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
  57 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(struct page *))
  58 #define SMALL_ALLOCATION                4
  59 #define FREE_ALL_PAGES                  (~0U)
  60 /* times are in msecs */
  61 #define IS_UNDEFINED                    (0)
  62 #define IS_WC                           (1<<1)
  63 #define IS_UC                           (1<<2)
  64 #define IS_CACHED                       (1<<3)
  65 #define IS_DMA32                        (1<<4)
  66
  67 enum pool_type {
  68         POOL_IS_UNDEFINED,
  69         POOL_IS_WC = IS_WC,
  70         POOL_IS_UC = IS_UC,
  71         POOL_IS_CACHED = IS_CACHED,
  72         POOL_IS_WC_DMA32 = IS_WC | IS_DMA32,
  73         POOL_IS_UC_DMA32 = IS_UC | IS_DMA32,
  74         POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32,
  75 };
  76 /*
  77  * The pool structure. There are usually six pools:
  78  *  - generic (not restricted to DMA32):
  79  *      - write combined, uncached, cached.
  80  *  - dma32 (up to 2^32 - so up 4GB):
  81  *      - write combined, uncached, cached.
  82  * for each 'struct device'. The 'cached' is for pages that are actively used.
  83  * The other ones can be shrunk by the shrinker API if neccessary.
  84  * @pools: The 'struct device->dma_pools' link.
  85  * @type: Type of the pool
  86  * @lock: Protects the inuse_list and free_list from concurrnet access. Must be
  87  * used with irqsave/irqrestore variants because pool allocator maybe called
  88  * from delayed work.
  89  * @inuse_list: Pool of pages that are in use. The order is very important and
  90  *   it is in the order that the TTM pages that are put back are in.
  91  * @free_list: Pool of pages that are free to be used. No order requirements.
  92  * @dev: The device that is associated with these pools.
  93  * @size: Size used during DMA allocation.
  94  * @npages_free: Count of available pages for re-use.
  95  * @npages_in_use: Count of pages that are in use.
  96  * @nfrees: Stats when pool is shrinking.
  97  * @nrefills: Stats when the pool is grown.
  98  * @gfp_flags: Flags to pass for alloc_page.
  99  * @name: Name of the pool.
 100  * @dev_name: Name derieved from dev - similar to how dev_info works.
 101  *   Used during shutdown as the dev_info during release is unavailable.
 102  */
 103 struct dma_pool {
 104         struct list_head pools; /* The 'struct device->dma_pools link */
 105         enum pool_type type;
 106         spinlock_t lock;
 107         struct list_head inuse_list;
 108         struct list_head free_list;
 109         struct device *dev;
 110         unsigned size;
 111         unsigned npages_free;
 112         unsigned npages_in_use;
 113         unsigned long nfrees; /* Stats when shrunk. */
 114         unsigned long nrefills; /* Stats when grown. */
 115         gfp_t gfp_flags;
 116         char name[13]; /* "cached dma32" */
 117         char dev_name[64]; /* Constructed from dev */
 118 };
 119
 120 /*
 121  * The accounting page keeping track of the allocated page along with
 122  * the DMA address.
 123  * @page_list: The link to the 'page_list' in 'struct dma_pool'.
 124  * @vaddr: The virtual address of the page
 125  * @dma: The bus address of the page. If the page is not allocated
 126  *   via the DMA API, it will be -1.
 127  */
 128 struct dma_page {
 129         struct list_head page_list;
 130         void *vaddr;
 131         struct page *p;
 132         dma_addr_t dma;
 133 };
 134
 135 /*
 136  * Limits for the pool. They are handled without locks because only place where
 137  * they may change is in sysfs store. They won't have immediate effect anyway
 138  * so forcing serialization to access them is pointless.
 139  */
 140
 141 struct ttm_pool_opts {
 142         unsigned        alloc_size;
 143         unsigned        max_size;
 144         unsigned        small;
 145 };
 146
 147 /*
 148  * Contains the list of all of the 'struct device' and their corresponding
 149  * DMA pools. Guarded by _mutex->lock.
