aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/drm_mm.c
blob: 07cf99cc886283aedf9feee690d71ee6fbe2fb77 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
/**************************************************************************
 *
 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 *
 **************************************************************************/

/*
 * Generic simple memory manager implementation. Intended to be used as a base
 * class implementation for more advanced memory managers.
 *
 * Note that the algorithm used is quite simple and there might be substantial
 * performance gains if a smarter free list is implemented. Currently it is just an
 * unordered stack of free regions. This could easily be improved if an RB-tree
 * is used instead. At least if we expect heavy fragmentation.
 *
 * Aligned allocations can also see improvement.
 *
 * Authors:
 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 */

#include <drm/drmP.h>
#include <drm/drm_mm.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/export.h>

#define MM_UNUSED_TARGET 4

static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
{
	struct drm_mm_node *child;

	if (atomic)
		child = kzalloc(sizeof(*child), GFP_ATOMIC);
	else
		child = kzalloc(sizeof(*child), GFP_KERNEL);

	if (unlikely(child == NULL)) {
		spin_lock(&mm->unused_lock);
		if (list_empty(&mm->unused_nodes))
			child = NULL;
		else {
			child =
			    list_entry(mm->unused_nodes.next,
				       struct drm_mm_node, node_list);
			list_del(&child->node_list);
			--mm->num_unused;
		}
		spin_unlock(&mm->unused_lock);
	}
	return child;
}

/* drm_mm_pre_get() - pre allocate drm_mm_node structure
 * drm_mm:	memory manager struct we are pre-allocating for
 *
 * Returns 0 on success or -ENOMEM if allocation fails.
 */
int drm_mm_pre_get(struct drm_mm *mm)
{
	struct drm_mm_node *node;

	spin_lock(&mm->unused_lock);
	while (mm->num_unused < MM_UNUSED_TARGET) {
		spin_unlock(&mm->unused_lock);
		node = kzalloc(sizeof(*node), GFP_KERNEL);
		spin_lock(&mm->unused_lock);

		if (unlikely(node == NULL)) {
			int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
			spin_unlock(&mm->unused_lock);
			return ret;
		}
		++mm->num_unused;
		list_add_tail(&node->node_list, &mm->unused_nodes);
	}
	spin_unlock(&mm->unused_lock);
	return 0;
}
EXPORT_SYMBOL(drm_mm_pre_get);

static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
				 struct drm_mm_node *node,
				 unsigned long size, unsigned alignment,
				 unsigned long color)
{
	struct drm_mm *mm = hole_node->mm;
	unsigned long hole_start = drm_mm_hole_node_start(hole_node);
	unsigned long hole_end = drm_mm_hole_node_end(hole_node);
	unsigned long adj_start = hole_start;
	unsigned long adj_end = hole_end;

	BUG_ON(node->allocated);

	if (mm->color_adjust)
		mm->color_adjust(hole_node, color, &adj_start, &adj_end);

	if (alignment) {
		unsigned tmp = adj_start % alignment;
		if (tmp)
			adj_start += alignment - tmp;
	}

	if (adj_start == hole_start) {
		hole_node->hole_follows = 0;
		list_del(&hole_node->hole_stack);
	}

	node->start = adj_start;
	node->size = size;
	node->mm = mm;
	node->color = color;
	node->allocated = 1;

	INIT_LIST_HEAD(&node->hole_stack);
	list_add(&node->node_list, &hole_node->node_list);

	BUG_ON(node->start + node->size > adj_end);

	node->hole_follows = 0;
	if (__drm_mm_hole_node_start(node) < hole_end) {
		list_add(&node->hole_stack, &mm->hole_stack);
		node->hole_follows = 1;
	}
}

struct drm_mm_node *drm_mm_create_block(struct drm_mm *mm,
					unsigned long start,
					unsigned long size,
					bool atomic)
{
	struct drm_mm_node *hole, *node;
	unsigned long end = start + size;
	unsigned long hole_start;
	unsigned long hole_end;

	drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
		if (hole_start > start || hole_end < end)
			continue;

		node = drm_mm_kmalloc(mm, atomic);
		if (unlikely(node == NULL))
			return NULL;

		node->start = start;
		node->size = size;
		node->mm = mm;
		node->allocated = 1;

