sys/dev/drm2/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  * Copyright (c) 2013 The FreeBSD Foundation
  29  * All rights reserved.
  30  *
  31  * Portions of this software were developed by Konstantin Belousov
  32  * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
  33  */
  34
  35 /* simple list based uncached page pool
  36  * - Pool collects resently freed pages for reuse
  37  * - Use page->lru to keep a free list
  38  * - doesn't track currently in use pages
  39  */
  40
  41 #include <sys/cdefs.h>
  42 __FBSDID("$FreeBSD$");
  43
  44 #include <dev/drm2/drmP.h>
  45 #include <dev/drm2/ttm/ttm_bo_driver.h>
  46 #include <dev/drm2/ttm/ttm_page_alloc.h>
  47 #include <vm/vm_pageout.h>
  48
  49 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(vm_page_t))
  50 #define SMALL_ALLOCATION                16
  51 #define FREE_ALL_PAGES                  (~0U)
  52 /* times are in msecs */
  53 #define PAGE_FREE_INTERVAL              1000
  54
  55 /**
  56  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  57  *
  58  * @lock: Protects the shared pool from concurrnet access. Must be used with
  59  * irqsave/irqrestore variants because pool allocator maybe called from
  60  * delayed work.
  61  * @fill_lock: Prevent concurrent calls to fill.
  62  * @list: Pool of free uc/wc pages for fast reuse.
  63  * @gfp_flags: Flags to pass for alloc_page.
  64  * @npages: Number of pages in pool.
  65  */
  66 struct ttm_page_pool {
  67         struct mtx              lock;
  68         bool                    fill_lock;
  69         bool                    dma32;
  70         struct pglist           list;
  71         int                     ttm_page_alloc_flags;
  72         unsigned                npages;
  73         char                    *name;
  74         unsigned long           nfrees;
  75         unsigned long           nrefills;
  76 };
  77
  78 /**
  79  * Limits for the pool. They are handled without locks because only place where
  80  * they may change is in sysfs store. They won't have immediate effect anyway
  81  * so forcing serialization to access them is pointless.
  82  */
  83
  84 struct ttm_pool_opts {
  85         unsigned        alloc_size;
  86         unsigned        max_size;
  87         unsigned        small;
  88 };
  89
  90 #define NUM_POOLS 4
  91
  92 /**
  93  * struct ttm_pool_manager - Holds memory pools for fst allocation
  94  *
  95  * Manager is read only object for pool code so it doesn't need locking.
  96  *
  97  * @free_interval: minimum number of jiffies between freeing pages from pool.
  98  * @page_alloc_inited: reference counting for pool allocation.
  99  * @work: Work that is used to shrink the pool. Work is only run when there is
 100  * some pages to free.
 101  * @small_allocation: Limit in number of pages what is small allocation.
 102  *
 103  * @pools: All pool objects in use.
 104  **/
 105 struct ttm_pool_manager {
 106         unsigned int kobj_ref;
 107         eventhandler_tag lowmem_handler;
 108         struct ttm_pool_opts    options;
 109
 110         union {
 111                 struct ttm_page_pool    u_pools[NUM_POOLS];
 112                 struct _utag {
 113                         struct ttm_page_pool    u_wc_pool;
 114                         struct ttm_page_pool    u_uc_pool;
 115                         struct ttm_page_pool    u_wc_pool_dma32;
 116                         struct ttm_page_pool    u_uc_pool_dma32;
 117                 } _ut;
 118         } _u;
 119 };
 120
 121 #define pools _u.u_pools
 122 #define wc_pool _u._ut.u_wc_pool
 123 #define uc_pool _u._ut.u_uc_pool
 124 #define wc_pool_dma32 _u._ut.u_wc_pool_dma32
 125 #define uc_pool_dma32 _u._ut.u_uc_pool_dma32
 126
 127 MALLOC_DEFINE(M_TTM_POOLMGR, "ttm_poolmgr", "TTM Pool Manager");
 128
 129 static void
 130 ttm_vm_page_free(vm_page_t m)
 131 {
 132
 133         KASSERT(m->object == NULL, ("ttm page %p is owned", m));
 134         KASSERT(m->wire_count == 1, ("ttm lost wire %p", m));
 135         KASSERT((m->flags & PG_FICTITIOUS) != 0, ("ttm lost fictitious %p", m));
 136         KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("ttm got unmanaged %p", m));
