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 serialiazation 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         atomic_t                page_alloc_inited;
 108         struct ttm_pool_opts    options;
 109
 110         union {
 111                 struct ttm_page_pool    pools[NUM_POOLS];
 112                 struct {
 113                         struct ttm_page_pool    wc_pool;
 114                         struct ttm_page_pool    uc_pool;
 115                         struct ttm_page_pool    wc_pool_dma32;
 116                         struct ttm_page_pool    uc_pool_dma32;
 117                 } ;
 118         };
 119 };
 120
 121 static struct attribute ttm_page_pool_max = {
 122         .name = "pool_max_size",
 123         .mode = S_IRUGO | S_IWUSR
 124 };
 125 static struct attribute ttm_page_pool_small = {
 126         .name = "pool_small_allocation",
 127         .mode = S_IRUGO | S_IWUSR
 128 };
 129 static struct attribute ttm_page_pool_alloc_size = {
 130         .name = "pool_allocation_size",
 131         .mode = S_IRUGO | S_IWUSR
 132 };
 133
 134 static struct attribute *ttm_pool_attrs[] = {
 135         &ttm_page_pool_max,
 136         &ttm_page_pool_small,
 137         &ttm_page_pool_alloc_size,
 138         NULL
 139 };
 140
 141 static void ttm_pool_kobj_release(struct kobject *kobj)
 142 {
 143         struct ttm_pool_manager *m =
 144                 container_of(kobj, struct ttm_pool_manager, kobj);
 145         (void)m;
 146 }
 147
 148 static ssize_t ttm_pool_store(struct kobject *kobj,
 149                 struct attribute *attr, const char *buffer, size_t size)
 150 {
 151         struct ttm_pool_manager *m =
 152                 container_of(kobj, struct ttm_pool_manager, kobj);
 153         int chars;
 154         unsigned val;
 155         chars = sscanf(buffer, "%u", &val);
 156         if (chars == 0)
 157                 return size;
 158
 159         /* Convert kb to number of pages */
 160         val = val / (PAGE_SIZE >> 10);
 161
 162         if (attr == &ttm_page_pool_max)
 163                 m->options.max_size = val;
 164         else if (attr == &ttm_page_pool_small)
 165                 m->options.small = val;
 166         else if (attr == &ttm_page_pool_alloc_size) {
 167                 if (val > NUM_PAGES_TO_ALLOC*8) {
 168                         printk(KERN_ERR "[ttm] Setting allocation size to %lu "
 169                                         "is not allowed. Recomended 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] Setting allocation size to "
 176                                         "larger than %lu is not recomended.\n",
 177                                         NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 178                 }
 179                 m->options.alloc_size = val;
 180         }
 181
 182         return size;
 183 }
 184
 185 static ssize_t ttm_pool_show(struct kobject *kobj,
 186                 struct attribute *attr, char *buffer)
 187 {
 188         struct ttm_pool_manager *m =
 189                 container_of(kobj, struct ttm_pool_manager, kobj);
 190         unsigned val = 0;
 191
 192         if (attr == &ttm_page_pool_max)
 193                 val = m->options.max_size;
 194         else if (attr == &ttm_page_pool_small)
 195                 val = m->options.small;
 196         else if (attr == &ttm_page_pool_alloc_size)
 197                 val = m->options.alloc_size;
 198
 199         val = val * (PAGE_SIZE >> 10);
 200
 201         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 202 }
 203
 204 static const struct sysfs_ops ttm_pool_sysfs_ops = {
 205         .show = &ttm_pool_show,
 206         .store = &ttm_pool_store,
 207 };
 208
 209 static struct kobj_type ttm_pool_kobj_type = {
 210         .release = &ttm_pool_kobj_release,
 211         .sysfs_ops = &ttm_pool_sysfs_ops,
 212         .default_attrs = ttm_pool_attrs,
 213 };
 214
 215 static struct ttm_pool_manager _manager = {
 216         .page_alloc_inited      = ATOMIC_INIT(0)
 217 };
 218
 219 #ifndef CONFIG_X86
 220 static int set_pages_array_wb(struct page **pages, int addrinarray)
 221 {
 222 #ifdef TTM_HAS_AGP
 223         int i;
 224
