drivers/gpu/drm/ttm/ttm_page_alloc_dma.c

   1 /*
   2  * Copyright 2011 (c) Oracle Corp.
   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  * Author: Konrad Rzeszutek Wilk <[email protected]>
  24  */
  25
  26 /*
  27  * A simple DMA pool losely based on dmapool.c. It has certain advantages
  28  * over the DMA pools:
  29  * - Pool collects resently freed pages for reuse (and hooks up to
  30  *   the shrinker).
  31  * - Tracks currently in use pages
  32  * - Tracks whether the page is UC, WB or cached (and reverts to WB
  33  *   when freed).
  34  */
  35
  36 #if defined(CONFIG_SWIOTLB) || defined(CONFIG_INTEL_IOMMU)
  37 #define pr_fmt(fmt) "[TTM] " fmt
  38
  39 #include <linux/dma-mapping.h>
  40 #include <linux/list.h>
  41 #include <linux/seq_file.h> /* for seq_printf */
  42 #include <linux/slab.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/highmem.h>
  45 #include <linux/mm_types.h>
  46 #include <linux/module.h>
  47 #include <linux/mm.h>
  48 #include <linux/atomic.h>
  49 #include <linux/device.h>
  50 #include <linux/kthread.h>
  51 #include <drm/ttm/ttm_bo_driver.h>
  52 #include <drm/ttm/ttm_page_alloc.h>
  53 #if IS_ENABLED(CONFIG_AGP)
  54 #include <asm/agp.h>
  55 #endif
  56 #ifdef CONFIG_X86
  57 #include <asm/set_memory.h>
  58 #endif
  59
  60 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(struct page *))
  61 #define SMALL_ALLOCATION                4
  62 #define FREE_ALL_PAGES                  (~0U)
  63 #define VADDR_FLAG_HUGE_POOL            1UL
  64 #define VADDR_FLAG_UPDATED_COUNT        2UL
  65
  66 enum pool_type {
  67         IS_UNDEFINED    = 0,
  68         IS_WC           = 1 << 1,
  69         IS_UC           = 1 << 2,
  70         IS_CACHED       = 1 << 3,
  71         IS_DMA32        = 1 << 4,
  72         IS_HUGE         = 1 << 5
  73 };
  74
  75 /*
  76  * The pool structure. There are up to nine pools:
  77  *  - generic (not restricted to DMA32):
  78  *      - write combined, uncached, cached.
  79  *  - dma32 (up to 2^32 - so up 4GB):
  80  *      - write combined, uncached, cached.
  81  *  - huge (not restricted to DMA32):
  82  *      - write combined, uncached, cached.
  83  * for each 'struct device'. The 'cached' is for pages that are actively used.
  84  * The other ones can be shrunk by the shrinker API if neccessary.
  85  * @pools: The 'struct device->dma_pools' link.
  86  * @type: Type of the pool
  87  * @lock: Protects the free_list from concurrnet access. Must be
  88  * used with irqsave/irqrestore variants because pool allocator maybe called
  89  * from delayed work.
  90  * @free_list: Pool of pages that are free to be used. No order requirements.
  91  * @dev: The device that is associated with these pools.
  92  * @size: Size used during DMA allocation.
  93  * @npages_free: Count of available pages for re-use.
  94  * @npages_in_use: Count of pages that are in use.
  95  * @nfrees: Stats when pool is shrinking.
  96  * @nrefills: Stats when the pool is grown.
  97  * @gfp_flags: Flags to pass for alloc_page.
  98  * @name: Name of the pool.
  99  * @dev_name: Name derieved from dev - similar to how dev_info works.
 100  *   Used during shutdown as the dev_info during release is unavailable.
 101  */
 102 struct dma_pool {
 103         struct list_head pools; /* The 'struct device->dma_pools link */
 104         enum pool_type type;
 105         spinlock_t lock;
 106         struct list_head free_list;
 107         struct device *dev;
 108         unsigned size;
 109         unsigned npages_free;
 110         unsigned npages_in_use;
 111         unsigned long nfrees; /* Stats when shrunk. */
 112         unsigned long nrefills; /* Stats when grown. */
 113         gfp_t gfp_flags;
 114         char name[13]; /* "cached dma32" */
 115         char dev_name[64]; /* Constructed from dev */
 116 };
 117
 118 /*
 119  * The accounting page keeping track of the allocated page along with
 120  * the DMA address.
 121  * @page_list: The link to the 'page_list' in 'struct dma_pool'.
 122  * @vaddr: The virtual address of the page and a flag if the page belongs to a
 123  * huge pool
 124  * @dma: The bus address of the page. If the page is not allocated
 125  *   via the DMA API, it will be -1.
 126  */
 127 struct dma_page {
 128         struct list_head page_list;
 129         unsigned long vaddr;
 130         struct page *p;
 131         dma_addr_t dma;
 132 };
 133
 134 /*
 135  * Limits for the pool. They are handled without locks because only place where
 136  * they may change is in sysfs store. They won't have immediate effect anyway
 137  * so forcing serialization to access them is pointless.
 138  */
 139
 140 struct ttm_pool_opts {
 141         unsigned        alloc_size;
 142         unsigned        max_size;
 143         unsigned        small;
 144 };
 145
 146 /*
 147  * Contains the list of all of the 'struct device' and their corresponding
 148  * DMA pools. Guarded by _mutex->lock.
