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3a1bd924 TH |
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: | |
96de0e25 | 41 | * Thomas Hellström <thomas-at-tungstengraphics-dot-com> |
3a1bd924 TH |
42 | */ |
43 | ||
760285e7 DH |
44 | #include <drm/drmP.h> |
45 | #include <drm/drm_mm.h> | |
1d58420b | 46 | #include <linux/slab.h> |
fa8a1238 | 47 | #include <linux/seq_file.h> |
2d1a8a48 | 48 | #include <linux/export.h> |
1d58420b | 49 | |
93110be6 DV |
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 | * Finally iteration helpers to walk all nodes and all holes are provided as are | |
86 | * some basic allocator dumpers for debugging. | |
87 | */ | |
88 | ||
c700c67b DH |
89 | static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, |
90 | unsigned long size, | |
91 | unsigned alignment, | |
92 | unsigned long color, | |
93 | enum drm_mm_search_flags flags); | |
94 | static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, | |
95 | unsigned long size, | |
96 | unsigned alignment, | |
97 | unsigned long color, | |
98 | unsigned long start, | |
99 | unsigned long end, | |
100 | enum drm_mm_search_flags flags); | |
1d58420b | 101 | |
9fc935de DV |
102 | static void drm_mm_insert_helper(struct drm_mm_node *hole_node, |
103 | struct drm_mm_node *node, | |
6b9d89b4 CW |
104 | unsigned long size, unsigned alignment, |
105 | unsigned long color) | |
3a1bd924 | 106 | { |
ea7b1dd4 | 107 | struct drm_mm *mm = hole_node->mm; |
ea7b1dd4 DV |
108 | unsigned long hole_start = drm_mm_hole_node_start(hole_node); |
109 | unsigned long hole_end = drm_mm_hole_node_end(hole_node); | |
6b9d89b4 CW |
110 | unsigned long adj_start = hole_start; |
111 | unsigned long adj_end = hole_end; | |
ea7b1dd4 | 112 | |
9e8944ab | 113 | BUG_ON(node->allocated); |
b0b7af18 | 114 | |
6b9d89b4 CW |
115 | if (mm->color_adjust) |
116 | mm->color_adjust(hole_node, color, &adj_start, &adj_end); | |
1d58420b | 117 | |
6b9d89b4 CW |
118 | if (alignment) { |
119 | unsigned tmp = adj_start % alignment; | |
120 | if (tmp) | |
121 | adj_start += alignment - tmp; | |
122 | } | |
123 | ||
124 | if (adj_start == hole_start) { | |
ea7b1dd4 | 125 | hole_node->hole_follows = 0; |
6b9d89b4 CW |
126 | list_del(&hole_node->hole_stack); |
127 | } | |
ea7b1dd4 | 128 | |
6b9d89b4 | 129 | node->start = adj_start; |
ea7b1dd4 DV |
130 | node->size = size; |
131 | node->mm = mm; | |
6b9d89b4 | 132 | node->color = color; |
b0b7af18 | 133 | node->allocated = 1; |
3a1bd924 | 134 | |
ea7b1dd4 DV |
135 | INIT_LIST_HEAD(&node->hole_stack); |
136 | list_add(&node->node_list, &hole_node->node_list); | |
137 | ||
6b9d89b4 | 138 | BUG_ON(node->start + node->size > adj_end); |
ea7b1dd4 | 139 | |
6b9d89b4 | 140 | node->hole_follows = 0; |
9e8944ab | 141 | if (__drm_mm_hole_node_start(node) < hole_end) { |
ea7b1dd4 DV |
142 | list_add(&node->hole_stack, &mm->hole_stack); |
143 | node->hole_follows = 1; | |
1d58420b | 144 | } |
9fc935de DV |
145 | } |
146 | ||
e18c0412 DV |
147 | /** |
148 | * drm_mm_reserve_node - insert an pre-initialized node | |
149 | * @mm: drm_mm allocator to insert @node into | |
150 | * @node: drm_mm_node to insert | |
151 | * | |
152 | * This functions inserts an already set-up drm_mm_node into the allocator, | |
153 | * meaning that start, size and color must be set by the caller. This is useful | |
154 | * to initialize the allocator with preallocated objects which must be set-up | |
155 | * before the range allocator can be set-up, e.g. when taking over a firmware | |
156 | * framebuffer. | |
157 | * | |
158 | * Returns: | |
159 | * 0 on success, -ENOSPC if there's no hole where @node is. | |
160 | */ | |
338710e7 | 161 | int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) |
5973c7ee | 162 | { |
b3a070cc | 163 | struct drm_mm_node *hole; |