 225         for (i = 0; i < addrinarray; i++)
 226                 unmap_page_from_agp(pages[i]);
 227 #endif
 228         return 0;
 229 }
 230
 231 static int set_pages_array_wc(struct page **pages, int addrinarray)
 232 {
 233 #ifdef TTM_HAS_AGP
 234         int i;
 235
 236         for (i = 0; i < addrinarray; i++)
 237                 map_page_into_agp(pages[i]);
 238 #endif
 239         return 0;
 240 }
 241
 242 static int set_pages_array_uc(struct page **pages, int addrinarray)
 243 {
 244 #ifdef TTM_HAS_AGP
 245         int i;
 246
 247         for (i = 0; i < addrinarray; i++)
 248                 map_page_into_agp(pages[i]);
 249 #endif
 250         return 0;
 251 }
 252 #endif
 253
 254 /**
 255  * Select the right pool or requested caching state and ttm flags. */
 256 static struct ttm_page_pool *ttm_get_pool(int flags,
 257                 enum ttm_caching_state cstate)
 258 {
 259         int pool_index;
 260
 261         if (cstate == tt_cached)
 262                 return NULL;
 263
 264         if (cstate == tt_wc)
 265                 pool_index = 0x0;
 266         else
 267                 pool_index = 0x1;
 268
 269         if (flags & TTM_PAGE_FLAG_DMA32)
 270                 pool_index |= 0x2;
 271
 272         return &_manager.pools[pool_index];
 273 }
 274
 275 /* set memory back to wb and free the pages. */
 276 static void ttm_pages_put(struct page *pages[], unsigned npages)
 277 {
 278         unsigned i;
 279         if (set_pages_array_wb(pages, npages))
 280                 printk(KERN_ERR "[ttm] Failed to set %d pages to wb!\n",
 281                                 npages);
 282         for (i = 0; i < npages; ++i)
 283                 __free_page(pages[i]);
 284 }
 285
 286 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 287                 unsigned freed_pages)
 288 {
 289         pool->npages -= freed_pages;
 290         pool->nfrees += freed_pages;
 291 }
 292
 293 /**
 294  * Free pages from pool.
 295  *
 296  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 297  * number of pages in one go.
 298  *
 299  * @pool: to free the pages from
 300  * @free_all: If set to true will free all pages in pool
 301  **/
 302 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 303 {
 304         unsigned long irq_flags;
 305         struct page *p;
 306         struct page **pages_to_free;
 307         unsigned freed_pages = 0,
 308                  npages_to_free = nr_free;
 309
 310         if (NUM_PAGES_TO_ALLOC < nr_free)
 311                 npages_to_free = NUM_PAGES_TO_ALLOC;
 312
 313         pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 314                         GFP_KERNEL);
 315         if (!pages_to_free) {
 316                 printk(KERN_ERR "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  * Calback 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] Failed to set %d pages to uc!\n",
 437                                         cpages);
 438                 break;
 439         case tt_wc:
 440                 r = set_pages_array_wc(pages, cpages);
 441                 if (r)
 442                         printk(KERN_ERR "[ttm] Failed to set %d pages to wc!\n",
 443                                         cpages);
 444                 break;
 445         default:
 446                 break;
 447         }
 448         return r;
 449 }
 450
 451 /**
 452  * Free pages the pages that failed to change the caching state. If there is
 453  * any pages that have changed their caching state already put them to the
 454  * pool.
 455  */
 456 static void ttm_handle_caching_state_failure(struct list_head *pages,
 457                 int ttm_flags, enum ttm_caching_state cstate,
 458                 struct page **failed_pages, unsigned cpages)
 459 {
 460         unsigned i;
 461         /* Failed pages has to be reed */
 462         for (i = 0; i < cpages; ++i) {
 463                 list_del(&failed_pages[i]->lru);
 464                 __free_page(failed_pages[i]);
 465         }
 466 }
 467
 468 /**
 469  * Allocate new pages with correct caching.
 470  *
 471  * This function is reentrant if caller updates count depending on number of
 472  * pages returned in pages array.
