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 void drm_mm_insert_helper(struct drm_mm_node *hole_node,
106 struct drm_mm_node *node,
107 unsigned long size, unsigned alignment,
110 struct drm_mm *mm = hole_node->mm;
111 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
112 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
113 unsigned long adj_start = hole_start;
114 unsigned long adj_end = hole_end;
116 BUG_ON(node->allocated);
118 if (mm->color_adjust)
119 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
122 unsigned tmp = adj_start % alignment;
124 adj_start += alignment - tmp;
127 if (adj_start == hole_start) {
128 hole_node->hole_follows = 0;
129 list_del(&hole_node->hole_stack);
132 node->start = adj_start;
138 INIT_LIST_HEAD(&node->hole_stack);
139 list_add(&node->node_list, &hole_node->node_list);
141 BUG_ON(node->start + node->size > adj_end);
143 node->hole_follows = 0;
144 if (__drm_mm_hole_node_start(node) < hole_end) {
145 list_add(&node->hole_stack, &mm->hole_stack);
146 node->hole_follows = 1;
150 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
152 struct drm_mm_node *hole;
153 unsigned long end = node->start + node->size;
154 unsigned long hole_start;
155 unsigned long hole_end;
157 BUG_ON(node == NULL);
159 /* Find the relevant hole to add our node to */
160 drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
161 if (hole_start > node->start || hole_end < end)
167 INIT_LIST_HEAD(&node->hole_stack);
168 list_add(&node->node_list, &hole->node_list);
170 if (node->start == hole_start) {
171 hole->hole_follows = 0;
172 list_del_init(&hole->hole_stack);
175 node->hole_follows = 0;
176 if (end != hole_end) {
177 list_add(&node->hole_stack, &mm->hole_stack);
178 node->hole_follows = 1;
184 WARN(1, "no hole found for node 0x%lx + 0x%lx\n",
185 node->start, node->size);
188 EXPORT_SYMBOL(drm_mm_reserve_node);
190 struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
196 struct drm_mm_node *node;
198 node = drm_mm_kmalloc(hole_node->mm, atomic);
199 if (unlikely(node == NULL))
202 drm_mm_insert_helper(hole_node, node, size, alignment, color);
206 EXPORT_SYMBOL(drm_mm_get_block_generic);
209 * Search for free space and insert a preallocated memory node. Returns
210 * -ENOSPC if no suitable free area is available. The preallocated memory node
213 int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
214 unsigned long size, unsigned alignment,
217 struct drm_mm_node *hole_node;
219 hole_node = drm_mm_search_free_generic(mm, size, alignment,
224 drm_mm_insert_helper(hole_node, node, size, alignment, color);
227 EXPORT_SYMBOL(drm_mm_insert_node_generic);
229 int drm_mm_insert_node(struct drm_mm *mm, struct drm_mm_node *node,
230 unsigned long size, unsigned alignment)
232 return drm_mm_insert_node_generic(mm, node, size, alignment, 0);
234 EXPORT_SYMBOL(drm_mm_insert_node);
236 static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
237 struct drm_mm_node *node,
238 unsigned long size, unsigned alignment,
240 unsigned long start, unsigned long end)
242 struct drm_mm *mm = hole_node->mm;
243 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
244 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
245 unsigned long adj_start = hole_start;
246 unsigned long adj_end = hole_end;
248 BUG_ON(!hole_node->hole_follows || node->allocated);
250 if (adj_start < start)
255 if (mm->color_adjust)
256 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
259 unsigned tmp = adj_start % alignment;
261 adj_start += alignment - tmp;
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 INIT_LIST_HEAD(&node->hole_stack);
276 list_add(&node->node_list, &hole_node->node_list);
278 BUG_ON(node->start + node->size > adj_end);
279 BUG_ON(node->start + node->size > 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;
288 struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
296 struct drm_mm_node *node;
298 node = drm_mm_kmalloc(hole_node->mm, atomic);
299 if (unlikely(node == NULL))
302 drm_mm_insert_helper_range(hole_node, node, size, alignment, color,
307 EXPORT_SYMBOL(drm_mm_get_block_range_generic);
310 * Search for free space and insert a preallocated memory node. Returns
311 * -ENOSPC if no suitable free area is available. This is for range
312 * restricted allocations. The preallocated memory node must be cleared.