338710e7 | 164 | unsigned long end = node->start + node->size; |
9e8944ab CW |
165 | unsigned long hole_start; |
166 | unsigned long hole_end; | |
5973c7ee | 167 | |
338710e7 BW |
168 | BUG_ON(node == NULL); |
169 | ||
170 | /* Find the relevant hole to add our node to */ | |
9e8944ab | 171 | drm_mm_for_each_hole(hole, mm, hole_start, hole_end) { |
338710e7 | 172 | if (hole_start > node->start || hole_end < end) |
5973c7ee CW |
173 | continue; |
174 | ||
5973c7ee CW |
175 | node->mm = mm; |
176 | node->allocated = 1; | |
177 | ||
178 | INIT_LIST_HEAD(&node->hole_stack); | |
179 | list_add(&node->node_list, &hole->node_list); | |
180 | ||
338710e7 | 181 | if (node->start == hole_start) { |
5973c7ee CW |
182 | hole->hole_follows = 0; |
183 | list_del_init(&hole->hole_stack); | |
184 | } | |
185 | ||
186 | node->hole_follows = 0; | |
187 | if (end != hole_end) { | |
188 | list_add(&node->hole_stack, &mm->hole_stack); | |
189 | node->hole_follows = 1; | |
190 | } | |
191 | ||
b3a070cc | 192 | return 0; |
5973c7ee CW |
193 | } |
194 | ||
338710e7 BW |
195 | WARN(1, "no hole found for node 0x%lx + 0x%lx\n", |
196 | node->start, node->size); | |
b3a070cc | 197 | return -ENOSPC; |
5973c7ee | 198 | } |
338710e7 | 199 | EXPORT_SYMBOL(drm_mm_reserve_node); |
5973c7ee | 200 | |
b0b7af18 | 201 | /** |
e18c0412 DV |
202 | * drm_mm_insert_node_generic - search for space and insert @node |
203 | * @mm: drm_mm to allocate from | |
204 | * @node: preallocate node to insert | |
205 | * @size: size of the allocation | |
206 | * @alignment: alignment of the allocation | |
207 | * @color: opaque tag value to use for this node | |
208 | * @flags: flags to fine-tune the allocation | |
209 | * | |
210 | * The preallocated node must be cleared to 0. | |
211 | * | |
212 | * Returns: | |
213 | * 0 on success, -ENOSPC if there's no suitable hole. | |
b0b7af18 | 214 | */ |
b8103450 CW |
215 | int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node, |
216 | unsigned long size, unsigned alignment, | |
31e5d7c6 DH |
217 | unsigned long color, |
218 | enum drm_mm_search_flags flags) | |
b0b7af18 DV |
219 | { |
220 | struct drm_mm_node *hole_node; | |
221 | ||
b8103450 | 222 | hole_node = drm_mm_search_free_generic(mm, size, alignment, |
31e5d7c6 | 223 | color, flags); |
b0b7af18 DV |
224 | if (!hole_node) |
225 | return -ENOSPC; | |
226 | ||
b8103450 | 227 | drm_mm_insert_helper(hole_node, node, size, alignment, color); |
b0b7af18 DV |
228 | return 0; |
229 | } | |
b8103450 CW |
230 | EXPORT_SYMBOL(drm_mm_insert_node_generic); |
231 | ||
9fc935de DV |
232 | static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node, |
233 | struct drm_mm_node *node, | |
234 | unsigned long size, unsigned alignment, | |
6b9d89b4 | 235 | unsigned long color, |
9fc935de | 236 | unsigned long start, unsigned long end) |
a2e68e92 | 237 | { |
ea7b1dd4 | 238 | struct drm_mm *mm = hole_node->mm; |
ea7b1dd4 DV |
239 | unsigned long hole_start = drm_mm_hole_node_start(hole_node); |
240 | unsigned long hole_end = drm_mm_hole_node_end(hole_node); | |
6b9d89b4 CW |
241 | unsigned long adj_start = hole_start; |
242 | unsigned long adj_end = hole_end; | |
a2e68e92 | 243 | |
b0b7af18 DV |
244 | BUG_ON(!hole_node->hole_follows || node->allocated); |
245 | ||
6b9d89b4 CW |
246 | if (adj_start < start) |
247 | adj_start = start; | |
901593f2 CW |
248 | if (adj_end > end) |
249 | adj_end = end; | |
250 | ||
251 | if (mm->color_adjust) | |
252 | mm->color_adjust(hole_node, color, &adj_start, &adj_end); | |
6b9d89b4 CW |
253 | |
254 | if (alignment) { | |
255 | unsigned tmp = adj_start % alignment; | |
256 | if (tmp) | |
257 | adj_start += alignment - tmp; | |
258 | } | |
ea7b1dd4 | 259 | |
6b9d89b4 | 260 | if (adj_start == hole_start) { |
ea7b1dd4 | 261 | hole_node->hole_follows = 0; |
6b9d89b4 | 262 | list_del(&hole_node->hole_stack); |
