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
  42 #include <asm/atomic.h>
  43 #include <asm/agp.h>
  44
  45 #include "ttm/ttm_bo_driver.h"
  46 #include "ttm/ttm_page_alloc.h"
  47
  48
  49 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(struct page *))
  50 #define SMALL_ALLOCATION                16
  51 #define FREE_ALL_PAGES                  (~0U)
  52 /* times are in msecs */
  53 #define PAGE_FREE_INTERVAL              1000
  54
  55 /**
  56  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  57  *
  58  * @lock: Protects the shared pool from concurrnet access. Must be used with
  59  * irqsave/irqrestore variants because pool allocator maybe called from
  60  * delayed work.
  61  * @fill_lock: Prevent concurrent calls to fill.
  62  * @list: Pool of free uc/wc pages for fast reuse.
  63  * @gfp_flags: Flags to pass for alloc_page.
  64  * @npages: Number of pages in pool.
  65  */
  66 struct ttm_page_pool {
  67         spinlock_t              lock;
  68         bool                    fill_lock;
  69         struct list_head        list;
  70         int                     gfp_flags;
  71         unsigned                npages;
  72         char                    *name;
  73         unsigned long           nfrees;
  74         unsigned long           nrefills;
  75 };
  76
  77 /**
  78  * Limits for the pool. They are handled without locks because only place where
  79  * they may change is in sysfs store. They won't have immediate effect anyway
  80  * so forcing serialization to access them is pointless.
  81  */
  82
  83 struct ttm_pool_opts {
  84         unsigned        alloc_size;
  85         unsigned        max_size;
  86         unsigned        small;
  87 };
  88
  89 #define NUM_POOLS 4
  90
  91 /**
  92  * struct ttm_pool_manager - Holds memory pools for fst allocation
  93  *
  94  * Manager is read only object for pool code so it doesn't need locking.
  95  *
  96  * @free_interval: minimum number of jiffies between freeing pages from pool.
  97  * @page_alloc_inited: reference counting for pool allocation.
  98  * @work: Work that is used to shrink the pool. Work is only run when there is
  99  * some pages to free.
 100  * @small_allocation: Limit in number of pages what is small allocation.
 101  *
 102  * @pools: All pool objects in use.
 103  **/
 104 struct ttm_pool_manager {
 105         struct kobject          kobj;
 106         struct shrinker         mm_shrink;
 107         struct ttm_pool_opts    options;
 108
 109         union {
 110                 struct ttm_page_pool    pools[NUM_POOLS];
 111                 struct {
 112                         struct ttm_page_pool    wc_pool;
 113                         struct ttm_page_pool    uc_pool;
 114                         struct ttm_page_pool    wc_pool_dma32;
 115                         struct ttm_page_pool    uc_pool_dma32;
 116                 } ;
 117         };
 118 };
 119
 120 static struct attribute ttm_page_pool_max = {
 121         .name = "pool_max_size",
 122         .mode = S_IRUGO | S_IWUSR
 123 };
 124 static struct attribute ttm_page_pool_small = {
 125         .name = "pool_small_allocation",
 126         .mode = S_IRUGO | S_IWUSR
 127 };
 128 static struct attribute ttm_page_pool_alloc_size = {
 129         .name = "pool_allocation_size",
 130         .mode = S_IRUGO | S_IWUSR
 131 };
 132
 133 static struct attribute *ttm_pool_attrs[] = {
 134         &ttm_page_pool_max,
 135         &ttm_page_pool_small,
 136         &ttm_page_pool_alloc_size,
 137         NULL
 138 };
 139
 140 static void ttm_pool_kobj_release(struct kobject *kobj)
 141 {
 142         struct ttm_pool_manager *m =
 143                 container_of(kobj, struct ttm_pool_manager, kobj);
 144         kfree(m);
 145 }
 146
 147 static ssize_t ttm_pool_store(struct kobject *kobj,
 148                 struct attribute *attr, const char *buffer, size_t size)
 149 {
 150         struct ttm_pool_manager *m =
 151                 container_of(kobj, struct ttm_pool_manager, kobj);
 152         int chars;
 153         unsigned val;
 154         chars = sscanf(buffer, "%u", &val);
 155         if (chars == 0)
 156                 return size;
 157
 158         /* Convert kb to number of pages */
 159         val = val / (PAGE_SIZE >> 10);
 160
 161         if (attr == &ttm_page_pool_max)
 162                 m->options.max_size = val;