 149  * @pools: The link to 'struct ttm_pool_manager->pools'
 150  * @dev: The 'struct device' associated with the 'pool'
 151  * @pool: The 'struct dma_pool' associated with the 'dev'
 152  */
 153 struct device_pools {
 154         struct list_head pools;
 155         struct device *dev;
 156         struct dma_pool *pool;
 157 };
 158
 159 /*
 160  * struct ttm_pool_manager - Holds memory pools for fast allocation
 161  *
 162  * @lock: Lock used when adding/removing from pools
 163  * @pools: List of 'struct device' and 'struct dma_pool' tuples.
 164  * @options: Limits for the pool.
 165  * @npools: Total amount of pools in existence.
 166  * @shrinker: The structure used by [un|]register_shrinker
 167  */
 168 struct ttm_pool_manager {
 169         struct mutex            lock;
 170         struct list_head        pools;
 171         struct ttm_pool_opts    options;
 172         unsigned                npools;
 173         struct shrinker         mm_shrink;
 174         struct kobject          kobj;
 175 };
 176
 177 static struct ttm_pool_manager *_manager;
 178
 179 static struct attribute ttm_page_pool_max = {
 180         .name = "pool_max_size",
 181         .mode = S_IRUGO | S_IWUSR
 182 };
 183 static struct attribute ttm_page_pool_small = {
 184         .name = "pool_small_allocation",
 185         .mode = S_IRUGO | S_IWUSR
 186 };
 187 static struct attribute ttm_page_pool_alloc_size = {
 188         .name = "pool_allocation_size",
 189         .mode = S_IRUGO | S_IWUSR
 190 };
 191
 192 static struct attribute *ttm_pool_attrs[] = {
 193         &ttm_page_pool_max,
 194         &ttm_page_pool_small,
 195         &ttm_page_pool_alloc_size,
 196         NULL
 197 };
 198
 199 static void ttm_pool_kobj_release(struct kobject *kobj)
 200 {
 201         struct ttm_pool_manager *m =
 202                 container_of(kobj, struct ttm_pool_manager, kobj);
 203         kfree(m);
 204 }
 205
 206 static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
 207                               const char *buffer, size_t size)
 208 {
 209         struct ttm_pool_manager *m =
 210                 container_of(kobj, struct ttm_pool_manager, kobj);
 211         int chars;
 212         unsigned val;
 213         chars = sscanf(buffer, "%u", &val);
 214         if (chars == 0)
 215                 return size;
 216
 217         /* Convert kb to number of pages */
 218         val = val / (PAGE_SIZE >> 10);
 219
 220         if (attr == &ttm_page_pool_max)
 221                 m->options.max_size = val;
 222         else if (attr == &ttm_page_pool_small)
 223                 m->options.small = val;
 224         else if (attr == &ttm_page_pool_alloc_size) {
 225                 if (val > NUM_PAGES_TO_ALLOC*8) {
 226                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 227                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 228                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 229                         return size;
 230                 } else if (val > NUM_PAGES_TO_ALLOC) {
 231                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 232                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 233                 }
 234                 m->options.alloc_size = val;
 235         }
 236
 237         return size;
 238 }
 239
 240 static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
 241                              char *buffer)
 242 {
 243         struct ttm_pool_manager *m =
 244                 container_of(kobj, struct ttm_pool_manager, kobj);
 245         unsigned val = 0;
 246
 247         if (attr == &ttm_page_pool_max)
 248                 val = m->options.max_size;
 249         else if (attr == &ttm_page_pool_small)
 250                 val = m->options.small;
 251         else if (attr == &ttm_page_pool_alloc_size)
 252                 val = m->options.alloc_size;
 253
 254         val = val * (PAGE_SIZE >> 10);
 255
 256         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 257 }
 258
 259 static const struct sysfs_ops ttm_pool_sysfs_ops = {
 260         .show = &ttm_pool_show,
 261         .store = &ttm_pool_store,
 262 };
 263
 264 static struct kobj_type ttm_pool_kobj_type = {
 265         .release = &ttm_pool_kobj_release,
 266         .sysfs_ops = &ttm_pool_sysfs_ops,
 267         .default_attrs = ttm_pool_attrs,
 268 };
 269
 270 #ifndef CONFIG_X86
 271 static int set_pages_array_wb(struct page **pages, int addrinarray)
 272 {
 273 #if IS_ENABLED(CONFIG_AGP)
 274         int i;
 275
 276         for (i = 0; i < addrinarray; i++)
 277                 unmap_page_from_agp(pages[i]);
 278 #endif
 279         return 0;
 280 }
 281
 282 static int set_pages_array_wc(struct page **pages, int addrinarray)
 283 {
 284 #if IS_ENABLED(CONFIG_AGP)
 285         int i;
 286
 287         for (i = 0; i < addrinarray; i++)
 288                 map_page_into_agp(pages[i]);
 289 #endif
 290         return 0;
 291 }
 292
 293 static int set_pages_array_uc(struct page **pages, int addrinarray)
 294 {
