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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
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#if IS_ENABLED(CONFIG_AGP)
52#include <asm/agp.h>
53#endif
54#ifdef CONFIG_X86
55#include <asm/set_memory.h>
56#endif
57
58#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *))
59#define SMALL_ALLOCATION 16
60#define FREE_ALL_PAGES (~0U)
61/* times are in msecs */
62#define PAGE_FREE_INTERVAL 1000
63
64/**
65 * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
66 *
67 * @lock: Protects the shared pool from concurrnet access. Must be used with
68 * irqsave/irqrestore variants because pool allocator maybe called from
69 * delayed work.
70 * @fill_lock: Prevent concurrent calls to fill.
71 * @list: Pool of free uc/wc pages for fast reuse.
72 * @gfp_flags: Flags to pass for alloc_page.
73 * @npages: Number of pages in pool.
74 */
75struct ttm_page_pool {
76 spinlock_t lock;
77 bool fill_lock;
78 struct list_head list;
79 gfp_t gfp_flags;
80 unsigned npages;
81 char *name;
82 unsigned long nfrees;
83 unsigned long nrefills;
84 unsigned int order;
85};
86
87/**
88 * Limits for the pool. They are handled without locks because only place where
89 * they may change is in sysfs store. They won't have immediate effect anyway
90 * so forcing serialization to access them is pointless.
91 */
92
93struct ttm_pool_opts {
94 unsigned alloc_size;
95 unsigned max_size;
96 unsigned small;
97};
98
99#define NUM_POOLS 6
100
101/**
102 * struct ttm_pool_manager - Holds memory pools for fst allocation
103 *
104 * Manager is read only object for pool code so it doesn't need locking.
105 *
106 * @free_interval: minimum number of jiffies between freeing pages from pool.
107 * @page_alloc_inited: reference counting for pool allocation.
108 * @work: Work that is used to shrink the pool. Work is only run when there is
109 * some pages to free.
110 * @small_allocation: Limit in number of pages what is small allocation.
111 *
112 * @pools: All pool objects in use.
113 **/
114struct ttm_pool_manager {
115 struct kobject kobj;
116 struct shrinker mm_shrink;
117 struct ttm_pool_opts options;
118
119 union {
120 struct ttm_page_pool pools[NUM_POOLS];
121 struct {
122 struct ttm_page_pool wc_pool;
123 struct ttm_page_pool uc_pool;
124 struct ttm_page_pool wc_pool_dma32;
125 struct ttm_page_pool uc_pool_dma32;
126 struct ttm_page_pool wc_pool_huge;
127 struct ttm_page_pool uc_pool_huge;
128 } ;
129 };
130};
131
132static struct attribute ttm_page_pool_max = {
133 .name = "pool_max_size",
134 .mode = S_IRUGO | S_IWUSR
135};
136static struct attribute ttm_page_pool_small = {
137 .name = "pool_small_allocation",
138 .mode = S_IRUGO | S_IWUSR
139};
140static struct attribute ttm_page_pool_alloc_size = {
141 .name = "pool_allocation_size",
142 .mode = S_IRUGO | S_IWUSR
143};
144
145static struct attribute *ttm_pool_attrs[] = {
146 &ttm_page_pool_max,
147 &ttm_page_pool_small,
148 &ttm_page_pool_alloc_size,
149 NULL
150};
151
152static void ttm_pool_kobj_release(struct kobject *kobj)
153{
154 struct ttm_pool_manager *m =
155 container_of(kobj, struct ttm_pool_manager, kobj);
156 kfree(m);
157}
158
159static ssize_t ttm_pool_store(struct kobject *kobj,
160 struct attribute *attr, const char *buffer, size_t size)
161{
162 struct ttm_pool_manager *m =
163 container_of(kobj, struct ttm_pool_manager, kobj);
164 int chars;
165 unsigned val;
166 chars = sscanf(buffer, "%u", &val);
167 if (chars == 0)
168 return size;
169
170 /* Convert kb to number of pages */
171 val = val / (PAGE_SIZE >> 10);
172
173 if (attr == &ttm_page_pool_max)
174 m->options.max_size = val;
175 else if (attr == &ttm_page_pool_small)
176 m->options.small = val;
177 else if (attr == &ttm_page_pool_alloc_size) {
178 if (val > NUM_PAGES_TO_ALLOC*8) {
179 pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
180 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
181 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
182 return size;
183 } else if (val > NUM_PAGES_TO_ALLOC) {
184 pr_warn("Setting allocation size to larger than %lu is not recommended\n",
185 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
186 }
187 m->options.alloc_size = val;
188 }
189
190 return size;
191}
192
193static ssize_t ttm_pool_show(struct kobject *kobj,
194 struct attribute *attr, char *buffer)
195{
196 struct ttm_pool_manager *m =
