drivers/gpu/drm/ttm/ttm_page_alloc.c

   1 /*
   2  * Copyright (c) Red Hat Inc.
   3
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the
  12  * next paragraph) shall be included in all copies or substantial portions
  13  * of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors: Dave Airlie <airlied@redhat.com>
  24  *          Jerome Glisse <jglisse@redhat.com>
  25  *          Pauli Nieminen <suokkos@gmail.com>
  26  */
  27
  28 /* simple list based uncached page pool
  29  * - Pool collects resently freed pages for reuse
  30  * - Use page->lru to keep a free list
  31  * - doesn't track currently in use pages
  32  */
  33 #include <linux/list.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/highmem.h>
  36 #include <linux/mm_types.h>
  37 #include <linux/module.h>
  38 #include <linux/mm.h>
  39 #include <linux/seq_file.h> /* for seq_printf */
  40 #include <linux/slab.h>
  41 #include <linux/dma-mapping.h>
  42
  43 #include <asm/atomic.h>
  44
  45 #include "ttm/ttm_bo_driver.h"
  46 #include "ttm/ttm_page_alloc.h"
  47
  48 #ifdef TTM_HAS_AGP
  49 #include <asm/agp.h>
  50 #endif
  51
  52 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(struct page *))
  53 #define SMALL_ALLOCATION                16
  54 #define FREE_ALL_PAGES                  (~0U)
  55 /* times are in msecs */
  56 #define PAGE_FREE_INTERVAL              1000
  57
  58 /**
  59  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  60  *
  61  * @lock: Protects the shared pool from concurrnet access. Must be used with
  62  * irqsave/irqrestore variants because pool allocator maybe called from
  63  * delayed work.
  64  * @fill_lock: Prevent concurrent calls to fill.
  65  * @list: Pool of free uc/wc pages for fast reuse.
  66  * @gfp_flags: Flags to pass for alloc_page.
  67  * @npages: Number of pages in pool.
  68  */
  69 struct ttm_page_pool {
  70         spinlock_t              lock;
  71         bool                    fill_lock;
  72         struct list_head        list;
  73         gfp_t                   gfp_flags;
  74         unsigned                npages;
  75         char                    *name;
  76         unsigned long           nfrees;
  77         unsigned long           nrefills;
  78 };
  79
  80 /**
  81  * Limits for the pool. They are handled without locks because only place where
  82  * they may change is in sysfs store. They won't have immediate effect anyway
  83  * so forcing serialization to access them is pointless.
  84  */
  85
  86 struct ttm_pool_opts {
  87         unsigned        alloc_size;
  88         unsigned        max_size;
  89         unsigned        small;
  90 };
  91
  92 #define NUM_POOLS 4
  93
  94 /**
  95  * struct ttm_pool_manager - Holds memory pools for fst allocation
  96  *
  97  * Manager is read only object for pool code so it doesn't need locking.
  98  *
  99  * @free_interval: minimum number of jiffies between freeing pages from pool.
 100  * @page_alloc_inited: reference counting for pool allocation.
 101  * @work: Work that is used to shrink the pool. Work is only run when there is
 102  * some pages to free.
 103  * @small_allocation: Limit in number of pages what is small allocation.
 104  *
 105  * @pools: All pool objects in use.
