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#include <linux/printk.h>
50#include <asm/bug.h>
51
52/**
53 * DOC: Overview
54 *
55 * drm_mm provides a simple range allocator. The drivers are free to use the
56 * resource allocator from the linux core if it suits them, the upside of drm_mm
57 * is that it's in the DRM core. Which means that it's easier to extend for
58 * some of the crazier special purpose needs of gpus.
59 *
60 * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node.
61 * Drivers are free to embed either of them into their own suitable
62 * datastructures. drm_mm itself will not do any allocations of its own, so if
63 * drivers choose not to embed nodes they need to still allocate them
64 * themselves.
65 *
66 * The range allocator also supports reservation of preallocated blocks. This is
67 * useful for taking over initial mode setting configurations from the firmware,
68 * where an object needs to be created which exactly matches the firmware's
69 * scanout target. As long as the range is still free it can be inserted anytime
70 * after the allocator is initialized, which helps with avoiding looped
71 * depencies in the driver load sequence.
72 *
73 * drm_mm maintains a stack of most recently freed holes, which of all
74 * simplistic datastructures seems to be a fairly decent approach to clustering
75 * allocations and avoiding too much fragmentation. This means free space
76 * searches are O(num_holes). Given that all the fancy features drm_mm supports
77 * something better would be fairly complex and since gfx thrashing is a fairly
78 * steep cliff not a real concern. Removing a node again is O(1).
79 *
80 * drm_mm supports a few features: Alignment and range restrictions can be
81 * supplied. Further more every &drm_mm_node has a color value (which is just an
82 * opaqua unsigned long) which in conjunction with a driver callback can be used
83 * to implement sophisticated placement restrictions. The i915 DRM driver uses
84 * this to implement guard pages between incompatible caching domains in the
85 * graphics TT.
86 *
87 * Two behaviors are supported for searching and allocating: bottom-up and top-down.
88 * The default is bottom-up. Top-down allocation can be used if the memory area
89 * has different restrictions, or just to reduce fragmentation.
90 *
91 * Finally iteration helpers to walk all nodes and all holes are provided as are
92 * some basic allocator dumpers for debugging.
93 */
94
95static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
96 unsigned long size,
97 unsigned alignment,
98 unsigned long color,
99 enum drm_mm_search_flags flags);
100static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
101 unsigned long size,
102 unsigned alignment,
103 unsigned long color,
104 unsigned long start,
105 unsigned long end,
106 enum drm_mm_search_flags flags);
107
108static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
109 struct drm_mm_node *node,
110 unsigned long size, unsigned alignment,
111 unsigned long color,
112 enum drm_mm_allocator_flags flags)
113{
114 struct drm_mm *mm = hole_node->mm;
115 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
116 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
117 unsigned long adj_start = hole_start;
118 unsigned long adj_end = hole_end;
119
120 BUG_ON(node->allocated);
121
122 if (mm->color_adjust)
123 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
124
125 if (flags & DRM_MM_CREATE_TOP)
126 adj_start = adj_end - size;
127
128 if (alignment) {
129 unsigned tmp = adj_start % alignment;
130 if (tmp) {
131 if (flags & DRM_MM_CREATE_TOP)
132 adj_start -= tmp;
133 else
134 adj_start += alignment - tmp;
135 }
136 }
137
138 BUG_ON(adj_start < hole_start);
139 BUG_ON(adj_end > hole_end);
140
141 if (adj_start == hole_start) {
142 hole_node->hole_follows = 0;
143 list_del(&hole_node->hole_stack);
144 }
145
146 node->start = adj_start;
147 node->size = size;
148 node->mm = mm;
149 node->color = color;
150 node->allocated = 1;
151
152 INIT_LIST_HEAD(&node->hole_stack);
153 list_add(&node->node_list, &hole_node->node_list);
154
155 BUG_ON(node->start + node->size > adj_end);
156
157 node->hole_follows = 0;
158 if (__drm_mm_hole_node_start(node) < hole_end) {
159 list_add(&node->hole_stack, &mm->hole_stack);
160 node->hole_follows = 1;
161 }
162}
163
164/**
165 * drm_mm_reserve_node - insert an pre-initialized node
166 * @mm: drm_mm allocator to insert @node into
167 * @node: drm_mm_node to insert
168 *
169 * This functions inserts an already set-up drm_mm_node into the allocator,
170 * meaning that start, size and color must be set by the caller. This is useful
171 * to initialize the allocator with preallocated objects which must be set-up
172 * before the range allocator can be set-up, e.g. when taking over a firmware
173 * framebuffer.