197 container_of(kobj, struct ttm_pool_manager, kobj);
198 unsigned val = 0;
199
200 if (attr == &ttm_page_pool_max)
201 val = m->options.max_size;
202 else if (attr == &ttm_page_pool_small)
203 val = m->options.small;
204 else if (attr == &ttm_page_pool_alloc_size)
205 val = m->options.alloc_size;
206
207 val = val * (PAGE_SIZE >> 10);
208
209 return snprintf(buffer, PAGE_SIZE, "%u\n", val);
210}
211
212static const struct sysfs_ops ttm_pool_sysfs_ops = {
213 .show = &ttm_pool_show,
214 .store = &ttm_pool_store,
215};
216
217static struct kobj_type ttm_pool_kobj_type = {
218 .release = &ttm_pool_kobj_release,
219 .sysfs_ops = &ttm_pool_sysfs_ops,
220 .default_attrs = ttm_pool_attrs,
221};
222
223static struct ttm_pool_manager *_manager;
224
225#ifndef CONFIG_X86
226static int set_pages_wb(struct page *page, int numpages)
227{
228#if IS_ENABLED(CONFIG_AGP)
229 int i;
230
231 for (i = 0; i < numpages; i++)
232 unmap_page_from_agp(page++);
233#endif
234 return 0;
235}
236
237static int set_pages_array_wb(struct page **pages, int addrinarray)
238{
239#if IS_ENABLED(CONFIG_AGP)
240 int i;
241
242 for (i = 0; i < addrinarray; i++)
243 unmap_page_from_agp(pages[i]);
244#endif
245 return 0;
246}
247
248static int set_pages_array_wc(struct page **pages, int addrinarray)
249{
250#if IS_ENABLED(CONFIG_AGP)
251 int i;
252
253 for (i = 0; i < addrinarray; i++)
254 map_page_into_agp(pages[i]);
255#endif
256 return 0;
257}
258
259static int set_pages_array_uc(struct page **pages, int addrinarray)
260{
261#if IS_ENABLED(CONFIG_AGP)
262 int i;
263
264 for (i = 0; i < addrinarray; i++)
265 map_page_into_agp(pages[i]);
266#endif
267 return 0;
268}
269#endif
270
271/**
272 * Select the right pool or requested caching state and ttm flags. */
273static struct ttm_page_pool *ttm_get_pool(int flags, bool huge,
274 enum ttm_caching_state cstate)
275{
276 int pool_index;
277
278 if (cstate == tt_cached)
279 return NULL;
280
281 if (cstate == tt_wc)
282 pool_index = 0x0;
283 else
284 pool_index = 0x1;
285
286 if (flags & TTM_PAGE_FLAG_DMA32) {
287 if (huge)
288 return NULL;
289 pool_index |= 0x2;
290
291 } else if (huge) {
292 pool_index |= 0x4;
293 }
294
295 return &_manager->pools[pool_index];
296}
297
298/* set memory back to wb and free the pages. */
299static void ttm_pages_put(struct page *pages[], unsigned npages,
300 unsigned int order)
301{
302 unsigned int i, pages_nr = (1 << order);
303
304 if (order == 0) {
305 if (set_pages_array_wb(pages, npages))
306 pr_err("Failed to set %d pages to wb!\n", npages);
307 }
308
309 for (i = 0; i < npages; ++i) {
310 if (order > 0) {
311 if (set_pages_wb(pages[i], pages_nr))
312 pr_err("Failed to set %d pages to wb!\n", pages_nr);
313 }
314 __free_pages(pages[i], order);
315 }
316}
317
318static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
319 unsigned freed_pages)
320{
321 pool->npages -= freed_pages;
322 pool->nfrees += freed_pages;
323}
324
325/**
326 * Free pages from pool.
327 *
328 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
329 * number of pages in one go.
330 *
331 * @pool: to free the pages from
332 * @free_all: If set to true will free all pages in pool
333 * @use_static: Safe to use static buffer
334 **/
335static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free,
336 bool use_static)
337{
338 static struct page *static_buf[NUM_PAGES_TO_ALLOC];
339 unsigned long irq_flags;
340 struct page *p;
341 struct page **pages_to_free;
342 unsigned freed_pages = 0,
343 npages_to_free = nr_free;
344
345 if (NUM_PAGES_TO_ALLOC < nr_free)
346 npages_to_free = NUM_PAGES_TO_ALLOC;
347
348 if (use_static)
349 pages_to_free = static_buf;
350 else
351 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
352 GFP_KERNEL);
353 if (!pages_to_free) {
354 pr_debug("Failed to allocate memory for pool free operation\n");
355 return 0;
356 }
357
358restart:
359 spin_lock_irqsave(&pool->lock, irq_flags);
360
361 list_for_each_entry_reverse(p, &pool->list, lru) {
362 if (freed_pages >= npages_to_free)
363 break;
364
365 pages_to_free[freed_pages++] = p;
366 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
367 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
368 /* remove range of pages from the pool */
369 __list_del(p->lru.prev, &pool->list);
370
371 ttm_pool_update_free_locked(pool, freed_pages);
372 /**
373 * Because changing page caching is costly
374 * we unlock the pool to prevent stalling.
