ttm: Introduce a placeholder for DMA (bus) addresses.
[linux-2.6.git] / drivers / gpu / drm / ttm / ttm_page_alloc.c
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 <asm/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  */
69 struct 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
86 struct 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  **/
107 struct 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
123 static struct attribute ttm_page_pool_max = {
124         .name = "pool_max_size",
125         .mode = S_IRUGO | S_IWUSR
126 };
127 static struct attribute ttm_page_pool_small = {
128         .name = "pool_small_allocation",
129         .mode = S_IRUGO | S_IWUSR
130 };
131 static struct attribute ttm_page_pool_alloc_size = {
132         .name = "pool_allocation_size",
133         .mode = S_IRUGO | S_IWUSR
134 };
135
136 static 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
143 static 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
150 static 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
189 static 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
208 static const struct sysfs_ops ttm_pool_sysfs_ops = {
209         .show = &ttm_pool_show,
210         .store = &ttm_pool_store,
211 };
212
213 static 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
219 static struct ttm_pool_manager *_manager;
220
221 #ifndef CONFIG_X86
222 static 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
233 static 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
244 static 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. */
258 static 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. */
278 static 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
288 static 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  **/
304 static 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
323 restart:
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 tough 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);
379 out:
380         kfree(pages_to_free);
381         return nr_free;
382 }
383
384 /* Get good estimation how many pages are free in pools */
385 static 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  */
398 static int ttm_pool_mm_shrink(struct shrinker *shrink, int shrink_pages, gfp_t gfp_mask)
399 {
400         static atomic_t start_pool = ATOMIC_INIT(0);
401         unsigned i;
402         unsigned pool_offset = atomic_add_return(1, &start_pool);
403         struct ttm_page_pool *pool;
404
405         pool_offset = pool_offset % NUM_POOLS;
406         /* select start pool in round robin fashion */
407         for (i = 0; i < NUM_POOLS; ++i) {
408                 unsigned nr_free = shrink_pages;
409                 if (shrink_pages == 0)
410                         break;
411                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
412                 shrink_pages = ttm_page_pool_free(pool, nr_free);
413         }
414         /* return estimated number of unused pages in pool */
415         return ttm_pool_get_num_unused_pages();
416 }
417
418 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
419 {
420         manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
421         manager->mm_shrink.seeks = 1;
422         register_shrinker(&manager->mm_shrink);
423 }
424
425 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
426 {
427         unregister_shrinker(&manager->mm_shrink);
428 }
429
430 static int ttm_set_pages_caching(struct page **pages,
431                 enum ttm_caching_state cstate, unsigned cpages)
432 {
433         int r = 0;
434         /* Set page caching */
435         switch (cstate) {
436         case tt_uncached:
437                 r = set_pages_array_uc(pages, cpages);
438                 if (r)
439                         printk(KERN_ERR TTM_PFX
440                                "Failed to set %d pages to uc!\n",
441                                cpages);
442                 break;
443         case tt_wc:
444                 r = set_pages_array_wc(pages, cpages);
445                 if (r)
446                         printk(KERN_ERR TTM_PFX
447                                "Failed to set %d pages to wc!\n",
448                                cpages);
449                 break;
450         default:
451                 break;
452         }
453         return r;
454 }
455
456 /**
457  * Free pages the pages that failed to change the caching state. If there is
458  * any pages that have changed their caching state already put them to the
459  * pool.
460  */
461 static void ttm_handle_caching_state_failure(struct list_head *pages,
462                 int ttm_flags, enum ttm_caching_state cstate,
463                 struct page **failed_pages, unsigned cpages)
464 {
465         unsigned i;
466         /* Failed pages have to be freed */
467         for (i = 0; i < cpages; ++i) {
468                 list_del(&failed_pages[i]->lru);
469                 __free_page(failed_pages[i]);
470         }
471 }
472
473 /**
474  * Allocate new pages with correct caching.
475  *
476  * This function is reentrant if caller updates count depending on number of
477  * pages returned in pages array.
