sys/dev/drm2/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 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38
  39 #define pr_fmt(fmt) "[TTM] " fmt
  40
  41 #include <linux/dma-mapping.h>
  42 #include <linux/list.h>
  43 #include <linux/seq_file.h> /* for seq_printf */
  44 #include <linux/slab.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/highmem.h>
  47 #include <linux/mm_types.h>
  48 #include <linux/module.h>
  49 #include <linux/mm.h>
  50 #include <linux/atomic.h>
  51 #include <linux/device.h>
  52 #include <linux/kthread.h>
  53 #include <drm/ttm/ttm_bo_driver.h>
  54 #include <drm/ttm/ttm_page_alloc.h>
  55 #ifdef TTM_HAS_AGP
  56 #include <asm/agp.h>
  57 #endif
  58
  59 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(struct page *))
  60 #define SMALL_ALLOCATION                4
  61 #define FREE_ALL_PAGES                  (~0U)
  62 /* times are in msecs */
  63 #define IS_UNDEFINED                    (0)
  64 #define IS_WC                           (1<<1)
  65 #define IS_UC                           (1<<2)
  66 #define IS_CACHED                       (1<<3)
  67 #define IS_DMA32                        (1<<4)
  68
  69 enum pool_type {
  70         POOL_IS_UNDEFINED,
  71         POOL_IS_WC = IS_WC,
  72         POOL_IS_UC = IS_UC,
  73         POOL_IS_CACHED = IS_CACHED,
  74         POOL_IS_WC_DMA32 = IS_WC | IS_DMA32,
  75         POOL_IS_UC_DMA32 = IS_UC | IS_DMA32,
  76         POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32,
  77 };
  78 /*
  79  * The pool structure. There are usually six pools:
  80  *  - generic (not restricted to DMA32):
  81  *      - write combined, uncached, cached.
  82  *  - dma32 (up to 2^32 - so up 4GB):
  83  *      - write combined, uncached, cached.
  84  * for each 'struct device'. The 'cached' is for pages that are actively used.
  85  * The other ones can be shrunk by the shrinker API if neccessary.
  86  * @pools: The 'struct device->dma_pools' link.
  87  * @type: Type of the pool
  88  * @lock: Protects the inuse_list and free_list from concurrnet access. Must be
  89  * used with irqsave/irqrestore variants because pool allocator maybe called
  90  * from delayed work.
  91  * @inuse_list: Pool of pages that are in use. The order is very important and
  92  *   it is in the order that the TTM pages that are put back are in.
  93  * @free_list: Pool of pages that are free to be used. No order requirements.
  94  * @dev: The device that is associated with these pools.
  95  * @size: Size used during DMA allocation.
  96  * @npages_free: Count of available pages for re-use.
  97  * @npages_in_use: Count of pages that are in use.
  98  * @nfrees: Stats when pool is shrinking.
  99  * @nrefills: Stats when the pool is grown.
 100  * @gfp_flags: Flags to pass for alloc_page.
 101  * @name: Name of the pool.
 102  * @dev_name: Name derieved from dev - similar to how dev_info works.
 103  *   Used during shutdown as the dev_info during release is unavailable.
 104  */
 105 struct dma_pool {
 106         struct list_head pools; /* The 'struct device->dma_pools link */
 107         enum pool_type type;
 108         spinlock_t lock;
 109         struct list_head inuse_list;
 110         struct list_head free_list;
 111         struct device *dev;
 112         unsigned size;
 113         unsigned npages_free;
 114         unsigned npages_in_use;
 115         unsigned long nfrees; /* Stats when shrunk. */
 116         unsigned long nrefills; /* Stats when grown. */
 117         gfp_t gfp_flags;
 118         char name[13]; /* "cached dma32" */
 119         char dev_name[64]; /* Constructed from dev */
 120 };
 121
 122 /*
 123  * The accounting page keeping track of the allocated page along with
 124  * the DMA address.
 125  * @page_list: The link to the 'page_list' in 'struct dma_pool'.
 126  * @vaddr: The virtual address of the page
 127  * @dma: The bus address of the page. If the page is not allocated
 128  *   via the DMA API, it will be -1.
 129  */
 130 struct dma_page {
 131         struct list_head page_list;
 132         void *vaddr;
 133         struct page *p;
 134         dma_addr_t dma;
 135 };
 136
 137 /*
 138  * Limits for the pool. They are handled without locks because only place where
 139  * they may change is in sysfs store. They won't have immediate effect anyway
 140  * so forcing serialization to access them is pointless.
