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1/**************************************************************************
2 *
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
4 * All Rights Reserved.
5 *
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:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
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.
25 *
26 *
27 **************************************************************************/
28
29/*
30 * Generic simple memory manager implementation. Intended to be used as a base
31 * class implementation for more advanced memory managers.
32 *
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.
37 *
38 * Aligned allocations can also see improvement.
39 *
40 * Authors:
41 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
42 */
43
44#include "drmP.h"
45#include "drm_mm.h"
46#include <linux/slab.h>
47#include <linux/seq_file.h>
48
49#define MM_UNUSED_TARGET 4
50
51static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
52{
53 struct drm_mm_node *child;
54
55 if (atomic)
56 child = kzalloc(sizeof(*child), GFP_ATOMIC);
57 else
58 child = kzalloc(sizeof(*child), GFP_KERNEL);
59
60 if (unlikely(child == NULL)) {
61 spin_lock(&mm->unused_lock);
62 if (list_empty(&mm->unused_nodes))
63 child = NULL;
64 else {
65 child =
66 list_entry(mm->unused_nodes.next,
67 struct drm_mm_node, node_list);
68 list_del(&child->node_list);
69 --mm->num_unused;
70 }
71 spin_unlock(&mm->unused_lock);
72 }
73 return child;
74}
75
76/* drm_mm_pre_get() - pre allocate drm_mm_node structure
77 * drm_mm: memory manager struct we are pre-allocating for
78 *
79 * Returns 0 on success or -ENOMEM if allocation fails.
80 */
81int drm_mm_pre_get(struct drm_mm *mm)
82{
83 struct drm_mm_node *node;
84
85 spin_lock(&mm->unused_lock);
86 while (mm->num_unused < MM_UNUSED_TARGET) {
87 spin_unlock(&mm->unused_lock);
88 node = kzalloc(sizeof(*node), GFP_KERNEL);
89 spin_lock(&mm->unused_lock);
90
91 if (unlikely(node == NULL)) {
92 int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
93 spin_unlock(&mm->unused_lock);
94 return ret;
95 }
96 ++mm->num_unused;
97 list_add_tail(&node->node_list, &mm->unused_nodes);
98 }
99 spin_unlock(&mm->unused_lock);
100 return 0;
101}
102EXPORT_SYMBOL(drm_mm_pre_get);
103
104static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
105{
106 return hole_node->start + hole_node->size;
107}
108
109static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
110{
111 struct drm_mm_node *next_node =
112 list_entry(hole_node->node_list.next, struct drm_mm_node,
113 node_list);
114
115 return next_node->start;
116}
117
118static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
119 struct drm_mm_node *node,
120 unsigned long size, unsigned alignment)
121{
122 struct drm_mm *mm = hole_node->mm;
123 unsigned long tmp = 0, wasted = 0;
124 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
125 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
126
127 BUG_ON(!hole_node->hole_follows || node->allocated);
128
129 if (alignment)
130 tmp = hole_start % alignment;
131
132 if (!tmp) {
133 hole_node->hole_follows = 0;
134 list_del_init(&hole_node->hole_stack);
135 } else
136 wasted = alignment - tmp;
137
138 node->start = hole_start + wasted;
139 node->size = size;
140 node->mm = mm;
141 node->allocated = 1;
142
143 INIT_LIST_HEAD(&node->hole_stack);
144 list_add(&node->node_list, &hole_node->node_list);
145
146 BUG_ON(node->start + node->size > hole_end);
147
148 if (node->start + node->size < hole_end) {
149 list_add(&node->hole_stack, &mm->hole_stack);
150 node->hole_follows = 1;
151 } else {
152 node->hole_follows = 0;
153 }
154}
155
156struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
157 unsigned long size,
158 unsigned alignment,
159 int atomic)
160{
161 struct drm_mm_node *node;
162
163 node = drm_mm_kmalloc(hole_node->mm, atomic);
164 if (unlikely(node == NULL))
165 return NULL;
166
167 drm_mm_insert_helper(hole_node, node, size, alignment);
168
169 return node;
170}
171EXPORT_SYMBOL(drm_mm_get_block_generic);
172
173/**
174 * Search for free space and insert a preallocated memory node. Returns
175 * -ENOSPC if no suitable free area is available. The preallocated memory node
176 * must be cleared.
