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 #include <sys/eventhandler.h>
  44
  45 #include <dev/drm2/drmP.h>
  46 #include <dev/drm2/ttm/ttm_bo_driver.h>
  47 #include <dev/drm2/ttm/ttm_page_alloc.h>
  48
  49 #ifdef TTM_HAS_AGP
  50 #include <asm/agp.h>
  51 #endif
  52
  53 #define VM_ALLOC_DMA32  VM_ALLOC_RESERVED1
  54
  55 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(vm_page_t))
  56 #define SMALL_ALLOCATION                16
  57 #define FREE_ALL_PAGES                  (~0U)
  58 /* times are in msecs */
  59 #define PAGE_FREE_INTERVAL              1000
  60
  61 /**
  62  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  63  *
  64  * @lock: Protects the shared pool from concurrnet access. Must be used with
  65  * irqsave/irqrestore variants because pool allocator maybe called from
  66  * delayed work.
  67  * @fill_lock: Prevent concurrent calls to fill.
  68  * @list: Pool of free uc/wc pages for fast reuse.
  69  * @gfp_flags: Flags to pass for alloc_page.
  70  * @npages: Number of pages in pool.
  71  */
  72 struct ttm_page_pool {
  73         struct lock             lock;
  74         bool                    fill_lock;
  75         bool                    dma32;
  76         struct pglist           list;
  77         int                     ttm_page_alloc_flags;
  78         unsigned                npages;
  79         char                    *name;
  80         unsigned long           nfrees;
  81         unsigned long           nrefills;
  82 };
  83
  84 /**
  85  * Limits for the pool. They are handled without locks because only place where
  86  * they may change is in sysfs store. They won't have immediate effect anyway
  87  * so forcing serialization to access them is pointless.
  88  */
  89
  90 struct ttm_pool_opts {
  91         unsigned        alloc_size;
  92         unsigned        max_size;
  93         unsigned        small;
  94 };
  95
  96 #define NUM_POOLS 4
  97
  98 /**
  99  * struct ttm_pool_manager - Holds memory pools for fst allocation
 100  *
 101  * Manager is read only object for pool code so it doesn't need locking.
 102  *
 103  * @free_interval: minimum number of jiffies between freeing pages from pool.
 104  * @page_alloc_inited: reference counting for pool allocation.
 105  * @work: Work that is used to shrink the pool. Work is only run when there is
 106  * some pages to free.
 107  * @small_allocation: Limit in number of pages what is small allocation.
 108  *
 109  * @pools: All pool objects in use.
 110  **/
 111 struct ttm_pool_manager {
 112         unsigned int kobj_ref;
 113         eventhandler_tag lowmem_handler;
 114         struct ttm_pool_opts    options;
 115
 116         union {
 117                 struct ttm_page_pool    u_pools[NUM_POOLS];
 118                 struct _utag {
 119                         struct ttm_page_pool    u_wc_pool;
 120                         struct ttm_page_pool    u_uc_pool;
 121                         struct ttm_page_pool    u_wc_pool_dma32;
 122                         struct ttm_page_pool    u_uc_pool_dma32;
 123                 } _ut;
 124         } _u;
 125 };
 126
 127 #define pools _u.u_pools
 128 #define wc_pool _u._ut.u_wc_pool
 129 #define uc_pool _u._ut.u_uc_pool
 130 #define wc_pool_dma32 _u._ut.u_wc_pool_dma32
 131 #define uc_pool_dma32 _u._ut.u_uc_pool_dma32
 132
 133 MALLOC_DEFINE(M_TTM_POOLMGR, "ttm_poolmgr", "TTM Pool Manager");
 134
 135 static void
 136 ttm_vm_page_free(vm_page_t m)
 137 {
 138
 139         KASSERT(m->object == NULL, ("ttm page %p is owned", m));
 140         KASSERT(m->wire_count == 1, ("ttm lost wire %p", m));
 141         KASSERT((m->flags & PG_FICTITIOUS) != 0, ("ttm lost fictitious %p", m));
 142         KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("ttm got unmanaged %p", m));
 143         m->flags &= ~PG_FICTITIOUS;
 144         m->oflags |= VPO_UNMANAGED;
