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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#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);
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);