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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 <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/interval_tree_generic.h> | |
50 | ||
51 | /** | |
52 | * DOC: Overview | |
53 | * | |
54 | * drm_mm provides a simple range allocator. The drivers are free to use the | |
55 | * resource allocator from the linux core if it suits them, the upside of drm_mm | |
56 | * is that it's in the DRM core. Which means that it's easier to extend for | |
57 | * some of the crazier special purpose needs of gpus. | |
58 | * | |
59 | * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node. | |
60 | * Drivers are free to embed either of them into their own suitable | |
61 | * datastructures. drm_mm itself will not do any allocations of its own, so if | |
62 | * drivers choose not to embed nodes they need to still allocate them | |
63 | * themselves. | |
64 | * | |
65 | * The range allocator also supports reservation of preallocated blocks. This is | |
66 | * useful for taking over initial mode setting configurations from the firmware, | |
67 | * where an object needs to be created which exactly matches the firmware's | |
68 | * scanout target. As long as the range is still free it can be inserted anytime | |
69 | * after the allocator is initialized, which helps with avoiding looped | |
70 | * depencies in the driver load sequence. | |
71 | * | |
72 | * drm_mm maintains a stack of most recently freed holes, which of all | |
73 | * simplistic datastructures seems to be a fairly decent approach to clustering | |
74 | * allocations and avoiding too much fragmentation. This means free space | |
75 | * searches are O(num_holes). Given that all the fancy features drm_mm supports | |
76 | * something better would be fairly complex and since gfx thrashing is a fairly | |
77 | * steep cliff not a real concern. Removing a node again is O(1). | |
78 | * | |
79 | * drm_mm supports a few features: Alignment and range restrictions can be | |
80 | * supplied. Further more every &drm_mm_node has a color value (which is just an | |
81 | * opaqua unsigned long) which in conjunction with a driver callback can be used | |
82 | * to implement sophisticated placement restrictions. The i915 DRM driver uses | |
83 | * this to implement guard pages between incompatible caching domains in the | |
84 | * graphics TT. | |
85 | * | |
86 | * Two behaviors are supported for searching and allocating: bottom-up and top-down. | |
87 | * The default is bottom-up. Top-down allocation can be used if the memory area | |
88 | * has different restrictions, or just to reduce fragmentation. | |
89 | * | |
90 | * Finally iteration helpers to walk all nodes and all holes are provided as are | |
91 | * some basic allocator dumpers for debugging. | |
92 | */ | |
93 | ||
94 | static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, | |
95 | u64 size, | |
96 | unsigned alignment, | |
97 | unsigned long color, | |
98 | enum drm_mm_search_flags flags); | |
99 | static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, | |
100 | u64 size, | |
101 | unsigned alignment, | |
102 | unsigned long color, | |
103 | u64 start, | |
104 | u64 end, | |
105 | enum drm_mm_search_flags flags); | |
106 | ||
107 | #ifdef CONFIG_DRM_DEBUG_MM | |
108 | #define STACKDEPTH 32 | |
109 | #define BUFSZ 4096 | |
110 | ||
111 | static noinline void save_stack(struct drm_mm_node *node) | |
112 | { | |
113 | unsigned long entries[STACKDEPTH]; | |
114 | struct stack_trace trace = { | |
115 | .entries = entries, | |
116 | .max_entries = STACKDEPTH, | |
117 | .skip = 1 | |
118 | }; | |
119 | ||
120 | save_stack_trace(&trace); | |
121 | if (trace.nr_entries != 0 && | |
122 | trace.entries[trace.nr_entries-1] == ULONG_MAX) | |
123 | trace.nr_entries--; | |
124 | ||
125 | /* May be called under spinlock, so avoid sleeping */ | |
126 | node->stack = depot_save_stack(&trace, GFP_NOWAIT); | |
127 | } | |
128 | ||
129 | static void show_leaks(struct drm_mm *mm) | |
130 | { | |
131 | struct drm_mm_node *node; | |
132 | unsigned long entries[STACKDEPTH]; | |
133 | char *buf; | |
134 | ||
135 | buf = kmalloc(BUFSZ, GFP_KERNEL); | |
136 | if (!buf) | |
137 | return; | |
138 | ||
139 | list_for_each_entry(node, &mm->head_node.node_list, node_list) { | |
140 | struct stack_trace trace = { | |
141 | .entries = entries, | |
142 | .max_entries = STACKDEPTH | |