174 *
175 * Returns:
176 * 0 on success, -ENOSPC if there's no hole where @node is.
177 */
178int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
179{
180 struct drm_mm_node *hole;
181 unsigned long end = node->start + node->size;
182 unsigned long hole_start;
183 unsigned long hole_end;
184
185 BUG_ON(node == NULL);
186
187 /* Find the relevant hole to add our node to */
188 drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
189 if (hole_start > node->start || hole_end < end)
190 continue;
191
192 node->mm = mm;
193 node->allocated = 1;
194
195 INIT_LIST_HEAD(&node->hole_stack);
196 list_add(&node->node_list, &hole->node_list);
197
198 if (node->start == hole_start) {
199 hole->hole_follows = 0;
200 list_del_init(&hole->hole_stack);
201 }
202
203 node->hole_follows = 0;
204 if (end != hole_end) {
205 list_add(&node->hole_stack, &mm->hole_stack);
206 node->hole_follows = 1;
207 }
208
209 return 0;
210 }
211
212 return -ENOSPC;
213}
214EXPORT_SYMBOL(drm_mm_reserve_node);
215
216/**
217 * drm_mm_insert_node_generic - search for space and insert @node
218 * @mm: drm_mm to allocate from
219 * @node: preallocate node to insert
220 * @size: size of the allocation
221 * @alignment: alignment of the allocation
222 * @color: opaque tag value to use for this node
223 * @sflags: flags to fine-tune the allocation search
224 * @aflags: flags to fine-tune the allocation behavior
225 *
226 * The preallocated node must be cleared to 0.
227 *
228 * Returns:
229 * 0 on success, -ENOSPC if there's no suitable hole.
230 */
231int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
232 unsigned long size, unsigned alignment,
233 unsigned long color,
234 enum drm_mm_search_flags sflags,
235 enum drm_mm_allocator_flags aflags)
236{
237 struct drm_mm_node *hole_node;
238
239 hole_node = drm_mm_search_free_generic(mm, size, alignment,
240 color, sflags);
241 if (!hole_node)
242 return -ENOSPC;
243
244 drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags);
245 return 0;
246}
247EXPORT_SYMBOL(drm_mm_insert_node_generic);
248
249static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
250 struct drm_mm_node *node,
251 unsigned long size, unsigned alignment,
252 unsigned long color,
253 unsigned long start, unsigned long end,
254 enum drm_mm_allocator_flags flags)
255{
256 struct drm_mm *mm = hole_node->mm;
257 unsigned long hole_start = drm_mm_hole_node_start(hole_node);
258 unsigned long hole_end = drm_mm_hole_node_end(hole_node);
259 unsigned long adj_start = hole_start;
260 unsigned long adj_end = hole_end;
261
262 BUG_ON(!hole_node->hole_follows || node->allocated);
263
264 if (adj_start < start)
265 adj_start = start;
266 if (adj_end > end)
267 adj_end = end;
268
269 if (flags & DRM_MM_CREATE_TOP)
270 adj_start = adj_end - size;
271
272 if (mm->color_adjust)
273 mm->color_adjust(hole_node, color, &adj_start, &adj_end);
274
275 if (alignment) {
276 unsigned tmp = adj_start % alignment;
277 if (tmp) {
278 if (flags & DRM_MM_CREATE_TOP)
279 adj_start -= tmp;
280 else
281 adj_start += alignment - tmp;
282 }
283 }
284
285 if (adj_start == hole_start) {
286 hole_node->hole_follows = 0;
287 list_del(&hole_node->hole_stack);
288 }
289
290 node->start = adj_start;
291 node->size = size;
292 node->mm = mm;
293 node->color = color;
294 node->allocated = 1;
295
296 INIT_LIST_HEAD(&node->hole_stack);
297 list_add(&node->node_list, &hole_node->node_list);
298
299 BUG_ON(node->start < start);
300 BUG_ON(node->start < adj_start);
301 BUG_ON(node->start + node->size > adj_end);
302 BUG_ON(node->start + node->size > end);
303
304 node->hole_follows = 0;
305 if (__drm_mm_hole_node_start(node) < hole_end) {
306 list_add(&node->hole_stack, &mm->hole_stack);
307 node->hole_follows = 1;
308 }
309}
310
311/**
312 * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node
313 * @mm: drm_mm to allocate from
314 * @node: preallocate node to insert
315 * @size: size of the allocation
316 * @alignment: alignment of the allocation
317 * @color: opaque tag value to use for this node
318 * @start: start of the allowed range for this node
319 * @end: end of the allowed range for this node
320 * @sflags: flags to fine-tune the allocation search
321 * @aflags: flags to fine-tune the allocation behavior
322 *
323 * The preallocated node must be cleared to 0.
