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ba4e7d97 TH |
1 | /************************************************************************** |
2 | * | |
3 | * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., 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 | #include "ttm/ttm_memory.h" | |
5fd9cbad | 29 | #include "ttm/ttm_module.h" |
ba4e7d97 TH |
30 | #include <linux/spinlock.h> |
31 | #include <linux/sched.h> | |
32 | #include <linux/wait.h> | |
33 | #include <linux/mm.h> | |
34 | #include <linux/module.h> | |
35 | ||
ba4e7d97 TH |
36 | #define TTM_MEMORY_ALLOC_RETRIES 4 |
37 | ||
5fd9cbad TH |
38 | struct ttm_mem_zone { |
39 | struct kobject kobj; | |
40 | struct ttm_mem_global *glob; | |
41 | const char *name; | |
42 | uint64_t zone_mem; | |
43 | uint64_t emer_mem; | |
44 | uint64_t max_mem; | |
45 | uint64_t swap_limit; | |
46 | uint64_t used_mem; | |
47 | }; | |
48 | ||
49 | static struct attribute ttm_mem_sys = { | |
50 | .name = "zone_memory", | |
51 | .mode = S_IRUGO | |
52 | }; | |
53 | static struct attribute ttm_mem_emer = { | |
54 | .name = "emergency_memory", | |
55 | .mode = S_IRUGO | S_IWUSR | |
56 | }; | |
57 | static struct attribute ttm_mem_max = { | |
58 | .name = "available_memory", | |
59 | .mode = S_IRUGO | S_IWUSR | |
60 | }; | |
61 | static struct attribute ttm_mem_swap = { | |
62 | .name = "swap_limit", | |
63 | .mode = S_IRUGO | S_IWUSR | |
64 | }; | |
65 | static struct attribute ttm_mem_used = { | |
66 | .name = "used_memory", | |
67 | .mode = S_IRUGO | |
68 | }; | |
69 | ||
70 | static void ttm_mem_zone_kobj_release(struct kobject *kobj) | |
71 | { | |
72 | struct ttm_mem_zone *zone = | |
73 | container_of(kobj, struct ttm_mem_zone, kobj); | |
74 | ||
75 | printk(KERN_INFO TTM_PFX | |
76 | "Zone %7s: Used memory at exit: %llu kiB.\n", | |
77 | zone->name, (unsigned long long) zone->used_mem >> 10); | |
78 | kfree(zone); | |
79 | } | |
80 | ||
81 | static ssize_t ttm_mem_zone_show(struct kobject *kobj, | |
82 | struct attribute *attr, | |
83 | char *buffer) | |
84 | { | |
85 | struct ttm_mem_zone *zone = | |
86 | container_of(kobj, struct ttm_mem_zone, kobj); | |
87 | uint64_t val = 0; | |
88 | ||
89 | spin_lock(&zone->glob->lock); | |
90 | if (attr == &ttm_mem_sys) | |
91 | val = zone->zone_mem; | |
92 | else if (attr == &ttm_mem_emer) | |
93 | val = zone->emer_mem; | |
94 | else if (attr == &ttm_mem_max) | |
95 | val = zone->max_mem; | |
96 | else if (attr == &ttm_mem_swap) | |
97 | val = zone->swap_limit; | |
98 | else if (attr == &ttm_mem_used) | |
99 | val = zone->used_mem; | |
100 | spin_unlock(&zone->glob->lock); | |
101 | ||
102 | return snprintf(buffer, PAGE_SIZE, "%llu\n", | |
103 | (unsigned long long) val >> 10); | |
104 | } | |
105 | ||
106 | static void ttm_check_swapping(struct ttm_mem_global *glob); | |
107 | ||
108 | static ssize_t ttm_mem_zone_store(struct kobject *kobj, | |
109 | struct attribute *attr, | |
110 | const char *buffer, | |