 295 #if IS_ENABLED(CONFIG_AGP)
 296         int i;
 297
 298         for (i = 0; i < addrinarray; i++)
 299                 map_page_into_agp(pages[i]);
 300 #endif
 301         return 0;
 302 }
 303 #endif /* for !CONFIG_X86 */
 304
 305 static int ttm_set_pages_caching(struct dma_pool *pool,
 306                                  struct page **pages, unsigned cpages)
 307 {
 308         int r = 0;
 309         /* Set page caching */
 310         if (pool->type & IS_UC) {
 311                 r = set_pages_array_uc(pages, cpages);
 312                 if (r)
 313                         pr_err("%s: Failed to set %d pages to uc!\n",
 314                                pool->dev_name, cpages);
 315         }
 316         if (pool->type & IS_WC) {
 317                 r = set_pages_array_wc(pages, cpages);
 318                 if (r)
 319                         pr_err("%s: Failed to set %d pages to wc!\n",
 320                                pool->dev_name, cpages);
 321         }
 322         return r;
 323 }
 324
 325 static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
 326 {
 327         dma_addr_t dma = d_page->dma;
 328         d_page->vaddr &= ~VADDR_FLAG_HUGE_POOL;
 329         dma_free_coherent(pool->dev, pool->size, (void *)d_page->vaddr, dma);
 330
 331         kfree(d_page);
 332         d_page = NULL;
 333 }
 334 static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
 335 {
 336         struct dma_page *d_page;
 337         unsigned long attrs = 0;
 338         void *vaddr;
 339
 340         d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
 341         if (!d_page)
 342                 return NULL;
 343
 344         if (pool->type & IS_HUGE)
 345                 attrs = DMA_ATTR_NO_WARN;
 346
 347         vaddr = dma_alloc_attrs(pool->dev, pool->size, &d_page->dma,
 348                                 pool->gfp_flags, attrs);
 349         if (vaddr) {
 350                 if (is_vmalloc_addr(vaddr))
 351                         d_page->p = vmalloc_to_page(vaddr);
 352                 else
 353                         d_page->p = virt_to_page(vaddr);
 354                 d_page->vaddr = (unsigned long)vaddr;
 355                 if (pool->type & IS_HUGE)
 356                         d_page->vaddr |= VADDR_FLAG_HUGE_POOL;
 357         } else {
 358                 kfree(d_page);
 359                 d_page = NULL;
 360         }
 361         return d_page;
 362 }
 363 static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
 364 {
 365         enum pool_type type = IS_UNDEFINED;
 366
 367         if (flags & TTM_PAGE_FLAG_DMA32)
 368                 type |= IS_DMA32;
 369         if (cstate == tt_cached)
 370                 type |= IS_CACHED;
 371         else if (cstate == tt_uncached)
 372                 type |= IS_UC;
 373         else
 374                 type |= IS_WC;
 375
 376         return type;
 377 }
 378
 379 static void ttm_pool_update_free_locked(struct dma_pool *pool,
 380                                         unsigned freed_pages)
 381 {
 382         pool->npages_free -= freed_pages;
 383         pool->nfrees += freed_pages;
 384
 385 }
 386
 387 /* set memory back to wb and free the pages. */
 388 static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
 389 {
 390         struct page *page = d_page->p;
 391         unsigned i, num_pages;
 392         int ret;
 393
 394         /* Don't set WB on WB page pool. */
 395         if (!(pool->type & IS_CACHED)) {
 396                 num_pages = pool->size / PAGE_SIZE;
 397                 for (i = 0; i < num_pages; ++i, ++page) {
 398                         ret = set_pages_array_wb(&page, 1);
 399                         if (ret) {
 400                                 pr_err("%s: Failed to set %d pages to wb!\n",
 401                                        pool->dev_name, 1);
 402                         }
 403                 }
 404         }
 405
 406         list_del(&d_page->page_list);
 407         __ttm_dma_free_page(pool, d_page);
 408 }
 409
 410 static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
 411                               struct page *pages[], unsigned npages)
 412 {
 413         struct dma_page *d_page, *tmp;
 414
 415         if (pool->type & IS_HUGE) {
 416                 list_for_each_entry_safe(d_page, tmp, d_pages, page_list)
 417                         ttm_dma_page_put(pool, d_page);
 418
 419                 return;
 420         }
 421
 422         /* Don't set WB on WB page pool. */
 423         if (npages && !(pool->type & IS_CACHED) &&
 424             set_pages_array_wb(pages, npages))
 425                 pr_err("%s: Failed to set %d pages to wb!\n",
 426                        pool->dev_name, npages);
 427
 428         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 429                 list_del(&d_page->page_list);
 430                 __ttm_dma_free_page(pool, d_page);
 431         }
 432 }
 433
 434 /*
 435  * Free pages from pool.
 436  *
 437  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 438  * number of pages in one go.
