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1/*
2 * Copyright (c) Red Hat Inc.
3
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
13 * of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors: Dave Airlie <airlied@redhat.com>
24 * Jerome Glisse <jglisse@redhat.com>
25 * Pauli Nieminen <suokkos@gmail.com>
26 */
27
28/* simple list based uncached page pool
29 * - Pool collects resently freed pages for reuse
30 * - Use page->lru to keep a free list
31 * - doesn't track currently in use pages
32 */
33
34#define pr_fmt(fmt) "[TTM] " fmt
35
36#include <linux/list.h>
37#include <linux/spinlock.h>
38#include <linux/highmem.h>
39#include <linux/mm_types.h>
40#include <linux/module.h>
41#include <linux/mm.h>
42#include <linux/seq_file.h> /* for seq_printf */
43#include <linux/slab.h>
44#include <linux/dma-mapping.h>
45
46#include <linux/atomic.h>
47
48#include <drm/ttm/ttm_bo_driver.h>
49#include <drm/ttm/ttm_page_alloc.h>
50
51#ifdef TTM_HAS_AGP
52#include <asm/agp.h>
53#endif
54
55#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *))
56#define SMALL_ALLOCATION 16
57#define FREE_ALL_PAGES (~0U)
58/* times are in msecs */
59#define PAGE_FREE_INTERVAL 1000
60
61/**
62 * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
63 *
64 * @lock: Protects the shared pool from concurrnet access. Must be used with
65 * irqsave/irqrestore variants because pool allocator maybe called from
66 * delayed work.
67 * @fill_lock: Prevent concurrent calls to fill.
68 * @list: Pool of free uc/wc pages for fast reuse.
69 * @gfp_flags: Flags to pass for alloc_page.
70 * @npages: Number of pages in pool.
71 */
72struct ttm_page_pool {
73 spinlock_t lock;
74 bool fill_lock;
75 struct list_head list;
76 gfp_t gfp_flags;
77 unsigned npages;
78 char *name;
79 unsigned long nfrees;
80 unsigned long nrefills;
81};
82
83/**
84 * Limits for the pool. They are handled without locks because only place where
85 * they may change is in sysfs store. They won't have immediate effect anyway
86 * so forcing serialization to access them is pointless.
87 */
88
89struct ttm_pool_opts {
90 unsigned alloc_size;
91 unsigned max_size;
92 unsigned small;
93};
94
95#define NUM_POOLS 4
96
97/**
98 * struct ttm_pool_manager - Holds memory pools for fst allocation
99 *
100 * Manager is read only object for pool code so it doesn't need locking.
101 *
102 * @free_interval: minimum number of jiffies between freeing pages from pool.
103 * @page_alloc_inited: reference counting for pool allocation.
104 * @work: Work that is used to shrink the pool. Work is only run when there is
105 * some pages to free.
106 * @small_allocation: Limit in number of pages what is small allocation.
107 *
108 * @pools: All pool objects in use.
109 **/
110struct ttm_pool_manager {
111 struct kobject kobj;
112 struct shrinker mm_shrink;
113 struct ttm_pool_opts options;
114
115 union {
116 struct ttm_page_pool pools[NUM_POOLS];
117 struct {
118 struct ttm_page_pool wc_pool;
119 struct ttm_page_pool uc_pool;
120 struct ttm_page_pool wc_pool_dma32;
121 struct ttm_page_pool uc_pool_dma32;
122 } ;
123 };
124};
125
126static struct attribute ttm_page_pool_max = {
127 .name = "pool_max_size",
128 .mode = S_IRUGO | S_IWUSR
129};
130static struct attribute ttm_page_pool_small = {
131 .name = "pool_small_allocation",
132 .mode = S_IRUGO | S_IWUSR
133};
134static struct attribute ttm_page_pool_alloc_size = {
135 .name = "pool_allocation_size",
136 .mode = S_IRUGO | S_IWUSR
137};
138
139static struct attribute *ttm_pool_attrs[] = {
140 &ttm_page_pool_max,
141 &ttm_page_pool_small,
142 &ttm_page_pool_alloc_size,
143 NULL
144};
145
146static void ttm_pool_kobj_release(struct kobject *kobj)
147{
148 struct ttm_pool_manager *m =
149 container_of(kobj, struct ttm_pool_manager, kobj);
150 kfree(m);
151}
152
153static ssize_t ttm_pool_store(struct kobject *kobj,
154 struct attribute *attr, const char *buffer, size_t size)
155{
156 struct ttm_pool_manager *m =
157 container_of(kobj, struct ttm_pool_manager, kobj);
158 int chars;
159 unsigned val;
160 chars = sscanf(buffer, "%u", &val);
161 if (chars == 0)
162 return size;
163
164 /* Convert kb to number of pages */
165 val = val / (PAGE_SIZE >> 10);
166
167 if (attr == &ttm_page_pool_max)
168 m->options.max_size = val;
169 else if (attr == &ttm_page_pool_small)
170 m->options.small = val;
171 else if (attr == &ttm_page_pool_alloc_size) {
172 if (val > NUM_PAGES_TO_ALLOC*8) {
173 pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
174 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
175 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
176 return size;
177 } else if (val > NUM_PAGES_TO_ALLOC) {
178 pr_warn("Setting allocation size to larger than %lu is not recommended\n",
179 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
180 }
181 m->options.alloc_size = val;
182 }
183
184 return size;
185}
186
187static ssize_t ttm_pool_show(struct kobject *kobj,
188 struct attribute *attr, char *buffer)
189{
190 struct ttm_pool_manager *m =
191 container_of(kobj, struct ttm_pool_manager, kobj);
192 unsigned val = 0;
193
194 if (attr == &ttm_page_pool_max)
195 val = m->options.max_size;
196 else if (attr == &ttm_page_pool_small)
197 val = m->options.small;
198 else if (attr == &ttm_page_pool_alloc_size)
199 val = m->options.alloc_size;
200
201 val = val * (PAGE_SIZE >> 10);
202
203 return snprintf(buffer, PAGE_SIZE, "%u\n", val);
204}
205
206static const struct sysfs_ops ttm_pool_sysfs_ops = {
207 .show = &ttm_pool_show,
208 .store = &ttm_pool_store,
209};
210
211static struct kobj_type ttm_pool_kobj_type = {
212 .release = &ttm_pool_kobj_release,
213 .sysfs_ops = &ttm_pool_sysfs_ops,
214 .default_attrs = ttm_pool_attrs,
215};
216
217static struct ttm_pool_manager *_manager;
218
219#ifndef CONFIG_X86
220static int set_pages_array_wb(struct page **pages, int addrinarray)
221{
222#ifdef TTM_HAS_AGP
223 int i;
224
225 for (i = 0; i < addrinarray; i++)
226 unmap_page_from_agp(pages[i]);
227#endif
228 return 0;
229}
230
231static int set_pages_array_wc(struct page **pages, int addrinarray)
232{
233#ifdef TTM_HAS_AGP
234 int i;
235