 106  **/
 107 struct ttm_pool_manager {
 108         struct kobject          kobj;
 109         struct shrinker         mm_shrink;
 110         struct ttm_pool_opts    options;
 111
 112         union {
 113                 struct ttm_page_pool    pools[NUM_POOLS];
 114                 struct {
 115                         struct ttm_page_pool    wc_pool;
 116                         struct ttm_page_pool    uc_pool;
 117                         struct ttm_page_pool    wc_pool_dma32;
 118                         struct ttm_page_pool    uc_pool_dma32;
 119                 } ;
 120         };
 121 };
 122
 123 static struct attribute ttm_page_pool_max = {
 124         .name = "pool_max_size",
 125         .mode = S_IRUGO | S_IWUSR
 126 };
 127 static struct attribute ttm_page_pool_small = {
 128         .name = "pool_small_allocation",
 129         .mode = S_IRUGO | S_IWUSR
 130 };
 131 static struct attribute ttm_page_pool_alloc_size = {
 132         .name = "pool_allocation_size",
 133         .mode = S_IRUGO | S_IWUSR
 134 };
 135
 136 static struct attribute *ttm_pool_attrs[] = {
 137         &ttm_page_pool_max,
 138         &ttm_page_pool_small,
 139         &ttm_page_pool_alloc_size,
 140         NULL
 141 };
 142
 143 static void ttm_pool_kobj_release(struct kobject *kobj)
 144 {
 145         struct ttm_pool_manager *m =
 146                 container_of(kobj, struct ttm_pool_manager, kobj);
 147         kfree(m);
 148 }
 149
 150 static ssize_t ttm_pool_store(struct kobject *kobj,
 151                 struct attribute *attr, const char *buffer, size_t size)
 152 {
 153         struct ttm_pool_manager *m =
 154                 container_of(kobj, struct ttm_pool_manager, kobj);
 155         int chars;
 156         unsigned val;
 157         chars = sscanf(buffer, "%u", &val);
 158         if (chars == 0)
 159                 return size;
 160
 161         /* Convert kb to number of pages */
 162         val = val / (PAGE_SIZE >> 10);
 163
 164         if (attr == &ttm_page_pool_max)
 165                 m->options.max_size = val;
 166         else if (attr == &ttm_page_pool_small)
 167                 m->options.small = val;
 168         else if (attr == &ttm_page_pool_alloc_size) {
 169                 if (val > NUM_PAGES_TO_ALLOC*8) {
 170                         printk(KERN_ERR TTM_PFX
 171                                "Setting allocation size to %lu "
 172                                "is not allowed. Recommended size is "
 173                                "%lu\n",
 174                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 175                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 176                         return size;
 177                 } else if (val > NUM_PAGES_TO_ALLOC) {
 178                         printk(KERN_WARNING TTM_PFX
 179                                "Setting allocation size to "
 180                                "larger than %lu is not recommended.\n",
 181                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 182                 }
 183                 m->options.alloc_size = val;
 184         }
 185
 186         return size;
 187 }
 188
 189 static ssize_t ttm_pool_show(struct kobject *kobj,
 190                 struct attribute *attr, char *buffer)
 191 {
 192         struct ttm_pool_manager *m =
 193                 container_of(kobj, struct ttm_pool_manager, kobj);
 194         unsigned val = 0;
 195
 196         if (attr == &ttm_page_pool_max)
 197                 val = m->options.max_size;
 198         else if (attr == &ttm_page_pool_small)
 199                 val = m->options.small;
 200         else if (attr == &ttm_page_pool_alloc_size)
 201                 val = m->options.alloc_size;
 202
 203         val = val * (PAGE_SIZE >> 10);
 204
 205         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 206 }
 207
 208 static const struct sysfs_ops ttm_pool_sysfs_ops = {
 209         .show = &ttm_pool_show,
 210         .store = &ttm_pool_store,
 211 };
 212
 213 static struct kobj_type ttm_pool_kobj_type = {
 214         .release = &ttm_pool_kobj_release,
 215         .sysfs_ops = &ttm_pool_sysfs_ops,
 216         .default_attrs = ttm_pool_attrs,
 217 };
 218
 219 static struct ttm_pool_manager *_manager;
 220
 221 #ifndef CONFIG_X86
 222 static int set_pages_array_wb(struct page **pages, int addrinarray)
 223 {
 224 #ifdef TTM_HAS_AGP
 225         int i;
 226
 227         for (i = 0; i < addrinarray; i++)
 228                 unmap_page_from_agp(pages[i]);
 229 #endif
 230         return 0;
 231 }
 232
