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 (adj_start < start)
229 if (mm->color_adjust)
230 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
233 unsigned tmp = adj_start % alignment;
235 adj_start += alignment - tmp;
238 if (adj_start == hole_start) {
239 hole_node->hole_follows = 0;
240 list_del(&hole_node->hole_stack);
243 node->start = adj_start;
249 INIT_LIST_HEAD(&node->hole_stack);
250 list_add(&node->node_list, &hole_node->node_list);
252 BUG_ON(node->start + node->size > adj_end);
253 BUG_ON(node->start + node->size > end);
255 node->hole_follows = 0;
256 if (node->start + node->size < hole_end) {
257 list_add(&node->hole_stack, &mm->hole_stack);
258 node->hole_follows = 1;
262 struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
270 struct drm_mm_node *node;
272 node = drm_mm_kmalloc(hole_node->mm, atomic);
273 if (unlikely(node == NULL))
276 drm_mm_insert_helper_range(hole_node, node, size, alignment, color,
281 EXPORT_SYMBOL(drm_mm_get_block_range_generic);
284 * Search for free space and insert a preallocated memory node. Returns
285 * -ENOSPC if no suitable free area is available. This is for range
286 * restricted allocations. The preallocated memory node must be cleared.
288 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
289 unsigned long size, unsigned alignment, unsigned long color,
290 unsigned long start, unsigned long end)
292 struct drm_mm_node *hole_node;
294 hole_node = drm_mm_search_free_in_range_generic(mm,
295 size, alignment, color,
300 drm_mm_insert_helper_range(hole_node, node,
301 size, alignment, color,
305 EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
307 int drm_mm_insert_node_in_range(struct drm_mm *mm, struct drm_mm_node *node,
308 unsigned long size, unsigned alignment,
309 unsigned long start, unsigned long end)
311 return drm_mm_insert_node_in_range_generic(mm, node, size, alignment, 0, start, end);
313 EXPORT_SYMBOL(drm_mm_insert_node_in_range);
316 * Remove a memory node from the allocator.
318 void drm_mm_remove_node(struct drm_mm_node *node)
320 struct drm_mm *mm = node->mm;
321 struct drm_mm_node *prev_node;
323 BUG_ON(node->scanned_block || node->scanned_prev_free
324 || node->scanned_next_free);
327 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
329 if (node->hole_follows) {
330 BUG_ON(drm_mm_hole_node_start(node)
331 == drm_mm_hole_node_end(node));
332 list_del(&node->hole_stack);
334 BUG_ON(drm_mm_hole_node_start(node)
335 != drm_mm_hole_node_end(node));
337 if (!prev_node->hole_follows) {
338 prev_node->hole_follows = 1;
339 list_add(&prev_node->hole_stack, &mm->hole_stack);
341 list_move(&prev_node->hole_stack, &mm->hole_stack);
343 list_del(&node->node_list);
346 EXPORT_SYMBOL(drm_mm_remove_node);
349 * Remove a memory node from the allocator and free the allocated struct
350 * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
351 * drm_mm_get_block functions.
353 void drm_mm_put_block(struct drm_mm_node *node)
356 struct drm_mm *mm = node->mm;
358 drm_mm_remove_node(node);
360 spin_lock(&mm->unused_lock);
361 if (mm->num_unused < MM_UNUSED_TARGET) {
362 list_add(&node->node_list, &mm->unused_nodes);
366 spin_unlock(&mm->unused_lock);
368 EXPORT_SYMBOL(drm_mm_put_block);
370 static int check_free_hole(unsigned long start, unsigned long end,
371 unsigned long size, unsigned alignment)
373 if (end - start < size)
377 unsigned tmp = start % alignment;
379 start += alignment - tmp;
382 return end >= start + size;
385 struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
391 struct drm_mm_node *entry;
392 struct drm_mm_node *best;
393 unsigned long best_size;
395 BUG_ON(mm->scanned_blocks);
400 list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
401 unsigned long adj_start = drm_mm_hole_node_start(entry);
402 unsigned long adj_end = drm_mm_hole_node_end(entry);
404 if (mm->color_adjust) {
405 mm->color_adjust(entry, color, &adj_start, &adj_end);
406 if (adj_end <= adj_start)
410 BUG_ON(!entry->hole_follows);
411 if (!check_free_hole(adj_start, adj_end, size, alignment))
417 if (entry->size < best_size) {
419 best_size = entry->size;
425 EXPORT_SYMBOL(drm_mm_search_free_generic);
427 struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
435 struct drm_mm_node *entry;
436 struct drm_mm_node *best;
437 unsigned long best_size;
439 BUG_ON(mm->scanned_blocks);
444 list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
445 unsigned long adj_start = drm_mm_hole_node_start(entry) < start ?