478  */
479 static int ttm_alloc_new_pages(struct list_head *pages, gfp_t gfp_flags,
480                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
481 {
482         struct page **caching_array;
483         struct page *p;
484         int r = 0;
485         unsigned i, cpages;
486         unsigned max_cpages = min(count,
487                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
488
489         /* allocate array for page caching change */
490         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
491
492         if (!caching_array) {
493                 printk(KERN_ERR TTM_PFX
494                        "Unable to allocate table for new pages.");
495                 return -ENOMEM;
496         }
497
498         for (i = 0, cpages = 0; i < count; ++i) {
499                 p = alloc_page(gfp_flags);
500
501                 if (!p) {
502                         printk(KERN_ERR TTM_PFX "Unable to get page %u.\n", i);
503
504                         /* store already allocated pages in the pool after
505                          * setting the caching state */
506                         if (cpages) {
507                                 r = ttm_set_pages_caching(caching_array,
508                                                           cstate, cpages);
509                                 if (r)
510                                         ttm_handle_caching_state_failure(pages,
511                                                 ttm_flags, cstate,
512                                                 caching_array, cpages);
513                         }
514                         r = -ENOMEM;
515                         goto out;
516                 }
517
518 #ifdef CONFIG_HIGHMEM
519                 /* gfp flags of highmem page should never be dma32 so we
520                  * we should be fine in such case
521                  */
522                 if (!PageHighMem(p))
523 #endif
524                 {
525                         caching_array[cpages++] = p;
526                         if (cpages == max_cpages) {
527
528                                 r = ttm_set_pages_caching(caching_array,
529                                                 cstate, cpages);
530                                 if (r) {
531                                         ttm_handle_caching_state_failure(pages,
532                                                 ttm_flags, cstate,
533                                                 caching_array, cpages);
534                                         goto out;
535                                 }
536                                 cpages = 0;
537                         }
538                 }
539
540                 list_add(&p->lru, pages);
541         }
542
543         if (cpages) {
544                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
545                 if (r)
546                         ttm_handle_caching_state_failure(pages,
547                                         ttm_flags, cstate,
548                                         caching_array, cpages);
549         }
550 out:
551         kfree(caching_array);
552
553         return r;
554 }
555
556 /**
557  * Fill the given pool if there isn't enough pages and requested number of
558  * pages is small.
559  */
560 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
561                 int ttm_flags, enum ttm_caching_state cstate, unsigned count,
562                 unsigned long *irq_flags)
563 {
564         struct page *p;
565         int r;
566         unsigned cpages = 0;
567         /**
568          * Only allow one pool fill operation at a time.
569          * If pool doesn't have enough pages for the allocation new pages are
570          * allocated from outside of pool.
571          */
572         if (pool->fill_lock)
573                 return;
574
575         pool->fill_lock = true;
576
577         /* If allocation request is small and there is not enough
578          * pages in pool we fill the pool first */
579         if (count < _manager->options.small
580                 && count > pool->npages) {
581                 struct list_head new_pages;
582                 unsigned alloc_size = _manager->options.alloc_size;
583
584                 /**
585                  * Can't change page caching if in irqsave context. We have to
586                  * drop the pool->lock.
587                  */
588                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
589
590                 INIT_LIST_HEAD(&new_pages);
591                 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
592                                 cstate, alloc_size);
593                 spin_lock_irqsave(&pool->lock, *irq_flags);
594
595                 if (!r) {
596                         list_splice(&new_pages, &pool->list);
597                         ++pool->nrefills;
598                         pool->npages += alloc_size;
599                 } else {
600                         printk(KERN_ERR TTM_PFX
601                                "Failed to fill pool (%p).", pool);
602                         /* If we have any pages left put them to the pool. */
603                         list_for_each_entry(p, &pool->list, lru) {
604                                 ++cpages;
605                         }
606                         list_splice(&new_pages, &pool->list);
607                         pool->npages += cpages;
608                 }
609
610         }
611         pool->fill_lock = false;
612 }
613
614 /**
615  * Cut count nubmer of pages from the pool and put them to return list
616  *
617  * @return count of pages still to allocate to fill the request.
618  */
619 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
620                 struct list_head *pages, int ttm_flags,
621                 enum ttm_caching_state cstate, unsigned count)
622 {
623         unsigned long irq_flags;
624         struct list_head *p;
625         unsigned i;
626
627         spin_lock_irqsave(&pool->lock, irq_flags);
628         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags);
629
630         if (count >= pool->npages) {
631                 /* take all pages from the pool */
632                 list_splice_init(&pool->list, pages);
633                 count -= pool->npages;
634                 pool->npages = 0;
635                 goto out;
636         }
637         /* find the last pages to include for requested number of pages. Split
638          * pool to begin and halves to reduce search space. */
639         if (count <= pool->npages/2) {
640                 i = 0;
641                 list_for_each(p, &pool->list) {
642                         if (++i == count)
643                                 break;
644                 }
645         } else {
646                 i = pool->npages + 1;
647                 list_for_each_prev(p, &pool->list) {
648                         if (--i == count)
649                                 break;
650                 }
651         }
652         /* Cut count number of pages from pool */
653         list_cut_position(pages, &pool->list, p);
654         pool->npages -= count;
655         count = 0;
656 out:
657         spin_unlock_irqrestore(&pool->lock, irq_flags);
658         return count;
659 }
660
661 /*
662  * On success pages list will hold count number of correctly
663  * cached pages.