324 *
325 * Returns:
326 * 0 on success, -ENOSPC if there's no suitable hole.
327 */
328int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
329 unsigned long size, unsigned alignment,
330 unsigned long color,
331 unsigned long start, unsigned long end,
332 enum drm_mm_search_flags sflags,
333 enum drm_mm_allocator_flags aflags)
334{
335 struct drm_mm_node *hole_node;
336
337 hole_node = drm_mm_search_free_in_range_generic(mm,
338 size, alignment, color,
339 start, end, sflags);
340 if (!hole_node)
341 return -ENOSPC;
342
343 drm_mm_insert_helper_range(hole_node, node,
344 size, alignment, color,
345 start, end, aflags);
346 return 0;
347}
348EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
349
350/**
351 * drm_mm_remove_node - Remove a memory node from the allocator.
352 * @node: drm_mm_node to remove
353 *
354 * This just removes a node from its drm_mm allocator. The node does not need to
355 * be cleared again before it can be re-inserted into this or any other drm_mm
356 * allocator. It is a bug to call this function on a un-allocated node.
357 */
358void drm_mm_remove_node(struct drm_mm_node *node)
359{
360 struct drm_mm *mm = node->mm;
361 struct drm_mm_node *prev_node;
362
363 if (WARN_ON(!node->allocated))
364 return;
365
366 BUG_ON(node->scanned_block || node->scanned_prev_free
367 || node->scanned_next_free);
368
369 prev_node =
370 list_entry(node->node_list.prev, struct drm_mm_node, node_list);
371
372 if (node->hole_follows) {
373 BUG_ON(__drm_mm_hole_node_start(node) ==
374 __drm_mm_hole_node_end(node));
375 list_del(&node->hole_stack);
376 } else
377 BUG_ON(__drm_mm_hole_node_start(node) !=
378 __drm_mm_hole_node_end(node));
379
380
381 if (!prev_node->hole_follows) {
382 prev_node->hole_follows = 1;
383 list_add(&prev_node->hole_stack, &mm->hole_stack);
384 } else
385 list_move(&prev_node->hole_stack, &mm->hole_stack);
386
387 list_del(&node->node_list);
388 node->allocated = 0;
389}
390EXPORT_SYMBOL(drm_mm_remove_node);
391
392static int check_free_hole(unsigned long start, unsigned long end,
393 unsigned long size, unsigned alignment)
394{
395 if (end - start < size)
396 return 0;
397
398 if (alignment) {
399 unsigned tmp = start % alignment;
400 if (tmp)
401 start += alignment - tmp;
402 }
403
404 return end >= start + size;
405}
406
407static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
408 unsigned long size,
409 unsigned alignment,
410 unsigned long color,
411 enum drm_mm_search_flags flags)
412{
413 struct drm_mm_node *entry;
414 struct drm_mm_node *best;
415 unsigned long adj_start;
416 unsigned long adj_end;
417 unsigned long best_size;
418
419 BUG_ON(mm->scanned_blocks);
420
421 best = NULL;
422 best_size = ~0UL;
423
424 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
425 flags & DRM_MM_SEARCH_BELOW) {
426 unsigned long hole_size = adj_end - adj_start;
427
428 if (mm->color_adjust) {
429 mm->color_adjust(entry, color, &adj_start, &adj_end);
430 if (adj_end <= adj_start)
431 continue;
432 }
433
434 if (!check_free_hole(adj_start, adj_end, size, alignment))
435 continue;
436
437 if (!(flags & DRM_MM_SEARCH_BEST))
438 return entry;
439
440 if (hole_size < best_size) {
441 best = entry;
442 best_size = hole_size;
443 }
444 }
445
446 return best;
447}
448
449static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
450 unsigned long size,
451 unsigned alignment,
452 unsigned long color,
453 unsigned long start,
454 unsigned long end,
455 enum drm_mm_search_flags flags)
456{
457 struct drm_mm_node *entry;
458 struct drm_mm_node *best;
459 unsigned long adj_start;
460 unsigned long adj_end;
461 unsigned long best_size;
462
463 BUG_ON(mm->scanned_blocks);
464
465 best = NULL;
466 best_size = ~0UL;
467
468 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
469 flags & DRM_MM_SEARCH_BELOW) {
470 unsigned long hole_size = adj_end - adj_start;
471
472 if (adj_start < start)
473 adj_start = start;
474 if (adj_end > end)
475 adj_end = end;
476
477 if (mm->color_adjust) {
478 mm->color_adjust(entry, color, &adj_start, &adj_end);
479 if (adj_end <= adj_start)
480 continue;
481 }
482
483 if (!check_free_hole(adj_start, adj_end, size, alignment))
484 continue;