 141  */
 142
 143 struct ttm_pool_opts {
 144         unsigned        alloc_size;
 145         unsigned        max_size;
 146         unsigned        small;
 147 };
 148
 149 /*
 150  * Contains the list of all of the 'struct device' and their corresponding
 151  * DMA pools. Guarded by _mutex->lock.
 152  * @pools: The link to 'struct ttm_pool_manager->pools'
 153  * @dev: The 'struct device' associated with the 'pool'
 154  * @pool: The 'struct dma_pool' associated with the 'dev'
 155  */
 156 struct device_pools {
 157         struct list_head pools;
 158         struct device *dev;
 159         struct dma_pool *pool;
 160 };
 161
 162 /*
 163  * struct ttm_pool_manager - Holds memory pools for fast allocation
 164  *
 165  * @lock: Lock used when adding/removing from pools
 166  * @pools: List of 'struct device' and 'struct dma_pool' tuples.
 167  * @options: Limits for the pool.
 168  * @npools: Total amount of pools in existence.
 169  * @shrinker: The structure used by [un|]register_shrinker
 170  */
 171 struct ttm_pool_manager {
 172         struct mutex            lock;
 173         struct list_head        pools;
 174         struct ttm_pool_opts    options;
 175         unsigned                npools;
 176         struct shrinker         mm_shrink;
 177         struct kobject          kobj;
 178 };
 179
 180 static struct ttm_pool_manager *_manager;
 181
 182 static struct attribute ttm_page_pool_max = {
 183         .name = "pool_max_size",
 184         .mode = S_IRUGO | S_IWUSR
 185 };
 186 static struct attribute ttm_page_pool_small = {
 187         .name = "pool_small_allocation",
 188         .mode = S_IRUGO | S_IWUSR
 189 };
 190 static struct attribute ttm_page_pool_alloc_size = {
 191         .name = "pool_allocation_size",
 192         .mode = S_IRUGO | S_IWUSR
 193 };
 194
 195 static struct attribute *ttm_pool_attrs[] = {
 196         &ttm_page_pool_max,
 197         &ttm_page_pool_small,
 198         &ttm_page_pool_alloc_size,
 199         NULL
 200 };
 201
 202 static void ttm_pool_kobj_release(struct kobject *kobj)
 203 {
 204         struct ttm_pool_manager *m =
 205                 container_of(kobj, struct ttm_pool_manager, kobj);
 206         kfree(m);
 207 }
 208
 209 static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
 210                               const char *buffer, size_t size)
 211 {
 212         struct ttm_pool_manager *m =
 213                 container_of(kobj, struct ttm_pool_manager, kobj);
 214         int chars;
 215         unsigned val;
 216         chars = sscanf(buffer, "%u", &val);
 217         if (chars == 0)
 218                 return size;
 219
 220         /* Convert kb to number of pages */
 221         val = val / (PAGE_SIZE >> 10);
 222
 223         if (attr == &ttm_page_pool_max)
 224                 m->options.max_size = val;
 225         else if (attr == &ttm_page_pool_small)
 226                 m->options.small = val;
 227         else if (attr == &ttm_page_pool_alloc_size) {
 228                 if (val > NUM_PAGES_TO_ALLOC*8) {
 229                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 230                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 231                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 232                         return size;
 233                 } else if (val > NUM_PAGES_TO_ALLOC) {
 234                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 235                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 236                 }
 237                 m->options.alloc_size = val;
 238         }
 239
 240         return size;
 241 }
 242
 243 static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
 244                              char *buffer)
 245 {
 246         struct ttm_pool_manager *m =
 247                 container_of(kobj, struct ttm_pool_manager, kobj);
 248         unsigned val = 0;
 249
 250         if (attr == &ttm_page_pool_max)
 251                 val = m->options.max_size;
 252         else if (attr == &ttm_page_pool_small)
 253                 val = m->options.small;
 254         else if (attr == &ttm_page_pool_alloc_size)
 255                 val = m->options.alloc_size;
 256
 257         val = val * (PAGE_SIZE >> 10);
 258
 259         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 260 }
 261
 262 static const struct sysfs_ops ttm_pool_sysfs_ops = {
 263         .show = &ttm_pool_show,
 264         .store = &ttm_pool_store,
 265 };
 266
 267 static struct kobj_type ttm_pool_kobj_type = {
 268         .release = &ttm_pool_kobj_release,
 269         .sysfs_ops = &ttm_pool_sysfs_ops,