 473  */
 474 static int ttm_alloc_new_pages(struct list_head *pages, int gfp_flags,
 475                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 476 {
 477         struct page **caching_array;
 478         struct page *p;
 479         int r = 0;
 480         unsigned i, cpages;
 481         unsigned max_cpages = min(count,
 482                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 483
 484         /* allocate array for page caching change */
 485         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 486
 487         if (!caching_array) {
 488                 printk(KERN_ERR "[ttm] unable to allocate table for new pages.");
 489                 return -ENOMEM;
 490         }
 491
 492         for (i = 0, cpages = 0; i < count; ++i) {
 493                 p = alloc_page(gfp_flags);
 494
 495                 if (!p) {
 496                         printk(KERN_ERR "[ttm] unable to get page %u\n", i);
 497
 498                         /* store already allocated pages in the pool after
 499                          * setting the caching state */
 500                         if (cpages) {
 501                                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 502                                 if (r)
 503                                         ttm_handle_caching_state_failure(pages,
 504                                                 ttm_flags, cstate,
 505                                                 caching_array, cpages);
 506                         }
 507                         r = -ENOMEM;
 508                         goto out;
 509                 }
 510
 511 #ifdef CONFIG_HIGHMEM
 512                 /* gfp flags of highmem page should never be dma32 so we
 513                  * we should be fine in such case
 514                  */
 515                 if (!PageHighMem(p))
 516 #endif
 517                 {
 518                         caching_array[cpages++] = p;
 519                         if (cpages == max_cpages) {
 520
 521                                 r = ttm_set_pages_caching(caching_array,
 522                                                 cstate, cpages);
 523                                 if (r) {
 524                                         ttm_handle_caching_state_failure(pages,
 525                                                 ttm_flags, cstate,
 526                                                 caching_array, cpages);
 527                                         goto out;
 528                                 }
 529                                 cpages = 0;
 530                         }
 531                 }
 532
 533                 list_add(&p->lru, pages);
 534         }
 535
 536         if (cpages) {
 537                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 538                 if (r)
 539                         ttm_handle_caching_state_failure(pages,
 540                                         ttm_flags, cstate,
 541                                         caching_array, cpages);
 542         }
 543 out:
 544         kfree(caching_array);
 545
 546         return r;
 547 }
 548
 549 /**
 550  * Fill the given pool if there isn't enough pages and requested number of
 551  * pages is small.
 552  */
 553 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 554                 int ttm_flags, enum ttm_caching_state cstate, unsigned count,
 555                 unsigned long *irq_flags)
 556 {
 557         struct page *p;
 558         int r;
 559         unsigned cpages = 0;
 560         /**
 561          * Only allow one pool fill operation at a time.
 562          * If pool doesn't have enough pages for the allocation new pages are
 563          * allocated from outside of pool.
 564          */
 565         if (pool->fill_lock)
 566                 return;
 567
 568         pool->fill_lock = true;
 569
 570         /* If allocation request is small and there is not enough
 571          * pages in pool we fill the pool first */
 572         if (count < _manager.options.small
 573                 && count > pool->npages) {
 574                 struct list_head new_pages;
 575                 unsigned alloc_size = _manager.options.alloc_size;
 576
 577                 /**
 578                  * Can't change page caching if in irqsave context. We have to
 579                  * drop the pool->lock.
 580                  */
 581                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 582
 583                 INIT_LIST_HEAD(&new_pages);
 584                 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
 585                                 cstate, alloc_size);
 586                 spin_lock_irqsave(&pool->lock, *irq_flags);
 587
 588                 if (!r) {
 589                         list_splice(&new_pages, &pool->list);
 590                         ++pool->nrefills;
 591                         pool->npages += alloc_size;
 592                 } else {
 593                         printk(KERN_ERR "[ttm] Failed to fill pool (%p).", pool);
 594                         /* If we have any pages left put them to the pool. */
 595                         list_for_each_entry(p, &pool->list, lru) {
 596                                 ++cpages;
 597                         }
 598                         list_splice(&new_pages, &pool->list);
 599                         pool->npages += cpages;
 600                 }
 601
 602         }
 603         pool->fill_lock = false;
 604 }
 605
 606 /**
 607  * Cut count nubmer of pages from the pool and put them to return list
 608  *
 609  * @return count of pages still to allocate to fill the request.