143 | }; | |
144 | ||
145 | if (!node->stack) { | |
146 | DRM_ERROR("node [%08llx + %08llx]: unknown owner\n", | |
147 | node->start, node->size); | |
148 | continue; | |
149 | } | |
150 | ||
151 | depot_fetch_stack(node->stack, &trace); | |
152 | snprint_stack_trace(buf, BUFSZ, &trace, 0); | |
153 | DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s", | |
154 | node->start, node->size, buf); | |
155 | } | |
156 | ||
157 | kfree(buf); | |
158 | } | |
159 | ||
160 | #undef STACKDEPTH | |
161 | #undef BUFSZ | |
162 | #else | |
163 | static void save_stack(struct drm_mm_node *node) { } | |
164 | static void show_leaks(struct drm_mm *mm) { } | |
165 | #endif | |
166 | ||
167 | #define START(node) ((node)->start) | |
168 | #define LAST(node) ((node)->start + (node)->size - 1) | |
169 | ||
170 | INTERVAL_TREE_DEFINE(struct drm_mm_node, rb, | |
171 | u64, __subtree_last, | |
172 | START, LAST, static inline, drm_mm_interval_tree) | |
173 | ||
174 | struct drm_mm_node * | |
175 | drm_mm_interval_first(struct drm_mm *mm, u64 start, u64 last) | |
176 | { | |
177 | return drm_mm_interval_tree_iter_first(&mm->interval_tree, | |
178 | start, last); | |
179 | } | |
180 | EXPORT_SYMBOL(drm_mm_interval_first); | |
181 | ||
182 | struct drm_mm_node * | |
183 | drm_mm_interval_next(struct drm_mm_node *node, u64 start, u64 last) | |
184 | { | |
185 | return drm_mm_interval_tree_iter_next(node, start, last); | |
186 | } | |
187 | EXPORT_SYMBOL(drm_mm_interval_next); | |
188 | ||
189 | static void drm_mm_interval_tree_add_node(struct drm_mm_node *hole_node, | |
190 | struct drm_mm_node *node) | |
191 | { | |
192 | struct drm_mm *mm = hole_node->mm; | |
193 | struct rb_node **link, *rb; | |
194 | struct drm_mm_node *parent; | |
195 | ||
196 | node->__subtree_last = LAST(node); | |
197 | ||
198 | if (hole_node->allocated) { | |
199 | rb = &hole_node->rb; | |
200 | while (rb) { | |
201 | parent = rb_entry(rb, struct drm_mm_node, rb); | |
202 | if (parent->__subtree_last >= node->__subtree_last) | |
203 | break; | |
204 | ||
205 | parent->__subtree_last = node->__subtree_last; | |
206 | rb = rb_parent(rb); | |
207 | } | |
208 | ||
209 | rb = &hole_node->rb; | |
210 | link = &hole_node->rb.rb_right; | |
211 | } else { | |
212 | rb = NULL; | |
213 | link = &mm->interval_tree.rb_node; | |
214 | } | |
215 | ||
216 | while (*link) { | |
217 | rb = *link; | |
218 | parent = rb_entry(rb, struct drm_mm_node, rb); | |
219 | if (parent->__subtree_last < node->__subtree_last) | |
220 | parent->__subtree_last = node->__subtree_last; | |
221 | if (node->start < parent->start) | |
222 | link = &parent->rb.rb_left; | |
223 | else | |
224 | link = &parent->rb.rb_right; | |
225 | } | |
226 | ||
227 | rb_link_node(&node->rb, rb, link); | |
228 | rb_insert_augmented(&node->rb, | |
229 | &mm->interval_tree, | |
230 | &drm_mm_interval_tree_augment); | |
231 | } | |
232 | ||
233 | static void drm_mm_insert_helper(struct drm_mm_node *hole_node, | |
234 | struct drm_mm_node *node, | |
235 | u64 size, unsigned alignment, | |
236 | unsigned long color, | |
237 | enum drm_mm_allocator_flags flags) | |
238 | { | |
239 | struct drm_mm *mm = hole_node->mm; | |
240 | u64 hole_start = drm_mm_hole_node_start(hole_node); | |
241 | u64 hole_end = drm_mm_hole_node_end(hole_node); | |
242 | u64 adj_start = hole_start; | |
243 | u64 adj_end = hole_end; | |
244 | ||
245 | BUG_ON(node->allocated); | |
246 | ||
247 | if (mm->color_adjust) | |
248 | mm->color_adjust(hole_node, color, &adj_start, &adj_end); | |
249 | ||
250 | if (flags & DRM_MM_CREATE_TOP) | |
251 | adj_start = adj_end - size; | |
252 | ||
253 | if (alignment) { | |
254 | u64 tmp = adj_start; | |
255 | unsigned rem; | |
256 | ||
257 | rem = do_div(tmp, alignment); | |
258 | if (rem) { | |
259 | if (flags & DRM_MM_CREATE_TOP) | |
260 | adj_start -= rem; | |
261 | else | |
262 | adj_start += alignment - rem; | |
263 | } | |
264 | } | |
265 | ||
266 | BUG_ON(adj_start < hole_start); | |
267 | BUG_ON(adj_end > hole_end); | |
268 | ||
269 | if (adj_start == hole_start) { | |
270 | hole_node->hole_follows = 0; | |
271 | list_del(&hole_node->hole_stack); | |
272 | } | |
273 | ||
274 | node->start = adj_start; | |
275 | node->size = size; | |
276 | node->mm = mm; | |
277 | node->color = color; | |
278 | node->allocated = 1; | |
279 | ||
280 | list_add(&node->node_list, &hole_node->node_list); | |
281 | ||