 137         m->flags &= ~PG_FICTITIOUS;
 138         m->oflags |= VPO_UNMANAGED;
 139         vm_page_unwire(m, PQ_NONE);
 140         vm_page_free(m);
 141 }
 142
 143 static vm_memattr_t
 144 ttm_caching_state_to_vm(enum ttm_caching_state cstate)
 145 {
 146
 147         switch (cstate) {
 148         case tt_uncached:
 149                 return (VM_MEMATTR_UNCACHEABLE);
 150         case tt_wc:
 151                 return (VM_MEMATTR_WRITE_COMBINING);
 152         case tt_cached:
 153                 return (VM_MEMATTR_WRITE_BACK);
 154         }
 155         panic("caching state %d\n", cstate);
 156 }
 157
 158 static vm_page_t
 159 ttm_vm_page_alloc_dma32(int req, vm_memattr_t memattr)
 160 {
 161         vm_page_t p;
 162         int tries;
 163
 164         for (tries = 0; ; tries++) {
 165                 p = vm_page_alloc_contig(NULL, 0, req, 1, 0, 0xffffffff,
 166                     PAGE_SIZE, 0, memattr);
 167                 if (p != NULL || tries > 2)
 168                         return (p);
 169                 if (!vm_page_reclaim_contig(req, 1, 0, 0xffffffff,
 170                     PAGE_SIZE, 0))
 171                         vm_wait(NULL);
 172         }
 173 }
 174
 175 static vm_page_t
 176 ttm_vm_page_alloc_any(int req, vm_memattr_t memattr)
 177 {
 178         vm_page_t p;
 179
 180         while (1) {
 181                 p = vm_page_alloc(NULL, 0, req);
 182                 if (p != NULL)
 183                         break;
 184                 vm_wait(NULL);
 185         }
 186         pmap_page_set_memattr(p, memattr);
 187         return (p);
 188 }
 189
 190 static vm_page_t
 191 ttm_vm_page_alloc(int flags, enum ttm_caching_state cstate)
 192 {
 193         vm_page_t p;
 194         vm_memattr_t memattr;
 195         int req;
 196
 197         memattr = ttm_caching_state_to_vm(cstate);
 198         req = VM_ALLOC_NORMAL | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ;
 199         if ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0)
 200                 req |= VM_ALLOC_ZERO;
 201
 202         if ((flags & TTM_PAGE_FLAG_DMA32) != 0)
 203                 p = ttm_vm_page_alloc_dma32(req, memattr);
 204         else
 205                 p = ttm_vm_page_alloc_any(req, memattr);
 206
 207         if (p != NULL) {
 208                 p->oflags &= ~VPO_UNMANAGED;
 209                 p->flags |= PG_FICTITIOUS;
 210         }
 211         return (p);
 212 }
 213
 214 static void ttm_pool_kobj_release(struct ttm_pool_manager *m)
 215 {
 216
 217         free(m, M_TTM_POOLMGR);
 218 }
 219
 220 #if 0
 221 /* XXXKIB sysctl */
 222 static ssize_t ttm_pool_store(struct ttm_pool_manager *m,
 223                 struct attribute *attr, const char *buffer, size_t size)
 224 {
 225         int chars;
 226         unsigned val;
 227         chars = sscanf(buffer, "%u", &val);
 228         if (chars == 0)
 229                 return size;
 230
 231         /* Convert kb to number of pages */
 232         val = val / (PAGE_SIZE >> 10);
 233
 234         if (attr == &ttm_page_pool_max)
 235                 m->options.max_size = val;
 236         else if (attr == &ttm_page_pool_small)
 237                 m->options.small = val;
 238         else if (attr == &ttm_page_pool_alloc_size) {
 239                 if (val > NUM_PAGES_TO_ALLOC*8) {
 240                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 241                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 242                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 243                         return size;
 244                 } else if (val > NUM_PAGES_TO_ALLOC) {
 245                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 246                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 247                 }
 248                 m->options.alloc_size = val;
 249         }
 250
 251         return size;
 252 }
 253
 254 static ssize_t ttm_pool_show(struct ttm_pool_manager *m,
 255                 struct attribute *attr, char *buffer)
 256 {
 257         unsigned val = 0;
 258
 259         if (attr == &ttm_page_pool_max)
 260                 val = m->options.max_size;