		INIT_LIST_HEAD(&node->hole_stack);
		list_add(&node->node_list, &hole->node_list);

		if (start == hole_start) {
			hole->hole_follows = 0;
			list_del_init(&hole->hole_stack);
		}

		node->hole_follows = 0;
		if (end != hole_end) {
			list_add(&node->hole_stack, &mm->hole_stack);
			node->hole_follows = 1;
		}

		return node;
	}

	WARN(1, "no hole found for block 0x%lx + 0x%lx\n", start, size);
	return NULL;
}
EXPORT_SYMBOL(drm_mm_create_block);

struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
					     unsigned long size,
					     unsigned alignment,
					     unsigned long color,
					     int atomic)
{
	struct drm_mm_node *node;

	node = drm_mm_kmalloc(hole_node->mm, atomic);
	if (unlikely(node == NULL))
		return NULL;

	drm_mm_insert_helper(hole_node, node, size, alignment, color);

	return node;
}
EXPORT_SYMBOL(drm_mm_get_block_generic);

/**
 * Search for free space and insert a preallocated memory node. Returns
 * -ENOSPC if no suitable free area is available. The preallocated memory node
 * must be cleared.
 */
int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
			       unsigned long size, unsigned alignment,
			       unsigned long color)
{
	struct drm_mm_node *hole_node;

	hole_node = drm_mm_search_free_generic(mm, size, alignment,
					       color, 0);
	if (!hole_node)
		return -ENOSPC;

	drm_mm_insert_helper(hole_node, node, size, alignment, color);
	return 0;
}
EXPORT_SYMBOL(drm_mm_insert_node_generic);

int drm_mm_insert_node(struct drm_mm *mm, struct drm_mm_node *node,
		       unsigned long size, unsigned alignment)
{
	return drm_mm_insert_node_generic(mm, node, size, alignment, 0);
}
EXPORT_SYMBOL(drm_mm_insert_node);

static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
				       struct drm_mm_node *node,
				       unsigned long size, unsigned alignment,
				       unsigned long color,
				       unsigned long start, unsigned long end)
{
	struct drm_mm *mm = hole_node->mm;
	unsigned long hole_start = drm_mm_hole_node_start(hole_node);
	unsigned long hole_end = drm_mm_hole_node_end(hole_node);
	unsigned long adj_start = hole_start;
	unsigned long adj_end = hole_end;

	BUG_ON(!hole_node->hole_follows || node->allocated);

	if (adj_start < start)
		adj_start = start;
	if (adj_end > end)
		adj_end = end;

	if (mm->color_adjust)
		mm->color_adjust(hole_node, color, &adj_start, &adj_end);

	if (alignment) {
		unsigned tmp = adj_start % alignment;
		if (tmp)
			adj_start += alignment - tmp;
	}

	if (adj_start == hole_start) {
		hole_node->hole_follows = 0;
		list_del(&hole_node->hole_stack);
	}

	node->start = adj_start;
	node->size = size;
	node->mm = mm;
	node->color = color;
	node->allocated = 1;

	INIT_LIST_HEAD(&node->hole_stack);
	list_add(&node->node_list, &hole_node->node_list);

	BUG_ON(node->start + node->size > adj_end);
	BUG_ON(node->start + node->size > end);

	node->hole_follows = 0;
	if (__drm_mm_hole_node_start(node) < hole_end) {
		list_add(&node->hole_stack, &mm->hole_stack);
		node->hole_follows = 1;
	}
}

struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
						unsigned long size,
						unsigned alignment,
						unsigned long color,
						unsigned long start,
						unsigned long end,
						int atomic)
{
	struct drm_mm_node *node;

	node = drm_mm_kmalloc(hole_node->mm, atomic);
	if (unlikely(node == NULL))
		return NULL;

	drm_mm_insert_helper_range(hole_node, node, size, alignment, color,
				   start, end);

	return node;
}
EXPORT_SYMBOL(drm_mm_get_block_range_generic);

/**
 * Search for free space and insert a preallocated memory node. Returns
 * -ENOSPC if no suitable free area is available. This is for range
 * restricted allocations. The preallocated memory node must be cleared.
 */
int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
					unsigned long size, unsigned alignment, unsigned long color,
					unsigned long start, unsigned long end)
{
	struct drm_mm_node *hole_node;

	hole_node = drm_mm_search_free_in_range_generic(mm,
							size, alignment, color,
							start, end, 0);
	if (!hole_node)
		return -ENOSPC;

	drm_mm_insert_helper_range(hole_node, node,
				   size, alignment, color,
				   start, end);
	return 0;
}
EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);

int drm_mm_insert_node_in_range(struct drm_mm *mm, struct drm_mm_node *node,
				unsigned long size, unsigned alignment,
				unsigned long start, unsigned long end)
{
	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment, 0, start, end);
}
EXPORT_SYMBOL(drm_mm_insert_node_in_range);

