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
  44 #include "ttm/ttm_bo_driver.h"
  45 #include "ttm/ttm_page_alloc.h"
  46
  47 #ifdef TTM_HAS_AGP
  48 #include <asm/agp.h>
  49 #endif
  50
  51 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(struct page *))
  52 #define SMALL_ALLOCATION                16
  53 #define FREE_ALL_PAGES                  (~0U)
  54 /* times are in msecs */
  55 #define PAGE_FREE_INTERVAL              1000
  56
  57 /**
  58  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  59  *
  60  * @lock: Protects the shared pool from concurrnet access. Must be used with
  61  * irqsave/irqrestore variants because pool allocator maybe called from
  62  * delayed work.
  63  * @fill_lock: Prevent concurrent calls to fill.
  64  * @list: Pool of free uc/wc pages for fast reuse.
  65  * @gfp_flags: Flags to pass for alloc_page.
  66  * @npages: Number of pages in pool.
  67  */
  68 struct ttm_page_pool {
  69         spinlock_t              lock;
  70         bool                    fill_lock;
  71         struct list_head        list;
  72         int                     gfp_flags;
  73         unsigned                npages;
  74         char                    *name;
  75         unsigned long           nfrees;
  76         unsigned long           nrefills;
  77 };
  78
  79 /**
  80  * Limits for the pool. They are handled without locks because only place where
  81  * they may change is in sysfs store. They won't have immediate effect anyway
  82  * so forcing serialization to access them is pointless.
  83  */
  84
  85 struct ttm_pool_opts {
  86         unsigned        alloc_size;
  87         unsigned        max_size;
  88         unsigned        small;
  89 };
  90
  91 #define NUM_POOLS 4
  92
  93 /**
  94  * struct ttm_pool_manager - Holds memory pools for fst allocation
  95  *
  96  * Manager is read only object for pool code so it doesn't need locking.
  97  *
  98  * @free_interval: minimum number of jiffies between freeing pages from pool.
  99  * @page_alloc_inited: reference counting for pool allocation.
 100  * @work: Work that is used to shrink the pool. Work is only run when there is
 101  * some pages to free.
 102  * @small_allocation: Limit in number of pages what is small allocation.
 103  *
 104  * @pools: All pool objects in use.
 105  **/
 106 struct ttm_pool_manager {
 107         struct kobject          kobj;
 108         struct shrinker         mm_shrink;
 109         struct ttm_pool_opts    options;
 110
 111         union {
 112                 struct ttm_page_pool    pools[NUM_POOLS];
 113                 struct {
 114                         struct ttm_page_pool    wc_pool;
 115                         struct ttm_page_pool    uc_pool;
 116                         struct ttm_page_pool    wc_pool_dma32;
 117                         struct ttm_page_pool    uc_pool_dma32;
 118                 } ;
 119         };
 120 };
 121
 122 static struct attribute ttm_page_pool_max = {
 123         .name = "pool_max_size",
 124         .mode = S_IRUGO | S_IWUSR
 125 };
 126 static struct attribute ttm_page_pool_small = {
 127         .name = "pool_small_allocation",
 128         .mode = S_IRUGO | S_IWUSR
 129 };
 130 static struct attribute ttm_page_pool_alloc_size = {
 131         .name = "pool_allocation_size",
 132         .mode = S_IRUGO | S_IWUSR
 133 };
 134
 135 static struct attribute *ttm_pool_attrs[] = {
 136         &ttm_page_pool_max,
 137         &ttm_page_pool_small,
 138         &ttm_page_pool_alloc_size,
 139         NULL
 140 };
 141
 142 static void ttm_pool_kobj_release(struct kobject *kobj)
 143 {
 144         struct ttm_pool_manager *m =
 145                 container_of(kobj, struct ttm_pool_manager, kobj);
 146         kfree(m);
 147 }
 148
 149 static ssize_t ttm_pool_store(struct kobject *kobj,
 150                 struct attribute *attr, const char *buffer, size_t size)
 151 {
 152         struct ttm_pool_manager *m =
 153                 container_of(kobj, struct ttm_pool_manager, kobj);
 154         int chars;
 155         unsigned val;
 156         chars = sscanf(buffer, "%u", &val);
 157         if (chars == 0)
 158                 return size;
 159
 160         /* Convert kb to number of pages */
 161         val = val / (PAGE_SIZE >> 10);
 162
 163         if (attr == &ttm_page_pool_max)
 164                 m->options.max_size = val;
