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 * Copyright (c) 2013 The FreeBSD Foundation
29 * All rights reserved.
30 *
31 * Portions of this software were developed by Konstantin Belousov
32 * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
33 */
34
35 /* simple list based uncached page pool
36 * - Pool collects resently freed pages for reuse
37 * - Use page->lru to keep a free list
38 * - doesn't track currently in use pages
39 */
40
41 #define pr_fmt(fmt) "[TTM] " fmt
42
43 #include <linux/list.h>
44 #include <linux/spinlock.h>
45 #include <linux/highmem.h>
46 #include <linux/mm_types.h>
47 #include <linux/module.h>
48 #include <linux/mm.h>
49 #include <linux/seq_file.h> /* for seq_printf */
50 #include <linux/dma-mapping.h>
51
52 #include <linux/atomic.h>
53
54 #include <drm/ttm/ttm_bo_driver.h>
55 #include <drm/ttm/ttm_page_alloc.h>
56 #include <drm/ttm/ttm_set_memory.h>
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 */
75 struct ttm_page_pool {
76 struct lock lock;
77 bool fill_lock;
78 struct pglist 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
93 struct ttm_pool_opts {
94 unsigned alloc_size;
95 unsigned max_size;
96 unsigned small;
97 };
98
99 #define NUM_POOLS 4
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 **/
114 struct ttm_pool_manager {
115 struct kobject kobj;
116 struct shrinker mm_shrink;
117 eventhandler_tag lowmem_handler;
118 struct ttm_pool_opts options;
119
120 union {
121 struct ttm_page_pool pools[NUM_POOLS];
122 struct {
123 struct ttm_page_pool wc_pool;
124 struct ttm_page_pool uc_pool;
125 struct ttm_page_pool wc_pool_dma32;
126 struct ttm_page_pool uc_pool_dma32;
127 struct ttm_page_pool wc_pool_huge;
128 struct ttm_page_pool uc_pool_huge;
129 } ;
130 };
131 };
132
133 static struct attribute ttm_page_pool_max = {
134 .name = "pool_max_size",
135 .mode = S_IRUGO | S_IWUSR
136 };
137 static struct attribute ttm_page_pool_small = {
138 .name = "pool_small_allocation",
139 .mode = S_IRUGO | S_IWUSR
140 };
141 static struct attribute ttm_page_pool_alloc_size = {
142 .name = "pool_allocation_size",
143 .mode = S_IRUGO | S_IWUSR
144 };
145
146 static struct attribute *ttm_pool_attrs[] = {
147 &ttm_page_pool_max,
148 &ttm_page_pool_small,
149 &ttm_page_pool_alloc_size,
150 NULL
151 };
152
ttm_pool_kobj_release(struct kobject * kobj)153 static void ttm_pool_kobj_release(struct kobject *kobj)
154 {
155 struct ttm_pool_manager *m =
156 container_of(kobj, struct ttm_pool_manager, kobj);
157 kfree(m);
158 }
159
ttm_pool_store(struct kobject * kobj,struct attribute * attr,const char * buffer,size_t size)160 static ssize_t ttm_pool_store(struct kobject *kobj,
161 struct attribute *attr, const char *buffer, size_t size)
162 {
163 struct ttm_pool_manager *m =
164 container_of(kobj, struct ttm_pool_manager, kobj);
165 int chars;
166 unsigned val;
167 chars = ksscanf(buffer, "%u", &val);
168 if (chars == 0)
169 return size;
170
171 /* Convert kb to number of pages */
172 val = val / (PAGE_SIZE >> 10);
173
174 if (attr == &ttm_page_pool_max)
175 m->options.max_size = val;
176 else if (attr == &ttm_page_pool_small)
177 m->options.small = val;
178 else if (attr == &ttm_page_pool_alloc_size) {
179 if (val > NUM_PAGES_TO_ALLOC*8) {
180 pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
181 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
182 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
183 return size;
184 } else if (val > NUM_PAGES_TO_ALLOC) {
185 pr_warn("Setting allocation size to larger than %lu is not recommended\n",
186 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
187 }
188 m->options.alloc_size = val;
189 }
190
191 return size;
192 }
193
ttm_pool_show(struct kobject * kobj,struct attribute * attr,char * buffer)194 static ssize_t ttm_pool_show(struct kobject *kobj,
195 struct attribute *attr, char *buffer)
196 {
197 struct ttm_pool_manager *m =