a2e68e92 JG |
263 | } |
264 | ||
6b9d89b4 | 265 | node->start = adj_start; |
ea7b1dd4 DV |
266 | node->size = size; |
267 | node->mm = mm; | |
6b9d89b4 | 268 | node->color = color; |
b0b7af18 | 269 | node->allocated = 1; |
ea7b1dd4 DV |
270 | |
271 | INIT_LIST_HEAD(&node->hole_stack); | |
272 | list_add(&node->node_list, &hole_node->node_list); | |
273 | ||
6b9d89b4 | 274 | BUG_ON(node->start + node->size > adj_end); |
ea7b1dd4 DV |
275 | BUG_ON(node->start + node->size > end); |
276 | ||
6b9d89b4 | 277 | node->hole_follows = 0; |
9e8944ab | 278 | if (__drm_mm_hole_node_start(node) < hole_end) { |
ea7b1dd4 DV |
279 | list_add(&node->hole_stack, &mm->hole_stack); |
280 | node->hole_follows = 1; | |
a2e68e92 | 281 | } |
9fc935de DV |
282 | } |
283 | ||
b0b7af18 | 284 | /** |
e18c0412 DV |
285 | * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node |
286 | * @mm: drm_mm to allocate from | |
287 | * @node: preallocate node to insert | |
288 | * @size: size of the allocation | |
289 | * @alignment: alignment of the allocation | |
290 | * @color: opaque tag value to use for this node | |
291 | * @start: start of the allowed range for this node | |
292 | * @end: end of the allowed range for this node | |
293 | * @flags: flags to fine-tune the allocation | |
294 | * | |
295 | * The preallocated node must be cleared to 0. | |
296 | * | |
297 | * Returns: | |
298 | * 0 on success, -ENOSPC if there's no suitable hole. | |
3a1bd924 | 299 | */ |
b8103450 CW |
300 | int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node, |
301 | unsigned long size, unsigned alignment, unsigned long color, | |
31e5d7c6 DH |
302 | unsigned long start, unsigned long end, |
303 | enum drm_mm_search_flags flags) | |
3a1bd924 | 304 | { |
b0b7af18 DV |
305 | struct drm_mm_node *hole_node; |
306 | ||
b8103450 CW |
307 | hole_node = drm_mm_search_free_in_range_generic(mm, |
308 | size, alignment, color, | |
31e5d7c6 | 309 | start, end, flags); |
b0b7af18 DV |
310 | if (!hole_node) |
311 | return -ENOSPC; | |
312 | ||
b8103450 CW |
313 | drm_mm_insert_helper_range(hole_node, node, |
314 | size, alignment, color, | |
b0b7af18 | 315 | start, end); |
b0b7af18 DV |
316 | return 0; |
317 | } | |
b8103450 CW |
318 | EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic); |
319 | ||
b0b7af18 | 320 | /** |
e18c0412 DV |
321 | * drm_mm_remove_node - Remove a memory node from the allocator. |
322 | * @node: drm_mm_node to remove | |
323 | * | |
324 | * This just removes a node from its drm_mm allocator. The node does not need to | |
325 | * be cleared again before it can be re-inserted into this or any other drm_mm | |
326 | * allocator. It is a bug to call this function on a un-allocated node. | |
b0b7af18 DV |
327 | */ |
328 | void drm_mm_remove_node(struct drm_mm_node *node) | |
329 | { | |
ea7b1dd4 DV |
330 | struct drm_mm *mm = node->mm; |
331 | struct drm_mm_node *prev_node; | |
3a1bd924 | 332 | |
3ef80a81 BW |
333 | if (WARN_ON(!node->allocated)) |
334 | return; | |
335 | ||
ea7b1dd4 DV |
336 | BUG_ON(node->scanned_block || node->scanned_prev_free |
337 | || node->scanned_next_free); | |
3a1bd924 | 338 | |
ea7b1dd4 DV |
339 | prev_node = |
340 | list_entry(node->node_list.prev, struct drm_mm_node, node_list); | |
709ea971 | 341 | |
ea7b1dd4 | 342 | if (node->hole_follows) { |
9e8944ab CW |
343 | BUG_ON(__drm_mm_hole_node_start(node) == |
344 | __drm_mm_hole_node_end(node)); | |
ea7b1dd4 DV |
345 | list_del(&node->hole_stack); |
346 | } else | |
9e8944ab CW |
347 | BUG_ON(__drm_mm_hole_node_start(node) != |
348 | __drm_mm_hole_node_end(node)); | |
349 | ||
249d6048 | 350 | |
ea7b1dd4 DV |
351 | if (!prev_node->hole_follows) { |
352 | prev_node->hole_follows = 1; | |
353 | list_add(&prev_node->hole_stack, &mm->hole_stack); | |
354 | } else | |
355 | list_move(&prev_node->hole_stack, &mm->hole_stack); | |