375 */
376 spin_unlock_irqrestore(&pool->lock, irq_flags);
377
378 ttm_pages_put(pages_to_free, freed_pages, pool->order);
379 if (likely(nr_free != FREE_ALL_PAGES))
380 nr_free -= freed_pages;
381
382 if (NUM_PAGES_TO_ALLOC >= nr_free)
383 npages_to_free = nr_free;
384 else
385 npages_to_free = NUM_PAGES_TO_ALLOC;
386
387 freed_pages = 0;
388
389 /* free all so restart the processing */
390 if (nr_free)
391 goto restart;
392
393 /* Not allowed to fall through or break because
394 * following context is inside spinlock while we are
395 * outside here.
396 */
397 goto out;
398
399 }
400 }
401
402 /* remove range of pages from the pool */
403 if (freed_pages) {
404 __list_del(&p->lru, &pool->list);
405
406 ttm_pool_update_free_locked(pool, freed_pages);
407 nr_free -= freed_pages;
408 }
409
410 spin_unlock_irqrestore(&pool->lock, irq_flags);
411
412 if (freed_pages)
413 ttm_pages_put(pages_to_free, freed_pages, pool->order);
414out:
415 if (pages_to_free != static_buf)
416 kfree(pages_to_free);
417 return nr_free;
418}
419
420/**
421 * Callback for mm to request pool to reduce number of page held.
422 *
423 * XXX: (dchinner) Deadlock warning!
424 *
425 * This code is crying out for a shrinker per pool....
426 */
427static unsigned long
428ttm_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
429{
430 static DEFINE_MUTEX(lock);
431 static unsigned start_pool;
432 unsigned i;
433 unsigned pool_offset;
434 struct ttm_page_pool *pool;
435 int shrink_pages = sc->nr_to_scan;
436 unsigned long freed = 0;
437 unsigned int nr_free_pool;
438
439 if (!mutex_trylock(&lock))
440 return SHRINK_STOP;
441 pool_offset = ++start_pool % NUM_POOLS;
442 /* select start pool in round robin fashion */
443 for (i = 0; i < NUM_POOLS; ++i) {
444 unsigned nr_free = shrink_pages;
445 unsigned page_nr;
446
447 if (shrink_pages == 0)
448 break;
449
450 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
451 page_nr = (1 << pool->order);
452 /* OK to use static buffer since global mutex is held. */
453 nr_free_pool = roundup(nr_free, page_nr) >> pool->order;
454 shrink_pages = ttm_page_pool_free(pool, nr_free_pool, true);
455 freed += (nr_free_pool - shrink_pages) << pool->order;
456 if (freed >= sc->nr_to_scan)
457 break;
458 shrink_pages <<= pool->order;
459 }
460 mutex_unlock(&lock);
461 return freed;
462}
463
464
465static unsigned long
466ttm_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
467{
468 unsigned i;
469 unsigned long count = 0;
470 struct ttm_page_pool *pool;
471
472 for (i = 0; i < NUM_POOLS; ++i) {
473 pool = &_manager->pools[i];
474 count += (pool->npages << pool->order);
475 }
476
477 return count;
478}
479
480static int ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
481{
482 manager->mm_shrink.count_objects = ttm_pool_shrink_count;
483 manager->mm_shrink.scan_objects = ttm_pool_shrink_scan;
484 manager->mm_shrink.seeks = 1;
485 return register_shrinker(&manager->mm_shrink);
486}
487
488static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
489{
490 unregister_shrinker(&manager->mm_shrink);
491}
492
493static int ttm_set_pages_caching(struct page **pages,
494 enum ttm_caching_state cstate, unsigned cpages)
495{
496 int r = 0;
497 /* Set page caching */
498 switch (cstate) {
499 case tt_uncached:
500 r = set_pages_array_uc(pages, cpages);
501 if (r)
502 pr_err("Failed to set %d pages to uc!\n", cpages);
503 break;
504 case tt_wc:
505 r = set_pages_array_wc(pages, cpages);
506 if (r)
507 pr_err("Failed to set %d pages to wc!\n", cpages);
508 break;
509 default:
510 break;
511 }
512 return r;
513}
514
515/**
516 * Free pages the pages that failed to change the caching state. If there is
517 * any pages that have changed their caching state already put them to the
518 * pool.
