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  * $FreeBSD: head/sys/dev/drm2/ttm/ttm_page_alloc.c 247849 2013-03-05 16:15:34Z kib $
  35  */
  36
  37 /* simple list based uncached page pool
  38  * - Pool collects resently freed pages for reuse
  39  * - Use page->lru to keep a free list
  40  * - doesn't track currently in use pages
  41  */
  42
  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
  48 #ifdef TTM_HAS_AGP
  49 #include <asm/agp.h>
  50 #endif
  51
  52 #define VM_ALLOC_DMA32  VM_ALLOC_RESERVED1
  53
  54 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(vm_page_t))
  55 #define SMALL_ALLOCATION                16
  56 #define FREE_ALL_PAGES                  (~0U)
  57 /* times are in msecs */
  58 #define PAGE_FREE_INTERVAL              1000
  59
  60 /**
  61  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  62  *
  63  * @lock: Protects the shared pool from concurrnet access. Must be used with
  64  * irqsave/irqrestore variants because pool allocator maybe called from
  65  * delayed work.
  66  * @fill_lock: Prevent concurrent calls to fill.
  67  * @list: Pool of free uc/wc pages for fast reuse.
  68  * @gfp_flags: Flags to pass for alloc_page.
  69  * @npages: Number of pages in pool.
  70  */
  71 struct ttm_page_pool {
  72         struct mtx              lock;
  73         bool                    fill_lock;
  74         bool                    dma32;
  75         struct pglist           list;
  76         int                     ttm_page_alloc_flags;
  77         unsigned                npages;
  78         char                    *name;
  79         unsigned long           nfrees;
  80         unsigned long           nrefills;
  81 };
  82
  83 /**
  84  * Limits for the pool. They are handled without locks because only place where
  85  * they may change is in sysfs store. They won't have immediate effect anyway
  86  * so forcing serialization to access them is pointless.
  87  */
  88
  89 struct ttm_pool_opts {
  90         unsigned        alloc_size;
  91         unsigned        max_size;
  92         unsigned        small;
  93 };
  94
  95 #define NUM_POOLS 4
  96
  97 /**
  98  * struct ttm_pool_manager - Holds memory pools for fst allocation
  99  *
 100  * Manager is read only object for pool code so it doesn't need locking.
 101  *
 102  * @free_interval: minimum number of jiffies between freeing pages from pool.
 103  * @page_alloc_inited: reference counting for pool allocation.
 104  * @work: Work that is used to shrink the pool. Work is only run when there is
 105  * some pages to free.
 106  * @small_allocation: Limit in number of pages what is small allocation.
 107  *
 108  * @pools: All pool objects in use.
 109  **/
 110 struct ttm_pool_manager {
 111         unsigned int kobj_ref;
 112         eventhandler_tag lowmem_handler;
 113         struct ttm_pool_opts    options;
 114
 115         union {
 116                 struct ttm_page_pool    u_pools[NUM_POOLS];
 117                 struct _utag {
 118                         struct ttm_page_pool    u_wc_pool;
 119                         struct ttm_page_pool    u_uc_pool;
 120                         struct ttm_page_pool    u_wc_pool_dma32;
 121                         struct ttm_page_pool    u_uc_pool_dma32;
 122                 } _ut;
 123         } _u;
 124 };
 125
 126 #define pools _u.u_pools
 127 #define wc_pool _u._ut.u_wc_pool
 128 #define uc_pool _u._ut.u_uc_pool
 129 #define wc_pool_dma32 _u._ut.u_wc_pool_dma32
 130 #define uc_pool_dma32 _u._ut.u_uc_pool_dma32
 131
 132 MALLOC_DEFINE(M_TTM_POOLMGR, "ttm_poolmgr", "TTM Pool Manager");
 133
 134 static void
 135 ttm_vm_page_free(vm_page_t m)
 136 {
 137
 138         KASSERT(m->object == NULL, ("ttm page %p is owned", m));
 139         KASSERT(m->wire_count == 1, ("ttm lost wire %p", m));
 140         KASSERT((m->flags & PG_FICTITIOUS) != 0, ("ttm lost fictitious %p", m));
 141         KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("ttm got unmanaged %p", m));
 142         m->flags &= ~PG_FICTITIOUS;
 143         m->oflags |= VPO_UNMANAGED;
 144         vm_page_unwire(m, 0);
 145         vm_page_free(m);
 146 }
 147
 148 static vm_memattr_t
 149 ttm_caching_state_to_vm(enum ttm_caching_state cstate)
 150 {
 151
 152         switch (cstate) {