198 container_of(kobj, struct ttm_pool_manager, kobj);
199 unsigned val = 0;
200
201 if (attr == &ttm_page_pool_max)
202 val = m->options.max_size;
203 else if (attr == &ttm_page_pool_small)
204 val = m->options.small;
205 else if (attr == &ttm_page_pool_alloc_size)
206 val = m->options.alloc_size;
207
208 val = val * (PAGE_SIZE >> 10);
209
210 return ksnprintf(buffer, PAGE_SIZE, "%u\n", val);
211 }
212
213 static const struct sysfs_ops ttm_pool_sysfs_ops = {
214 .show = &ttm_pool_show,
215 .store = &ttm_pool_store,
216 };
217
218 static struct kobj_type ttm_pool_kobj_type = {
219 .release = &ttm_pool_kobj_release,
220 .sysfs_ops = &ttm_pool_sysfs_ops,
221 .default_attrs = ttm_pool_attrs,
222 };
223
224 static struct ttm_pool_manager *_manager;
225
226 /**
227 * Select the right pool or requested caching state and ttm flags. */
ttm_get_pool(int flags,bool huge,enum ttm_caching_state cstate)228 static struct ttm_page_pool *ttm_get_pool(int flags, bool huge,
229 enum ttm_caching_state cstate)
230 {
231 int pool_index;
232
233 if (cstate == tt_cached)
234 return NULL;
235
236 if (cstate == tt_wc)
237 pool_index = 0x0;
238 else
239 pool_index = 0x1;
240
241 if (flags & TTM_PAGE_FLAG_DMA32) {
242 if (huge)
243 return NULL;
244 pool_index |= 0x2;
245
246 } else if (huge) {
247 pool_index |= 0x4;
248 }
249
250 return &_manager->pools[pool_index];
251 }
252
253 /* set memory back to wb and free the pages. */
ttm_pages_put(struct page * pages[],unsigned npages,unsigned int order)254 static void ttm_pages_put(struct page *pages[], unsigned npages,
255 unsigned int order)
256 {
257 unsigned int i, pages_nr = (1 << order);
258
259 if (order == 0) {
260 if (ttm_set_pages_array_wb(pages, npages))
261 pr_err("Failed to set %d pages to wb!\n", npages);
262 }
263
264 for (i = 0; i < npages; ++i) {
265 if (order > 0) {
266 if (ttm_set_pages_wb(pages[i], pages_nr))
267 pr_err("Failed to set %d pages to wb!\n", pages_nr);
268 }
269 __free_pages(pages[i], order);
270 }
271 }
272
ttm_pool_update_free_locked(struct ttm_page_pool * pool,unsigned freed_pages)273 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
274 unsigned freed_pages)
275 {
276 pool->npages -= freed_pages;
277 pool->nfrees += freed_pages;
278 }
279
280 /**
281 * Free pages from pool.
282 *
283 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
284 * number of pages in one go.
285 *
286 * @pool: to free the pages from
287 * @free_all: If set to true will free all pages in pool
288 * @use_static: Safe to use static buffer
289 **/
ttm_page_pool_free(struct ttm_page_pool * pool,unsigned nr_free,bool use_static)290 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free,
291 bool use_static)
292 {
293 static struct page *static_buf[NUM_PAGES_TO_ALLOC];
294 unsigned long irq_flags;
295 struct vm_page *p, *p1;
296 struct page **pages_to_free;
297 unsigned freed_pages = 0,
298 npages_to_free = nr_free;
299 unsigned i;
300
301 if (NUM_PAGES_TO_ALLOC < nr_free)
302 npages_to_free = NUM_PAGES_TO_ALLOC;
303
304 if (use_static)
305 pages_to_free = static_buf;
306 else
307 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
308 M_DRM, GFP_KERNEL);
309 if (!pages_to_free) {
310 pr_err("Failed to allocate memory for pool free operation\n");
311 return 0;
312 }
313
314 restart:
315 spin_lock_irqsave(&pool->lock, irq_flags);
316
317 TAILQ_FOREACH_REVERSE_MUTABLE(p, &pool->list, pglist, pageq, p1) {
318 if (freed_pages >= npages_to_free)
319 break;
320
321 pages_to_free[freed_pages++] = (struct page *)p;
322 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
323 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
324 /* remove range of pages from the pool */
325 for (i = 0; i < freed_pages; i++)
326 TAILQ_REMOVE(&pool->list, (struct vm_page *)pages_to_free[i], pageq);
327
328 ttm_pool_update_free_locked(pool, freed_pages);
329 /**
330 * Because changing page caching is costly
331 * we unlock the pool to prevent stalling.
