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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 <drm/drmP.h>
45#include <drm/drm_mm.h>
46#include <linux/slab.h>
47#include <linux/seq_file.h>
48#include <linux/export.h>
49
50/**
51 * DOC: Overview
52 *
53 * drm_mm provides a simple range allocator. The drivers are free to use the
54 * resource allocator from the linux core if it suits them, the upside of drm_mm
55 * is that it's in the DRM core. Which means that it's easier to extend for
56 * some of the crazier special purpose needs of gpus.
57 *
58 * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node.
59 * Drivers are free to embed either of them into their own suitable
60 * datastructures. drm_mm itself will not do any allocations of its own, so if
61 * drivers choose not to embed nodes they need to still allocate them
62 * themselves.
63 *
64 * The range allocator also supports reservation of preallocated blocks. This is
65 * useful for taking over initial mode setting configurations from the firmware,
66 * where an object needs to be created which exactly matches the firmware's
67 * scanout target. As long as the range is still free it can be inserted anytime
68 * after the allocator is initialized, which helps with avoiding looped
69 * depencies in the driver load sequence.
70 *
71 * drm_mm maintains a stack of most recently freed holes, which of all
72 * simplistic datastructures seems to be a fairly decent approach to clustering
73 * allocations and avoiding too much fragmentation. This means free space
74 * searches are O(num_holes). Given that all the fancy features drm_mm supports
75 * something better would be fairly complex and since gfx thrashing is a fairly
76 * steep cliff not a real concern. Removing a node again is O(1).
77 *
78 * drm_mm supports a few features: Alignment and range restrictions can be
79 * supplied. Further more every &drm_mm_node has a color value (which is just an
80 * opaqua unsigned long) which in conjunction with a driver callback can be used
81 * to implement sophisticated placement restrictions. The i915 DRM driver uses
82 * this to implement guard pages between incompatible caching domains in the
83 * graphics TT.
84 *
85 * Two behaviors are supported for searching and allocating: bottom-up and top-down.
86 * The default is bottom-up. Top-down allocation can be used if the memory area
87 * has different restrictions, or just to reduce fragmentation.
88 *
89 * Finally iteration helpers to walk all nodes and all holes are provided as are
90 * some basic allocator dumpers for debugging.
91 */
92
93static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
94 unsigned long size,
95 unsigned alignment,
96 unsigned long color,
97 enum drm_mm_search_flags flags);
98static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
99 unsigned long size,
100 unsigned alignment,
101 unsigned long color,
102 unsigned long start,
103 unsigned long end,
104 enum drm_mm_search_flags flags);
105
106static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
107 struct drm_mm_node *node,
108 unsigned long size, unsigned alignment,
109 unsigned long color,
110 enum drm_mm_allocator_flags flags)
111{
112 struct drm_mm *mm = hole_node->mm;
113 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
114 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
115 unsigned long adj_start = hole_start;
116 unsigned long adj_end = hole_end;
117
118 BUG_ON(node->allocated);
119
120 if (mm->color_adjust)
121 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
122
123 if (flags & DRM_MM_CREATE_TOP)
124 adj_start = adj_end - size;
125
126 if (alignment) {
127 unsigned tmp = adj_start % alignment;
128 if (tmp) {
129 if (flags & DRM_MM_CREATE_TOP)
130 adj_start -= tmp;
131 else
132 adj_start += alignment - tmp;
133 }
134 }
135
136 BUG_ON(adj_start < hole_start);
137 BUG_ON(adj_end > hole_end);
138
139 if (adj_start == hole_start) {
140 hole_node->hole_follows = 0;
141 list_del(&hole_node->hole_stack);
142 }
143
144 node->start = adj_start;
145 node->size = size;
146 node->mm = mm;
147 node->color = color;
148 node->allocated = 1;
149
150 INIT_LIST_HEAD(&node->hole_stack);
151 list_add(&node->node_list, &hole_node->node_list);
152
153 BUG_ON(node->start + node->size > adj_end);
154
155 node->hole_follows = 0;
156 if (__drm_mm_hole_node_start(node) < hole_end) {
157 list_add(&node->hole_stack, &mm->hole_stack);
158 node->hole_follows = 1;
159 }
160}
161
162/**
163 * drm_mm_reserve_node - insert an pre-initialized node
164 * @mm: drm_mm allocator to insert @node into
165 * @node: drm_mm_node to insert
166 *
167 * This functions inserts an already set-up drm_mm_node into the allocator,
168 * meaning that start, size and color must be set by the caller. This is useful
169 * to initialize the allocator with preallocated objects which must be set-up
170 * before the range allocator can be set-up, e.g. when taking over a firmware
171 * framebuffer.
