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