 165         else if (attr == &ttm_page_pool_small)
 166                 m->options.small = val;
 167         else if (attr == &ttm_page_pool_alloc_size) {
 168                 if (val > NUM_PAGES_TO_ALLOC*8) {
 169                         printk(KERN_ERR TTM_PFX
 170                                "Setting allocation size to %lu "
 171                                "is not allowed. Recommended size is "
 172                                "%lu\n",
 173                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 174                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 175                         return size;
 176                 } else if (val > NUM_PAGES_TO_ALLOC) {
 177                         printk(KERN_WARNING TTM_PFX
 178                                "Setting allocation size to "
 179                                "larger than %lu is not recommended.\n",
 180                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 181                 }
 182                 m->options.alloc_size = val;
 183         }
 184
 185         return size;
 186 }
 187
 188 static ssize_t ttm_pool_show(struct kobject *kobj,
 189                 struct attribute *attr, char *buffer)
 190 {
 191         struct ttm_pool_manager *m =
 192                 container_of(kobj, struct ttm_pool_manager, kobj);
 193         unsigned val = 0;
 194
 195         if (attr == &ttm_page_pool_max)
 196                 val = m->options.max_size;
 197         else if (attr == &ttm_page_pool_small)
 198                 val = m->options.small;
 199         else if (attr == &ttm_page_pool_alloc_size)
 200                 val = m->options.alloc_size;
 201
 202         val = val * (PAGE_SIZE >> 10);
 203
 204         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 205 }
 206
 207 static const struct sysfs_ops ttm_pool_sysfs_ops = {
 208         .show = &ttm_pool_show,
 209         .store = &ttm_pool_store,
 210 };
 211
 212 static struct kobj_type ttm_pool_kobj_type = {
 213         .release = &ttm_pool_kobj_release,
 214         .sysfs_ops = &ttm_pool_sysfs_ops,
 215         .default_attrs = ttm_pool_attrs,
 216 };
 217
 218 static struct ttm_pool_manager *_manager;
 219
 220 #ifndef CONFIG_X86
 221 static int set_pages_array_wb(struct page **pages, int addrinarray)
 222 {
 223 #ifdef TTM_HAS_AGP
 224         int i;
 225
 226         for (i = 0; i < addrinarray; i++)
 227                 unmap_page_from_agp(pages[i]);
 228 #endif
 229         return 0;
 230 }
 231
 232 static int set_pages_array_wc(struct page **pages, int addrinarray)
 233 {
 234 #ifdef TTM_HAS_AGP
 235         int i;
 236
 237         for (i = 0; i < addrinarray; i++)
 238                 map_page_into_agp(pages[i]);
 239 #endif
 240         return 0;
 241 }
 242
 243 static int set_pages_array_uc(struct page **pages, int addrinarray)
 244 {
 245 #ifdef TTM_HAS_AGP
 246         int i;
 247
 248         for (i = 0; i < addrinarray; i++)
 249                 map_page_into_agp(pages[i]);
 250 #endif
 251         return 0;
 252 }
 253 #endif
 254
 255 /**
 256  * Select the right pool or requested caching state and ttm flags. */
 257 static struct ttm_page_pool *ttm_get_pool(int flags,
 258                 enum ttm_caching_state cstate)
 259 {
 260         int pool_index;
 261
 262         if (cstate == tt_cached)
 263                 return NULL;
 264
 265         if (cstate == tt_wc)
 266                 pool_index = 0x0;
 267         else
 268                 pool_index = 0x1;
 269
 270         if (flags & TTM_PAGE_FLAG_DMA32)
 271                 pool_index |= 0x2;
 272
 273         return &_manager->pools[pool_index];
 274 }
 275
 276 /* set memory back to wb and free the pages. */
 277 static void ttm_pages_put(struct page *pages[], unsigned npages)
 278 {
 279         unsigned i;
 280         if (set_pages_array_wb(pages, npages))
 281                 printk(KERN_ERR TTM_PFX "Failed to set %d pages to wb!\n",
 282                                 npages);
 283         for (i = 0; i < npages; ++i)
 284                 __free_page(pages[i]);
 285 }
 286
 287 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 288                 unsigned freed_pages)
 289 {
 290         pool->npages -= freed_pages;
 291         pool->nfrees += freed_pages;
 292 }
 293
 294 /**
 295  * Free pages from pool.
 296  *
 297  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 298  * number of pages in one go.
