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 <konrad.wilk@oracle.com>
  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
 214         chars = sscanf(buffer, "%u", &val);
 215         if (chars == 0)
 216                 return size;
 217
 218         /* Convert kb to number of pages */
 219         val = val / (PAGE_SIZE >> 10);
 220
 221         if (attr == &ttm_page_pool_max) {
 222                 m->options.max_size = val;
 223         } else if (attr == &ttm_page_pool_small) {
 224                 m->options.small = val;
 225         } else if (attr == &ttm_page_pool_alloc_size) {
 226                 if (val > NUM_PAGES_TO_ALLOC*8) {
 227                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 228                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 229                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 230                         return size;
 231                 } else if (val > NUM_PAGES_TO_ALLOC) {
 232                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 233                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 234                 }
 235                 m->options.alloc_size = val;
 236         }
 237
 238         return size;
 239 }
 240
 241 static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
 242                              char *buffer)
 243 {
 244         struct ttm_pool_manager *m =
 245                 container_of(kobj, struct ttm_pool_manager, kobj);
 246         unsigned val = 0;
 247
 248         if (attr == &ttm_page_pool_max)
 249                 val = m->options.max_size;
 250         else if (attr == &ttm_page_pool_small)
 251                 val = m->options.small;
 252         else if (attr == &ttm_page_pool_alloc_size)
 253                 val = m->options.alloc_size;
 254
 255         val = val * (PAGE_SIZE >> 10);
 256
 257         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 258 }
 259
 260 static const struct sysfs_ops ttm_pool_sysfs_ops = {
 261         .show = &ttm_pool_show,
 262         .store = &ttm_pool_store,
 263 };
 264
 265 static struct kobj_type ttm_pool_kobj_type = {
 266         .release = &ttm_pool_kobj_release,
 267         .sysfs_ops = &ttm_pool_sysfs_ops,
 268         .default_attrs = ttm_pool_attrs,
 269 };
 270
 271 #ifndef CONFIG_X86
 272 static int set_pages_array_wb(struct page **pages, int addrinarray)
 273 {
 274 #if IS_ENABLED(CONFIG_AGP)
 275         int i;
 276
 277         for (i = 0; i < addrinarray; i++)
 278                 unmap_page_from_agp(pages[i]);
 279 #endif
 280         return 0;
 281 }
 282
 283 static int set_pages_array_wc(struct page **pages, int addrinarray)
 284 {
 285 #if IS_ENABLED(CONFIG_AGP)
 286         int i;
 287
 288         for (i = 0; i < addrinarray; i++)
 289                 map_page_into_agp(pages[i]);
 290 #endif
 291         return 0;
 292 }
 293
 294 static int set_pages_array_uc(struct page **pages, int addrinarray)
 295 {
 296 #if IS_ENABLED(CONFIG_AGP)
 297         int i;
 298
 299         for (i = 0; i < addrinarray; i++)
 300                 map_page_into_agp(pages[i]);
 301 #endif
 302         return 0;
 303 }
 304 #endif /* for !CONFIG_X86 */
 305
 306 static int ttm_set_pages_caching(struct dma_pool *pool,
 307                                  struct page **pages, unsigned cpages)
 308 {
 309         int r = 0;
 310         /* Set page caching */
 311         if (pool->type & IS_UC) {
 312                 r = set_pages_array_uc(pages, cpages);
 313                 if (r)
 314                         pr_err("%s: Failed to set %d pages to uc!\n",
 315                                pool->dev_name, cpages);
 316         }
 317         if (pool->type & IS_WC) {
 318                 r = set_pages_array_wc(pages, cpages);
 319                 if (r)
 320                         pr_err("%s: Failed to set %d pages to wc!\n",
 321                                pool->dev_name, cpages);
 322         }
 323         return r;
 324 }
 325
 326 static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
 327 {
 328         dma_addr_t dma = d_page->dma;
 329         d_page->vaddr &= ~VADDR_FLAG_HUGE_POOL;
 330         dma_free_coherent(pool->dev, pool->size, (void *)d_page->vaddr, dma);
 331
 332         kfree(d_page);
 333         d_page = NULL;
 334 }
 335 static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
 336 {
 337         struct dma_page *d_page;
 338         unsigned long attrs = 0;
 339         void *vaddr;
 340
 341         d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
 342         if (!d_page)
 343                 return NULL;
 344
 345         if (pool->type & IS_HUGE)
 346                 attrs = DMA_ATTR_NO_WARN;
 347
 348         vaddr = dma_alloc_attrs(pool->dev, pool->size, &d_page->dma,
 349                                 pool->gfp_flags, attrs);
 350         if (vaddr) {
 351                 if (is_vmalloc_addr(vaddr))
 352                         d_page->p = vmalloc_to_page(vaddr);
 353                 else
 354                         d_page->p = virt_to_page(vaddr);
 355                 d_page->vaddr = (unsigned long)vaddr;