111 | size_t size) | |
112 | { | |
113 | struct ttm_mem_zone *zone = | |
114 | container_of(kobj, struct ttm_mem_zone, kobj); | |
115 | int chars; | |
116 | unsigned long val; | |
117 | uint64_t val64; | |
118 | ||
119 | chars = sscanf(buffer, "%lu", &val); | |
120 | if (chars == 0) | |
121 | return size; | |
122 | ||
123 | val64 = val; | |
124 | val64 <<= 10; | |
125 | ||
126 | spin_lock(&zone->glob->lock); | |
127 | if (val64 > zone->zone_mem) | |
128 | val64 = zone->zone_mem; | |
129 | if (attr == &ttm_mem_emer) { | |
130 | zone->emer_mem = val64; | |
131 | if (zone->max_mem > val64) | |
132 | zone->max_mem = val64; | |
133 | } else if (attr == &ttm_mem_max) { | |
134 | zone->max_mem = val64; | |
135 | if (zone->emer_mem < val64) | |
136 | zone->emer_mem = val64; | |
137 | } else if (attr == &ttm_mem_swap) | |
138 | zone->swap_limit = val64; | |
139 | spin_unlock(&zone->glob->lock); | |
140 | ||
141 | ttm_check_swapping(zone->glob); | |
142 | ||
143 | return size; | |
144 | } | |
145 | ||
146 | static struct attribute *ttm_mem_zone_attrs[] = { | |
147 | &ttm_mem_sys, | |
148 | &ttm_mem_emer, | |
149 | &ttm_mem_max, | |
150 | &ttm_mem_swap, | |
151 | &ttm_mem_used, | |
152 | NULL | |
153 | }; | |
154 | ||
155 | static struct sysfs_ops ttm_mem_zone_ops = { | |
156 | .show = &ttm_mem_zone_show, | |
157 | .store = &ttm_mem_zone_store | |
158 | }; | |
159 | ||
160 | static struct kobj_type ttm_mem_zone_kobj_type = { | |
161 | .release = &ttm_mem_zone_kobj_release, | |
162 | .sysfs_ops = &ttm_mem_zone_ops, | |
163 | .default_attrs = ttm_mem_zone_attrs, | |
164 | }; | |
165 | ||
166 | static void ttm_mem_global_kobj_release(struct kobject *kobj) | |
167 | { | |
168 | struct ttm_mem_global *glob = | |
169 | container_of(kobj, struct ttm_mem_global, kobj); | |
170 | ||
171 | kfree(glob); | |
172 | } | |
173 | ||
174 | static struct kobj_type ttm_mem_glob_kobj_type = { | |
175 | .release = &ttm_mem_global_kobj_release, | |
176 | }; | |
177 | ||
178 | static bool ttm_zones_above_swap_target(struct ttm_mem_global *glob, | |
179 | bool from_wq, uint64_t extra) | |
180 | { | |
181 | unsigned int i; | |
182 | struct ttm_mem_zone *zone; | |
183 | uint64_t target; | |
184 | ||
185 | for (i = 0; i < glob->num_zones; ++i) { | |
186 | zone = glob->zones[i]; | |
187 | ||
188 | if (from_wq) | |
189 | target = zone->swap_limit; | |
190 | else if (capable(CAP_SYS_ADMIN)) | |
191 | target = zone->emer_mem; | |
192 | else | |
193 | target = zone->max_mem; | |
194 | ||
195 | target = (extra > target) ? 0ULL : target; | |
196 | ||
197 | if (zone->used_mem > target) | |
198 | return true; | |
199 | } | |
200 | return false; | |
201 | } | |
202 | ||
ba4e7d97 TH |
203 | /** |
204 | * At this point we only support a single shrink callback. | |
205 | * Extend this if needed, perhaps using a linked list of callbacks. | |
206 | * Note that this function is reentrant: | |
207 | * many threads may try to swap out at any given time. | |