 299  *
 300  * @pool: to free the pages from
 301  * @free_all: If set to true will free all pages in pool
 302  **/
 303 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 304 {
 305         unsigned long irq_flags;
 306         struct page *p;
 307         struct page **pages_to_free;
 308         unsigned freed_pages = 0,
 309                  npages_to_free = nr_free;
 310
 311         if (NUM_PAGES_TO_ALLOC < nr_free)
 312                 npages_to_free = NUM_PAGES_TO_ALLOC;
 313
 314         pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 315                         GFP_KERNEL);
 316         if (!pages_to_free) {
 317                 printk(KERN_ERR TTM_PFX
 318                        "Failed to allocate memory for pool free operation.\n");
 319                 return 0;
 320         }
 321
 322 restart:
 323         spin_lock_irqsave(&pool->lock, irq_flags);
 324
 325         list_for_each_entry_reverse(p, &pool->list, lru) {
 326                 if (freed_pages >= npages_to_free)
 327                         break;
 328
 329                 pages_to_free[freed_pages++] = p;
 330                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 331                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 332                         /* remove range of pages from the pool */
 333                         __list_del(p->lru.prev, &pool->list);
 334
 335                         ttm_pool_update_free_locked(pool, freed_pages);
 336                         /**
 337                          * Because changing page caching is costly
 338                          * we unlock the pool to prevent stalling.
 339                          */
 340                         spin_unlock_irqrestore(&pool->lock, irq_flags);
 341
 342                         ttm_pages_put(pages_to_free, freed_pages);
 343                         if (likely(nr_free != FREE_ALL_PAGES))
 344                                 nr_free -= freed_pages;
 345
 346                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 347                                 npages_to_free = nr_free;
 348                         else
 349                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 350
 351                         freed_pages = 0;
 352
 353                         /* free all so restart the processing */
 354                         if (nr_free)
 355                                 goto restart;
 356
 357                         /* Not allowed to fall tough or break because
 358                          * following context is inside spinlock while we are
 359                          * outside here.
 360                          */
 361                         goto out;
 362
 363                 }
 364         }
 365
 366         /* remove range of pages from the pool */
 367         if (freed_pages) {
 368                 __list_del(&p->lru, &pool->list);
 369
 370                 ttm_pool_update_free_locked(pool, freed_pages);
 371                 nr_free -= freed_pages;
 372         }
 373
 374         spin_unlock_irqrestore(&pool->lock, irq_flags);
 375
 376         if (freed_pages)
 377                 ttm_pages_put(pages_to_free, freed_pages);
 378 out:
 379         kfree(pages_to_free);
 380         return nr_free;
 381 }
 382
 383 /* Get good estimation how many pages are free in pools */
 384 static int ttm_pool_get_num_unused_pages(void)
 385 {
 386         unsigned i;
 387         int total = 0;
 388         for (i = 0; i < NUM_POOLS; ++i)
 389                 total += _manager->pools[i].npages;
 390
 391         return total;
 392 }
 393
 394 /**
 395  * Callback for mm to request pool to reduce number of page held.
 396  */
 397 static int ttm_pool_mm_shrink(struct shrinker *shrink, int shrink_pages, gfp_t gfp_mask)
 398 {
 399         static atomic_t start_pool = ATOMIC_INIT(0);
 400         unsigned i;
 401         unsigned pool_offset = atomic_add_return(1, &start_pool);
 402         struct ttm_page_pool *pool;
 403
 404         pool_offset = pool_offset % NUM_POOLS;
 405         /* select start pool in round robin fashion */
 406         for (i = 0; i < NUM_POOLS; ++i) {
 407                 unsigned nr_free = shrink_pages;
 408                 if (shrink_pages == 0)
 409                         break;
 410                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 411                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 412         }
 413         /* return estimated number of unused pages in pool */
 414         return ttm_pool_get_num_unused_pages();
 415 }
 416
 417 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 418 {
 419         manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
 420         manager->mm_shrink.seeks = 1;
 421         register_shrinker(&manager->mm_shrink);
 422 }
 423
 424 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 425 {
 426         unregister_shrinker(&manager->mm_shrink);
 427 }
 428
 429 static int ttm_set_pages_caching(struct page **pages,
 430                 enum ttm_caching_state cstate, unsigned cpages)
 431 {
 432         int r = 0;
 433         /* Set page caching */
 434         switch (cstate) {
 435         case tt_uncached:
 436                 r = set_pages_array_uc(pages, cpages);
 437                 if (r)
 438                         printk(KERN_ERR TTM_PFX
 439                                "Failed to set %d pages to uc!\n",
 440                                cpages);
 441                 break;
 442         case tt_wc:
 443                 r = set_pages_array_wc(pages, cpages);
 444                 if (r)
 445                         printk(KERN_ERR TTM_PFX
 446                                "Failed to set %d pages to wc!\n",
 447                                cpages);
 448                 break;
 449         default:
 450                 break;
 451         }
 452         return r;
 453 }
 454
 455 /**
 456  * Free pages the pages that failed to change the caching state. If there is
 457  * any pages that have changed their caching state already put them to the
 458  * pool.