314 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
315 unsigned long size, unsigned alignment, unsigned long color,
316 unsigned long start, unsigned long end)
318 struct drm_mm_node *hole_node;
320 hole_node = drm_mm_search_free_in_range_generic(mm,
321 size, alignment, color,
326 drm_mm_insert_helper_range(hole_node, node,
327 size, alignment, color,
331 EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
333 int drm_mm_insert_node_in_range(struct drm_mm *mm, struct drm_mm_node *node,
334 unsigned long size, unsigned alignment,
335 unsigned long start, unsigned long end)
337 return drm_mm_insert_node_in_range_generic(mm, node, size, alignment, 0, start, end);
339 EXPORT_SYMBOL(drm_mm_insert_node_in_range);
342 * Remove a memory node from the allocator.
344 void drm_mm_remove_node(struct drm_mm_node *node)
346 struct drm_mm *mm = node->mm;
347 struct drm_mm_node *prev_node;
349 BUG_ON(node->scanned_block || node->scanned_prev_free
350 || node->scanned_next_free);
353 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
355 if (node->hole_follows) {
356 BUG_ON(__drm_mm_hole_node_start(node) ==
357 __drm_mm_hole_node_end(node));
358 list_del(&node->hole_stack);
360 BUG_ON(__drm_mm_hole_node_start(node) !=
361 __drm_mm_hole_node_end(node));
364 if (!prev_node->hole_follows) {
365 prev_node->hole_follows = 1;
366 list_add(&prev_node->hole_stack, &mm->hole_stack);
368 list_move(&prev_node->hole_stack, &mm->hole_stack);
370 list_del(&node->node_list);
373 EXPORT_SYMBOL(drm_mm_remove_node);
376 * Remove a memory node from the allocator and free the allocated struct
377 * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
378 * drm_mm_get_block functions.
380 void drm_mm_put_block(struct drm_mm_node *node)
383 struct drm_mm *mm = node->mm;
385 drm_mm_remove_node(node);
387 spin_lock(&mm->unused_lock);
388 if (mm->num_unused < MM_UNUSED_TARGET) {
389 list_add(&node->node_list, &mm->unused_nodes);
393 spin_unlock(&mm->unused_lock);
395 EXPORT_SYMBOL(drm_mm_put_block);
397 static int check_free_hole(unsigned long start, unsigned long end,
398 unsigned long size, unsigned alignment)
400 if (end - start < size)
404 unsigned tmp = start % alignment;
406 start += alignment - tmp;
409 return end >= start + size;
412 struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
418 struct drm_mm_node *entry;
419 struct drm_mm_node *best;
420 unsigned long adj_start;
421 unsigned long adj_end;
422 unsigned long best_size;
424 BUG_ON(mm->scanned_blocks);
429 drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
430 if (mm->color_adjust) {
431 mm->color_adjust(entry, color, &adj_start, &adj_end);
432 if (adj_end <= adj_start)
436 if (!check_free_hole(adj_start, adj_end, size, alignment))
442 if (entry->size < best_size) {
444 best_size = entry->size;
450 EXPORT_SYMBOL(drm_mm_search_free_generic);
452 struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
460 struct drm_mm_node *entry;
461 struct drm_mm_node *best;
462 unsigned long adj_start;
463 unsigned long adj_end;
464 unsigned long best_size;
466 BUG_ON(mm->scanned_blocks);
471 drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
472 if (adj_start < start)
477 if (mm->color_adjust) {
478 mm->color_adjust(entry, color, &adj_start, &adj_end);
479 if (adj_end <= adj_start)
483 if (!check_free_hole(adj_start, adj_end, size, alignment))
489 if (entry->size < best_size) {
491 best_size = entry->size;
497 EXPORT_SYMBOL(drm_mm_search_free_in_range_generic);
500 * Moves an allocation. To be used with embedded struct drm_mm_node.