 150  * @pools: The link to 'struct ttm_pool_manager->pools'
 151  * @dev: The 'struct device' associated with the 'pool'
 152  * @pool: The 'struct dma_pool' associated with the 'dev'
 153  */
 154 struct device_pools {
 155         struct list_head pools;
 156         struct device *dev;
 157         struct dma_pool *pool;
 158 };
 159
 160 /*
 161  * struct ttm_pool_manager - Holds memory pools for fast allocation
 162  *
 163  * @lock: Lock used when adding/removing from pools
 164  * @pools: List of 'struct device' and 'struct dma_pool' tuples.
 165  * @options: Limits for the pool.
 166  * @npools: Total amount of pools in existence.
 167  * @shrinker: The structure used by [un|]register_shrinker
 168  */
 169 struct ttm_pool_manager {
 170         struct mutex            lock;
 171         struct list_head        pools;
 172         struct ttm_pool_opts    options;
 173         unsigned                npools;
 174         struct shrinker         mm_shrink;
 175         struct kobject          kobj;
 176 };
 177
 178 static struct ttm_pool_manager *_manager;
 179
 180 static struct attribute ttm_page_pool_max = {
 181         .name = "pool_max_size",
 182         .mode = S_IRUGO | S_IWUSR
 183 };
 184 static struct attribute ttm_page_pool_small = {
 185         .name = "pool_small_allocation",
 186         .mode = S_IRUGO | S_IWUSR
 187 };
 188 static struct attribute ttm_page_pool_alloc_size = {
 189         .name = "pool_allocation_size",
 190         .mode = S_IRUGO | S_IWUSR
 191 };
 192
 193 static struct attribute *ttm_pool_attrs[] = {
 194         &ttm_page_pool_max,
 195         &ttm_page_pool_small,
 196         &ttm_page_pool_alloc_size,
 197         NULL
 198 };
 199
 200 static void ttm_pool_kobj_release(struct kobject *kobj)
 201 {
 202         struct ttm_pool_manager *m =
 203                 container_of(kobj, struct ttm_pool_manager, kobj);
 204         kfree(m);
 205 }
 206
 207 static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
 208                               const char *buffer, size_t size)
 209 {
 210         struct ttm_pool_manager *m =
 211                 container_of(kobj, struct ttm_pool_manager, kobj);
 212         int chars;
 213         unsigned val;
 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         dma_free_coherent(pool->dev, pool->size, 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
 338         d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
 339         if (!d_page)
 340                 return NULL;
 341
 342         d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
 343                                            &d_page->dma,
 344                                            pool->gfp_flags);
 345         if (d_page->vaddr) {
 346                 if (is_vmalloc_addr(d_page->vaddr))
 347                         d_page->p = vmalloc_to_page(d_page->vaddr);
 348                 else
 349                         d_page->p = virt_to_page(d_page->vaddr);
 350         } else {
 351                 kfree(d_page);
 352                 d_page = NULL;
 353         }
 354         return d_page;
 355 }
 356 static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
 357 {
 358         enum pool_type type = IS_UNDEFINED;
 359
 360         if (flags & TTM_PAGE_FLAG_DMA32)
 361                 type |= IS_DMA32;
 362         if (cstate == tt_cached)
 363                 type |= IS_CACHED;
 364         else if (cstate == tt_uncached)
 365                 type |= IS_UC;
 366         else
 367                 type |= IS_WC;
 368
 369         return type;
 370 }
 371
 372 static void ttm_pool_update_free_locked(struct dma_pool *pool,
 373                                         unsigned freed_pages)
 374 {
 375         pool->npages_free -= freed_pages;
 376         pool->nfrees += freed_pages;
 377
 378 }
 379
 380 /* set memory back to wb and free the pages. */
 381 static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
 382                               struct page *pages[], unsigned npages)
 383 {
 384         struct dma_page *d_page, *tmp;
 385
 386         /* Don't set WB on WB page pool. */
 387         if (npages && !(pool->type & IS_CACHED) &&
 388             set_pages_array_wb(pages, npages))
 389                 pr_err("%s: Failed to set %d pages to wb!\n",
 390                        pool->dev_name, npages);
 391
 392         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 393                 list_del(&d_page->page_list);
 394                 __ttm_dma_free_page(pool, d_page);
 395         }
 396 }
 397
 398 static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
 399 {
 400         /* Don't set WB on WB page pool. */
 401         if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1))
 402                 pr_err("%s: Failed to set %d pages to wb!\n",
 403                        pool->dev_name, 1);
 404
 405         list_del(&d_page->page_list);
 406         __ttm_dma_free_page(pool, d_page);
 407 }
 408
 409 /*
 410  * Free pages from pool.