 233 static int set_pages_array_wc(struct page **pages, int addrinarray)
 234 {
 235 #ifdef TTM_HAS_AGP
 236         int i;
 237
 238         for (i = 0; i < addrinarray; i++)
 239                 map_page_into_agp(pages[i]);
 240 #endif
 241         return 0;
 242 }
 243
 244 static int set_pages_array_uc(struct page **pages, int addrinarray)
 245 {
 246 #ifdef TTM_HAS_AGP
 247         int i;
 248
 249         for (i = 0; i < addrinarray; i++)
 250                 map_page_into_agp(pages[i]);
 251 #endif
 252         return 0;
 253 }
 254 #endif
 255
 256 /**
 257  * Select the right pool or requested caching state and ttm flags. */
 258 static struct ttm_page_pool *ttm_get_pool(int flags,
 259                 enum ttm_caching_state cstate)
 260 {
 261         int pool_index;
 262
 263         if (cstate == tt_cached)
 264                 return NULL;
 265
 266         if (cstate == tt_wc)
 267                 pool_index = 0x0;
 268         else
 269                 pool_index = 0x1;
 270
 271         if (flags & TTM_PAGE_FLAG_DMA32)
 272                 pool_index |= 0x2;
 273
 274         return &_manager->pools[pool_index];
 275 }
 276
 277 /* set memory back to wb and free the pages. */
 278 static void ttm_pages_put(struct page *pages[], unsigned npages)
 279 {
 280         unsigned i;
 281         if (set_pages_array_wb(pages, npages))
 282                 printk(KERN_ERR TTM_PFX "Failed to set %d pages to wb!\n",
 283                                 npages);
 284         for (i = 0; i < npages; ++i)
 285                 __free_page(pages[i]);
 286 }
 287
 288 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 289                 unsigned freed_pages)
 290 {
 291         pool->npages -= freed_pages;
 292         pool->nfrees += freed_pages;
 293 }
 294
 295 /**
 296  * Free pages from pool.
 297  *
 298  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 299  * number of pages in one go.
 300  *
 301  * @pool: to free the pages from
 302  * @free_all: If set to true will free all pages in pool
 303  **/
 304 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 305 {
 306         unsigned long irq_flags;
 307         struct page *p;
 308         struct page **pages_to_free;
 309         unsigned freed_pages = 0,
 310                  npages_to_free = nr_free;
 311
 312         if (NUM_PAGES_TO_ALLOC < nr_free)
 313                 npages_to_free = NUM_PAGES_TO_ALLOC;
 314
 315         pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 316                         GFP_KERNEL);
 317         if (!pages_to_free) {
 318                 printk(KERN_ERR TTM_PFX
 319                        "Failed to allocate memory for pool free operation.\n");
 320                 return 0;
 321         }
 322
 323 restart:
 324         spin_lock_irqsave(&pool->lock, irq_flags);
 325
 326         list_for_each_entry_reverse(p, &pool->list, lru) {
 327                 if (freed_pages >= npages_to_free)
 328                         break;
 329
 330                 pages_to_free[freed_pages++] = p;
 331                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 332                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 333                         /* remove range of pages from the pool */
 334                         __list_del(p->lru.prev, &pool->list);
 335
 336                         ttm_pool_update_free_locked(pool, freed_pages);
 337                         /**
 338                          * Because changing page caching is costly
 339                          * we unlock the pool to prevent stalling.
 340                          */
 341                         spin_unlock_irqrestore(&pool->lock, irq_flags);
 342
 343                         ttm_pages_put(pages_to_free, freed_pages);
 344                         if (likely(nr_free != FREE_ALL_PAGES))
 345                                 nr_free -= freed_pages;
 346
 347                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 348                                 npages_to_free = nr_free;
 349                         else
 350                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 351
 352                         freed_pages = 0;
 353
 354                         /* free all so restart the processing */
 355                         if (nr_free)
 356                                 goto restart;
 357
 358                         /* Not allowed to fall tough or break because
 359                          * following context is inside spinlock while we are
 360                          * outside here.