664  */
665 int ttm_get_pages(struct list_head *pages, int flags,
666                   enum ttm_caching_state cstate, unsigned count,
667                   dma_addr_t *dma_address)
668 {
669         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
670         struct page *p = NULL;
671         gfp_t gfp_flags = GFP_USER;
672         int r;
673
674         /* set zero flag for page allocation if required */
675         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
676                 gfp_flags |= __GFP_ZERO;
677
678         /* No pool for cached pages */
679         if (pool == NULL) {
680                 if (flags & TTM_PAGE_FLAG_DMA32)
681                         gfp_flags |= GFP_DMA32;
682                 else
683                         gfp_flags |= GFP_HIGHUSER;
684
685                 for (r = 0; r < count; ++r) {
686                         p = alloc_page(gfp_flags);
687                         if (!p) {
688
689                                 printk(KERN_ERR TTM_PFX
690                                        "Unable to allocate page.");
691                                 return -ENOMEM;
692                         }
693
694                         list_add(&p->lru, pages);
695                 }
696                 return 0;
697         }
698
699
700         /* combine zero flag to pool flags */
701         gfp_flags |= pool->gfp_flags;
702
703         /* First we take pages from the pool */
704         count = ttm_page_pool_get_pages(pool, pages, flags, cstate, count);
705
706         /* clear the pages coming from the pool if requested */
707         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
708                 list_for_each_entry(p, pages, lru) {
709                         clear_page(page_address(p));
710                 }
711         }
712
713         /* If pool didn't have enough pages allocate new one. */
714         if (count > 0) {
715                 /* ttm_alloc_new_pages doesn't reference pool so we can run
716                  * multiple requests in parallel.
717                  **/
718                 r = ttm_alloc_new_pages(pages, gfp_flags, flags, cstate, count);
719                 if (r) {
720                         /* If there is any pages in the list put them back to
721                          * the pool. */
722                         printk(KERN_ERR TTM_PFX
723                                "Failed to allocate extra pages "
724                                "for large request.");
725                         ttm_put_pages(pages, 0, flags, cstate, NULL);
726                         return r;
727                 }
728         }
729
730
731         return 0;
732 }
733
734 /* Put all pages in pages list to correct pool to wait for reuse */
735 void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
736                    enum ttm_caching_state cstate, dma_addr_t *dma_address)
737 {
738         unsigned long irq_flags;
739         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
740         struct page *p, *tmp;
741
742         if (pool == NULL) {
743                 /* No pool for this memory type so free the pages */
744
745                 list_for_each_entry_safe(p, tmp, pages, lru) {
746                         __free_page(p);
747                 }
748                 /* Make the pages list empty */
749                 INIT_LIST_HEAD(pages);
750                 return;
751         }
752         if (page_count == 0) {
753                 list_for_each_entry_safe(p, tmp, pages, lru) {
754                         ++page_count;
755                 }
756         }
757
758         spin_lock_irqsave(&pool->lock, irq_flags);
759         list_splice_init(pages, &pool->list);
760         pool->npages += page_count;
761         /* Check that we don't go over the pool limit */
762         page_count = 0;
763         if (pool->npages > _manager->options.max_size) {
764                 page_count = pool->npages - _manager->options.max_size;
765                 /* free at least NUM_PAGES_TO_ALLOC number of pages
766                  * to reduce calls to set_memory_wb */
767                 if (page_count < NUM_PAGES_TO_ALLOC)
768                         page_count = NUM_PAGES_TO_ALLOC;
769         }
770         spin_unlock_irqrestore(&pool->lock, irq_flags);
771         if (page_count)
772                 ttm_page_pool_free(pool, page_count);
773 }
774
775 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
776                 char *name)
777 {
778         spin_lock_init(&pool->lock);
779         pool->fill_lock = false;
780         INIT_LIST_HEAD(&pool->list);
781         pool->npages = pool->nfrees = 0;
782         pool->gfp_flags = flags;
783         pool->name = name;
784 }
785
786 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
787 {
788         int ret;
789
790         WARN_ON(_manager);
791
792         printk(KERN_INFO TTM_PFX "Initializing pool allocator.\n");
793
794         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
795
796         ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
797
798         ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc");
799
800         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
801                                   GFP_USER | GFP_DMA32, "wc dma");
802
803         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
804                                   GFP_USER | GFP_DMA32, "uc dma");
805
806         _manager->options.max_size = max_pages;
807         _manager->options.small = SMALL_ALLOCATION;
808         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
809
810         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
811                                    &glob->kobj, "pool");
812         if (unlikely(ret != 0)) {
813                 kobject_put(&_manager->kobj);
814                 _manager = NULL;
815                 return ret;
816         }
817
818         ttm_pool_mm_shrink_init(_manager);
819
820         return 0;
821 }
822
823 void ttm_page_alloc_fini(void)
824 {
825         int i;
826
827         printk(KERN_INFO TTM_PFX "Finalizing pool allocator.\n");
828         ttm_pool_mm_shrink_fini(_manager);
829
830         for (i = 0; i < NUM_POOLS; ++i)
831                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
832
833         kobject_put(&_manager->kobj);
834         _manager = NULL;
835 }
836
837 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
838 {
839         struct ttm_page_pool *p;
840         unsigned i;
841         char *h[] = {"pool", "refills", "pages freed", "size"};
842         if (!_manager) {
843                 seq_printf(m, "No pool allocator running.\n");
844                 return 0;
845         }
846         seq_printf(m, "%6s %12s %13s %8s\n",
847                         h[0], h[1], h[2], h[3]);
848         for (i = 0; i < NUM_POOLS; ++i) {
849                 p = &_manager->pools[i];
850
851                 seq_printf(m, "%6s %12ld %13ld %8d\n",
852                                 p->name, p->nrefills,
853                                 p->nfrees, p->npages);
854         }
855         return 0;
856 }
857 EXPORT_SYMBOL(ttm_page_alloc_debugfs);