356 | ||
357 | list_del(&node->node_list); | |
b0b7af18 DV |
358 | node->allocated = 0; |
359 | } | |
360 | EXPORT_SYMBOL(drm_mm_remove_node); | |
361 | ||
75214733 DV |
362 | static int check_free_hole(unsigned long start, unsigned long end, |
363 | unsigned long size, unsigned alignment) | |
7a6b2896 | 364 | { |
75214733 | 365 | if (end - start < size) |
7a6b2896 DV |
366 | return 0; |
367 | ||
368 | if (alignment) { | |
75214733 | 369 | unsigned tmp = start % alignment; |
7a6b2896 | 370 | if (tmp) |
6b9d89b4 | 371 | start += alignment - tmp; |
7a6b2896 DV |
372 | } |
373 | ||
6b9d89b4 | 374 | return end >= start + size; |
7a6b2896 DV |
375 | } |
376 | ||
c700c67b DH |
377 | static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, |
378 | unsigned long size, | |
379 | unsigned alignment, | |
380 | unsigned long color, | |
381 | enum drm_mm_search_flags flags) | |
3a1bd924 | 382 | { |
55910517 DA |
383 | struct drm_mm_node *entry; |
384 | struct drm_mm_node *best; | |
9e8944ab CW |
385 | unsigned long adj_start; |
386 | unsigned long adj_end; | |
3a1bd924 TH |
387 | unsigned long best_size; |
388 | ||
709ea971 DV |
389 | BUG_ON(mm->scanned_blocks); |
390 | ||
3a1bd924 TH |
391 | best = NULL; |
392 | best_size = ~0UL; | |
393 | ||
9e8944ab | 394 | drm_mm_for_each_hole(entry, mm, adj_start, adj_end) { |
6b9d89b4 CW |
395 | if (mm->color_adjust) { |
396 | mm->color_adjust(entry, color, &adj_start, &adj_end); | |
397 | if (adj_end <= adj_start) | |
398 | continue; | |
399 | } | |
400 | ||
6b9d89b4 | 401 | if (!check_free_hole(adj_start, adj_end, size, alignment)) |
1d58420b TH |
402 | continue; |
403 | ||
31e5d7c6 | 404 | if (!(flags & DRM_MM_SEARCH_BEST)) |
7a6b2896 | 405 | return entry; |
1d58420b | 406 | |
7a6b2896 DV |
407 | if (entry->size < best_size) { |
408 | best = entry; | |
409 | best_size = entry->size; | |
3a1bd924 TH |
410 | } |
411 | } | |
412 | ||
413 | return best; | |
414 | } | |
6b9d89b4 | 415 | |
c700c67b | 416 | static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, |
6b9d89b4 CW |
417 | unsigned long size, |
418 | unsigned alignment, | |
419 | unsigned long color, | |
420 | unsigned long start, | |
421 | unsigned long end, | |
31e5d7c6 | 422 | enum drm_mm_search_flags flags) |
a2e68e92 | 423 | { |
a2e68e92 JG |
424 | struct drm_mm_node *entry; |
425 | struct drm_mm_node *best; | |
9e8944ab CW |
426 | unsigned long adj_start; |
427 | unsigned long adj_end; | |
a2e68e92 | 428 | unsigned long best_size; |
a2e68e92 | 429 | |
709ea971 DV |
430 | BUG_ON(mm->scanned_blocks); |
431 | ||
a2e68e92 JG |
432 | best = NULL; |
433 | best_size = ~0UL; | |
434 | ||
9e8944ab CW |
435 | drm_mm_for_each_hole(entry, mm, adj_start, adj_end) { |
436 | if (adj_start < start) | |
437 | adj_start = start; | |
438 | if (adj_end > end) | |
439 | adj_end = end; | |
6b9d89b4 CW |
440 | |
441 | if (mm->color_adjust) { | |
442 | mm->color_adjust(entry, color, &adj_start, &adj_end); | |
443 | if (adj_end <= adj_start) | |
444 | continue; | |
445 | } | |
446 | ||
75214733 | 447 | if (!check_free_hole(adj_start, adj_end, size, alignment)) |
a2e68e92 JG |
448 | continue; |
449 | ||
31e5d7c6 | 450 | if (!(flags & DRM_MM_SEARCH_BEST)) |
7a6b2896 | 451 | return entry; |
a2e68e92 | 452 | |
7a6b2896 DV |
453 | if (entry->size < best_size) { |
454 | best = entry; | |
455 | best_size = entry->size; | |
a2e68e92 JG |
456 | } |
457 | } | |
458 | ||
459 | return best; | |
460 | } | |
a2e68e92 | 461 | |
b0b7af18 | 462 | /** |
e18c0412 DV |
463 | * drm_mm_replace_node - move an allocation from @old to @new |
464 | * @old: drm_mm_node to remove from the allocator | |
465 | * @new: drm_mm_node which should inherit @old's allocation | |
466 | * | |
467 | * This is useful for when drivers embed the drm_mm_node structure and hence | |