519 */
520static void ttm_handle_caching_state_failure(struct list_head *pages,
521 int ttm_flags, enum ttm_caching_state cstate,
522 struct page **failed_pages, unsigned cpages)
523{
524 unsigned i;
525 /* Failed pages have to be freed */
526 for (i = 0; i < cpages; ++i) {
527 list_del(&failed_pages[i]->lru);
528 __free_page(failed_pages[i]);
529 }
530}
531
532/**
533 * Allocate new pages with correct caching.
534 *
535 * This function is reentrant if caller updates count depending on number of
536 * pages returned in pages array.
537 */
538static int ttm_alloc_new_pages(struct list_head *pages, gfp_t gfp_flags,
539 int ttm_flags, enum ttm_caching_state cstate,
540 unsigned count, unsigned order)
541{
542 struct page **caching_array;
543 struct page *p;
544 int r = 0;
545 unsigned i, j, cpages;
546 unsigned npages = 1 << order;
547 unsigned max_cpages = min(count << order, (unsigned)NUM_PAGES_TO_ALLOC);
548
549 /* allocate array for page caching change */
550 caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
551
552 if (!caching_array) {
553 pr_debug("Unable to allocate table for new pages\n");
554 return -ENOMEM;
555 }
556
557 for (i = 0, cpages = 0; i < count; ++i) {
558 p = alloc_pages(gfp_flags, order);
559
560 if (!p) {
561 pr_debug("Unable to get page %u\n", i);
562
563 /* store already allocated pages in the pool after
564 * setting the caching state */
565 if (cpages) {
566 r = ttm_set_pages_caching(caching_array,
567 cstate, cpages);
568 if (r)
569 ttm_handle_caching_state_failure(pages,
570 ttm_flags, cstate,
571 caching_array, cpages);
572 }
573 r = -ENOMEM;
574 goto out;
575 }
576
577 list_add(&p->lru, pages);
578
579#ifdef CONFIG_HIGHMEM
580 /* gfp flags of highmem page should never be dma32 so we
581 * we should be fine in such case
582 */
583 if (PageHighMem(p))
584 continue;
585
586#endif
587 for (j = 0; j < npages; ++j) {
588 caching_array[cpages++] = p++;
589 if (cpages == max_cpages) {
590
591 r = ttm_set_pages_caching(caching_array,
592 cstate, cpages);
593 if (r) {
594 ttm_handle_caching_state_failure(pages,
595 ttm_flags, cstate,
596 caching_array, cpages);
597 goto out;
598 }
599 cpages = 0;
600 }
601 }
602 }
603
604 if (cpages) {
605 r = ttm_set_pages_caching(caching_array, cstate, cpages);
606 if (r)
607 ttm_handle_caching_state_failure(pages,
608 ttm_flags, cstate,
609 caching_array, cpages);
610 }
611out:
612 kfree(caching_array);
613
614 return r;
615}
616
617/**
618 * Fill the given pool if there aren't enough pages and the requested number of
619 * pages is small.
620 */
621static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool, int ttm_flags,
622 enum ttm_caching_state cstate,
623 unsigned count, unsigned long *irq_flags)
624{
625 struct page *p;
626 int r;
627 unsigned cpages = 0;
628 /**
629 * Only allow one pool fill operation at a time.
630 * If pool doesn't have enough pages for the allocation new pages are
631 * allocated from outside of pool.
632 */
633 if (pool->fill_lock)
634 return;
635
636 pool->fill_lock = true;
637
638 /* If allocation request is small and there are not enough
639 * pages in a pool we fill the pool up first. */
640 if (count < _manager->options.small
641 && count > pool->npages) {
642 struct list_head new_pages;
643 unsigned alloc_size = _manager->options.alloc_size;
644
645 /**
646 * Can't change page caching if in irqsave context. We have to
647 * drop the pool->lock.
648 */
649 spin_unlock_irqrestore(&pool->lock, *irq_flags);
650
651 INIT_LIST_HEAD(&new_pages);
652 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
653 cstate, alloc_size, 0);
654 spin_lock_irqsave(&pool->lock, *irq_flags);
655
656 if (!r) {
657 list_splice(&new_pages, &pool->list);
658 ++pool->nrefills;
659 pool->npages += alloc_size;
660 } else {
661 pr_debug("Failed to fill pool (%p)\n", pool);
662 /* If we have any pages left put them to the pool. */
663 list_for_each_entry(p, &new_pages, lru) {
664 ++cpages;
665 }
666 list_splice(&new_pages, &pool->list);
667 pool->npages += cpages;
668 }
669
670 }
671 pool->fill_lock = false;
672}
673
674/**
675 * Allocate pages from the pool and put them on the return list.