177 */
178int drm_mm_insert_node(struct drm_mm *mm, struct drm_mm_node *node,
179 unsigned long size, unsigned alignment)
180{
181 struct drm_mm_node *hole_node;
182
183 hole_node = drm_mm_search_free(mm, size, alignment, 0);
184 if (!hole_node)
185 return -ENOSPC;
186
187 drm_mm_insert_helper(hole_node, node, size, alignment);
188
189 return 0;
190}
191EXPORT_SYMBOL(drm_mm_insert_node);
192
193static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
194 struct drm_mm_node *node,
195 unsigned long size, unsigned alignment,
196 unsigned long start, unsigned long end)
197{
198 struct drm_mm *mm = hole_node->mm;
199 unsigned long tmp = 0, wasted = 0;
200 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
201 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
202
203 BUG_ON(!hole_node->hole_follows || node->allocated);
204
205 if (hole_start < start)
206 wasted += start - hole_start;
207 if (alignment)
208 tmp = (hole_start + wasted) % alignment;
209
210 if (tmp)
211 wasted += alignment - tmp;
212
213 if (!wasted) {
214 hole_node->hole_follows = 0;
215 list_del_init(&hole_node->hole_stack);
216 }
217
218 node->start = hole_start + wasted;
219 node->size = size;
220 node->mm = mm;
221 node->allocated = 1;
222
223 INIT_LIST_HEAD(&node->hole_stack);
224 list_add(&node->node_list, &hole_node->node_list);
225
226 BUG_ON(node->start + node->size > hole_end);
227 BUG_ON(node->start + node->size > end);
228
229 if (node->start + node->size < hole_end) {
230 list_add(&node->hole_stack, &mm->hole_stack);
231 node->hole_follows = 1;
232 } else {
233 node->hole_follows = 0;
234 }
235}
236
237struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
238 unsigned long size,
239 unsigned alignment,
240 unsigned long start,
241 unsigned long end,
242 int atomic)
243{
244 struct drm_mm_node *node;
245
246 node = drm_mm_kmalloc(hole_node->mm, atomic);
247 if (unlikely(node == NULL))
248 return NULL;
249
250 drm_mm_insert_helper_range(hole_node, node, size, alignment,
251 start, end);
252
253 return node;
254}
255EXPORT_SYMBOL(drm_mm_get_block_range_generic);
256
257/**
258 * Search for free space and insert a preallocated memory node. Returns
259 * -ENOSPC if no suitable free area is available. This is for range
260 * restricted allocations. The preallocated memory node must be cleared.
261 */
262int drm_mm_insert_node_in_range(struct drm_mm *mm, struct drm_mm_node *node,
263 unsigned long size, unsigned alignment,
264 unsigned long start, unsigned long end)
265{
266 struct drm_mm_node *hole_node;
267
268 hole_node = drm_mm_search_free_in_range(mm, size, alignment,
269 start, end, 0);
270 if (!hole_node)
271 return -ENOSPC;
272
273 drm_mm_insert_helper_range(hole_node, node, size, alignment,
274 start, end);
275
276 return 0;
277}
278EXPORT_SYMBOL(drm_mm_insert_node_in_range);
279
280/**
281 * Remove a memory node from the allocator.
282 */
283void drm_mm_remove_node(struct drm_mm_node *node)
284{
285 struct drm_mm *mm = node->mm;
286 struct drm_mm_node *prev_node;
287
288 BUG_ON(node->scanned_block || node->scanned_prev_free
289 || node->scanned_next_free);
290
291 prev_node =
292 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
293
294 if (node->hole_follows) {
295 BUG_ON(drm_mm_hole_node_start(node)
296 == drm_mm_hole_node_end(node));
297 list_del(&node->hole_stack);
298 } else
299 BUG_ON(drm_mm_hole_node_start(node)
300 != drm_mm_hole_node_end(node));
301
302 if (!prev_node->hole_follows) {
303 prev_node->hole_follows = 1;
304 list_add(&prev_node->hole_stack, &mm->hole_stack);
305 } else
306 list_move(&prev_node->hole_stack, &mm->hole_stack);
307
308 list_del(&node->node_list);
309 node->allocated = 0;
310}
311EXPORT_SYMBOL(drm_mm_remove_node);
312
313/*
314 * Remove a memory node from the allocator and free the allocated struct
315 * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
316 * drm_mm_get_block functions.