 411  *
 412  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 413  * number of pages in one go.
 414  *
 415  * @pool: to free the pages from
 416  * @nr_free: If set to true will free all pages in pool
 417  * @use_static: Safe to use static buffer
 418  **/
 419 static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
 420                                        bool use_static)
 421 {
 422         static struct page *static_buf[NUM_PAGES_TO_ALLOC];
 423         unsigned long irq_flags;
 424         struct dma_page *dma_p, *tmp;
 425         struct page **pages_to_free;
 426         struct list_head d_pages;
 427         unsigned freed_pages = 0,
 428                  npages_to_free = nr_free;
 429
 430         if (NUM_PAGES_TO_ALLOC < nr_free)
 431                 npages_to_free = NUM_PAGES_TO_ALLOC;
 432 #if 0
 433         if (nr_free > 1) {
 434                 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
 435                          pool->dev_name, pool->name, current->pid,
 436                          npages_to_free, nr_free);
 437         }
 438 #endif
 439         if (use_static)
 440                 pages_to_free = static_buf;
 441         else
 442                 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 443                                         GFP_KERNEL);
 444
 445         if (!pages_to_free) {
 446                 pr_err("%s: Failed to allocate memory for pool free operation\n",
 447                        pool->dev_name);
 448                 return 0;
 449         }
 450         INIT_LIST_HEAD(&d_pages);
 451 restart:
 452         spin_lock_irqsave(&pool->lock, irq_flags);
 453
 454         /* We picking the oldest ones off the list */
 455         list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
 456                                          page_list) {
 457                 if (freed_pages >= npages_to_free)
 458                         break;
 459
 460                 /* Move the dma_page from one list to another. */
 461                 list_move(&dma_p->page_list, &d_pages);
 462
 463                 pages_to_free[freed_pages++] = dma_p->p;
 464                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 465                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 466
 467                         ttm_pool_update_free_locked(pool, freed_pages);
 468                         /**
 469                          * Because changing page caching is costly
 470                          * we unlock the pool to prevent stalling.
 471                          */
 472                         spin_unlock_irqrestore(&pool->lock, irq_flags);
 473
 474                         ttm_dma_pages_put(pool, &d_pages, pages_to_free,
 475                                           freed_pages);
 476
 477                         INIT_LIST_HEAD(&d_pages);
 478
 479                         if (likely(nr_free != FREE_ALL_PAGES))
 480                                 nr_free -= freed_pages;
 481
 482                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 483                                 npages_to_free = nr_free;
 484                         else
 485                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 486
 487                         freed_pages = 0;
 488
 489                         /* free all so restart the processing */
 490                         if (nr_free)
 491                                 goto restart;
 492
 493                         /* Not allowed to fall through or break because
 494                          * following context is inside spinlock while we are
 495                          * outside here.