/**
 * Remove a memory node from the allocator.
 */
void drm_mm_remove_node(struct drm_mm_node *node)
{
	struct drm_mm *mm = node->mm;
	struct drm_mm_node *prev_node;

	BUG_ON(node->scanned_block || node->scanned_prev_free
				   || node->scanned_next_free);

	prev_node =
	    list_entry(node->node_list.prev, struct drm_mm_node, node_list);

	if (node->hole_follows) {
		BUG_ON(__drm_mm_hole_node_start(node) ==
		       __drm_mm_hole_node_end(node));
		list_del(&node->hole_stack);
	} else
		BUG_ON(__drm_mm_hole_node_start(node) !=
		       __drm_mm_hole_node_end(node));


	if (!prev_node->hole_follows) {
		prev_node->hole_follows = 1;
		list_add(&prev_node->hole_stack, &mm->hole_stack);
	} else
		list_move(&prev_node->hole_stack, &mm->hole_stack);

	list_del(&node->node_list);
	node->allocated = 0;
}
EXPORT_SYMBOL(drm_mm_remove_node);

/*
 * Remove a memory node from the allocator and free the allocated struct
 * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
 * drm_mm_get_block functions.
 */
void drm_mm_put_block(struct drm_mm_node *node)
{

	struct drm_mm *mm = node->mm;

	drm_mm_remove_node(node);

	spin_lock(&mm->unused_lock);
	if (mm->num_unused < MM_UNUSED_TARGET) {
		list_add(&node->node_list, &mm->unused_nodes);
		++mm->num_unused;
	} else
		kfree(node);
	spin_unlock(&mm->unused_lock);
}
EXPORT_SYMBOL(drm_mm_put_block);

static int check_free_hole(unsigned long start, unsigned long end,
			   unsigned long size, unsigned alignment)
{
	if (end - start < size)
		return 0;

	if (alignment) {
		unsigned tmp = start % alignment;
		if (tmp)
			start += alignment - tmp;
	}

	return end >= start + size;
}

struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
					       unsigned long size,
					       unsigned alignment,
					       unsigned long color,
					       bool best_match)
{
	struct drm_mm_node *entry;
	struct drm_mm_node *best;
	unsigned long adj_start;
	unsigned long adj_end;
	unsigned long best_size;

	BUG_ON(mm->scanned_blocks);

	best = NULL;
	best_size = ~0UL;

	drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
		if (mm->color_adjust) {
			mm->color_adjust(entry, color, &adj_start, &adj_end);
			if (adj_end <= adj_start)
				continue;
		}

		if (!check_free_hole(adj_start, adj_end, size, alignment))
			continue;

		if (!best_match)
			return entry;

		if (entry->size < best_size) {
			best = entry;
			best_size = entry->size;
		}
	}

	return best;
}
EXPORT_SYMBOL(drm_mm_search_free_generic);

struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
							unsigned long size,
							unsigned alignment,
							unsigned long color,
							unsigned long start,
							unsigned long end,
							bool best_match)
{
	struct drm_mm_node *entry;
	struct drm_mm_node *best;
	unsigned long adj_start;
	unsigned long adj_end;
	unsigned long best_size;

	BUG_ON(mm->scanned_blocks);

	best = NULL;
	best_size = ~0UL;

	drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
		if (adj_start < start)
			adj_start = start;
		if (adj_end > end)
			adj_end = end;

		if (mm->color_adjust) {
			mm->color_adjust(entry, color, &adj_start, &adj_end);
			if (adj_end <= adj_start)
				continue;
		}

		if (!check_free_hole(adj_start, adj_end, size, alignment))
			continue;

		if (!best_match)
			return entry;

		if (entry->size < best_size) {
			best = entry;
			best_size = entry->size;
		}
	}

	return best;
}
EXPORT_SYMBOL(drm_mm_search_free_in_range_generic);