 356                 if (pool->type & IS_HUGE)
 357                         d_page->vaddr |= VADDR_FLAG_HUGE_POOL;
 358         } else {
 359                 kfree(d_page);
 360                 d_page = NULL;
 361         }
 362         return d_page;
 363 }
 364 static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
 365 {
 366         enum pool_type type = IS_UNDEFINED;
 367
 368         if (flags & TTM_PAGE_FLAG_DMA32)
 369                 type |= IS_DMA32;
 370         if (cstate == tt_cached)
 371                 type |= IS_CACHED;
 372         else if (cstate == tt_uncached)
 373                 type |= IS_UC;
 374         else
 375                 type |= IS_WC;
 376
 377         return type;
 378 }
 379
 380 static void ttm_pool_update_free_locked(struct dma_pool *pool,
 381                                         unsigned freed_pages)
 382 {
 383         pool->npages_free -= freed_pages;
 384         pool->nfrees += freed_pages;
 385
 386 }
 387
 388 /* set memory back to wb and free the pages. */
 389 static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
 390 {
 391         struct page *page = d_page->p;
 392         unsigned i, num_pages;
 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                         if (set_pages_array_wb(&page, 1)) {
 399                                 pr_err("%s: Failed to set %d pages to wb!\n",
 400                                        pool->dev_name, 1);
 401                         }
 402                 }
 403         }
 404
 405         list_del(&d_page->page_list);
 406         __ttm_dma_free_page(pool, d_page);
 407 }
 408
 409 static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
 410                               struct page *pages[], unsigned npages)
 411 {
 412         struct dma_page *d_page, *tmp;
 413
 414         if (pool->type & IS_HUGE) {
 415                 list_for_each_entry_safe(d_page, tmp, d_pages, page_list)
 416                         ttm_dma_page_put(pool, d_page);
 417
 418                 return;
 419         }
 420
 421         /* Don't set WB on WB page pool. */
 422         if (npages && !(pool->type & IS_CACHED) &&
 423             set_pages_array_wb(pages, npages))
 424                 pr_err("%s: Failed to set %d pages to wb!\n",
 425                        pool->dev_name, npages);
 426
 427         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 428                 list_del(&d_page->page_list);
 429                 __ttm_dma_free_page(pool, d_page);
 430         }
 431 }
 432
 433 /*
 434  * Free pages from pool.
 435  *
 436  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 437  * number of pages in one go.
 438  *
 439  * @pool: to free the pages from
 440  * @nr_free: If set to true will free all pages in pool
 441  * @use_static: Safe to use static buffer
 442  **/
 443 static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
 444                                        bool use_static)
 445 {
 446         static struct page *static_buf[NUM_PAGES_TO_ALLOC];
 447         unsigned long irq_flags;
 448         struct dma_page *dma_p, *tmp;
 449         struct page **pages_to_free;
 450         struct list_head d_pages;
 451         unsigned freed_pages = 0,
 452                  npages_to_free = nr_free;
 453
 454         if (NUM_PAGES_TO_ALLOC < nr_free)
 455                 npages_to_free = NUM_PAGES_TO_ALLOC;
 456 #if 0
 457         if (nr_free > 1) {
 458                 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
 459                          pool->dev_name, pool->name, current->pid,
 460                          npages_to_free, nr_free);
 461         }
 462 #endif
 463         if (use_static)
 464                 pages_to_free = static_buf;
 465         else
 466                 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 467                                         GFP_KERNEL);
 468
 469         if (!pages_to_free) {
 470                 pr_debug("%s: Failed to allocate memory for pool free operation\n",
 471                        pool->dev_name);
 472                 return 0;
 473         }
 474         INIT_LIST_HEAD(&d_pages);
 475 restart:
 476         spin_lock_irqsave(&pool->lock, irq_flags);
 477
 478         /* We picking the oldest ones off the list */
 479         list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
 480                                          page_list) {
 481                 if (freed_pages >= npages_to_free)
 482                         break;
 483
 484                 /* Move the dma_page from one list to another. */
 485                 list_move(&dma_p->page_list, &d_pages);
 486
 487                 pages_to_free[freed_pages++] = dma_p->p;
 488                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 489                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 490
 491                         ttm_pool_update_free_locked(pool, freed_pages);
 492                         /**
 493                          * Because changing page caching is costly
 494                          * we unlock the pool to prevent stalling.