 496                          */
 497                         goto out;
 498
 499                 }
 500         }
 501
 502         /* remove range of pages from the pool */
 503         if (freed_pages) {
 504                 ttm_pool_update_free_locked(pool, freed_pages);
 505                 nr_free -= freed_pages;
 506         }
 507
 508         spin_unlock_irqrestore(&pool->lock, irq_flags);
 509
 510         if (freed_pages)
 511                 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
 512 out:
 513         if (pages_to_free != static_buf)
 514                 kfree(pages_to_free);
 515         return nr_free;
 516 }
 517
 518 static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
 519 {
 520         struct device_pools *p;
 521         struct dma_pool *pool;
 522
 523         if (!dev)
 524                 return;
 525
 526         mutex_lock(&_manager->lock);
 527         list_for_each_entry_reverse(p, &_manager->pools, pools) {
 528                 if (p->dev != dev)
 529                         continue;
 530                 pool = p->pool;
 531                 if (pool->type != type)
 532                         continue;
 533
 534                 list_del(&p->pools);
 535                 kfree(p);
 536                 _manager->npools--;
 537                 break;
 538         }
 539         list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
 540                 if (pool->type != type)
 541                         continue;
 542                 /* Takes a spinlock.. */
 543                 /* OK to use static buffer since global mutex is held. */
 544                 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, true);
 545                 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
 546                 /* This code path is called after _all_ references to the
 547                  * struct device has been dropped - so nobody should be
 548                  * touching it. In case somebody is trying to _add_ we are
 549                  * guarded by the mutex. */
 550                 list_del(&pool->pools);
 551                 kfree(pool);
 552                 break;
 553         }
 554         mutex_unlock(&_manager->lock);
 555 }
 556
 557 /*
 558  * On free-ing of the 'struct device' this deconstructor is run.
 559  * Albeit the pool might have already been freed earlier.
 560  */
 561 static void ttm_dma_pool_release(struct device *dev, void *res)
 562 {
 563         struct dma_pool *pool = *(struct dma_pool **)res;
 564
 565         if (pool)
 566                 ttm_dma_free_pool(dev, pool->type);
 567 }
 568
 569 static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
 570 {
 571         return *(struct dma_pool **)res == match_data;
 572 }
 573
 574 static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
 575                                           enum pool_type type)
 576 {
 577         char *n[] = {"wc", "uc", "cached", " dma32", "unknown",};
 578         enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED};
 579         struct device_pools *sec_pool = NULL;
 580         struct dma_pool *pool = NULL, **ptr;
 581         unsigned i;
 582         int ret = -ENODEV;
 583         char *p;
 584
 585         if (!dev)
 586                 return NULL;
 587
 588         ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
 589         if (!ptr)
 590                 return NULL;
 591
 592         ret = -ENOMEM;
 593
 594         pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
 595                             dev_to_node(dev));
 596         if (!pool)
 597                 goto err_mem;
 598
 599         sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
 600                                 dev_to_node(dev));
 601         if (!sec_pool)
 602                 goto err_mem;
 603
 604         INIT_LIST_HEAD(&sec_pool->pools);
 605         sec_pool->dev = dev;
 606         sec_pool->pool =  pool;
 607
 608         INIT_LIST_HEAD(&pool->free_list);
 609         INIT_LIST_HEAD(&pool->inuse_list);
 610         INIT_LIST_HEAD(&pool->pools);
 611         spin_lock_init(&pool->lock);
 612         pool->dev = dev;
 613         pool->npages_free = pool->npages_in_use = 0;
 614         pool->nfrees = 0;
 615         pool->gfp_flags = flags;
 616         pool->size = PAGE_SIZE;
 617         pool->type = type;
 618         pool->nrefills = 0;
 619         p = pool->name;
 620         for (i = 0; i < 5; i++) {
 621                 if (type & t[i]) {
 622                         p += snprintf(p, sizeof(pool->name) - (p - pool->name),
 623                                       "%s", n[i]);
 624                 }
 625         }
 626         *p = 0;
 627         /* We copy the name for pr_ calls b/c when dma_pool_destroy is called
 628          * - the kobj->name has already been deallocated.*/
 629         snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
 630                  dev_driver_string(dev), dev_name(dev));
 631         mutex_lock(&_manager->lock);
 632         /* You can get the dma_pool from either the global: */
 633         list_add(&sec_pool->pools, &_manager->pools);
 634         _manager->npools++;
 635         /* or from 'struct device': */
 636         list_add(&pool->pools, &dev->dma_pools);
 637         mutex_unlock(&_manager->lock);
 638
 639         *ptr = pool;
 640         devres_add(dev, ptr);
 641
 642         return pool;
 643 err_mem:
 644         devres_free(ptr);
 645         kfree(sec_pool);
 646         kfree(pool);
 647         return ERR_PTR(ret);
 648 }
 649
 650 static struct dma_pool *ttm_dma_find_pool(struct device *dev,
 651                                           enum pool_type type)
 652 {
 653         struct dma_pool *pool, *tmp, *found = NULL;
 654
 655         if (type == IS_UNDEFINED)
 656                 return found;
 657
 658         /* NB: We iterate on the 'struct dev' which has no spinlock, but
 659          * it does have a kref which we have taken. The kref is taken during
 660          * graphic driver loading - in the drm_pci_init it calls either
 661          * pci_dev_get or pci_register_driver which both end up taking a kref
 662          * on 'struct device'.