676 *
677 * @return zero for success or negative error code.
678 */
679static int ttm_page_pool_get_pages(struct ttm_page_pool *pool,
680 struct list_head *pages,
681 int ttm_flags,
682 enum ttm_caching_state cstate,
683 unsigned count, unsigned order)
684{
685 unsigned long irq_flags;
686 struct list_head *p;
687 unsigned i;
688 int r = 0;
689
690 spin_lock_irqsave(&pool->lock, irq_flags);
691 if (!order)
692 ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count,
693 &irq_flags);
694
695 if (count >= pool->npages) {
696 /* take all pages from the pool */
697 list_splice_init(&pool->list, pages);
698 count -= pool->npages;
699 pool->npages = 0;
700 goto out;
701 }
702 /* find the last pages to include for requested number of pages. Split
703 * pool to begin and halve it to reduce search space. */
704 if (count <= pool->npages/2) {
705 i = 0;
706 list_for_each(p, &pool->list) {
707 if (++i == count)
708 break;
709 }
710 } else {
711 i = pool->npages + 1;
712 list_for_each_prev(p, &pool->list) {
713 if (--i == count)
714 break;
715 }
716 }
717 /* Cut 'count' number of pages from the pool */
718 list_cut_position(pages, &pool->list, p);
719 pool->npages -= count;
720 count = 0;
721out:
722 spin_unlock_irqrestore(&pool->lock, irq_flags);
723
724 /* clear the pages coming from the pool if requested */
725 if (ttm_flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
726 struct page *page;
727
728 list_for_each_entry(page, pages, lru) {
729 if (PageHighMem(page))
730 clear_highpage(page);
731 else
732 clear_page(page_address(page));
733 }
734 }
735
736 /* If pool didn't have enough pages allocate new one. */
737 if (count) {
738 gfp_t gfp_flags = pool->gfp_flags;
739
740 /* set zero flag for page allocation if required */
741 if (ttm_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
742 gfp_flags |= __GFP_ZERO;
743
744 if (ttm_flags & TTM_PAGE_FLAG_NO_RETRY)
745 gfp_flags |= __GFP_RETRY_MAYFAIL;
746
747 /* ttm_alloc_new_pages doesn't reference pool so we can run
748 * multiple requests in parallel.
749 **/
750 r = ttm_alloc_new_pages(pages, gfp_flags, ttm_flags, cstate,
751 count, order);
752 }
753
754 return r;
755}
756
757/* Put all pages in pages list to correct pool to wait for reuse */
758static void ttm_put_pages(struct page **pages, unsigned npages, int flags,
759 enum ttm_caching_state cstate)
760{
761 struct ttm_page_pool *pool = ttm_get_pool(flags, false, cstate);
762#ifdef CONFIG_TRANSPARENT_HUGEPAGE
763 struct ttm_page_pool *huge = ttm_get_pool(flags, true, cstate);
764#endif
765 unsigned long irq_flags;
766 unsigned i;
767
768 if (pool == NULL) {
769 /* No pool for this memory type so free the pages */
770 i = 0;
771 while (i < npages) {
772#ifdef CONFIG_TRANSPARENT_HUGEPAGE
773 struct page *p = pages[i];
774#endif
775 unsigned order = 0, j;
776
777 if (!pages[i]) {
778 ++i;
779 continue;
780 }
781
782#ifdef CONFIG_TRANSPARENT_HUGEPAGE
783 if (!(flags & TTM_PAGE_FLAG_DMA32)) {
784 for (j = 0; j < HPAGE_PMD_NR; ++j)
785 if (p++ != pages[i + j])
786 break;
787
788 if (j == HPAGE_PMD_NR)
789 order = HPAGE_PMD_ORDER;
790 }
791#endif
792
793 if (page_count(pages[i]) != 1)
794 pr_err("Erroneous page count. Leaking pages.\n");
795 __free_pages(pages[i], order);
796
797 j = 1 << order;
798 while (j) {
799 pages[i++] = NULL;
800 --j;
801 }
802 }
803 return;
804 }
805
806 i = 0;
807#ifdef CONFIG_TRANSPARENT_HUGEPAGE
808 if (huge) {
809 unsigned max_size, n2free;
810
811 spin_lock_irqsave(&huge->lock, irq_flags);
812 while (i < npages) {
813 struct page *p = pages[i];
814 unsigned j;
815
816 if (!p)
817 break;
818
819 for (j = 0; j < HPAGE_PMD_NR; ++j)
820 if (p++ != pages[i + j])
821 break;
822
823 if (j != HPAGE_PMD_NR)
824 break;
825
826 list_add_tail(&pages[i]->lru, &huge->list);
827
828 for (j = 0; j < HPAGE_PMD_NR; ++j)
829 pages[i++] = NULL;
830 huge->npages++;
831 }