236 for (i = 0; i < addrinarray; i++)
237 map_page_into_agp(pages[i]);
238#endif
239 return 0;
240}
241
242static int set_pages_array_uc(struct page **pages, int addrinarray)
243{
244#ifdef TTM_HAS_AGP
245 int i;
246
247 for (i = 0; i < addrinarray; i++)
248 map_page_into_agp(pages[i]);
249#endif
250 return 0;
251}
252#endif
253
254/**
255 * Select the right pool or requested caching state and ttm flags. */
256static struct ttm_page_pool *ttm_get_pool(int flags,
257 enum ttm_caching_state cstate)
258{
259 int pool_index;
260
261 if (cstate == tt_cached)
262 return NULL;
263
264 if (cstate == tt_wc)
265 pool_index = 0x0;
266 else
267 pool_index = 0x1;
268
269 if (flags & TTM_PAGE_FLAG_DMA32)
270 pool_index |= 0x2;
271
272 return &_manager->pools[pool_index];
273}
274
275/* set memory back to wb and free the pages. */
276static void ttm_pages_put(struct page *pages[], unsigned npages)
277{
278 unsigned i;
279 if (set_pages_array_wb(pages, npages))
280 pr_err("Failed to set %d pages to wb!\n", npages);
281 for (i = 0; i < npages; ++i)
282 __free_page(pages[i]);
283}
284
285static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
286 unsigned freed_pages)
287{
288 pool->npages -= freed_pages;
289 pool->nfrees += freed_pages;
290}
291
292/**
293 * Free pages from pool.
294 *
295 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
296 * number of pages in one go.
297 *
298 * @pool: to free the pages from
299 * @free_all: If set to true will free all pages in pool
300 * @use_static: Safe to use static buffer
301 **/
302static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free,
303 bool use_static)
304{
305 static struct page *static_buf[NUM_PAGES_TO_ALLOC];
306 unsigned long irq_flags;
307 struct page *p;
308 struct page **pages_to_free;
309 unsigned freed_pages = 0,
310 npages_to_free = nr_free;
311
312 if (NUM_PAGES_TO_ALLOC < nr_free)
313 npages_to_free = NUM_PAGES_TO_ALLOC;
314
315 if (use_static)
316 pages_to_free = static_buf;
317 else
318 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
319 GFP_KERNEL);
320 if (!pages_to_free) {
321 pr_err("Failed to allocate memory for pool free operation\n");
322 return 0;
323 }
324
325restart:
326 spin_lock_irqsave(&pool->lock, irq_flags);
327
328 list_for_each_entry_reverse(p, &pool->list, lru) {
329 if (freed_pages >= npages_to_free)
330 break;
331
332 pages_to_free[freed_pages++] = p;
333 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
334 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
335 /* remove range of pages from the pool */
336 __list_del(p->lru.prev, &pool->list);
337
338 ttm_pool_update_free_locked(pool, freed_pages);
339 /**
340 * Because changing page caching is costly
341 * we unlock the pool to prevent stalling.
342 */
343 spin_unlock_irqrestore(&pool->lock, irq_flags);
344
345 ttm_pages_put(pages_to_free, freed_pages);
346 if (likely(nr_free != FREE_ALL_PAGES))
347 nr_free -= freed_pages;
348
349 if (NUM_PAGES_TO_ALLOC >= nr_free)
350 npages_to_free = nr_free;
351 else
352 npages_to_free = NUM_PAGES_TO_ALLOC;
353
354 freed_pages = 0;
355
356 /* free all so restart the processing */
357 if (nr_free)
358 goto restart;
359
360 /* Not allowed to fall through or break because
361 * following context is inside spinlock while we are
362 * outside here.
363 */
364 goto out;
365
366 }
367 }
368
369 /* remove range of pages from the pool */
370 if (freed_pages) {
371 __list_del(&p->lru, &pool->list);
372
373 ttm_pool_update_free_locked(pool, freed_pages);
374 nr_free -= freed_pages;
375 }
376
377 spin_unlock_irqrestore(&pool->lock, irq_flags);
378
379 if (freed_pages)
380 ttm_pages_put(pages_to_free, freed_pages);
381out:
382 if (pages_to_free != static_buf)
383 kfree(pages_to_free);
384 return nr_free;
385}
386
387/**
388 * Callback for mm to request pool to reduce number of page held.
389 *
390 * XXX: (dchinner) Deadlock warning!
391 *
392 * This code is crying out for a shrinker per pool....
393 */
394static unsigned long
395ttm_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
396{
397 static DEFINE_MUTEX(lock);
398 static unsigned start_pool;
399 unsigned i;
400 unsigned pool_offset;
401 struct ttm_page_pool *pool;
402 int shrink_pages = sc->nr_to_scan;
403 unsigned long freed = 0;
404
405 if (!mutex_trylock(&lock))
406 return SHRINK_STOP;
407 pool_offset = ++start_pool % NUM_POOLS;
408 /* select start pool in round robin fashion */
409 for (i = 0; i < NUM_POOLS; ++i) {
410 unsigned nr_free = shrink_pages;
411 if (shrink_pages == 0)
412 break;
413 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
414 /* OK to use static buffer since global mutex is held. */
415 shrink_pages = ttm_page_pool_free(pool, nr_free, true);
416 freed += nr_free - shrink_pages;
417 }
418 mutex_unlock(&lock);
419 return freed;
420}
421
422
423static unsigned long
424ttm_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
425{
426 unsigned i;
427 unsigned long count = 0;
428
429 for (i = 0; i < NUM_POOLS; ++i)
430 count += _manager->pools[i].npages;
431
432 return count;
433}
434
435static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
436{
437 manager->mm_shrink.count_objects = ttm_pool_shrink_count;
438 manager->mm_shrink.scan_objects = ttm_pool_shrink_scan;
439 manager->mm_shrink.seeks = 1;
440 register_shrinker(&manager->mm_shrink);
441}
442
443static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
444{
445 unregister_shrinker(&manager->mm_shrink);
446}
447
448static int ttm_set_pages_caching(struct page **pages,
449 enum ttm_caching_state cstate, unsigned cpages)
450{
451 int r = 0;
452 /* Set page caching */
453 switch (cstate) {
454 case tt_uncached:
455 r = set_pages_array_uc(pages, cpages);
456 if (r)
457 pr_err("Failed to set %d pages to uc!\n", cpages);
458 break;
459 case tt_wc:
460 r = set_pages_array_wc(pages, cpages);
461 if (r)
462 pr_err("Failed to set %d pages to wc!\n", cpages);
463 break;
464 default:
465 break;
466 }
467 return r;
468}
469
470/**
471 * Free pages the pages that failed to change the caching state. If there is
472 * any pages that have changed their caching state already put them to the
473 * pool.