 153         case tt_uncached:
 154                 return (VM_MEMATTR_UNCACHEABLE);
 155         case tt_wc:
 156                 return (VM_MEMATTR_WRITE_COMBINING);
 157         case tt_cached:
 158                 return (VM_MEMATTR_WRITE_BACK);
 159         }
 160         panic("caching state %d\n", cstate);
 161 }
 162
 163 static void ttm_pool_kobj_release(struct ttm_pool_manager *m)
 164 {
 165
 166         free(m, M_TTM_POOLMGR);
 167 }
 168
 169 #if 0
 170 /* XXXKIB sysctl */
 171 static ssize_t ttm_pool_store(struct ttm_pool_manager *m,
 172                 struct attribute *attr, const char *buffer, size_t size)
 173 {
 174         int chars;
 175         unsigned val;
 176         chars = sscanf(buffer, "%u", &val);
 177         if (chars == 0)
 178                 return size;
 179
 180         /* Convert kb to number of pages */
 181         val = val / (PAGE_SIZE >> 10);
 182
 183         if (attr == &ttm_page_pool_max)
 184                 m->options.max_size = val;
 185         else if (attr == &ttm_page_pool_small)
 186                 m->options.small = val;
 187         else if (attr == &ttm_page_pool_alloc_size) {
 188                 if (val > NUM_PAGES_TO_ALLOC*8) {
 189                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 190                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 191                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 192                         return size;
 193                 } else if (val > NUM_PAGES_TO_ALLOC) {
 194                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 195                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 196                 }
 197                 m->options.alloc_size = val;
 198         }
 199
 200         return size;
 201 }
 202
 203 static ssize_t ttm_pool_show(struct ttm_pool_manager *m,
 204                 struct attribute *attr, char *buffer)
 205 {
 206         unsigned val = 0;
 207
 208         if (attr == &ttm_page_pool_max)
 209                 val = m->options.max_size;
 210         else if (attr == &ttm_page_pool_small)
 211                 val = m->options.small;
 212         else if (attr == &ttm_page_pool_alloc_size)
 213                 val = m->options.alloc_size;
 214
 215         val = val * (PAGE_SIZE >> 10);
 216
 217         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 218 }
 219 #endif
 220
 221 static struct ttm_pool_manager *_manager;
 222
 223 static int set_pages_array_wb(vm_page_t *pages, int addrinarray)
 224 {
 225         vm_page_t m;
 226         int i;
 227
 228         for (i = 0; i < addrinarray; i++) {
 229                 m = pages[i];
 230 #ifdef TTM_HAS_AGP
 231                 unmap_page_from_agp(m);
 232 #endif
 233                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_BACK);
 234         }
 235         return 0;
 236 }
 237
 238 static int set_pages_array_wc(vm_page_t *pages, int addrinarray)
 239 {
 240         vm_page_t m;
 241         int i;
 242
 243         for (i = 0; i < addrinarray; i++) {
 244                 m = pages[i];
 245 #ifdef TTM_HAS_AGP
 246                 map_page_into_agp(pages[i]);
 247 #endif
 248                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_COMBINING);
 249         }
 250         return 0;
 251 }
 252
 253 static int set_pages_array_uc(vm_page_t *pages, int addrinarray)
 254 {
 255         vm_page_t m;
 256         int i;
 257
 258         for (i = 0; i < addrinarray; i++) {
 259                 m = pages[i];
 260 #ifdef TTM_HAS_AGP
 261                 map_page_into_agp(pages[i]);
 262 #endif
 263                 pmap_page_set_memattr(m, VM_MEMATTR_UNCACHEABLE);
 264         }
 265         return 0;
 266 }
 267
 268 /**
 269  * Select the right pool or requested caching state and ttm flags. */
 270 static struct ttm_page_pool *ttm_get_pool(int flags,
 271                 enum ttm_caching_state cstate)
 272 {
 273         int pool_index;
 274
 275         if (cstate == tt_cached)
 276                 return NULL;
 277
 278         if (cstate == tt_wc)
 279                 pool_index = 0x0;
 280         else
 281                 pool_index = 0x1;
 282
 283         if (flags & TTM_PAGE_FLAG_DMA32)
 284                 pool_index |= 0x2;
