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>
50 #define MM_UNUSED_TARGET 4
52 static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
54 struct drm_mm_node *child;
57 child = kzalloc(sizeof(*child), GFP_ATOMIC);
59 child = kzalloc(sizeof(*child), GFP_KERNEL);
61 if (unlikely(child == NULL)) {
62 spin_lock(&mm->unused_lock);
63 if (list_empty(&mm->unused_nodes))
67 list_entry(mm->unused_nodes.next,
68 struct drm_mm_node, node_list);
69 list_del(&child->node_list);
72 spin_unlock(&mm->unused_lock);
77 /* drm_mm_pre_get() - pre allocate drm_mm_node structure
78 * drm_mm: memory manager struct we are pre-allocating for
80 * Returns 0 on success or -ENOMEM if allocation fails.
82 int drm_mm_pre_get(struct drm_mm *mm)
84 struct drm_mm_node *node;
86 spin_lock(&mm->unused_lock);
87 while (mm->num_unused < MM_UNUSED_TARGET) {
88 spin_unlock(&mm->unused_lock);
89 node = kzalloc(sizeof(*node), GFP_KERNEL);
90 spin_lock(&mm->unused_lock);
92 if (unlikely(node == NULL)) {
93 int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
94 spin_unlock(&mm->unused_lock);
98 list_add_tail(&node->node_list, &mm->unused_nodes);
100 spin_unlock(&mm->unused_lock);
103 EXPORT_SYMBOL(drm_mm_pre_get);
105 static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
107 return hole_node->start + hole_node->size;
110 static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
112 struct drm_mm_node *next_node =
113 list_entry(hole_node->node_list.next, struct drm_mm_node,
116 return next_node->start;
119 static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
120 struct drm_mm_node *node,
121 unsigned long size, unsigned alignment,
124 struct drm_mm *mm = hole_node->mm;
125 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
126 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
127 unsigned long adj_start = hole_start;
128 unsigned long adj_end = hole_end;
130 BUG_ON(!hole_node->hole_follows || node->allocated);
132 if (mm->color_adjust)
133 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
136 unsigned tmp = adj_start % alignment;
138 adj_start += alignment - tmp;
141 if (adj_start == hole_start) {
142 hole_node->hole_follows = 0;
143 list_del(&hole_node->hole_stack);
146 node->start = adj_start;
152 INIT_LIST_HEAD(&node->hole_stack);
153 list_add(&node->node_list, &hole_node->node_list);
155 BUG_ON(node->start + node->size > adj_end);
157 node->hole_follows = 0;
158 if (node->start + node->size < hole_end) {
159 list_add(&node->hole_stack, &mm->hole_stack);
160 node->hole_follows = 1;
164 struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
170 struct drm_mm_node *node;
172 node = drm_mm_kmalloc(hole_node->mm, atomic);
173 if (unlikely(node == NULL))
176 drm_mm_insert_helper(hole_node, node, size, alignment, color);
180 EXPORT_SYMBOL(drm_mm_get_block_generic);
183 * Search for free space and insert a preallocated memory node. Returns
184 * -ENOSPC if no suitable free area is available. The preallocated memory node
187 int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
188 unsigned long size, unsigned alignment,
191 struct drm_mm_node *hole_node;
193 hole_node = drm_mm_search_free_generic(mm, size, alignment,
198 drm_mm_insert_helper(hole_node, node, size, alignment, color);
201 EXPORT_SYMBOL(drm_mm_insert_node_generic);
203 int drm_mm_insert_node(struct drm_mm *mm, struct drm_mm_node *node,
204 unsigned long size, unsigned alignment)
206 return drm_mm_insert_node_generic(mm, node, size, alignment, 0);
208 EXPORT_SYMBOL(drm_mm_insert_node);
210 static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
211 struct drm_mm_node *node,
212 unsigned long size, unsigned alignment,
214 unsigned long start, unsigned long end)
216 struct drm_mm *mm = hole_node->mm;
217 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
218 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
219 unsigned long adj_start = hole_start;
220 unsigned long adj_end = hole_end;
222 BUG_ON(!hole_node->hole_follows || node->allocated);
224 if (mm->color_adjust)
225 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
227 if (adj_start < start)
231 unsigned tmp = adj_start % alignment;
233 adj_start += alignment - tmp;
236 if (adj_start == hole_start) {
237 hole_node->hole_follows = 0;
238 list_del(&hole_node->hole_stack);
241 node->start = adj_start;
247 INIT_LIST_HEAD(&node->hole_stack);
248 list_add(&node->node_list, &hole_node->node_list);
250 BUG_ON(node->start + node->size > adj_end);
251 BUG_ON(node->start + node->size > end);
253 node->hole_follows = 0;
254 if (node->start + node->size < hole_end) {
255 list_add(&node->hole_stack, &mm->hole_stack);
256 node->hole_follows = 1;
260 struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
268 struct drm_mm_node *node;
270 node = drm_mm_kmalloc(hole_node->mm, atomic);
271 if (unlikely(node == NULL))
274 drm_mm_insert_helper_range(hole_node, node, size, alignment, color,
279 EXPORT_SYMBOL(drm_mm_get_block_range_generic);
282 * Search for free space and insert a preallocated memory node. Returns
283 * -ENOSPC if no suitable free area is available. This is for range
284 * restricted allocations. The preallocated memory node must be cleared.