474 */
475static void ttm_handle_caching_state_failure(struct list_head *pages,
476 int ttm_flags, enum ttm_caching_state cstate,
477 struct page **failed_pages, unsigned cpages)
478{
479 unsigned i;
480 /* Failed pages have to be freed */
481 for (i = 0; i < cpages; ++i) {
482 list_del(&failed_pages[i]->lru);
483 __free_page(failed_pages[i]);
484 }
485}
486
487/**
488 * Allocate new pages with correct caching.
489 *
490 * This function is reentrant if caller updates count depending on number of
491 * pages returned in pages array.
492 */
493static int ttm_alloc_new_pages(struct list_head *pages, gfp_t gfp_flags,
494 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
495{
496 struct page **caching_array;
497 struct page *p;
498 int r = 0;
499 unsigned i, cpages;
500 unsigned max_cpages = min(count,
501 (unsigned)(PAGE_SIZE/sizeof(struct page *)));
502
503 /* allocate array for page caching change */
504 caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
505
506 if (!caching_array) {
507 pr_err("Unable to allocate table for new pages\n");
508 return -ENOMEM;
509 }
510
511 for (i = 0, cpages = 0; i < count; ++i) {
512 p = alloc_page(gfp_flags);
513
514 if (!p) {
515 pr_err("Unable to get page %u\n", i);
516
517 /* store already allocated pages in the pool after
518 * setting the caching state */
519 if (cpages) {
520 r = ttm_set_pages_caching(caching_array,
521 cstate, cpages);
522 if (r)
523 ttm_handle_caching_state_failure(pages,
524 ttm_flags, cstate,
525 caching_array, cpages);
526 }
527 r = -ENOMEM;
528 goto out;
529 }
530
531#ifdef CONFIG_HIGHMEM
532 /* gfp flags of highmem page should never be dma32 so we
533 * we should be fine in such case
534 */
535 if (!PageHighMem(p))
536#endif
537 {
538 caching_array[cpages++] = p;
539 if (cpages == max_cpages) {
540
541 r = ttm_set_pages_caching(caching_array,
542 cstate, cpages);
543 if (r) {
544 ttm_handle_caching_state_failure(pages,
545 ttm_flags, cstate,
546 caching_array, cpages);
547 goto out;
548 }
549 cpages = 0;
550 }
551 }
552
553 list_add(&p->lru, pages);
554 }
555
556 if (cpages) {
557 r = ttm_set_pages_caching(caching_array, cstate, cpages);
558 if (r)
559 ttm_handle_caching_state_failure(pages,
560 ttm_flags, cstate,
561 caching_array, cpages);
562 }
563out:
564 kfree(caching_array);
565
566 return r;
567}
568
569/**
570 * Fill the given pool if there aren't enough pages and the requested number of
571 * pages is small.
572 */
573static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
574 int ttm_flags, enum ttm_caching_state cstate, unsigned count,
575 unsigned long *irq_flags)
576{
577 struct page *p;
578 int r;
579 unsigned cpages = 0;
580 /**
581 * Only allow one pool fill operation at a time.
582 * If pool doesn't have enough pages for the allocation new pages are
583 * allocated from outside of pool.
584 */
585 if (pool->fill_lock)
586 return;
587
588 pool->fill_lock = true;
589
590 /* If allocation request is small and there are not enough
591 * pages in a pool we fill the pool up first. */
592 if (count < _manager->options.small
593 && count > pool->npages) {
594 struct list_head new_pages;
595 unsigned alloc_size = _manager->options.alloc_size;
596
597 /**
598 * Can't change page caching if in irqsave context. We have to
599 * drop the pool->lock.
600 */
601 spin_unlock_irqrestore(&pool->lock, *irq_flags);
602
603 INIT_LIST_HEAD(&new_pages);
604 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
605 cstate, alloc_size);
606 spin_lock_irqsave(&pool->lock, *irq_flags);
607
608 if (!r) {
609 list_splice(&new_pages, &pool->list);
610 ++pool->nrefills;
611 pool->npages += alloc_size;
612 } else {
613 pr_err("Failed to fill pool (%p)\n", pool);
614 /* If we have any pages left put them to the pool. */
615 list_for_each_entry(p, &pool->list, lru) {
616 ++cpages;
617 }
618 list_splice(&new_pages, &pool->list);
619 pool->npages += cpages;
620 }
621
622 }
623 pool->fill_lock = false;
624}
625
626/**
627 * Cut 'count' number of pages from the pool and put them on the return list.
628 *
629 * @return count of pages still required to fulfill the request.