317 */
318void drm_mm_put_block(struct drm_mm_node *node)
319{
320
321 struct drm_mm *mm = node->mm;
322
323 drm_mm_remove_node(node);
324
325 spin_lock(&mm->unused_lock);
326 if (mm->num_unused < MM_UNUSED_TARGET) {
327 list_add(&node->node_list, &mm->unused_nodes);
328 ++mm->num_unused;
329 } else
330 kfree(node);
331 spin_unlock(&mm->unused_lock);
332}
333EXPORT_SYMBOL(drm_mm_put_block);
334
335static int check_free_hole(unsigned long start, unsigned long end,
336 unsigned long size, unsigned alignment)
337{
338 unsigned wasted = 0;
339
340 if (end - start < size)
341 return 0;
342
343 if (alignment) {
344 unsigned tmp = start % alignment;
345 if (tmp)
346 wasted = alignment - tmp;
347 }
348
349 if (end >= start + size + wasted) {
350 return 1;
351 }
352
353 return 0;
354}
355
356struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
357 unsigned long size,
358 unsigned alignment, int best_match)
359{
360 struct drm_mm_node *entry;
361 struct drm_mm_node *best;
362 unsigned long best_size;
363
364 BUG_ON(mm->scanned_blocks);
365
366 best = NULL;
367 best_size = ~0UL;
368
369 list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
370 BUG_ON(!entry->hole_follows);
371 if (!check_free_hole(drm_mm_hole_node_start(entry),
372 drm_mm_hole_node_end(entry),
373 size, alignment))
374 continue;
375
376 if (!best_match)
377 return entry;
378
379 if (entry->size < best_size) {
380 best = entry;
381 best_size = entry->size;
382 }
383 }
384
385 return best;
386}
387EXPORT_SYMBOL(drm_mm_search_free);
388
389struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
390 unsigned long size,
391 unsigned alignment,
392 unsigned long start,
393 unsigned long end,
394 int best_match)
395{
396 struct drm_mm_node *entry;
397 struct drm_mm_node *best;
398 unsigned long best_size;
399
400 BUG_ON(mm->scanned_blocks);
401
402 best = NULL;
403 best_size = ~0UL;
404
405 list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
406 unsigned long adj_start = drm_mm_hole_node_start(entry) < start ?
407 start : drm_mm_hole_node_start(entry);
408 unsigned long adj_end = drm_mm_hole_node_end(entry) > end ?
409 end : drm_mm_hole_node_end(entry);
410
411 BUG_ON(!entry->hole_follows);
412 if (!check_free_hole(adj_start, adj_end, size, alignment))
413 continue;
414
415 if (!best_match)
416 return entry;
417
418 if (entry->size < best_size) {
419 best = entry;
420 best_size = entry->size;
421 }
422 }
423
424 return best;
425}
426EXPORT_SYMBOL(drm_mm_search_free_in_range);
427
428/**
429 * Moves an allocation. To be used with embedded struct drm_mm_node.
430 */
431void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
432{
433 list_replace(&old->node_list, &new->node_list);
434 list_replace(&old->hole_stack, &new->hole_stack);
435 new->hole_follows = old->hole_follows;
436 new->mm = old->mm;
437 new->start = old->start;
438 new->size = old->size;
439
440 old->allocated = 0;
441 new->allocated = 1;
442}
443EXPORT_SYMBOL(drm_mm_replace_node);
444
445/**
446 * Initializa lru scanning.
447 *
448 * This simply sets up the scanning routines with the parameters for the desired
449 * hole.
450 *
451 * Warning: As long as the scan list is non-empty, no other operations than
452 * adding/removing nodes to/from the scan list are allowed.
453 */
454void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
455 unsigned alignment)
456{
457 mm->scan_alignment = alignment;
458 mm->scan_size = size;
459 mm->scanned_blocks = 0;
460 mm->scan_hit_start = 0;
461 mm->scan_hit_size = 0;
462 mm->scan_check_range = 0;
463 mm->prev_scanned_node = NULL;
464}
465EXPORT_SYMBOL(drm_mm_init_scan);
466
467/**
468 * Initializa lru scanning.
469 *
470 * This simply sets up the scanning routines with the parameters for the desired
471 * hole. This version is for range-restricted scans.
472 *
473 * Warning: As long as the scan list is non-empty, no other operations than
474 * adding/removing nodes to/from the scan list are allowed.