332 */
333 spin_unlock_irqrestore(&pool->lock, irq_flags);
334
335 ttm_pages_put(pages_to_free, freed_pages, pool->order);
336 if (likely(nr_free != FREE_ALL_PAGES))
337 nr_free -= freed_pages;
338
339 if (NUM_PAGES_TO_ALLOC >= nr_free)
340 npages_to_free = nr_free;
341 else
342 npages_to_free = NUM_PAGES_TO_ALLOC;
343
344 freed_pages = 0;
345
346 /* free all so restart the processing */
347 if (nr_free)
348 goto restart;
349
350 /* Not allowed to fall through or break because
351 * following context is inside spinlock while we are
352 * outside here.
353 */
354 goto out;
355
356 }
357 }
358
359 /* remove range of pages from the pool */
360 if (freed_pages) {
361 for (i = 0; i < freed_pages; i++)
362 TAILQ_REMOVE(&pool->list, (struct vm_page *)pages_to_free[i], pageq);
363
364 ttm_pool_update_free_locked(pool, freed_pages);
365 nr_free -= freed_pages;
366 }
367
368 spin_unlock_irqrestore(&pool->lock, irq_flags);
369
370 if (freed_pages)
371 ttm_pages_put(pages_to_free, freed_pages, pool->order);
372 out:
373 if (pages_to_free != static_buf)
374 kfree(pages_to_free);
375 return nr_free;
376 }
377
378 /**
379 * Callback for mm to request pool to reduce number of page held.
380 *
381 * XXX: (dchinner) Deadlock warning!
382 *
383 * This code is crying out for a shrinker per pool....
384 */
385 static unsigned long
ttm_pool_shrink_scan(struct shrinker * shrink,struct shrink_control * sc)386 ttm_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
387 {
388 static DEFINE_MUTEX(lock);
389 static unsigned start_pool;
390 unsigned i;
391 unsigned pool_offset;
392 struct ttm_page_pool *pool;
393 int shrink_pages = 100; /* XXXKIB */
394 unsigned long freed = 0;
395 unsigned int nr_free_pool;
396
397 #ifdef __DragonFly__
398 sc->gfp_mask = M_WAITOK;
399 #endif
400
401 if (!mutex_trylock(&lock))
402 return SHRINK_STOP;
403 pool_offset = ++start_pool % NUM_POOLS;
404 /* select start pool in round robin fashion */
405 for (i = 0; i < NUM_POOLS; ++i) {
406 unsigned nr_free = shrink_pages;
407 unsigned page_nr;
408
409 if (shrink_pages == 0)
410 break;
411
412 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
413 page_nr = (1 << pool->order);
414 /* OK to use static buffer since global mutex is held. */
415 nr_free_pool = roundup(nr_free, page_nr) >> pool->order;
416 shrink_pages = ttm_page_pool_free(pool, nr_free_pool, true);
417 freed += (nr_free_pool - shrink_pages) << pool->order;
418 if (freed >= sc->nr_to_scan)
419 break;
420 shrink_pages <<= pool->order;
421 }
422 mutex_unlock(&lock);
423 return freed;
424 }
425
426
427 static unsigned long
ttm_pool_shrink_count(struct shrinker * shrink,struct shrink_control * sc)428 ttm_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
429 {
430 unsigned i;
431 unsigned long count = 0;
432 struct ttm_page_pool *pool;
433
434 for (i = 0; i < NUM_POOLS; ++i) {
435 pool = &_manager->pools[i];
436 count += (pool->npages << pool->order);
437 }
438
439 return count;
440 }
441
ttm_pool_mm_shrink_init(struct ttm_pool_manager * manager)442 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
443 {
444 manager->mm_shrink.count_objects = ttm_pool_shrink_count;
445 manager->mm_shrink.scan_objects = ttm_pool_shrink_scan;
446 manager->mm_shrink.seeks = 1;
447 manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
448 ttm_pool_shrink_scan, manager, EVENTHANDLER_PRI_ANY);
449 }
450
ttm_pool_mm_shrink_fini(struct ttm_pool_manager * manager)451 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
452 {
453 EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
454 }
455