 610  */
 611 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 612                 struct list_head *pages, int ttm_flags,
 613                 enum ttm_caching_state cstate, unsigned count)
 614 {
 615         unsigned long irq_flags;
 616         struct list_head *p;
 617         unsigned i;
 618
 619         spin_lock_irqsave(&pool->lock, irq_flags);
 620         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags);
 621
 622         if (count >= pool->npages) {
 623                 /* take all pages from the pool */
 624                 list_splice_init(&pool->list, pages);
 625                 count -= pool->npages;
 626                 pool->npages = 0;
 627                 goto out;
 628         }
 629         /* find the last pages to include for requested number of pages. Split
 630          * pool to begin and halves to reduce search space. */
 631         if (count <= pool->npages/2) {
 632                 i = 0;
 633                 list_for_each(p, &pool->list) {
 634                         if (++i == count)
 635                                 break;
 636                 }
 637         } else {
 638                 i = pool->npages + 1;
 639                 list_for_each_prev(p, &pool->list) {
 640                         if (--i == count)
 641                                 break;
 642                 }
 643         }
 644         /* Cut count number of pages from pool */
 645         list_cut_position(pages, &pool->list, p);
 646         pool->npages -= count;
 647         count = 0;
 648 out:
 649         spin_unlock_irqrestore(&pool->lock, irq_flags);
 650         return count;
 651 }
 652
 653 /*
 654  * On success pages list will hold count number of correctly
 655  * cached pages.
 656  */
 657 int ttm_get_pages(struct list_head *pages, int flags,
 658                 enum ttm_caching_state cstate, unsigned count)
 659 {
 660         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 661         struct page *p = NULL;
 662         int gfp_flags = 0;
 663         int r;
 664
 665         /* set zero flag for page allocation if required */
 666         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 667                 gfp_flags |= __GFP_ZERO;
 668
 669         /* No pool for cached pages */
 670         if (pool == NULL) {
 671                 if (flags & TTM_PAGE_FLAG_DMA32)
 672                         gfp_flags |= GFP_DMA32;
 673                 else
 674                         gfp_flags |= __GFP_HIGHMEM;
 675
 676                 for (r = 0; r < count; ++r) {
 677                         p = alloc_page(gfp_flags);
 678                         if (!p) {
 679
 680                                 printk(KERN_ERR "[ttm] unable to allocate page.");
 681                                 return -ENOMEM;
 682                         }
 683
 684                         list_add(&p->lru, pages);
 685                 }
 686                 return 0;
 687         }
 688
 689
 690         /* combine zero flag to pool flags */
 691         gfp_flags |= pool->gfp_flags;
 692
 693         /* First we take pages from the pool */
 694         count = ttm_page_pool_get_pages(pool, pages, flags, cstate, count);
 695
 696         /* clear the pages coming from the pool if requested */
 697         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 698                 list_for_each_entry(p, pages, lru) {
 699                         clear_page(page_address(p));
 700                 }
 701         }
 702
 703         /* If pool didn't have enough pages allocate new one. */
 704         if (count > 0) {
 705                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 706                  * multiple requests in parallel.