 439  *
 440  * @pool: to free the pages from
 441  * @nr_free: If set to true will free all pages in pool
 442  * @use_static: Safe to use static buffer
 443  **/
 444 static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
 445                                        bool use_static)
 446 {
 447         static struct page *static_buf[NUM_PAGES_TO_ALLOC];
 448         unsigned long irq_flags;
 449         struct dma_page *dma_p, *tmp;
 450         struct page **pages_to_free;
 451         struct list_head d_pages;
 452         unsigned freed_pages = 0,
 453                  npages_to_free = nr_free;
 454
 455         if (NUM_PAGES_TO_ALLOC < nr_free)
 456                 npages_to_free = NUM_PAGES_TO_ALLOC;
 457 #if 0
 458         if (nr_free > 1) {
 459                 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
 460                          pool->dev_name, pool->name, current->pid,
 461                          npages_to_free, nr_free);
 462         }
 463 #endif
 464         if (use_static)
 465                 pages_to_free = static_buf;
 466         else
 467                 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 468                                         GFP_KERNEL);
 469
 470         if (!pages_to_free) {
 471                 pr_debug("%s: Failed to allocate memory for pool free operation\n",
 472                        pool->dev_name);
 473                 return 0;
 474         }
 475         INIT_LIST_HEAD(&d_pages);
 476 restart:
 477         spin_lock_irqsave(&pool->lock, irq_flags);
 478
 479         /* We picking the oldest ones off the list */
 480         list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
 481                                          page_list) {
 482                 if (freed_pages >= npages_to_free)
 483                         break;
 484
 485                 /* Move the dma_page from one list to another. */
 486                 list_move(&dma_p->page_list, &d_pages);
 487
 488                 pages_to_free[freed_pages++] = dma_p->p;
 489                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 490                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 491
 492                         ttm_pool_update_free_locked(pool, freed_pages);
 493                         /**
 494                          * Because changing page caching is costly
 495                          * we unlock the pool to prevent stalling.
 496                          */
 497                         spin_unlock_irqrestore(&pool->lock, irq_flags);
 498
 499                         ttm_dma_pages_put(pool, &d_pages, pages_to_free,
 500                                           freed_pages);
 501
 502                         INIT_LIST_HEAD(&d_pages);
 503
 504                         if (likely(nr_free != FREE_ALL_PAGES))
 505                                 nr_free -= freed_pages;
 506
 507                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 508                                 npages_to_free = nr_free;
 509                         else
 510                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 511
 512                         freed_pages = 0;
 513
 514                         /* free all so restart the processing */
 515                         if (nr_free)
 516                                 goto restart;
 517
 518                         /* Not allowed to fall through or break because
 519                          * following context is inside spinlock while we are
 520                          * outside here.
 521                          */
 522                         goto out;
 523
 524                 }
 525         }
 526
 527         /* remove range of pages from the pool */
 528         if (freed_pages) {
 529                 ttm_pool_update_free_locked(pool, freed_pages);
 530                 nr_free -= freed_pages;
 531         }
 532
 533         spin_unlock_irqrestore(&pool->lock, irq_flags);
 534
 535         if (freed_pages)
 536                 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
 537 out:
 538         if (pages_to_free != static_buf)
 539                 kfree(pages_to_free);
 540         return nr_free;
 541 }
 542
 543 static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
 544 {
 545         struct device_pools *p;
 546         struct dma_pool *pool;
 547
 548         if (!dev)
 549                 return;
 550
 551         mutex_lock(&_manager->lock);
 552         list_for_each_entry_reverse(p, &_manager->pools, pools) {
 553                 if (p->dev != dev)
 554                         continue;
 555                 pool = p->pool;
 556                 if (pool->type != type)
 557                         continue;
 558
 559                 list_del(&p->pools);
 560                 kfree(p);
 561                 _manager->npools--;
 562                 break;
 563         }
 564         list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
 565                 if (pool->type != type)
 566                         continue;
 567                 /* Takes a spinlock.. */
 568                 /* OK to use static buffer since global mutex is held. */
 569                 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, true);
 570                 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
 571                 /* This code path is called after _all_ references to the
 572                  * struct device has been dropped - so nobody should be
 573                  * touching it. In case somebody is trying to _add_ we are
 574                  * guarded by the mutex. */
 575                 list_del(&pool->pools);
 576                 kfree(pool);
 577                 break;
 578         }
 579         mutex_unlock(&_manager->lock);
 580 }
 581
 582 /*
 583  * On free-ing of the 'struct device' this deconstructor is run.
 584  * Albeit the pool might have already been freed earlier.