630 */
631static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
632 struct list_head *pages,
633 int ttm_flags,
634 enum ttm_caching_state cstate,
635 unsigned count)
636{
637 unsigned long irq_flags;
638 struct list_head *p;
639 unsigned i;
640
641 spin_lock_irqsave(&pool->lock, irq_flags);
642 ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags);
643
644 if (count >= pool->npages) {
645 /* take all pages from the pool */
646 list_splice_init(&pool->list, pages);
647 count -= pool->npages;
648 pool->npages = 0;
649 goto out;
650 }
651 /* find the last pages to include for requested number of pages. Split
652 * pool to begin and halve it to reduce search space. */
653 if (count <= pool->npages/2) {
654 i = 0;
655 list_for_each(p, &pool->list) {
656 if (++i == count)
657 break;
658 }
659 } else {
660 i = pool->npages + 1;
661 list_for_each_prev(p, &pool->list) {
662 if (--i == count)
663 break;
664 }
665 }
666 /* Cut 'count' number of pages from the pool */
667 list_cut_position(pages, &pool->list, p);
668 pool->npages -= count;
669 count = 0;
670out:
671 spin_unlock_irqrestore(&pool->lock, irq_flags);
672 return count;
673}
674
675/* Put all pages in pages list to correct pool to wait for reuse */
676static void ttm_put_pages(struct page **pages, unsigned npages, int flags,
677 enum ttm_caching_state cstate)
678{
679 unsigned long irq_flags;
680 struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
681 unsigned i;
682
683 if (pool == NULL) {
684 /* No pool for this memory type so free the pages */
685 for (i = 0; i < npages; i++) {
686 if (pages[i]) {
687 if (page_count(pages[i]) != 1)
688 pr_err("Erroneous page count. Leaking pages.\n");
689 __free_page(pages[i]);
690 pages[i] = NULL;
691 }
692 }
693 return;
694 }
695
696 spin_lock_irqsave(&pool->lock, irq_flags);
697 for (i = 0; i < npages; i++) {
698 if (pages[i]) {
699 if (page_count(pages[i]) != 1)
700 pr_err("Erroneous page count. Leaking pages.\n");
701 list_add_tail(&pages[i]->lru, &pool->list);
702 pages[i] = NULL;
703 pool->npages++;
704 }
705 }
706 /* Check that we don't go over the pool limit */
707 npages = 0;
708 if (pool->npages > _manager->options.max_size) {
709 npages = pool->npages - _manager->options.max_size;
710 /* free at least NUM_PAGES_TO_ALLOC number of pages
711 * to reduce calls to set_memory_wb */
712 if (npages < NUM_PAGES_TO_ALLOC)
713 npages = NUM_PAGES_TO_ALLOC;
714 }
715 spin_unlock_irqrestore(&pool->lock, irq_flags);
716 if (npages)
717 ttm_page_pool_free(pool, npages, false);
718}
719
720/*
721 * On success pages list will hold count number of correctly
722 * cached pages.
723 */
724static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
725 enum ttm_caching_state cstate)
726{
727 struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
728 struct list_head plist;
729 struct page *p = NULL;
730 gfp_t gfp_flags = GFP_USER;
731 unsigned count;
732 int r;
733
734 /* set zero flag for page allocation if required */
735 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
736 gfp_flags |= __GFP_ZERO;
737
738 /* No pool for cached pages */
739 if (pool == NULL) {
740 if (flags & TTM_PAGE_FLAG_DMA32)
741 gfp_flags |= GFP_DMA32;
742 else
743 gfp_flags |= GFP_HIGHUSER;
744
745 for (r = 0; r < npages; ++r) {
746 p = alloc_page(gfp_flags);
747 if (!p) {
748
749 pr_err("Unable to allocate page\n");
750 return -ENOMEM;
751 }
752
753 pages[r] = p;
754 }
755 return 0;
756 }
757
758 /* combine zero flag to pool flags */
759 gfp_flags |= pool->gfp_flags;
760
761 /* First we take pages from the pool */
762 INIT_LIST_HEAD(&plist);
763 npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
764 count = 0;
765 list_for_each_entry(p, &plist, lru) {
766 pages[count++] = p;
767 }
768
769 /* clear the pages coming from the pool if requested */
770 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
771 list_for_each_entry(p, &plist, lru) {
772 if (PageHighMem(p))
773 clear_highpage(p);
774 else
775 clear_page(page_address(p));
776 }
777 }
778
779 /* If pool didn't have enough pages allocate new one. */
780 if (npages > 0) {
781 /* ttm_alloc_new_pages doesn't reference pool so we can run
782 * multiple requests in parallel.
783 **/
784 INIT_LIST_HEAD(&plist);
785 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate, npages);
786 list_for_each_entry(p, &plist, lru) {
787 pages[count++] = p;
788 }
789 if (r) {
790 /* If there is any pages in the list put them back to
791 * the pool. */
792 pr_err("Failed to allocate extra pages for large request\n");
793 ttm_put_pages(pages, count, flags, cstate);
794 return r;
795 }
796 }
797
798 return 0;
799}
800
801static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, gfp_t flags,
802 char *name)
803{
804 spin_lock_init(&pool->lock);
805 pool->fill_lock = false;
806 INIT_LIST_HEAD(&pool->list);
807 pool->npages = pool->nfrees = 0;
808 pool->gfp_flags = flags;
809 pool->name = name;
810}
811
812int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
813{
814 int ret;
815
816 WARN_ON(_manager);
817
818 pr_info("Initializing pool allocator\n");
819
820 _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
821
822 ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
823
824 ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc");
825
826 ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
827 GFP_USER | GFP_DMA32, "wc dma");
828
829 ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
830 GFP_USER | GFP_DMA32, "uc dma");
831
832 _manager->options.max_size = max_pages;
833 _manager->options.small = SMALL_ALLOCATION;
834 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
835
836 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
837 &glob->kobj, "pool");
838 if (unlikely(ret != 0)) {
839 kobject_put(&_manager->kobj);
840 _manager = NULL;
841 return ret;
842 }
843
844 ttm_pool_mm_shrink_init(_manager);
845
846 return 0;
847}
848
849void ttm_page_alloc_fini(void)
850{
851 int i;
852
853 pr_info("Finalizing pool allocator\n");
854 ttm_pool_mm_shrink_fini(_manager);
855
856 /* OK to use static buffer since global mutex is no longer used. */
857 for (i = 0; i < NUM_POOLS; ++i)
858 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES, true);
859
860 kobject_put(&_manager->kobj);
861 _manager = NULL;
862}
863
864int ttm_pool_populate(struct ttm_tt *ttm)
865{
866 struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
867 unsigned i;
868 int ret;
869
870 if (ttm->state != tt_unpopulated)
871 return 0;
872
873 for (i = 0; i < ttm->num_pages; ++i) {
874 ret = ttm_get_pages(&ttm->pages[i], 1,
875 ttm->page_flags,
876 ttm->caching_state);
877 if (ret != 0) {
878 ttm_pool_unpopulate(ttm);
879 return -ENOMEM;
880 }
881
882 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
883 false, false);
884 if (unlikely(ret != 0)) {
885 ttm_pool_unpopulate(ttm);
886 return -ENOMEM;
887 }
888 }
889
890 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
891 ret = ttm_tt_swapin(ttm);
892 if (unlikely(ret != 0)) {
893 ttm_pool_unpopulate(ttm);
894 return ret;
895 }
896 }
897
898 ttm->state = tt_unbound;
899 return 0;
900}
901EXPORT_SYMBOL(ttm_pool_populate);
902
903void ttm_pool_unpopulate(struct ttm_tt *ttm)
904{
905 unsigned i;
906
907 for (i = 0; i < ttm->num_pages; ++i) {
908 if (ttm->pages[i]) {
909 ttm_mem_global_free_page(ttm->glob->mem_glob,
910 ttm->pages[i]);
911 ttm_put_pages(&ttm->pages[i], 1,
912 ttm->page_flags,
913 ttm->caching_state);
914 }
915 }
916 ttm->state = tt_unpopulated;
917}
918EXPORT_SYMBOL(ttm_pool_unpopulate);
919
920int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
921{
922 struct ttm_page_pool *p;
923 unsigned i;
924 char *h[] = {"pool", "refills", "pages freed", "size"};
925 if (!_manager) {
926 seq_printf(m, "No pool allocator running.\n");
927 return 0;
928 }
929 seq_printf(m, "%6s %12s %13s %8s\n",
930 h[0], h[1], h[2], h[3]);
931 for (i = 0; i < NUM_POOLS; ++i) {
932 p = &_manager->pools[i];
933
934 seq_printf(m, "%6s %12ld %13ld %8d\n",
935 p->name, p->nrefills,
936 p->nfrees, p->npages);
937 }
938 return 0;
939}
940EXPORT_SYMBOL(ttm_page_alloc_debugfs);
1/*
2 * Copyright (c) Red Hat Inc.