446 start : drm_mm_hole_node_start(entry);
447 unsigned long adj_end = drm_mm_hole_node_end(entry) > end ?
448 end : drm_mm_hole_node_end(entry);
450 BUG_ON(!entry->hole_follows);
452 if (mm->color_adjust) {
453 mm->color_adjust(entry, color, &adj_start, &adj_end);
454 if (adj_end <= adj_start)
458 if (!check_free_hole(adj_start, adj_end, size, alignment))
464 if (entry->size < best_size) {
466 best_size = entry->size;
472 EXPORT_SYMBOL(drm_mm_search_free_in_range_generic);
475 * Moves an allocation. To be used with embedded struct drm_mm_node.
477 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
479 list_replace(&old->node_list, &new->node_list);
480 list_replace(&old->hole_stack, &new->hole_stack);
481 new->hole_follows = old->hole_follows;
483 new->start = old->start;
484 new->size = old->size;
485 new->color = old->color;
490 EXPORT_SYMBOL(drm_mm_replace_node);
493 * Initializa lru scanning.
495 * This simply sets up the scanning routines with the parameters for the desired
498 * Warning: As long as the scan list is non-empty, no other operations than
499 * adding/removing nodes to/from the scan list are allowed.
501 void drm_mm_init_scan(struct drm_mm *mm,
506 mm->scan_color = color;
507 mm->scan_alignment = alignment;
508 mm->scan_size = size;
509 mm->scanned_blocks = 0;
510 mm->scan_hit_start = 0;
511 mm->scan_hit_end = 0;
512 mm->scan_check_range = 0;
513 mm->prev_scanned_node = NULL;
515 EXPORT_SYMBOL(drm_mm_init_scan);
518 * Initializa lru scanning.
520 * This simply sets up the scanning routines with the parameters for the desired
521 * hole. This version is for range-restricted scans.
523 * Warning: As long as the scan list is non-empty, no other operations than
524 * adding/removing nodes to/from the scan list are allowed.
526 void drm_mm_init_scan_with_range(struct drm_mm *mm,
533 mm->scan_color = color;
534 mm->scan_alignment = alignment;
535 mm->scan_size = size;
536 mm->scanned_blocks = 0;
537 mm->scan_hit_start = 0;
538 mm->scan_hit_end = 0;
539 mm->scan_start = start;
541 mm->scan_check_range = 1;
542 mm->prev_scanned_node = NULL;
544 EXPORT_SYMBOL(drm_mm_init_scan_with_range);
547 * Add a node to the scan list that might be freed to make space for the desired
550 * Returns non-zero, if a hole has been found, zero otherwise.
552 int drm_mm_scan_add_block(struct drm_mm_node *node)
554 struct drm_mm *mm = node->mm;
555 struct drm_mm_node *prev_node;
556 unsigned long hole_start, hole_end;
557 unsigned long adj_start, adj_end;
559 mm->scanned_blocks++;
561 BUG_ON(node->scanned_block);
562 node->scanned_block = 1;
564 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
567 node->scanned_preceeds_hole = prev_node->hole_follows;
568 prev_node->hole_follows = 1;
569 list_del(&node->node_list);
570 node->node_list.prev = &prev_node->node_list;
571 node->node_list.next = &mm->prev_scanned_node->node_list;
572 mm->prev_scanned_node = node;
574 adj_start = hole_start = drm_mm_hole_node_start(prev_node);
575 adj_end = hole_end = drm_mm_hole_node_end(prev_node);
577 if (mm->scan_check_range) {
578 if (adj_start < mm->scan_start)
579 adj_start = mm->scan_start;
580 if (adj_end > mm->scan_end)
581 adj_end = mm->scan_end;
584 if (mm->color_adjust)
585 mm->color_adjust(prev_node, mm->scan_color,
586 &adj_start, &adj_end);
588 if (check_free_hole(adj_start, adj_end,
589 mm->scan_size, mm->scan_alignment)) {
590 mm->scan_hit_start = hole_start;
591 mm->scan_hit_end = hole_end;
597 EXPORT_SYMBOL(drm_mm_scan_add_block);
600 * Remove a node from the scan list.
602 * Nodes _must_ be removed in the exact same order from the scan list as they
603 * have been added, otherwise the internal state of the memory manager will be
606 * When the scan list is empty, the selected memory nodes can be freed. An
607 * immediately following drm_mm_search_free with best_match = 0 will then return
608 * the just freed block (because its at the top of the free_stack list).