 585  */
 586 static void ttm_dma_pool_release(struct device *dev, void *res)
 587 {
 588         struct dma_pool *pool = *(struct dma_pool **)res;
 589
 590         if (pool)
 591                 ttm_dma_free_pool(dev, pool->type);
 592 }
 593
 594 static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
 595 {
 596         return *(struct dma_pool **)res == match_data;
 597 }
 598
 599 static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
 600                                           enum pool_type type)
 601 {
 602         const char *n[] = {"wc", "uc", "cached", " dma32", "huge"};
 603         enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_HUGE};
 604         struct device_pools *sec_pool = NULL;
 605         struct dma_pool *pool = NULL, **ptr;
 606         unsigned i;
 607         int ret = -ENODEV;
 608         char *p;
 609
 610         if (!dev)
 611                 return NULL;
 612
 613         ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
 614         if (!ptr)
 615                 return NULL;
 616
 617         ret = -ENOMEM;
 618
 619         pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
 620                             dev_to_node(dev));
 621         if (!pool)
 622                 goto err_mem;
 623
 624         sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
 625                                 dev_to_node(dev));
 626         if (!sec_pool)
 627                 goto err_mem;
 628
 629         INIT_LIST_HEAD(&sec_pool->pools);
 630         sec_pool->dev = dev;
 631         sec_pool->pool =  pool;
 632
 633         INIT_LIST_HEAD(&pool->free_list);
 634         INIT_LIST_HEAD(&pool->pools);
 635         spin_lock_init(&pool->lock);
 636         pool->dev = dev;
 637         pool->npages_free = pool->npages_in_use = 0;
 638         pool->nfrees = 0;
 639         pool->gfp_flags = flags;
 640         if (type & IS_HUGE)
 641 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 642                 pool->size = HPAGE_PMD_SIZE;
 643 #else
 644                 BUG();
 645 #endif
 646         else
 647                 pool->size = PAGE_SIZE;
 648         pool->type = type;
 649         pool->nrefills = 0;
 650         p = pool->name;
 651         for (i = 0; i < ARRAY_SIZE(t); i++) {
 652                 if (type & t[i]) {
 653                         p += snprintf(p, sizeof(pool->name) - (p - pool->name),
 654                                       "%s", n[i]);
 655                 }
 656         }
 657         *p = 0;
 658         /* We copy the name for pr_ calls b/c when dma_pool_destroy is called
 659          * - the kobj->name has already been deallocated.*/
 660         snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
 661                  dev_driver_string(dev), dev_name(dev));
 662         mutex_lock(&_manager->lock);
 663         /* You can get the dma_pool from either the global: */
 664         list_add(&sec_pool->pools, &_manager->pools);
 665         _manager->npools++;
 666         /* or from 'struct device': */
 667         list_add(&pool->pools, &dev->dma_pools);
 668         mutex_unlock(&_manager->lock);
 669
 670         *ptr = pool;
 671         devres_add(dev, ptr);
 672
 673         return pool;
 674 err_mem:
 675         devres_free(ptr);
 676         kfree(sec_pool);
 677         kfree(pool);
 678         return ERR_PTR(ret);
 679 }
 680
 681 static struct dma_pool *ttm_dma_find_pool(struct device *dev,
 682                                           enum pool_type type)
 683 {
 684         struct dma_pool *pool, *tmp, *found = NULL;
 685
 686         if (type == IS_UNDEFINED)
 687                 return found;
 688
 689         /* NB: We iterate on the 'struct dev' which has no spinlock, but
 690          * it does have a kref which we have taken. The kref is taken during
 691          * graphic driver loading - in the drm_pci_init it calls either
 692          * pci_dev_get or pci_register_driver which both end up taking a kref
 693          * on 'struct device'.
 694          *
 695          * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
 696          * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
 697          * thing is at that point of time there are no pages associated with the
 698          * driver so this function will not be called.
 699          */
 700         list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) {
 701                 if (pool->type != type)
 702                         continue;
 703                 found = pool;
 704                 break;
 705         }
 706         return found;
 707 }
 708
 709 /*
 710  * Free pages the pages that failed to change the caching state. If there
 711  * are pages that have changed their caching state already put them to the
 712  * pool.
 713  */
 714 static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
 715                                                  struct list_head *d_pages,
 716                                                  struct page **failed_pages,
 717                                                  unsigned cpages)
 718 {
 719         struct dma_page *d_page, *tmp;
 720         struct page *p;
 721         unsigned i = 0;
 722
 723         p = failed_pages[0];
 724         if (!p)
 725                 return;
 726         /* Find the failed page. */
 727         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 728                 if (d_page->p != p)
 729                         continue;
 730                 /* .. and then progress over the full list. */
 731                 list_del(&d_page->page_list);
 732                 __ttm_dma_free_page(pool, d_page);
 733                 if (++i < cpages)
 734                         p = failed_pages[i];
 735                 else
 736                         break;
 737         }
 738
 739 }
 740
 741 /*
 742  * Allocate 'count' pages, and put 'need' number of them on the
 743  * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
 744  * The full list of pages should also be on 'd_pages'.
 745  * We return zero for success, and negative numbers as errors.
 746  */
 747 static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
 748                                         struct list_head *d_pages,
 749                                         unsigned count)
 750 {
 751         struct page **caching_array;
 752         struct dma_page *dma_p;
 753         struct page *p;
 754         int r = 0;
 755         unsigned i, j, npages, cpages;
 756         unsigned max_cpages = min(count,
 757                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 758
 759         /* allocate array for page caching change */
 760         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 761
 762         if (!caching_array) {
 763                 pr_debug("%s: Unable to allocate table for new pages\n",
 764                        pool->dev_name);
 765                 return -ENOMEM;
 766         }
 767
 768         if (count > 1) {
 769                 pr_debug("%s: (%s:%d) Getting %d pages\n",
 770                          pool->dev_name, pool->name, current->pid, count);
 771         }
 772
 773         for (i = 0, cpages = 0; i < count; ++i) {
 774                 dma_p = __ttm_dma_alloc_page(pool);
 775                 if (!dma_p) {
 776                         pr_debug("%s: Unable to get page %u\n",
 777                                  pool->dev_name, i);
 778
 779                         /* store already allocated pages in the pool after
 780                          * setting the caching state */
 781                         if (cpages) {
 782                                 r = ttm_set_pages_caching(pool, caching_array,
 783                                                           cpages);
 784                                 if (r)
 785                                         ttm_dma_handle_caching_state_failure(
 786                                                 pool, d_pages, caching_array,
 787                                                 cpages);
 788                         }
 789                         r = -ENOMEM;
 790                         goto out;
 791                 }
 792                 p = dma_p->p;
 793                 list_add(&dma_p->page_list, d_pages);
 794
 795 #ifdef CONFIG_HIGHMEM
 796                 /* gfp flags of highmem page should never be dma32 so we
 797                  * we should be fine in such case
 798                  */
 799                 if (PageHighMem(p))
 800                         continue;
 801 #endif
 802
 803                 npages = pool->size / PAGE_SIZE;
 804                 for (j = 0; j < npages; ++j) {
 805                         caching_array[cpages++] = p + j;
 806                         if (cpages == max_cpages) {
 807                                 /* Note: Cannot hold the spinlock */
 808                                 r = ttm_set_pages_caching(pool, caching_array,
 809                                                           cpages);
 810                                 if (r) {
 811                                         ttm_dma_handle_caching_state_failure(
 812                                              pool, d_pages, caching_array,
 813                                              cpages);
 814                                         goto out;
 815                                 }
 816                                 cpages = 0;
 817                         }
 818                 }
 819         }
 820
 821         if (cpages) {
 822                 r = ttm_set_pages_caching(pool, caching_array, cpages);
 823                 if (r)
 824                         ttm_dma_handle_caching_state_failure(pool, d_pages,
 825                                         caching_array, cpages);
 826         }
 827 out:
 828         kfree(caching_array);
 829         return r;
 830 }
 831
 832 /*
 833  * @return count of pages still required to fulfill the request.