3
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
13 * of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors: Dave Airlie <airlied@redhat.com>
24 * Jerome Glisse <jglisse@redhat.com>
25 * Pauli Nieminen <suokkos@gmail.com>
26 */
27
28/* simple list based uncached page pool
29 * - Pool collects resently freed pages for reuse
30 * - Use page->lru to keep a free list
31 * - doesn't track currently in use pages
32 */
33#include <linux/list.h>
34#include <linux/spinlock.h>
35#include <linux/highmem.h>
36#include <linux/mm_types.h>
37#include <linux/module.h>
38#include <linux/mm.h>
39#include <linux/seq_file.h> /* for seq_printf */
40#include <linux/slab.h>
41#include <linux/dma-mapping.h>
42
43#include <linux/atomic.h>
44
45#include "ttm/ttm_bo_driver.h"
46#include "ttm/ttm_page_alloc.h"
47
48#ifdef TTM_HAS_AGP
49#include <asm/agp.h>
50#endif
51
52#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *))
53#define SMALL_ALLOCATION 16
54#define FREE_ALL_PAGES (~0U)
55/* times are in msecs */
56#define PAGE_FREE_INTERVAL 1000
57
58/**
59 * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
60 *
61 * @lock: Protects the shared pool from concurrnet access. Must be used with
62 * irqsave/irqrestore variants because pool allocator maybe called from
63 * delayed work.
64 * @fill_lock: Prevent concurrent calls to fill.
65 * @list: Pool of free uc/wc pages for fast reuse.
66 * @gfp_flags: Flags to pass for alloc_page.
67 * @npages: Number of pages in pool.
68 */
69struct ttm_page_pool {
70 spinlock_t lock;
71 bool fill_lock;
72 struct list_head list;
73 gfp_t gfp_flags;
74 unsigned npages;
75 char *name;
76 unsigned long nfrees;
77 unsigned long nrefills;
78};
79
80/**
81 * Limits for the pool. They are handled without locks because only place where
82 * they may change is in sysfs store. They won't have immediate effect anyway
83 * so forcing serialization to access them is pointless.
84 */
85
86struct ttm_pool_opts {
87 unsigned alloc_size;
88 unsigned max_size;
89 unsigned small;
90};
91
92#define NUM_POOLS 4
93
94/**
95 * struct ttm_pool_manager - Holds memory pools for fst allocation
96 *
97 * Manager is read only object for pool code so it doesn't need locking.
98 *
99 * @free_interval: minimum number of jiffies between freeing pages from pool.
100 * @page_alloc_inited: reference counting for pool allocation.
101 * @work: Work that is used to shrink the pool. Work is only run when there is
102 * some pages to free.
103 * @small_allocation: Limit in number of pages what is small allocation.
104 *
105 * @pools: All pool objects in use.
106 **/
107struct ttm_pool_manager {
108 struct kobject kobj;
109 struct shrinker mm_shrink;
110 struct ttm_pool_opts options;
111
112 union {
113 struct ttm_page_pool pools[NUM_POOLS];
114 struct {
115 struct ttm_page_pool wc_pool;
116 struct ttm_page_pool uc_pool;
117 struct ttm_page_pool wc_pool_dma32;
118 struct ttm_page_pool uc_pool_dma32;
119 } ;
120 };
121};
122
123static struct attribute ttm_page_pool_max = {
124 .name = "pool_max_size",
125 .mode = S_IRUGO | S_IWUSR
126};
127static struct attribute ttm_page_pool_small = {
128 .name = "pool_small_allocation",
129 .mode = S_IRUGO | S_IWUSR
130};
131static struct attribute ttm_page_pool_alloc_size = {
132 .name = "pool_allocation_size",
133 .mode = S_IRUGO | S_IWUSR
134};
135
136static struct attribute *ttm_pool_attrs[] = {
137 &ttm_page_pool_max,
138 &ttm_page_pool_small,
139 &ttm_page_pool_alloc_size,
140 NULL
141};
142
143static void ttm_pool_kobj_release(struct kobject *kobj)
144{
145 struct ttm_pool_manager *m =
146 container_of(kobj, struct ttm_pool_manager, kobj);
147 kfree(m);
148}
149
150static ssize_t ttm_pool_store(struct kobject *kobj,
151 struct attribute *attr, const char *buffer, size_t size)
152{
153 struct ttm_pool_manager *m =
154 container_of(kobj, struct ttm_pool_manager, kobj);
155 int chars;
156 unsigned val;
157 chars = sscanf(buffer, "%u", &val);
158 if (chars == 0)
159 return size;
160
161 /* Convert kb to number of pages */
162 val = val / (PAGE_SIZE >> 10);
163
164 if (attr == &ttm_page_pool_max)
165 m->options.max_size = val;
166 else if (attr == &ttm_page_pool_small)
167 m->options.small = val;
168 else if (attr == &ttm_page_pool_alloc_size) {
169 if (val > NUM_PAGES_TO_ALLOC*8) {
170 printk(KERN_ERR TTM_PFX
171 "Setting allocation size to %lu "
172 "is not allowed. Recommended size is "
173 "%lu\n",
174 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
175 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
176 return size;
177 } else if (val > NUM_PAGES_TO_ALLOC) {
178 printk(KERN_WARNING TTM_PFX
179 "Setting allocation size to "
180 "larger than %lu is not recommended.\n",
181 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
182 }
183 m->options.alloc_size = val;
184 }
185
186 return size;
187}
188
189static ssize_t ttm_pool_show(struct kobject *kobj,
190 struct attribute *attr, char *buffer)
191{
192 struct ttm_pool_manager *m =
193 container_of(kobj, struct ttm_pool_manager, kobj);