 261         else if (attr == &ttm_page_pool_small)
 262                 val = m->options.small;
 263         else if (attr == &ttm_page_pool_alloc_size)
 264                 val = m->options.alloc_size;
 265
 266         val = val * (PAGE_SIZE >> 10);
 267
 268         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 269 }
 270 #endif
 271
 272 static struct ttm_pool_manager *_manager;
 273
 274 static int set_pages_array_wb(vm_page_t *pages, int addrinarray)
 275 {
 276 #ifdef TTM_HAS_AGP
 277         int i;
 278
 279         for (i = 0; i < addrinarray; i++)
 280                 pmap_page_set_memattr(pages[i], VM_MEMATTR_WRITE_BACK);
 281 #endif
 282         return 0;
 283 }
 284
 285 static int set_pages_array_wc(vm_page_t *pages, int addrinarray)
 286 {
 287 #ifdef TTM_HAS_AGP
 288         int i;
 289
 290         for (i = 0; i < addrinarray; i++)
 291                 pmap_page_set_memattr(pages[i], VM_MEMATTR_WRITE_COMBINING);
 292 #endif
 293         return 0;
 294 }
 295
 296 static int set_pages_array_uc(vm_page_t *pages, int addrinarray)
 297 {
 298 #ifdef TTM_HAS_AGP
 299         int i;
 300
 301         for (i = 0; i < addrinarray; i++)
 302                 pmap_page_set_memattr(pages[i], VM_MEMATTR_UNCACHEABLE);
 303 #endif
 304         return 0;
 305 }
 306
 307 /**
 308  * Select the right pool or requested caching state and ttm flags. */
 309 static struct ttm_page_pool *ttm_get_pool(int flags,
 310                 enum ttm_caching_state cstate)
 311 {
 312         int pool_index;
 313
 314         if (cstate == tt_cached)
 315                 return NULL;
 316
 317         if (cstate == tt_wc)
 318                 pool_index = 0x0;
 319         else
 320                 pool_index = 0x1;
 321
 322         if (flags & TTM_PAGE_FLAG_DMA32)
 323                 pool_index |= 0x2;
 324
 325         return &_manager->pools[pool_index];
 326 }
 327
 328 /* set memory back to wb and free the pages. */
 329 static void ttm_pages_put(vm_page_t *pages, unsigned npages)
 330 {
 331         unsigned i;
 332
 333         /* Our VM handles vm memattr automatically on the page free. */
 334         if (set_pages_array_wb(pages, npages))
 335                 printf("[TTM] Failed to set %d pages to wb!\n", npages);
 336         for (i = 0; i < npages; ++i)
 337                 ttm_vm_page_free(pages[i]);
 338 }
 339
 340 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 341                 unsigned freed_pages)
 342 {
 343         pool->npages -= freed_pages;
 344         pool->nfrees += freed_pages;
 345 }
 346
 347 /**
 348  * Free pages from pool.
 349  *
 350  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 351  * number of pages in one go.
 352  *
 353  * @pool: to free the pages from
 354  * @free_all: If set to true will free all pages in pool
 355  **/
 356 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 357 {
 358         vm_page_t p, p1;
 359         vm_page_t *pages_to_free;
 360         unsigned freed_pages = 0,
 361                  npages_to_free = nr_free;
 362         unsigned i;
 363
 364         if (NUM_PAGES_TO_ALLOC < nr_free)
 365                 npages_to_free = NUM_PAGES_TO_ALLOC;
 366
 367         pages_to_free = malloc(npages_to_free * sizeof(vm_page_t),
 368             M_TEMP, M_WAITOK | M_ZERO);
 369
 370 restart:
 371         mtx_lock(&pool->lock);
 372
 373         TAILQ_FOREACH_REVERSE_SAFE(p, &pool->list, pglist, plinks.q, p1) {
 374                 if (freed_pages >= npages_to_free)
 375                         break;
 376
 377                 pages_to_free[freed_pages++] = p;
 378                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 379                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 380                         /* remove range of pages from the pool */
 381                         for (i = 0; i < freed_pages; i++)
 382                                 TAILQ_REMOVE(&pool->list, pages_to_free[i], plinks.q);
 383
 384                         ttm_pool_update_free_locked(pool, freed_pages);
 385                         /**
 386                          * Because changing page caching is costly
 387                          * we unlock the pool to prevent stalling.
