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