 834  */
 835 static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
 836                                          unsigned long *irq_flags)
 837 {
 838         unsigned count = _manager->options.small;
 839         int r = pool->npages_free;
 840
 841         if (count > pool->npages_free) {
 842                 struct list_head d_pages;
 843
 844                 INIT_LIST_HEAD(&d_pages);
 845
 846                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 847
 848                 /* Returns how many more are neccessary to fulfill the
 849                  * request. */
 850                 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
 851
 852                 spin_lock_irqsave(&pool->lock, *irq_flags);
 853                 if (!r) {
 854                         /* Add the fresh to the end.. */
 855                         list_splice(&d_pages, &pool->free_list);
 856                         ++pool->nrefills;
 857                         pool->npages_free += count;
 858                         r = count;
 859                 } else {
 860                         struct dma_page *d_page;
 861                         unsigned cpages = 0;
 862
 863                         pr_debug("%s: Failed to fill %s pool (r:%d)!\n",
 864                                  pool->dev_name, pool->name, r);
 865
 866                         list_for_each_entry(d_page, &d_pages, page_list) {
 867                                 cpages++;
 868                         }
 869                         list_splice_tail(&d_pages, &pool->free_list);
 870                         pool->npages_free += cpages;
 871                         r = cpages;
 872                 }
 873         }
 874         return r;
 875 }
 876
 877 /*
 878  * The populate list is actually a stack (not that is matters as TTM
 879  * allocates one page at a time.
 880  * return dma_page pointer if success, otherwise NULL.
 881  */
 882 static struct dma_page *ttm_dma_pool_get_pages(struct dma_pool *pool,
 883                                   struct ttm_dma_tt *ttm_dma,
 884                                   unsigned index)
 885 {
 886         struct dma_page *d_page = NULL;
 887         struct ttm_tt *ttm = &ttm_dma->ttm;
 888         unsigned long irq_flags;
 889         int count;
 890
 891         spin_lock_irqsave(&pool->lock, irq_flags);
 892         count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
 893         if (count) {
 894                 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
 895                 ttm->pages[index] = d_page->p;
 896                 ttm_dma->dma_address[index] = d_page->dma;
 897                 list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
 898                 pool->npages_in_use += 1;
 899                 pool->npages_free -= 1;
 900         }
 901         spin_unlock_irqrestore(&pool->lock, irq_flags);
 902         return d_page;
 903 }
 904
 905 static gfp_t ttm_dma_pool_gfp_flags(struct ttm_dma_tt *ttm_dma, bool huge)
 906 {
 907         struct ttm_tt *ttm = &ttm_dma->ttm;
 908         gfp_t gfp_flags;
 909
 910         if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 911                 gfp_flags = GFP_USER | GFP_DMA32;
 912         else
 913                 gfp_flags = GFP_HIGHUSER;
 914         if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 915                 gfp_flags |= __GFP_ZERO;
 916
 917         if (huge) {
 918                 gfp_flags |= GFP_TRANSHUGE;
 919                 gfp_flags &= ~__GFP_MOVABLE;
 920                 gfp_flags &= ~__GFP_COMP;
 921         }
 922
 923         return gfp_flags;
 924 }
 925
 926 /*
 927  * On success pages list will hold count number of correctly
 928  * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
 929  */
 930 int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
 931                         struct ttm_operation_ctx *ctx)
 932 {
 933         struct ttm_tt *ttm = &ttm_dma->ttm;
 934         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 935         unsigned long num_pages = ttm->num_pages;
 936         struct dma_pool *pool;
 937         struct dma_page *d_page;
 938         enum pool_type type;
 939         unsigned i;
 940         int ret;
 941
 942         if (ttm->state != tt_unpopulated)
 943                 return 0;
 944
 945         INIT_LIST_HEAD(&ttm_dma->pages_list);
 946         i = 0;
 947
 948         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 949
 950 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 951         if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 952                 goto skip_huge;
 953
 954         pool = ttm_dma_find_pool(dev, type | IS_HUGE);
 955         if (!pool) {
 956                 gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, true);
 957
 958                 pool = ttm_dma_pool_init(dev, gfp_flags, type | IS_HUGE);
 959                 if (IS_ERR_OR_NULL(pool))
 960                         goto skip_huge;
 961         }
 962
 963         while (num_pages >= HPAGE_PMD_NR) {
 964                 unsigned j;
 965
 966                 d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
 967                 if (!d_page)
 968                         break;
 969
 970                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 971                                                 pool->size, ctx);
 972                 if (unlikely(ret != 0)) {