 163         else if (attr == &ttm_page_pool_small)
 164                 m->options.small = val;
 165         else if (attr == &ttm_page_pool_alloc_size) {
 166                 if (val > NUM_PAGES_TO_ALLOC*8) {
 167                         printk(KERN_ERR TTM_PFX
 168                                "Setting allocation size to %lu "
 169                                "is not allowed. Recommended size is "
 170                                "%lu\n",
 171                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 172                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 173                         return size;
 174                 } else if (val > NUM_PAGES_TO_ALLOC) {
 175                         printk(KERN_WARNING TTM_PFX
 176                                "Setting allocation size to "
 177                                "larger than %lu is not recommended.\n",
 178                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 179                 }
 180                 m->options.alloc_size = val;
 181         }
 182
 183         return size;
 184 }
 185
 186 static ssize_t ttm_pool_show(struct kobject *kobj,
 187                 struct attribute *attr, char *buffer)
 188 {
 189         struct ttm_pool_manager *m =
 190                 container_of(kobj, struct ttm_pool_manager, kobj);
 191         unsigned val = 0;
 192
 193         if (attr == &ttm_page_pool_max)
 194                 val = m->options.max_size;
 195         else if (attr == &ttm_page_pool_small)
 196                 val = m->options.small;
 197         else if (attr == &ttm_page_pool_alloc_size)
 198                 val = m->options.alloc_size;
 199
 200         val = val * (PAGE_SIZE >> 10);
 201
 202         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 203 }
 204
 205 static const struct sysfs_ops ttm_pool_sysfs_ops = {
 206         .show = &ttm_pool_show,
 207         .store = &ttm_pool_store,
 208 };
 209
 210 static struct kobj_type ttm_pool_kobj_type = {
 211         .release = &ttm_pool_kobj_release,
 212         .sysfs_ops = &ttm_pool_sysfs_ops,
 213         .default_attrs = ttm_pool_attrs,
 214 };
 215
 216 static struct ttm_pool_manager *_manager;
 217
 218 #ifndef CONFIG_X86
 219 static int set_pages_array_wb(struct page **pages, int addrinarray)
 220 {
 221 #ifdef TTM_HAS_AGP
 222         int i;
 223
 224         for (i = 0; i < addrinarray; i++)
 225                 unmap_page_from_agp(pages[i]);
 226 #endif
 227         return 0;
 228 }
 229
 230 static int set_pages_array_wc(struct page **pages, int addrinarray)
 231 {
 232 #ifdef TTM_HAS_AGP
 233         int i;
 234
 235         for (i = 0; i < addrinarray; i++)
 236                 map_page_into_agp(pages[i]);
 237 #endif
 238         return 0;
 239 }
 240
 241 static int set_pages_array_uc(struct page **pages, int addrinarray)
 242 {
 243 #ifdef TTM_HAS_AGP
 244         int i;
 245
 246         for (i = 0; i < addrinarray; i++)
 247                 map_page_into_agp(pages[i]);
 248 #endif
 249         return 0;
 250 }
 251 #endif
 252
 253 /**
 254  * Select the right pool or requested caching state and ttm flags. */
 255 static struct ttm_page_pool *ttm_get_pool(int flags,
 256                 enum ttm_caching_state cstate)
 257 {
 258         int pool_index;
 259
 260         if (cstate == tt_cached)
 261                 return NULL;
 262
 263         if (cstate == tt_wc)
 264                 pool_index = 0x0;
 265         else
 266                 pool_index = 0x1;
 267
 268         if (flags & TTM_PAGE_FLAG_DMA32)
 269                 pool_index |= 0x2;
 270
 271         return &_manager->pools[pool_index];
 272 }
 273
 274 /* set memory back to wb and free the pages. */
 275 static void ttm_pages_put(struct page *pages[], unsigned npages)
 276 {
 277         unsigned i;
 278         if (set_pages_array_wb(pages, npages))
 279                 printk(KERN_ERR TTM_PFX "Failed to set %d pages to wb!\n",
 280                                 npages);
 281         for (i = 0; i < npages; ++i)
 282                 __free_page(pages[i]);
 283 }
 284
 285 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 286                 unsigned freed_pages)
 287 {
 288         pool->npages -= freed_pages;
 289         pool->nfrees += freed_pages;
 290 }
 291
 292 /**
 293  * Free pages from pool.
 294  *
 295  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 296  * number of pages in one go.