468 | * can't move allocations by reassigning pointers. It's a combination of remove | |
469 | * and insert with the guarantee that the allocation start will match. | |
b0b7af18 DV |
470 | */ |
471 | void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new) | |
472 | { | |
473 | list_replace(&old->node_list, &new->node_list); | |
2bbd4492 | 474 | list_replace(&old->hole_stack, &new->hole_stack); |
b0b7af18 DV |
475 | new->hole_follows = old->hole_follows; |
476 | new->mm = old->mm; | |
477 | new->start = old->start; | |
478 | new->size = old->size; | |
6b9d89b4 | 479 | new->color = old->color; |
b0b7af18 DV |
480 | |
481 | old->allocated = 0; | |
482 | new->allocated = 1; | |
483 | } | |
484 | EXPORT_SYMBOL(drm_mm_replace_node); | |
485 | ||
93110be6 DV |
486 | /** |
487 | * DOC: lru scan roaster | |
488 | * | |
489 | * Very often GPUs need to have continuous allocations for a given object. When | |
490 | * evicting objects to make space for a new one it is therefore not most | |
491 | * efficient when we simply start to select all objects from the tail of an LRU | |
492 | * until there's a suitable hole: Especially for big objects or nodes that | |
493 | * otherwise have special allocation constraints there's a good chance we evict | |
494 | * lots of (smaller) objects unecessarily. | |
495 | * | |
496 | * The DRM range allocator supports this use-case through the scanning | |
497 | * interfaces. First a scan operation needs to be initialized with | |
498 | * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds | |
499 | * objects to the roaster (probably by walking an LRU list, but this can be | |
500 | * freely implemented) until a suitable hole is found or there's no further | |
501 | * evitable object. | |
502 | * | |
503 | * The the driver must walk through all objects again in exactly the reverse | |
504 | * order to restore the allocator state. Note that while the allocator is used | |
505 | * in the scan mode no other operation is allowed. | |
506 | * | |
507 | * Finally the driver evicts all objects selected in the scan. Adding and | |
508 | * removing an object is O(1), and since freeing a node is also O(1) the overall | |
509 | * complexity is O(scanned_objects). So like the free stack which needs to be | |
510 | * walked before a scan operation even begins this is linear in the number of | |
511 | * objects. It doesn't seem to hurt badly. | |
512 | */ | |
513 | ||
709ea971 | 514 | /** |
e18c0412 DV |
515 | * drm_mm_init_scan - initialize lru scanning |
516 | * @mm: drm_mm to scan | |
517 | * @size: size of the allocation | |
518 | * @alignment: alignment of the allocation | |
519 | * @color: opaque tag value to use for the allocation | |
709ea971 DV |
520 | * |
521 | * This simply sets up the scanning routines with the parameters for the desired | |
e18c0412 DV |
522 | * hole. Note that there's no need to specify allocation flags, since they only |
523 | * change the place a node is allocated from within a suitable hole. | |
709ea971 | 524 | * |
e18c0412 DV |
525 | * Warning: |
526 | * As long as the scan list is non-empty, no other operations than | |
709ea971 DV |
527 | * adding/removing nodes to/from the scan list are allowed. |
528 | */ | |
6b9d89b4 CW |
529 | void drm_mm_init_scan(struct drm_mm *mm, |
530 | unsigned long size, | |
531 | unsigned alignment, | |
532 | unsigned long color) | |
709ea971 | 533 | { |
6b9d89b4 | 534 | mm->scan_color = color; |
709ea971 DV |
535 | mm->scan_alignment = alignment; |
536 | mm->scan_size = size; | |
537 | mm->scanned_blocks = 0; | |
538 | mm->scan_hit_start = 0; | |
901593f2 | 539 | mm->scan_hit_end = 0; |
d935cc61 | 540 | mm->scan_check_range = 0; |
ae0cec28 | 541 | mm->prev_scanned_node = NULL; |
709ea971 DV |
542 | } |
543 | EXPORT_SYMBOL(drm_mm_init_scan); | |
544 | ||
d935cc61 | 545 | /** |
e18c0412 DV |