 285
 286         return &_manager->pools[pool_index];
 287 }
 288
 289 /* set memory back to wb and free the pages. */
 290 static void ttm_pages_put(vm_page_t *pages, unsigned npages)
 291 {
 292         unsigned i;
 293
 294         /* Our VM handles vm memattr automatically on the page free. */
 295         if (set_pages_array_wb(pages, npages))
 296                 printf("[TTM] Failed to set %d pages to wb!\n", npages);
 297         for (i = 0; i < npages; ++i)
 298                 ttm_vm_page_free(pages[i]);
 299 }
 300
 301 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 302                 unsigned freed_pages)
 303 {
 304         pool->npages -= freed_pages;
 305         pool->nfrees += freed_pages;
 306 }
 307
 308 /**
 309  * Free pages from pool.
 310  *
 311  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 312  * number of pages in one go.
 313  *
 314  * @pool: to free the pages from
 315  * @free_all: If set to true will free all pages in pool
 316  **/
 317 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 318 {
 319         vm_page_t p, p1;
 320         vm_page_t *pages_to_free;
 321         unsigned freed_pages = 0,
 322                  npages_to_free = nr_free;
 323
 324         if (NUM_PAGES_TO_ALLOC < nr_free)
 325                 npages_to_free = NUM_PAGES_TO_ALLOC;
 326
 327         pages_to_free = malloc(npages_to_free * sizeof(vm_page_t),
 328             M_TEMP, M_WAITOK | M_ZERO);
 329
 330 restart:
 331         mtx_lock(&pool->lock);
 332
 333         TAILQ_FOREACH_REVERSE_SAFE(p, &pool->list, pglist, pageq, p1) {
 334                 if (freed_pages >= npages_to_free)
 335                         break;
 336
 337                 pages_to_free[freed_pages++] = p;
 338                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 339                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 340                         /* remove range of pages from the pool */
 341                         TAILQ_REMOVE(&pool->list, p, pageq);
 342
 343                         ttm_pool_update_free_locked(pool, freed_pages);
 344                         /**
 345                          * Because changing page caching is costly
 346                          * we unlock the pool to prevent stalling.
 347                          */
 348                         mtx_unlock(&pool->lock);
 349
 350                         ttm_pages_put(pages_to_free, freed_pages);
 351                         if (likely(nr_free != FREE_ALL_PAGES))
 352                                 nr_free -= freed_pages;
 353
 354                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 355                                 npages_to_free = nr_free;
 356                         else
 357                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 358
 359                         freed_pages = 0;
 360
 361                         /* free all so restart the processing */
 362                         if (nr_free)
 363                                 goto restart;
 364
 365                         /* Not allowed to fall through or break because
 366                          * following context is inside spinlock while we are
 367                          * outside here.
 368                          */
 369                         goto out;
 370
 371                 }
 372         }
 373
 374         /* remove range of pages from the pool */
 375         if (freed_pages) {
 376                 TAILQ_REMOVE(&pool->list, p, pageq);
 377
 378                 ttm_pool_update_free_locked(pool, freed_pages);
 379                 nr_free -= freed_pages;
 380         }
 381
 382         mtx_unlock(&pool->lock);
 383
 384         if (freed_pages)
 385                 ttm_pages_put(pages_to_free, freed_pages);
 386 out:
 387         free(pages_to_free, M_TEMP);
 388         return nr_free;
 389 }
 390
 391 /* Get good estimation how many pages are free in pools */
 392 static int ttm_pool_get_num_unused_pages(void)
 393 {
 394         unsigned i;
 395         int total = 0;
 396         for (i = 0; i < NUM_POOLS; ++i)
 397                 total += _manager->pools[i].npages;
 398
 399         return total;
 400 }
 401
 402 /**
 403  * Callback for mm to request pool to reduce number of page held.