485
486 if (!(flags & DRM_MM_SEARCH_BEST))
487 return entry;
488
489 if (hole_size < best_size) {
490 best = entry;
491 best_size = hole_size;
492 }
493 }
494
495 return best;
496}
497
498/**
499 * drm_mm_replace_node - move an allocation from @old to @new
500 * @old: drm_mm_node to remove from the allocator
501 * @new: drm_mm_node which should inherit @old's allocation
502 *
503 * This is useful for when drivers embed the drm_mm_node structure and hence
504 * can't move allocations by reassigning pointers. It's a combination of remove
505 * and insert with the guarantee that the allocation start will match.
506 */
507void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
508{
509 list_replace(&old->node_list, &new->node_list);
510 list_replace(&old->hole_stack, &new->hole_stack);
511 new->hole_follows = old->hole_follows;
512 new->mm = old->mm;
513 new->start = old->start;
514 new->size = old->size;
515 new->color = old->color;
516
517 old->allocated = 0;
518 new->allocated = 1;
519}
520EXPORT_SYMBOL(drm_mm_replace_node);
521
522/**
523 * DOC: lru scan roaster
524 *
525 * Very often GPUs need to have continuous allocations for a given object. When
526 * evicting objects to make space for a new one it is therefore not most
527 * efficient when we simply start to select all objects from the tail of an LRU
528 * until there's a suitable hole: Especially for big objects or nodes that
529 * otherwise have special allocation constraints there's a good chance we evict
530 * lots of (smaller) objects unecessarily.
531 *
532 * The DRM range allocator supports this use-case through the scanning
533 * interfaces. First a scan operation needs to be initialized with
534 * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds
535 * objects to the roaster (probably by walking an LRU list, but this can be
536 * freely implemented) until a suitable hole is found or there's no further
537 * evitable object.
538 *
539 * The the driver must walk through all objects again in exactly the reverse
540 * order to restore the allocator state. Note that while the allocator is used
541 * in the scan mode no other operation is allowed.
542 *
543 * Finally the driver evicts all objects selected in the scan. Adding and
544 * removing an object is O(1), and since freeing a node is also O(1) the overall
545 * complexity is O(scanned_objects). So like the free stack which needs to be
546 * walked before a scan operation even begins this is linear in the number of
547 * objects. It doesn't seem to hurt badly.
548 */
549
550/**
551 * drm_mm_init_scan - initialize lru scanning
552 * @mm: drm_mm to scan
553 * @size: size of the allocation
554 * @alignment: alignment of the allocation
555 * @color: opaque tag value to use for the allocation
556 *
557 * This simply sets up the scanning routines with the parameters for the desired
558 * hole. Note that there's no need to specify allocation flags, since they only
559 * change the place a node is allocated from within a suitable hole.
560 *
561 * Warning:
562 * As long as the scan list is non-empty, no other operations than
563 * adding/removing nodes to/from the scan list are allowed.
564 */
565void drm_mm_init_scan(struct drm_mm *mm,
566 unsigned long size,
567 unsigned alignment,
568 unsigned long color)
569{
570 mm->scan_color = color;
571 mm->scan_alignment = alignment;
572 mm->scan_size = size;
573 mm->scanned_blocks = 0;
574 mm->scan_hit_start = 0;
575 mm->scan_hit_end = 0;
576 mm->scan_check_range = 0;
577 mm->prev_scanned_node = NULL;
578}
579EXPORT_SYMBOL(drm_mm_init_scan);
580
581/**
582 * drm_mm_init_scan - initialize range-restricted lru scanning
583 * @mm: drm_mm to scan
584 * @size: size of the allocation
585 * @alignment: alignment of the allocation
586 * @color: opaque tag value to use for the allocation
587 * @start: start of the allowed range for the allocation
588 * @end: end of the allowed range for the allocation
589 *
590 * This simply sets up the scanning routines with the parameters for the desired
591 * hole. Note that there's no need to specify allocation flags, since they only
592 * change the place a node is allocated from within a suitable hole.