546 | * drm_mm_init_scan - initialize range-restricted lru scanning |
547 | * @mm: drm_mm to scan | |
548 | * @size: size of the allocation | |
549 | * @alignment: alignment of the allocation | |
550 | * @color: opaque tag value to use for the allocation | |
551 | * @start: start of the allowed range for the allocation | |
552 | * @end: end of the allowed range for the allocation | |
d935cc61 DV |
553 | * |
554 | * This simply sets up the scanning routines with the parameters for the desired | |
e18c0412 DV |
555 | * hole. Note that there's no need to specify allocation flags, since they only |
556 | * change the place a node is allocated from within a suitable hole. | |
d935cc61 | 557 | * |
e18c0412 DV |
558 | * Warning: |
559 | * As long as the scan list is non-empty, no other operations than | |
d935cc61 DV |
560 | * adding/removing nodes to/from the scan list are allowed. |
561 | */ | |
6b9d89b4 CW |
562 | void drm_mm_init_scan_with_range(struct drm_mm *mm, |
563 | unsigned long size, | |
d935cc61 | 564 | unsigned alignment, |
6b9d89b4 | 565 | unsigned long color, |
d935cc61 DV |
566 | unsigned long start, |
567 | unsigned long end) | |
568 | { | |
6b9d89b4 | 569 | mm->scan_color = color; |
d935cc61 DV |
570 | mm->scan_alignment = alignment; |
571 | mm->scan_size = size; | |
572 | mm->scanned_blocks = 0; | |
573 | mm->scan_hit_start = 0; | |
901593f2 | 574 | mm->scan_hit_end = 0; |
d935cc61 DV |
575 | mm->scan_start = start; |
576 | mm->scan_end = end; | |
577 | mm->scan_check_range = 1; | |
ae0cec28 | 578 | mm->prev_scanned_node = NULL; |
d935cc61 DV |
579 | } |
580 | EXPORT_SYMBOL(drm_mm_init_scan_with_range); | |
581 | ||
709ea971 | 582 | /** |
e18c0412 DV |
583 | * drm_mm_scan_add_block - add a node to the scan list |
584 | * @node: drm_mm_node to add | |
585 | * | |
709ea971 DV |
586 | * Add a node to the scan list that might be freed to make space for the desired |
587 | * hole. | |
588 | * | |
e18c0412 DV |
589 | * Returns: |
590 | * True if a hole has been found, false otherwise. | |
709ea971 | 591 | */ |
e18c0412 | 592 | bool drm_mm_scan_add_block(struct drm_mm_node *node) |
709ea971 DV |
593 | { |
594 | struct drm_mm *mm = node->mm; | |
ea7b1dd4 DV |
595 | struct drm_mm_node *prev_node; |
596 | unsigned long hole_start, hole_end; | |
901593f2 | 597 | unsigned long adj_start, adj_end; |
709ea971 DV |
598 | |
599 | mm->scanned_blocks++; | |
600 | ||
ea7b1dd4 | 601 | BUG_ON(node->scanned_block); |
709ea971 | 602 | node->scanned_block = 1; |
709ea971 | 603 | |
ea7b1dd4 DV |
604 | prev_node = list_entry(node->node_list.prev, struct drm_mm_node, |
605 | node_list); | |
709ea971 | 606 | |
ea7b1dd4 DV |
607 | node->scanned_preceeds_hole = prev_node->hole_follows; |
608 | prev_node->hole_follows = 1; | |
609 | list_del(&node->node_list); | |
610 | node->node_list.prev = &prev_node->node_list; | |
ae0cec28 DV |
611 | node->node_list.next = &mm->prev_scanned_node->node_list; |
612 | mm->prev_scanned_node = node; | |
709ea971 | 613 | |
901593f2 CW |
614 | adj_start = hole_start = drm_mm_hole_node_start(prev_node); |
615 | adj_end = hole_end = drm_mm_hole_node_end(prev_node); | |
6b9d89b4 | 616 | |
d935cc61 | 617 | if (mm->scan_check_range) { |
6b9d89b4 CW |
618 | if (adj_start < mm->scan_start) |
619 | adj_start = mm->scan_start; | |
620 | if (adj_end > mm->scan_end) | |
621 | adj_end = mm->scan_end; | |
d935cc61 DV |
622 | } |
623 | ||
901593f2 CW |
624 | if (mm->color_adjust) |
625 | mm->color_adjust(prev_node, mm->scan_color, | |
626 | &adj_start, &adj_end); | |
627 | ||
6b9d89b4 | 628 | if (check_free_hole(adj_start, adj_end, |
75214733 | 629 | mm->scan_size, mm->scan_alignment)) { |
ea7b1dd4 | 630 | mm->scan_hit_start = hole_start; |
901593f2 | 631 | mm->scan_hit_end = hole_end; |
e18c0412 | 632 | return true; |
709ea971 DV |
633 | } |
634 | ||