 145         vm_page_unwire(m, 0);
 146         vm_page_free(m);
 147 }
 148
 149 static vm_memattr_t
 150 ttm_caching_state_to_vm(enum ttm_caching_state cstate)
 151 {
 152
 153         switch (cstate) {
 154         case tt_uncached:
 155                 return (VM_MEMATTR_UNCACHEABLE);
 156         case tt_wc:
 157                 return (VM_MEMATTR_WRITE_COMBINING);
 158         case tt_cached:
 159                 return (VM_MEMATTR_WRITE_BACK);
 160         }
 161         panic("caching state %d\n", cstate);
 162 }
 163
 164 static void ttm_pool_kobj_release(struct ttm_pool_manager *m)
 165 {
 166
 167         drm_free(m, M_TTM_POOLMGR);
 168 }
 169
 170 #if 0
 171 /* XXXKIB sysctl */
 172 static ssize_t ttm_pool_store(struct ttm_pool_manager *m,
 173                 struct attribute *attr, const char *buffer, size_t size)
 174 {
 175         int chars;
 176         unsigned val;
 177         chars = sscanf(buffer, "%u", &val);
 178         if (chars == 0)
 179                 return size;
 180
 181         /* Convert kb to number of pages */
 182         val = val / (PAGE_SIZE >> 10);
 183
 184         if (attr == &ttm_page_pool_max)
 185                 m->options.max_size = val;
 186         else if (attr == &ttm_page_pool_small)
 187                 m->options.small = val;
 188         else if (attr == &ttm_page_pool_alloc_size) {
 189                 if (val > NUM_PAGES_TO_ALLOC*8) {
 190                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 191                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 192                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 193                         return size;
 194                 } else if (val > NUM_PAGES_TO_ALLOC) {
 195                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 196                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 197                 }
 198                 m->options.alloc_size = val;
 199         }
 200
 201         return size;
 202 }
 203
 204 static ssize_t ttm_pool_show(struct ttm_pool_manager *m,
 205                 struct attribute *attr, char *buffer)
 206 {
 207         unsigned val = 0;
 208
 209         if (attr == &ttm_page_pool_max)
 210                 val = m->options.max_size;
 211         else if (attr == &ttm_page_pool_small)
 212                 val = m->options.small;
 213         else if (attr == &ttm_page_pool_alloc_size)
 214                 val = m->options.alloc_size;
 215
 216         val = val * (PAGE_SIZE >> 10);
 217
 218         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 219 }
 220 #endif
 221
 222 static struct ttm_pool_manager *_manager;
 223
 224 static int set_pages_array_wb(vm_page_t *pages, int addrinarray)
 225 {
 226         vm_page_t m;
 227         int i;
 228
 229         for (i = 0; i < addrinarray; i++) {
 230                 m = pages[i];
 231 #ifdef TTM_HAS_AGP
 232                 unmap_page_from_agp(m);
 233 #endif
 234                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_BACK);
 235         }
 236         return 0;
 237 }
 238
 239 static int set_pages_array_wc(vm_page_t *pages, int addrinarray)
 240 {
 241         vm_page_t m;
 242         int i;
 243
 244         for (i = 0; i < addrinarray; i++) {
 245                 m = pages[i];
 246 #ifdef TTM_HAS_AGP
 247                 map_page_into_agp(pages[i]);
 248 #endif
 249                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_COMBINING);
 250         }
 251         return 0;
 252 }
 253
 254 static int set_pages_array_uc(vm_page_t *pages, int addrinarray)
 255 {
 256         vm_page_t m;
 257         int i;
 258
 259         for (i = 0; i < addrinarray; i++) {
 260                 m = pages[i];
 261 #ifdef TTM_HAS_AGP
 262                 map_page_into_agp(pages[i]);
 263 #endif
 264                 pmap_page_set_memattr(m, VM_MEMATTR_UNCACHEABLE);