475 */
476void drm_mm_init_scan_with_range(struct drm_mm *mm, unsigned long size,
477 unsigned alignment,
478 unsigned long start,
479 unsigned long end)
480{
481 mm->scan_alignment = alignment;
482 mm->scan_size = size;
483 mm->scanned_blocks = 0;
484 mm->scan_hit_start = 0;
485 mm->scan_hit_size = 0;
486 mm->scan_start = start;
487 mm->scan_end = end;
488 mm->scan_check_range = 1;
489 mm->prev_scanned_node = NULL;
490}
491EXPORT_SYMBOL(drm_mm_init_scan_with_range);
492
493/**
494 * Add a node to the scan list that might be freed to make space for the desired
495 * hole.
496 *
497 * Returns non-zero, if a hole has been found, zero otherwise.
498 */
499int drm_mm_scan_add_block(struct drm_mm_node *node)
500{
501 struct drm_mm *mm = node->mm;
502 struct drm_mm_node *prev_node;
503 unsigned long hole_start, hole_end;
504 unsigned long adj_start;
505 unsigned long adj_end;
506
507 mm->scanned_blocks++;
508
509 BUG_ON(node->scanned_block);
510 node->scanned_block = 1;
511
512 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
513 node_list);
514
515 node->scanned_preceeds_hole = prev_node->hole_follows;
516 prev_node->hole_follows = 1;
517 list_del(&node->node_list);
518 node->node_list.prev = &prev_node->node_list;
519 node->node_list.next = &mm->prev_scanned_node->node_list;
520 mm->prev_scanned_node = node;
521
522 hole_start = drm_mm_hole_node_start(prev_node);
523 hole_end = drm_mm_hole_node_end(prev_node);
524 if (mm->scan_check_range) {
525 adj_start = hole_start < mm->scan_start ?
526 mm->scan_start : hole_start;
527 adj_end = hole_end > mm->scan_end ?
528 mm->scan_end : hole_end;
529 } else {
530 adj_start = hole_start;
531 adj_end = hole_end;
532 }
533
534 if (check_free_hole(adj_start , adj_end,
535 mm->scan_size, mm->scan_alignment)) {
536 mm->scan_hit_start = hole_start;
537 mm->scan_hit_size = hole_end;
538
539 return 1;
540 }
541
542 return 0;
543}
544EXPORT_SYMBOL(drm_mm_scan_add_block);
545
546/**
547 * Remove a node from the scan list.
548 *
549 * Nodes _must_ be removed in the exact same order from the scan list as they
550 * have been added, otherwise the internal state of the memory manager will be
551 * corrupted.
552 *
553 * When the scan list is empty, the selected memory nodes can be freed. An
554 * immediately following drm_mm_search_free with best_match = 0 will then return
555 * the just freed block (because its at the top of the free_stack list).
556 *
557 * Returns one if this block should be evicted, zero otherwise. Will always
558 * return zero when no hole has been found.
559 */
560int drm_mm_scan_remove_block(struct drm_mm_node *node)
561{
562 struct drm_mm *mm = node->mm;
563 struct drm_mm_node *prev_node;
564
565 mm->scanned_blocks--;
566
567 BUG_ON(!node->scanned_block);
568 node->scanned_block = 0;
569
570 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
571 node_list);
572
573 prev_node->hole_follows = node->scanned_preceeds_hole;
574 INIT_LIST_HEAD(&node->node_list);
575 list_add(&node->node_list, &prev_node->node_list);
576
577 /* Only need to check for containement because start&size for the
578 * complete resulting free block (not just the desired part) is
579 * stored. */
580 if (node->start >= mm->scan_hit_start &&
581 node->start + node->size
582 <= mm->scan_hit_start + mm->scan_hit_size) {
583 return 1;
584 }
585
586 return 0;
587}
588EXPORT_SYMBOL(drm_mm_scan_remove_block);
589
590int drm_mm_clean(struct drm_mm * mm)
591{
592 struct list_head *head = &mm->head_node.node_list;
593
594 return (head->next->next == head);
595}
596EXPORT_SYMBOL(drm_mm_clean);
597
598int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
599{
600 INIT_LIST_HEAD(&mm->hole_stack);
601 INIT_LIST_HEAD(&mm->unused_nodes);
602 mm->num_unused = 0;
603 mm->scanned_blocks = 0;
604 spin_lock_init(&mm->unused_lock);
605
606 /* Clever trick to avoid a special case in the free hole tracking. */
607 INIT_LIST_HEAD(&mm->head_node.node_list);
608 INIT_LIST_HEAD(&mm->head_node.hole_stack);
609 mm->head_node.hole_follows = 1;
610 mm->head_node.scanned_block = 0;
611 mm->head_node.scanned_prev_free = 0;
612 mm->head_node.scanned_next_free = 0;
613 mm->head_node.mm = mm;
614 mm->head_node.start = start + size;
615 mm->head_node.size = start - mm->head_node.start;
616 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
617
618 return 0;
619}
620EXPORT_SYMBOL(drm_mm_init);
621
622void drm_mm_takedown(struct drm_mm * mm)
623{
624 struct drm_mm_node *entry, *next;
625