282 | drm_mm_interval_tree_add_node(hole_node, node); | |
283 | ||
284 | BUG_ON(node->start + node->size > adj_end); | |
285 | ||
286 | node->hole_follows = 0; | |
287 | if (__drm_mm_hole_node_start(node) < hole_end) { | |
288 | list_add(&node->hole_stack, &mm->hole_stack); | |
289 | node->hole_follows = 1; | |
290 | } | |
291 | ||
292 | save_stack(node); | |
293 | } | |
294 | ||
295 | /** | |
296 | * drm_mm_reserve_node - insert an pre-initialized node | |
297 | * @mm: drm_mm allocator to insert @node into | |
298 | * @node: drm_mm_node to insert | |
299 | * | |
300 | * This functions inserts an already set-up drm_mm_node into the allocator, | |
301 | * meaning that start, size and color must be set by the caller. This is useful | |
302 | * to initialize the allocator with preallocated objects which must be set-up | |
303 | * before the range allocator can be set-up, e.g. when taking over a firmware | |
304 | * framebuffer. | |
305 | * | |
306 | * Returns: | |
307 | * 0 on success, -ENOSPC if there's no hole where @node is. | |
308 | */ | |
309 | int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) | |
310 | { | |
311 | u64 end = node->start + node->size; | |
312 | struct drm_mm_node *hole; | |
313 | u64 hole_start, hole_end; | |
314 | ||
315 | if (WARN_ON(node->size == 0)) | |
316 | return -EINVAL; | |
317 | ||
318 | end = node->start + node->size; | |
319 | ||
320 | /* Find the relevant hole to add our node to */ | |
321 | hole = drm_mm_interval_tree_iter_first(&mm->interval_tree, | |
322 | node->start, ~(u64)0); | |
323 | if (hole) { | |
324 | if (hole->start < end) | |
325 | return -ENOSPC; | |
326 | } else { | |
327 | hole = list_entry(&mm->head_node.node_list, | |
328 | typeof(*hole), node_list); | |
329 | } | |
330 | ||
331 | hole = list_last_entry(&hole->node_list, typeof(*hole), node_list); | |
332 | if (!hole->hole_follows) | |
333 | return -ENOSPC; | |
334 | ||
335 | hole_start = __drm_mm_hole_node_start(hole); | |
336 | hole_end = __drm_mm_hole_node_end(hole); | |
337 | if (hole_start > node->start || hole_end < end) | |
338 | return -ENOSPC; | |
339 | ||
340 | node->mm = mm; | |
341 | node->allocated = 1; | |
342 | ||
343 | list_add(&node->node_list, &hole->node_list); | |
344 | ||
345 | drm_mm_interval_tree_add_node(hole, node); | |
346 | ||
347 | if (node->start == hole_start) { | |
348 | hole->hole_follows = 0; | |
349 | list_del(&hole->hole_stack); | |
350 | } | |
351 | ||
352 | node->hole_follows = 0; | |
353 | if (end != hole_end) { | |
354 | list_add(&node->hole_stack, &mm->hole_stack); | |
355 | node->hole_follows = 1; | |
356 | } | |
357 | ||
358 | save_stack(node); | |
359 | ||
360 | return 0; | |
361 | } | |
362 | EXPORT_SYMBOL(drm_mm_reserve_node); | |
363 | ||
364 | /** | |
365 | * drm_mm_insert_node_generic - search for space and insert @node | |
366 | * @mm: drm_mm to allocate from | |
367 | * @node: preallocate node to insert | |
368 | * @size: size of the allocation | |
369 | * @alignment: alignment of the allocation | |
370 | * @color: opaque tag value to use for this node | |
371 | * @sflags: flags to fine-tune the allocation search | |
372 | * @aflags: flags to fine-tune the allocation behavior | |
373 | * | |
374 | * The preallocated node must be cleared to 0. | |
375 | * | |
376 | * Returns: | |
377 | * 0 on success, -ENOSPC if there's no suitable hole. | |
378 | */ | |
379 | int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node, | |
380 | u64 size, unsigned alignment, | |
381 | unsigned long color, | |
382 | enum drm_mm_search_flags sflags, | |
383 | enum drm_mm_allocator_flags aflags) | |
384 | { | |
385 | struct drm_mm_node *hole_node; | |
386 | ||
387 | if (WARN_ON(size == 0)) | |
388 | return -EINVAL; | |
389 | ||
390 | hole_node = drm_mm_search_free_generic(mm, size, alignment, | |
391 | color, sflags); | |
392 | if (!hole_node) | |
393 | return -ENOSPC; | |
394 | ||
395 | drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags); | |
396 | return 0; | |
397 | } | |
398 | EXPORT_SYMBOL(drm_mm_insert_node_generic); | |
399 | ||
400 | static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node, | |
401 | struct drm_mm_node *node, | |
402 | u64 size, unsigned alignment, | |
403 | unsigned long color, | |
404 | u64 start, u64 end, | |
405 | enum drm_mm_allocator_flags flags) | |
406 | { | |
407 | struct drm_mm *mm = hole_node->mm; | |