 973                         ttm_dma_unpopulate(ttm_dma, dev);
 974                         return -ENOMEM;
 975                 }
 976
 977                 d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
 978                 for (j = i + 1; j < (i + HPAGE_PMD_NR); ++j) {
 979                         ttm->pages[j] = ttm->pages[j - 1] + 1;
 980                         ttm_dma->dma_address[j] = ttm_dma->dma_address[j - 1] +
 981                                 PAGE_SIZE;
 982                 }
 983
 984                 i += HPAGE_PMD_NR;
 985                 num_pages -= HPAGE_PMD_NR;
 986         }
 987
 988 skip_huge:
 989 #endif
 990
 991         pool = ttm_dma_find_pool(dev, type);
 992         if (!pool) {
 993                 gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, false);
 994
 995                 pool = ttm_dma_pool_init(dev, gfp_flags, type);
 996                 if (IS_ERR_OR_NULL(pool))
 997                         return -ENOMEM;
 998         }
 999
1000         while (num_pages) {
1001                 d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
1002                 if (!d_page) {
1003                         ttm_dma_unpopulate(ttm_dma, dev);
1004                         return -ENOMEM;
1005                 }
1006
1007                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
1008                                                 pool->size, ctx);
1009                 if (unlikely(ret != 0)) {
1010                         ttm_dma_unpopulate(ttm_dma, dev);
1011                         return -ENOMEM;
1012                 }
1013
1014                 d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
1015                 ++i;
1016                 --num_pages;
1017         }
1018
1019         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
1020                 ret = ttm_tt_swapin(ttm);
1021                 if (unlikely(ret != 0)) {
1022                         ttm_dma_unpopulate(ttm_dma, dev);
1023                         return ret;
1024                 }
1025         }
1026
1027         ttm->state = tt_unbound;
1028         return 0;
1029 }
1030 EXPORT_SYMBOL_GPL(ttm_dma_populate);
1031
1032 /* Put all pages in pages list to correct pool to wait for reuse */
1033 void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
1034 {
1035         struct ttm_tt *ttm = &ttm_dma->ttm;
1036         struct dma_pool *pool;
1037         struct dma_page *d_page, *next;
1038         enum pool_type type;
1039         bool is_cached = false;
1040         unsigned count, i, npages = 0;
1041         unsigned long irq_flags;
1042
1043         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
1044
1045 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1046         pool = ttm_dma_find_pool(dev, type | IS_HUGE);
1047         if (pool) {
1048                 count = 0;
1049                 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
1050                                          page_list) {
1051                         if (!(d_page->vaddr & VADDR_FLAG_HUGE_POOL))
1052                                 continue;
1053
1054                         count++;
1055                         if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
1056                                 ttm_mem_global_free_page(ttm->glob->mem_glob,
1057                                                          d_page->p, pool->size);
1058                                 d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
1059                         }
1060                         ttm_dma_page_put(pool, d_page);
1061                 }
1062
1063                 spin_lock_irqsave(&pool->lock, irq_flags);
1064                 pool->npages_in_use -= count;
1065                 pool->nfrees += count;
1066                 spin_unlock_irqrestore(&pool->lock, irq_flags);
1067         }
1068 #endif
1069
1070         pool = ttm_dma_find_pool(dev, type);
1071         if (!pool)
1072                 return;
1073
1074         is_cached = (ttm_dma_find_pool(pool->dev,
1075                      ttm_to_type(ttm->page_flags, tt_cached)) == pool);
1076
1077         /* make sure pages array match list and count number of pages */
1078         count = 0;
1079         list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
1080                                  page_list) {
1081                 ttm->pages[count] = d_page->p;
1082                 count++;
1083
1084                 if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
1085                         ttm_mem_global_free_page(ttm->glob->mem_glob,
1086                                                  d_page->p, pool->size);
1087                         d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
1088                 }
1089
1090                 if (is_cached)
1091                         ttm_dma_page_put(pool, d_page);
1092         }
1093
1094         spin_lock_irqsave(&pool->lock, irq_flags);
1095         pool->npages_in_use -= count;
1096         if (is_cached) {
1097                 pool->nfrees += count;
1098         } else {
1099                 pool->npages_free += count;
1100                 list_splice(&ttm_dma->pages_list, &pool->free_list);
1101                 /*
1102                  * Wait to have at at least NUM_PAGES_TO_ALLOC number of pages
1103                  * to free in order to minimize calls to set_memory_wb().