/**
 * Moves an allocation. To be used with embedded struct drm_mm_node.
 */
void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
{
	list_replace(&old->node_list, &new->node_list);
	list_replace(&old->hole_stack, &new->hole_stack);
	new->hole_follows = old->hole_follows;
	new->mm = old->mm;
	new->start = old->start;
	new->size = old->size;
	new->color = old->color;

	old->allocated = 0;
	new->allocated = 1;
}
EXPORT_SYMBOL(drm_mm_replace_node);

/**
 * Initializa lru scanning.
 *
 * This simply sets up the scanning routines with the parameters for the desired
 * hole.
 *
 * Warning: As long as the scan list is non-empty, no other operations than
 * adding/removing nodes to/from the scan list are allowed.
 */
void drm_mm_init_scan(struct drm_mm *mm,
		      unsigned long size,
		      unsigned alignment,
		      unsigned long color)
{
	mm->scan_color = color;
	mm->scan_alignment = alignment;
	mm->scan_size = size;
	mm->scanned_blocks = 0;
	mm->scan_hit_start = 0;
	mm->scan_hit_end = 0;
	mm->scan_check_range = 0;
	mm->prev_scanned_node = NULL;
}
EXPORT_SYMBOL(drm_mm_init_scan);

/**
 * Initializa lru scanning.
 *
 * This simply sets up the scanning routines with the parameters for the desired
 * hole. This version is for range-restricted scans.
 *
 * Warning: As long as the scan list is non-empty, no other operations than
 * adding/removing nodes to/from the scan list are allowed.
 */
void drm_mm_init_scan_with_range(struct drm_mm *mm,
				 unsigned long size,
				 unsigned alignment,
				 unsigned long color,
				 unsigned long start,
				 unsigned long end)
{
	mm->scan_color = color;
	mm->scan_alignment = alignment;
	mm->scan_size = size;
	mm->scanned_blocks = 0;
	mm->scan_hit_start = 0;
	mm->scan_hit_end = 0;
	mm->scan_start = start;
	mm->scan_end = end;
	mm->scan_check_range = 1;
	mm->prev_scanned_node = NULL;
}
EXPORT_SYMBOL(drm_mm_init_scan_with_range);

/**
 * Add a node to the scan list that might be freed to make space for the desired
 * hole.
 *
 * Returns non-zero, if a hole has been found, zero otherwise.
 */
int drm_mm_scan_add_block(struct drm_mm_node *node)
{
	struct drm_mm *mm = node->mm;
	struct drm_mm_node *prev_node;
	unsigned long hole_start, hole_end;
	unsigned long adj_start, adj_end;

	mm->scanned_blocks++;

	BUG_ON(node->scanned_block);
	node->scanned_block = 1;

	prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
			       node_list);

	node->scanned_preceeds_hole = prev_node->hole_follows;
	prev_node->hole_follows = 1;
	list_del(&node->node_list);
	node->node_list.prev = &prev_node->node_list;
	node->node_list.next = &mm->prev_scanned_node->node_list;
	mm->prev_scanned_node = node;

	adj_start = hole_start = drm_mm_hole_node_start(prev_node);
	adj_end = hole_end = drm_mm_hole_node_end(prev_node);

	if (mm->scan_check_range) {
		if (adj_start < mm->scan_start)
			adj_start = mm->scan_start;
		if (adj_end > mm->scan_end)
			adj_end = mm->scan_end;
	}

	if (mm->color_adjust)
		mm->color_adjust(prev_node, mm->scan_color,
				 &adj_start, &adj_end);

	if (check_free_hole(adj_start, adj_end,
			    mm->scan_size, mm->scan_alignment)) {
		mm->scan_hit_start = hole_start;
		mm->scan_hit_end = hole_end;
		return 1;
	}

	return 0;
}
EXPORT_SYMBOL(drm_mm_scan_add_block);

/**
 * Remove a node from the scan list.
 *
 * Nodes _must_ be removed in the exact same order from the scan list as they
 * have been added, otherwise the internal state of the memory manager will be
 * corrupted.
 *
 * When the scan list is empty, the selected memory nodes can be freed. An
 * immediately following drm_mm_search_free with best_match = 0 will then return
 * the just freed block (because its at the top of the free_stack list).
 *
 * Returns one if this block should be evicted, zero otherwise. Will always
 * return zero when no hole has been found.
 */
int drm_mm_scan_remove_block(struct drm_mm_node *node)
{
	struct drm_mm *mm = node->mm;
	struct drm_mm_node *prev_node;

	mm->scanned_blocks--;