832
833 /* Check that we don't go over the pool limit */
834 max_size = _manager->options.max_size;
835 max_size /= HPAGE_PMD_NR;
836 if (huge->npages > max_size)
837 n2free = huge->npages - max_size;
838 else
839 n2free = 0;
840 spin_unlock_irqrestore(&huge->lock, irq_flags);
841 if (n2free)
842 ttm_page_pool_free(huge, n2free, false);
843 }
844#endif
845
846 spin_lock_irqsave(&pool->lock, irq_flags);
847 while (i < npages) {
848 if (pages[i]) {
849 if (page_count(pages[i]) != 1)
850 pr_err("Erroneous page count. Leaking pages.\n");
851 list_add_tail(&pages[i]->lru, &pool->list);
852 pages[i] = NULL;
853 pool->npages++;
854 }
855 ++i;
856 }
857 /* Check that we don't go over the pool limit */
858 npages = 0;
859 if (pool->npages > _manager->options.max_size) {
860 npages = pool->npages - _manager->options.max_size;
861 /* free at least NUM_PAGES_TO_ALLOC number of pages
862 * to reduce calls to set_memory_wb */
863 if (npages < NUM_PAGES_TO_ALLOC)
864 npages = NUM_PAGES_TO_ALLOC;
865 }
866 spin_unlock_irqrestore(&pool->lock, irq_flags);
867 if (npages)
868 ttm_page_pool_free(pool, npages, false);
869}
870
871/*
872 * On success pages list will hold count number of correctly
873 * cached pages.
874 */
875static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
876 enum ttm_caching_state cstate)
877{
878 struct ttm_page_pool *pool = ttm_get_pool(flags, false, cstate);
879#ifdef CONFIG_TRANSPARENT_HUGEPAGE
880 struct ttm_page_pool *huge = ttm_get_pool(flags, true, cstate);
881#endif
882 struct list_head plist;
883 struct page *p = NULL;
884 unsigned count, first;
885 int r;
886
887 /* No pool for cached pages */
888 if (pool == NULL) {
889 gfp_t gfp_flags = GFP_USER;
890 unsigned i;
891#ifdef CONFIG_TRANSPARENT_HUGEPAGE
892 unsigned j;
893#endif
894
895 /* set zero flag for page allocation if required */
896 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
897 gfp_flags |= __GFP_ZERO;
898
899 if (flags & TTM_PAGE_FLAG_NO_RETRY)
900 gfp_flags |= __GFP_RETRY_MAYFAIL;
901
902 if (flags & TTM_PAGE_FLAG_DMA32)
903 gfp_flags |= GFP_DMA32;
904 else
905 gfp_flags |= GFP_HIGHUSER;
906
907 i = 0;
908#ifdef CONFIG_TRANSPARENT_HUGEPAGE
909 if (!(gfp_flags & GFP_DMA32)) {
910 while (npages >= HPAGE_PMD_NR) {
911 gfp_t huge_flags = gfp_flags;
912
913 huge_flags |= GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
914 __GFP_KSWAPD_RECLAIM;
915 huge_flags &= ~__GFP_MOVABLE;
916 huge_flags &= ~__GFP_COMP;
917 p = alloc_pages(huge_flags, HPAGE_PMD_ORDER);
918 if (!p)
919 break;
920
921 for (j = 0; j < HPAGE_PMD_NR; ++j)
922 pages[i++] = p++;
923
924 npages -= HPAGE_PMD_NR;
925 }
926 }
927#endif
928
929 first = i;
930 while (npages) {
931 p = alloc_page(gfp_flags);
932 if (!p) {
933 pr_debug("Unable to allocate page\n");
934 return -ENOMEM;
935 }
936
937 /* Swap the pages if we detect consecutive order */
938 if (i > first && pages[i - 1] == p - 1)
939 swap(p, pages[i - 1]);
940
941 pages[i++] = p;
942 --npages;
943 }
944 return 0;
945 }
946
947 count = 0;
948
949#ifdef CONFIG_TRANSPARENT_HUGEPAGE
950 if (huge && npages >= HPAGE_PMD_NR) {
951 INIT_LIST_HEAD(&plist);
952 ttm_page_pool_get_pages(huge, &plist, flags, cstate,
953 npages / HPAGE_PMD_NR,
954 HPAGE_PMD_ORDER);
955
956 list_for_each_entry(p, &plist, lru) {
957 unsigned j;
958
959 for (j = 0; j < HPAGE_PMD_NR; ++j)
960 pages[count++] = &p[j];
961 }
962 }
963#endif
964
965 INIT_LIST_HEAD(&plist);
966 r = ttm_page_pool_get_pages(pool, &plist, flags, cstate,
967 npages - count, 0);
968
969 first = count;
970 list_for_each_entry(p, &plist, lru) {
971 struct page *tmp = p;
972
973 /* Swap the pages if we detect consecutive order */
974 if (count > first && pages[count - 1] == tmp - 1)
975 swap(tmp, pages[count - 1]);
976 pages[count++] = tmp;
977 }
978
979 if (r) {
980 /* If there is any pages in the list put them back to
981 * the pool.