 459  */
 460 static void ttm_handle_caching_state_failure(struct list_head *pages,
 461                 int ttm_flags, enum ttm_caching_state cstate,
 462                 struct page **failed_pages, unsigned cpages)
 463 {
 464         unsigned i;
 465         /* Failed pages have to be freed */
 466         for (i = 0; i < cpages; ++i) {
 467                 list_del(&failed_pages[i]->lru);
 468                 __free_page(failed_pages[i]);
 469         }
 470 }
 471
 472 /**
 473  * Allocate new pages with correct caching.
 474  *
 475  * This function is reentrant if caller updates count depending on number of
 476  * pages returned in pages array.
 477  */
 478 static int ttm_alloc_new_pages(struct list_head *pages, int gfp_flags,
 479                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 480 {
 481         struct page **caching_array;
 482         struct page *p;
 483         int r = 0;
 484         unsigned i, cpages;
 485         unsigned max_cpages = min(count,
 486                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 487
 488         /* allocate array for page caching change */
 489         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 490
 491         if (!caching_array) {
 492                 printk(KERN_ERR TTM_PFX
 493                        "Unable to allocate table for new pages.");
 494                 return -ENOMEM;
 495         }
 496
 497         for (i = 0, cpages = 0; i < count; ++i) {
 498                 p = alloc_page(gfp_flags);
 499
 500                 if (!p) {
 501                         printk(KERN_ERR TTM_PFX "Unable to get page %u.\n", i);
 502
 503                         /* store already allocated pages in the pool after
 504                          * setting the caching state */
 505                         if (cpages) {
 506                                 r = ttm_set_pages_caching(caching_array,
 507                                                           cstate, cpages);
 508                                 if (r)
 509                                         ttm_handle_caching_state_failure(pages,
 510                                                 ttm_flags, cstate,
 511                                                 caching_array, cpages);
 512                         }
 513                         r = -ENOMEM;
 514                         goto out;
 515                 }
 516
 517 #ifdef CONFIG_HIGHMEM
 518                 /* gfp flags of highmem page should never be dma32 so we
 519                  * we should be fine in such case
 520                  */
 521                 if (!PageHighMem(p))
 522 #endif
 523                 {
 524                         caching_array[cpages++] = p;
 525                         if (cpages == max_cpages) {
 526
 527                                 r = ttm_set_pages_caching(caching_array,
 528                                                 cstate, cpages);
 529                                 if (r) {
 530                                         ttm_handle_caching_state_failure(pages,
 531                                                 ttm_flags, cstate,
 532                                                 caching_array, cpages);
 533                                         goto out;
 534                                 }
 535                                 cpages = 0;
 536                         }
 537                 }
 538
 539                 list_add(&p->lru, pages);
 540         }
 541
 542         if (cpages) {
 543                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 544                 if (r)
 545                         ttm_handle_caching_state_failure(pages,
 546                                         ttm_flags, cstate,
 547                                         caching_array, cpages);
 548         }
 549 out:
 550         kfree(caching_array);
 551
 552         return r;
 553 }
 554
 555 /**
 556  * Fill the given pool if there isn't enough pages and requested number of
 557  * pages is small.
 558  */
 559 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 560                 int ttm_flags, enum ttm_caching_state cstate, unsigned count,
 561                 unsigned long *irq_flags)
 562 {
 563         struct page *p;
 564         int r;
 565         unsigned cpages = 0;
 566         /**
 567          * Only allow one pool fill operation at a time.
 568          * If pool doesn't have enough pages for the allocation new pages are
 569          * allocated from outside of pool.