 361                          */
 362                         goto out;
 363
 364                 }
 365         }
 366
 367         /* remove range of pages from the pool */
 368         if (freed_pages) {
 369                 __list_del(&p->lru, &pool->list);
 370
 371                 ttm_pool_update_free_locked(pool, freed_pages);
 372                 nr_free -= freed_pages;
 373         }
 374
 375         spin_unlock_irqrestore(&pool->lock, irq_flags);
 376
 377         if (freed_pages)
 378                 ttm_pages_put(pages_to_free, freed_pages);
 379 out:
 380         kfree(pages_to_free);
 381         return nr_free;
 382 }
 383
 384 /* Get good estimation how many pages are free in pools */
 385 static int ttm_pool_get_num_unused_pages(void)
 386 {
 387         unsigned i;
 388         int total = 0;
 389         for (i = 0; i < NUM_POOLS; ++i)
 390                 total += _manager->pools[i].npages;
 391
 392         return total;
 393 }
 394
 395 /**
 396  * Callback for mm to request pool to reduce number of page held.
 397  */
 398 static int ttm_pool_mm_shrink(struct shrinker *shrink, int shrink_pages, gfp_t gfp_mask)
 399 {
 400         static atomic_t start_pool = ATOMIC_INIT(0);
 401         unsigned i;
 402         unsigned pool_offset = atomic_add_return(1, &start_pool);
 403         struct ttm_page_pool *pool;
 404
 405         pool_offset = pool_offset % NUM_POOLS;
 406         /* select start pool in round robin fashion */
 407         for (i = 0; i < NUM_POOLS; ++i) {
 408                 unsigned nr_free = shrink_pages;
 409                 if (shrink_pages == 0)
 410                         break;
 411                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 412                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 413         }
 414         /* return estimated number of unused pages in pool */
 415         return ttm_pool_get_num_unused_pages();
 416 }
 417
 418 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 419 {
 420         manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
 421         manager->mm_shrink.seeks = 1;
 422         register_shrinker(&manager->mm_shrink);
 423 }
 424
 425 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 426 {
 427         unregister_shrinker(&manager->mm_shrink);
 428 }
 429
 430 static int ttm_set_pages_caching(struct page **pages,
 431                 enum ttm_caching_state cstate, unsigned cpages)
 432 {
 433         int r = 0;
 434         /* Set page caching */
 435         switch (cstate) {
 436         case tt_uncached:
 437                 r = set_pages_array_uc(pages, cpages);
 438                 if (r)
 439                         printk(KERN_ERR TTM_PFX
 440                                "Failed to set %d pages to uc!\n",
 441                                cpages);
 442                 break;
 443         case tt_wc:
 444                 r = set_pages_array_wc(pages, cpages);
 445                 if (r)
 446                         printk(KERN_ERR TTM_PFX
 447                                "Failed to set %d pages to wc!\n",
 448                                cpages);
 449                 break;
 450         default:
 451                 break;
 452         }
 453         return r;
 454 }
 455
 456 /**
 457  * Free pages the pages that failed to change the caching state. If there is
 458  * any pages that have changed their caching state already put them to the
 459  * pool.
 460  */
 461 static void ttm_handle_caching_state_failure(struct list_head *pages,
 462                 int ttm_flags, enum ttm_caching_state cstate,
 463                 struct page **failed_pages, unsigned cpages)
 464 {
 465         unsigned i;
 466         /* Failed pages have to be freed */
 467         for (i = 0; i < cpages; ++i) {
 468                 list_del(&failed_pages[i]->lru);
 469                 __free_page(failed_pages[i]);
 470         }
 471 }
 472
 473 /**
 474  * Allocate new pages with correct caching.
 475  *
 476  * This function is reentrant if caller updates count depending on number of
 477  * pages returned in pages array.
