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>
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
)
123 struct drm_mm
*mm
= hole_node
->mm
;
124 unsigned long tmp
= 0, wasted
= 0;
125 unsigned long hole_start
= drm_mm_hole_node_start(hole_node
);
126 unsigned long hole_end
= drm_mm_hole_node_end(hole_node
);
128 BUG_ON(!hole_node
->hole_follows
|| node
->allocated
);
131 tmp
= hole_start
% alignment
;
134 hole_node
->hole_follows
= 0;
135 list_del_init(&hole_node
->hole_stack
);
137 wasted
= alignment
- tmp
;
139 node
->start
= hole_start
+ wasted
;
144 INIT_LIST_HEAD(&node
->hole_stack
);
145 list_add(&node
->node_list
, &hole_node
->node_list
);
147 BUG_ON(node
->start
+ node
->size
> hole_end
);
149 if (node
->start
+ node
->size
< hole_end
) {
150 list_add(&node
->hole_stack
, &mm
->hole_stack
);
151 node
->hole_follows
= 1;
153 node
->hole_follows
= 0;
157 struct drm_mm_node
*drm_mm_get_block_generic(struct drm_mm_node
*hole_node
,
162 struct drm_mm_node
*node
;
164 node
= drm_mm_kmalloc(hole_node
->mm
, atomic
);
165 if (unlikely(node
== NULL
))
168 drm_mm_insert_helper(hole_node
, node
, size
, alignment
);
172 EXPORT_SYMBOL(drm_mm_get_block_generic
);
175 * Search for free space and insert a preallocated memory node. Returns
176 * -ENOSPC if no suitable free area is available. The preallocated memory node
179 int drm_mm_insert_node(struct drm_mm
*mm
, struct drm_mm_node
*node
,
180 unsigned long size
, unsigned alignment
)
182 struct drm_mm_node
*hole_node
;
184 hole_node
= drm_mm_search_free(mm
, size
, alignment
, 0);
188 drm_mm_insert_helper(hole_node
, node
, size
, alignment
);
192 EXPORT_SYMBOL(drm_mm_insert_node
);
194 static void drm_mm_insert_helper_range(struct drm_mm_node
*hole_node
,
195 struct drm_mm_node
*node
,
196 unsigned long size
, unsigned alignment
,
197 unsigned long start
, unsigned long end
)
199 struct drm_mm
*mm
= hole_node
->mm
;
200 unsigned long tmp
= 0, wasted
= 0;
201 unsigned long hole_start
= drm_mm_hole_node_start(hole_node
);
202 unsigned long hole_end
= drm_mm_hole_node_end(hole_node
);
204 BUG_ON(!hole_node
->hole_follows
|| node
->allocated
);
206 if (hole_start
< start
)
207 wasted
+= start
- hole_start
;
209 tmp
= (hole_start
+ wasted
) % alignment
;
212 wasted
+= alignment
- tmp
;
215 hole_node
->hole_follows
= 0;
216 list_del_init(&hole_node
->hole_stack
);
219 node
->start
= hole_start
+ wasted
;
224 INIT_LIST_HEAD(&node
->hole_stack
);
225 list_add(&node
->node_list
, &hole_node
->node_list
);
227 BUG_ON(node
->start
+ node
->size
> hole_end
);
228 BUG_ON(node
->start
+ node
->size
> end
);
230 if (node
->start
+ node
->size
< hole_end
) {
231 list_add(&node
->hole_stack
, &mm
->hole_stack
);
232 node
->hole_follows
= 1;
234 node
->hole_follows
= 0;
238 struct drm_mm_node
*drm_mm_get_block_range_generic(struct drm_mm_node
*hole_node
,
245 struct drm_mm_node
*node
;
247 node
= drm_mm_kmalloc(hole_node
->mm
, atomic
);
248 if (unlikely(node
== NULL
))
251 drm_mm_insert_helper_range(hole_node
, node
, size
, alignment
,
256 EXPORT_SYMBOL(drm_mm_get_block_range_generic
);
259 * Search for free space and insert a preallocated memory node. Returns
260 * -ENOSPC if no suitable free area is available. This is for range
261 * restricted allocations. The preallocated memory node must be cleared.
263 int drm_mm_insert_node_in_range(struct drm_mm
*mm
, struct drm_mm_node
*node
,
264 unsigned long size
, unsigned alignment
,
265 unsigned long start
, unsigned long end
)
267 struct drm_mm_node
*hole_node
;
269 hole_node
= drm_mm_search_free_in_range(mm
, size
, alignment
,
274 drm_mm_insert_helper_range(hole_node
, node
, size
, alignment
,
279 EXPORT_SYMBOL(drm_mm_insert_node_in_range
);
282 * Remove a memory node from the allocator.