593 *
594 * Warning:
595 * As long as the scan list is non-empty, no other operations than
596 * adding/removing nodes to/from the scan list are allowed.
597 */
598void drm_mm_init_scan_with_range(struct drm_mm *mm,
599 unsigned long size,
600 unsigned alignment,
601 unsigned long color,
602 unsigned long start,
603 unsigned long end)
604{
605 mm->scan_color = color;
606 mm->scan_alignment = alignment;
607 mm->scan_size = size;
608 mm->scanned_blocks = 0;
609 mm->scan_hit_start = 0;
610 mm->scan_hit_end = 0;
611 mm->scan_start = start;
612 mm->scan_end = end;
613 mm->scan_check_range = 1;
614 mm->prev_scanned_node = NULL;
615}
616EXPORT_SYMBOL(drm_mm_init_scan_with_range);
617
618/**
619 * drm_mm_scan_add_block - add a node to the scan list
620 * @node: drm_mm_node to add
621 *
622 * Add a node to the scan list that might be freed to make space for the desired
623 * hole.
624 *
625 * Returns:
626 * True if a hole has been found, false otherwise.
627 */
628bool drm_mm_scan_add_block(struct drm_mm_node *node)
629{
630 struct drm_mm *mm = node->mm;
631 struct drm_mm_node *prev_node;
632 unsigned long hole_start, hole_end;
633 unsigned long adj_start, adj_end;
634
635 mm->scanned_blocks++;
636
637 BUG_ON(node->scanned_block);
638 node->scanned_block = 1;
639
640 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
641 node_list);
642
643 node->scanned_preceeds_hole = prev_node->hole_follows;
644 prev_node->hole_follows = 1;
645 list_del(&node->node_list);
646 node->node_list.prev = &prev_node->node_list;
647 node->node_list.next = &mm->prev_scanned_node->node_list;
648 mm->prev_scanned_node = node;
649
650 adj_start = hole_start = drm_mm_hole_node_start(prev_node);
651 adj_end = hole_end = drm_mm_hole_node_end(prev_node);
652
653 if (mm->scan_check_range) {
654 if (adj_start < mm->scan_start)
655 adj_start = mm->scan_start;
656 if (adj_end > mm->scan_end)
657 adj_end = mm->scan_end;
658 }
659
660 if (mm->color_adjust)
661 mm->color_adjust(prev_node, mm->scan_color,
662 &adj_start, &adj_end);
663
664 if (check_free_hole(adj_start, adj_end,
665 mm->scan_size, mm->scan_alignment)) {
666 mm->scan_hit_start = hole_start;
667 mm->scan_hit_end = hole_end;
668 return true;
669 }
670
671 return false;
672}
673EXPORT_SYMBOL(drm_mm_scan_add_block);
674
675/**
676 * drm_mm_scan_remove_block - remove a node from the scan list
677 * @node: drm_mm_node to remove
678 *
679 * Nodes _must_ be removed in the exact same order from the scan list as they
680 * have been added, otherwise the internal state of the memory manager will be
681 * corrupted.
682 *
683 * When the scan list is empty, the selected memory nodes can be freed. An
684 * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then
685 * return the just freed block (because its at the top of the free_stack list).
686 *
687 * Returns:
688 * True if this block should be evicted, false otherwise. Will always
689 * return false when no hole has been found.
690 */
691bool drm_mm_scan_remove_block(struct drm_mm_node *node)
692{
693 struct drm_mm *mm = node->mm;
694 struct drm_mm_node *prev_node;
695
696 mm->scanned_blocks--;
697
698 BUG_ON(!node->scanned_block);
699 node->scanned_block = 0;
700
701 prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
702 node_list);
703
704 prev_node->hole_follows = node->scanned_preceeds_hole;
705 list_add(&node->node_list, &prev_node->node_list);
706
707 return (drm_mm_hole_node_end(node) > mm->scan_hit_start &&
708 node->start < mm->scan_hit_end);
709}
710EXPORT_SYMBOL(drm_mm_scan_remove_block);
711
712/**
713 * drm_mm_clean - checks whether an allocator is clean
714 * @mm: drm_mm allocator to check
715 *
716 * Returns:
717 * True if the allocator is completely free, false if there's still a node
718 * allocated in it.