 478  */
 479 static int ttm_alloc_new_pages(struct list_head *pages, gfp_t gfp_flags,
 480                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 481 {
 482         struct page **caching_array;
 483         struct page *p;
 484         int r = 0;
 485         unsigned i, cpages;
 486         unsigned max_cpages = min(count,
 487                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 488
 489         /* allocate array for page caching change */
 490         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 491
 492         if (!caching_array) {
 493                 printk(KERN_ERR TTM_PFX
 494                        "Unable to allocate table for new pages.");
 495                 return -ENOMEM;
 496         }
 497
 498         for (i = 0, cpages = 0; i < count; ++i) {
 499                 p = alloc_page(gfp_flags);
 500
 501                 if (!p) {
 502                         printk(KERN_ERR TTM_PFX "Unable to get page %u.\n", i);
 503
 504                         /* store already allocated pages in the pool after
 505                          * setting the caching state */
 506                         if (cpages) {
 507                                 r = ttm_set_pages_caching(caching_array,
 508                                                           cstate, cpages);
 509                                 if (r)
 510                                         ttm_handle_caching_state_failure(pages,
 511                                                 ttm_flags, cstate,
 512                                                 caching_array, cpages);
 513                         }
 514                         r = -ENOMEM;
 515                         goto out;
 516                 }
 517
 518 #ifdef CONFIG_HIGHMEM
 519                 /* gfp flags of highmem page should never be dma32 so we
 520                  * we should be fine in such case
 521                  */
 522                 if (!PageHighMem(p))
 523 #endif
 524                 {
 525                         caching_array[cpages++] = p;
 526                         if (cpages == max_cpages) {
 527
 528                                 r = ttm_set_pages_caching(caching_array,
 529                                                 cstate, cpages);
 530                                 if (r) {
 531                                         ttm_handle_caching_state_failure(pages,
 532                                                 ttm_flags, cstate,
 533                                                 caching_array, cpages);
 534                                         goto out;
 535                                 }
 536                                 cpages = 0;
 537                         }
 538                 }
 539
 540                 list_add(&p->lru, pages);
 541         }
 542
 543         if (cpages) {
 544                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 545                 if (r)
 546                         ttm_handle_caching_state_failure(pages,
 547                                         ttm_flags, cstate,
 548                                         caching_array, cpages);
 549         }
 550 out:
 551         kfree(caching_array);
 552
 553         return r;
 554 }
 555
 556 /**
 557  * Fill the given pool if there isn't enough pages and requested number of
 558  * pages is small.
 559  */
 560 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 561                 int ttm_flags, enum ttm_caching_state cstate, unsigned count,
 562                 unsigned long *irq_flags)
 563 {
 564         struct page *p;
 565         int r;
 566         unsigned cpages = 0;
 567         /**
 568          * Only allow one pool fill operation at a time.
 569          * If pool doesn't have enough pages for the allocation new pages are
 570          * allocated from outside of pool.
 571          */
 572         if (pool->fill_lock)
 573                 return;
 574
 575         pool->fill_lock = true;
 576
 577         /* If allocation request is small and there is not enough
 578          * pages in pool we fill the pool first */
 579         if (count < _manager->options.small
 580                 && count > pool->npages) {
 581                 struct list_head new_pages;
 582                 unsigned alloc_size = _manager->options.alloc_size;
 583
 584                 /**
 585                  * Can't change page caching if in irqsave context. We have to
 586                  * drop the pool->lock.
 587                  */
 588                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 589
 590                 INIT_LIST_HEAD(&new_pages);
 591                 r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags,
 592                                 cstate, alloc_size);
 593                 spin_lock_irqsave(&pool->lock, *irq_flags);
 594
 595                 if (!r) {
 596                         list_splice(&new_pages, &pool->list);
 597                         ++pool->nrefills;
 598                         pool->npages += alloc_size;
 599                 } else {
 600                         printk(KERN_ERR TTM_PFX
 601                                "Failed to fill pool (%p).", pool);
 602                         /* If we have any pages left put them to the pool. */
 603                         list_for_each_entry(p, &pool->list, lru) {
 604                                 ++cpages;
 605                         }
 606                         list_splice(&new_pages, &pool->list);
 607                         pool->npages += cpages;
 608                 }
 609
 610         }
 611         pool->fill_lock = false;
 612 }
 613
 614 /**
 615  * Cut count nubmer of pages from the pool and put them to return list
 616  *
 617  * @return count of pages still to allocate to fill the request.