 663          *
 664          * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
 665          * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
 666          * thing is at that point of time there are no pages associated with the
 667          * driver so this function will not be called.
 668          */
 669         list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) {
 670                 if (pool->type != type)
 671                         continue;
 672                 found = pool;
 673                 break;
 674         }
 675         return found;
 676 }
 677
 678 /*
 679  * Free pages the pages that failed to change the caching state. If there
 680  * are pages that have changed their caching state already put them to the
 681  * pool.
 682  */
 683 static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
 684                                                  struct list_head *d_pages,
 685                                                  struct page **failed_pages,
 686                                                  unsigned cpages)
 687 {
 688         struct dma_page *d_page, *tmp;
 689         struct page *p;
 690         unsigned i = 0;
 691
 692         p = failed_pages[0];
 693         if (!p)
 694                 return;
 695         /* Find the failed page. */
 696         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 697                 if (d_page->p != p)
 698                         continue;
 699                 /* .. and then progress over the full list. */
 700                 list_del(&d_page->page_list);
 701                 __ttm_dma_free_page(pool, d_page);
 702                 if (++i < cpages)
 703                         p = failed_pages[i];
 704                 else
 705                         break;
 706         }
 707
 708 }
 709
 710 /*
 711  * Allocate 'count' pages, and put 'need' number of them on the
 712  * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
 713  * The full list of pages should also be on 'd_pages'.
 714  * We return zero for success, and negative numbers as errors.
 715  */
 716 static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
 717                                         struct list_head *d_pages,
 718                                         unsigned count)
 719 {
 720         struct page **caching_array;
 721         struct dma_page *dma_p;
 722         struct page *p;
 723         int r = 0;
 724         unsigned i, cpages;
 725         unsigned max_cpages = min(count,
 726                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 727
 728         /* allocate array for page caching change */
 729         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 730
 731         if (!caching_array) {
 732                 pr_err("%s: Unable to allocate table for new pages\n",
 733                        pool->dev_name);
 734                 return -ENOMEM;
 735         }
 736
 737         if (count > 1) {
 738                 pr_debug("%s: (%s:%d) Getting %d pages\n",
 739                          pool->dev_name, pool->name, current->pid, count);
 740         }
 741
 742         for (i = 0, cpages = 0; i < count; ++i) {
 743                 dma_p = __ttm_dma_alloc_page(pool);
 744                 if (!dma_p) {
 745                         pr_err("%s: Unable to get page %u\n",
 746                                pool->dev_name, i);
 747
 748                         /* store already allocated pages in the pool after
 749                          * setting the caching state */
 750                         if (cpages) {
 751                                 r = ttm_set_pages_caching(pool, caching_array,
 752                                                           cpages);
 753                                 if (r)
 754                                         ttm_dma_handle_caching_state_failure(
 755                                                 pool, d_pages, caching_array,
 756                                                 cpages);
 757                         }
 758                         r = -ENOMEM;
 759                         goto out;
 760                 }
 761                 p = dma_p->p;
 762 #ifdef CONFIG_HIGHMEM
 763                 /* gfp flags of highmem page should never be dma32 so we
 764                  * we should be fine in such case
 765                  */
 766                 if (!PageHighMem(p))
 767 #endif
 768                 {
 769                         caching_array[cpages++] = p;
 770                         if (cpages == max_cpages) {
 771                                 /* Note: Cannot hold the spinlock */
 772                                 r = ttm_set_pages_caching(pool, caching_array,
 773                                                  cpages);
 774                                 if (r) {
 775                                         ttm_dma_handle_caching_state_failure(
 776                                                 pool, d_pages, caching_array,
 777                                                 cpages);
 778                                         goto out;
 779                                 }
 780                                 cpages = 0;
 781                         }
 782                 }
 783                 list_add(&dma_p->page_list, d_pages);
 784         }
 785
 786         if (cpages) {
 787                 r = ttm_set_pages_caching(pool, caching_array, cpages);
 788                 if (r)
 789                         ttm_dma_handle_caching_state_failure(pool, d_pages,
 790                                         caching_array, cpages);
 791         }
 792 out:
 793         kfree(caching_array);
 794         return r;
 795 }
 796
 797 /*
 798  * @return count of pages still required to fulfill the request.