 270         .default_attrs = ttm_pool_attrs,
 271 };
 272
 273 #ifndef CONFIG_X86
 274 static int set_pages_array_wb(struct page **pages, int addrinarray)
 275 {
 276 #ifdef TTM_HAS_AGP
 277         int i;
 278
 279         for (i = 0; i < addrinarray; i++)
 280                 unmap_page_from_agp(pages[i]);
 281 #endif
 282         return 0;
 283 }
 284
 285 static int set_pages_array_wc(struct page **pages, int addrinarray)
 286 {
 287 #ifdef TTM_HAS_AGP
 288         int i;
 289
 290         for (i = 0; i < addrinarray; i++)
 291                 map_page_into_agp(pages[i]);
 292 #endif
 293         return 0;
 294 }
 295
 296 static int set_pages_array_uc(struct page **pages, int addrinarray)
 297 {
 298 #ifdef TTM_HAS_AGP
 299         int i;
 300
 301         for (i = 0; i < addrinarray; i++)
 302                 map_page_into_agp(pages[i]);
 303 #endif
 304         return 0;
 305 }
 306 #endif /* for !CONFIG_X86 */
 307
 308 static int ttm_set_pages_caching(struct dma_pool *pool,
 309                                  struct page **pages, unsigned cpages)
 310 {
 311         int r = 0;
 312         /* Set page caching */
 313         if (pool->type & IS_UC) {
 314                 r = set_pages_array_uc(pages, cpages);
 315                 if (r)
 316                         pr_err("%s: Failed to set %d pages to uc!\n",
 317                                pool->dev_name, cpages);
 318         }
 319         if (pool->type & IS_WC) {
 320                 r = set_pages_array_wc(pages, cpages);
 321                 if (r)
 322                         pr_err("%s: Failed to set %d pages to wc!\n",
 323                                pool->dev_name, cpages);
 324         }
 325         return r;
 326 }
 327
 328 static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
 329 {
 330         dma_addr_t dma = d_page->dma;
 331         dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma);
 332
 333         kfree(d_page);
 334         d_page = NULL;
 335 }
 336 static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
 337 {
 338         struct dma_page *d_page;
 339
 340         d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
 341         if (!d_page)
 342                 return NULL;
 343
 344         d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
 345                                            &d_page->dma,
 346                                            pool->gfp_flags);
 347         if (d_page->vaddr)
 348                 d_page->p = virt_to_page(d_page->vaddr);
 349         else {
 350                 kfree(d_page);
 351                 d_page = NULL;
 352         }
 353         return d_page;
 354 }
 355 static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
 356 {
 357         enum pool_type type = IS_UNDEFINED;
 358
 359         if (flags & TTM_PAGE_FLAG_DMA32)
 360                 type |= IS_DMA32;
 361         if (cstate == tt_cached)
 362                 type |= IS_CACHED;
 363         else if (cstate == tt_uncached)
 364                 type |= IS_UC;
 365         else
 366                 type |= IS_WC;
 367
 368         return type;
 369 }
 370
 371 static void ttm_pool_update_free_locked(struct dma_pool *pool,
 372                                         unsigned freed_pages)
 373 {
 374         pool->npages_free -= freed_pages;
 375         pool->nfrees += freed_pages;
 376
 377 }
 378
 379 /* set memory back to wb and free the pages. */
 380 static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
 381                               struct page *pages[], unsigned npages)
 382 {
 383         struct dma_page *d_page, *tmp;
 384
 385         /* Don't set WB on WB page pool. */
 386         if (npages && !(pool->type & IS_CACHED) &&
 387             set_pages_array_wb(pages, npages))
 388                 pr_err("%s: Failed to set %d pages to wb!\n",
 389                        pool->dev_name, npages);
 390
 391         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 392                 list_del(&d_page->page_list);
 393                 __ttm_dma_free_page(pool, d_page);
 394         }
 395 }
 396
 397 static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
 398 {
 399         /* Don't set WB on WB page pool. */
 400         if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1))
 401                 pr_err("%s: Failed to set %d pages to wb!\n",
 402                        pool->dev_name, 1);
 403
 404         list_del(&d_page->page_list);
 405         __ttm_dma_free_page(pool, d_page);
 406 }
 407
 408 /*
 409  * Free pages from pool.
 410  *
 411  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 412  * number of pages in one go.