719 */
720bool drm_mm_clean(struct drm_mm * mm)
721{
722 struct list_head *head = &mm->head_node.node_list;
723
724 return (head->next->next == head);
725}
726EXPORT_SYMBOL(drm_mm_clean);
727
728/**
729 * drm_mm_init - initialize a drm-mm allocator
730 * @mm: the drm_mm structure to initialize
731 * @start: start of the range managed by @mm
732 * @size: end of the range managed by @mm
733 *
734 * Note that @mm must be cleared to 0 before calling this function.
735 */
736void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
737{
738 INIT_LIST_HEAD(&mm->hole_stack);
739 mm->scanned_blocks = 0;
740
741 /* Clever trick to avoid a special case in the free hole tracking. */
742 INIT_LIST_HEAD(&mm->head_node.node_list);
743 INIT_LIST_HEAD(&mm->head_node.hole_stack);
744 mm->head_node.hole_follows = 1;
745 mm->head_node.scanned_block = 0;
746 mm->head_node.scanned_prev_free = 0;
747 mm->head_node.scanned_next_free = 0;
748 mm->head_node.mm = mm;
749 mm->head_node.start = start + size;
750 mm->head_node.size = start - mm->head_node.start;
751 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
752
753 mm->color_adjust = NULL;
754}
755EXPORT_SYMBOL(drm_mm_init);
756
757/**
758 * drm_mm_takedown - clean up a drm_mm allocator
759 * @mm: drm_mm allocator to clean up
760 *
761 * Note that it is a bug to call this function on an allocator which is not
762 * clean.
763 */
764void drm_mm_takedown(struct drm_mm * mm)
765{
766 WARN(!list_empty(&mm->head_node.node_list),
767 "Memory manager not clean during takedown.\n");
768}
769EXPORT_SYMBOL(drm_mm_takedown);
770
771static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry,
772 const char *prefix)
773{
774 unsigned long hole_start, hole_end, hole_size;
775
776 if (entry->hole_follows) {
777 hole_start = drm_mm_hole_node_start(entry);
778 hole_end = drm_mm_hole_node_end(entry);
779 hole_size = hole_end - hole_start;
780 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
781 prefix, hole_start, hole_end,
782 hole_size);
783 return hole_size;
784 }
785
786 return 0;
787}
788
789/**
790 * drm_mm_debug_table - dump allocator state to dmesg
791 * @mm: drm_mm allocator to dump
792 * @prefix: prefix to use for dumping to dmesg
793 */
794void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
795{
796 struct drm_mm_node *entry;
797 unsigned long total_used = 0, total_free = 0, total = 0;
798
799 total_free += drm_mm_debug_hole(&mm->head_node, prefix);
800
801 drm_mm_for_each_node(entry, mm) {
802 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
803 prefix, entry->start, entry->start + entry->size,
804 entry->size);
805 total_used += entry->size;
806 total_free += drm_mm_debug_hole(entry, prefix);
807 }
808 total = total_free + total_used;
809
810 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
811 total_used, total_free);
812}
813EXPORT_SYMBOL(drm_mm_debug_table);
814
815#if defined(CONFIG_DEBUG_FS)
816static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
817{
818 unsigned long hole_start, hole_end, hole_size;
819
820 if (entry->hole_follows) {
821 hole_start = drm_mm_hole_node_start(entry);
822 hole_end = drm_mm_hole_node_end(entry);
823 hole_size = hole_end - hole_start;
824 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
825 hole_start, hole_end, hole_size);
826 return hole_size;
827 }
828
829 return 0;
830}
831
832/**
833 * drm_mm_dump_table - dump allocator state to a seq_file
834 * @m: seq_file to dump to
835 * @mm: drm_mm allocator to dump
836 */
837int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
838{
839 struct drm_mm_node *entry;
840 unsigned long total_used = 0, total_free = 0, total = 0;
841
842 total_free += drm_mm_dump_hole(m, &mm->head_node);
843
844 drm_mm_for_each_node(entry, mm) {
845 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
846 entry->start, entry->start + entry->size,
847 entry->size);
848 total_used += entry->size;
849 total_free += drm_mm_dump_hole(m, entry);
850 }
851 total = total_free + total_used;
852
853 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
854 return 0;
855}
856EXPORT_SYMBOL(drm_mm_dump_table);
857#endif
858