626 if (!list_empty(&mm->head_node.node_list)) {
627 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
628 return;
629 }
630
631 spin_lock(&mm->unused_lock);
632 list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
633 list_del(&entry->node_list);
634 kfree(entry);
635 --mm->num_unused;
636 }
637 spin_unlock(&mm->unused_lock);
638
639 BUG_ON(mm->num_unused != 0);
640}
641EXPORT_SYMBOL(drm_mm_takedown);
642
643void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
644{
645 struct drm_mm_node *entry;
646 unsigned long total_used = 0, total_free = 0, total = 0;
647 unsigned long hole_start, hole_end, hole_size;
648
649 hole_start = drm_mm_hole_node_start(&mm->head_node);
650 hole_end = drm_mm_hole_node_end(&mm->head_node);
651 hole_size = hole_end - hole_start;
652 if (hole_size)
653 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
654 prefix, hole_start, hole_end,
655 hole_size);
656 total_free += hole_size;
657
658 drm_mm_for_each_node(entry, mm) {
659 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
660 prefix, entry->start, entry->start + entry->size,
661 entry->size);
662 total_used += entry->size;
663
664 if (entry->hole_follows) {
665 hole_start = drm_mm_hole_node_start(entry);
666 hole_end = drm_mm_hole_node_end(entry);
667 hole_size = hole_end - hole_start;
668 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
669 prefix, hole_start, hole_end,
670 hole_size);
671 total_free += hole_size;
672 }
673 }
674 total = total_free + total_used;
675
676 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
677 total_used, total_free);
678}
679EXPORT_SYMBOL(drm_mm_debug_table);
680
681#if defined(CONFIG_DEBUG_FS)
682int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
683{
684 struct drm_mm_node *entry;
685 unsigned long total_used = 0, total_free = 0, total = 0;
686 unsigned long hole_start, hole_end, hole_size;
687
688 hole_start = drm_mm_hole_node_start(&mm->head_node);
689 hole_end = drm_mm_hole_node_end(&mm->head_node);
690 hole_size = hole_end - hole_start;
691 if (hole_size)
692 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
693 hole_start, hole_end, hole_size);
694 total_free += hole_size;
695
696 drm_mm_for_each_node(entry, mm) {
697 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
698 entry->start, entry->start + entry->size,
699 entry->size);
700 total_used += entry->size;
701 if (entry->hole_follows) {
702 hole_start = drm_mm_hole_node_start(entry);
703 hole_end = drm_mm_hole_node_end(entry);
704 hole_size = hole_end - hole_start;
705 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
706 hole_start, hole_end, hole_size);
707 total_free += hole_size;
708 }
709 }
710 total = total_free + total_used;
711
712 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
713 return 0;
714}
715EXPORT_SYMBOL(drm_mm_dump_table);
716#endif
1/**************************************************************************
2 *
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
4 * All Rights Reserved.
5 *
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:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
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.
25 *
26 *
27 **************************************************************************/
28
29/*
30 * Generic simple memory manager implementation. Intended to be used as a base
31 * class implementation for more advanced memory managers.
32 *
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.
37 *
38 * Aligned allocations can also see improvement.
39 *
40 * Authors:
41 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
42 */
43
44#include "drmP.h"
45#include "drm_mm.h"
46#include <linux/slab.h>
47#include <linux/seq_file.h>
48#include <linux/export.h>
49
50#define MM_UNUSED_TARGET 4
51
52static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
53{
54 struct drm_mm_node *child;
55
56 if (atomic)
57 child = kzalloc(sizeof(*child), GFP_ATOMIC);
58 else
59 child = kzalloc(sizeof(*child), GFP_KERNEL);
60
61 if (unlikely(child == NULL)) {
62 spin_lock(&mm->unused_lock);
63 if (list_empty(&mm->unused_nodes))
64 child = NULL;
65 else {
66 child =
67 list_entry(mm->unused_nodes.next,
68 struct drm_mm_node, node_list);
69 list_del(&child->node_list);
70 --mm->num_unused;
71 }
72 spin_unlock(&mm->unused_lock);
73 }
74 return child;
75}
76
77/* drm_mm_pre_get() - pre allocate drm_mm_node structure
78 * drm_mm: memory manager struct we are pre-allocating for
79 *
80 * Returns 0 on success or -ENOMEM if allocation fails.