1104                  */
1105                 if (pool->npages_free >= (_manager->options.max_size +
1106                                           NUM_PAGES_TO_ALLOC))
1107                         npages = pool->npages_free - _manager->options.max_size;
1108         }
1109         spin_unlock_irqrestore(&pool->lock, irq_flags);
1110
1111         INIT_LIST_HEAD(&ttm_dma->pages_list);
1112         for (i = 0; i < ttm->num_pages; i++) {
1113                 ttm->pages[i] = NULL;
1114                 ttm_dma->dma_address[i] = 0;
1115         }
1116
1117         /* shrink pool if necessary (only on !is_cached pools)*/
1118         if (npages)
1119                 ttm_dma_page_pool_free(pool, npages, false);
1120         ttm->state = tt_unpopulated;
1121 }
1122 EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
1123
1124 /**
1125  * Callback for mm to request pool to reduce number of page held.
1126  *
1127  * XXX: (dchinner) Deadlock warning!
1128  *
1129  * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
1130  * shrinkers
1131  */
1132 static unsigned long
1133 ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1134 {
1135         static unsigned start_pool;
1136         unsigned idx = 0;
1137         unsigned pool_offset;
1138         unsigned shrink_pages = sc->nr_to_scan;
1139         struct device_pools *p;
1140         unsigned long freed = 0;
1141
1142         if (list_empty(&_manager->pools))
1143                 return SHRINK_STOP;
1144
1145         if (!mutex_trylock(&_manager->lock))
1146                 return SHRINK_STOP;
1147         if (!_manager->npools)
1148                 goto out;
1149         pool_offset = ++start_pool % _manager->npools;
1150         list_for_each_entry(p, &_manager->pools, pools) {
1151                 unsigned nr_free;
1152
1153                 if (!p->dev)
1154                         continue;
1155                 if (shrink_pages == 0)
1156                         break;
1157                 /* Do it in round-robin fashion. */
1158                 if (++idx < pool_offset)
1159                         continue;
1160                 nr_free = shrink_pages;
1161                 /* OK to use static buffer since global mutex is held. */
1162                 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free, true);
1163                 freed += nr_free - shrink_pages;
1164
1165                 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
1166                          p->pool->dev_name, p->pool->name, current->pid,
1167                          nr_free, shrink_pages);
1168         }
1169 out:
1170         mutex_unlock(&_manager->lock);
1171         return freed;
1172 }
1173
1174 static unsigned long
1175 ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
1176 {
1177         struct device_pools *p;
1178         unsigned long count = 0;
1179
1180         if (!mutex_trylock(&_manager->lock))
1181                 return 0;
1182         list_for_each_entry(p, &_manager->pools, pools)
1183                 count += p->pool->npages_free;
1184         mutex_unlock(&_manager->lock);
1185         return count;
1186 }
1187
1188 static int ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
1189 {
1190         manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count;
1191         manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
1192         manager->mm_shrink.seeks = 1;
1193         return register_shrinker(&manager->mm_shrink);
1194 }
1195
1196 static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
1197 {
1198         unregister_shrinker(&manager->mm_shrink);
1199 }
1200
1201 int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1202 {
1203         int ret;
1204
1205         WARN_ON(_manager);
1206
1207         pr_info("Initializing DMA pool allocator\n");
1208
1209         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1210         if (!_manager)
1211                 return -ENOMEM;
1212
1213         mutex_init(&_manager->lock);
1214         INIT_LIST_HEAD(&_manager->pools);
1215
1216         _manager->options.max_size = max_pages;
1217         _manager->options.small = SMALL_ALLOCATION;
1218         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1219
1220         /* This takes care of auto-freeing the _manager */
1221         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1222                                    &glob->kobj, "dma_pool");
1223         if (unlikely(ret != 0))
1224                 goto error;
1225
1226         ret = ttm_dma_pool_mm_shrink_init(_manager);
1227         if (unlikely(ret != 0))
1228                 goto error;
1229         return 0;
1230
1231 error:
1232         kobject_put(&_manager->kobj);
1233         _manager = NULL;
1234         return ret;
1235 }
1236
1237 void ttm_dma_page_alloc_fini(void)
1238 {
1239         struct device_pools *p, *t;
1240
1241         pr_info("Finalizing DMA pool allocator\n");
1242         ttm_dma_pool_mm_shrink_fini(_manager);
1243
1244         list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
1245                 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
1246                         current->pid);
1247                 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
1248                         ttm_dma_pool_match, p->pool));
1249                 ttm_dma_free_pool(p->dev, p->pool->type);
1250         }
1251         kobject_put(&_manager->kobj);
1252         _manager = NULL;
1253 }
1254
1255 int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
1256 {
1257         struct device_pools *p;
1258         struct dma_pool *pool = NULL;
1259
1260         if (!_manager) {
1261                 seq_printf(m, "No pool allocator running.\n");
1262                 return 0;
1263         }
1264         seq_printf(m, "         pool      refills   pages freed    inuse available     name\n");
1265         mutex_lock(&_manager->lock);
1266         list_for_each_entry(p, &_manager->pools, pools) {
1267                 struct device *dev = p->dev;
1268                 if (!dev)
1269                         continue;
1270                 pool = p->pool;
1271                 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
1272                                 pool->name, pool->nrefills,
1273                                 pool->nfrees, pool->npages_in_use,
1274                                 pool->npages_free,
1275                                 pool->dev_name);
1276         }
1277         mutex_unlock(&_manager->lock);
1278         return 0;
1279 }
1280 EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);
1281
1282 #endif