502 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
504 list_replace(&old->node_list, &new->node_list);
505 list_replace(&old->hole_stack, &new->hole_stack);
506 new->hole_follows = old->hole_follows;
508 new->start = old->start;
509 new->size = old->size;
510 new->color = old->color;
515 EXPORT_SYMBOL(drm_mm_replace_node);
518 * Initializa lru scanning.
520 * This simply sets up the scanning routines with the parameters for the desired
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(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_end = 0;
537 mm->scan_check_range = 0;
538 mm->prev_scanned_node = NULL;
540 EXPORT_SYMBOL(drm_mm_init_scan);
543 * Initializa lru scanning.
545 * This simply sets up the scanning routines with the parameters for the desired
546 * hole. This version is for range-restricted scans.
548 * Warning: As long as the scan list is non-empty, no other operations than
549 * adding/removing nodes to/from the scan list are allowed.
551 void drm_mm_init_scan_with_range(struct drm_mm *mm,
558 mm->scan_color = color;
559 mm->scan_alignment = alignment;
560 mm->scan_size = size;
561 mm->scanned_blocks = 0;
562 mm->scan_hit_start = 0;
563 mm->scan_hit_end = 0;
564 mm->scan_start = start;
566 mm->scan_check_range = 1;
567 mm->prev_scanned_node = NULL;
569 EXPORT_SYMBOL(drm_mm_init_scan_with_range);
572 * Add a node to the scan list that might be freed to make space for the desired
575 * Returns non-zero, if a hole has been found, zero otherwise.
577 int drm_mm_scan_add_block(struct drm_mm_node *node)
579 struct drm_mm *mm = node->mm;
580 struct drm_mm_node *prev_node;
581 unsigned long hole_start, hole_end;
582 unsigned long adj_start, adj_end;
584 mm->scanned_blocks++;
586 BUG_ON(node->scanned_block);
587 node->scanned_block = 1;
589 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
592 node->scanned_preceeds_hole = prev_node->hole_follows;
593 prev_node->hole_follows = 1;
594 list_del(&node->node_list);
595 node->node_list.prev = &prev_node->node_list;
596 node->node_list.next = &mm->prev_scanned_node->node_list;
597 mm->prev_scanned_node = node;
599 adj_start = hole_start = drm_mm_hole_node_start(prev_node);
600 adj_end = hole_end = drm_mm_hole_node_end(prev_node);
602 if (mm->scan_check_range) {
603 if (adj_start < mm->scan_start)
604 adj_start = mm->scan_start;
605 if (adj_end > mm->scan_end)
606 adj_end = mm->scan_end;
609 if (mm->color_adjust)
610 mm->color_adjust(prev_node, mm->scan_color,
611 &adj_start, &adj_end);
613 if (check_free_hole(adj_start, adj_end,
614 mm->scan_size, mm->scan_alignment)) {
615 mm->scan_hit_start = hole_start;
616 mm->scan_hit_end = hole_end;
622 EXPORT_SYMBOL(drm_mm_scan_add_block);
625 * Remove a node from the scan list.
627 * Nodes _must_ be removed in the exact same order from the scan list as they
628 * have been added, otherwise the internal state of the memory manager will be
631 * When the scan list is empty, the selected memory nodes can be freed. An
632 * immediately following drm_mm_search_free with best_match = 0 will then return
633 * the just freed block (because its at the top of the free_stack list).
635 * Returns one if this block should be evicted, zero otherwise. Will always
636 * return zero when no hole has been found.
