drivers/gpu/drm/ttm/ttm_page_alloc.c

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