 799  */
 800 static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
 801                                          unsigned long *irq_flags)
 802 {
 803         unsigned count = _manager->options.small;
 804         int r = pool->npages_free;
 805
 806         if (count > pool->npages_free) {
 807                 struct list_head d_pages;
 808
 809                 INIT_LIST_HEAD(&d_pages);
 810
 811                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 812
 813                 /* Returns how many more are neccessary to fulfill the
 814                  * request. */
 815                 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
 816
 817                 spin_lock_irqsave(&pool->lock, *irq_flags);
 818                 if (!r) {
 819                         /* Add the fresh to the end.. */
 820                         list_splice(&d_pages, &pool->free_list);
 821                         ++pool->nrefills;
 822                         pool->npages_free += count;
 823                         r = count;
 824                 } else {
 825                         struct dma_page *d_page;
 826                         unsigned cpages = 0;
 827
 828                         pr_err("%s: Failed to fill %s pool (r:%d)!\n",
 829                                pool->dev_name, pool->name, r);
 830
 831                         list_for_each_entry(d_page, &d_pages, page_list) {
 832                                 cpages++;
 833                         }
 834                         list_splice_tail(&d_pages, &pool->free_list);
 835                         pool->npages_free += cpages;
 836                         r = cpages;
 837                 }
 838         }
 839         return r;
 840 }
 841
 842 /*
 843  * @return count of pages still required to fulfill the request.
 844  * The populate list is actually a stack (not that is matters as TTM
 845  * allocates one page at a time.
 846  */
 847 static int ttm_dma_pool_get_pages(struct dma_pool *pool,
 848                                   struct ttm_dma_tt *ttm_dma,
 849                                   unsigned index)
 850 {
 851         struct dma_page *d_page;
 852         struct ttm_tt *ttm = &ttm_dma->ttm;
 853         unsigned long irq_flags;
 854         int count, r = -ENOMEM;
 855
 856         spin_lock_irqsave(&pool->lock, irq_flags);
 857         count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
 858         if (count) {
 859                 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
 860                 ttm->pages[index] = d_page->p;
 861                 ttm_dma->dma_address[index] = d_page->dma;
 862                 list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
 863                 r = 0;
 864                 pool->npages_in_use += 1;
 865                 pool->npages_free -= 1;
 866         }
 867         spin_unlock_irqrestore(&pool->lock, irq_flags);
 868         return r;
 869 }
 870
 871 /*
 872  * On success pages list will hold count number of correctly
 873  * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
 874  */
 875 int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 876 {
 877         struct ttm_tt *ttm = &ttm_dma->ttm;
 878         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 879         struct dma_pool *pool;
 880         enum pool_type type;
 881         unsigned i;
 882         gfp_t gfp_flags;
 883         int ret;
 884
 885         if (ttm->state != tt_unpopulated)
 886                 return 0;
 887
 888         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 889         if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 890                 gfp_flags = GFP_USER | GFP_DMA32;
 891         else
 892                 gfp_flags = GFP_HIGHUSER;
 893         if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 894                 gfp_flags |= __GFP_ZERO;
 895
 896         pool = ttm_dma_find_pool(dev, type);
 897         if (!pool) {
 898                 pool = ttm_dma_pool_init(dev, gfp_flags, type);
 899                 if (IS_ERR_OR_NULL(pool)) {
 900                         return -ENOMEM;
 901                 }
 902         }
 903