 570          */
 571         if (pool->fill_lock)
 572                 return;
 573
 574         pool->fill_lock = true;
 575
 576         /* If allocation request is small and there is not enough
 577          * pages in pool we fill the pool first */
 578         if (count < _manager->options.small
 579                 && count > pool->npages) {
 580                 struct list_head new_pages;
 581                 unsigned alloc_size = _manager->options.alloc_size;
 582
 583                 /**
 584                  * Can't change page caching if in irqsave context. We have to
 585                  * drop the pool->lock.
 586                  */
 587                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 588
 589                 INIT_LIST_HEAD(&new_pages);
 590                 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
 591                                 cstate, alloc_size);
 592                 spin_lock_irqsave(&pool->lock, *irq_flags);
 593
 594                 if (!r) {
 595                         list_splice(&new_pages, &pool->list);
 596                         ++pool->nrefills;
 597                         pool->npages += alloc_size;
 598                 } else {
 599                         printk(KERN_ERR TTM_PFX
 600                                "Failed to fill pool (%p).", pool);
 601                         /* If we have any pages left put them to the pool. */
 602                         list_for_each_entry(p, &pool->list, lru) {
 603                                 ++cpages;
 604                         }
 605                         list_splice(&new_pages, &pool->list);
 606                         pool->npages += cpages;
 607                 }
 608
 609         }
 610         pool->fill_lock = false;
 611 }
 612
 613 /**
 614  * Cut count nubmer of pages from the pool and put them to return list
 615  *
 616  * @return count of pages still to allocate to fill the request.
 617  */
 618 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 619                 struct list_head *pages, int ttm_flags,
 620                 enum ttm_caching_state cstate, unsigned count)
 621 {
 622         unsigned long irq_flags;
 623         struct list_head *p;
 624         unsigned i;
 625
 626         spin_lock_irqsave(&pool->lock, irq_flags);
 627         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags);
 628
 629         if (count >= pool->npages) {
 630                 /* take all pages from the pool */
 631                 list_splice_init(&pool->list, pages);
 632                 count -= pool->npages;
 633                 pool->npages = 0;
 634                 goto out;
 635         }
 636         /* find the last pages to include for requested number of pages. Split
 637          * pool to begin and halves to reduce search space. */
 638         if (count <= pool->npages/2) {
 639                 i = 0;
 640                 list_for_each(p, &pool->list) {
 641                         if (++i == count)
 642                                 break;
 643                 }
 644         } else {
 645                 i = pool->npages + 1;
 646                 list_for_each_prev(p, &pool->list) {
 647                         if (--i == count)
 648                                 break;
 649                 }
 650         }
 651         /* Cut count number of pages from pool */
 652         list_cut_position(pages, &pool->list, p);
 653         pool->npages -= count;
 654         count = 0;
 655 out:
 656         spin_unlock_irqrestore(&pool->lock, irq_flags);
 657         return count;
 658 }
 659
 660 /*
 661  * On success pages list will hold count number of correctly
 662  * cached pages.
 663  */
 664 int ttm_get_pages(struct list_head *pages, int flags,
 665                 enum ttm_caching_state cstate, unsigned count)
 666 {
 667         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 668         struct page *p = NULL;
 669         int gfp_flags = GFP_USER;
 670         int r;
 671
 672         /* set zero flag for page allocation if required */
 673         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 674                 gfp_flags |= __GFP_ZERO;
 675
 676         /* No pool for cached pages */
 677         if (pool == NULL) {
 678                 if (flags & TTM_PAGE_FLAG_DMA32)
 679                         gfp_flags |= GFP_DMA32;
 680                 else
 681                         gfp_flags |= GFP_HIGHUSER;
 682
 683                 for (r = 0; r < count; ++r) {
 684                         p = alloc_page(gfp_flags);
 685                         if (!p) {
 686
 687                                 printk(KERN_ERR TTM_PFX
 688                                        "Unable to allocate page.");
 689                                 return -ENOMEM;
 690                         }
 691
 692                         list_add(&p->lru, pages);
 693                 }
 694                 return 0;
 695         }
 696
 697
 698         /* combine zero flag to pool flags */
 699         gfp_flags |= pool->gfp_flags;
 700
 701         /* First we take pages from the pool */
 702         count = ttm_page_pool_get_pages(pool, pages, flags, cstate, count);
 703
 704         /* clear the pages coming from the pool if requested */
 705         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 706                 list_for_each_entry(p, pages, lru) {
 707                         clear_page(page_address(p));
 708                 }
 709         }
 710
 711         /* If pool didn't have enough pages allocate new one. */
 712         if (count > 0) {
 713                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 714                  * multiple requests in parallel.