172 *
173 * Returns:
174 * 0 on success, -ENOSPC if there's no hole where @node is.
175 */
176int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
177{
178 struct drm_mm_node *hole;
179 unsigned long end = node->start + node->size;
180 unsigned long hole_start;
181 unsigned long hole_end;
182
183 BUG_ON(node == NULL);
184
185 /* Find the relevant hole to add our node to */
186 drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
187 if (hole_start > node->start || hole_end < end)
188 continue;
189
190 node->mm = mm;
191 node->allocated = 1;
192
193 INIT_LIST_HEAD(&node->hole_stack);
194 list_add(&node->node_list, &hole->node_list);
195
196 if (node->start == hole_start) {
197 hole->hole_follows = 0;
198 list_del_init(&hole->hole_stack);
199 }
200
201 node->hole_follows = 0;
202 if (end != hole_end) {
203 list_add(&node->hole_stack, &mm->hole_stack);
204 node->hole_follows = 1;
205 }
206
207 return 0;
208 }
209
210 return -ENOSPC;
211}
212EXPORT_SYMBOL(drm_mm_reserve_node);
213
214/**
215 * drm_mm_insert_node_generic - search for space and insert @node
216 * @mm: drm_mm to allocate from
217 * @node: preallocate node to insert
218 * @size: size of the allocation
219 * @alignment: alignment of the allocation
220 * @color: opaque tag value to use for this node
221 * @sflags: flags to fine-tune the allocation search
222 * @aflags: flags to fine-tune the allocation behavior
223 *
224 * The preallocated node must be cleared to 0.
225 *
226 * Returns:
227 * 0 on success, -ENOSPC if there's no suitable hole.
228 */
229int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
230 unsigned long size, unsigned alignment,
231 unsigned long color,
232 enum drm_mm_search_flags sflags,
233 enum drm_mm_allocator_flags aflags)
234{
235 struct drm_mm_node *hole_node;
236
237 hole_node = drm_mm_search_free_generic(mm, size, alignment,
238 color, sflags);
239 if (!hole_node)
240 return -ENOSPC;
241
242 drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags);
243 return 0;
244}
245EXPORT_SYMBOL(drm_mm_insert_node_generic);
246
247static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
248 struct drm_mm_node *node,
249 unsigned long size, unsigned alignment,
250 unsigned long color,
251 unsigned long start, unsigned long end,
252 enum drm_mm_allocator_flags flags)
253{
254 struct drm_mm *mm = hole_node->mm;
255 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
256 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
257 unsigned long adj_start = hole_start;
258 unsigned long adj_end = hole_end;
259
260 BUG_ON(!hole_node->hole_follows || node->allocated);
261
262 if (adj_start < start)
263 adj_start = start;
264 if (adj_end > end)
265 adj_end = end;
266
267 if (flags & DRM_MM_CREATE_TOP)
268 adj_start = adj_end - size;
269
270 if (mm->color_adjust)
271 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
272
273 if (alignment) {
274 unsigned tmp = adj_start % alignment;
275 if (tmp) {
276 if (flags & DRM_MM_CREATE_TOP)
277 adj_start -= tmp;
278 else
279 adj_start += alignment - tmp;
280 }
281 }
282
283 if (adj_start == hole_start) {
284 hole_node->hole_follows = 0;
285 list_del(&hole_node->hole_stack);
286 }
287
288 node->start = adj_start;
289 node->size = size;
290 node->mm = mm;
291 node->color = color;
292 node->allocated = 1;
293
294 INIT_LIST_HEAD(&node->hole_stack);
295 list_add(&node->node_list, &hole_node->node_list);
296
297 BUG_ON(node->start < start);
298 BUG_ON(node->start < adj_start);
299 BUG_ON(node->start + node->size > adj_end);
300 BUG_ON(node->start + node->size > end);
301
302 node->hole_follows = 0;
303 if (__drm_mm_hole_node_start(node) < hole_end) {
304 list_add(&node->hole_stack, &mm->hole_stack);
305 node->hole_follows = 1;
306 }
307}
308
309/**
310 * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node
311 * @mm: drm_mm to allocate from
312 * @node: preallocate node to insert
313 * @size: size of the allocation
314 * @alignment: alignment of the allocation
315 * @color: opaque tag value to use for this node
316 * @start: start of the allowed range for this node
317 * @end: end of the allowed range for this node
318 * @sflags: flags to fine-tune the allocation search
319 * @aflags: flags to fine-tune the allocation behavior
320 *
321 * The preallocated node must be cleared to 0.