81 */
82int drm_mm_pre_get(struct drm_mm *mm)
83{
84 struct drm_mm_node *node;
85
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);
91
92 if (unlikely(node == NULL)) {
93 int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
94 spin_unlock(&mm->unused_lock);
95 return ret;
96 }
97 ++mm->num_unused;
98 list_add_tail(&node->node_list, &mm->unused_nodes);
99 }
100 spin_unlock(&mm->unused_lock);
101 return 0;
102}
103EXPORT_SYMBOL(drm_mm_pre_get);
104
105static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
106{
107 return hole_node->start + hole_node->size;
108}
109
110static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
111{
112 struct drm_mm_node *next_node =
113 list_entry(hole_node->node_list.next, struct drm_mm_node,
114 node_list);
115
116 return next_node->start;
117}
118
119static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
120 struct drm_mm_node *node,
121 unsigned long size, unsigned alignment)
122{
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);
127
128 BUG_ON(!hole_node->hole_follows || node->allocated);
129
130 if (alignment)
131 tmp = hole_start % alignment;
132
133 if (!tmp) {
134 hole_node->hole_follows = 0;
135 list_del_init(&hole_node->hole_stack);
136 } else
137 wasted = alignment - tmp;
138
139 node->start = hole_start + wasted;
140 node->size = size;
141 node->mm = mm;
142 node->allocated = 1;
143
144 INIT_LIST_HEAD(&node->hole_stack);
145 list_add(&node->node_list, &hole_node->node_list);
146
147 BUG_ON(node->start + node->size > hole_end);
148
149 if (node->start + node->size < hole_end) {
150 list_add(&node->hole_stack, &mm->hole_stack);
151 node->hole_follows = 1;
152 } else {
153 node->hole_follows = 0;
154 }
155}
156
157struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
158 unsigned long size,
159 unsigned alignment,
160 int atomic)
161{
162 struct drm_mm_node *node;
163
164 node = drm_mm_kmalloc(hole_node->mm, atomic);
165 if (unlikely(node == NULL))
166 return NULL;
167
168 drm_mm_insert_helper(hole_node, node, size, alignment);
169
170 return node;
171}
172EXPORT_SYMBOL(drm_mm_get_block_generic);
173
174/**
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
177 * must be cleared.
178 */
179int drm_mm_insert_node(struct drm_mm *mm, struct drm_mm_node *node,
180 unsigned long size, unsigned alignment)
181{
182 struct drm_mm_node *hole_node;
183
184 hole_node = drm_mm_search_free(mm, size, alignment, 0);
185 if (!hole_node)
186 return -ENOSPC;
187
188 drm_mm_insert_helper(hole_node, node, size, alignment);
189
190 return 0;
191}
192EXPORT_SYMBOL(drm_mm_insert_node);
193
194static 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)
198{
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);
203
204 BUG_ON(!hole_node->hole_follows || node->allocated);
205
206 if (hole_start < start)
207 wasted += start - hole_start;
208 if (alignment)
209 tmp = (hole_start + wasted) % alignment;
210
211 if (tmp)
212 wasted += alignment - tmp;
213
214 if (!wasted) {
215 hole_node->hole_follows = 0;
216 list_del_init(&hole_node->hole_stack);
217 }
218
219 node->start = hole_start + wasted;
220 node->size = size;
221 node->mm = mm;
222 node->allocated = 1;
223
224 INIT_LIST_HEAD(&node->hole_stack);
225 list_add(&node->node_list, &hole_node->node_list);
226
227 BUG_ON(node->start + node->size > hole_end);
228 BUG_ON(node->start + node->size > end);
229
230 if (node->start + node->size < hole_end) {
231 list_add(&node->hole_stack, &mm->hole_stack);
232 node->hole_follows = 1;
233 } else {
234 node->hole_follows = 0;
235 }
236}
237
238struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
239 unsigned long size,
240 unsigned alignment,
241 unsigned long start,
242 unsigned long end,
243 int atomic)
244{
245 struct drm_mm_node *node;
246
247 node = drm_mm_kmalloc(hole_node->mm, atomic);
248 if (unlikely(node == NULL))
249 return NULL;
250
251 drm_mm_insert_helper_range(hole_node, node, size, alignment,
252 start, end);
253
254 return node;
255}
256EXPORT_SYMBOL(drm_mm_get_block_range_generic);
257
258/**
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.