408 | u64 hole_start = drm_mm_hole_node_start(hole_node); | |
409 | u64 hole_end = drm_mm_hole_node_end(hole_node); | |
410 | u64 adj_start = hole_start; | |
411 | u64 adj_end = hole_end; | |
412 | ||
413 | BUG_ON(!hole_node->hole_follows || node->allocated); | |
414 | ||
415 | if (adj_start < start) | |
416 | adj_start = start; | |
417 | if (adj_end > end) | |
418 | adj_end = end; | |
419 | ||
420 | if (mm->color_adjust) | |
421 | mm->color_adjust(hole_node, color, &adj_start, &adj_end); | |
422 | ||
423 | if (flags & DRM_MM_CREATE_TOP) | |
424 | adj_start = adj_end - size; | |
425 | ||
426 | if (alignment) { | |
427 | u64 tmp = adj_start; | |
428 | unsigned rem; | |
429 | ||
430 | rem = do_div(tmp, alignment); | |
431 | if (rem) { | |
432 | if (flags & DRM_MM_CREATE_TOP) | |
433 | adj_start -= rem; | |
434 | else | |
435 | adj_start += alignment - rem; | |
436 | } | |
437 | } | |
438 | ||
439 | if (adj_start == hole_start) { | |
440 | hole_node->hole_follows = 0; | |
441 | list_del(&hole_node->hole_stack); | |
442 | } | |
443 | ||
444 | node->start = adj_start; | |
445 | node->size = size; | |
446 | node->mm = mm; | |
447 | node->color = color; | |
448 | node->allocated = 1; | |
449 | ||
450 | list_add(&node->node_list, &hole_node->node_list); | |
451 | ||
452 | drm_mm_interval_tree_add_node(hole_node, node); | |
453 | ||
454 | BUG_ON(node->start < start); | |
455 | BUG_ON(node->start < adj_start); | |
456 | BUG_ON(node->start + node->size > adj_end); | |
457 | BUG_ON(node->start + node->size > end); | |
458 | ||
459 | node->hole_follows = 0; | |
460 | if (__drm_mm_hole_node_start(node) < hole_end) { | |
461 | list_add(&node->hole_stack, &mm->hole_stack); | |
462 | node->hole_follows = 1; | |
463 | } | |
464 | ||
465 | save_stack(node); | |
466 | } | |
467 | ||
468 | /** | |
469 | * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node | |
470 | * @mm: drm_mm to allocate from | |
471 | * @node: preallocate node to insert | |
472 | * @size: size of the allocation | |
473 | * @alignment: alignment of the allocation | |
474 | * @color: opaque tag value to use for this node | |
475 | * @start: start of the allowed range for this node | |
476 | * @end: end of the allowed range for this node | |
477 | * @sflags: flags to fine-tune the allocation search | |
478 | * @aflags: flags to fine-tune the allocation behavior | |
479 | * | |
480 | * The preallocated node must be cleared to 0. | |
481 | * | |
482 | * Returns: | |
483 | * 0 on success, -ENOSPC if there's no suitable hole. | |
484 | */ | |
485 | int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node, | |
486 | u64 size, unsigned alignment, | |
487 | unsigned long color, | |
488 | u64 start, u64 end, | |
489 | enum drm_mm_search_flags sflags, | |
490 | enum drm_mm_allocator_flags aflags) | |
491 | { | |
492 | struct drm_mm_node *hole_node; | |
493 | ||
494 | if (WARN_ON(size == 0)) | |
495 | return -EINVAL; | |
496 | ||
497 | hole_node = drm_mm_search_free_in_range_generic(mm, | |
498 | size, alignment, color, | |
499 | start, end, sflags); | |
500 | if (!hole_node) | |
501 | return -ENOSPC; | |
502 | ||
503 | drm_mm_insert_helper_range(hole_node, node, | |
504 | size, alignment, color, | |
505 | start, end, aflags); | |
506 | return 0; | |
507 | } | |
508 | EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic); | |
509 | ||
510 | /** | |
511 | * drm_mm_remove_node - Remove a memory node from the allocator. | |
512 | * @node: drm_mm_node to remove | |
513 | * | |
514 | * This just removes a node from its drm_mm allocator. The node does not need to | |
515 | * be cleared again before it can be re-inserted into this or any other drm_mm | |
516 | * allocator. It is a bug to call this function on a un-allocated node. | |
517 | */ | |
518 | void drm_mm_remove_node(struct drm_mm_node *node) | |
519 | { | |
520 | struct drm_mm *mm = node->mm; | |
521 | struct drm_mm_node *prev_node; | |
522 | ||
523 | if (WARN_ON(!node->allocated)) | |
524 | return; | |
525 | ||
526 | BUG_ON(node->scanned_block || node->scanned_prev_free | |
527 | || node->scanned_next_free); | |
528 | ||
529 | prev_node = | |
530 | list_entry(node->node_list.prev, struct drm_mm_node, node_list); | |
531 | ||
532 | if (node->hole_follows) { | |
533 | BUG_ON(__drm_mm_hole_node_start(node) == | |
534 | __drm_mm_hole_node_end(node)); | |
535 | list_del(&node->hole_stack); | |
536 | } else | |