322 *
323 * Returns:
324 * 0 on success, -ENOSPC if there's no suitable hole.
325 */
326int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
327 unsigned long size, unsigned alignment,
328 unsigned long color,
329 unsigned long start, unsigned long end,
330 enum drm_mm_search_flags sflags,
331 enum drm_mm_allocator_flags aflags)
332{
333 struct drm_mm_node *hole_node;
334
335 hole_node = drm_mm_search_free_in_range_generic(mm,
336 size, alignment, color,
337 start, end, sflags);
338 if (!hole_node)
339 return -ENOSPC;
340
341 drm_mm_insert_helper_range(hole_node, node,
342 size, alignment, color,
343 start, end, aflags);
344 return 0;
345}
346EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
347
348/**
349 * drm_mm_remove_node - Remove a memory node from the allocator.
350 * @node: drm_mm_node to remove
351 *
352 * This just removes a node from its drm_mm allocator. The node does not need to
353 * be cleared again before it can be re-inserted into this or any other drm_mm
354 * allocator. It is a bug to call this function on a un-allocated node.
355 */
356void drm_mm_remove_node(struct drm_mm_node *node)
357{
358 struct drm_mm *mm = node->mm;
359 struct drm_mm_node *prev_node;
360
361 if (WARN_ON(!node->allocated))
362 return;
363
364 BUG_ON(node->scanned_block || node->scanned_prev_free
365 || node->scanned_next_free);
366
367 prev_node =
368 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
369
370 if (node->hole_follows) {
371 BUG_ON(__drm_mm_hole_node_start(node) ==
372 __drm_mm_hole_node_end(node));
373 list_del(&node->hole_stack);
374 } else
375 BUG_ON(__drm_mm_hole_node_start(node) !=
376 __drm_mm_hole_node_end(node));
377
378
379 if (!prev_node->hole_follows) {
380 prev_node->hole_follows = 1;
381 list_add(&prev_node->hole_stack, &mm->hole_stack);
382 } else
383 list_move(&prev_node->hole_stack, &mm->hole_stack);
384
385 list_del(&node->node_list);
386 node->allocated = 0;
387}
388EXPORT_SYMBOL(drm_mm_remove_node);
389
390static int check_free_hole(unsigned long start, unsigned long end,
391 unsigned long size, unsigned alignment)
392{
393 if (end - start < size)
394 return 0;
395
396 if (alignment) {
397 unsigned tmp = start % alignment;
398 if (tmp)
399 start += alignment - tmp;
400 }
401
402 return end >= start + size;
403}
404
405static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
406 unsigned long size,
407 unsigned alignment,
408 unsigned long color,
409 enum drm_mm_search_flags flags)
410{
411 struct drm_mm_node *entry;
412 struct drm_mm_node *best;
413 unsigned long adj_start;
414 unsigned long adj_end;
415 unsigned long best_size;
416
417 BUG_ON(mm->scanned_blocks);
418
419 best = NULL;
420 best_size = ~0UL;
421
422 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
423 flags & DRM_MM_SEARCH_BELOW) {
424 unsigned long hole_size = adj_end - adj_start;
425
426 if (mm->color_adjust) {
427 mm->color_adjust(entry, color, &adj_start, &adj_end);
428 if (adj_end <= adj_start)
429 continue;
430 }
431
432 if (!check_free_hole(adj_start, adj_end, size, alignment))
433 continue;
434
435 if (!(flags & DRM_MM_SEARCH_BEST))
436 return entry;
437
438 if (hole_size < best_size) {
439 best = entry;
440 best_size = hole_size;
441 }
442 }
443
444 return best;
445}
446
447static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
448 unsigned long size,
449 unsigned alignment,
450 unsigned long color,
451 unsigned long start,
452 unsigned long end,
453 enum drm_mm_search_flags flags)
454{
455 struct drm_mm_node *entry;
456 struct drm_mm_node *best;
457 unsigned long adj_start;
458 unsigned long adj_end;
459 unsigned long best_size;
460
461 BUG_ON(mm->scanned_blocks);
462
463 best = NULL;
464 best_size = ~0UL;
465
466 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
467 flags & DRM_MM_SEARCH_BELOW) {
468 unsigned long hole_size = adj_end - adj_start;
469
470 if (adj_start < start)
471 adj_start = start;
472 if (adj_end > end)
473 adj_end = end;
474
475 if (mm->color_adjust) {
476 mm->color_adjust(entry, color, &adj_start, &adj_end);
477 if (adj_end <= adj_start)
478 continue;
479 }
480
481 if (!check_free_hole(adj_start, adj_end, size, alignment))
482 continue;
483
484 if (!(flags & DRM_MM_SEARCH_BEST))
485 return entry;
486
487 if (hole_size < best_size) {
488 best = entry;
489 best_size = hole_size;
490 }
491 }
492
493 return best;
494}
495
496/**
497 * drm_mm_replace_node - move an allocation from @old to @new
498 * @old: drm_mm_node to remove from the allocator
499 * @new: drm_mm_node which should inherit @old's allocation
500 *
501 * This is useful for when drivers embed the drm_mm_node structure and hence
502 * can't move allocations by reassigning pointers. It's a combination of remove
503 * and insert with the guarantee that the allocation start will match.