 404  */
 405 static int ttm_pool_mm_shrink(void *arg)
 406 {
 407         static unsigned int start_pool = 0;
 408         unsigned i;
 409         unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
 410         struct ttm_page_pool *pool;
 411         int shrink_pages = 100; /* XXXKIB */
 412
 413         pool_offset = pool_offset % NUM_POOLS;
 414         /* select start pool in round robin fashion */
 415         for (i = 0; i < NUM_POOLS; ++i) {
 416                 unsigned nr_free = shrink_pages;
 417                 if (shrink_pages == 0)
 418                         break;
 419                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 420                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 421         }
 422         /* return estimated number of unused pages in pool */
 423         return ttm_pool_get_num_unused_pages();
 424 }
 425
 426 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 427 {
 428
 429         manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
 430             ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
 431 }
 432
 433 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 434 {
 435
 436         EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
 437 }
 438
 439 static int ttm_set_pages_caching(vm_page_t *pages,
 440                 enum ttm_caching_state cstate, unsigned cpages)
 441 {
 442         int r = 0;
 443         /* Set page caching */
 444         switch (cstate) {
 445         case tt_uncached:
 446                 r = set_pages_array_uc(pages, cpages);
 447                 if (r)
 448                         printf("[TTM] Failed to set %d pages to uc!\n", cpages);
 449                 break;
 450         case tt_wc:
 451                 r = set_pages_array_wc(pages, cpages);
 452                 if (r)
 453                         printf("[TTM] Failed to set %d pages to wc!\n", cpages);
 454                 break;
 455         default:
 456                 break;
 457         }
 458         return r;
 459 }
 460
 461 /**
 462  * Free pages the pages that failed to change the caching state. If there is
 463  * any pages that have changed their caching state already put them to the
 464  * pool.
 465  */
 466 static void ttm_handle_caching_state_failure(struct pglist *pages,
 467                 int ttm_flags, enum ttm_caching_state cstate,
 468                 vm_page_t *failed_pages, unsigned cpages)
 469 {
 470         unsigned i;
 471         /* Failed pages have to be freed */
 472         for (i = 0; i < cpages; ++i) {
 473                 TAILQ_REMOVE(pages, failed_pages[i], pageq);
 474                 ttm_vm_page_free(failed_pages[i]);
 475         }
 476 }
 477
 478 /**
 479  * Allocate new pages with correct caching.
 480  *
 481  * This function is reentrant if caller updates count depending on number of
 482  * pages returned in pages array.
 483  */
 484 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
 485                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 486 {
 487         vm_page_t *caching_array;
 488         vm_page_t p;
 489         int r = 0;
 490         unsigned i, cpages, aflags;
 491         unsigned max_cpages = min(count,
 492                         (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
 493
 494         aflags = VM_ALLOC_NORMAL | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
 495             ((ttm_alloc_flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ?