e18c0412 | 635 | return false; |
709ea971 DV |
636 | } |
637 | EXPORT_SYMBOL(drm_mm_scan_add_block); | |
638 | ||
639 | /** | |
e18c0412 DV |
640 | * drm_mm_scan_remove_block - remove a node from the scan list |
641 | * @node: drm_mm_node to remove | |
709ea971 DV |
642 | * |
643 | * Nodes _must_ be removed in the exact same order from the scan list as they | |
644 | * have been added, otherwise the internal state of the memory manager will be | |
645 | * corrupted. | |
646 | * | |
647 | * When the scan list is empty, the selected memory nodes can be freed. An | |
31e5d7c6 DH |
648 | * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then |
649 | * return the just freed block (because its at the top of the free_stack list). | |
709ea971 | 650 | * |
e18c0412 DV |
651 | * Returns: |
652 | * True if this block should be evicted, false otherwise. Will always | |
653 | * return false when no hole has been found. | |
709ea971 | 654 | */ |
e18c0412 | 655 | bool drm_mm_scan_remove_block(struct drm_mm_node *node) |
709ea971 DV |
656 | { |
657 | struct drm_mm *mm = node->mm; | |
ea7b1dd4 | 658 | struct drm_mm_node *prev_node; |
709ea971 DV |
659 | |
660 | mm->scanned_blocks--; | |
661 | ||
662 | BUG_ON(!node->scanned_block); | |
663 | node->scanned_block = 0; | |
709ea971 | 664 | |
ea7b1dd4 DV |
665 | prev_node = list_entry(node->node_list.prev, struct drm_mm_node, |
666 | node_list); | |
709ea971 | 667 | |
ea7b1dd4 | 668 | prev_node->hole_follows = node->scanned_preceeds_hole; |
ea7b1dd4 | 669 | list_add(&node->node_list, &prev_node->node_list); |
709ea971 | 670 | |
901593f2 CW |
671 | return (drm_mm_hole_node_end(node) > mm->scan_hit_start && |
672 | node->start < mm->scan_hit_end); | |
709ea971 DV |
673 | } |
674 | EXPORT_SYMBOL(drm_mm_scan_remove_block); | |
675 | ||
e18c0412 DV |
676 | /** |
677 | * drm_mm_clean - checks whether an allocator is clean | |
678 | * @mm: drm_mm allocator to check | |
679 | * | |
680 | * Returns: | |
681 | * True if the allocator is completely free, false if there's still a node | |
682 | * allocated in it. | |
683 | */ | |
684 | bool drm_mm_clean(struct drm_mm * mm) | |
3a1bd924 | 685 | { |
ea7b1dd4 | 686 | struct list_head *head = &mm->head_node.node_list; |
3a1bd924 | 687 | |
1d58420b TH |
688 | return (head->next->next == head); |
689 | } | |
249d6048 | 690 | EXPORT_SYMBOL(drm_mm_clean); |
3a1bd924 | 691 | |
e18c0412 DV |
692 | /** |
693 | * drm_mm_init - initialize a drm-mm allocator | |
694 | * @mm: the drm_mm structure to initialize | |
695 | * @start: start of the range managed by @mm | |
696 | * @size: end of the range managed by @mm | |
697 | * | |
698 | * Note that @mm must be cleared to 0 before calling this function. | |
699 | */ | |
77ef8bbc | 700 | void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size) |
1d58420b | 701 | { |
ea7b1dd4 | 702 | INIT_LIST_HEAD(&mm->hole_stack); |
709ea971 | 703 | mm->scanned_blocks = 0; |
3a1bd924 | 704 | |
ea7b1dd4 DV |
705 | /* Clever trick to avoid a special case in the free hole tracking. */ |
706 | INIT_LIST_HEAD(&mm->head_node.node_list); | |
707 | INIT_LIST_HEAD(&mm->head_node.hole_stack); | |
708 | mm->head_node.hole_follows = 1; | |
709 | mm->head_node.scanned_block = 0; | |
710 | mm->head_node.scanned_prev_free = 0; | |
711 | mm->head_node.scanned_next_free = 0; | |
712 | mm->head_node.mm = mm; | |
713 | mm->head_node.start = start + size; | |
714 | mm->head_node.size = start - mm->head_node.start; | |
715 | list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack); | |
716 | ||
6b9d89b4 | 717 | mm->color_adjust = NULL; |
3a1bd924 | 718 | } |
673a394b | 719 | EXPORT_SYMBOL(drm_mm_init); |
3a1bd924 | 720 | |
e18c0412 DV |
721 | /** |
722 | * drm_mm_takedown - clean up a drm_mm allocator | |
723 | * @mm: drm_mm allocator to clean up | |
724 | * | |