982 */
983 pr_debug("Failed to allocate extra pages for large request\n");
984 ttm_put_pages(pages, count, flags, cstate);
985 return r;
986 }
987
988 return 0;
989}
990
991static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, gfp_t flags,
992 char *name, unsigned int order)
993{
994 spin_lock_init(&pool->lock);
995 pool->fill_lock = false;
996 INIT_LIST_HEAD(&pool->list);
997 pool->npages = pool->nfrees = 0;
998 pool->gfp_flags = flags;
999 pool->name = name;
1000 pool->order = order;
1001}
1002
1003int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1004{
1005 int ret;
1006#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1007 unsigned order = HPAGE_PMD_ORDER;
1008#else
1009 unsigned order = 0;
1010#endif
1011
1012 WARN_ON(_manager);
1013
1014 pr_info("Initializing pool allocator\n");
1015
1016 _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1017 if (!_manager)
1018 return -ENOMEM;
1019
1020 ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc", 0);
1021
1022 ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc", 0);
1023
1024 ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
1025 GFP_USER | GFP_DMA32, "wc dma", 0);
1026
1027 ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
1028 GFP_USER | GFP_DMA32, "uc dma", 0);
1029
1030 ttm_page_pool_init_locked(&_manager->wc_pool_huge,
1031 (GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
1032 __GFP_KSWAPD_RECLAIM) &
1033 ~(__GFP_MOVABLE | __GFP_COMP),
1034 "wc huge", order);
1035
1036 ttm_page_pool_init_locked(&_manager->uc_pool_huge,
1037 (GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
1038 __GFP_KSWAPD_RECLAIM) &
1039 ~(__GFP_MOVABLE | __GFP_COMP)
1040 , "uc huge", order);
1041
1042 _manager->options.max_size = max_pages;
1043 _manager->options.small = SMALL_ALLOCATION;
1044 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1045
1046 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1047 &glob->kobj, "pool");
1048 if (unlikely(ret != 0))
1049 goto error;
1050
1051 ret = ttm_pool_mm_shrink_init(_manager);
1052 if (unlikely(ret != 0))
1053 goto error;
1054 return 0;
1055
1056error:
1057 kobject_put(&_manager->kobj);
1058 _manager = NULL;
1059 return ret;
1060}
1061
1062void ttm_page_alloc_fini(void)
1063{
1064 int i;
1065
1066 pr_info("Finalizing pool allocator\n");
1067 ttm_pool_mm_shrink_fini(_manager);
1068
1069 /* OK to use static buffer since global mutex is no longer used. */
1070 for (i = 0; i < NUM_POOLS; ++i)
1071 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES, true);
1072
1073 kobject_put(&_manager->kobj);
1074 _manager = NULL;
1075}
1076
1077static void
1078ttm_pool_unpopulate_helper(struct ttm_tt *ttm, unsigned mem_count_update)
1079{
1080 struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
1081 unsigned i;
1082
1083 if (mem_count_update == 0)
1084 goto put_pages;
1085
1086 for (i = 0; i < mem_count_update; ++i) {
1087 if (!ttm->pages[i])
1088 continue;
1089
1090 ttm_mem_global_free_page(mem_glob, ttm->pages[i], PAGE_SIZE);
1091 }
1092
1093put_pages:
1094 ttm_put_pages(ttm->pages, ttm->num_pages, ttm->page_flags,
1095 ttm->caching_state);
1096 ttm->state = tt_unpopulated;
1097}
1098
1099int ttm_pool_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
1100{
1101 struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
1102 unsigned i;
1103 int ret;
1104