 904         INIT_LIST_HEAD(&ttm_dma->pages_list);
 905         for (i = 0; i < ttm->num_pages; ++i) {
 906                 ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
 907                 if (ret != 0) {
 908                         ttm_dma_unpopulate(ttm_dma, dev);
 909                         return -ENOMEM;
 910                 }
 911
 912                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 913                                                 false, false);
 914                 if (unlikely(ret != 0)) {
 915                         ttm_dma_unpopulate(ttm_dma, dev);
 916                         return -ENOMEM;
 917                 }
 918         }
 919
 920         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 921                 ret = ttm_tt_swapin(ttm);
 922                 if (unlikely(ret != 0)) {
 923                         ttm_dma_unpopulate(ttm_dma, dev);
 924                         return ret;
 925                 }
 926         }
 927
 928         ttm->state = tt_unbound;
 929         return 0;
 930 }
 931 EXPORT_SYMBOL_GPL(ttm_dma_populate);
 932
 933 /* Put all pages in pages list to correct pool to wait for reuse */
 934 void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 935 {
 936         struct ttm_tt *ttm = &ttm_dma->ttm;
 937         struct dma_pool *pool;
 938         struct dma_page *d_page, *next;
 939         enum pool_type type;
 940         bool is_cached = false;
 941         unsigned count = 0, i, npages = 0;
 942         unsigned long irq_flags;
 943
 944         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 945         pool = ttm_dma_find_pool(dev, type);
 946         if (!pool)
 947                 return;
 948
 949         is_cached = (ttm_dma_find_pool(pool->dev,
 950                      ttm_to_type(ttm->page_flags, tt_cached)) == pool);
 951
 952         /* make sure pages array match list and count number of pages */
 953         list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) {
 954                 ttm->pages[count] = d_page->p;
 955                 count++;
 956         }
 957
 958         spin_lock_irqsave(&pool->lock, irq_flags);
 959         pool->npages_in_use -= count;
 960         if (is_cached) {
 961                 pool->nfrees += count;
 962         } else {
 963                 pool->npages_free += count;
 964                 list_splice(&ttm_dma->pages_list, &pool->free_list);
 965                 /*
 966                  * Wait to have at at least NUM_PAGES_TO_ALLOC number of pages
 967                  * to free in order to minimize calls to set_memory_wb().
 968                  */
 969                 if (pool->npages_free >= (_manager->options.max_size +
 970                                           NUM_PAGES_TO_ALLOC))
 971                         npages = pool->npages_free - _manager->options.max_size;
 972         }
 973         spin_unlock_irqrestore(&pool->lock, irq_flags);
 974
 975         if (is_cached) {
 976                 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) {
 977                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 978                                                  d_page->p);
 979                         ttm_dma_page_put(pool, d_page);
 980                 }
 981         } else {
 982                 for (i = 0; i < count; i++) {
 983                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 984                                                  ttm->pages[i]);
 985                 }
 986         }
 987
 988         INIT_LIST_HEAD(&ttm_dma->pages_list);
 989         for (i = 0; i < ttm->num_pages; i++) {
 990                 ttm->pages[i] = NULL;
 991                 ttm_dma->dma_address[i] = 0;
 992         }
 993
 994         /* shrink pool if necessary (only on !is_cached pools)*/
 995         if (npages)
 996                 ttm_dma_page_pool_free(pool, npages, false);
 997         ttm->state = tt_unpopulated;
 998 }
 999 EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
1000
1001 /**
1002  * Callback for mm to request pool to reduce number of page held.
1003  *
1004  * XXX: (dchinner) Deadlock warning!