284 void drm_mm_remove_node(struct drm_mm_node
*node
)
286 struct drm_mm
*mm
= node
->mm
;
287 struct drm_mm_node
*prev_node
;
289 BUG_ON(node
->scanned_block
|| node
->scanned_prev_free
290 || node
->scanned_next_free
);
293 list_entry(node
->node_list
.prev
, struct drm_mm_node
, node_list
);
295 if (node
->hole_follows
) {
296 BUG_ON(drm_mm_hole_node_start(node
)
297 == drm_mm_hole_node_end(node
));
298 list_del(&node
->hole_stack
);
300 BUG_ON(drm_mm_hole_node_start(node
)
301 != drm_mm_hole_node_end(node
));
303 if (!prev_node
->hole_follows
) {
304 prev_node
->hole_follows
= 1;
305 list_add(&prev_node
->hole_stack
, &mm
->hole_stack
);
307 list_move(&prev_node
->hole_stack
, &mm
->hole_stack
);
309 list_del(&node
->node_list
);
312 EXPORT_SYMBOL(drm_mm_remove_node
);
315 * Remove a memory node from the allocator and free the allocated struct
316 * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
317 * drm_mm_get_block functions.
319 void drm_mm_put_block(struct drm_mm_node
*node
)
322 struct drm_mm
*mm
= node
->mm
;
324 drm_mm_remove_node(node
);
326 spin_lock(&mm
->unused_lock
);
327 if (mm
->num_unused
< MM_UNUSED_TARGET
) {
328 list_add(&node
->node_list
, &mm
->unused_nodes
);
332 spin_unlock(&mm
->unused_lock
);
334 EXPORT_SYMBOL(drm_mm_put_block
);
336 static int check_free_hole(unsigned long start
, unsigned long end
,
337 unsigned long size
, unsigned alignment
)
341 if (end
- start
< size
)
345 unsigned tmp
= start
% alignment
;
347 wasted
= alignment
- tmp
;
350 if (end
>= start
+ size
+ wasted
) {
357 struct drm_mm_node
*drm_mm_search_free(const struct drm_mm
*mm
,
359 unsigned alignment
, int best_match
)
361 struct drm_mm_node
*entry
;
362 struct drm_mm_node
*best
;
363 unsigned long best_size
;
365 BUG_ON(mm
->scanned_blocks
);
370 list_for_each_entry(entry
, &mm
->hole_stack
, hole_stack
) {
371 BUG_ON(!entry
->hole_follows
);
372 if (!check_free_hole(drm_mm_hole_node_start(entry
),
373 drm_mm_hole_node_end(entry
),
380 if (entry
->size
< best_size
) {
382 best_size
= entry
->size
;
388 EXPORT_SYMBOL(drm_mm_search_free
);
390 struct drm_mm_node
*drm_mm_search_free_in_range(const struct drm_mm
*mm
,
397 struct drm_mm_node
*entry
;
398 struct drm_mm_node
*best
;
399 unsigned long best_size
;
401 BUG_ON(mm
->scanned_blocks
);
406 list_for_each_entry(entry
, &mm
->hole_stack
, hole_stack
) {
407 unsigned long adj_start
= drm_mm_hole_node_start(entry
) < start
?
408 start
: drm_mm_hole_node_start(entry
);
409 unsigned long adj_end
= drm_mm_hole_node_end(entry
) > end
?
410 end
: drm_mm_hole_node_end(entry
);
412 BUG_ON(!entry
->hole_follows
);
413 if (!check_free_hole(adj_start
, adj_end
, size
, alignment
))
419 if (entry
->size
< best_size
) {
421 best_size
= entry
->size
;
427 EXPORT_SYMBOL(drm_mm_search_free_in_range
);
430 * Moves an allocation. To be used with embedded struct drm_mm_node.
432 void drm_mm_replace_node(struct drm_mm_node
*old
, struct drm_mm_node
*new)
434 list_replace(&old
->node_list
, &new->node_list
);
435 list_replace(&old
->hole_stack
, &new->hole_stack
);
436 new->hole_follows
= old
->hole_follows
;
438 new->start
= old
->start
;
439 new->size
= old
->size
;
444 EXPORT_SYMBOL(drm_mm_replace_node
);
447 * Initializa lru scanning.
449 * This simply sets up the scanning routines with the parameters for the desired
452 * Warning: As long as the scan list is non-empty, no other operations than
453 * adding/removing nodes to/from the scan list are allowed.
455 void drm_mm_init_scan(struct drm_mm
*mm
, unsigned long size
,
458 mm
->scan_alignment
= alignment
;
459 mm
->scan_size
= size
;
460 mm
->scanned_blocks
= 0;
461 mm
->scan_hit_start
= 0;
462 mm
->scan_hit_size
= 0;
463 mm
->scan_check_range
= 0;
464 mm
->prev_scanned_node
= NULL
;
466 EXPORT_SYMBOL(drm_mm_init_scan
);
469 * Initializa lru scanning.