 413  *
 414  * @pool: to free the pages from
 415  * @nr_free: If set to true will free all pages in pool
 416  **/
 417 static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free)
 418 {
 419         unsigned long irq_flags;
 420         struct dma_page *dma_p, *tmp;
 421         struct page **pages_to_free;
 422         struct list_head d_pages;
 423         unsigned freed_pages = 0,
 424                  npages_to_free = nr_free;
 425
 426         if (NUM_PAGES_TO_ALLOC < nr_free)
 427                 npages_to_free = NUM_PAGES_TO_ALLOC;
 428 #if 0
 429         if (nr_free > 1) {
 430                 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
 431                          pool->dev_name, pool->name, current->pid,
 432                          npages_to_free, nr_free);
 433         }
 434 #endif
 435         pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 436                         GFP_KERNEL);
 437
 438         if (!pages_to_free) {
 439                 pr_err("%s: Failed to allocate memory for pool free operation\n",
 440                        pool->dev_name);
 441                 return 0;
 442         }
 443         INIT_LIST_HEAD(&d_pages);
 444 restart:
 445         spin_lock_irqsave(&pool->lock, irq_flags);
 446
 447         /* We picking the oldest ones off the list */
 448         list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
 449                                          page_list) {
 450                 if (freed_pages >= npages_to_free)
 451                         break;
 452
 453                 /* Move the dma_page from one list to another. */
 454                 list_move(&dma_p->page_list, &d_pages);
 455
 456                 pages_to_free[freed_pages++] = dma_p->p;
 457                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 458                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 459
 460                         ttm_pool_update_free_locked(pool, freed_pages);
 461                         /**
 462                          * Because changing page caching is costly
 463                          * we unlock the pool to prevent stalling.
 464                          */
 465                         spin_unlock_irqrestore(&pool->lock, irq_flags);
 466
 467                         ttm_dma_pages_put(pool, &d_pages, pages_to_free,
 468                                           freed_pages);
 469
 470                         INIT_LIST_HEAD(&d_pages);
 471
 472                         if (likely(nr_free != FREE_ALL_PAGES))
 473                                 nr_free -= freed_pages;
 474
 475                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 476                                 npages_to_free = nr_free;
 477                         else
 478                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 479
 480                         freed_pages = 0;
 481
 482                         /* free all so restart the processing */
 483                         if (nr_free)
 484                                 goto restart;
 485
 486                         /* Not allowed to fall through or break because
 487                          * following context is inside spinlock while we are
 488                          * outside here.
 489                          */
 490                         goto out;
 491
 492                 }
 493         }
 494
 495         /* remove range of pages from the pool */
 496         if (freed_pages) {
 497                 ttm_pool_update_free_locked(pool, freed_pages);
 498                 nr_free -= freed_pages;
 499         }
 500
 501         spin_unlock_irqrestore(&pool->lock, irq_flags);
 502
 503         if (freed_pages)
 504                 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
 505 out:
 506         kfree(pages_to_free);
 507         return nr_free;
 508 }
 509
 510 static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
 511 {
 512         struct device_pools *p;
 513         struct dma_pool *pool;
 514
 515         if (!dev)
 516                 return;
 517
 518         mutex_lock(&_manager->lock);
 519         list_for_each_entry_reverse(p, &_manager->pools, pools) {
 520                 if (p->dev != dev)
 521                         continue;
 522                 pool = p->pool;
 523                 if (pool->type != type)
 524                         continue;
 525
 526                 list_del(&p->pools);
 527                 kfree(p);
 528                 _manager->npools--;
 529                 break;
 530         }
 531         list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
 532                 if (pool->type != type)
 533                         continue;
 534                 /* Takes a spinlock.. */
 535                 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES);
 536                 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
 537                 /* This code path is called after _all_ references to the
 538                  * struct device has been dropped - so nobody should be
 539                  * touching it. In case somebody is trying to _add_ we are
 540                  * guarded by the mutex. */
 541                 list_del(&pool->pools);
 542                 kfree(pool);
 543                 break;
 544         }
 545         mutex_unlock(&_manager->lock);
 546 }
 547
 548 /*
 549  * On free-ing of the 'struct device' this deconstructor is run.
 550  * Albeit the pool might have already been freed earlier.