286 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
287 unsigned long size, unsigned alignment, unsigned long color,
288 unsigned long start, unsigned long end)
290 struct drm_mm_node *hole_node;
292 hole_node = drm_mm_search_free_in_range_generic(mm,
293 size, alignment, color,
298 drm_mm_insert_helper_range(hole_node, node,
299 size, alignment, color,
303 EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
305 int drm_mm_insert_node_in_range(struct drm_mm *mm, struct drm_mm_node *node,
306 unsigned long size, unsigned alignment,
307 unsigned long start, unsigned long end)
309 return drm_mm_insert_node_in_range_generic(mm, node, size, alignment, 0, start, end);
311 EXPORT_SYMBOL(drm_mm_insert_node_in_range);
314 * Remove a memory node from the allocator.
316 void drm_mm_remove_node(struct drm_mm_node *node)
318 struct drm_mm *mm = node->mm;
319 struct drm_mm_node *prev_node;
321 BUG_ON(node->scanned_block || node->scanned_prev_free
322 || node->scanned_next_free);
325 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
327 if (node->hole_follows) {
328 BUG_ON(drm_mm_hole_node_start(node)
329 == drm_mm_hole_node_end(node));
330 list_del(&node->hole_stack);
332 BUG_ON(drm_mm_hole_node_start(node)
333 != drm_mm_hole_node_end(node));
335 if (!prev_node->hole_follows) {
336 prev_node->hole_follows = 1;
337 list_add(&prev_node->hole_stack, &mm->hole_stack);
339 list_move(&prev_node->hole_stack, &mm->hole_stack);
341 list_del(&node->node_list);
344 EXPORT_SYMBOL(drm_mm_remove_node);
347 * Remove a memory node from the allocator and free the allocated struct
348 * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
349 * drm_mm_get_block functions.
351 void drm_mm_put_block(struct drm_mm_node *node)
354 struct drm_mm *mm = node->mm;
356 drm_mm_remove_node(node);
358 spin_lock(&mm->unused_lock);
359 if (mm->num_unused < MM_UNUSED_TARGET) {
360 list_add(&node->node_list, &mm->unused_nodes);
364 spin_unlock(&mm->unused_lock);
366 EXPORT_SYMBOL(drm_mm_put_block);
368 static int check_free_hole(unsigned long start, unsigned long end,
369 unsigned long size, unsigned alignment)
371 if (end - start < size)
375 unsigned tmp = start % alignment;
377 start += alignment - tmp;
380 return end >= start + size;
383 struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
389 struct drm_mm_node *entry;
390 struct drm_mm_node *best;
391 unsigned long best_size;
393 BUG_ON(mm->scanned_blocks);
398 list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
399 unsigned long adj_start = drm_mm_hole_node_start(entry);
400 unsigned long adj_end = drm_mm_hole_node_end(entry);
402 if (mm->color_adjust) {
403 mm->color_adjust(entry, color, &adj_start, &adj_end);
404 if (adj_end <= adj_start)
408 BUG_ON(!entry->hole_follows);
409 if (!check_free_hole(adj_start, adj_end, size, alignment))
415 if (entry->size < best_size) {
417 best_size = entry->size;
423 EXPORT_SYMBOL(drm_mm_search_free_generic);
425 struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
433 struct drm_mm_node *entry;
434 struct drm_mm_node *best;
435 unsigned long best_size;
437 BUG_ON(mm->scanned_blocks);
442 list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
443 unsigned long adj_start = drm_mm_hole_node_start(entry) < start ?
444 start : drm_mm_hole_node_start(entry);
445 unsigned long adj_end = drm_mm_hole_node_end(entry) > end ?