208 | */ | |
209 | ||
5fd9cbad | 210 | static void ttm_shrink(struct ttm_mem_global *glob, bool from_wq, |
ba4e7d97 TH |
211 | uint64_t extra) |
212 | { | |
213 | int ret; | |
214 | struct ttm_mem_shrink *shrink; | |
ba4e7d97 TH |
215 | |
216 | spin_lock(&glob->lock); | |
217 | if (glob->shrink == NULL) | |
218 | goto out; | |
219 | ||
5fd9cbad | 220 | while (ttm_zones_above_swap_target(glob, from_wq, extra)) { |
ba4e7d97 TH |
221 | shrink = glob->shrink; |
222 | spin_unlock(&glob->lock); | |
223 | ret = shrink->do_shrink(shrink); | |
224 | spin_lock(&glob->lock); | |
225 | if (unlikely(ret != 0)) | |
226 | goto out; | |
227 | } | |
228 | out: | |
229 | spin_unlock(&glob->lock); | |
230 | } | |
231 | ||
5fd9cbad TH |
232 | |
233 | ||
ba4e7d97 TH |
234 | static void ttm_shrink_work(struct work_struct *work) |
235 | { | |
236 | struct ttm_mem_global *glob = | |
237 | container_of(work, struct ttm_mem_global, work); | |
238 | ||
239 | ttm_shrink(glob, true, 0ULL); | |
240 | } | |
241 | ||
5fd9cbad TH |
242 | static int ttm_mem_init_kernel_zone(struct ttm_mem_global *glob, |
243 | const struct sysinfo *si) | |
244 | { | |
245 | struct ttm_mem_zone *zone = kzalloc(sizeof(*zone), GFP_KERNEL); | |
246 | uint64_t mem; | |
247 | ||
248 | if (unlikely(!zone)) | |
249 | return -ENOMEM; | |
250 | ||
251 | mem = si->totalram - si->totalhigh; | |
252 | mem *= si->mem_unit; | |
253 | ||
254 | zone->name = "kernel"; | |
255 | zone->zone_mem = mem; | |
256 | zone->max_mem = mem >> 1; | |
257 | zone->emer_mem = (mem >> 1) + (mem >> 2); | |
258 | zone->swap_limit = zone->max_mem - (mem >> 3); | |
259 | zone->used_mem = 0; | |
260 | zone->glob = glob; | |
261 | glob->zone_kernel = zone; | |
262 | glob->zones[glob->num_zones++] = zone; | |
263 | kobject_init(&zone->kobj, &ttm_mem_zone_kobj_type); | |
264 | return kobject_add(&zone->kobj, &glob->kobj, zone->name); | |
265 | } | |
266 | ||
267 | #ifdef CONFIG_HIGHMEM | |
268 | static int ttm_mem_init_highmem_zone(struct ttm_mem_global *glob, | |
269 | const struct sysinfo *si) | |
270 | { | |
271 | struct ttm_mem_zone *zone = kzalloc(sizeof(*zone), GFP_KERNEL); | |
272 | uint64_t mem; | |
273 | ||
274 | if (unlikely(!zone)) | |
275 | return -ENOMEM; | |
276 | ||
277 | if (si->totalhigh == 0) | |
278 | return 0; | |
279 | ||
280 | mem = si->totalram; | |
281 | mem *= si->mem_unit; | |
282 | ||
283 | zone->name = "highmem"; | |
284 | zone->zone_mem = mem; | |
285 | zone->max_mem = mem >> 1; | |
286 | zone->emer_mem = (mem >> 1) + (mem >> 2); | |
287 | zone->swap_limit = zone->max_mem - (mem >> 3); | |
288 | zone->used_mem = 0; | |
289 | zone->glob = glob; | |
290 | glob->zone_highmem = zone; | |
291 | glob->zones[glob->num_zones++] = zone; | |
292 | kobject_init(&zone->kobj, &ttm_mem_zone_kobj_type); | |
293 | return kobject_add(&zone->kobj, &glob->kobj, zone->name); | |
294 | } | |
295 | #else | |
296 | static int ttm_mem_init_dma32_zone(struct ttm_mem_global *glob, | |