ttm_set_pages_caching(struct page ** pages,enum ttm_caching_state cstate,unsigned cpages)456 static int ttm_set_pages_caching(struct page **pages,
457 enum ttm_caching_state cstate, unsigned cpages)
458 {
459 int r = 0;
460 /* Set page caching */
461 switch (cstate) {
462 case tt_uncached:
463 r = ttm_set_pages_array_uc(pages, cpages);
464 if (r)
465 pr_err("Failed to set %d pages to uc!\n", cpages);
466 break;
467 case tt_wc:
468 r = ttm_set_pages_array_wc(pages, cpages);
469 if (r)
470 pr_err("Failed to set %d pages to wc!\n", cpages);
471 break;
472 default:
473 break;
474 }
475 return r;
476 }
477
478 /**
479 * Free pages the pages that failed to change the caching state. If there is
480 * any pages that have changed their caching state already put them to the
481 * pool.
482 */
ttm_handle_caching_state_failure(struct pglist * pages,int ttm_flags,enum ttm_caching_state cstate,struct page ** failed_pages,unsigned cpages)483 static void ttm_handle_caching_state_failure(struct pglist *pages,
484 int ttm_flags, enum ttm_caching_state cstate,
485 struct page **failed_pages, unsigned cpages)
486 {
487 unsigned i;
488 /* Failed pages have to be freed */
489 for (i = 0; i < cpages; ++i) {
490 TAILQ_REMOVE(pages, (struct vm_page *)failed_pages[i], pageq);
491 __free_page(failed_pages[i]);
492 }
493 }
494
495 /**
496 * Allocate new pages with correct caching.
497 *
498 * This function is reentrant if caller updates count depending on number of
499 * pages returned in pages array.
500 */
ttm_alloc_new_pages(struct pglist * pages,gfp_t gfp_flags,int ttm_flags,enum ttm_caching_state cstate,unsigned count,unsigned order)501 static int ttm_alloc_new_pages(struct pglist *pages, gfp_t gfp_flags,
502 int ttm_flags, enum ttm_caching_state cstate,
503 unsigned count, unsigned order)
504 {
505 struct page **caching_array;
506 struct page *p;
507 int r = 0;
508 unsigned i, j, cpages;
509 unsigned npages = 1 << order;
510 unsigned max_cpages = min(count << order, (unsigned)NUM_PAGES_TO_ALLOC);
511
512 /* allocate array for page caching change */
513 caching_array = kmalloc(max_cpages*sizeof(struct page *), M_DRM, M_WAITOK);
514
515 if (!caching_array) {
516 pr_debug("Unable to allocate table for new pages\n");
517 return -ENOMEM;
518 }
519
520 for (i = 0, cpages = 0; i < count; ++i) {
521 p = alloc_pages(gfp_flags, order);
522
523 if (!p) {
524 pr_debug("Unable to get page %u\n", i);
525
526 /* store already allocated pages in the pool after
527 * setting the caching state */
528 if (cpages) {
529 r = ttm_set_pages_caching(caching_array,
530 cstate, cpages);
531 if (r)
532 ttm_handle_caching_state_failure(pages,
533 ttm_flags, cstate,
534 caching_array, cpages);
535 }
536 r = -ENOMEM;
537 goto out;
538 }
539
540 TAILQ_INSERT_HEAD(pages, (struct vm_page *)p, pageq);
541
542 #ifdef CONFIG_HIGHMEM
543 /* gfp flags of highmem page should never be dma32 so we
544 * we should be fine in such case
545 */
546 if (PageHighMem(p))
547 continue;
548
549 #endif
550 for (j = 0; j < npages; ++j) {
551 caching_array[cpages++] = p++;
552 if (cpages == max_cpages) {
553
554 r = ttm_set_pages_caching(caching_array,
555 cstate, cpages);
556 if (r) {
557 ttm_handle_caching_state_failure(pages,
558 ttm_flags, cstate,
559 caching_array, cpages);
560 goto out;
561 }
562 cpages = 0;
563 }
564 }
565 }
566
567 if (cpages) {
568 r = ttm_set_pages_caching(caching_array, cstate, cpages);
569 if (r)
570 ttm_handle_caching_state_failure(pages,
571 ttm_flags, cstate,
572 caching_array, cpages);
573 }
574 out:
575 kfree(caching_array);
576
577 return r;
578 }
579
580 /**
581 * Fill the given pool if there aren't enough pages and the requested number of
582 * pages is small.