471 * This simply sets up the scanning routines with the parameters for the desired
472 * hole. This version is for range-restricted scans.
474 * Warning: As long as the scan list is non-empty, no other operations than
475 * adding/removing nodes to/from the scan list are allowed.
477 void drm_mm_init_scan_with_range(struct drm_mm
*mm
, unsigned long size
,
482 mm
->scan_alignment
= alignment
;
483 mm
->scan_size
= size
;
484 mm
->scanned_blocks
= 0;
485 mm
->scan_hit_start
= 0;
486 mm
->scan_hit_size
= 0;
487 mm
->scan_start
= start
;
489 mm
->scan_check_range
= 1;
490 mm
->prev_scanned_node
= NULL
;
492 EXPORT_SYMBOL(drm_mm_init_scan_with_range
);
495 * Add a node to the scan list that might be freed to make space for the desired
498 * Returns non-zero, if a hole has been found, zero otherwise.
500 int drm_mm_scan_add_block(struct drm_mm_node
*node
)
502 struct drm_mm
*mm
= node
->mm
;
503 struct drm_mm_node
*prev_node
;
504 unsigned long hole_start
, hole_end
;
505 unsigned long adj_start
;
506 unsigned long adj_end
;
508 mm
->scanned_blocks
++;
510 BUG_ON(node
->scanned_block
);
511 node
->scanned_block
= 1;
513 prev_node
= list_entry(node
->node_list
.prev
, struct drm_mm_node
,
516 node
->scanned_preceeds_hole
= prev_node
->hole_follows
;
517 prev_node
->hole_follows
= 1;
518 list_del(&node
->node_list
);
519 node
->node_list
.prev
= &prev_node
->node_list
;
520 node
->node_list
.next
= &mm
->prev_scanned_node
->node_list
;
521 mm
->prev_scanned_node
= node
;
523 hole_start
= drm_mm_hole_node_start(prev_node
);
524 hole_end
= drm_mm_hole_node_end(prev_node
);
525 if (mm
->scan_check_range
) {
526 adj_start
= hole_start
< mm
->scan_start
?
527 mm
->scan_start
: hole_start
;
528 adj_end
= hole_end
> mm
->scan_end
?
529 mm
->scan_end
: hole_end
;
531 adj_start
= hole_start
;
535 if (check_free_hole(adj_start
, adj_end
,
536 mm
->scan_size
, mm
->scan_alignment
)) {
537 mm
->scan_hit_start
= hole_start
;
538 mm
->scan_hit_size
= hole_end
;
545 EXPORT_SYMBOL(drm_mm_scan_add_block
);
548 * Remove a node from the scan list.
550 * Nodes _must_ be removed in the exact same order from the scan list as they
551 * have been added, otherwise the internal state of the memory manager will be
554 * When the scan list is empty, the selected memory nodes can be freed. An
555 * immediately following drm_mm_search_free with best_match = 0 will then return
556 * the just freed block (because its at the top of the free_stack list).
558 * Returns one if this block should be evicted, zero otherwise. Will always
559 * return zero when no hole has been found.
561 int drm_mm_scan_remove_block(struct drm_mm_node
*node
)
563 struct drm_mm
*mm
= node
->mm
;
564 struct drm_mm_node
*prev_node
;
566 mm
->scanned_blocks
--;
568 BUG_ON(!node
->scanned_block
);
569 node
->scanned_block
= 0;
571 prev_node
= list_entry(node
->node_list
.prev
, struct drm_mm_node
,
574 prev_node
->hole_follows
= node
->scanned_preceeds_hole
;
575 INIT_LIST_HEAD(&node
->node_list
);
576 list_add(&node
->node_list
, &prev_node
->node_list
);
578 /* Only need to check for containement because start&size for the
579 * complete resulting free block (not just the desired part) is
581 if (node
->start
>= mm
->scan_hit_start
&&
582 node
->start
+ node
->size
583 <= mm
->scan_hit_start
+ mm
->scan_hit_size
) {
589 EXPORT_SYMBOL(drm_mm_scan_remove_block
);
591 int drm_mm_clean(struct drm_mm
* mm
)
593 struct list_head
*head
= &mm
->head_node
.node_list
;
595 return (head
->next
->next
== head
);
597 EXPORT_SYMBOL(drm_mm_clean
);
599 int drm_mm_init(struct drm_mm