537 | BUG_ON(__drm_mm_hole_node_start(node) != | |
538 | __drm_mm_hole_node_end(node)); | |
539 | ||
540 | ||
541 | if (!prev_node->hole_follows) { | |
542 | prev_node->hole_follows = 1; | |
543 | list_add(&prev_node->hole_stack, &mm->hole_stack); | |
544 | } else | |
545 | list_move(&prev_node->hole_stack, &mm->hole_stack); | |
546 | ||
547 | drm_mm_interval_tree_remove(node, &mm->interval_tree); | |
548 | list_del(&node->node_list); | |
549 | node->allocated = 0; | |
550 | } | |
551 | EXPORT_SYMBOL(drm_mm_remove_node); | |
552 | ||
553 | static int check_free_hole(u64 start, u64 end, u64 size, unsigned alignment) | |
554 | { | |
555 | if (end - start < size) | |
556 | return 0; | |
557 | ||
558 | if (alignment) { | |
559 | u64 tmp = start; | |
560 | unsigned rem; | |
561 | ||
562 | rem = do_div(tmp, alignment); | |
563 | if (rem) | |
564 | start += alignment - rem; | |
565 | } | |
566 | ||
567 | return end >= start + size; | |
568 | } | |
569 | ||
570 | static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, | |
571 | u64 size, | |
572 | unsigned alignment, | |
573 | unsigned long color, | |
574 | enum drm_mm_search_flags flags) | |
575 | { | |
576 | struct drm_mm_node *entry; | |
577 | struct drm_mm_node *best; | |
578 | u64 adj_start; | |
579 | u64 adj_end; | |
580 | u64 best_size; | |
581 | ||
582 | BUG_ON(mm->scanned_blocks); | |
583 | ||
584 | best = NULL; | |
585 | best_size = ~0UL; | |
586 | ||
587 | __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, | |
588 | flags & DRM_MM_SEARCH_BELOW) { | |
589 | u64 hole_size = adj_end - adj_start; | |
590 | ||
591 | if (mm->color_adjust) { | |
592 | mm->color_adjust(entry, color, &adj_start, &adj_end); | |
593 | if (adj_end <= adj_start) | |
594 | continue; | |
595 | } | |
596 | ||
597 | if (!check_free_hole(adj_start, adj_end, size, alignment)) | |
598 | continue; | |
599 | ||
600 | if (!(flags & DRM_MM_SEARCH_BEST)) | |
601 | return entry; | |
602 | ||
603 | if (hole_size < best_size) { | |
604 | best = entry; | |
605 | best_size = hole_size; | |
606 | } | |
607 | } | |
608 | ||
609 | return best; | |
610 | } | |
611 | ||
612 | static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, | |
613 | u64 size, | |
614 | unsigned alignment, | |
615 | unsigned long color, | |
616 | u64 start, | |
617 | u64 end, | |
618 | enum drm_mm_search_flags flags) | |
619 | { | |
620 | struct drm_mm_node *entry; | |
621 | struct drm_mm_node *best; | |
622 | u64 adj_start; | |
623 | u64 adj_end; | |
624 | u64 best_size; | |
625 | ||
626 | BUG_ON(mm->scanned_blocks); | |
627 | ||
628 | best = NULL; | |
629 | best_size = ~0UL; | |
630 | ||
631 | __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, | |
632 | flags & DRM_MM_SEARCH_BELOW) { | |
633 | u64 hole_size = adj_end - adj_start; | |
634 | ||
635 | if (adj_start < start) | |
636 | adj_start = start; | |
637 | if (adj_end > end) | |
638 | adj_end = end; | |
639 | ||
640 | if (mm->color_adjust) { | |
641 | mm->color_adjust(entry, color, &adj_start, &adj_end); | |
642 | if (adj_end <= adj_start) | |
643 | continue; | |
644 | } | |
645 | ||
646 | if (!check_free_hole(adj_start, adj_end, size, alignment)) | |
647 | continue; | |
648 | ||
649 | if (!(flags & DRM_MM_SEARCH_BEST)) | |
650 | return entry; | |
651 | ||
652 | if (hole_size < best_size) { | |
653 | best = entry; | |
654 | best_size = hole_size; | |
655 | } | |
656 | } | |
657 | ||
658 | return best; | |
659 | } | |
660 | ||
661 | /** | |
662 | * drm_mm_replace_node - move an allocation from @old to @new | |
663 | * @old: drm_mm_node to remove from the allocator | |
664 | * @new: drm_mm_node which should inherit @old's allocation | |
665 | * | |
666 | * This is useful for when drivers embed the drm_mm_node structure and hence | |
667 | * can't move allocations by reassigning pointers. It's a combination of remove | |
668 | * and insert with the guarantee that the allocation start will match. | |
669 | */ | |
670 | void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new) | |
671 | { | |
672 | list_replace(&old->node_list, &new->node_list); | |
673 | list_replace(&old->hole_stack, &new->hole_stack); | |
674 | rb_replace_node(&old->rb, &new->rb, &old->mm->interval_tree); | |
675 | new->hole_follows = old->hole_follows; | |
676 | new->mm = old->mm; | |
677 | new->start = old->start; | |
678 | new->size = old->size; | |
679 | new->color = old->color; | |