 297  *
 298  * @pool: to free the pages from
 299  * @free_all: If set to true will free all pages in pool
 300  **/
 301 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 302 {
 303         unsigned long irq_flags;
 304         struct page *p;
 305         struct page **pages_to_free;
 306         unsigned freed_pages = 0,
 307                  npages_to_free = nr_free;
 308
 309         if (NUM_PAGES_TO_ALLOC < nr_free)
 310                 npages_to_free = NUM_PAGES_TO_ALLOC;
 311
 312         pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 313                         GFP_KERNEL);
 314         if (!pages_to_free) {
 315                 printk(KERN_ERR TTM_PFX
 316                        "Failed to allocate memory for pool free operation.\n");
 317                 return 0;
 318         }
 319
 320 restart:
 321         spin_lock_irqsave(&pool->lock, irq_flags);
 322
 323         list_for_each_entry_reverse(p, &pool->list, lru) {
 324                 if (freed_pages >= npages_to_free)
 325                         break;
 326
 327                 pages_to_free[freed_pages++] = p;
 328                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 329                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 330                         /* remove range of pages from the pool */
 331                         __list_del(p->lru.prev, &pool->list);
 332
 333                         ttm_pool_update_free_locked(pool, freed_pages);
 334                         /**
 335                          * Because changing page caching is costly
 336                          * we unlock the pool to prevent stalling.
 337                          */
 338                         spin_unlock_irqrestore(&pool->lock, irq_flags);
 339
 340                         ttm_pages_put(pages_to_free, freed_pages);
 341                         if (likely(nr_free != FREE_ALL_PAGES))
 342                                 nr_free -= freed_pages;
 343
 344                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 345                                 npages_to_free = nr_free;
 346                         else
 347                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 348
 349                         freed_pages = 0;
 350
 351                         /* free all so restart the processing */
 352                         if (nr_free)
 353                                 goto restart;
 354
 355                         /* Not allowed to fall tough or break because
 356                          * following context is inside spinlock while we are
 357                          * outside here.
 358                          */
 359                         goto out;
 360
 361                 }
 362         }
 363
 364         /* remove range of pages from the pool */
 365         if (freed_pages) {
 366                 __list_del(&p->lru, &pool->list);
 367
 368                 ttm_pool_update_free_locked(pool, freed_pages);
 369                 nr_free -= freed_pages;
 370         }
 371
 372         spin_unlock_irqrestore(&pool->lock, irq_flags);
 373
 374         if (freed_pages)
 375                 ttm_pages_put(pages_to_free, freed_pages);
 376 out:
 377         kfree(pages_to_free);
 378         return nr_free;
 379 }
 380
 381 /* Get good estimation how many pages are free in pools */
 382 static int ttm_pool_get_num_unused_pages(void)
 383 {
 384         unsigned i;
 385         int total = 0;
 386         for (i = 0; i < NUM_POOLS; ++i)
 387                 total += _manager->pools[i].npages;
 388
 389         return total;
 390 }
 391
 392 /**
 393  * Callback for mm to request pool to reduce number of page held.
 394  */
 395 static int ttm_pool_mm_shrink(int shrink_pages, gfp_t gfp_mask)
 396 {
 397         static atomic_t start_pool = ATOMIC_INIT(0);
 398         unsigned i;
 399         unsigned pool_offset = atomic_add_return(1, &start_pool);
 400         struct ttm_page_pool *pool;
 401
 402         pool_offset = pool_offset % NUM_POOLS;
 403         /* select start pool in round robin fashion */
 404         for (i = 0; i < NUM_POOLS; ++i) {
 405                 unsigned nr_free = shrink_pages;
 406                 if (shrink_pages == 0)
 407                         break;
 408                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 409                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 410         }
 411         /* return estimated number of unused pages in pool */
 412         return ttm_pool_get_num_unused_pages();
 413 }
 414
 415 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 416 {
 417         manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
 418         manager->mm_shrink.seeks = 1;
 419         register_shrinker(&manager->mm_shrink);
 420 }
 421
 422 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 423 {
 424         unregister_shrinker(&manager->mm_shrink);
 425 }
 426
 427 static int ttm_set_pages_caching(struct page **pages,
 428                 enum ttm_caching_state cstate, unsigned cpages)
 429 {
 430         int r = 0;
 431         /* Set page caching */
 432         switch (cstate) {
 433         case tt_uncached:
 434                 r = set_pages_array_uc(pages, cpages);
 435                 if (r)
 436                         printk(KERN_ERR TTM_PFX
 437                                "Failed to set %d pages to uc!\n",
 438                                cpages);
 439                 break;
 440         case tt_wc:
 441                 r = set_pages_array_wc(pages, cpages);
 442                 if (r)
 443                         printk(KERN_ERR TTM_PFX
 444                                "Failed to set %d pages to wc!\n",
 445                                cpages);
 446                 break;
 447         default:
 448                 break;
 449         }
 450         return r;
 451 }
 452
 453 /**
 454  * Free pages the pages that failed to change the caching state. If there is
 455  * any pages that have changed their caching state already put them to the
 456  * pool.