* mm
, unsigned long start
, unsigned long size
)
601 INIT_LIST_HEAD(&mm
->hole_stack
);
602 INIT_LIST_HEAD(&mm
->unused_nodes
);
604 mm
->scanned_blocks
= 0;
605 spin_lock_init(&mm
->unused_lock
);
607 /* Clever trick to avoid a special case in the free hole tracking. */
608 INIT_LIST_HEAD(&mm
->head_node
.node_list
);
609 INIT_LIST_HEAD(&mm
->head_node
.hole_stack
);
610 mm
->head_node
.hole_follows
= 1;
611 mm
->head_node
.scanned_block
= 0;
612 mm
->head_node
.scanned_prev_free
= 0;
613 mm
->head_node
.scanned_next_free
= 0;
614 mm
->head_node
.mm
= mm
;
615 mm
->head_node
.start
= start
+ size
;
616 mm
->head_node
.size
= start
- mm
->head_node
.start
;
617 list_add_tail(&mm
->head_node
.hole_stack
, &mm
->hole_stack
);
621 EXPORT_SYMBOL(drm_mm_init
);
623 void drm_mm_takedown(struct drm_mm
* mm
)
625 struct drm_mm_node
*entry
, *next
;
627 if (!list_empty(&mm
->head_node
.node_list
)) {
628 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
632 spin_lock(&mm
->unused_lock
);
633 list_for_each_entry_safe(entry
, next
, &mm
->unused_nodes
, node_list
) {
634 list_del(&entry
->node_list
);
638 spin_unlock(&mm
->unused_lock
);
640 BUG_ON(mm
->num_unused
!= 0);
642 EXPORT_SYMBOL(drm_mm_takedown
);
644 void drm_mm_debug_table(struct drm_mm
*mm
, const char *prefix
)
646 struct drm_mm_node
*entry
;
647 unsigned long total_used
= 0, total_free
= 0, total
= 0;
648 unsigned long hole_start
, hole_end
, hole_size
;
650 hole_start
= drm_mm_hole_node_start(&mm
->head_node
);
651 hole_end
= drm_mm_hole_node_end(&mm
->head_node
);
652 hole_size
= hole_end
- hole_start
;
654 printk(KERN_DEBUG
"%s 0x%08lx-0x%08lx: %8lu: free\n",
655 prefix
, hole_start
, hole_end
,
657 total_free
+= hole_size
;
659 drm_mm_for_each_node(entry
, mm
) {
660 printk(KERN_DEBUG
"%s 0x%08lx-0x%08lx: %8lu: used\n",
661 prefix
, entry
->start
, entry
->start
+ entry
->size
,
663 total_used
+= entry
->size
;
665 if (entry
->hole_follows
) {
666 hole_start
= drm_mm_hole_node_start(entry
);
667 hole_end
= drm_mm_hole_node_end(entry
);
668 hole_size
= hole_end
- hole_start
;
669 printk(KERN_DEBUG
"%s 0x%08lx-0x%08lx: %8lu: free\n",
670 prefix
, hole_start
, hole_end
,
672 total_free
+= hole_size
;
675 total
= total_free
+ total_used
;
677 printk(KERN_DEBUG
"%s total: %lu, used %lu free %lu\n", prefix
, total
,
678 total_used
, total_free
);
680 EXPORT_SYMBOL(drm_mm_debug_table
);
682 #if defined(CONFIG_DEBUG_FS)
683 int drm_mm_dump_table(struct seq_file
*m
, struct drm_mm
*mm
)
685 struct drm_mm_node
*entry
;
686 unsigned long total_used
= 0, total_free
= 0, total
= 0;
687 unsigned long hole_start
, hole_end
, hole_size
;
689 hole_start
= drm_mm_hole_node_start(&mm
->head_node
);
690 hole_end
= drm_mm_hole_node_end(&mm
->head_node
);
691 hole_size
= hole_end
- hole_start
;
693 seq_printf(m
, "0x%08lx-0x%08lx: 0x%08lx: free\n",
694 hole_start
, hole_end
, hole_size
);
695 total_free
+= hole_size
;
697 drm_mm_for_each_node(entry
, mm
) {
698 seq_printf(m
, "0x%08lx-0x%08lx: 0x%08lx: used\n",
699 entry
->start
, entry
->start
+ entry
->size
,
701 total_used
+= entry
->size
;
702 if (entry
->hole_follows
) {
703 hole_start
= drm_mm_hole_node_start(entry
);
704 hole_end
= drm_mm_hole_node_end(entry
);
705 hole_size
= hole_end
- hole_start
;
706 seq_printf(m
, "0x%08lx-0x%08lx: 0x%08lx: free\n",
707 hole_start
, hole_end
, hole_size
);
708 total_free
+= hole_size
;
711 total
= total_free
+ total_used
;
713 seq_printf(m
, "total: %lu, used %lu free %lu\n", total
, total_used
, total_free
);
716 EXPORT_SYMBOL(drm_mm_dump_table
);