1005  *
1006  * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
1007  * shrinkers
1008  */
1009 static unsigned long
1010 ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1011 {
1012         static unsigned start_pool;
1013         unsigned idx = 0;
1014         unsigned pool_offset;
1015         unsigned shrink_pages = sc->nr_to_scan;
1016         struct device_pools *p;
1017         unsigned long freed = 0;
1018
1019         if (list_empty(&_manager->pools))
1020                 return SHRINK_STOP;
1021
1022         if (!mutex_trylock(&_manager->lock))
1023                 return SHRINK_STOP;
1024         if (!_manager->npools)
1025                 goto out;
1026         pool_offset = ++start_pool % _manager->npools;
1027         list_for_each_entry(p, &_manager->pools, pools) {
1028                 unsigned nr_free;
1029
1030                 if (!p->dev)
1031                         continue;
1032                 if (shrink_pages == 0)
1033                         break;
1034                 /* Do it in round-robin fashion. */
1035                 if (++idx < pool_offset)
1036                         continue;
1037                 nr_free = shrink_pages;
1038                 /* OK to use static buffer since global mutex is held. */
1039                 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free, true);
1040                 freed += nr_free - shrink_pages;
1041
1042                 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
1043                          p->pool->dev_name, p->pool->name, current->pid,
1044                          nr_free, shrink_pages);
1045         }
1046 out:
1047         mutex_unlock(&_manager->lock);
1048         return freed;
1049 }
1050
1051 static unsigned long
1052 ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
1053 {
1054         struct device_pools *p;
1055         unsigned long count = 0;
1056
1057         if (!mutex_trylock(&_manager->lock))
1058                 return 0;
1059         list_for_each_entry(p, &_manager->pools, pools)
1060                 count += p->pool->npages_free;
1061         mutex_unlock(&_manager->lock);
1062         return count;
1063 }
1064
1065 static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
1066 {
1067         manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count;
1068         manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
1069         manager->mm_shrink.seeks = 1;
1070         register_shrinker(&manager->mm_shrink);
1071 }
1072
1073 static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
1074 {
1075         unregister_shrinker(&manager->mm_shrink);
1076 }
1077
1078 int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1079 {
1080         int ret = -ENOMEM;
1081
1082         WARN_ON(_manager);
1083
1084         pr_info("Initializing DMA pool allocator\n");
1085
1086         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1087         if (!_manager)
1088                 goto err;
1089
1090         mutex_init(&_manager->lock);
1091         INIT_LIST_HEAD(&_manager->pools);
1092
1093         _manager->options.max_size = max_pages;
1094         _manager->options.small = SMALL_ALLOCATION;
1095         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1096
1097         /* This takes care of auto-freeing the _manager */
1098         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1099                                    &glob->kobj, "dma_pool");
1100         if (unlikely(ret != 0)) {
1101                 kobject_put(&_manager->kobj);
1102                 goto err;
1103         }
1104         ttm_dma_pool_mm_shrink_init(_manager);
1105         return 0;
1106 err:
1107         return ret;
1108 }
1109
1110 void ttm_dma_page_alloc_fini(void)
1111 {
1112         struct device_pools *p, *t;
1113
1114         pr_info("Finalizing DMA pool allocator\n");
1115         ttm_dma_pool_mm_shrink_fini(_manager);
1116
1117         list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
1118                 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
1119                         current->pid);
1120                 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
1121                         ttm_dma_pool_match, p->pool));
1122                 ttm_dma_free_pool(p->dev, p->pool->type);
1123         }
1124         kobject_put(&_manager->kobj);
1125         _manager = NULL;
1126 }
1127
1128 int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
1129 {
1130         struct device_pools *p;
1131         struct dma_pool *pool = NULL;
1132         char *h[] = {"pool", "refills", "pages freed", "inuse", "available",
1133                      "name", "virt", "busaddr"};
1134
1135         if (!_manager) {
1136                 seq_printf(m, "No pool allocator running.\n");
1137                 return 0;
1138         }
1139         seq_printf(m, "%13s %12s %13s %8s %8s %8s\n",
1140                    h[0], h[1], h[2], h[3], h[4], h[5]);
1141         mutex_lock(&_manager->lock);
1142         list_for_each_entry(p, &_manager->pools, pools) {
1143                 struct device *dev = p->dev;
1144                 if (!dev)
1145                         continue;
1146                 pool = p->pool;
1147                 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
1148                                 pool->name, pool->nrefills,
1149                                 pool->nfrees, pool->npages_in_use,
1150                                 pool->npages_free,
1151                                 pool->dev_name);
1152         }
1153         mutex_unlock(&_manager->lock);
1154         return 0;
1155 }
1156 EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);
1157
1158 #endif