638 int drm_mm_scan_remove_block(struct drm_mm_node *node)
640 struct drm_mm *mm = node->mm;
641 struct drm_mm_node *prev_node;
643 mm->scanned_blocks--;
645 BUG_ON(!node->scanned_block);
646 node->scanned_block = 0;
648 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
651 prev_node->hole_follows = node->scanned_preceeds_hole;
652 list_add(&node->node_list, &prev_node->node_list);
654 return (drm_mm_hole_node_end(node) > mm->scan_hit_start &&
655 node->start < mm->scan_hit_end);
657 EXPORT_SYMBOL(drm_mm_scan_remove_block);
659 int drm_mm_clean(struct drm_mm * mm)
661 struct list_head *head = &mm->head_node.node_list;
663 return (head->next->next == head);
665 EXPORT_SYMBOL(drm_mm_clean);
667 void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
669 INIT_LIST_HEAD(&mm->hole_stack);
670 INIT_LIST_HEAD(&mm->unused_nodes);
672 mm->scanned_blocks = 0;
673 spin_lock_init(&mm->unused_lock);
675 /* Clever trick to avoid a special case in the free hole tracking. */
676 INIT_LIST_HEAD(&mm->head_node.node_list);
677 INIT_LIST_HEAD(&mm->head_node.hole_stack);
678 mm->head_node.hole_follows = 1;
679 mm->head_node.scanned_block = 0;
680 mm->head_node.scanned_prev_free = 0;
681 mm->head_node.scanned_next_free = 0;
682 mm->head_node.mm = mm;
683 mm->head_node.start = start + size;
684 mm->head_node.size = start - mm->head_node.start;
685 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
687 mm->color_adjust = NULL;
689 EXPORT_SYMBOL(drm_mm_init);
691 void drm_mm_takedown(struct drm_mm * mm)
693 struct drm_mm_node *entry, *next;
695 if (WARN(!list_empty(&mm->head_node.node_list),
696 "Memory manager not clean. Delaying takedown\n")) {
700 spin_lock(&mm->unused_lock);
701 list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
702 list_del(&entry->node_list);
706 spin_unlock(&mm->unused_lock);
708 BUG_ON(mm->num_unused != 0);
710 EXPORT_SYMBOL(drm_mm_takedown);
712 static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry,
715 unsigned long hole_start, hole_end, hole_size;
717 if (entry->hole_follows) {
718 hole_start = drm_mm_hole_node_start(entry);
719 hole_end = drm_mm_hole_node_end(entry);
720 hole_size = hole_end - hole_start;
721 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
722 prefix, hole_start, hole_end,
730 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
732 struct drm_mm_node *entry;
733 unsigned long total_used = 0, total_free = 0, total = 0;
735 total_free += drm_mm_debug_hole(&mm->head_node, prefix);
737 drm_mm_for_each_node(entry, mm) {
738 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
739 prefix, entry->start, entry->start + entry->size,
741 total_used += entry->size;
742 total_free += drm_mm_debug_hole(entry, prefix);
744 total = total_free + total_used;
746 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
747 total_used, total_free);
749 EXPORT_SYMBOL(drm_mm_debug_table);
751 #if defined(CONFIG_DEBUG_FS)
752 static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
754 unsigned long hole_start, hole_end, hole_size;
756 if (entry->hole_follows) {
757 hole_start = drm_mm_hole_node_start(entry);
758 hole_end = drm_mm_hole_node_end(entry);
759 hole_size = hole_end - hole_start;
760 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
761 hole_start, hole_end, hole_size);
768 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
770 struct drm_mm_node *entry;
771 unsigned long total_used = 0, total_free = 0, total = 0;
773 total_free += drm_mm_dump_hole(m, &mm->head_node);
775 drm_mm_for_each_node(entry, mm) {
776 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
777 entry->start, entry->start + entry->size,
779 total_used += entry->size;
780 total_free += drm_mm_dump_hole(m, entry);
782 total = total_free + total_used;
784 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
787 EXPORT_SYMBOL(drm_mm_dump_table);