 265         }
 266         return 0;
 267 }
 268
 269 /**
 270  * Select the right pool or requested caching state and ttm flags. */
 271 static struct ttm_page_pool *ttm_get_pool(int flags,
 272                 enum ttm_caching_state cstate)
 273 {
 274         int pool_index;
 275
 276         if (cstate == tt_cached)
 277                 return NULL;
 278
 279         if (cstate == tt_wc)
 280                 pool_index = 0x0;
 281         else
 282                 pool_index = 0x1;
 283
 284         if (flags & TTM_PAGE_FLAG_DMA32)
 285                 pool_index |= 0x2;
 286
 287         return &_manager->pools[pool_index];
 288 }
 289
 290 /* set memory back to wb and free the pages. */
 291 static void ttm_pages_put(vm_page_t *pages, unsigned npages)
 292 {
 293         unsigned i;
 294
 295         /* Our VM handles vm memattr automatically on the page free. */
 296         if (set_pages_array_wb(pages, npages))
 297                 kprintf("[TTM] Failed to set %d pages to wb!\n", npages);
 298         for (i = 0; i < npages; ++i)
 299                 ttm_vm_page_free(pages[i]);
 300 }
 301
 302 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 303                 unsigned freed_pages)
 304 {
 305         pool->npages -= freed_pages;
 306         pool->nfrees += freed_pages;
 307 }
 308
 309 /**
 310  * Free pages from pool.
 311  *
 312  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 313  * number of pages in one go.
 314  *
 315  * @pool: to free the pages from
 316  * @free_all: If set to true will free all pages in pool
 317  **/
 318 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 319 {
 320         vm_page_t p, p1;
 321         vm_page_t *pages_to_free;
 322         unsigned freed_pages = 0,
 323                  npages_to_free = nr_free;
 324
 325         if (NUM_PAGES_TO_ALLOC < nr_free)
 326                 npages_to_free = NUM_PAGES_TO_ALLOC;
 327
 328         pages_to_free = kmalloc(npages_to_free * sizeof(vm_page_t),
 329             M_TEMP, M_WAITOK | M_ZERO);
 330
 331 restart:
 332         lockmgr(&pool->lock, LK_EXCLUSIVE);
 333
 334         TAILQ_FOREACH_REVERSE_MUTABLE(p, &pool->list, pglist, pageq, p1) {
 335                 if (freed_pages >= npages_to_free)
 336                         break;
 337
 338                 pages_to_free[freed_pages++] = p;
 339                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 340                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 341                         /* remove range of pages from the pool */
 342                         TAILQ_REMOVE(&pool->list, p, pageq);
 343
 344                         ttm_pool_update_free_locked(pool, freed_pages);
 345                         /**
 346                          * Because changing page caching is costly
 347                          * we unlock the pool to prevent stalling.
 348                          */
 349                         lockmgr(&pool->lock, LK_RELEASE);
 350
 351                         ttm_pages_put(pages_to_free, freed_pages);
 352                         if (likely(nr_free != FREE_ALL_PAGES))
 353                                 nr_free -= freed_pages;
 354
 355                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 356                                 npages_to_free = nr_free;
 357                         else
 358                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 359
 360                         freed_pages = 0;
 361
 362                         /* free all so restart the processing */
 363                         if (nr_free)
 364                                 goto restart;
 365
 366                         /* Not allowed to fall through or break because
 367                          * following context is inside spinlock while we are
 368                          * outside here.