 551  */
 552 static void ttm_dma_pool_release(struct device *dev, void *res)
 553 {
 554         struct dma_pool *pool = *(struct dma_pool **)res;
 555
 556         if (pool)
 557                 ttm_dma_free_pool(dev, pool->type);
 558 }
 559
 560 static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
 561 {
 562         return *(struct dma_pool **)res == match_data;
 563 }
 564
 565 static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
 566                                           enum pool_type type)
 567 {
 568         char *n[] = {"wc", "uc", "cached", " dma32", "unknown",};
 569         enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED};
 570         struct device_pools *sec_pool = NULL;
 571         struct dma_pool *pool = NULL, **ptr;
 572         unsigned i;
 573         int ret = -ENODEV;
 574         char *p;
 575
 576         if (!dev)
 577                 return NULL;
 578
 579         ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
 580         if (!ptr)
 581                 return NULL;
 582
 583         ret = -ENOMEM;
 584
 585         pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
 586                             dev_to_node(dev));
 587         if (!pool)
 588                 goto err_mem;
 589
 590         sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
 591                                 dev_to_node(dev));
 592         if (!sec_pool)
 593                 goto err_mem;
 594
 595         INIT_LIST_HEAD(&sec_pool->pools);
 596         sec_pool->dev = dev;
 597         sec_pool->pool =  pool;
 598
 599         INIT_LIST_HEAD(&pool->free_list);
 600         INIT_LIST_HEAD(&pool->inuse_list);
 601         INIT_LIST_HEAD(&pool->pools);
 602         spin_lock_init(&pool->lock);
 603         pool->dev = dev;
 604         pool->npages_free = pool->npages_in_use = 0;
 605         pool->nfrees = 0;
 606         pool->gfp_flags = flags;
 607         pool->size = PAGE_SIZE;
 608         pool->type = type;
 609         pool->nrefills = 0;
 610         p = pool->name;
 611         for (i = 0; i < 5; i++) {
 612                 if (type & t[i]) {
 613                         p += snprintf(p, sizeof(pool->name) - (p - pool->name),
 614                                       "%s", n[i]);
 615                 }
 616         }
 617         *p = 0;
 618         /* We copy the name for pr_ calls b/c when dma_pool_destroy is called
 619          * - the kobj->name has already been deallocated.*/
 620         snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
 621                  dev_driver_string(dev), dev_name(dev));
 622         mutex_lock(&_manager->lock);
 623         /* You can get the dma_pool from either the global: */
 624         list_add(&sec_pool->pools, &_manager->pools);
 625         _manager->npools++;
 626         /* or from 'struct device': */
 627         list_add(&pool->pools, &dev->dma_pools);
 628         mutex_unlock(&_manager->lock);
 629
 630         *ptr = pool;
 631         devres_add(dev, ptr);
 632
 633         return pool;
 634 err_mem:
 635         devres_free(ptr);
 636         kfree(sec_pool);
 637         kfree(pool);
 638         return ERR_PTR(ret);
 639 }
 640
 641 static struct dma_pool *ttm_dma_find_pool(struct device *dev,
 642                                           enum pool_type type)
 643 {
 644         struct dma_pool *pool, *tmp, *found = NULL;
 645
 646         if (type == IS_UNDEFINED)
 647                 return found;
 648
 649         /* NB: We iterate on the 'struct dev' which has no spinlock, but
 650          * it does have a kref which we have taken. The kref is taken during
 651          * graphic driver loading - in the drm_pci_init it calls either
 652          * pci_dev_get or pci_register_driver which both end up taking a kref
 653          * on 'struct device'.
 654          *
 655          * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
 656          * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
 657          * thing is at that point of time there are no pages associated with the
 658          * driver so this function will not be called.
 659          */
 660         list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) {
 661                 if (pool->type != type)
 662                         continue;
 663                 found = pool;
 664                 break;
 665         }
 666         return found;
 667 }
 668
 669 /*
 670  * Free pages the pages that failed to change the caching state. If there
 671  * are pages that have changed their caching state already put them to the
 672  * pool.
 673  */
 674 static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
 675                                                  struct list_head *d_pages,
 676                                                  struct page **failed_pages,
 677                                                  unsigned cpages)
 678 {
 679         struct dma_page *d_page, *tmp;
 680         struct page *p;
 681         unsigned i = 0;
 682
 683         p = failed_pages[0];
 684         if (!p)
 685                 return;
 686         /* Find the failed page. */
 687         list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 688                 if (d_page->p != p)
 689                         continue;
 690                 /* .. and then progress over the full list. */
 691                 list_del(&d_page->page_list);
 692                 __ttm_dma_free_page(pool, d_page);
 693                 if (++i < cpages)
 694                         p = failed_pages[i];
 695                 else
 696                         break;
 697         }
 698
 699 }
 700
 701 /*
 702  * Allocate 'count' pages, and put 'need' number of them on the
 703  * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
 704  * The full list of pages should also be on 'd_pages'.
 705  * We return zero for success, and negative numbers as errors.