 388                          */
 389                         mtx_unlock(&pool->lock);
 390
 391                         ttm_pages_put(pages_to_free, freed_pages);
 392                         if (likely(nr_free != FREE_ALL_PAGES))
 393                                 nr_free -= freed_pages;
 394
 395                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 396                                 npages_to_free = nr_free;
 397                         else
 398                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 399
 400                         freed_pages = 0;
 401
 402                         /* free all so restart the processing */
 403                         if (nr_free)
 404                                 goto restart;
 405
 406                         /* Not allowed to fall through or break because
 407                          * following context is inside spinlock while we are
 408                          * outside here.
 409                          */
 410                         goto out;
 411
 412                 }
 413         }
 414
 415         /* remove range of pages from the pool */
 416         if (freed_pages) {
 417                 for (i = 0; i < freed_pages; i++)
 418                         TAILQ_REMOVE(&pool->list, pages_to_free[i], plinks.q);
 419
 420                 ttm_pool_update_free_locked(pool, freed_pages);
 421                 nr_free -= freed_pages;
 422         }
 423
 424         mtx_unlock(&pool->lock);
 425
 426         if (freed_pages)
 427                 ttm_pages_put(pages_to_free, freed_pages);
 428 out:
 429         free(pages_to_free, M_TEMP);
 430         return nr_free;
 431 }
 432
 433 /* Get good estimation how many pages are free in pools */
 434 static int ttm_pool_get_num_unused_pages(void)
 435 {
 436         unsigned i;
 437         int total = 0;
 438         for (i = 0; i < NUM_POOLS; ++i)
 439                 total += _manager->pools[i].npages;
 440
 441         return total;
 442 }
 443
 444 /**
 445  * Callback for mm to request pool to reduce number of page held.
 446  */
 447 static int ttm_pool_mm_shrink(void *arg)
 448 {
 449         static unsigned int start_pool = 0;
 450         unsigned i;
 451         unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
 452         struct ttm_page_pool *pool;
 453         int shrink_pages = 100; /* XXXKIB */
 454
 455         pool_offset = pool_offset % NUM_POOLS;
 456         /* select start pool in round robin fashion */
 457         for (i = 0; i < NUM_POOLS; ++i) {
 458                 unsigned nr_free = shrink_pages;
 459                 if (shrink_pages == 0)
 460                         break;
 461                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 462                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 463         }
 464         /* return estimated number of unused pages in pool */
 465         return ttm_pool_get_num_unused_pages();
 466 }
 467
 468 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 469 {
 470
 471         manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
 472             ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
 473 }
 474
 475 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 476 {
 477
 478         EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
 479 }
 480
 481 static int ttm_set_pages_caching(vm_page_t *pages,
 482                 enum ttm_caching_state cstate, unsigned cpages)
 483 {
 484         int r = 0;
 485         /* Set page caching */
 486         switch (cstate) {
 487         case tt_uncached:
 488                 r = set_pages_array_uc(pages, cpages);
 489                 if (r)
 490                         printf("[TTM] Failed to set %d pages to uc!\n", cpages);
 491                 break;
 492         case tt_wc:
 493                 r = set_pages_array_wc(pages, cpages);
 494                 if (r)
 495                         printf("[TTM] Failed to set %d pages to wc!\n", cpages);
 496                 break;
 497         default:
 498                 break;
 499         }
 500         return r;
 501 }
 502
 503 /**
 504  * Free pages the pages that failed to change the caching state. If there is
 505  * any pages that have changed their caching state already put them to the
 506  * pool.
 507  */
 508 static void ttm_handle_caching_state_failure(struct pglist *pages,
 509                 int ttm_flags, enum ttm_caching_state cstate,
 510                 vm_page_t *failed_pages, unsigned cpages)
 511 {
 512         unsigned i;
 513         /* Failed pages have to be freed */
 514         for (i = 0; i < cpages; ++i) {
 515                 TAILQ_REMOVE(pages, failed_pages[i], plinks.q);
 516                 ttm_vm_page_free(failed_pages[i]);
 517         }
 518 }
 519
 520 /**
 521  * Allocate new pages with correct caching.
 522  *
 523  * This function is reentrant if caller updates count depending on number of
 524  * pages returned in pages array.