 369                          */
 370                         goto out;
 371
 372                 }
 373         }
 374
 375         /* remove range of pages from the pool */
 376         if (freed_pages) {
 377                 TAILQ_REMOVE(&pool->list, p, pageq);
 378
 379                 ttm_pool_update_free_locked(pool, freed_pages);
 380                 nr_free -= freed_pages;
 381         }
 382
 383         lockmgr(&pool->lock, LK_RELEASE);
 384
 385         if (freed_pages)
 386                 ttm_pages_put(pages_to_free, freed_pages);
 387 out:
 388         drm_free(pages_to_free, M_TEMP);
 389         return nr_free;
 390 }
 391
 392 /* Get good estimation how many pages are free in pools */
 393 static int ttm_pool_get_num_unused_pages(void)
 394 {
 395         unsigned i;
 396         int total = 0;
 397         for (i = 0; i < NUM_POOLS; ++i)
 398                 total += _manager->pools[i].npages;
 399
 400         return total;
 401 }
 402
 403 /**
 404  * Callback for mm to request pool to reduce number of page held.
 405  */
 406 static int ttm_pool_mm_shrink(void *arg)
 407 {
 408         static unsigned int start_pool = 0;
 409         unsigned i;
 410         unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
 411         struct ttm_page_pool *pool;
 412         int shrink_pages = 100; /* XXXKIB */
 413
 414         pool_offset = pool_offset % NUM_POOLS;
 415         /* select start pool in round robin fashion */
 416         for (i = 0; i < NUM_POOLS; ++i) {
 417                 unsigned nr_free = shrink_pages;
 418                 if (shrink_pages == 0)
 419                         break;
 420                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 421                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 422         }
 423         /* return estimated number of unused pages in pool */
 424         return ttm_pool_get_num_unused_pages();
 425 }
 426
 427 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 428 {
 429
 430         manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
 431             ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
 432 }
 433
 434 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 435 {
 436
 437         EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
 438 }
 439
 440 static int ttm_set_pages_caching(vm_page_t *pages,
 441                 enum ttm_caching_state cstate, unsigned cpages)
 442 {
 443         int r = 0;
 444         /* Set page caching */
 445         switch (cstate) {
 446         case tt_uncached:
 447                 r = set_pages_array_uc(pages, cpages);
 448                 if (r)
 449                         kprintf("[TTM] Failed to set %d pages to uc!\n", cpages);
 450                 break;
 451         case tt_wc:
 452                 r = set_pages_array_wc(pages, cpages);
 453                 if (r)
 454                         kprintf("[TTM] Failed to set %d pages to wc!\n", cpages);
 455                 break;
 456         default:
 457                 break;
 458         }
 459         return r;
 460 }
 461
 462 /**
 463  * Free pages the pages that failed to change the caching state. If there is
 464  * any pages that have changed their caching state already put them to the
 465  * pool.
 466  */
 467 static void ttm_handle_caching_state_failure(struct pglist *pages,
 468                 int ttm_flags, enum ttm_caching_state cstate,
 469                 vm_page_t *failed_pages, unsigned cpages)
 470 {
 471         unsigned i;
 472         /* Failed pages have to be freed */
 473         for (i = 0; i < cpages; ++i) {
 474                 TAILQ_REMOVE(pages, failed_pages[i], pageq);
 475                 ttm_vm_page_free(failed_pages[i]);
 476         }
 477 }
 478
 479 /**
 480  * Allocate new pages with correct caching.
 481  *
 482  * This function is reentrant if caller updates count depending on number of
 483  * pages returned in pages array.
 484  */
 485 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
 486                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 487 {
 488         vm_page_t *caching_array;
 489         vm_page_t p;
 490         int r = 0;
 491         unsigned i, cpages, aflags;
 492         unsigned max_cpages = min(count,
 493                         (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
 494
 495         aflags = VM_ALLOC_NORMAL | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
 496             ((ttm_alloc_flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ?