 457  */
 458 static void ttm_handle_caching_state_failure(struct list_head *pages,
 459                 int ttm_flags, enum ttm_caching_state cstate,
 460                 struct page **failed_pages, unsigned cpages)
 461 {
 462         unsigned i;
 463         /* Failed pages have to be freed */
 464         for (i = 0; i < cpages; ++i) {
 465                 list_del(&failed_pages[i]->lru);
 466                 __free_page(failed_pages[i]);
 467         }
 468 }
 469
 470 /**
 471  * Allocate new pages with correct caching.
 472  *
 473  * This function is reentrant if caller updates count depending on number of
 474  * pages returned in pages array.
 475  */
 476 static int ttm_alloc_new_pages(struct list_head *pages, int gfp_flags,
 477                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 478 {
 479         struct page **caching_array;
 480         struct page *p;
 481         int r = 0;
 482         unsigned i, cpages;
 483         unsigned max_cpages = min(count,
 484                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 485
 486         /* allocate array for page caching change */
 487         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 488
 489         if (!caching_array) {
 490                 printk(KERN_ERR TTM_PFX
 491                        "Unable to allocate table for new pages.");
 492                 return -ENOMEM;
 493         }
 494
 495         for (i = 0, cpages = 0; i < count; ++i) {
 496                 p = alloc_page(gfp_flags);
 497
 498                 if (!p) {
 499                         printk(KERN_ERR TTM_PFX "Unable to get page %u.\n", i);
 500
 501                         /* store already allocated pages in the pool after
 502                          * setting the caching state */
 503                         if (cpages) {
 504                                 r = ttm_set_pages_caching(caching_array,
 505                                                           cstate, cpages);
 506                                 if (r)
 507                                         ttm_handle_caching_state_failure(pages,
 508                                                 ttm_flags, cstate,
 509                                                 caching_array, cpages);
 510                         }
 511                         r = -ENOMEM;
 512                         goto out;
 513                 }
 514
 515 #ifdef CONFIG_HIGHMEM
 516                 /* gfp flags of highmem page should never be dma32 so we
 517                  * we should be fine in such case
 518                  */
 519                 if (!PageHighMem(p))
 520 #endif
 521                 {
 522                         caching_array[cpages++] = p;
 523                         if (cpages == max_cpages) {
 524
 525                                 r = ttm_set_pages_caching(caching_array,
 526                                                 cstate, cpages);
 527                                 if (r) {
 528                                         ttm_handle_caching_state_failure(pages,
 529                                                 ttm_flags, cstate,
 530                                                 caching_array, cpages);
 531                                         goto out;
 532                                 }
 533                                 cpages = 0;
 534                         }
 535                 }
 536
 537                 list_add(&p->lru, pages);
 538         }
 539
 540         if (cpages) {
 541                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 542                 if (r)
 543                         ttm_handle_caching_state_failure(pages,
 544                                         ttm_flags, cstate,
 545                                         caching_array, cpages);
 546         }
 547 out:
 548         kfree(caching_array);
 549
 550         return r;
 551 }
 552
 553 /**
 554  * Fill the given pool if there isn't enough pages and requested number of
 555  * pages is small.
 556  */
 557 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 558                 int ttm_flags, enum ttm_caching_state cstate, unsigned count,
 559                 unsigned long *irq_flags)
 560 {
 561         struct page *p;
 562         int r;
 563         unsigned cpages = 0;
 564         /**
 565          * Only allow one pool fill operation at a time.
 566          * If pool doesn't have enough pages for the allocation new pages are
 567          * allocated from outside of pool.