583 */
ttm_page_pool_fill_locked(struct ttm_page_pool * pool,int ttm_flags,enum ttm_caching_state cstate,unsigned count,unsigned long * irq_flags)584 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool, int ttm_flags,
585 enum ttm_caching_state cstate,
586 unsigned count, unsigned long *irq_flags)
587 {
588 vm_page_t p;
589 int r;
590 unsigned cpages = 0;
591 /**
592 * Only allow one pool fill operation at a time.
593 * If pool doesn't have enough pages for the allocation new pages are
594 * allocated from outside of pool.
595 */
596 if (pool->fill_lock)
597 return;
598
599 pool->fill_lock = true;
600
601 /* If allocation request is small and there are not enough
602 * pages in a pool we fill the pool up first. */
603 if (count < _manager->options.small
604 && count > pool->npages) {
605 struct pglist new_pages;
606 unsigned alloc_size = _manager->options.alloc_size;
607
608 /**
609 * Can't change page caching if in irqsave context. We have to
610 * drop the pool->lock.
611 */
612 spin_unlock_irqrestore(&pool->lock, *irq_flags);
613
614 TAILQ_INIT(&new_pages);
615 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
616 cstate, alloc_size, 0);
617 spin_lock_irqsave(&pool->lock, *irq_flags);
618
619 if (!r) {
620 TAILQ_CONCAT(&pool->list, &new_pages, pageq);
621 ++pool->nrefills;
622 pool->npages += alloc_size;
623 } else {
624 pr_debug("Failed to fill pool (%p)\n", pool);
625 /* If we have any pages left put them to the pool. */
626 TAILQ_FOREACH(p, &new_pages, pageq) {
627 ++cpages;
628 }
629 TAILQ_CONCAT(&pool->list, &new_pages, pageq);
630 pool->npages += cpages;
631 }
632
633 }
634 pool->fill_lock = false;
635 }
636
637 /**
638 * Cut 'count' number of pages from the pool and put them on the return list.
639 *
640 * @return count of pages still required to fulfill the request.