 715                  **/
 716                 r = ttm_alloc_new_pages(pages, gfp_flags, flags, cstate, count);
 717                 if (r) {
 718                         /* If there is any pages in the list put them back to
 719                          * the pool. */
 720                         printk(KERN_ERR TTM_PFX
 721                                "Failed to allocate extra pages "
 722                                "for large request.");
 723                         ttm_put_pages(pages, 0, flags, cstate);
 724                         return r;
 725                 }
 726         }
 727
 728
 729         return 0;
 730 }
 731
 732 /* Put all pages in pages list to correct pool to wait for reuse */
 733 void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
 734                 enum ttm_caching_state cstate)
 735 {
 736         unsigned long irq_flags;
 737         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 738         struct page *p, *tmp;
 739
 740         if (pool == NULL) {
 741                 /* No pool for this memory type so free the pages */
 742
 743                 list_for_each_entry_safe(p, tmp, pages, lru) {
 744                         __free_page(p);
 745                 }
 746                 /* Make the pages list empty */
 747                 INIT_LIST_HEAD(pages);
 748                 return;
 749         }
 750         if (page_count == 0) {
 751                 list_for_each_entry_safe(p, tmp, pages, lru) {
 752                         ++page_count;
 753                 }
 754         }
 755
 756         spin_lock_irqsave(&pool->lock, irq_flags);
 757         list_splice_init(pages, &pool->list);
 758         pool->npages += page_count;
 759         /* Check that we don't go over the pool limit */
 760         page_count = 0;
 761         if (pool->npages > _manager->options.max_size) {
 762                 page_count = pool->npages - _manager->options.max_size;
 763                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 764                  * to reduce calls to set_memory_wb */
 765                 if (page_count < NUM_PAGES_TO_ALLOC)
 766                         page_count = NUM_PAGES_TO_ALLOC;
 767         }
 768         spin_unlock_irqrestore(&pool->lock, irq_flags);
 769         if (page_count)
 770                 ttm_page_pool_free(pool, page_count);
 771 }
 772
 773 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 774                 char *name)
 775 {
 776         spin_lock_init(&pool->lock);
 777         pool->fill_lock = false;
 778         INIT_LIST_HEAD(&pool->list);
 779         pool->npages = pool->nfrees = 0;
 780         pool->gfp_flags = flags;
 781         pool->name = name;
 782 }
 783
 784 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 785 {
 786         int ret;
 787
 788         WARN_ON(_manager);
 789
 790         printk(KERN_INFO TTM_PFX "Initializing pool allocator.\n");
 791
 792         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
 793
 794         ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
 795
 796         ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc");
 797
 798         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 799                                   GFP_USER | GFP_DMA32, "wc dma");
 800
 801         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 802                                   GFP_USER | GFP_DMA32, "uc dma");
 803
 804         _manager->options.max_size = max_pages;
 805         _manager->options.small = SMALL_ALLOCATION;
 806         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 807
 808         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
 809                                    &glob->kobj, "pool");
 810         if (unlikely(ret != 0)) {
 811                 kobject_put(&_manager->kobj);
 812                 _manager = NULL;
 813                 return ret;
 814         }
 815
 816         ttm_pool_mm_shrink_init(_manager);
 817
 818         return 0;
 819 }
 820
 821 void ttm_page_alloc_fini()
 822 {
 823         int i;
 824
 825         printk(KERN_INFO TTM_PFX "Finalizing pool allocator.\n");
 826         ttm_pool_mm_shrink_fini(_manager);
 827
 828         for (i = 0; i < NUM_POOLS; ++i)
 829                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 830
 831         kobject_put(&_manager->kobj);
 832         _manager = NULL;
 833 }
 834
 835 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 836 {
 837         struct ttm_page_pool *p;
 838         unsigned i;
 839         char *h[] = {"pool", "refills", "pages freed", "size"};
 840         if (!_manager) {
 841                 seq_printf(m, "No pool allocator running.\n");
 842                 return 0;
 843         }
 844         seq_printf(m, "%6s %12s %13s %8s\n",
 845                         h[0], h[1], h[2], h[3]);
 846         for (i = 0; i < NUM_POOLS; ++i) {
 847                 p = &_manager->pools[i];
 848
 849                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 850                                 p->name, p->nrefills,
 851                                 p->nfrees, p->npages);
 852         }
 853         return 0;
 854 }
 855 EXPORT_SYMBOL(ttm_page_alloc_debugfs);