680 | new->__subtree_last = old->__subtree_last; | |
681 | ||
682 | old->allocated = 0; | |
683 | new->allocated = 1; | |
684 | } | |
685 | EXPORT_SYMBOL(drm_mm_replace_node); | |
686 | ||
687 | /** | |
688 | * DOC: lru scan roaster | |
689 | * | |
690 | * Very often GPUs need to have continuous allocations for a given object. When | |
691 | * evicting objects to make space for a new one it is therefore not most | |
692 | * efficient when we simply start to select all objects from the tail of an LRU | |
693 | * until there's a suitable hole: Especially for big objects or nodes that | |
694 | * otherwise have special allocation constraints there's a good chance we evict | |
695 | * lots of (smaller) objects unecessarily. | |
696 | * | |
697 | * The DRM range allocator supports this use-case through the scanning | |
698 | * interfaces. First a scan operation needs to be initialized with | |
699 | * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds | |
700 | * objects to the roaster (probably by walking an LRU list, but this can be | |
701 | * freely implemented) until a suitable hole is found or there's no further | |
702 | * evitable object. | |
703 | * | |
704 | * The the driver must walk through all objects again in exactly the reverse | |
705 | * order to restore the allocator state. Note that while the allocator is used | |
706 | * in the scan mode no other operation is allowed. | |
707 | * | |
708 | * Finally the driver evicts all objects selected in the scan. Adding and | |
709 | * removing an object is O(1), and since freeing a node is also O(1) the overall | |
710 | * complexity is O(scanned_objects). So like the free stack which needs to be | |
711 | * walked before a scan operation even begins this is linear in the number of | |
712 | * objects. It doesn't seem to hurt badly. | |
713 | */ | |
714 | ||
715 | /** | |
716 | * drm_mm_init_scan - initialize lru scanning | |
717 | * @mm: drm_mm to scan | |
718 | * @size: size of the allocation | |
719 | * @alignment: alignment of the allocation | |
720 | * @color: opaque tag value to use for the allocation | |
721 | * | |
722 | * This simply sets up the scanning routines with the parameters for the desired | |
723 | * hole. Note that there's no need to specify allocation flags, since they only | |
724 | * change the place a node is allocated from within a suitable hole. | |
725 | * | |
726 | * Warning: | |
727 | * As long as the scan list is non-empty, no other operations than | |
728 | * adding/removing nodes to/from the scan list are allowed. | |
729 | */ | |
730 | void drm_mm_init_scan(struct drm_mm *mm, | |
731 | u64 size, | |
732 | unsigned alignment, | |
733 | unsigned long color) | |
734 | { | |
735 | mm->scan_color = color; | |
736 | mm->scan_alignment = alignment; | |
737 | mm->scan_size = size; | |
738 | mm->scanned_blocks = 0; | |
739 | mm->scan_hit_start = 0; | |
740 | mm->scan_hit_end = 0; | |
741 | mm->scan_check_range = 0; | |
742 | mm->prev_scanned_node = NULL; | |
743 | } | |
744 | EXPORT_SYMBOL(drm_mm_init_scan); | |
745 | ||
746 | /** | |
747 | * drm_mm_init_scan - initialize range-restricted lru scanning | |
748 | * @mm: drm_mm to scan | |
749 | * @size: size of the allocation | |
750 | * @alignment: alignment of the allocation | |
751 | * @color: opaque tag value to use for the allocation | |
752 | * @start: start of the allowed range for the allocation | |
753 | * @end: end of the allowed range for the allocation | |
754 | * | |
755 | * This simply sets up the scanning routines with the parameters for the desired | |
756 | * hole. Note that there's no need to specify allocation flags, since they only | |
757 | * change the place a node is allocated from within a suitable hole. | |
758 | * | |
759 | * Warning: | |
760 | * As long as the scan list is non-empty, no other operations than | |
761 | * adding/removing nodes to/from the scan list are allowed. | |
762 | */ | |
763 | void drm_mm_init_scan_with_range(struct drm_mm *mm, | |
764 | u64 size, | |
765 | unsigned alignment, | |
766 | unsigned long color, | |
767 | u64 start, | |
768 | u64 end) | |
769 | { | |
770 | mm->scan_color = color; | |
771 | mm->scan_alignment = alignment; | |
772 | mm->scan_size = size; | |
773 | mm->scanned_blocks = 0; | |
774 | mm->scan_hit_start = 0; | |
775 | mm->scan_hit_end = 0; | |
776 | mm->scan_start = start; | |
777 | mm->scan_end = end; | |