641 */
ttm_page_pool_get_pages(struct ttm_page_pool * pool,struct pglist * pages,int ttm_flags,enum ttm_caching_state cstate,unsigned count,unsigned order)642 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
643 struct pglist *pages,
644 int ttm_flags,
645 enum ttm_caching_state cstate,
646 unsigned count, unsigned order)
647 {
648 unsigned long irq_flags;
649 vm_page_t p;
650 unsigned i;
651
652 spin_lock_irqsave(&pool->lock, irq_flags);
653 if (!order)
654 ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count,
655 &irq_flags);
656
657 if (count >= pool->npages) {
658 /* take all pages from the pool */
659 TAILQ_CONCAT(pages, &pool->list, pageq);
660 count -= pool->npages;
661 pool->npages = 0;
662 goto out;
663 }
664 for (i = 0; i < count; i++) {
665 p = TAILQ_FIRST(&pool->list);
666 TAILQ_REMOVE(&pool->list, p, pageq);
667 TAILQ_INSERT_TAIL(pages, p, pageq);
668 }
669 pool->npages -= count;
670 count = 0;
671 out:
672 spin_unlock_irqrestore(&pool->lock, irq_flags);
673 return count;
674 }
675
676 /* Put all pages in pages list to correct pool to wait for reuse */
ttm_put_pages(struct page ** pages,unsigned npages,int flags,enum ttm_caching_state cstate)677 static void ttm_put_pages(struct page **pages, unsigned npages, int flags,
678 enum ttm_caching_state cstate)
679 {
680 struct ttm_page_pool *pool = ttm_get_pool(flags, false, cstate);
681 unsigned long irq_flags;
682 unsigned i;
683 struct vm_page *page;
684
685 if (pool == NULL) {
686 /* No pool for this memory type so free the pages */
687 for (i = 0; i < npages; i++) {
688 if (pages[i]) {
689 #if 0
690 if (page_count(pages[i]) != 1)
691 pr_err("Erroneous page count. Leaking pages.\n");
692 #endif
693 __free_page(pages[i]);
694 pages[i] = NULL;
695 }
696 }
697 return;
698 }
699
700 spin_lock_irqsave(&pool->lock, irq_flags);
701 for (i = 0; i < npages; i++) {
702 if (pages[i]) {
703 page = (struct vm_page *)pages[i];
704 TAILQ_INSERT_TAIL(&pool->list, page, pageq);
705 pages[i] = NULL;
706 pool->npages++;
707 }
708 }
709 /* Check that we don't go over the pool limit */
710 npages = 0;
711 if (pool->npages > _manager->options.max_size) {
712 npages = pool->npages - _manager->options.max_size;
713 /* free at least NUM_PAGES_TO_ALLOC number of pages
714 * to reduce calls to set_memory_wb */
715 if (npages < NUM_PAGES_TO_ALLOC)
716 npages = NUM_PAGES_TO_ALLOC;
717 }
718 spin_unlock_irqrestore(&pool->lock, irq_flags);
719 if (npages)
720 ttm_page_pool_free(pool, npages, false);
721 }
722
723 /*
724 * On success pages list will hold count number of correctly
725 * cached pages.
726 */
ttm_get_pages(struct page ** pages,unsigned npages,int flags,enum ttm_caching_state cstate)727 static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
728 enum ttm_caching_state cstate)
729 {
730 struct ttm_page_pool *pool = ttm_get_pool(flags, false, cstate);
731 struct pglist plist;
732 struct vm_page *p = NULL;
733 gfp_t gfp_flags = GFP_USER;
734 unsigned count;
735 int r;
736
737 /* set zero flag for page allocation if required */
738 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
739 gfp_flags |= __GFP_ZERO;
740
741 /* No pool for cached pages */
742 if (pool == NULL) {
743 if (flags & TTM_PAGE_FLAG_DMA32)
744 gfp_flags |= GFP_DMA32;
745 else
746 gfp_flags |= GFP_HIGHUSER;
747
748 for (r = 0; r < npages; ++r) {
749 p = (struct vm_page *)alloc_page(gfp_flags);
750 if (!p) {
751
752 pr_err("Unable to allocate page\n");
753 return -ENOMEM;
754 }
755 pages[r] = (struct page *)p;
756 }
757 return 0;
758 }
759
760 /* combine zero flag to pool flags */
761 gfp_flags |= pool->gfp_flags;
762
763 /* First we take pages from the pool */
764 TAILQ_INIT(&plist);
765 npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages, 0);
766 count = 0;
767 TAILQ_FOREACH(p, &plist, pageq) {
768 pages[count++] = (struct page *)p;
769 }
770
771 /* clear the pages coming from the pool if requested */
772 if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
773 TAILQ_FOREACH(p, &plist, pageq) {
774 pmap_zero_page(VM_PAGE_TO_PHYS(p));
775 }
776 }
777
778 /* If pool didn't have enough pages allocate new one. */
779 if (npages > 0) {
780 /* ttm_alloc_new_pages doesn't reference pool so we can run
781 * multiple requests in parallel.