504 */
505void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
506{
507 list_replace(&old->node_list, &new->node_list);
508 list_replace(&old->hole_stack, &new->hole_stack);
509 new->hole_follows = old->hole_follows;
510 new->mm = old->mm;
511 new->start = old->start;
512 new->size = old->size;
513 new->color = old->color;
514
515 old->allocated = 0;
516 new->allocated = 1;
517}
518EXPORT_SYMBOL(drm_mm_replace_node);
519
520/**
521 * DOC: lru scan roaster
522 *
523 * Very often GPUs need to have continuous allocations for a given object. When
524 * evicting objects to make space for a new one it is therefore not most
525 * efficient when we simply start to select all objects from the tail of an LRU
526 * until there's a suitable hole: Especially for big objects or nodes that
527 * otherwise have special allocation constraints there's a good chance we evict
528 * lots of (smaller) objects unecessarily.
529 *
530 * The DRM range allocator supports this use-case through the scanning
531 * interfaces. First a scan operation needs to be initialized with
532 * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds
533 * objects to the roaster (probably by walking an LRU list, but this can be
534 * freely implemented) until a suitable hole is found or there's no further
535 * evitable object.
536 *
537 * The the driver must walk through all objects again in exactly the reverse
538 * order to restore the allocator state. Note that while the allocator is used
539 * in the scan mode no other operation is allowed.
540 *
541 * Finally the driver evicts all objects selected in the scan. Adding and
542 * removing an object is O(1), and since freeing a node is also O(1) the overall
543 * complexity is O(scanned_objects). So like the free stack which needs to be
544 * walked before a scan operation even begins this is linear in the number of
545 * objects. It doesn't seem to hurt badly.
546 */
547
548/**
549 * drm_mm_init_scan - initialize lru scanning
550 * @mm: drm_mm to scan
551 * @size: size of the allocation
552 * @alignment: alignment of the allocation
553 * @color: opaque tag value to use for the allocation
554 *
555 * This simply sets up the scanning routines with the parameters for the desired
556 * hole. Note that there's no need to specify allocation flags, since they only
557 * change the place a node is allocated from within a suitable hole.
558 *
559 * Warning:
560 * As long as the scan list is non-empty, no other operations than
561 * adding/removing nodes to/from the scan list are allowed.
562 */
563void drm_mm_init_scan(struct drm_mm *mm,
564 unsigned long size,
565 unsigned alignment,
566 unsigned long color)
567{
568 mm->scan_color = color;
569 mm->scan_alignment = alignment;
570 mm->scan_size = size;
571 mm->scanned_blocks = 0;
572 mm->scan_hit_start = 0;
573 mm->scan_hit_end = 0;
574 mm->scan_check_range = 0;
575 mm->prev_scanned_node = NULL;
576}
577EXPORT_SYMBOL(drm_mm_init_scan);
578
579/**
580 * drm_mm_init_scan - initialize range-restricted lru scanning
581 * @mm: drm_mm to scan
582 * @size: size of the allocation
583 * @alignment: alignment of the allocation
584 * @color: opaque tag value to use for the allocation
585 * @start: start of the allowed range for the allocation
586 * @end: end of the allowed range for the allocation
587 *
588 * This simply sets up the scanning routines with the parameters for the desired
589 * hole. Note that there's no need to specify allocation flags, since they only
590 * change the place a node is allocated from within a suitable hole.