 495                          */
 496                         spin_unlock_irqrestore(&pool->lock, irq_flags);
 497
 498                         ttm_dma_pages_put(pool, &d_pages, pages_to_free,
 499                                           freed_pages);
 500
 501                         INIT_LIST_HEAD(&d_pages);
 502
 503                         if (likely(nr_free != FREE_ALL_PAGES))
 504                                 nr_free -= freed_pages;
 505
 506                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 507                                 npages_to_free = nr_free;
 508                         else
 509                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 510
 511                         freed_pages = 0;
 512
 513                         /* free all so restart the processing */
 514                         if (nr_free)
 515                                 goto restart;
 516
 517                         /* Not allowed to fall through or break because
 518                          * following context is inside spinlock while we are
 519                          * outside here.
 520                          */
 521                         goto out;
 522
 523                 }
 524         }
 525
 526         /* remove range of pages from the pool */
 527         if (freed_pages) {
 528                 ttm_pool_update_free_locked(pool, freed_pages);
 529                 nr_free -= freed_pages;
 530         }
 531
 532         spin_unlock_irqrestore(&pool->lock, irq_flags);
 533
 534         if (freed_pages)
 535                 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
 536 out:
 537         if (pages_to_free != static_buf)
 538                 kfree(pages_to_free);
 539         return nr_free;
 540 }
 541
 542 static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
 543 {
 544         struct device_pools *p;
 545         struct dma_pool *pool;
 546
 547         if (!dev)
 548                 return;
 549
 550         mutex_lock(&_manager->lock);
 551         list_for_each_entry_reverse(p, &_manager->pools, pools) {
 552                 if (p->dev != dev)
 553                         continue;
 554                 pool = p->pool;
 555                 if (pool->type != type)
 556                         continue;
 557
 558                 list_del(&p->pools);
 559                 kfree(p);
 560                 _manager->npools--;
 561                 break;
 562         }
 563         list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
 564                 if (pool->type != type)
 565                         continue;
 566                 /* Takes a spinlock.. */
 567                 /* OK to use static buffer since global mutex is held. */
 568                 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, true);
 569                 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
 570                 /* This code path is called after _all_ references to the
 571                  * struct device has been dropped - so nobody should be
 572                  * touching it. In case somebody is trying to _add_ we are
 573                  * guarded by the mutex. */
 574                 list_del(&pool->pools);
 575                 kfree(pool);
 576                 break;
 577         }
 578         mutex_unlock(&_manager->lock);
 579 }
 580
 581 /*
 582  * On free-ing of the 'struct device' this deconstructor is run.
 583  * Albeit the pool might have already been freed earlier.