 496             VM_ALLOC_ZERO : 0);
 497
 498         /* allocate array for page caching change */
 499         caching_array = malloc(max_cpages * sizeof(vm_page_t), M_TEMP,
 500             M_WAITOK | M_ZERO);
 501
 502         for (i = 0, cpages = 0; i < count; ++i) {
 503                 p = vm_page_alloc_contig(NULL, 0, aflags, 1, 0,
 504                     (ttm_alloc_flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 505                     VM_MAX_ADDRESS, PAGE_SIZE, 0,
 506                     ttm_caching_state_to_vm(cstate));
 507                 if (!p) {
 508                         printf("[TTM] Unable to get page %u\n", i);
 509
 510                         /* store already allocated pages in the pool after
 511                          * setting the caching state */
 512                         if (cpages) {
 513                                 r = ttm_set_pages_caching(caching_array,
 514                                                           cstate, cpages);
 515                                 if (r)
 516                                         ttm_handle_caching_state_failure(pages,
 517                                                 ttm_flags, cstate,
 518                                                 caching_array, cpages);
 519                         }
 520                         r = -ENOMEM;
 521                         goto out;
 522                 }
 523                 p->oflags &= ~VPO_UNMANAGED;
 524                 p->flags |= PG_FICTITIOUS;
 525
 526 #ifdef CONFIG_HIGHMEM /* KIB: nop */
 527                 /* gfp flags of highmem page should never be dma32 so we
 528                  * we should be fine in such case
 529                  */
 530                 if (!PageHighMem(p))
 531 #endif
 532                 {
 533                         caching_array[cpages++] = p;
 534                         if (cpages == max_cpages) {
 535
 536                                 r = ttm_set_pages_caching(caching_array,
 537                                                 cstate, cpages);
 538                                 if (r) {
 539                                         ttm_handle_caching_state_failure(pages,
 540                                                 ttm_flags, cstate,
 541                                                 caching_array, cpages);
 542                                         goto out;
 543                                 }
 544                                 cpages = 0;
 545                         }
 546                 }
 547
 548                 TAILQ_INSERT_HEAD(pages, p, pageq);
 549         }
 550
 551         if (cpages) {
 552                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 553                 if (r)
 554                         ttm_handle_caching_state_failure(pages,
 555                                         ttm_flags, cstate,
 556                                         caching_array, cpages);
 557         }
 558 out:
 559         free(caching_array, M_TEMP);
 560
 561         return r;
 562 }
 563
 564 /**
 565  * Fill the given pool if there aren't enough pages and the requested number of
 566  * pages is small.
 567  */
 568 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 569     int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 570 {
 571         vm_page_t p;
 572         int r;
 573         unsigned cpages = 0;
 574         /**
 575          * Only allow one pool fill operation at a time.
 576          * If pool doesn't have enough pages for the allocation new pages are
 577          * allocated from outside of pool.
 578          */
 579         if (pool->fill_lock)
 580                 return;
 581
 582         pool->fill_lock = true;
 583
 584         /* If allocation request is small and there are not enough
 585          * pages in a pool we fill the pool up first. */
 586         if (count < _manager->options.small
 587                 && count > pool->npages) {
 588                 struct pglist new_pages;
 589                 unsigned alloc_size = _manager->options.alloc_size;
 590
 591                 /**
 592                  * Can't change page caching if in irqsave context. We have to
 593                  * drop the pool->lock.
 594                  */
 595                 mtx_unlock(&pool->lock);
 596
 597                 TAILQ_INIT(&new_pages);
 598                 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
 599                     ttm_flags, cstate, alloc_size);
 600                 mtx_lock(&pool->lock);
 601
 602                 if (!r) {
 603                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 604                         ++pool->nrefills;
 605                         pool->npages += alloc_size;
 606                 } else {
 607                         printf("[TTM] Failed to fill pool (%p)\n", pool);
 608                         /* If we have any pages left put them to the pool. */
 609                         TAILQ_FOREACH(p, &pool->list, pageq) {
 610                                 ++cpages;
 611                         }
 612                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 613                         pool->npages += cpages;
 614                 }
 615
 616         }
 617         pool->fill_lock = false;
 618 }
 619
 620 /**
 621  * Cut 'count' number of pages from the pool and put them on the return list.
 622  *
 623  * @return count of pages still required to fulfill the request.
