = 0;
806 total_free += drm_mm_dump_hole(m, &mm->head_node);
808 drm_mm_for_each_node(entry, mm) {
809 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
810 entry->start, entry->start + entry->size,
812 total_used += entry->size;
813 total_free += drm_mm_dump_hole(m, entry);
815 total = total_free + total_used;
817 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
820 EXPORT_SYMBOL(drm_mm_dump_table);