 525  */
 526 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
 527                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 528 {
 529         vm_page_t *caching_array;
 530         vm_page_t p;
 531         int r = 0;
 532         unsigned i, cpages;
 533         unsigned max_cpages = min(count,
 534                         (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
 535
 536         /* allocate array for page caching change */
 537         caching_array = malloc(max_cpages * sizeof(vm_page_t), M_TEMP,
 538             M_WAITOK | M_ZERO);
 539
 540         for (i = 0, cpages = 0; i < count; ++i) {
 541                 p = ttm_vm_page_alloc(ttm_alloc_flags, cstate);
 542                 if (!p) {
 543                         printf("[TTM] Unable to get page %u\n", i);
 544
 545                         /* store already allocated pages in the pool after
 546                          * setting the caching state */
 547                         if (cpages) {
 548                                 r = ttm_set_pages_caching(caching_array,
 549                                                           cstate, cpages);
 550                                 if (r)
 551                                         ttm_handle_caching_state_failure(pages,
 552                                                 ttm_flags, cstate,
 553                                                 caching_array, cpages);
 554                         }
 555                         r = -ENOMEM;
 556                         goto out;
 557                 }
 558
 559 #ifdef CONFIG_HIGHMEM /* KIB: nop */
 560                 /* gfp flags of highmem page should never be dma32 so we
 561                  * we should be fine in such case
 562                  */
 563                 if (!PageHighMem(p))
 564 #endif
 565                 {
 566                         caching_array[cpages++] = p;
 567                         if (cpages == max_cpages) {
 568
 569                                 r = ttm_set_pages_caching(caching_array,
 570                                                 cstate, cpages);
 571                                 if (r) {
 572                                         ttm_handle_caching_state_failure(pages,
 573                                                 ttm_flags, cstate,
 574                                                 caching_array, cpages);
 575                                         goto out;
 576                                 }
 577                                 cpages = 0;
 578                         }
 579                 }
 580
 581                 TAILQ_INSERT_HEAD(pages, p, plinks.q);
 582         }
 583
 584         if (cpages) {
 585                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 586                 if (r)
 587                         ttm_handle_caching_state_failure(pages,
 588                                         ttm_flags, cstate,
 589                                         caching_array, cpages);
 590         }
 591 out:
 592         free(caching_array, M_TEMP);
 593
 594         return r;
 595 }
 596
 597 /**
 598  * Fill the given pool if there aren't enough pages and the requested number of
 599  * pages is small.
 600  */
 601 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 602     int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 603 {
 604         vm_page_t p;
 605         int r;
 606         unsigned cpages = 0;
 607         /**
 608          * Only allow one pool fill operation at a time.
 609          * If pool doesn't have enough pages for the allocation new pages are
 610          * allocated from outside of pool.
 611          */
 612         if (pool->fill_lock)
 613                 return;
 614
 615         pool->fill_lock = true;
 616
 617         /* If allocation request is small and there are not enough
 618          * pages in a pool we fill the pool up first. */
 619         if (count < _manager->options.small
 620                 && count > pool->npages) {
 621                 struct pglist new_pages;
 622                 unsigned alloc_size = _manager->options.alloc_size;
 623
 624                 /**
 625                  * Can't change page caching if in irqsave context. We have to
 626                  * drop the pool->lock.
 627                  */
 628                 mtx_unlock(&pool->lock);
 629
 630                 TAILQ_INIT(&new_pages);
 631                 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
 632                     ttm_flags, cstate, alloc_size);
 633                 mtx_lock(&pool->lock);
 634
 635                 if (!r) {
 636                         TAILQ_CONCAT(&pool->list, &new_pages, plinks.q);
 637                         ++pool->nrefills;
 638                         pool->npages += alloc_size;
 639                 } else {
 640                         printf("[TTM] Failed to fill pool (%p)\n", pool);
 641                         /* If we have any pages left put them to the pool. */
 642                         TAILQ_FOREACH(p, &pool->list, plinks.q) {
 643                                 ++cpages;
 644                         }
 645                         TAILQ_CONCAT(&pool->list, &new_pages, plinks.q);
 646                         pool->npages += cpages;
 647                 }
 648
 649         }
 650         pool->fill_lock = false;
 651 }
 652
 653 /**
 654  * Cut 'count' number of pages from the pool and put them on the return list.