 624  */
 625 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 626                                         struct pglist *pages,
 627                                         int ttm_flags,
 628                                         enum ttm_caching_state cstate,
 629                                         unsigned count)
 630 {
 631         vm_page_t p;
 632         unsigned i;
 633
 634         mtx_lock(&pool->lock);
 635         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
 636
 637         if (count >= pool->npages) {
 638                 /* take all pages from the pool */
 639                 TAILQ_CONCAT(pages, &pool->list, pageq);
 640                 count -= pool->npages;
 641                 pool->npages = 0;
 642                 goto out;
 643         }
 644         for (i = 0; i < count; i++) {
 645                 p = TAILQ_FIRST(&pool->list);
 646                 TAILQ_REMOVE(&pool->list, p, pageq);
 647                 TAILQ_INSERT_TAIL(pages, p, pageq);
 648         }
 649         pool->npages -= count;
 650         count = 0;
 651 out:
 652         mtx_unlock(&pool->lock);
 653         return count;
 654 }
 655
 656 /* Put all pages in pages list to correct pool to wait for reuse */
 657 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
 658                           enum ttm_caching_state cstate)
 659 {
 660         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 661         unsigned i;
 662
 663         if (pool == NULL) {
 664                 /* No pool for this memory type so free the pages */
 665                 for (i = 0; i < npages; i++) {
 666                         if (pages[i]) {
 667                                 ttm_vm_page_free(pages[i]);
 668                                 pages[i] = NULL;
 669                         }
 670                 }
 671                 return;
 672         }
 673
 674         mtx_lock(&pool->lock);
 675         for (i = 0; i < npages; i++) {
 676                 if (pages[i]) {
 677                         TAILQ_INSERT_TAIL(&pool->list, pages[i], pageq);
 678                         pages[i] = NULL;
 679                         pool->npages++;
 680                 }
 681         }
 682         /* Check that we don't go over the pool limit */
 683         npages = 0;
 684         if (pool->npages > _manager->options.max_size) {
 685                 npages = pool->npages - _manager->options.max_size;
 686                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 687                  * to reduce calls to set_memory_wb */
 688                 if (npages < NUM_PAGES_TO_ALLOC)
 689                         npages = NUM_PAGES_TO_ALLOC;
 690         }
 691         mtx_unlock(&pool->lock);
 692         if (npages)
 693                 ttm_page_pool_free(pool, npages);
 694 }
 695
 696 /*
 697  * On success pages list will hold count number of correctly
 698  * cached pages.
 699  */
 700 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
 701                          enum ttm_caching_state cstate)
 702 {
 703         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 704         struct pglist plist;
 705         vm_page_t p = NULL;
 706         int gfp_flags, aflags;
 707         unsigned count;
 708         int r;
 709
 710         aflags = VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED |
 711             ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ? VM_ALLOC_ZERO : 0);
 712
 713         /* No pool for cached pages */
 714         if (pool == NULL) {
 715                 for (r = 0; r < npages; ++r) {
 716                         p = vm_page_alloc_contig(NULL, 0, aflags, 1, 0,
 717                             (flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 718                             VM_MAX_ADDRESS, PAGE_SIZE,
 719                             0, ttm_caching_state_to_vm(cstate));
 720                         if (!p) {
 721                                 printf("[TTM] Unable to allocate page\n");
 722                                 return -ENOMEM;
 723                         }
 724                         p->oflags &= ~VPO_UNMANAGED;
 725                         p->flags |= PG_FICTITIOUS;
 726                         pages[r] = p;
 727                 }
 728                 return 0;
 729         }
 730
 731         /* combine zero flag to pool flags */
 732         gfp_flags = flags | pool->ttm_page_alloc_flags;
 733
 734         /* First we take pages from the pool */
 735         TAILQ_INIT(&plist);
 736         npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
 737         count = 0;
 738         TAILQ_FOREACH(p, &plist, pageq) {
 739                 pages[count++] = p;
 740         }
 741
 742         /* clear the pages coming from the pool if requested */
 743         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 744                 TAILQ_FOREACH(p, &plist, pageq) {
 745                         pmap_zero_page(p);
 746                 }
 747         }
 748
 749         /* If pool didn't have enough pages allocate new one. */
 750         if (npages > 0) {
 751                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 752                  * multiple requests in parallel.