	BUG_ON(!node->scanned_block);
	node->scanned_block = 0;

	prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
			       node_list);

	prev_node->hole_follows = node->scanned_preceeds_hole;
	list_add(&node->node_list, &prev_node->node_list);

	 return (drm_mm_hole_node_end(node) > mm->scan_hit_start &&
		 node->start < mm->scan_hit_end);
}
EXPORT_SYMBOL(drm_mm_scan_remove_block);

int drm_mm_clean(struct drm_mm * mm)
{
	struct list_head *head = &mm->head_node.node_list;

	return (head->next->next == head);
}
EXPORT_SYMBOL(drm_mm_clean);

int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
{
	INIT_LIST_HEAD(&mm->hole_stack);
	INIT_LIST_HEAD(&mm->unused_nodes);
	mm->num_unused = 0;
	mm->scanned_blocks = 0;
	spin_lock_init(&mm->unused_lock);

	/* Clever trick to avoid a special case in the free hole tracking. */
	INIT_LIST_HEAD(&mm->head_node.node_list);
	INIT_LIST_HEAD(&mm->head_node.hole_stack);
	mm->head_node.hole_follows = 1;
	mm->head_node.scanned_block = 0;
	mm->head_node.scanned_prev_free = 0;
	mm->head_node.scanned_next_free = 0;
	mm->head_node.mm = mm;
	mm->head_node.start = start + size;
	mm->head_node.size = start - mm->head_node.start;
	list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);

	mm->color_adjust = NULL;

	return 0;
}
EXPORT_SYMBOL(drm_mm_init);

void drm_mm_takedown(struct drm_mm * mm)
{
	struct drm_mm_node *entry, *next;

	if (!list_empty(&mm->head_node.node_list)) {
		DRM_ERROR("Memory manager not clean. Delaying takedown\n");
		return;
	}

	spin_lock(&mm->unused_lock);
	list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
		list_del(&entry->node_list);
		kfree(entry);
		--mm->num_unused;
	}
	spin_unlock(&mm->unused_lock);

	BUG_ON(mm->num_unused != 0);
}
EXPORT_SYMBOL(drm_mm_takedown);

void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
{
	struct drm_mm_node *entry;
	unsigned long total_used = 0, total_free = 0, total = 0;
	unsigned long hole_start, hole_end, hole_size;

	hole_start = drm_mm_hole_node_start(&mm->head_node);
	hole_end = drm_mm_hole_node_end(&mm->head_node);
	hole_size = hole_end - hole_start;
	if (hole_size)
		printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
			prefix, hole_start, hole_end,
			hole_size);
	total_free += hole_size;

	drm_mm_for_each_node(entry, mm) {
		printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
			prefix, entry->start, entry->start + entry->size,
			entry->size);
		total_used += entry->size;

		if (entry->hole_follows) {
			hole_start = drm_mm_hole_node_start(entry);
			hole_end = drm_mm_hole_node_end(entry);
			hole_size = hole_end - hole_start;
			printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
				prefix, hole_start, hole_end,
				hole_size);
			total_free += hole_size;
		}
	}
	total = total_free + total_used;

	printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
		total_used, total_free);
}
EXPORT_SYMBOL(drm_mm_debug_table);

#if defined(CONFIG_DEBUG_FS)
static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
{
	unsigned long hole_start, hole_end, hole_size;

	if (entry->hole_follows) {
		hole_start = drm_mm_hole_node_start(entry);
		hole_end = drm_mm_hole_node_end(entry);
		hole_size = hole_end - hole_start;
		seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
				hole_start, hole_end, hole_size);
		return hole_size;
	}

	return 0;
}

int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
{
	struct drm_mm_node *entry;
	unsigned long total_used = 0, total_free = 0, total = 0;

	total_free += drm_mm_dump_hole(m, &mm->head_node);

	drm_mm_for_each_node(entry, mm) {
		seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
				entry->start, entry->start + entry->size,
				entry->size);
		total_used += entry->size;
		total_free += drm_mm_dump_hole(m, entry);
	}
	total = total_free + total_used;

	seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
	return 0;
}
EXPORT_SYMBOL(drm_mm_dump_table);
#endif