610 * Returns one if this block should be evicted, zero otherwise. Will always
611 * return zero when no hole has been found.
613 int drm_mm_scan_remove_block(struct drm_mm_node *node)
615 struct drm_mm *mm = node->mm;
616 struct drm_mm_node *prev_node;
618 mm->scanned_blocks--;
620 BUG_ON(!node->scanned_block);
621 node->scanned_block = 0;
623 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
626 prev_node->hole_follows = node->scanned_preceeds_hole;
627 list_add(&node->node_list, &prev_node->node_list);
629 return (drm_mm_hole_node_end(node) > mm->scan_hit_start &&
630 node->start < mm->scan_hit_end);
632 EXPORT_SYMBOL(drm_mm_scan_remove_block);
634 int drm_mm_clean(struct drm_mm * mm)
636 struct list_head *head = &mm->head_node.node_list;
638 return (head->next->next == head);
640 EXPORT_SYMBOL(drm_mm_clean);
642 int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
644 INIT_LIST_HEAD(&mm->hole_stack);
645 INIT_LIST_HEAD(&mm->unused_nodes);
647 mm->scanned_blocks = 0;
648 spin_lock_init(&mm->unused_lock);
650 /* Clever trick to avoid a special case in the free hole tracking. */
651 INIT_LIST_HEAD(&mm->head_node.node_list);
652 INIT_LIST_HEAD(&mm->head_node.hole_stack);
653 mm->head_node.hole_follows = 1;
654 mm->head_node.scanned_block = 0;
655 mm->head_node.scanned_prev_free = 0;
656 mm->head_node.scanned_next_free = 0;
657 mm->head_node.mm = mm;
658 mm->head_node.start = start + size;
659 mm->head_node.size = start - mm->head_node.start;
660 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
662 mm->color_adjust = NULL;
666 EXPORT_SYMBOL(drm_mm_init);
668 void drm_mm_takedown(struct drm_mm * mm)
670 struct drm_mm_node *entry, *next;
672 if (!list_empty(&mm->head_node.node_list)) {
673 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
677 spin_lock(&mm->unused_lock);
678 list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
679 list_del(&entry->node_list);
683 spin_unlock(&mm->unused_lock);
685 BUG_ON(mm->num_unused != 0);
687 EXPORT_SYMBOL(drm_mm_takedown);
689 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
691 struct drm_mm_node *entry;
692 unsigned long total_used = 0, total_free = 0, total = 0;
693 unsigned long hole_start, hole_end, hole_size;
695 hole_start = drm_mm_hole_node_start(&mm->head_node);
696 hole_end = drm_mm_hole_node_end(&mm->head_node);
697 hole_size = hole_end - hole_start;
699 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
700 prefix, hole_start, hole_end,
702 total_free += hole_size;
704 drm_mm_for_each_node(entry, mm) {
705 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
706 prefix, entry->start, entry->start + entry->size,
708 total_used += entry->size;
710 if (entry->hole_follows) {
711 hole_start = drm_mm_hole_node_start(entry);
712 hole_end = drm_mm_hole_node_end(entry);
713 hole_size = hole_end - hole_start;
714 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
715 prefix, hole_start, hole_end,
717 total_free += hole_size;
720 total = total_free + total_used;
722 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
723 total_used, total_free);
725 EXPORT_SYMBOL(drm_mm_debug_table);
727 #if defined(CONFIG_DEBUG_FS)
728 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
730 struct drm_mm_node *entry;
731 unsigned long total_used = 0, total_free = 0, total = 0;
732 unsigned long hole_start, hole_end, hole_size;
734 hole_start = drm_mm_hole_node_start(&mm->head_node);
735 hole_end = drm_mm_hole_node_end(&mm->head_node);
736 hole_size = hole_end - hole_start;
738 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
739 hole_start, hole_end, hole_size);
740 total_free += hole_size;
742 drm_mm_for_each_node(entry, mm) {
743 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
744 entry->start, entry->start + entry->size,
746 total_used += entry->size;
747 if (entry->hole_follows) {
748 hole_start = drm_mm_hole_node_start(entry);
749 hole_end = drm_mm_hole_node_end(entry);
750 hole_size = hole_end - hole_start;
751 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
752 hole_start, hole_end, hole_size);
753 total_free += hole_size;
756 total = total_free + total_used;
758 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
761 EXPORT_SYMBOL(drm_mm_dump_table);