 707                  **/
 708                 r = ttm_alloc_new_pages(pages, gfp_flags, flags, cstate, count);
 709                 if (r) {
 710                         /* If there is any pages in the list put them back to
 711                          * the pool. */
 712                         printk(KERN_ERR "[ttm] Failed to allocate extra pages "
 713                                         "for large request.");
 714                         ttm_put_pages(pages, 0, flags, cstate);
 715                         return r;
 716                 }
 717         }
 718
 719
 720         return 0;
 721 }
 722
 723 /* Put all pages in pages list to correct pool to wait for reuse */
 724 void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
 725                 enum ttm_caching_state cstate)
 726 {
 727         unsigned long irq_flags;
 728         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 729         struct page *p, *tmp;
 730
 731         if (pool == NULL) {
 732                 /* No pool for this memory type so free the pages */
 733
 734                 list_for_each_entry_safe(p, tmp, pages, lru) {
 735                         __free_page(p);
 736                 }
 737                 /* Make the pages list empty */
 738                 INIT_LIST_HEAD(pages);
 739                 return;
 740         }
 741         if (page_count == 0) {
 742                 list_for_each_entry_safe(p, tmp, pages, lru) {
 743                         ++page_count;
 744                 }
 745         }
 746
 747         spin_lock_irqsave(&pool->lock, irq_flags);
 748         list_splice_init(pages, &pool->list);
 749         pool->npages += page_count;
 750         /* Check that we don't go over the pool limit */
 751         page_count = 0;
 752         if (pool->npages > _manager.options.max_size) {
 753                 page_count = pool->npages - _manager.options.max_size;
 754                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 755                  * to reduce calls to set_memory_wb */
 756                 if (page_count < NUM_PAGES_TO_ALLOC)
 757                         page_count = NUM_PAGES_TO_ALLOC;
 758         }
 759         spin_unlock_irqrestore(&pool->lock, irq_flags);
 760         if (page_count)
 761                 ttm_page_pool_free(pool, page_count);
 762 }
 763
 764 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 765                 char *name)
 766 {
 767         spin_lock_init(&pool->lock);
 768         pool->fill_lock = false;
 769         INIT_LIST_HEAD(&pool->list);
 770         pool->npages = pool->nfrees = 0;
 771         pool->gfp_flags = flags;
 772         pool->name = name;
 773 }
 774
 775 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 776 {
 777         int ret;
 778         if (atomic_add_return(1, &_manager.page_alloc_inited) > 1)
 779                 return 0;
 780
 781         printk(KERN_INFO "[ttm] Initializing pool allocator.\n");
 782
 783         ttm_page_pool_init_locked(&_manager.wc_pool, GFP_HIGHUSER, "wc");
 784
 785         ttm_page_pool_init_locked(&_manager.uc_pool, GFP_HIGHUSER, "uc");
 786
 787         ttm_page_pool_init_locked(&_manager.wc_pool_dma32, GFP_USER | GFP_DMA32,
 788                         "wc dma");
 789
 790         ttm_page_pool_init_locked(&_manager.uc_pool_dma32, GFP_USER | GFP_DMA32,
 791                         "uc dma");
 792
 793         _manager.options.max_size = max_pages;
 794         _manager.options.small = SMALL_ALLOCATION;
 795         _manager.options.alloc_size = NUM_PAGES_TO_ALLOC;
 796
 797         kobject_init(&_manager.kobj, &ttm_pool_kobj_type);
 798         ret = kobject_add(&_manager.kobj, &glob->kobj, "pool");
 799         if (unlikely(ret != 0)) {
 800                 kobject_put(&_manager.kobj);
 801                 return ret;
 802         }
 803
 804         ttm_pool_mm_shrink_init(&_manager);
 805
 806         return 0;
 807 }
 808
 809 void ttm_page_alloc_fini()
 810 {
 811         int i;
 812
 813         if (atomic_sub_return(1, &_manager.page_alloc_inited) > 0)
 814                 return;
 815
 816         printk(KERN_INFO "[ttm] Finilizing pool allocator.\n");
 817         ttm_pool_mm_shrink_fini(&_manager);
 818
 819         for (i = 0; i < NUM_POOLS; ++i)
 820                 ttm_page_pool_free(&_manager.pools[i], FREE_ALL_PAGES);
 821
 822         kobject_put(&_manager.kobj);
 823 }
 824
 825 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 826 {
 827         struct ttm_page_pool *p;
 828         unsigned i;
 829         char *h[] = {"pool", "refills", "pages freed", "size"};
 830         if (atomic_read(&_manager.page_alloc_inited) == 0) {
 831                 seq_printf(m, "No pool allocator running.\n");
 832                 return 0;
 833         }
 834         seq_printf(m, "%6s %12s %13s %8s\n",
 835                         h[0], h[1], h[2], h[3]);
 836         for (i = 0; i < NUM_POOLS; ++i) {
 837                 p = &_manager.pools[i];
 838
 839                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 840                                 p->name, p->nrefills,
 841                                 p->nfrees, p->npages);
 842         }
 843         return 0;
 844 }
 845 EXPORT_SYMBOL(ttm_page_alloc_debugfs);