 568          */
 569         if (pool->fill_lock)
 570                 return;
 571
 572         pool->fill_lock = true;
 573
 574         /* If allocation request is small and there is not enough
 575          * pages in pool we fill the pool first */
 576         if (count < _manager->options.small
 577                 && count > pool->npages) {
 578                 struct list_head new_pages;
 579                 unsigned alloc_size = _manager->options.alloc_size;
 580
 581                 /**
 582                  * Can't change page caching if in irqsave context. We have to
 583                  * drop the pool->lock.
 584                  */
 585                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 586
 587                 INIT_LIST_HEAD(&new_pages);
 588                 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
 589                                 cstate, alloc_size);
 590                 spin_lock_irqsave(&pool->lock, *irq_flags);
 591
 592                 if (!r) {
 593                         list_splice(&new_pages, &pool->list);
 594                         ++pool->nrefills;
 595                         pool->npages += alloc_size;
 596                 } else {
 597                         printk(KERN_ERR TTM_PFX
 598                                "Failed to fill pool (%p).", pool);
 599                         /* If we have any pages left put them to the pool. */
 600                         list_for_each_entry(p, &pool->list, lru) {
 601                                 ++cpages;
 602                         }
 603                         list_splice(&new_pages, &pool->list);
 604                         pool->npages += cpages;
 605                 }
 606
 607         }
 608         pool->fill_lock = false;
 609 }
 610
 611 /**
 612  * Cut count nubmer of pages from the pool and put them to return list
 613  *
 614  * @return count of pages still to allocate to fill the request.
 615  */
 616 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 617                 struct list_head *pages, int ttm_flags,
 618                 enum ttm_caching_state cstate, unsigned count)
 619 {
 620         unsigned long irq_flags;
 621         struct list_head *p;
 622         unsigned i;
 623
 624         spin_lock_irqsave(&pool->lock, irq_flags);
 625         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags);
 626
 627         if (count >= pool->npages) {
 628                 /* take all pages from the pool */
 629                 list_splice_init(&pool->list, pages);
 630                 count -= pool->npages;
 631                 pool->npages = 0;
 632                 goto out;
 633         }
 634         /* find the last pages to include for requested number of pages. Split
 635          * pool to begin and halves to reduce search space. */
 636         if (count <= pool->npages/2) {
 637                 i = 0;
 638                 list_for_each(p, &pool->list) {
 639                         if (++i == count)
 640                                 break;
 641                 }
 642         } else {
 643                 i = pool->npages + 1;
 644                 list_for_each_prev(p, &pool->list) {
 645                         if (--i == count)
 646                                 break;
 647                 }
 648         }
 649         /* Cut count number of pages from pool */
 650         list_cut_position(pages, &pool->list, p);
 651         pool->npages -= count;
 652         count = 0;
 653 out:
 654         spin_unlock_irqrestore(&pool->lock, irq_flags);
 655         return count;
 656 }
 657
 658 /*
 659  * On success pages list will hold count number of correctly
 660  * cached pages.
 661  */
 662 int ttm_get_pages(struct list_head *pages, int flags,
 663                 enum ttm_caching_state cstate, unsigned count)
 664 {
 665         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 666         struct page *p = NULL;
 667         int gfp_flags = GFP_USER;
 668         int r;
 669
 670         /* set zero flag for page allocation if required */
 671         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 672                 gfp_flags |= __GFP_ZERO;
 673
 674         /* No pool for cached pages */
 675         if (pool == NULL) {
 676                 if (flags & TTM_PAGE_FLAG_DMA32)
 677                         gfp_flags |= GFP_DMA32;
 678                 else
 679                         gfp_flags |= GFP_HIGHUSER;
 680
 681                 for (r = 0; r < count; ++r) {
 682                         p = alloc_page(gfp_flags);
 683                         if (!p) {
 684
 685                                 printk(KERN_ERR TTM_PFX
 686                                        "Unable to allocate page.");
 687                                 return -ENOMEM;
 688                         }
 689
 690                         list_add(&p->lru, pages);
 691                 }
 692                 return 0;
 693         }
 694
 695
 696         /* combine zero flag to pool flags */
 697         gfp_flags |= pool->gfp_flags;
 698
 699         /* First we take pages from the pool */
 700         count = ttm_page_pool_get_pages(pool, pages, flags, cstate, count);
 701
 702         /* clear the pages coming from the pool if requested */
 703         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 704                 list_for_each_entry(p, pages, lru) {
 705                         clear_page(page_address(p));
 706                 }
 707         }
 708
 709         /* If pool didn't have enough pages allocate new one. */
 710         if (count > 0) {
 711                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 712                  * multiple requests in parallel.