 584  */
 585 static void ttm_dma_pool_release(struct device *dev, void *res)
 586 {
 587         struct dma_pool *pool = *(struct dma_pool **)res;
 588
 589         if (pool)
 590                 ttm_dma_free_pool(dev, pool->type);
 591 }
 592
 593 static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
 594 {
 595         return *(struct dma_pool **)res == match_data;
 596 }
 597
 598 static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
 599                                           enum pool_type type)
 600 {
 601         const char *n[] = {"wc", "uc", "cached", " dma32", "huge"};
 602         enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_HUGE};
 603         struct device_pools *sec_pool = NULL;
 604         struct dma_pool *pool = NULL, **ptr;
 605         unsigned i;
 606         int ret = -ENODEV;
 607         char *p;
 608
 609         if (!dev)
 610                 return NULL;
 611
 612         ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
 613         if (!ptr)
 614                 return NULL;
 615
 616         ret = -ENOMEM;
 617
 618         pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
 619                             dev_to_node(dev));
 620         if (!pool)
 621                 goto err_mem;
 622
 623         sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
 624                                 dev_to_node(dev));
 625         if (!sec_pool)
 626                 goto err_mem;
 627
 628         INIT_LIST_HEAD(&sec_pool->pools);
 629         sec_pool->dev = dev;
 630         sec_pool->pool =  pool;
 631
 632         INIT_LIST_HEAD(&pool->free_list);
 633         INIT_LIST_HEAD(&pool->pools);
 634         spin_lock_init(&pool->lock);
 635         pool->dev = dev;
 636         pool->npages_free = pool->npages_in_use = 0;
 637         pool->nfrees = 0;
 638         pool->gfp_flags = flags;
 639         if (type & IS_HUGE)
 640 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 641                 pool->size = HPAGE_PMD_SIZE;
 642 #else
 643                 BUG();
 644 #endif
 645         else
 646                 pool->size = PAGE_SIZE;
 647         pool->type = type;
 648         pool->nrefills = 0;
 649         p = pool->name;
 650         for (i = 0; i < ARRAY_SIZE(t); i++) {
 651                 if (type & t[i]) {
 652                         p += snprintf(p, sizeof(pool->name) - (p - pool->name),
 653                                       "%s", n[i]);
 654                 }
 655         }
 656         *p = 0;
 657         /* We copy the name for pr_ calls b/c when dma_pool_destroy is called
 658          * - the kobj->name has already been deallocated.*/
 659         snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
 660                  dev_driver_string(dev), dev_name(dev));
 661         mutex_lock(&_manager->lock);
 662         /* You can get the dma_pool from either the global: */
 663         list_add(&sec_pool->pools, &_manager->pools);
 664         _manager->npools++;
 665         /* or from 'struct device': */
 666         list_add(&pool->pools, &dev->dma_pools);
 667         mutex_unlock(&_manager->lock);
 668
 669         *ptr = pool;
 670         devres_add(dev, ptr);
 671
 672         return pool;
 673 err_mem:
 674         devres_free(ptr);
 675         kfree(sec_pool);
 676         kfree(pool);
 677         return ERR_PTR(ret);
 678 }
 679
 680 static struct dma_pool *ttm_dma_find_pool(struct device *dev,
 681                                           enum pool_type type)
 682 {
 683         struct dma_pool *pool, *tmp;
 684
 685         if (type == IS_UNDEFINED)
 686                 return NULL;
 687
 688         /* NB: We iterate on the 'struct dev' which has no spinlock, but
 689          * it does have a kref which we have taken. The kref is taken during
 690          * graphic driver loading - in the drm_pci_init it calls either
 691          * pci_dev_get or pci_register_driver which both end up taking a kref
 692          * on 'struct device'.
 693          *
 694          * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
 695          * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
 696          * thing is at that point of time there are no pages associated with the
 697          * driver so this function will not be called.
 698          */
 699         list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools)
 700                 if (pool->type == type)
 701                         return pool;
 702         return NULL;
 703 }
 704
 705 /*
 706  * Free pages the pages that failed to change the caching state. If there
 707  * are pages that have changed their caching state already put them to the
 708  * pool.
 709  */
 710 static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
 711                                                  struct list_head *d_pages,
 712                                                  struct page **failed_pages,
 713                                                  unsigned cpages)
 714 {
 715         struct dma_page *d_page, *tmp;
 716         struct page *p;
 717         unsigned i = 0;
 718
 719         p = failed_pages[0];
 720         if (!p)
 721                 return;
 722         /* Find the failed page. */
 723         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 724                 if (d_page->p != p)
 725                         continue;
 726                 /* .. and then progress over the full list. */
 727                 list_del(&d_page->page_list);
 728                 __ttm_dma_free_page(pool, d_page);
 729                 if (++i < cpages)
 730                         p = failed_pages[i];
 731                 else
 732                         break;
 733         }
 734
 735 }
 736
 737 /*
 738  * Allocate 'count' pages, and put 'need' number of them on the
 739  * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
 740  * The full list of pages should also be on 'd_pages'.
 741  * We return zero for success, and negative numbers as errors.