782 **/
783 TAILQ_INIT(&plist);
784 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate, npages, 0);
785 TAILQ_FOREACH(p, &plist, pageq) {
786 pages[count++] = (struct page *)p;
787 }
788 if (r) {
789 /* If there is any pages in the list put them back to
790 * the pool. */
791 pr_err("Failed to allocate extra pages for large request\n");
792 ttm_put_pages(pages, count, flags, cstate);
793 return r;
794 }
795 }
796
797 return 0;
798 }
799
ttm_page_pool_init_locked(struct ttm_page_pool * pool,gfp_t flags,char * name,unsigned int order)800 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, gfp_t flags,
801 char *name, unsigned int order)
802 {
803 lockinit(&pool->lock, "ttmpool", 0, LK_CANRECURSE);
804 pool->fill_lock = false;
805 TAILQ_INIT(&pool->list);
806 pool->npages = pool->nfrees = 0;
807 pool->gfp_flags = flags;
808 pool->name = name;
809 pool->order = order;
810 }
811
ttm_page_alloc_init(struct ttm_mem_global * glob,unsigned max_pages)812 int 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 if (!_manager)
822 return -ENOMEM;
823
824 ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc", 0);
825
826 ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc", 0);
827
828 ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
829 GFP_USER | GFP_DMA32, "wc dma", 0);
830
831 ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
832 GFP_USER | GFP_DMA32, "uc dma", 0);
833
834 _manager->options.max_size = max_pages;
835 _manager->options.small = SMALL_ALLOCATION;
836 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
837
838 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
839 &glob->kobj, "pool");
840 if (unlikely(ret != 0))
841 goto error;
842
843 ttm_pool_mm_shrink_init(_manager);
844
845 return 0;
846
847 error:
848 kobject_put(&_manager->kobj);
849 _manager = NULL;
850 return ret;
851 }
852
ttm_page_alloc_fini(void)853 void ttm_page_alloc_fini(void)
854 {
855 int i;
856
857 pr_info("Finalizing pool allocator\n");
858 ttm_pool_mm_shrink_fini(_manager);
859
860 /* OK to use static buffer since global mutex is no longer used. */
861 for (i = 0; i < NUM_POOLS; ++i)
862 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES, true);
863
864 kobject_put(&_manager->kobj);
865 _manager = NULL;
866 }
867
868 static void
ttm_pool_unpopulate_helper(struct ttm_tt * ttm,unsigned mem_count_update)869 ttm_pool_unpopulate_helper(struct ttm_tt *ttm, unsigned mem_count_update)
870 {
871 struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
872 unsigned i;
873
874 if (mem_count_update == 0)
875 goto put_pages;
876
877 for (i = 0; i < mem_count_update; ++i) {
878 if (!ttm->pages[i])
879 continue;
880
881 ttm_mem_global_free_page(mem_glob, ttm->pages[i], PAGE_SIZE);
882 }
883
884 put_pages:
885 ttm_put_pages(ttm->pages, ttm->num_pages, ttm->page_flags,
886 ttm->caching_state);
887 ttm->state = tt_unpopulated;
888 }
889
ttm_pool_populate(struct ttm_tt * ttm,struct ttm_operation_ctx * ctx)890 int ttm_pool_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
891 {
892 struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
893 unsigned i;
894 int ret;
895
896 if (ttm->state != tt_unpopulated)
897 return 0;
898
899 if (ttm_check_under_lowerlimit(mem_glob, ttm->num_pages, ctx))
900 return -ENOMEM;
901
902 ret = ttm_get_pages(ttm->pages, ttm->num_pages, ttm->page_flags,