446 end : drm_mm_hole_node_end(entry);
448 BUG_ON(!entry->hole_follows);
450 if (mm->color_adjust) {
451 mm->color_adjust(entry, color, &adj_start, &adj_end);
452 if (adj_end <= adj_start)
456 if (!check_free_hole(adj_start, adj_end, size, alignment))
462 if (entry->size < best_size) {
464 best_size = entry->size;
470 EXPORT_SYMBOL(drm_mm_search_free_in_range_generic);
473 * Moves an allocation. To be used with embedded struct drm_mm_node.
475 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
477 list_replace(&old->node_list, &new->node_list);
478 list_replace(&old->hole_stack, &new->hole_stack);
479 new->hole_follows = old->hole_follows;
481 new->start = old->start;
482 new->size = old->size;
483 new->color = old->color;
488 EXPORT_SYMBOL(drm_mm_replace_node);
491 * Initializa lru scanning.
493 * This simply sets up the scanning routines with the parameters for the desired
496 * Warning: As long as the scan list is non-empty, no other operations than
497 * adding/removing nodes to/from the scan list are allowed.
499 void drm_mm_init_scan(struct drm_mm *mm,
504 mm->scan_color = color;
505 mm->scan_alignment = alignment;
506 mm->scan_size = size;
507 mm->scanned_blocks = 0;
508 mm->scan_hit_start = 0;
509 mm->scan_hit_size = 0;
510 mm->scan_check_range = 0;
511 mm->prev_scanned_node = NULL;
513 EXPORT_SYMBOL(drm_mm_init_scan);
516 * Initializa lru scanning.
518 * This simply sets up the scanning routines with the parameters for the desired
519 * hole. This version is for range-restricted scans.
521 * Warning: As long as the scan list is non-empty, no other operations than
522 * adding/removing nodes to/from the scan list are allowed.
524 void drm_mm_init_scan_with_range(struct drm_mm *mm,
531 mm->scan_color = color;
532 mm->scan_alignment = alignment;
533 mm->scan_size = size;
534 mm->scanned_blocks = 0;
535 mm->scan_hit_start = 0;
536 mm->scan_hit_size = 0;
537 mm->scan_start = start;
539 mm->scan_check_range = 1;
540 mm->prev_scanned_node = NULL;
542 EXPORT_SYMBOL(drm_mm_init_scan_with_range);
545 * Add a node to the scan list that might be freed to make space for the desired
548 * Returns non-zero, if a hole has been found, zero otherwise.
550 int drm_mm_scan_add_block(struct drm_mm_node *node)
552 struct drm_mm *mm = node->mm;
553 struct drm_mm_node *prev_node;
554 unsigned long hole_start, hole_end;
555 unsigned long adj_start;
556 unsigned long adj_end;
558 mm->scanned_blocks++;
560 BUG_ON(node->scanned_block);
561 node->scanned_block = 1;
563 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
566 node->scanned_preceeds_hole = prev_node->hole_follows;
567 prev_node->hole_follows = 1;
568 list_del(&node->node_list);
569 node->node_list.prev = &prev_node->node_list;
570 node->node_list.next = &mm->prev_scanned_node->node_list;
571 mm->prev_scanned_node = node;
573 hole_start = drm_mm_hole_node_start(prev_node);
574 hole_end = drm_mm_hole_node_end(prev_node);
576 adj_start = hole_start;
579 if (mm->color_adjust)
580 mm->color_adjust(prev_node, mm->scan_color, &adj_start, &adj_end);
582 if (mm->scan_check_range) {
583 if (adj_start < mm->scan_start)
584 adj_start = mm->scan_start;
585 if (adj_end > mm->scan_end)
586 adj_end = mm->scan_end;
589 if (check_free_hole(adj_start, adj_end,
590 mm->scan_size, mm->scan_alignment)) {
591 mm->scan_hit_start = hole_start;
592 mm->scan_hit_size = hole_end;
599 EXPORT_SYMBOL(drm_mm_scan_add_block);
602 * Remove a node from the scan list.
604 * Nodes _must_ be removed in the exact same order from the scan list as they
605 * have been added, otherwise the internal state of the memory manager will be
608 * When the scan list is empty, the selected memory nodes can be freed. An
609 * immediately following drm_mm_search_free with best_match = 0 will then return
610 * the just freed block (because its at the top of the free_stack list).
612 * Returns one if this block should be evicted, zero otherwise. Will always
613 * return zero when no hole has been found.