725 | * Note that it is a bug to call this function on an allocator which is not | |
726 | * clean. | |
727 | */ | |
55910517 | 728 | void drm_mm_takedown(struct drm_mm * mm) |
3a1bd924 | 729 | { |
c700c67b DH |
730 | WARN(!list_empty(&mm->head_node.node_list), |
731 | "Memory manager not clean during takedown.\n"); | |
3a1bd924 | 732 | } |
f453ba04 | 733 | EXPORT_SYMBOL(drm_mm_takedown); |
fa8a1238 | 734 | |
2c54b133 DV |
735 | static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry, |
736 | const char *prefix) | |
99d7e48e | 737 | { |
ea7b1dd4 DV |
738 | unsigned long hole_start, hole_end, hole_size; |
739 | ||
2c54b133 DV |
740 | if (entry->hole_follows) { |
741 | hole_start = drm_mm_hole_node_start(entry); | |
742 | hole_end = drm_mm_hole_node_end(entry); | |
743 | hole_size = hole_end - hole_start; | |
ea7b1dd4 DV |
744 | printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n", |
745 | prefix, hole_start, hole_end, | |
746 | hole_size); | |
2c54b133 DV |
747 | return hole_size; |
748 | } | |
749 | ||
750 | return 0; | |
751 | } | |
752 | ||
e18c0412 DV |
753 | /** |
754 | * drm_mm_debug_table - dump allocator state to dmesg | |
755 | * @mm: drm_mm allocator to dump | |
756 | * @prefix: prefix to use for dumping to dmesg | |
757 | */ | |
2c54b133 DV |
758 | void drm_mm_debug_table(struct drm_mm *mm, const char *prefix) |
759 | { | |
760 | struct drm_mm_node *entry; | |
761 | unsigned long total_used = 0, total_free = 0, total = 0; | |
762 | ||
763 | total_free += drm_mm_debug_hole(&mm->head_node, prefix); | |
ea7b1dd4 DV |
764 | |
765 | drm_mm_for_each_node(entry, mm) { | |
766 | printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n", | |
99d7e48e | 767 | prefix, entry->start, entry->start + entry->size, |
ea7b1dd4 DV |
768 | entry->size); |
769 | total_used += entry->size; | |
2c54b133 | 770 | total_free += drm_mm_debug_hole(entry, prefix); |
99d7e48e | 771 | } |
ea7b1dd4 DV |
772 | total = total_free + total_used; |
773 | ||
774 | printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total, | |
99d7e48e JG |
775 | total_used, total_free); |
776 | } | |
777 | EXPORT_SYMBOL(drm_mm_debug_table); | |
778 | ||
fa8a1238 | 779 | #if defined(CONFIG_DEBUG_FS) |
3a359f0b | 780 | static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry) |
fa8a1238 | 781 | { |
ea7b1dd4 DV |
782 | unsigned long hole_start, hole_end, hole_size; |
783 | ||
3a359f0b DV |
784 | if (entry->hole_follows) { |
785 | hole_start = drm_mm_hole_node_start(entry); | |
786 | hole_end = drm_mm_hole_node_end(entry); | |
787 | hole_size = hole_end - hole_start; | |
ea7b1dd4 DV |
788 | seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n", |
789 | hole_start, hole_end, hole_size); | |
3a359f0b DV |
790 | return hole_size; |
791 | } | |
792 | ||
793 | return 0; | |
794 | } | |
795 | ||
e18c0412 DV |
796 | /** |
797 | * drm_mm_dump_table - dump allocator state to a seq_file | |
798 | * @m: seq_file to dump to | |
799 | * @mm: drm_mm allocator to dump | |
800 | */ | |
3a359f0b DV |
801 | int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm) |
802 | { | |
803 | struct drm_mm_node *entry; | |
804 | unsigned long total_used = 0, total_free = 0, total = 0; | |
805 | ||
806 | total_free += drm_mm_dump_hole(m, &mm->head_node); | |
ea7b1dd4 DV |
807 | |
808 | drm_mm_for_each_node(entry, mm) { | |
809 | seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n", | |
810 | entry->start, entry->start + entry->size, | |
811 | entry->size); | |
812 | total_used += entry->size; | |
3a359f0b | 813 | total_free += drm_mm_dump_hole(m, entry); |
fa8a1238 | 814 | } |
ea7b1dd4 DV |
815 | total = total_free + total_used; |
816 | ||
817 | seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free); | |
fa8a1238 DA |
818 | return 0; |
819 | } | |
820 | EXPORT_SYMBOL(drm_mm_dump_table); | |
821 | #endif |