591 *
592 * Warning:
593 * As long as the scan list is non-empty, no other operations than
594 * adding/removing nodes to/from the scan list are allowed.
595 */
596void drm_mm_init_scan_with_range(struct drm_mm *mm,
597 unsigned long size,
598 unsigned alignment,
599 unsigned long color,
600 unsigned long start,
601 unsigned long end)
602{
603 mm->scan_color = color;
604 mm->scan_alignment = alignment;
605 mm->scan_size = size;
606 mm->scanned_blocks = 0;
607 mm->scan_hit_start = 0;
608 mm->scan_hit_end = 0;
609 mm->scan_start = start;
610 mm->scan_end = end;
611 mm->scan_check_range = 1;
612 mm->prev_scanned_node = NULL;
613}
614EXPORT_SYMBOL(drm_mm_init_scan_with_range);
615
616/**
617 * drm_mm_scan_add_block - add a node to the scan list
618 * @node: drm_mm_node to add
619 *
620 * Add a node to the scan list that might be freed to make space for the desired
621 * hole.
622 *
623 * Returns:
624 * True if a hole has been found, false otherwise.
625 */
626bool drm_mm_scan_add_block(struct drm_mm_node *node)
627{
628 struct drm_mm *mm = node->mm;
629 struct drm_mm_node *prev_node;
630 unsigned long hole_start, hole_end;
631 unsigned long adj_start, adj_end;
632
633 mm->scanned_blocks++;
634
635 BUG_ON(node->scanned_block);
636 node->scanned_block = 1;
637
638 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
639 node_list);
640
641 node->scanned_preceeds_hole = prev_node->hole_follows;
642 prev_node->hole_follows = 1;
643 list_del(&node->node_list);
644 node->node_list.prev = &prev_node->node_list;
645 node->node_list.next = &mm->prev_scanned_node->node_list;
646 mm->prev_scanned_node = node;
647
648 adj_start = hole_start = drm_mm_hole_node_start(prev_node);
649 adj_end = hole_end = drm_mm_hole_node_end(prev_node);
650
651 if (mm->scan_check_range) {
652 if (adj_start < mm->scan_start)
653 adj_start = mm->scan_start;
654 if (adj_end > mm->scan_end)
655 adj_end = mm->scan_end;
656 }
657
658 if (mm->color_adjust)
659 mm->color_adjust(prev_node, mm->scan_color,
660 &adj_start, &adj_end);
661
662 if (check_free_hole(adj_start, adj_end,
663 mm->scan_size, mm->scan_alignment)) {
664 mm->scan_hit_start = hole_start;
665 mm->scan_hit_end = hole_end;
666 return true;
667 }
668
669 return false;
670}
671EXPORT_SYMBOL(drm_mm_scan_add_block);
672
673/**
674 * drm_mm_scan_remove_block - remove a node from the scan list
675 * @node: drm_mm_node to remove
676 *
677 * Nodes _must_ be removed in the exact same order from the scan list as they
678 * have been added, otherwise the internal state of the memory manager will be
679 * corrupted.
680 *
681 * When the scan list is empty, the selected memory nodes can be freed. An
682 * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then
683 * return the just freed block (because its at the top of the free_stack list).
684 *
685 * Returns:
686 * True if this block should be evicted, false otherwise. Will always
687 * return false when no hole has been found.
688 */
689bool drm_mm_scan_remove_block(struct drm_mm_node *node)
690{
691 struct drm_mm *mm = node->mm;
692 struct drm_mm_node *prev_node;
693
694 mm->scanned_blocks--;
695
696 BUG_ON(!node->scanned_block);
697 node->scanned_block = 0;
698
699 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
700 node_list);
701
702 prev_node->hole_follows = node->scanned_preceeds_hole;
703 list_add(&node->node_list, &prev_node->node_list);
704
705 return (drm_mm_hole_node_end(node) > mm->scan_hit_start &&
706 node->start < mm->scan_hit_end);
707}
708EXPORT_SYMBOL(drm_mm_scan_remove_block);
709
710/**
711 * drm_mm_clean - checks whether an allocator is clean
712 * @mm: drm_mm allocator to check
713 *
714 * Returns:
715 * True if the allocator is completely free, false if there's still a node
716 * allocated in it.