 706  */
 707 static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
 708                                         struct list_head *d_pages,
 709                                         unsigned count)
 710 {
 711         struct page **caching_array;
 712         struct dma_page *dma_p;
 713         struct page *p;
 714         int r = 0;
 715         unsigned i, cpages;
 716         unsigned max_cpages = min(count,
 717                         (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 718
 719         /* allocate array for page caching change */
 720         caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 721
 722         if (!caching_array) {
 723                 pr_err("%s: Unable to allocate table for new pages\n",
 724                        pool->dev_name);
 725                 return -ENOMEM;
 726         }
 727
 728         if (count > 1) {
 729                 pr_debug("%s: (%s:%d) Getting %d pages\n",
 730                          pool->dev_name, pool->name, current->pid, count);
 731         }
 732
 733         for (i = 0, cpages = 0; i < count; ++i) {
 734                 dma_p = __ttm_dma_alloc_page(pool);
 735                 if (!dma_p) {
 736                         pr_err("%s: Unable to get page %u\n",
 737                                pool->dev_name, i);
 738
 739                         /* store already allocated pages in the pool after
 740                          * setting the caching state */
 741                         if (cpages) {
 742                                 r = ttm_set_pages_caching(pool, caching_array,
 743                                                           cpages);
 744                                 if (r)
 745                                         ttm_dma_handle_caching_state_failure(
 746                                                 pool, d_pages, caching_array,
 747                                                 cpages);
 748                         }
 749                         r = -ENOMEM;
 750                         goto out;
 751                 }
 752                 p = dma_p->p;
 753 #ifdef CONFIG_HIGHMEM
 754                 /* gfp flags of highmem page should never be dma32 so we
 755                  * we should be fine in such case
 756                  */
 757                 if (!PageHighMem(p))
 758 #endif
 759                 {
 760                         caching_array[cpages++] = p;
 761                         if (cpages == max_cpages) {
 762                                 /* Note: Cannot hold the spinlock */
 763                                 r = ttm_set_pages_caching(pool, caching_array,
 764                                                  cpages);
 765                                 if (r) {
 766                                         ttm_dma_handle_caching_state_failure(
 767                                                 pool, d_pages, caching_array,
 768                                                 cpages);
 769                                         goto out;
 770                                 }
 771                                 cpages = 0;
 772                         }
 773                 }
 774                 list_add(&dma_p->page_list, d_pages);
 775         }
 776
 777         if (cpages) {
 778                 r = ttm_set_pages_caching(pool, caching_array, cpages);
 779                 if (r)
 780                         ttm_dma_handle_caching_state_failure(pool, d_pages,
 781                                         caching_array, cpages);
 782         }
 783 out:
 784         kfree(caching_array);
 785         return r;
 786 }
 787
 788 /*
 789  * @return count of pages still required to fulfill the request.
 790  */
 791 static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
 792                                          unsigned long *irq_flags)
 793 {
 794         unsigned count = _manager->options.small;
 795         int r = pool->npages_free;
 796
 797         if (count > pool->npages_free) {
 798                 struct list_head d_pages;
 799
 800                 INIT_LIST_HEAD(&d_pages);
 801
 802                 spin_unlock_irqrestore(&pool->lock, *irq_flags);
 803
 804                 /* Returns how many more are neccessary to fulfill the
 805                  * request. */
 806                 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
 807
 808                 spin_lock_irqsave(&pool->lock, *irq_flags);
 809                 if (!r) {
 810                         /* Add the fresh to the end.. */
 811                         list_splice(&d_pages, &pool->free_list);
 812                         ++pool->nrefills;
 813                         pool->npages_free += count;
 814                         r = count;
 815                 } else {
 816                         struct dma_page *d_page;
 817                         unsigned cpages = 0;
 818
 819                         pr_err("%s: Failed to fill %s pool (r:%d)!\n",
 820                                pool->dev_name, pool->name, r);
 821
 822                         list_for_each_entry(d_page, &d_pages, page_list) {
 823                                 cpages++;
 824                         }
 825                         list_splice_tail(&d_pages, &pool->free_list);
 826                         pool->npages_free += cpages;
 827                         r = cpages;
 828                 }
 829         }
 830         return r;
 831 }
 832
 833 /*
 834  * @return count of pages still required to fulfill the request.
 835  * The populate list is actually a stack (not that is matters as TTM
 836  * allocates one page at a time.