262 */
263int 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)
266{
267 struct drm_mm_node *hole_node;
268
269 hole_node = drm_mm_search_free_in_range(mm, size, alignment,
270 start, end, 0);
271 if (!hole_node)
272 return -ENOSPC;
273
274 drm_mm_insert_helper_range(hole_node, node, size, alignment,
275 start, end);
276
277 return 0;
278}
279EXPORT_SYMBOL(drm_mm_insert_node_in_range);
280
281/**
282 * Remove a memory node from the allocator.
283 */
284void drm_mm_remove_node(struct drm_mm_node *node)
285{
286 struct drm_mm *mm = node->mm;
287 struct drm_mm_node *prev_node;
288
289 BUG_ON(node->scanned_block || node->scanned_prev_free
290 || node->scanned_next_free);
291
292 prev_node =
293 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
294
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);
299 } else
300 BUG_ON(drm_mm_hole_node_start(node)
301 != drm_mm_hole_node_end(node));
302
303 if (!prev_node->hole_follows) {
304 prev_node->hole_follows = 1;
305 list_add(&prev_node->hole_stack, &mm->hole_stack);
306 } else
307 list_move(&prev_node->hole_stack, &mm->hole_stack);
308
309 list_del(&node->node_list);
310 node->allocated = 0;
311}
312EXPORT_SYMBOL(drm_mm_remove_node);
313
314/*
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.
318 */
319void drm_mm_put_block(struct drm_mm_node *node)
320{
321
322 struct drm_mm *mm = node->mm;
323
324 drm_mm_remove_node(node);
325
326 spin_lock(&mm->unused_lock);
327 if (mm->num_unused < MM_UNUSED_TARGET) {
328 list_add(&node->node_list, &mm->unused_nodes);
329 ++mm->num_unused;
330 } else
331 kfree(node);
332 spin_unlock(&mm->unused_lock);
333}
334EXPORT_SYMBOL(drm_mm_put_block);
335
336static int check_free_hole(unsigned long start, unsigned long end,
337 unsigned long size, unsigned alignment)
338{
339 unsigned wasted = 0;
340
341 if (end - start < size)
342 return 0;
343
344 if (alignment) {
345 unsigned tmp = start % alignment;
346 if (tmp)
347 wasted = alignment - tmp;
348 }
349
350 if (end >= start + size + wasted) {
351 return 1;
352 }
353
354 return 0;
355}
356
357struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
358 unsigned long size,
359 unsigned alignment, int best_match)
360{
361 struct drm_mm_node *entry;
362 struct drm_mm_node *best;
363 unsigned long best_size;
364
365 BUG_ON(mm->scanned_blocks);
366
367 best = NULL;
368 best_size = ~0UL;
369
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),
374 size, alignment))
375 continue;
376
377 if (!best_match)
378 return entry;
379
380 if (entry->size < best_size) {
381 best = entry;
382 best_size = entry->size;
383 }
384 }
385
386 return best;
387}
388EXPORT_SYMBOL(drm_mm_search_free);
389
390struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
391 unsigned long size,
392 unsigned alignment,
393 unsigned long start,
394 unsigned long end,
395 int best_match)
396{
397 struct drm_mm_node *entry;
398 struct drm_mm_node *best;
399 unsigned long best_size;
400
401 BUG_ON(mm->scanned_blocks);
402
403 best = NULL;
404 best_size = ~0UL;
405
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);
411
412 BUG_ON(!entry->hole_follows);
413 if (!check_free_hole(adj_start, adj_end, size, alignment))
414 continue;
415
416 if (!best_match)
417 return entry;
418
419 if (entry->size < best_size) {
420 best = entry;
421 best_size = entry->size;
422 }
423 }
424
425 return best;
426}
427EXPORT_SYMBOL(drm_mm_search_free_in_range);
428
429/**
430 * Moves an allocation. To be used with embedded struct drm_mm_node.
431 */
432void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
433{
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;
437 new->mm = old->mm;
438 new->start = old->start;
439 new->size = old->size;
440
441 old->allocated = 0;
442 new->allocated = 1;
443}
444EXPORT_SYMBOL(drm_mm_replace_node);
445
446/**
447 * Initializa lru scanning.