 753                  **/
 754                 TAILQ_INIT(&plist);
 755                 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
 756                     npages);
 757                 TAILQ_FOREACH(p, &plist, pageq) {
 758                         pages[count++] = p;
 759                 }
 760                 if (r) {
 761                         /* If there is any pages in the list put them back to
 762                          * the pool. */
 763                         printf("[TTM] Failed to allocate extra pages for large request\n");
 764                         ttm_put_pages(pages, count, flags, cstate);
 765                         return r;
 766                 }
 767         }
 768
 769         return 0;
 770 }
 771
 772 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 773                                       char *name)
 774 {
 775         mtx_init(&pool->lock, "ttmpool", NULL, MTX_DEF);
 776         pool->fill_lock = false;
 777         TAILQ_INIT(&pool->list);
 778         pool->npages = pool->nfrees = 0;
 779         pool->ttm_page_alloc_flags = flags;
 780         pool->name = name;
 781 }
 782
 783 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 784 {
 785
 786         if (_manager != NULL)
 787                 printf("[TTM] manager != NULL\n");
 788         printf("[TTM] Initializing pool allocator\n");
 789
 790         _manager = malloc(sizeof(*_manager), M_TTM_POOLMGR, M_WAITOK | M_ZERO);
 791
 792         ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
 793         ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
 794         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 795             TTM_PAGE_FLAG_DMA32, "wc dma");
 796         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 797             TTM_PAGE_FLAG_DMA32, "uc dma");
 798
 799         _manager->options.max_size = max_pages;
 800         _manager->options.small = SMALL_ALLOCATION;
 801         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 802
 803         refcount_init(&_manager->kobj_ref, 1);
 804         ttm_pool_mm_shrink_init(_manager);
 805
 806         return 0;
 807 }
 808
 809 void ttm_page_alloc_fini(void)
 810 {
 811         int i;
 812
 813         printf("[TTM] Finalizing pool allocator\n");
 814         ttm_pool_mm_shrink_fini(_manager);
 815
 816         for (i = 0; i < NUM_POOLS; ++i)
 817                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 818
 819         if (refcount_release(&_manager->kobj_ref))
 820                 ttm_pool_kobj_release(_manager);
 821         _manager = NULL;
 822 }
 823
 824 int ttm_pool_populate(struct ttm_tt *ttm)
 825 {
 826         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 827         unsigned i;
 828         int ret;
 829
 830         if (ttm->state != tt_unpopulated)
 831                 return 0;
 832
 833         for (i = 0; i < ttm->num_pages; ++i) {
 834                 ret = ttm_get_pages(&ttm->pages[i], 1,
 835                                     ttm->page_flags,
 836                                     ttm->caching_state);
 837                 if (ret != 0) {
 838                         ttm_pool_unpopulate(ttm);
 839                         return -ENOMEM;
 840                 }
 841
 842                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 843                                                 false, false);
 844                 if (unlikely(ret != 0)) {
 845                         ttm_pool_unpopulate(ttm);
 846                         return -ENOMEM;
 847                 }
 848         }
 849
 850         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 851                 ret = ttm_tt_swapin(ttm);
 852                 if (unlikely(ret != 0)) {
 853                         ttm_pool_unpopulate(ttm);
 854                         return ret;
 855                 }
 856         }
 857
 858         ttm->state = tt_unbound;
 859         return 0;
 860 }
 861
 862 void ttm_pool_unpopulate(struct ttm_tt *ttm)
 863 {
 864         unsigned i;
 865
 866         for (i = 0; i < ttm->num_pages; ++i) {
 867                 if (ttm->pages[i]) {
 868                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 869                                                  ttm->pages[i]);
 870                         ttm_put_pages(&ttm->pages[i], 1,
 871                                       ttm->page_flags,
 872                                       ttm->caching_state);
 873                 }
 874         }
 875         ttm->state = tt_unpopulated;
 876 }
 877
 878 #if 0
 879 /* XXXKIB sysctl */
 880 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 881 {
 882         struct ttm_page_pool *p;
 883         unsigned i;
 884         char *h[] = {"pool", "refills", "pages freed", "size"};
 885         if (!_manager) {
 886                 seq_printf(m, "No pool allocator running.\n");
 887                 return 0;
 888         }
 889         seq_printf(m, "%6s %12s %13s %8s\n",
 890                         h[0], h[1], h[2], h[3]);
 891         for (i = 0; i < NUM_POOLS; ++i) {
 892                 p = &_manager->pools[i];
 893
 894                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 895                                 p->name, p->nrefills,
 896                                 p->nfrees, p->npages);
 897         }
 898         return 0;
 899 }
 900 #endif