 655  *
 656  * @return count of pages still required to fulfill the request.
 657  */
 658 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 659                                         struct pglist *pages,
 660                                         int ttm_flags,
 661                                         enum ttm_caching_state cstate,
 662                                         unsigned count)
 663 {
 664         vm_page_t p;
 665         unsigned i;
 666
 667         mtx_lock(&pool->lock);
 668         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
 669
 670         if (count >= pool->npages) {
 671                 /* take all pages from the pool */
 672                 TAILQ_CONCAT(pages, &pool->list, plinks.q);
 673                 count -= pool->npages;
 674                 pool->npages = 0;
 675                 goto out;
 676         }
 677         for (i = 0; i < count; i++) {
 678                 p = TAILQ_FIRST(&pool->list);
 679                 TAILQ_REMOVE(&pool->list, p, plinks.q);
 680                 TAILQ_INSERT_TAIL(pages, p, plinks.q);
 681         }
 682         pool->npages -= count;
 683         count = 0;
 684 out:
 685         mtx_unlock(&pool->lock);
 686         return count;
 687 }
 688
 689 /* Put all pages in pages list to correct pool to wait for reuse */
 690 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
 691                           enum ttm_caching_state cstate)
 692 {
 693         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 694         unsigned i;
 695
 696         if (pool == NULL) {
 697                 /* No pool for this memory type so free the pages */
 698                 for (i = 0; i < npages; i++) {
 699                         if (pages[i]) {
 700                                 ttm_vm_page_free(pages[i]);
 701                                 pages[i] = NULL;
 702                         }
 703                 }
 704                 return;
 705         }
 706
 707         mtx_lock(&pool->lock);
 708         for (i = 0; i < npages; i++) {
 709                 if (pages[i]) {
 710                         TAILQ_INSERT_TAIL(&pool->list, pages[i], plinks.q);
 711                         pages[i] = NULL;
 712                         pool->npages++;
 713                 }
 714         }
 715         /* Check that we don't go over the pool limit */
 716         npages = 0;
 717         if (pool->npages > _manager->options.max_size) {
 718                 npages = pool->npages - _manager->options.max_size;
 719                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 720                  * to reduce calls to set_memory_wb */
 721                 if (npages < NUM_PAGES_TO_ALLOC)
 722                         npages = NUM_PAGES_TO_ALLOC;
 723         }
 724         mtx_unlock(&pool->lock);
 725         if (npages)
 726                 ttm_page_pool_free(pool, npages);
 727 }
 728
 729 /*
 730  * On success pages list will hold count number of correctly
 731  * cached pages.
 732  */
 733 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
 734                          enum ttm_caching_state cstate)
 735 {
 736         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 737         struct pglist plist;
 738         vm_page_t p = NULL;
 739         int gfp_flags;
 740         unsigned count;
 741         int r;
 742
 743         /* No pool for cached pages */
 744         if (pool == NULL) {
 745                 for (r = 0; r < npages; ++r) {
 746                         p = ttm_vm_page_alloc(flags, cstate);
 747                         if (!p) {
 748                                 printf("[TTM] Unable to allocate page\n");
 749                                 return -ENOMEM;
 750                         }
 751                         pages[r] = p;
 752                 }
 753                 return 0;
 754         }
 755
 756         /* combine zero flag to pool flags */
 757         gfp_flags = flags | pool->ttm_page_alloc_flags;
 758
 759         /* First we take pages from the pool */
 760         TAILQ_INIT(&plist);
 761         npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
 762         count = 0;
 763         TAILQ_FOREACH(p, &plist, plinks.q) {
 764                 pages[count++] = p;
 765         }
 766
 767         /* clear the pages coming from the pool if requested */
 768         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 769                 TAILQ_FOREACH(p, &plist, plinks.q) {
 770                         pmap_zero_page(p);
 771                 }
 772         }
 773
 774         /* If pool didn't have enough pages allocate new one. */
 775         if (npages > 0) {
 776                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 777                  * multiple requests in parallel.