297 | const struct sysinfo *si) | |
298 | { | |
299 | struct ttm_mem_zone *zone = kzalloc(sizeof(*zone), GFP_KERNEL); | |
300 | uint64_t mem; | |
301 | ||
302 | if (unlikely(!zone)) | |
303 | return -ENOMEM; | |
304 | ||
305 | mem = si->totalram; | |
306 | mem *= si->mem_unit; | |
307 | ||
308 | /** | |
309 | * No special dma32 zone needed. | |
310 | */ | |
311 | ||
312 | if (mem <= ((uint64_t) 1ULL << 32)) | |
313 | return 0; | |
314 | ||
315 | /* | |
316 | * Limit max dma32 memory to 4GB for now | |
317 | * until we can figure out how big this | |
318 | * zone really is. | |
319 | */ | |
320 | ||
321 | mem = ((uint64_t) 1ULL << 32); | |
322 | zone->name = "dma32"; | |
323 | zone->zone_mem = mem; | |
324 | zone->max_mem = mem >> 1; | |
325 | zone->emer_mem = (mem >> 1) + (mem >> 2); | |
326 | zone->swap_limit = zone->max_mem - (mem >> 3); | |
327 | zone->used_mem = 0; | |
328 | zone->glob = glob; | |
329 | glob->zone_dma32 = zone; | |
330 | glob->zones[glob->num_zones++] = zone; | |
331 | kobject_init(&zone->kobj, &ttm_mem_zone_kobj_type); | |
332 | return kobject_add(&zone->kobj, &glob->kobj, zone->name); | |
333 | } | |
334 | #endif | |
335 | ||
ba4e7d97 TH |
336 | int ttm_mem_global_init(struct ttm_mem_global *glob) |
337 | { | |
338 | struct sysinfo si; | |
5fd9cbad TH |
339 | int ret; |
340 | int i; | |
341 | struct ttm_mem_zone *zone; | |
ba4e7d97 TH |
342 | |
343 | spin_lock_init(&glob->lock); | |
344 | glob->swap_queue = create_singlethread_workqueue("ttm_swap"); | |
345 | INIT_WORK(&glob->work, ttm_shrink_work); | |
346 | init_waitqueue_head(&glob->queue); | |
5fd9cbad TH |
347 | kobject_init(&glob->kobj, &ttm_mem_glob_kobj_type); |
348 | ret = kobject_add(&glob->kobj, | |
349 | ttm_get_kobj(), | |
350 | "memory_accounting"); | |
351 | if (unlikely(ret != 0)) | |
352 | goto out_no_zone; | |
ba4e7d97 TH |
353 | |
354 | si_meminfo(&si); | |
355 | ||
5fd9cbad TH |
356 | ret = ttm_mem_init_kernel_zone(glob, &si); |
357 | if (unlikely(ret != 0)) | |
358 | goto out_no_zone; | |
359 | #ifdef CONFIG_HIGHMEM | |
360 | ret = ttm_mem_init_highmem_zone(glob, &si); | |
361 | if (unlikely(ret != 0)) | |
362 | goto out_no_zone; | |
363 | #else | |
364 | ret = ttm_mem_init_dma32_zone(glob, &si); | |
365 | if (unlikely(ret != 0)) | |
366 | goto out_no_zone; | |
367 | #endif | |
368 | for (i = 0; i < glob->num_zones; ++i) { | |
369 | zone = glob->zones[i]; | |
370 | printk(KERN_INFO TTM_PFX | |
371 | "Zone %7s: Available graphics memory: %llu kiB.\n", | |
372 | zone->name, (unsigned long long) zone->max_mem >> 10); | |
373 | } | |
ba4e7d97 | 374 | return 0; |
5fd9cbad TH |
375 | out_no_zone: |
376 | ttm_mem_global_release(glob); | |
377 | return ret; | |
ba4e7d97 TH |
378 | } |
379 | EXPORT_SYMBOL(ttm_mem_global_init); | |
380 | ||
381 | void ttm_mem_global_release(struct ttm_mem_global *glob) | |
382 | { | |
5fd9cbad TH |
383 | unsigned int i; |
384 | struct ttm_mem_zone *zone; | |
385 | ||
ba4e7d97 TH |