 618  */
 619 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 620                 struct list_head *pages, int ttm_flags,
 621                 enum ttm_caching_state cstate, unsigned count)
 622 {
 623         unsigned long irq_flags;
 624         struct list_head *p;
 625         unsigned i;
 626
 627         spin_lock_irqsave(&pool->lock, irq_flags);
 628         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags);
 629
 630         if (count >= pool->npages) {
 631                 /* take all pages from the pool */
 632                 list_splice_init(&pool->list, pages);
 633                 count -= pool->npages;
 634                 pool->npages = 0;
 635                 goto out;
 636         }
 637         /* find the last pages to include for requested number of pages. Split
 638          * pool to begin and halves to reduce search space. */
 639         if (count <= pool->npages/2) {
 640                 i = 0;
 641                 list_for_each(p, &pool->list) {
 642                         if (++i == count)
 643                                 break;
 644                 }
 645         } else {
 646                 i = pool->npages + 1;
 647                 list_for_each_prev(p, &pool->list) {
 648                         if (--i == count)
 649                                 break;
 650                 }
 651         }
 652         /* Cut count number of pages from pool */
 653         list_cut_position(pages, &pool->list, p);
 654         pool->npages -= count;
 655         count = 0;
 656 out:
 657         spin_unlock_irqrestore(&pool->lock, irq_flags);
 658         return count;
 659 }
 660
 661 /*
 662  * On success pages list will hold count number of correctly
 663  * cached pages.
 664  */
 665 int ttm_get_pages(struct list_head *pages, int flags,
 666                   enum ttm_caching_state cstate, unsigned count,
 667                   dma_addr_t *dma_address)
 668 {
 669         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 670         struct page *p = NULL;
 671         gfp_t gfp_flags = GFP_USER;
 672         int r;
 673
 674         /* set zero flag for page allocation if required */
 675         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 676                 gfp_flags |= __GFP_ZERO;
 677
 678         /* No pool for cached pages */
 679         if (pool == NULL) {
 680                 if (flags & TTM_PAGE_FLAG_DMA32)
 681                         gfp_flags |= GFP_DMA32;
 682                 else
 683                         gfp_flags |= GFP_HIGHUSER;
 684
 685                 for (r = 0; r < count; ++r) {
 686                         if ((flags & TTM_PAGE_FLAG_DMA32) && dma_address) {
 687                                 void *addr;
 688                                 addr = dma_alloc_coherent(NULL, PAGE_SIZE,
 689                                                           &dma_address[r],
 690                                                           gfp_flags);
 691                                 if (addr == NULL)
 692                                         return -ENOMEM;
 693                                 p = virt_to_page(addr);
 694                         } else
 695                                 p = alloc_page(gfp_flags);
 696                         if (!p) {
 697
 698                                 printk(KERN_ERR TTM_PFX
 699                                        "Unable to allocate page.");
 700                                 return -ENOMEM;
 701                         }
 702                         list_add(&p->lru, pages);
 703                 }
 704                 return 0;
 705         }
 706
 707
 708         /* combine zero flag to pool flags */
 709         gfp_flags |= pool->gfp_flags;
 710
 711         /* First we take pages from the pool */
 712         count = ttm_page_pool_get_pages(pool, pages, flags, cstate, count);
 713
 714         /* clear the pages coming from the pool if requested */
 715         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 716                 list_for_each_entry(p, pages, lru) {
 717                         clear_page(page_address(p));
 718                 }
 719         }
 720
 721         /* If pool didn't have enough pages allocate new one. */
 722         if (count > 0) {
 723                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 724                  * multiple requests in parallel.