448 *
449 * This simply sets up the scanning routines with the parameters for the desired
450 * hole.
451 *
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.
454 */
455void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
456 unsigned alignment)
457{
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;
465}
466EXPORT_SYMBOL(drm_mm_init_scan);
467
468/**
469 * Initializa lru scanning.
470 *
471 * This simply sets up the scanning routines with the parameters for the desired
472 * hole. This version is for range-restricted scans.
473 *
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.
476 */
477void drm_mm_init_scan_with_range(struct drm_mm *mm, unsigned long size,
478 unsigned alignment,
479 unsigned long start,
480 unsigned long end)
481{
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;
488 mm->scan_end = end;
489 mm->scan_check_range = 1;
490 mm->prev_scanned_node = NULL;
491}
492EXPORT_SYMBOL(drm_mm_init_scan_with_range);
493
494/**
495 * Add a node to the scan list that might be freed to make space for the desired
496 * hole.
497 *
498 * Returns non-zero, if a hole has been found, zero otherwise.
499 */
500int drm_mm_scan_add_block(struct drm_mm_node *node)
501{
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;
507
508 mm->scanned_blocks++;
509
510 BUG_ON(node->scanned_block);
511 node->scanned_block = 1;
512
513 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
514 node_list);
515
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;
522
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;
530 } else {
531 adj_start = hole_start;
532 adj_end = hole_end;
533 }
534
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;
539
540 return 1;
541 }
542
543 return 0;
544}
545EXPORT_SYMBOL(drm_mm_scan_add_block);
546
547/**
548 * Remove a node from the scan list.
549 *
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
552 * corrupted.
553 *
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).
557 *
558 * Returns one if this block should be evicted, zero otherwise. Will always
559 * return zero when no hole has been found.
560 */
561int drm_mm_scan_remove_block(struct drm_mm_node *node)
562{
563 struct drm_mm *mm = node->mm;
564 struct drm_mm_node *prev_node;
565
566 mm->scanned_blocks--;
567
568 BUG_ON(!node->scanned_block);
569 node->scanned_block = 0;
570
571 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
572 node_list);
573
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);
577
578 /* Only need to check for containement because start&size for the
579 * complete resulting free block (not just the desired part) is
580 * stored. */
581 if (node->start >= mm->scan_hit_start &&
582 node->start + node->size
583 <= mm->scan_hit_start + mm->scan_hit_size) {
584 return 1;
585 }
586
587 return 0;
588}
589EXPORT_SYMBOL(drm_mm_scan_remove_block);
590
591int drm_mm_clean(struct drm_mm * mm)
592{
593 struct list_head *head = &mm->head_node.node_list;
594
595 return (head->next->next == head);
596}
597EXPORT_SYMBOL(drm_mm_clean);
598
599int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
600{
601 INIT_LIST_HEAD(&mm->hole_stack);
602 INIT_LIST_HEAD(&mm->unused_nodes);
603 mm->num_unused = 0;
604 mm->scanned_blocks = 0;
605 spin_lock_init(&mm->unused_lock);
606
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);
618
619 return 0;
620}
621EXPORT_SYMBOL(drm_mm_init);
622
623void drm_mm_takedown(struct drm_mm * mm)
624{
625 struct drm_mm_node *entry, *next;
626
627 if (!list_empty(&mm->head_node.node_list)) {
628 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
629 return;
630 }
631
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);
635 kfree(entry);
636 --mm->num_unused;
637 }
638 spin_unlock(&mm->unused_lock);
639
640 BUG_ON(mm->num_unused != 0);
641}
642EXPORT_SYMBOL(drm_mm_takedown);
643
644void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
645{
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;
649
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;
653 if (hole_size)
654 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
655 prefix, hole_start, hole_end,
656 hole_size);
657 total_free += hole_size;
658
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,
662 entry->size);
663 total_used += entry->size;
664
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,
671 hole_size);
672 total_free += hole_size;
673 }
674 }
675 total = total_free + total_used;
676
677 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
678 total_used, total_free);
679}
680EXPORT_SYMBOL(drm_mm_debug_table);
681
682#if defined(CONFIG_DEBUG_FS)
683int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
684{
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;
688
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;
692 if (hole_size)
693 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
694 hole_start, hole_end, hole_size);
695 total_free += hole_size;
696
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,
700 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;
709 }
710 }
711 total = total_free + total_used;
712
713 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
714 return 0;
715}
716EXPORT_SYMBOL(drm_mm_dump_table);
717#endif