778 | mm->scan_check_range = 1; | |
779 | mm->prev_scanned_node = NULL; | |
780 | } | |
781 | EXPORT_SYMBOL(drm_mm_init_scan_with_range); | |
782 | ||
783 | /** | |
784 | * drm_mm_scan_add_block - add a node to the scan list | |
785 | * @node: drm_mm_node to add | |
786 | * | |
787 | * Add a node to the scan list that might be freed to make space for the desired | |
788 | * hole. | |
789 | * | |
790 | * Returns: | |
791 | * True if a hole has been found, false otherwise. | |
792 | */ | |
793 | bool drm_mm_scan_add_block(struct drm_mm_node *node) | |
794 | { | |
795 | struct drm_mm *mm = node->mm; | |
796 | struct drm_mm_node *prev_node; | |
797 | u64 hole_start, hole_end; | |
798 | u64 adj_start, adj_end; | |
799 | ||
800 | mm->scanned_blocks++; | |
801 | ||
802 | BUG_ON(node->scanned_block); | |
803 | node->scanned_block = 1; | |
804 | ||
805 | prev_node = list_entry(node->node_list.prev, struct drm_mm_node, | |
806 | node_list); | |
807 | ||
808 | node->scanned_preceeds_hole = prev_node->hole_follows; | |
809 | prev_node->hole_follows = 1; | |
810 | list_del(&node->node_list); | |
811 | node->node_list.prev = &prev_node->node_list; | |
812 | node->node_list.next = &mm->prev_scanned_node->node_list; | |
813 | mm->prev_scanned_node = node; | |
814 | ||
815 | adj_start = hole_start = drm_mm_hole_node_start(prev_node); | |
816 | adj_end = hole_end = drm_mm_hole_node_end(prev_node); | |
817 | ||
818 | if (mm->scan_check_range) { | |
819 | if (adj_start < mm->scan_start) | |
820 | adj_start = mm->scan_start; | |
821 | if (adj_end > mm->scan_end) | |
822 | adj_end = mm->scan_end; | |
823 | } | |
824 | ||
825 | if (mm->color_adjust) | |
826 | mm->color_adjust(prev_node, mm->scan_color, | |
827 | &adj_start, &adj_end); | |
828 | ||
829 | if (check_free_hole(adj_start, adj_end, | |
830 | mm->scan_size, mm->scan_alignment)) { | |
831 | mm->scan_hit_start = hole_start; | |
832 | mm->scan_hit_end = hole_end; | |
833 | return true; | |
834 | } | |
835 | ||
836 | return false; | |
837 | } | |
838 | EXPORT_SYMBOL(drm_mm_scan_add_block); | |
839 | ||
840 | /** | |
841 | * drm_mm_scan_remove_block - remove a node from the scan list | |
842 | * @node: drm_mm_node to remove | |
843 | * | |
844 | * Nodes _must_ be removed in the exact same order from the scan list as they | |
845 | * have been added, otherwise the internal state of the memory manager will be | |
846 | * corrupted. | |
847 | * | |
848 | * When the scan list is empty, the selected memory nodes can be freed. An | |
849 | * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then | |
850 | * return the just freed block (because its at the top of the free_stack list). | |
851 | * | |
852 | * Returns: | |
853 | * True if this block should be evicted, false otherwise. Will always | |
854 | * return false when no hole has been found. | |
855 | */ | |
856 | bool drm_mm_scan_remove_block(struct drm_mm_node *node) | |
857 | { | |
858 | struct drm_mm *mm = node->mm; | |
859 | struct drm_mm_node *prev_node; | |
860 | ||
861 | mm->scanned_blocks--; | |
862 | ||
863 | BUG_ON(!node->scanned_block); | |
864 | node->scanned_block = 0; | |
865 | ||
866 | prev_node = list_entry(node->node_list.prev, struct drm_mm_node, | |
867 | node_list); | |
868 | ||
869 | prev_node->hole_follows = node->scanned_preceeds_hole; | |
870 | list_add(&node->node_list, &prev_node->node_list); | |
871 | ||
872 | return (drm_mm_hole_node_end(node) > mm->scan_hit_start && | |
873 | node->start < mm->scan_hit_end); | |
874 | } | |
875 | EXPORT_SYMBOL(drm_mm_scan_remove_block); | |
876 | ||
877 | /** | |
878 | * drm_mm_clean - checks whether an allocator is clean | |
879 | * @mm: drm_mm allocator to check | |
880 | * | |
881 | * Returns: | |
882 | * True if the allocator is completely free, false if there's still a node | |
883 | * allocated in it. | |
884 | */ | |
885 | bool drm_mm_clean(struct drm_mm * mm) | |
886 | { | |
887 | struct list_head *head = &mm->head_node.node_list; | |
888 | ||
889 | return (head->next->next == head); | |
890 | } | |
891 | EXPORT_SYMBOL(drm_mm_clean); | |
892 | ||
893 | /** | |
894 | * drm_mm_init - initialize a drm-mm allocator | |
895 | * @mm: the drm_mm structure to initialize | |
896 | * @start: start of the range managed by @mm | |
897 | * @size: end of the range managed by @mm | |
898 | * | |
899 | * Note that @mm must be cleared to 0 before calling this function. | |
900 | */ | |