 742  */
 743 static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
 744                                         struct list_head *d_pages,
 745                                         unsigned count)
 746 {
 747         struct page **caching_array;
 748         struct dma_page *dma_p;
 749         struct page *p;
 750         int r = 0;
 751         unsigned i, j, npages, cpages;
 752         unsigned max_cpages = min(count,
 753                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 754
 755         /* allocate array for page caching change */
 756         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 757
 758         if (!caching_array) {
 759                 pr_debug("%s: Unable to allocate table for new pages\n",
 760                        pool->dev_name);
 761                 return -ENOMEM;
 762         }
 763
 764         if (count > 1)
 765                 pr_debug("%s: (%s:%d) Getting %d pages\n",
 766                          pool->dev_name, pool->name, current->pid, count);
 767
 768         for (i = 0, cpages = 0; i < count; ++i) {
 769                 dma_p = __ttm_dma_alloc_page(pool);
 770                 if (!dma_p) {
 771                         pr_debug("%s: Unable to get page %u\n",
 772                                  pool->dev_name, i);
 773
 774                         /* store already allocated pages in the pool after
 775                          * setting the caching state */
 776                         if (cpages) {
 777                                 r = ttm_set_pages_caching(pool, caching_array,
 778                                                           cpages);
 779                                 if (r)
 780                                         ttm_dma_handle_caching_state_failure(
 781                                                 pool, d_pages, caching_array,
 782                                                 cpages);
 783                         }
 784                         r = -ENOMEM;
 785                         goto out;
 786                 }
 787                 p = dma_p->p;
 788                 list_add(&dma_p->page_list, d_pages);
 789
 790 #ifdef CONFIG_HIGHMEM
 791                 /* gfp flags of highmem page should never be dma32 so we
 792                  * we should be fine in such case
 793                  */
 794                 if (PageHighMem(p))
 795                         continue;
 796 #endif
 797
 798                 npages = pool->size / PAGE_SIZE;
 799                 for (j = 0; j < npages; ++j) {
 800                         caching_array[cpages++] = p + j;
 801                         if (cpages == max_cpages) {
 802                                 /* Note: Cannot hold the spinlock */
 803                                 r = ttm_set_pages_caching(pool, caching_array,
 804                                                           cpages);
 805                                 if (r) {
 806                                         ttm_dma_handle_caching_state_failure(
 807                                              pool, d_pages, caching_array,
 808                                              cpages);
 809                                         goto out;
 810                                 }
 811                                 cpages = 0;
 812                         }
 813                 }
 814         }
 815
 816         if (cpages) {
 817                 r = ttm_set_pages_caching(pool, caching_array, cpages);
 818                 if (r)
 819                         ttm_dma_handle_caching_state_failure(pool, d_pages,
 820                                         caching_array, cpages);
 821         }
 822 out:
 823         kfree(caching_array);
 824         return r;
 825 }
 826
 827 /*
 828  * @return count of pages still required to fulfill the request.
 829  */
 830 static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
 831                                          unsigned long *irq_flags)
 832 {
 833         unsigned count = _manager->options.small;
 834         int r = pool->npages_free;
 835
 836         if (count > pool->npages_free) {
 837                 struct list_head d_pages;
 838
 839                 INIT_LIST_HEAD(&d_pages);
 840
 841                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 842
 843                 /* Returns how many more are neccessary to fulfill the
 844                  * request. */
 845                 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
 846
 847                 spin_lock_irqsave(&pool->lock, *irq_flags);
 848                 if (!r) {
 849                         /* Add the fresh to the end.. */
 850                         list_splice(&d_pages, &pool->free_list);
 851                         ++pool->nrefills;
 852                         pool->npages_free += count;
 853                         r = count;
 854                 } else {
 855                         struct dma_page *d_page;
 856                         unsigned cpages = 0;
 857
 858                         pr_debug("%s: Failed to fill %s pool (r:%d)!\n",
 859                                  pool->dev_name, pool->name, r);
 860
 861                         list_for_each_entry(d_page, &d_pages, page_list) {
 862                                 cpages++;
 863                         }
 864                         list_splice_tail(&d_pages, &pool->free_list);
 865                         pool->npages_free += cpages;
 866                         r = cpages;
 867                 }
 868         }
 869         return r;
 870 }
 871
 872 /*
 873  * The populate list is actually a stack (not that is matters as TTM
 874  * allocates one page at a time.
 875  * return dma_page pointer if success, otherwise NULL.