615 int drm_mm_scan_remove_block(struct drm_mm_node *node)
617 struct drm_mm *mm = node->mm;
618 struct drm_mm_node *prev_node;
620 mm->scanned_blocks--;
622 BUG_ON(!node->scanned_block);
623 node->scanned_block = 0;
625 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
628 prev_node->hole_follows = node->scanned_preceeds_hole;
629 INIT_LIST_HEAD(&node->node_list);
630 list_add(&node->node_list, &prev_node->node_list);
632 /* Only need to check for containement because start&size for the
633 * complete resulting free block (not just the desired part) is
635 if (node->start >= mm->scan_hit_start &&
636 node->start + node->size
637 <= mm->scan_hit_start + mm->scan_hit_size) {
643 EXPORT_SYMBOL(drm_mm_scan_remove_block);
645 int drm_mm_clean(struct drm_mm * mm)
647 struct list_head *head = &mm->head_node.node_list;
649 return (head->next->next == head);
651 EXPORT_SYMBOL(drm_mm_clean);
653 int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
655 INIT_LIST_HEAD(&mm->hole_stack);
656 INIT_LIST_HEAD(&mm->unused_nodes);
658 mm->scanned_blocks = 0;
659 spin_lock_init(&mm->unused_lock);
661 /* Clever trick to avoid a special case in the free hole tracking. */
662 INIT_LIST_HEAD(&mm->head_node.node_list);
663 INIT_LIST_HEAD(&mm->head_node.hole_stack);
664 mm->head_node.hole_follows = 1;
665 mm->head_node.scanned_block = 0;
666 mm->head_node.scanned_prev_free = 0;
667 mm->head_node.scanned_next_free = 0;
668 mm->head_node.mm = mm;
669 mm->head_node.start = start + size;
670 mm->head_node.size = start - mm->head_node.start;
671 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
673 mm->color_adjust = NULL;
677 EXPORT_SYMBOL(drm_mm_init);
679 void drm_mm_takedown(struct drm_mm * mm)
681 struct drm_mm_node *entry, *next;
683 if (!list_empty(&mm->head_node.node_list)) {
684 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
688 spin_lock(&mm->unused_lock);
689 list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
690 list_del(&entry->node_list);
694 spin_unlock(&mm->unused_lock);
696 BUG_ON(mm->num_unused != 0);
698 EXPORT_SYMBOL(drm_mm_takedown);
700 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
702 struct drm_mm_node *entry;
703 unsigned long total_used = 0, total_free = 0, total = 0;
704 unsigned long hole_start, hole_end, hole_size;
706 hole_start = drm_mm_hole_node_start(&mm->head_node);
707 hole_end = drm_mm_hole_node_end(&mm->head_node);
708 hole_size = hole_end - hole_start;
710 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
711 prefix, hole_start, hole_end,
713 total_free += hole_size;
715 drm_mm_for_each_node(entry, mm) {
716 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
717 prefix, entry->start, entry->start + entry->size,
719 total_used += entry->size;
721 if (entry->hole_follows) {
722 hole_start = drm_mm_hole_node_start(entry);
723 hole_end = drm_mm_hole_node_end(entry);
724 hole_size = hole_end - hole_start;
725 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
726 prefix, hole_start, hole_end,
728 total_free += hole_size;
731 total = total_free + total_used;
733 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
734 total_used, total_free);
736 EXPORT_SYMBOL(drm_mm_debug_table);
738 #if defined(CONFIG_DEBUG_FS)
739 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
741 struct drm_mm_node *entry;
742 unsigned long total_used = 0, total_free = 0, total = 0;
743 unsigned long hole_start, hole_end, hole_size;
745 hole_start = drm_mm_hole_node_start(&mm->head_node);
746 hole_end = drm_mm_hole_node_end(&mm->head_node);
747 hole_size = hole_end - hole_start;
749 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
750 hole_start, hole_end, hole_size);
751 total_free += hole_size;
753 drm_mm_for_each_node(entry, mm) {
754 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
755 entry->start, entry->start + entry->size,
757 total_used += entry->size;
758 if (entry->hole_follows) {
759 hole_start = drm_mm_hole_node_start(entry);
760 hole_end = drm_mm_hole_node_end(entry);
761 hole_size = hole_end - hole_start;
762 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
763 hole_start, hole_end, hole_size);
764 total_free += hole_size;
767 total = total_free + total_used;
769 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
772 EXPORT_SYMBOL(drm_mm_dump_table);