 725                  **/
 726                 r = ttm_alloc_new_pages(pages, gfp_flags, flags, cstate, count);
 727                 if (r) {
 728                         /* If there is any pages in the list put them back to
 729                          * the pool. */
 730                         printk(KERN_ERR TTM_PFX
 731                                "Failed to allocate extra pages "
 732                                "for large request.");
 733                         ttm_put_pages(pages, 0, flags, cstate, NULL);
 734                         return r;
 735                 }
 736         }
 737
 738
 739         return 0;
 740 }
 741
 742 /* Put all pages in pages list to correct pool to wait for reuse */
 743 void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
 744                    enum ttm_caching_state cstate, dma_addr_t *dma_address)
 745 {
 746         unsigned long irq_flags;
 747         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 748         struct page *p, *tmp;
 749         unsigned r;
 750
 751         if (pool == NULL) {
 752                 /* No pool for this memory type so free the pages */
 753
 754                 r = page_count-1;
 755                 list_for_each_entry_safe(p, tmp, pages, lru) {
 756                         if ((flags & TTM_PAGE_FLAG_DMA32) && dma_address) {
 757                                 void *addr = page_address(p);
 758                                 WARN_ON(!addr || !dma_address[r]);
 759                                 if (addr)
 760                                         dma_free_coherent(NULL, PAGE_SIZE,
 761                                                           addr,
 762                                                           dma_address[r]);
 763                                 dma_address[r] = 0;
 764                         } else
 765                                 __free_page(p);
 766                         r--;
 767                 }
 768                 /* Make the pages list empty */
 769                 INIT_LIST_HEAD(pages);
 770                 return;
 771         }
 772         if (page_count == 0) {
 773                 list_for_each_entry_safe(p, tmp, pages, lru) {
 774                         ++page_count;
 775                 }
 776         }
 777
 778         spin_lock_irqsave(&pool->lock, irq_flags);
 779         list_splice_init(pages, &pool->list);
 780         pool->npages += page_count;
 781         /* Check that we don't go over the pool limit */
 782         page_count = 0;
 783         if (pool->npages > _manager->options.max_size) {
 784                 page_count = pool->npages - _manager->options.max_size;
 785                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 786                  * to reduce calls to set_memory_wb */
 787                 if (page_count < NUM_PAGES_TO_ALLOC)
 788                         page_count = NUM_PAGES_TO_ALLOC;
 789         }
 790         spin_unlock_irqrestore(&pool->lock, irq_flags);
 791         if (page_count)
 792                 ttm_page_pool_free(pool, page_count);
 793 }
 794
 795 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 796                 char *name)
 797 {
 798         spin_lock_init(&pool->lock);
 799         pool->fill_lock = false;
 800         INIT_LIST_HEAD(&pool->list);
 801         pool->npages = pool->nfrees = 0;
 802         pool->gfp_flags = flags;
 803         pool->name = name;
 804 }
 805
 806 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 807 {
 808         int ret;
 809
 810         WARN_ON(_manager);
 811
 812         printk(KERN_INFO TTM_PFX "Initializing pool allocator.\n");
 813
 814         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
 815
 816         ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
 817
 818         ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc");
 819
 820         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 821                                   GFP_USER | GFP_DMA32, "wc dma");
 822
 823         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 824                                   GFP_USER | GFP_DMA32, "uc dma");
 825
 826         _manager->options.max_size = max_pages;
 827         _manager->options.small = SMALL_ALLOCATION;
 828         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 829
 830         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
 831                                    &glob->kobj, "pool");
 832         if (unlikely(ret != 0)) {
 833                 kobject_put(&_manager->kobj);
 834                 _manager = NULL;
 835                 return ret;
 836         }
 837
 838         ttm_pool_mm_shrink_init(_manager);
 839
 840         return 0;
 841 }
 842
 843 void ttm_page_alloc_fini(void)
 844 {
 845         int i;
 846
 847         printk(KERN_INFO TTM_PFX "Finalizing pool allocator.\n");
 848         ttm_pool_mm_shrink_fini(_manager);
 849
 850         for (i = 0; i < NUM_POOLS; ++i)
 851                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 852
 853         kobject_put(&_manager->kobj);
 854         _manager = NULL;
 855 }
 856
 857 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 858 {
 859         struct ttm_page_pool *p;
 860         unsigned i;
 861         char *h[] = {"pool", "refills", "pages freed", "size"};
 862         if (!_manager) {
 863                 seq_printf(m, "No pool allocator running.\n");
 864                 return 0;
 865         }
 866         seq_printf(m, "%6s %12s %13s %8s\n",
 867                         h[0], h[1], h[2], h[3]);
 868         for (i = 0; i < NUM_POOLS; ++i) {
 869                 p = &_manager->pools[i];
 870
 871                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 872                                 p->name, p->nrefills,
 873                                 p->nfrees, p->npages);
 874         }
 875         return 0;
 876 }
 877 EXPORT_SYMBOL(ttm_page_alloc_debugfs);