194 unsigned val = 0;
195
196 if (attr == &ttm_page_pool_max)
197 val = m->options.max_size;
198 else if (attr == &ttm_page_pool_small)
199 val = m->options.small;
200 else if (attr == &ttm_page_pool_alloc_size)
201 val = m->options.alloc_size;
202
203 val = val * (PAGE_SIZE >> 10);
204
205 return snprintf(buffer, PAGE_SIZE, "%u\n", val);
206}
207
208static const struct sysfs_ops ttm_pool_sysfs_ops = {
209 .show = &ttm_pool_show,
210 .store = &ttm_pool_store,
211};
212
213static struct kobj_type ttm_pool_kobj_type = {
214 .release = &ttm_pool_kobj_release,
215 .sysfs_ops = &ttm_pool_sysfs_ops,
216 .default_attrs = ttm_pool_attrs,
217};
218
219static struct ttm_pool_manager *_manager;
220
221#ifndef CONFIG_X86
222static int set_pages_array_wb(struct page **pages, int addrinarray)
223{
224#ifdef TTM_HAS_AGP
225 int i;
226
227 for (i = 0; i < addrinarray; i++)
228 unmap_page_from_agp(pages[i]);
229#endif
230 return 0;
231}
232
233static int set_pages_array_wc(struct page **pages, int addrinarray)
234{
235#ifdef TTM_HAS_AGP
236 int i;
237
238 for (i = 0; i < addrinarray; i++)
239 map_page_into_agp(pages[i]);
240#endif
241 return 0;
242}
243
244static int set_pages_array_uc(struct page **pages, int addrinarray)
245{
246#ifdef TTM_HAS_AGP
247 int i;
248
249 for (i = 0; i < addrinarray; i++)
250 map_page_into_agp(pages[i]);
251#endif
252 return 0;
253}
254#endif
255
256/**
257 * Select the right pool or requested caching state and ttm flags. */
258static struct ttm_page_pool *ttm_get_pool(int flags,
259 enum ttm_caching_state cstate)
260{
261 int pool_index;
262
263 if (cstate == tt_cached)
264 return NULL;
265
266 if (cstate == tt_wc)
267 pool_index = 0x0;
268 else
269 pool_index = 0x1;
270
271 if (flags & TTM_PAGE_FLAG_DMA32)
272 pool_index |= 0x2;
273
274 return &_manager->pools[pool_index];
275}
276
277/* set memory back to wb and free the pages. */
278static void ttm_pages_put(struct page *pages[], unsigned npages)
279{
280 unsigned i;
281 if (set_pages_array_wb(pages, npages))
282 printk(KERN_ERR TTM_PFX "Failed to set %d pages to wb!\n",
283 npages);
284 for (i = 0; i < npages; ++i)
285 __free_page(pages[i]);
286}
287
288static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
289 unsigned freed_pages)
290{
291 pool->npages -= freed_pages;
292 pool->nfrees += freed_pages;
293}
294
295/**
296 * Free pages from pool.
297 *
298 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
299 * number of pages in one go.
300 *
301 * @pool: to free the pages from
302 * @free_all: If set to true will free all pages in pool
303 **/
304static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
305{
306 unsigned long irq_flags;
307 struct page *p;
308 struct page **pages_to_free;
309 unsigned freed_pages = 0,
310 npages_to_free = nr_free;
311
312 if (NUM_PAGES_TO_ALLOC < nr_free)
313 npages_to_free = NUM_PAGES_TO_ALLOC;
314
315 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
316 GFP_KERNEL);
317 if (!pages_to_free) {
318 printk(KERN_ERR TTM_PFX
319 "Failed to allocate memory for pool free operation.\n");
320 return 0;
321 }
322
323restart:
324 spin_lock_irqsave(&pool->lock, irq_flags);
325
326 list_for_each_entry_reverse(p, &pool->list, lru) {
327 if (freed_pages >= npages_to_free)
328 break;
329
330 pages_to_free[freed_pages++] = p;
331 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
332 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
333 /* remove range of pages from the pool */
334 __list_del(p->lru.prev, &pool->list);
335
336 ttm_pool_update_free_locked(pool, freed_pages);
337 /**
338 * Because changing page caching is costly
339 * we unlock the pool to prevent stalling.
340 */
341 spin_unlock_irqrestore(&pool->lock, irq_flags);
342
343 ttm_pages_put(pages_to_free, freed_pages);
344 if (likely(nr_free != FREE_ALL_PAGES))
345 nr_free -= freed_pages;
346
347 if (NUM_PAGES_TO_ALLOC >= nr_free)
348 npages_to_free = nr_free;
349 else
350 npages_to_free = NUM_PAGES_TO_ALLOC;
351
352 freed_pages = 0;
353
354 /* free all so restart the processing */
355 if (nr_free)
356 goto restart;
357
358 /* Not allowed to fall through or break because
359 * following context is inside spinlock while we are
360 * outside here.
361 */
362 goto out;
363
364 }
365 }
366
367 /* remove range of pages from the pool */
368 if (freed_pages) {
369 __list_del(&p->lru, &pool->list);
370
371 ttm_pool_update_free_locked(pool, freed_pages);
372 nr_free -= freed_pages;
373 }
374
375 spin_unlock_irqrestore(&pool->lock, irq_flags);
376
377 if (freed_pages)
378 ttm_pages_put(pages_to_free, freed_pages);
379out:
380 kfree(pages_to_free);
381 return nr_free;
382}
383
384/* Get good estimation how many pages are free in pools */
385static int ttm_pool_get_num_unused_pages(void)
386{
387 unsigned i;
388 int total = 0;
389 for (i = 0; i < NUM_POOLS; ++i)
390 total += _manager->pools[i].npages;
391
392 return total;
393}
394
395/**
396 * Callback for mm to request pool to reduce number of page held.