 778                  **/
 779                 TAILQ_INIT(&plist);
 780                 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
 781                     npages);
 782                 TAILQ_FOREACH(p, &plist, plinks.q) {
 783                         pages[count++] = p;
 784                 }
 785                 if (r) {
 786                         /* If there is any pages in the list put them back to
 787                          * the pool. */
 788                         printf("[TTM] Failed to allocate extra pages for large request\n");
 789                         ttm_put_pages(pages, count, flags, cstate);
 790                         return r;
 791                 }
 792         }
 793
 794         return 0;
 795 }
 796
 797 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 798                                       char *name)
 799 {
 800         mtx_init(&pool->lock, "ttmpool", NULL, MTX_DEF);
 801         pool->fill_lock = false;
 802         TAILQ_INIT(&pool->list);
 803         pool->npages = pool->nfrees = 0;
 804         pool->ttm_page_alloc_flags = flags;
 805         pool->name = name;
 806 }
 807
 808 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 809 {
 810
 811         if (_manager != NULL)
 812                 printf("[TTM] manager != NULL\n");
 813         printf("[TTM] Initializing pool allocator\n");
 814
 815         _manager = malloc(sizeof(*_manager), M_TTM_POOLMGR, M_WAITOK | M_ZERO);
 816
 817         ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
 818         ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
 819         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 820             TTM_PAGE_FLAG_DMA32, "wc dma");
 821         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 822             TTM_PAGE_FLAG_DMA32, "uc dma");
 823
 824         _manager->options.max_size = max_pages;
 825         _manager->options.small = SMALL_ALLOCATION;
 826         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 827
 828         refcount_init(&_manager->kobj_ref, 1);
 829         ttm_pool_mm_shrink_init(_manager);
 830
 831         return 0;
 832 }
 833
 834 void ttm_page_alloc_fini(void)
 835 {
 836         int i;
 837
 838         printf("[TTM] Finalizing pool allocator\n");
 839         ttm_pool_mm_shrink_fini(_manager);
 840
 841         for (i = 0; i < NUM_POOLS; ++i)
 842                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 843
 844         if (refcount_release(&_manager->kobj_ref))
 845                 ttm_pool_kobj_release(_manager);
 846         _manager = NULL;
 847 }
 848
 849 int ttm_pool_populate(struct ttm_tt *ttm)
 850 {
 851         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 852         unsigned i;
 853         int ret;
 854
 855         if (ttm->state != tt_unpopulated)
 856                 return 0;
 857
 858         for (i = 0; i < ttm->num_pages; ++i) {
 859                 ret = ttm_get_pages(&ttm->pages[i], 1,
 860                                     ttm->page_flags,
 861                                     ttm->caching_state);
 862                 if (ret != 0) {
 863                         ttm_pool_unpopulate(ttm);
 864                         return -ENOMEM;
 865                 }
 866
 867                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 868                                                 false, false);
 869                 if (unlikely(ret != 0)) {
 870                         ttm_pool_unpopulate(ttm);
 871                         return -ENOMEM;
 872                 }
 873         }
 874
 875         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 876                 ret = ttm_tt_swapin(ttm);
 877                 if (unlikely(ret != 0)) {
 878                         ttm_pool_unpopulate(ttm);
 879                         return ret;
 880                 }
 881         }
 882
 883         ttm->state = tt_unbound;
 884         return 0;
 885 }
 886
 887 void ttm_pool_unpopulate(struct ttm_tt *ttm)
 888 {
 889         unsigned i;
 890
 891         for (i = 0; i < ttm->num_pages; ++i) {
 892                 if (ttm->pages[i]) {
 893                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 894                                                  ttm->pages[i]);
 895                         ttm_put_pages(&ttm->pages[i], 1,
 896                                       ttm->page_flags,
 897                                       ttm->caching_state);
 898                 }
 899         }
 900         ttm->state = tt_unpopulated;
 901 }
 902
 903 #if 0
 904 /* XXXKIB sysctl */
 905 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 906 {
 907         struct ttm_page_pool *p;
 908         unsigned i;
 909         char *h[] = {"pool", "refills", "pages freed", "size"};
 910         if (!_manager) {
 911                 seq_printf(m, "No pool allocator running.\n");
 912                 return 0;
 913         }
 914         seq_printf(m, "%6s %12s %13s %8s\n",
 915                         h[0], h[1], h[2], h[3]);
 916         for (i = 0; i < NUM_POOLS; ++i) {
 917                 p = &_manager->pools[i];
 918
 919                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 920                                 p->name, p->nrefills,
 921                                 p->nfrees, p->npages);
 922         }
 923         return 0;
 924 }
 925 #endif