903 ttm->caching_state);
904 if (unlikely(ret != 0)) {
905 ttm_pool_unpopulate_helper(ttm, 0);
906 return ret;
907 }
908
909 for (i = 0; i < ttm->num_pages; ++i) {
910 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
911 PAGE_SIZE, ctx);
912 if (unlikely(ret != 0)) {
913 ttm_pool_unpopulate_helper(ttm, i);
914 return -ENOMEM;
915 }
916 }
917
918 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
919 ret = ttm_tt_swapin(ttm);
920 if (unlikely(ret != 0)) {
921 ttm_pool_unpopulate(ttm);
922 return ret;
923 }
924 }
925
926 ttm->state = tt_unbound;
927 return 0;
928 }
929 EXPORT_SYMBOL(ttm_pool_populate);
930
ttm_pool_unpopulate(struct ttm_tt * ttm)931 void ttm_pool_unpopulate(struct ttm_tt *ttm)
932 {
933 ttm_pool_unpopulate_helper(ttm, ttm->num_pages);
934 }
935 EXPORT_SYMBOL(ttm_pool_unpopulate);
936
ttm_populate_and_map_pages(struct device * dev,struct ttm_dma_tt * tt,struct ttm_operation_ctx * ctx)937 int ttm_populate_and_map_pages(struct device *dev, struct ttm_dma_tt *tt,
938 struct ttm_operation_ctx *ctx)
939 {
940 unsigned i, j;
941 int r;
942
943 r = ttm_pool_populate(&tt->ttm, ctx);
944 if (r)
945 return r;
946
947 for (i = 0; i < tt->ttm.num_pages; ++i) {
948 struct page *p = tt->ttm.pages[i];
949 size_t num_pages = 1;
950
951 for (j = i + 1; j < tt->ttm.num_pages; ++j) {
952 if (++p != tt->ttm.pages[j])
953 break;
954
955 ++num_pages;
956 }
957
958 tt->dma_address[i] = dma_map_page(dev, tt->ttm.pages[i],
959 0, num_pages * PAGE_SIZE,
960 DMA_BIDIRECTIONAL);
961 if (dma_mapping_error(dev, tt->dma_address[i])) {
962 while (i--) {
963 dma_unmap_page(dev, tt->dma_address[i],
964 PAGE_SIZE, DMA_BIDIRECTIONAL);
965 tt->dma_address[i] = 0;
966 }
967 ttm_pool_unpopulate(&tt->ttm);
968 return -EFAULT;
969 }
970
971 for (j = 1; j < num_pages; ++j) {
972 tt->dma_address[i + 1] = tt->dma_address[i] + PAGE_SIZE;
973 ++i;
974 }
975 }
976 return 0;
977 }
978 EXPORT_SYMBOL(ttm_populate_and_map_pages);
979
ttm_unmap_and_unpopulate_pages(struct device * dev,struct ttm_dma_tt * tt)980 void ttm_unmap_and_unpopulate_pages(struct device *dev, struct ttm_dma_tt *tt)
981 {
982 unsigned i, j;
983
984 for (i = 0; i < tt->ttm.num_pages;) {
985 struct page *p = tt->ttm.pages[i];
986 size_t num_pages = 1;
987
988 if (!tt->dma_address[i] || !tt->ttm.pages[i]) {
989 ++i;
990 continue;
991 }
992
993 for (j = i + 1; j < tt->ttm.num_pages; ++j) {
994 if (++p != tt->ttm.pages[j])
995 break;
996
997 ++num_pages;
998 }
999
1000 dma_unmap_page(dev, tt->dma_address[i], num_pages * PAGE_SIZE,
1001 DMA_BIDIRECTIONAL);
1002
1003 i += num_pages;
1004 }
1005 ttm_pool_unpopulate(&tt->ttm);
1006 }
1007 EXPORT_SYMBOL(ttm_unmap_and_unpopulate_pages);
1008
1009 #if 0
1010 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
1011 {
1012 struct ttm_page_pool *p;
1013 unsigned i;
1014 char *h[] = {"pool", "refills", "pages freed", "size"};
1015 if (!_manager) {
1016 seq_printf(m, "No pool allocator running.\n");
1017 return 0;
1018 }
1019 seq_printf(m, "%7s %12s %13s %8s\n",
1020 h[0], h[1], h[2], h[3]);
1021 for (i = 0; i < NUM_POOLS; ++i) {
1022 p = &_manager->pools[i];
1023
1024 seq_printf(m, "%7s %12ld %13ld %8d\n",
1025 p->name, p->nrefills,
1026 p->nfrees, p->npages);
1027 }
1028 return 0;
1029 }
1030 #endif
1031 EXPORT_SYMBOL(ttm_page_alloc_debugfs);
1032