397 */
398static int ttm_pool_mm_shrink(struct shrinker *shrink,
399 struct shrink_control *sc)
400{
401 static atomic_t start_pool = ATOMIC_INIT(0);
402 unsigned i;
403 unsigned pool_offset = atomic_add_return(1, &start_pool);
404 struct ttm_page_pool *pool;
405 int shrink_pages = sc->nr_to_scan;
406
407 pool_offset = pool_offset % NUM_POOLS;
408 /* select start pool in round robin fashion */
409 for (i = 0; i < NUM_POOLS; ++i) {
410 unsigned nr_free = shrink_pages;
411 if (shrink_pages == 0)
412 break;
413 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
414 shrink_pages = ttm_page_pool_free(pool, nr_free);
415 }
416 /* return estimated number of unused pages in pool */
417 return ttm_pool_get_num_unused_pages();
418}
419
420static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
421{
422 manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
423 manager->mm_shrink.seeks = 1;
424 register_shrinker(&manager->mm_shrink);
425}
426
427static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
428{
429 unregister_shrinker(&manager->mm_shrink);
430}
431
432static int ttm_set_pages_caching(struct page **pages,
433 enum ttm_caching_state cstate, unsigned cpages)
434{
435 int r = 0;
436 /* Set page caching */
437 switch (cstate) {
438 case tt_uncached:
439 r = set_pages_array_uc(pages, cpages);
440 if (r)
441 printk(KERN_ERR TTM_PFX
442 "Failed to set %d pages to uc!\n",
443 cpages);
444 break;
445 case tt_wc:
446 r = set_pages_array_wc(pages, cpages);
447 if (r)
448 printk(KERN_ERR TTM_PFX
449 "Failed to set %d pages to wc!\n",
450 cpages);
451 break;
452 default:
453 break;
454 }
455 return r;
456}
457
458/**
459 * Free pages the pages that failed to change the caching state. If there is
460 * any pages that have changed their caching state already put them to the
461 * pool.
462 */
463static void ttm_handle_caching_state_failure(struct list_head *pages,
464 int ttm_flags, enum ttm_caching_state cstate,
465 struct page **failed_pages, unsigned cpages)
466{
467 unsigned i;
468 /* Failed pages have to be freed */
469 for (i = 0; i < cpages; ++i) {
470 list_del(&failed_pages[i]->lru);
471 __free_page(failed_pages[i]);
472 }
473}
474
475/**
476 * Allocate new pages with correct caching.
477 *
478 * This function is reentrant if caller updates count depending on number of
479 * pages returned in pages array.
480 */
481static int ttm_alloc_new_pages(struct list_head *pages, gfp_t gfp_flags,
482 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
483{
484 struct page **caching_array;
485 struct page *p;
486 int r = 0;
487 unsigned i, cpages;
488 unsigned max_cpages = min(count,
489 (unsigned)(PAGE_SIZE/sizeof(struct page *)));
490
491 /* allocate array for page caching change */
492 caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
493
494 if (!caching_array) {
495 printk(KERN_ERR TTM_PFX
496 "Unable to allocate table for new pages.");
497 return -ENOMEM;
498 }
499
500 for (i = 0, cpages = 0; i < count; ++i) {
501 p = alloc_page(gfp_flags);
502
503 if (!p) {
504 printk(KERN_ERR TTM_PFX "Unable to get page %u.\n", i);
505
506 /* store already allocated pages in the pool after
507 * setting the caching state */
508 if (cpages) {
509 r = ttm_set_pages_caching(caching_array,
510 cstate, cpages);
511 if (r)
512 ttm_handle_caching_state_failure(pages,
513 ttm_flags, cstate,
514 caching_array, cpages);
515 }
516 r = -ENOMEM;
517 goto out;
518 }
519
520#ifdef CONFIG_HIGHMEM
521 /* gfp flags of highmem page should never be dma32 so we
522 * we should be fine in such case
523 */
524 if (!PageHighMem(p))
525#endif
526 {
527 caching_array[cpages++] = p;
528 if (cpages == max_cpages) {
529
530 r = ttm_set_pages_caching(caching_array,
531 cstate, cpages);
532 if (r) {
533 ttm_handle_caching_state_failure(pages,
534 ttm_flags, cstate,
535 caching_array, cpages);
536 goto out;
537 }
538 cpages = 0;
539 }
540 }
541
542 list_add(&p->lru, pages);
543 }
544
545 if (cpages) {
546 r = ttm_set_pages_caching(caching_array, cstate, cpages);
547 if (r)
548 ttm_handle_caching_state_failure(pages,
549 ttm_flags, cstate,
550 caching_array, cpages);
551 }
552out:
553 kfree(caching_array);
554
555 return r;
556}
557
558/**
559 * Fill the given pool if there aren't enough pages and the requested number of
560 * pages is small.
561 */
562static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
563 int ttm_flags, enum ttm_caching_state cstate, unsigned count,
564 unsigned long *irq_flags)
565{
566 struct page *p;
567 int r;
568 unsigned cpages = 0;
569 /**
570 * Only allow one pool fill operation at a time.
571 * If pool doesn't have enough pages for the allocation new pages are
572 * allocated from outside of pool.
573 */
574 if (pool->fill_lock)
575 return;
576
577 pool->fill_lock = true;
578
579 /* If allocation request is small and there are not enough
580 * pages in a pool we fill the pool up first. */
581 if (count < _manager->options.small
582 && count > pool->npages) {
583 struct list_head new_pages;
584 unsigned alloc_size = _manager->options.alloc_size;
585
586 /**
587 * Can't change page caching if in irqsave context. We have to
588 * drop the pool->lock.
589 */
590 spin_unlock_irqrestore(&pool->lock, *irq_flags);
591
592 INIT_LIST_HEAD(&new_pages);
593 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
594 cstate, alloc_size);
595 spin_lock_irqsave(&pool->lock, *irq_flags);
596
597 if (!r) {
598 list_splice(&new_pages, &pool->list);
599 ++pool->nrefills;
600 pool->npages += alloc_size;
601 } else {
602 printk(KERN_ERR TTM_PFX
603 "Failed to fill pool (%p).", pool);
604 /* If we have any pages left put them to the pool. */
605 list_for_each_entry(p, &pool->list, lru) {
606 ++cpages;
607 }
608 list_splice(&new_pages, &pool->list);
609 pool->npages += cpages;
610 }
611
612 }
613 pool->fill_lock = false;
614}
615
616/**
617 * Cut 'count' number of pages from the pool and put them on the return list.
618 *
619 * @return count of pages still required to fulfill the request.