 876  */
 877 static struct dma_page *ttm_dma_pool_get_pages(struct dma_pool *pool,
 878                                   struct ttm_dma_tt *ttm_dma,
 879                                   unsigned index)
 880 {
 881         struct dma_page *d_page = NULL;
 882         struct ttm_tt *ttm = &ttm_dma->ttm;
 883         unsigned long irq_flags;
 884         int count;
 885
 886         spin_lock_irqsave(&pool->lock, irq_flags);
 887         count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
 888         if (count) {
 889                 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
 890                 ttm->pages[index] = d_page->p;
 891                 ttm_dma->dma_address[index] = d_page->dma;
 892                 list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
 893                 pool->npages_in_use += 1;
 894                 pool->npages_free -= 1;
 895         }
 896         spin_unlock_irqrestore(&pool->lock, irq_flags);
 897         return d_page;
 898 }
 899
 900 static gfp_t ttm_dma_pool_gfp_flags(struct ttm_dma_tt *ttm_dma, bool huge)
 901 {
 902         struct ttm_tt *ttm = &ttm_dma->ttm;
 903         gfp_t gfp_flags;
 904
 905         if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 906                 gfp_flags = GFP_USER | GFP_DMA32;
 907         else
 908                 gfp_flags = GFP_HIGHUSER;
 909         if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 910                 gfp_flags |= __GFP_ZERO;
 911
 912         if (huge) {
 913                 gfp_flags |= GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
 914                         __GFP_KSWAPD_RECLAIM;
 915                 gfp_flags &= ~__GFP_MOVABLE;
 916                 gfp_flags &= ~__GFP_COMP;
 917         }
 918
 919         if (ttm->page_flags & TTM_PAGE_FLAG_NO_RETRY)
 920                 gfp_flags |= __GFP_RETRY_MAYFAIL;
 921
 922         return gfp_flags;
 923 }
 924
 925 /*
 926  * On success pages list will hold count number of correctly
 927  * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
 928  */
 929 int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
 930                         struct ttm_operation_ctx *ctx)
 931 {
 932         struct ttm_tt *ttm = &ttm_dma->ttm;
 933         struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
 934         unsigned long num_pages = ttm->num_pages;
 935         struct dma_pool *pool;
 936         struct dma_page *d_page;
 937         enum pool_type type;
 938         unsigned i;
 939         int ret;
 940
 941         if (ttm->state != tt_unpopulated)
 942                 return 0;
 943
 944         if (ttm_check_under_lowerlimit(mem_glob, num_pages, ctx))
 945                 return -ENOMEM;
 946
 947         INIT_LIST_HEAD(&ttm_dma->pages_list);
 948         i = 0;
 949
 950         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 951
 952 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 953         if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 954                 goto skip_huge;
 955
 956         pool = ttm_dma_find_pool(dev, type | IS_HUGE);
 957         if (!pool) {
 958                 gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, true);
 959
 960                 pool = ttm_dma_pool_init(dev, gfp_flags, type | IS_HUGE);
 961                 if (IS_ERR_OR_NULL(pool))
 962                         goto skip_huge;
 963         }
 964
 965         while (num_pages >= HPAGE_PMD_NR) {
 966                 unsigned j;
 967
 968                 d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
 969                 if (!d_page)
 970                         break;
 971
 972                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 973                                                 pool->size, ctx);
 974                 if (unlikely(ret != 0)) {
 975                         ttm_dma_unpopulate(ttm_dma, dev);
 976                         return -ENOMEM;
 977                 }
 978
 979                 d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
 980                 for (j = i + 1; j < (i + HPAGE_PMD_NR); ++j) {
 981                         ttm->pages[j] = ttm->pages[j - 1] + 1;
 982                         ttm_dma->dma_address[j] = ttm_dma->dma_address[j - 1] +
 983                                 PAGE_SIZE;
 984                 }
 985
 986                 i += HPAGE_PMD_NR;
 987                 num_pages -= HPAGE_PMD_NR;
 988         }
 989
 990 skip_huge:
 991 #endif
 992
 993         pool = ttm_dma_find_pool(dev, type);
 994         if (!pool) {
 995                 gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, false);
 996
 997                 pool = ttm_dma_pool_init(dev, gfp_flags, type);
 998                 if (IS_ERR_OR_NULL(pool))
 999                         return -ENOMEM;
1000         }
1001
1002         while (num_pages) {
1003                 d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
1004                 if (!d_page) {
1005                         ttm_dma_unpopulate(ttm_dma, dev);
1006                         return -ENOMEM;
1007                 }
1008