901 | void drm_mm_init(struct drm_mm * mm, u64 start, u64 size) | |
902 | { | |
903 | INIT_LIST_HEAD(&mm->hole_stack); | |
904 | mm->scanned_blocks = 0; | |
905 | ||
906 | /* Clever trick to avoid a special case in the free hole tracking. */ | |
907 | INIT_LIST_HEAD(&mm->head_node.node_list); | |
908 | mm->head_node.hole_follows = 1; | |
909 | mm->head_node.scanned_block = 0; | |
910 | mm->head_node.scanned_prev_free = 0; | |
911 | mm->head_node.scanned_next_free = 0; | |
912 | mm->head_node.mm = mm; | |
913 | mm->head_node.start = start + size; | |
914 | mm->head_node.size = start - mm->head_node.start; | |
915 | list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack); | |
916 | ||
917 | mm->interval_tree = RB_ROOT; | |
918 | ||
919 | mm->color_adjust = NULL; | |
920 | } | |
921 | EXPORT_SYMBOL(drm_mm_init); | |
922 | ||
923 | /** | |
924 | * drm_mm_takedown - clean up a drm_mm allocator | |
925 | * @mm: drm_mm allocator to clean up | |
926 | * | |
927 | * Note that it is a bug to call this function on an allocator which is not | |
928 | * clean. | |
929 | */ | |
930 | void drm_mm_takedown(struct drm_mm *mm) | |
931 | { | |
932 | if (WARN(!list_empty(&mm->head_node.node_list), | |
933 | "Memory manager not clean during takedown.\n")) | |
934 | show_leaks(mm); | |
935 | ||
936 | } | |
937 | EXPORT_SYMBOL(drm_mm_takedown); | |
938 | ||
939 | static u64 drm_mm_debug_hole(struct drm_mm_node *entry, | |
940 | const char *prefix) | |
941 | { | |
942 | u64 hole_start, hole_end, hole_size; | |
943 | ||
944 | if (entry->hole_follows) { | |
945 | hole_start = drm_mm_hole_node_start(entry); | |
946 | hole_end = drm_mm_hole_node_end(entry); | |
947 | hole_size = hole_end - hole_start; | |
948 | pr_debug("%s %#llx-%#llx: %llu: free\n", prefix, hole_start, | |
949 | hole_end, hole_size); | |
950 | return hole_size; | |
951 | } | |
952 | ||
953 | return 0; | |
954 | } | |
955 | ||
956 | /** | |
957 | * drm_mm_debug_table - dump allocator state to dmesg | |
958 | * @mm: drm_mm allocator to dump | |
959 | * @prefix: prefix to use for dumping to dmesg | |
960 | */ | |
961 | void drm_mm_debug_table(struct drm_mm *mm, const char *prefix) | |
962 | { | |
963 | struct drm_mm_node *entry; | |
964 | u64 total_used = 0, total_free = 0, total = 0; | |
965 | ||
966 | total_free += drm_mm_debug_hole(&mm->head_node, prefix); | |
967 | ||
968 | drm_mm_for_each_node(entry, mm) { | |
969 | pr_debug("%s %#llx-%#llx: %llu: used\n", prefix, entry->start, | |
970 | entry->start + entry->size, entry->size); | |
971 | total_used += entry->size; | |
972 | total_free += drm_mm_debug_hole(entry, prefix); | |
973 | } | |
974 | total = total_free + total_used; | |
975 | ||
976 | pr_debug("%s total: %llu, used %llu free %llu\n", prefix, total, | |
977 | total_used, total_free); | |
978 | } | |
979 | EXPORT_SYMBOL(drm_mm_debug_table); | |
980 | ||
981 | #if defined(CONFIG_DEBUG_FS) | |
982 | static u64 drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry) | |
983 | { | |
984 | u64 hole_start, hole_end, hole_size; | |
985 | ||
986 | if (entry->hole_follows) { | |
987 | hole_start = drm_mm_hole_node_start(entry); | |
988 | hole_end = drm_mm_hole_node_end(entry); | |
989 | hole_size = hole_end - hole_start; | |
990 | seq_printf(m, "%#018llx-%#018llx: %llu: free\n", hole_start, | |
991 | hole_end, hole_size); | |
992 | return hole_size; | |
993 | } | |
994 | ||
995 | return 0; | |
996 | } | |
997 | ||
998 | /** | |
999 | * drm_mm_dump_table - dump allocator state to a seq_file | |
1000 | * @m: seq_file to dump to | |
1001 | * @mm: drm_mm allocator to dump | |
1002 | */ | |
1003 | int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm) | |
1004 | { | |
1005 | struct drm_mm_node *entry; | |
1006 | u64 total_used = 0, total_free = 0, total = 0; | |
1007 | ||
1008 | total_free += drm_mm_dump_hole(m, &mm->head_node); | |
1009 | ||
1010 | drm_mm_for_each_node(entry, mm) { | |
1011 | seq_printf(m, "%#018llx-%#018llx: %llu: used\n", entry->start, | |
1012 | entry->start + entry->size, entry->size); | |
1013 | total_used += entry->size; | |
1014 | total_free += drm_mm_dump_hole(m, entry); | |
1015 | } | |
1016 | total = total_free + total_used; | |
1017 | ||
1018 | seq_printf(m, "total: %llu, used %llu free %llu\n", total, | |
1019 | total_used, total_free); | |
1020 | return 0; | |
1021 | } | |
1022 | EXPORT_SYMBOL(drm_mm_dump_table); | |
1023 | #endif |