620 */
621static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
622 struct list_head *pages, int ttm_flags,
623 enum ttm_caching_state cstate, unsigned count)
624{
625 unsigned long irq_flags;
626 struct list_head *p;
627 unsigned i;
628
629 spin_lock_irqsave(&pool->lock, irq_flags);
630 ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags);
631
632 if (count >= pool->npages) {
633 /* take all pages from the pool */
634 list_splice_init(&pool->list, pages);
635 count -= pool->npages;
636 pool->npages = 0;
637 goto out;
638 }
639 /* find the last pages to include for requested number of pages. Split
640 * pool to begin and halve it to reduce search space. */
641 if (count <= pool->npages/2) {
642 i = 0;
643 list_for_each(p, &pool->list) {
644 if (++i == count)
645 break;
646 }
647 } else {
648 i = pool->npages + 1;
649 list_for_each_prev(p, &pool->list) {
650 if (--i == count)
651 break;
652 }
653 }
654 /* Cut 'count' number of pages from the pool */
655 list_cut_position(pages, &pool->list, p);
656 pool->npages -= count;
657 count = 0;
658out:
659 spin_unlock_irqrestore(&pool->lock, irq_flags);
660 return count;
661}
662
663/*
664 * On success pages list will hold count number of correctly
665 * cached pages.
666 */
667int ttm_get_pages(struct list_head *pages, int flags,
668 enum ttm_caching_state cstate, unsigned count,
669 dma_addr_t *dma_address)
670{
671 struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
672 struct page *p = NULL;
673 gfp_t gfp_flags = GFP_USER;
674 int r;
675
676 /* set zero flag for page allocation if required */
677 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
678 gfp_flags |= __GFP_ZERO;
679
680 /* No pool for cached pages */
681 if (pool == NULL) {
682 if (flags & TTM_PAGE_FLAG_DMA32)
683 gfp_flags |= GFP_DMA32;
684 else
685 gfp_flags |= GFP_HIGHUSER;
686
687 for (r = 0; r < count; ++r) {
688 p = alloc_page(gfp_flags);
689 if (!p) {
690
691 printk(KERN_ERR TTM_PFX
692 "Unable to allocate page.");
693 return -ENOMEM;
694 }
695
696 list_add(&p->lru, pages);
697 }
698 return 0;
699 }
700
701
702 /* combine zero flag to pool flags */
703 gfp_flags |= pool->gfp_flags;
704
705 /* First we take pages from the pool */
706 count = ttm_page_pool_get_pages(pool, pages, flags, cstate, count);
707
708 /* clear the pages coming from the pool if requested */
709 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
710 list_for_each_entry(p, pages, lru) {
711 clear_page(page_address(p));
712 }
713 }
714
715 /* If pool didn't have enough pages allocate new one. */
716 if (count > 0) {
717 /* ttm_alloc_new_pages doesn't reference pool so we can run
718 * multiple requests in parallel.
719 **/
720 r = ttm_alloc_new_pages(pages, gfp_flags, flags, cstate, count);
721 if (r) {
722 /* If there is any pages in the list put them back to
723 * the pool. */
724 printk(KERN_ERR TTM_PFX
725 "Failed to allocate extra pages "
726 "for large request.");
727 ttm_put_pages(pages, 0, flags, cstate, NULL);
728 return r;
729 }
730 }
731
732
733 return 0;
734}
735
736/* Put all pages in pages list to correct pool to wait for reuse */
737void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
738 enum ttm_caching_state cstate, dma_addr_t *dma_address)
739{
740 unsigned long irq_flags;
741 struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
742 struct page *p, *tmp;
743
744 if (pool == NULL) {
745 /* No pool for this memory type so free the pages */
746
747 list_for_each_entry_safe(p, tmp, pages, lru) {
748 __free_page(p);
749 }
750 /* Make the pages list empty */
751 INIT_LIST_HEAD(pages);
752 return;
753 }
754 if (page_count == 0) {
755 list_for_each_entry_safe(p, tmp, pages, lru) {
756 ++page_count;
757 }
758 }
759
760 spin_lock_irqsave(&pool->lock, irq_flags);
761 list_splice_init(pages, &pool->list);
762 pool->npages += page_count;
763 /* Check that we don't go over the pool limit */
764 page_count = 0;
765 if (pool->npages > _manager->options.max_size) {
766 page_count = pool->npages - _manager->options.max_size;
767 /* free at least NUM_PAGES_TO_ALLOC number of pages
768 * to reduce calls to set_memory_wb */
769 if (page_count < NUM_PAGES_TO_ALLOC)
770 page_count = NUM_PAGES_TO_ALLOC;
771 }
772 spin_unlock_irqrestore(&pool->lock, irq_flags);
773 if (page_count)
774 ttm_page_pool_free(pool, page_count);
775}
776
777static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
778 char *name)
779{
780 spin_lock_init(&pool->lock);
781 pool->fill_lock = false;
782 INIT_LIST_HEAD(&pool->list);
783 pool->npages = pool->nfrees = 0;
784 pool->gfp_flags = flags;
785 pool->name = name;
786}
787
788int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
789{
790 int ret;
791
792 WARN_ON(_manager);
793
794 printk(KERN_INFO TTM_PFX "Initializing pool allocator.\n");
795
796 _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
797
798 ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
799
800 ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc");
801
802 ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
803 GFP_USER | GFP_DMA32, "wc dma");
804
805 ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
806 GFP_USER | GFP_DMA32, "uc dma");
807
808 _manager->options.max_size = max_pages;
809 _manager->options.small = SMALL_ALLOCATION;
810 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
811
812 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
813 &glob->kobj, "pool");
814 if (unlikely(ret != 0)) {
815 kobject_put(&_manager->kobj);
816 _manager = NULL;
817 return ret;
818 }
819
820 ttm_pool_mm_shrink_init(_manager);
821
822 return 0;
823}
824
825void ttm_page_alloc_fini(void)
826{
827 int i;
828
829 printk(KERN_INFO TTM_PFX "Finalizing pool allocator.\n");
830 ttm_pool_mm_shrink_fini(_manager);
831
832 for (i = 0; i < NUM_POOLS; ++i)
833 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
834
835 kobject_put(&_manager->kobj);
836 _manager = NULL;
837}
838
839int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
840{
841 struct ttm_page_pool *p;
842 unsigned i;
843 char *h[] = {"pool", "refills", "pages freed", "size"};
844 if (!_manager) {
845 seq_printf(m, "No pool allocator running.\n");
846 return 0;
847 }
848 seq_printf(m, "%6s %12s %13s %8s\n",
849 h[0], h[1], h[2], h[3]);
850 for (i = 0; i < NUM_POOLS; ++i) {
851 p = &_manager->pools[i];
852
853 seq_printf(m, "%6s %12ld %13ld %8d\n",
854 p->name, p->nrefills,
855 p->nfrees, p->npages);
856 }
857 return 0;
858}
859EXPORT_SYMBOL(ttm_page_alloc_debugfs);