1009                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
1010                                                 pool->size, ctx);
1011                 if (unlikely(ret != 0)) {
1012                         ttm_dma_unpopulate(ttm_dma, dev);
1013                         return -ENOMEM;
1014                 }
1015
1016                 d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
1017                 ++i;
1018                 --num_pages;
1019         }
1020
1021         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
1022                 ret = ttm_tt_swapin(ttm);
1023                 if (unlikely(ret != 0)) {
1024                         ttm_dma_unpopulate(ttm_dma, dev);
1025                         return ret;
1026                 }
1027         }
1028
1029         ttm->state = tt_unbound;
1030         return 0;
1031 }
1032 EXPORT_SYMBOL_GPL(ttm_dma_populate);
1033
1034 /* Put all pages in pages list to correct pool to wait for reuse */
1035 void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
1036 {
1037         struct ttm_tt *ttm = &ttm_dma->ttm;
1038         struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
1039         struct dma_pool *pool;
1040         struct dma_page *d_page, *next;
1041         enum pool_type type;
1042         bool is_cached = false;
1043         unsigned count, i, npages = 0;
1044         unsigned long irq_flags;
1045
1046         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
1047
1048 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1049         pool = ttm_dma_find_pool(dev, type | IS_HUGE);
1050         if (pool) {
1051                 count = 0;
1052                 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
1053                                          page_list) {
1054                         if (!(d_page->vaddr & VADDR_FLAG_HUGE_POOL))
1055                                 continue;
1056
1057                         count++;
1058                         if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
1059                                 ttm_mem_global_free_page(mem_glob, d_page->p,
1060                                                          pool->size);
1061                                 d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
1062                         }
1063                         ttm_dma_page_put(pool, d_page);
1064                 }
1065
1066                 spin_lock_irqsave(&pool->lock, irq_flags);
1067                 pool->npages_in_use -= count;
1068                 pool->nfrees += count;
1069                 spin_unlock_irqrestore(&pool->lock, irq_flags);
1070         }
1071 #endif
1072
1073         pool = ttm_dma_find_pool(dev, type);
1074         if (!pool)
1075                 return;
1076
1077         is_cached = (ttm_dma_find_pool(pool->dev,
1078                      ttm_to_type(ttm->page_flags, tt_cached)) == pool);
1079
1080         /* make sure pages array match list and count number of pages */
1081         count = 0;
1082         list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
1083                                  page_list) {
1084                 ttm->pages[count] = d_page->p;
1085                 count++;
1086
1087                 if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
1088                         ttm_mem_global_free_page(mem_glob, d_page->p,
1089                                                  pool->size);
1090                         d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
1091                 }
1092
1093                 if (is_cached)
1094                         ttm_dma_page_put(pool, d_page);
1095         }
1096
1097         spin_lock_irqsave(&pool->lock, irq_flags);
1098         pool->npages_in_use -= count;
1099         if (is_cached) {
1100                 pool->nfrees += count;
1101         } else {
1102                 pool->npages_free += count;
1103                 list_splice(&ttm_dma->pages_list, &pool->free_list);
1104                 /*
1105                  * Wait to have at at least NUM_PAGES_TO_ALLOC number of pages
1106                  * to free in order to minimize calls to set_memory_wb().
1107                  */
1108                 if (pool->npages_free >= (_manager->options.max_size +
1109                                           NUM_PAGES_TO_ALLOC))
1110                         npages = pool->npages_free - _manager->options.max_size;
1111         }
1112         spin_unlock_irqrestore(&pool->lock, irq_flags);
1113
1114         INIT_LIST_HEAD(&ttm_dma->pages_list);
1115         for (i = 0; i < ttm->num_pages; i++) {
1116                 ttm->pages[i] = NULL;
1117                 ttm_dma->dma_address[i] = 0;
1118         }
1119
1120         /* shrink pool if necessary (only on !is_cached pools)*/
1121         if (npages)
1122                 ttm_dma_page_pool_free(pool, npages, false);
1123         ttm->state = tt_unpopulated;
1124 }
1125 EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
1126
1127 /**
1128  * Callback for mm to request pool to reduce number of page held.
1129  *
1130  * XXX: (dchinner) Deadlock warning!