386 | flush_workqueue(glob->swap_queue); |
387 | destroy_workqueue(glob->swap_queue); | |
388 | glob->swap_queue = NULL; | |
5fd9cbad TH |
389 | for (i = 0; i < glob->num_zones; ++i) { |
390 | zone = glob->zones[i]; | |
391 | kobject_del(&zone->kobj); | |
392 | kobject_put(&zone->kobj); | |
393 | } | |
394 | kobject_del(&glob->kobj); | |
395 | kobject_put(&glob->kobj); | |
ba4e7d97 TH |
396 | } |
397 | EXPORT_SYMBOL(ttm_mem_global_release); | |
398 | ||
5fd9cbad | 399 | static void ttm_check_swapping(struct ttm_mem_global *glob) |
ba4e7d97 | 400 | { |
5fd9cbad TH |
401 | bool needs_swapping = false; |
402 | unsigned int i; | |
403 | struct ttm_mem_zone *zone; | |
ba4e7d97 TH |
404 | |
405 | spin_lock(&glob->lock); | |
5fd9cbad TH |
406 | for (i = 0; i < glob->num_zones; ++i) { |
407 | zone = glob->zones[i]; | |
408 | if (zone->used_mem > zone->swap_limit) { | |
409 | needs_swapping = true; | |
410 | break; | |
411 | } | |
412 | } | |
413 | ||
ba4e7d97 TH |
414 | spin_unlock(&glob->lock); |
415 | ||
416 | if (unlikely(needs_swapping)) | |
417 | (void)queue_work(glob->swap_queue, &glob->work); | |
418 | ||
419 | } | |
420 | ||
5fd9cbad TH |
421 | static void ttm_mem_global_free_zone(struct ttm_mem_global *glob, |
422 | struct ttm_mem_zone *single_zone, | |
423 | uint64_t amount) | |
ba4e7d97 | 424 | { |
5fd9cbad TH |
425 | unsigned int i; |
426 | struct ttm_mem_zone *zone; | |
427 | ||
ba4e7d97 | 428 | spin_lock(&glob->lock); |
5fd9cbad TH |
429 | for (i = 0; i < glob->num_zones; ++i) { |
430 | zone = glob->zones[i]; | |
431 | if (single_zone && zone != single_zone) | |
432 | continue; | |
433 | zone->used_mem -= amount; | |
434 | } | |
ba4e7d97 TH |
435 | spin_unlock(&glob->lock); |
436 | } | |
437 | ||
5fd9cbad TH |
438 | void ttm_mem_global_free(struct ttm_mem_global *glob, |
439 | uint64_t amount) | |
440 | { | |
441 | return ttm_mem_global_free_zone(glob, NULL, amount); | |
442 | } | |
443 | ||
ba4e7d97 | 444 | static int ttm_mem_global_reserve(struct ttm_mem_global *glob, |
5fd9cbad TH |
445 | struct ttm_mem_zone *single_zone, |
446 | uint64_t amount, bool reserve) | |
ba4e7d97 TH |
447 | { |
448 | uint64_t limit; | |
ba4e7d97 | 449 | int ret = -ENOMEM; |
5fd9cbad TH |
450 | unsigned int i; |
451 | struct ttm_mem_zone *zone; | |
ba4e7d97 TH |
452 | |
453 | spin_lock(&glob->lock); | |
5fd9cbad TH |
454 | for (i = 0; i < glob->num_zones; ++i) { |
455 | zone = glob->zones[i]; | |
456 | if (single_zone && zone != single_zone) | |
457 | continue; | |
ba4e7d97 | 458 | |
5fd9cbad TH |
459 | limit = (capable(CAP_SYS_ADMIN)) ? |
460 | zone->emer_mem : zone->max_mem; | |
ba4e7d97 | 461 | |
5fd9cbad TH |
462 | if (zone->used_mem > limit) |
463 | goto out_unlock; | |
464 | } | |
ba4e7d97 TH |
465 | |
466 | if (reserve) { | |
5fd9cbad TH |
467 | for (i = 0; i < glob->num_zones; ++i) { |
468 | zone = glob->zones[i]; | |
469 | if (single_zone && zone != single_zone) | |
470 | continue; | |
471 | zone->used_mem += amount; | |