717 */
718bool drm_mm_clean(struct drm_mm * mm)
719{
720 struct list_head *head = &mm->head_node.node_list;
721
722 return (head->next->next == head);
723}
724EXPORT_SYMBOL(drm_mm_clean);
725
726/**
727 * drm_mm_init - initialize a drm-mm allocator
728 * @mm: the drm_mm structure to initialize
729 * @start: start of the range managed by @mm
730 * @size: end of the range managed by @mm
731 *
732 * Note that @mm must be cleared to 0 before calling this function.
733 */
734void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
735{
736 INIT_LIST_HEAD(&mm->hole_stack);
737 mm->scanned_blocks = 0;
738
739 /* Clever trick to avoid a special case in the free hole tracking. */
740 INIT_LIST_HEAD(&mm->head_node.node_list);
741 INIT_LIST_HEAD(&mm->head_node.hole_stack);
742 mm->head_node.hole_follows = 1;
743 mm->head_node.scanned_block = 0;
744 mm->head_node.scanned_prev_free = 0;
745 mm->head_node.scanned_next_free = 0;
746 mm->head_node.mm = mm;
747 mm->head_node.start = start + size;
748 mm->head_node.size = start - mm->head_node.start;
749 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
750
751 mm->color_adjust = NULL;
752}
753EXPORT_SYMBOL(drm_mm_init);
754
755/**
756 * drm_mm_takedown - clean up a drm_mm allocator
757 * @mm: drm_mm allocator to clean up
758 *
759 * Note that it is a bug to call this function on an allocator which is not
760 * clean.
761 */
762void drm_mm_takedown(struct drm_mm * mm)
763{
764 WARN(!list_empty(&mm->head_node.node_list),
765 "Memory manager not clean during takedown.\n");
766}
767EXPORT_SYMBOL(drm_mm_takedown);
768
769static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry,
770 const char *prefix)
771{
772 unsigned long hole_start, hole_end, hole_size;
773
774 if (entry->hole_follows) {
775 hole_start = drm_mm_hole_node_start(entry);
776 hole_end = drm_mm_hole_node_end(entry);
777 hole_size = hole_end - hole_start;
778 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
779 prefix, hole_start, hole_end,
780 hole_size);
781 return hole_size;
782 }
783
784 return 0;
785}
786
787/**
788 * drm_mm_debug_table - dump allocator state to dmesg
789 * @mm: drm_mm allocator to dump
790 * @prefix: prefix to use for dumping to dmesg
791 */
792void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
793{
794 struct drm_mm_node *entry;
795 unsigned long total_used = 0, total_free = 0, total = 0;
796
797 total_free += drm_mm_debug_hole(&mm->head_node, prefix);
798
799 drm_mm_for_each_node(entry, mm) {
800 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
801 prefix, entry->start, entry->start + entry->size,
802 entry->size);
803 total_used += entry->size;
804 total_free += drm_mm_debug_hole(entry, prefix);
805 }
806 total = total_free + total_used;
807
808 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
809 total_used, total_free);
810}
811EXPORT_SYMBOL(drm_mm_debug_table);
812
813#if defined(CONFIG_DEBUG_FS)
814static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
815{
816 unsigned long hole_start, hole_end, hole_size;
817
818 if (entry->hole_follows) {
819 hole_start = drm_mm_hole_node_start(entry);
820 hole_end = drm_mm_hole_node_end(entry);
821 hole_size = hole_end - hole_start;
822 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
823 hole_start, hole_end, hole_size);
824 return hole_size;
825 }
826
827 return 0;
828}
829
830/**
831 * drm_mm_dump_table - dump allocator state to a seq_file
832 * @m: seq_file to dump to
833 * @mm: drm_mm allocator to dump
834 */
835int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
836{
837 struct drm_mm_node *entry;
838 unsigned long total_used = 0, total_free = 0, total = 0;
839
840 total_free += drm_mm_dump_hole(m, &mm->head_node);
841
842 drm_mm_for_each_node(entry, mm) {
843 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
844 entry->start, entry->start + entry->size,
845 entry->size);
846 total_used += entry->size;
847 total_free += drm_mm_dump_hole(m, entry);
848 }
849 total = total_free + total_used;
850
851 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
852 return 0;
853}
854EXPORT_SYMBOL(drm_mm_dump_table);
855#endif