 713                  **/
 714                 r = ttm_alloc_new_pages(pages, gfp_flags, flags, cstate, count);
 715                 if (r) {
 716                         /* If there is any pages in the list put them back to
 717                          * the pool. */
 718                         printk(KERN_ERR TTM_PFX
 719                                "Failed to allocate extra pages "
 720                                "for large request.");
 721                         ttm_put_pages(pages, 0, flags, cstate);
 722                         return r;
 723                 }
 724         }
 725
 726
 727         return 0;
 728 }
 729
 730 /* Put all pages in pages list to correct pool to wait for reuse */
 731 void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
 732                 enum ttm_caching_state cstate)
 733 {
 734         unsigned long irq_flags;
 735         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 736         struct page *p, *tmp;
 737
 738         if (pool == NULL) {
 739                 /* No pool for this memory type so free the pages */
 740
 741                 list_for_each_entry_safe(p, tmp, pages, lru) {
 742                         __free_page(p);
 743                 }
 744                 /* Make the pages list empty */
 745                 INIT_LIST_HEAD(pages);
 746                 return;
 747         }
 748         if (page_count == 0) {
 749                 list_for_each_entry_safe(p, tmp, pages, lru) {
 750                         ++page_count;
 751                 }
 752         }
 753
 754         spin_lock_irqsave(&pool->lock, irq_flags);
 755         list_splice_init(pages, &pool->list);
 756         pool->npages += page_count;
 757         /* Check that we don't go over the pool limit */
 758         page_count = 0;
 759         if (pool->npages > _manager->options.max_size) {
 760                 page_count = pool->npages - _manager->options.max_size;
 761                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 762                  * to reduce calls to set_memory_wb */
 763                 if (page_count < NUM_PAGES_TO_ALLOC)
 764                         page_count = NUM_PAGES_TO_ALLOC;
 765         }
 766         spin_unlock_irqrestore(&pool->lock, irq_flags);
 767         if (page_count)
 768                 ttm_page_pool_free(pool, page_count);
 769 }
 770
 771 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 772                 char *name)
 773 {
 774         spin_lock_init(&pool->lock);
 775         pool->fill_lock = false;
 776         INIT_LIST_HEAD(&pool->list);
 777         pool->npages = pool->nfrees = 0;
 778         pool->gfp_flags = flags;
 779         pool->name = name;
 780 }
 781
 782 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 783 {
 784         int ret;
 785
 786         WARN_ON(_manager);
 787
 788         printk(KERN_INFO TTM_PFX "Initializing pool allocator.\n");
 789
 790         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
 791
 792         ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
 793
 794         ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc");
 795
 796         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 797                                   GFP_USER | GFP_DMA32, "wc dma");
 798
 799         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 800                                   GFP_USER | GFP_DMA32, "uc dma");
 801
 802         _manager->options.max_size = max_pages;
 803         _manager->options.small = SMALL_ALLOCATION;
 804         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 805
 806         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
 807                                    &glob->kobj, "pool");
 808         if (unlikely(ret != 0)) {
 809                 kobject_put(&_manager->kobj);
 810                 _manager = NULL;
 811                 return ret;
 812         }
 813
 814         ttm_pool_mm_shrink_init(_manager);
 815
 816         return 0;
 817 }
 818
 819 void ttm_page_alloc_fini()
 820 {
 821         int i;
 822
 823         printk(KERN_INFO TTM_PFX "Finalizing pool allocator.\n");
 824         ttm_pool_mm_shrink_fini(_manager);
 825
 826         for (i = 0; i < NUM_POOLS; ++i)
 827                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 828
 829         kobject_put(&_manager->kobj);
 830         _manager = NULL;
 831 }
 832
 833 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 834 {
 835         struct ttm_page_pool *p;
 836         unsigned i;
 837         char *h[] = {"pool", "refills", "pages freed", "size"};
 838         if (!_manager) {
 839                 seq_printf(m, "No pool allocator running.\n");
 840                 return 0;
 841         }
 842         seq_printf(m, "%6s %12s %13s %8s\n",
 843                         h[0], h[1], h[2], h[3]);
 844         for (i = 0; i < NUM_POOLS; ++i) {
 845                 p = &_manager->pools[i];
 846
 847                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 848                                 p->name, p->nrefills,
 849                                 p->nfrees, p->npages);
 850         }
 851         return 0;
 852 }
 853 EXPORT_SYMBOL(ttm_page_alloc_debugfs);