472 | } | |
ba4e7d97 | 473 | } |
5fd9cbad | 474 | |
ba4e7d97 TH |
475 | ret = 0; |
476 | out_unlock: | |
477 | spin_unlock(&glob->lock); | |
478 | ttm_check_swapping(glob); | |
479 | ||
480 | return ret; | |
481 | } | |
482 | ||
5fd9cbad TH |
483 | |
484 | static int ttm_mem_global_alloc_zone(struct ttm_mem_global *glob, | |
485 | struct ttm_mem_zone *single_zone, | |
486 | uint64_t memory, | |
487 | bool no_wait, bool interruptible) | |
ba4e7d97 TH |
488 | { |
489 | int count = TTM_MEMORY_ALLOC_RETRIES; | |
490 | ||
5fd9cbad TH |
491 | while (unlikely(ttm_mem_global_reserve(glob, |
492 | single_zone, | |
493 | memory, true) | |
ba4e7d97 TH |
494 | != 0)) { |
495 | if (no_wait) | |
496 | return -ENOMEM; | |
497 | if (unlikely(count-- == 0)) | |
498 | return -ENOMEM; | |
499 | ttm_shrink(glob, false, memory + (memory >> 2) + 16); | |
500 | } | |
501 | ||
502 | return 0; | |
503 | } | |
504 | ||
5fd9cbad TH |
505 | int ttm_mem_global_alloc(struct ttm_mem_global *glob, uint64_t memory, |
506 | bool no_wait, bool interruptible) | |
507 | { | |
508 | /** | |
509 | * Normal allocations of kernel memory are registered in | |
510 | * all zones. | |
511 | */ | |
512 | ||
513 | return ttm_mem_global_alloc_zone(glob, NULL, memory, no_wait, | |
514 | interruptible); | |
515 | } | |
516 | ||
517 | int ttm_mem_global_alloc_page(struct ttm_mem_global *glob, | |
518 | struct page *page, | |
519 | bool no_wait, bool interruptible) | |
520 | { | |
521 | ||
522 | struct ttm_mem_zone *zone = NULL; | |
523 | ||
524 | /** | |
525 | * Page allocations may be registed in a single zone | |
526 | * only if highmem or !dma32. | |
527 | */ | |
528 | ||
529 | #ifdef CONFIG_HIGHMEM | |
530 | if (PageHighMem(page) && glob->zone_highmem != NULL) | |
531 | zone = glob->zone_highmem; | |
532 | #else | |
533 | if (glob->zone_dma32 && page_to_pfn(page) > 0x00100000UL) | |
534 | zone = glob->zone_kernel; | |
535 | #endif | |
536 | return ttm_mem_global_alloc_zone(glob, zone, PAGE_SIZE, no_wait, | |
537 | interruptible); | |
538 | } | |
539 | ||
540 | void ttm_mem_global_free_page(struct ttm_mem_global *glob, struct page *page) | |
541 | { | |
542 | struct ttm_mem_zone *zone = NULL; | |
543 | ||
544 | #ifdef CONFIG_HIGHMEM | |
545 | if (PageHighMem(page) && glob->zone_highmem != NULL) | |
546 | zone = glob->zone_highmem; | |
547 | #else | |
548 | if (glob->zone_dma32 && page_to_pfn(page) > 0x00100000UL) | |
549 | zone = glob->zone_kernel; | |
550 | #endif | |
551 | ttm_mem_global_free_zone(glob, zone, PAGE_SIZE); | |
552 | } | |
553 | ||
554 | ||
ba4e7d97 TH |
555 | size_t ttm_round_pot(size_t size) |
556 | { | |
557 | if ((size & (size - 1)) == 0) | |
558 | return size; | |
559 | else if (size > PAGE_SIZE) | |
560 | return PAGE_ALIGN(size); | |
561 | else { | |
562 | size_t tmp_size = 4; | |
563 | ||
564 | while (tmp_size < size) | |
565 | tmp_size <<= 1; | |
566 | ||
567 | return tmp_size; | |
568 | } | |
569 | return 0; | |
570 | } |