 837  */
 838 static int ttm_dma_pool_get_pages(struct dma_pool *pool,
 839                                   struct ttm_dma_tt *ttm_dma,
 840                                   unsigned index)
 841 {
 842         struct dma_page *d_page;
 843         struct ttm_tt *ttm = &ttm_dma->ttm;
 844         unsigned long irq_flags;
 845         int count, r = -ENOMEM;
 846
 847         spin_lock_irqsave(&pool->lock, irq_flags);
 848         count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
 849         if (count) {
 850                 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
 851                 ttm->pages[index] = d_page->p;
 852                 ttm_dma->dma_address[index] = d_page->dma;
 853                 list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
 854                 r = 0;
 855                 pool->npages_in_use += 1;
 856                 pool->npages_free -= 1;
 857         }
 858         spin_unlock_irqrestore(&pool->lock, irq_flags);
 859         return r;
 860 }
 861
 862 /*
 863  * On success pages list will hold count number of correctly
 864  * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
 865  */
 866 int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 867 {
 868         struct ttm_tt *ttm = &ttm_dma->ttm;
 869         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 870         struct dma_pool *pool;
 871         enum pool_type type;
 872         unsigned i;
 873         gfp_t gfp_flags;
 874         int ret;
 875
 876         if (ttm->state != tt_unpopulated)
 877                 return 0;
 878
 879         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 880         if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 881                 gfp_flags = GFP_USER | GFP_DMA32;
 882         else
 883                 gfp_flags = GFP_HIGHUSER;
 884         if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 885                 gfp_flags |= __GFP_ZERO;
 886
 887         pool = ttm_dma_find_pool(dev, type);
 888         if (!pool) {
 889                 pool = ttm_dma_pool_init(dev, gfp_flags, type);
 890                 if (IS_ERR_OR_NULL(pool)) {
 891                         return -ENOMEM;
 892                 }
 893         }
 894
 895         INIT_LIST_HEAD(&ttm_dma->pages_list);
 896         for (i = 0; i < ttm->num_pages; ++i) {
 897                 ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
 898                 if (ret != 0) {
 899                         ttm_dma_unpopulate(ttm_dma, dev);
 900                         return -ENOMEM;
 901                 }
 902
 903                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 904                                                 false, false);
 905                 if (unlikely(ret != 0)) {
 906                         ttm_dma_unpopulate(ttm_dma, dev);
 907                         return -ENOMEM;
 908                 }
 909         }
 910
 911         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 912                 ret = ttm_tt_swapin(ttm);
 913                 if (unlikely(ret != 0)) {
 914                         ttm_dma_unpopulate(ttm_dma, dev);
 915                         return ret;
 916                 }
 917         }
 918
 919         ttm->state = tt_unbound;
 920         return 0;
 921 }
 922 EXPORT_SYMBOL_GPL(ttm_dma_populate);
 923
 924 /* Get good estimation how many pages are free in pools */
 925 static int ttm_dma_pool_get_num_unused_pages(void)
 926 {
 927         struct device_pools *p;
 928         unsigned total = 0;
 929
 930         mutex_lock(&_manager->lock);
 931         list_for_each_entry(p, &_manager->pools, pools)
 932                 total += p->pool->npages_free;
 933         mutex_unlock(&_manager->lock);
 934         return total;
 935 }
 936
 937 /* Put all pages in pages list to correct pool to wait for reuse */
 938 void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 939 {
 940         struct ttm_tt *ttm = &ttm_dma->ttm;
 941         struct dma_pool *pool;
 942         struct dma_page *d_page, *next;
 943         enum pool_type type;
 944         bool is_cached = false;
 945         unsigned count = 0, i, npages = 0;
 946         unsigned long irq_flags;
 947
 948         type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 949         pool = ttm_dma_find_pool(dev, type);
 950         if (!pool)
 951                 return;
 952
 953         is_cached = (ttm_dma_find_pool(pool->dev,
 954                      ttm_to_type(ttm->page_flags, tt_cached)) == pool);
 955
 956         /* make sure pages array match list and count number of pages */
 957         list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) {
 958                 ttm->pages[count] = d_page->p;
 959                 count++;
 960         }
 961
 962         spin_lock_irqsave(&pool->lock, irq_flags);
 963         pool->npages_in_use -= count;
 964         if (is_cached) {
 965                 pool->nfrees += count;
 966         } else {
 967                 pool->npages_free += count;
 968                 list_splice(&ttm_dma->pages_list, &pool->free_list);
 969                 npages = count;
 970                 if (pool->npages_free > _manager->options.max_size) {
 971                         npages = pool->npages_free - _manager->options.max_size;
 972                         /* free at least NUM_PAGES_TO_ALLOC number of pages
 973                          * to reduce calls to set_memory_wb */
 974                         if (npages < NUM_PAGES_TO_ALLOC)
 975                                 npages = NUM_PAGES_TO_ALLOC;
 976                 }
 977         }
 978         spin_unlock_irqrestore(&pool->lock, irq_flags);
 979
 980         if (is_cached) {
 981                 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) {
 982                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 983                                                  d_page->p);
 984                         ttm_dma_page_put(pool, d_page);
 985                 }
 986         } else {
 987                 for (i = 0; i < count; i++) {
 988                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 989                                                  ttm->pages[i]);
 990                 }
 991         }
 992
 993         INIT_LIST_HEAD(&ttm_dma->pages_list);
 994         for (i = 0; i < ttm->num_pages; i++) {
 995                 ttm->pages[i] = NULL;
 996                 ttm_dma->dma_address[i] = 0;
 997         }
 998
 999         /* shrink pool if necessary (only on !is_cached pools)*/
1000         if (npages)
1001                 ttm_dma_page_pool_free(pool, npages);
1002         ttm->state = tt_unpopulated;
1003 }
1004 EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
1005
1006 /**
1007  * Callback for mm to request pool to reduce number of page held.