1131  *
1132  * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
1133  * shrinkers
1134  */
1135 static unsigned long
1136 ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1137 {
1138         static unsigned start_pool;
1139         unsigned idx = 0;
1140         unsigned pool_offset;
1141         unsigned shrink_pages = sc->nr_to_scan;
1142         struct device_pools *p;
1143         unsigned long freed = 0;
1144
1145         if (list_empty(&_manager->pools))
1146                 return SHRINK_STOP;
1147
1148         if (!mutex_trylock(&_manager->lock))
1149                 return SHRINK_STOP;
1150         if (!_manager->npools)
1151                 goto out;
1152         pool_offset = ++start_pool % _manager->npools;
1153         list_for_each_entry(p, &_manager->pools, pools) {
1154                 unsigned nr_free;
1155
1156                 if (!p->dev)
1157                         continue;
1158                 if (shrink_pages == 0)
1159                         break;
1160                 /* Do it in round-robin fashion. */
1161                 if (++idx < pool_offset)
1162                         continue;
1163                 nr_free = shrink_pages;
1164                 /* OK to use static buffer since global mutex is held. */
1165                 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free, true);
1166                 freed += nr_free - shrink_pages;
1167
1168                 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
1169                          p->pool->dev_name, p->pool->name, current->pid,
1170                          nr_free, shrink_pages);
1171         }
1172 out:
1173         mutex_unlock(&_manager->lock);
1174         return freed;
1175 }
1176
1177 static unsigned long
1178 ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
1179 {
1180         struct device_pools *p;
1181         unsigned long count = 0;
1182
1183         if (!mutex_trylock(&_manager->lock))
1184                 return 0;
1185         list_for_each_entry(p, &_manager->pools, pools)
1186                 count += p->pool->npages_free;
1187         mutex_unlock(&_manager->lock);
1188         return count;
1189 }
1190
1191 static int ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
1192 {
1193         manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count;
1194         manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
1195         manager->mm_shrink.seeks = 1;
1196         return register_shrinker(&manager->mm_shrink);
1197 }
1198
1199 static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
1200 {
1201         unregister_shrinker(&manager->mm_shrink);
1202 }
1203
1204 int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1205 {
1206         int ret;
1207
1208         WARN_ON(_manager);
1209
1210         pr_info("Initializing DMA pool allocator\n");
1211
1212         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1213         if (!_manager)
1214                 return -ENOMEM;
1215
1216         mutex_init(&_manager->lock);
1217         INIT_LIST_HEAD(&_manager->pools);
1218
1219         _manager->options.max_size = max_pages;
1220         _manager->options.small = SMALL_ALLOCATION;
1221         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1222
1223         /* This takes care of auto-freeing the _manager */
1224         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1225                                    &glob->kobj, "dma_pool");
1226         if (unlikely(ret != 0))
1227                 goto error;
1228
1229         ret = ttm_dma_pool_mm_shrink_init(_manager);
1230         if (unlikely(ret != 0))
1231                 goto error;
1232         return 0;
1233
1234 error:
1235         kobject_put(&_manager->kobj);
1236         _manager = NULL;
1237         return ret;
1238 }
1239
1240 void ttm_dma_page_alloc_fini(void)
1241 {
1242         struct device_pools *p, *t;
1243
1244         pr_info("Finalizing DMA pool allocator\n");
1245         ttm_dma_pool_mm_shrink_fini(_manager);
1246
1247         list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
1248                 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
1249                         current->pid);
1250                 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
1251                         ttm_dma_pool_match, p->pool));
1252                 ttm_dma_free_pool(p->dev, p->pool->type);
1253         }
1254         kobject_put(&_manager->kobj);
1255         _manager = NULL;
1256 }
1257
1258 int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
1259 {
1260         struct device_pools *p;
1261         struct dma_pool *pool = NULL;
1262
1263         if (!_manager) {
1264                 seq_printf(m, "No pool allocator running.\n");
1265                 return 0;
1266         }
1267         seq_printf(m, "         pool      refills   pages freed    inuse available     name\n");
1268         mutex_lock(&_manager->lock);
1269         list_for_each_entry(p, &_manager->pools, pools) {
1270                 struct device *dev = p->dev;
1271                 if (!dev)
1272                         continue;
1273                 pool = p->pool;
1274                 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
1275                                 pool->name, pool->nrefills,
1276                                 pool->nfrees, pool->npages_in_use,
1277                                 pool->npages_free,
1278                                 pool->dev_name);
1279         }
1280         mutex_unlock(&_manager->lock);
1281         return 0;
1282 }
1283 EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);
1284
1285 #endif