1105 if (ttm->state != tt_unpopulated)
1106 return 0;
1107
1108 if (ttm_check_under_lowerlimit(mem_glob, ttm->num_pages, ctx))
1109 return -ENOMEM;
1110
1111 ret = ttm_get_pages(ttm->pages, ttm->num_pages, ttm->page_flags,
1112 ttm->caching_state);
1113 if (unlikely(ret != 0)) {
1114 ttm_pool_unpopulate_helper(ttm, 0);
1115 return ret;
1116 }
1117
1118 for (i = 0; i < ttm->num_pages; ++i) {
1119 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
1120 PAGE_SIZE, ctx);
1121 if (unlikely(ret != 0)) {
1122 ttm_pool_unpopulate_helper(ttm, i);
1123 return -ENOMEM;
1124 }
1125 }
1126
1127 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
1128 ret = ttm_tt_swapin(ttm);
1129 if (unlikely(ret != 0)) {
1130 ttm_pool_unpopulate(ttm);
1131 return ret;
1132 }
1133 }
1134
1135 ttm->state = tt_unbound;
1136 return 0;
1137}
1138EXPORT_SYMBOL(ttm_pool_populate);
1139
1140void ttm_pool_unpopulate(struct ttm_tt *ttm)
1141{
1142 ttm_pool_unpopulate_helper(ttm, ttm->num_pages);
1143}
1144EXPORT_SYMBOL(ttm_pool_unpopulate);
1145
1146int ttm_populate_and_map_pages(struct device *dev, struct ttm_dma_tt *tt,
1147 struct ttm_operation_ctx *ctx)
1148{
1149 unsigned i, j;
1150 int r;
1151
1152 r = ttm_pool_populate(&tt->ttm, ctx);
1153 if (r)
1154 return r;
1155
1156 for (i = 0; i < tt->ttm.num_pages; ++i) {
1157 struct page *p = tt->ttm.pages[i];
1158 size_t num_pages = 1;
1159
1160 for (j = i + 1; j < tt->ttm.num_pages; ++j) {
1161 if (++p != tt->ttm.pages[j])
1162 break;
1163
1164 ++num_pages;
1165 }
1166
1167 tt->dma_address[i] = dma_map_page(dev, tt->ttm.pages[i],
1168 0, num_pages * PAGE_SIZE,
1169 DMA_BIDIRECTIONAL);
1170 if (dma_mapping_error(dev, tt->dma_address[i])) {
1171 while (i--) {
1172 dma_unmap_page(dev, tt->dma_address[i],
1173 PAGE_SIZE, DMA_BIDIRECTIONAL);
1174 tt->dma_address[i] = 0;
1175 }
1176 ttm_pool_unpopulate(&tt->ttm);
1177 return -EFAULT;
1178 }
1179
1180 for (j = 1; j < num_pages; ++j) {
1181 tt->dma_address[i + 1] = tt->dma_address[i] + PAGE_SIZE;
1182 ++i;
1183 }
1184 }
1185 return 0;
1186}
1187EXPORT_SYMBOL(ttm_populate_and_map_pages);
1188
1189void ttm_unmap_and_unpopulate_pages(struct device *dev, struct ttm_dma_tt *tt)
1190{
1191 unsigned i, j;
1192
1193 for (i = 0; i < tt->ttm.num_pages;) {
1194 struct page *p = tt->ttm.pages[i];
1195 size_t num_pages = 1;
1196
1197 if (!tt->dma_address[i] || !tt->ttm.pages[i]) {
1198 ++i;
1199 continue;
1200 }
1201
1202 for (j = i + 1; j < tt->ttm.num_pages; ++j) {
1203 if (++p != tt->ttm.pages[j])
1204 break;
1205
1206 ++num_pages;
1207 }
1208
1209 dma_unmap_page(dev, tt->dma_address[i], num_pages * PAGE_SIZE,
1210 DMA_BIDIRECTIONAL);
1211
1212 i += num_pages;
1213 }
1214 ttm_pool_unpopulate(&tt->ttm);
1215}
1216EXPORT_SYMBOL(ttm_unmap_and_unpopulate_pages);
1217
1218int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
1219{
1220 struct ttm_page_pool *p;
1221 unsigned i;
1222 char *h[] = {"pool", "refills", "pages freed", "size"};
1223 if (!_manager) {
1224 seq_printf(m, "No pool allocator running.\n");
1225 return 0;
1226 }
1227 seq_printf(m, "%7s %12s %13s %8s\n",
1228 h[0], h[1], h[2], h[3]);
1229 for (i = 0; i < NUM_POOLS; ++i) {
1230 p = &_manager->pools[i];
1231
1232 seq_printf(m, "%7s %12ld %13ld %8d\n",
1233 p->name, p->nrefills,
1234 p->nfrees, p->npages);
1235 }
1236 return 0;
1237}
1238EXPORT_SYMBOL(ttm_page_alloc_debugfs);