1008  */
1009 static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
1010                                   struct shrink_control *sc)
1011 {
1012         static atomic_t start_pool = ATOMIC_INIT(0);
1013         unsigned idx = 0;
1014         unsigned pool_offset = atomic_add_return(1, &start_pool);
1015         unsigned shrink_pages = sc->nr_to_scan;
1016         struct device_pools *p;
1017
1018         if (list_empty(&_manager->pools))
1019                 return 0;
1020
1021         mutex_lock(&_manager->lock);
1022         pool_offset = pool_offset % _manager->npools;
1023         list_for_each_entry(p, &_manager->pools, pools) {
1024                 unsigned nr_free;
1025
1026                 if (!p->dev)
1027                         continue;
1028                 if (shrink_pages == 0)
1029                         break;
1030                 /* Do it in round-robin fashion. */
1031                 if (++idx < pool_offset)
1032                         continue;
1033                 nr_free = shrink_pages;
1034                 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free);
1035                 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
1036                          p->pool->dev_name, p->pool->name, current->pid,
1037                          nr_free, shrink_pages);
1038         }
1039         mutex_unlock(&_manager->lock);
1040         /* return estimated number of unused pages in pool */
1041         return ttm_dma_pool_get_num_unused_pages();
1042 }
1043
1044 static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
1045 {
1046         manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink;
1047         manager->mm_shrink.seeks = 1;
1048         register_shrinker(&manager->mm_shrink);
1049 }
1050
1051 static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
1052 {
1053         unregister_shrinker(&manager->mm_shrink);
1054 }
1055
1056 int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1057 {
1058         int ret = -ENOMEM;
1059
1060         WARN_ON(_manager);
1061
1062         pr_info("Initializing DMA pool allocator\n");
1063
1064         _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1065         if (!_manager)
1066                 goto err;
1067
1068         mutex_init(&_manager->lock);
1069         INIT_LIST_HEAD(&_manager->pools);
1070
1071         _manager->options.max_size = max_pages;
1072         _manager->options.small = SMALL_ALLOCATION;
1073         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1074
1075         /* This takes care of auto-freeing the _manager */
1076         ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1077                                    &glob->kobj, "dma_pool");
1078         if (unlikely(ret != 0)) {
1079                 kobject_put(&_manager->kobj);
1080                 goto err;
1081         }
1082         ttm_dma_pool_mm_shrink_init(_manager);
1083         return 0;
1084 err:
1085         return ret;
1086 }
1087
1088 void ttm_dma_page_alloc_fini(void)
1089 {
1090         struct device_pools *p, *t;
1091
1092         pr_info("Finalizing DMA pool allocator\n");
1093         ttm_dma_pool_mm_shrink_fini(_manager);
1094
1095         list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
1096                 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
1097                         current->pid);
1098                 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
1099                         ttm_dma_pool_match, p->pool));
1100                 ttm_dma_free_pool(p->dev, p->pool->type);
1101         }
1102         kobject_put(&_manager->kobj);
1103         _manager = NULL;
1104 }
1105
1106 int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
1107 {
1108         struct device_pools *p;
1109         struct dma_pool *pool = NULL;
1110         char *h[] = {"pool", "refills", "pages freed", "inuse", "available",
1111                      "name", "virt", "busaddr"};
1112
1113         if (!_manager) {
1114                 seq_printf(m, "No pool allocator running.\n");
1115                 return 0;
1116         }
1117         seq_printf(m, "%13s %12s %13s %8s %8s %8s\n",
1118                    h[0], h[1], h[2], h[3], h[4], h[5]);
1119         mutex_lock(&_manager->lock);
1120         list_for_each_entry(p, &_manager->pools, pools) {
1121                 struct device *dev = p->dev;
1122                 if (!dev)
1123                         continue;
1124                 pool = p->pool;
1125                 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
1126                                 pool->name, pool->nrefills,
1127                                 pool->nfrees, pool->npages_in_use,
1128                                 pool->npages_free,
1129                                 pool->dev_name);
1130         }
1131         mutex_unlock(&_manager->lock);
1132         return 0;
1133 }
1134 EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);