 497             VM_ALLOC_ZERO : 0);
 498
 499         /* allocate array for page caching change */
 500         caching_array = kmalloc(max_cpages * sizeof(vm_page_t), M_TEMP,
 501             M_WAITOK | M_ZERO);
 502
 503         for (i = 0, cpages = 0; i < count; ++i) {
 504                 p = vm_page_alloc_contig(0,
 505                     (ttm_alloc_flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 506                     VM_MAX_ADDRESS, PAGE_SIZE, 0,
 507                     1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 508                 if (!p) {
 509                         kprintf("[TTM] Unable to get page %u\n", i);
 510
 511                         /* store already allocated pages in the pool after
 512                          * setting the caching state */
 513                         if (cpages) {
 514                                 r = ttm_set_pages_caching(caching_array,
 515                                                           cstate, cpages);
 516                                 if (r)
 517                                         ttm_handle_caching_state_failure(pages,
 518                                                 ttm_flags, cstate,
 519                                                 caching_array, cpages);
 520                         }
 521                         r = -ENOMEM;
 522                         goto out;
 523                 }
 524                 p->oflags &= ~VPO_UNMANAGED;
 525                 p->flags |= PG_FICTITIOUS;
 526
 527 #ifdef CONFIG_HIGHMEM /* KIB: nop */
 528                 /* gfp flags of highmem page should never be dma32 so we
 529                  * we should be fine in such case
 530                  */
 531                 if (!PageHighMem(p))
 532 #endif
 533                 {
 534                         caching_array[cpages++] = p;
 535                         if (cpages == max_cpages) {
 536
 537                                 r = ttm_set_pages_caching(caching_array,
 538                                                 cstate, cpages);
 539                                 if (r) {
 540                                         ttm_handle_caching_state_failure(pages,
 541                                                 ttm_flags, cstate,
 542                                                 caching_array, cpages);
 543                                         goto out;
 544                                 }
 545                                 cpages = 0;
 546                         }
 547                 }
 548
 549                 TAILQ_INSERT_HEAD(pages, p, pageq);
 550         }
 551
 552         if (cpages) {
 553                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 554                 if (r)
 555                         ttm_handle_caching_state_failure(pages,
 556                                         ttm_flags, cstate,
 557                                         caching_array, cpages);
 558         }
 559 out:
 560         drm_free(caching_array, M_TEMP);
 561
 562         return r;
 563 }
 564
 565 /**
 566  * Fill the given pool if there aren't enough pages and the requested number of
 567  * pages is small.
 568  */
 569 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 570     int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 571 {
 572         vm_page_t p;
 573         int r;
 574         unsigned cpages = 0;
 575         /**
 576          * Only allow one pool fill operation at a time.
 577          * If pool doesn't have enough pages for the allocation new pages are
 578          * allocated from outside of pool.
 579          */
 580         if (pool->fill_lock)
 581                 return;
 582
 583         pool->fill_lock = true;
 584
 585         /* If allocation request is small and there are not enough
 586          * pages in a pool we fill the pool up first. */
 587         if (count < _manager->options.small
 588                 && count > pool->npages) {
 589                 struct pglist new_pages;
 590                 unsigned alloc_size = _manager->options.alloc_size;
 591
 592                 /**
 593                  * Can't change page caching if in irqsave context. We have to
 594                  * drop the pool->lock.
 595                  */
 596                 lockmgr(&pool->lock, LK_RELEASE);
 597
 598                 TAILQ_INIT(&new_pages);
 599                 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
 600                     ttm_flags, cstate, alloc_size);
 601                 lockmgr(&pool->lock, LK_EXCLUSIVE);
 602
 603                 if (!r) {
 604                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 605                         ++pool->nrefills;
 606                         pool->npages += alloc_size;
 607                 } else {
 608                         kprintf("[TTM] Failed to fill pool (%p)\n", pool);
 609                         /* If we have any pages left put them to the pool. */
 610                         TAILQ_FOREACH(p, &pool->list, pageq) {
 611                                 ++cpages;
 612                         }
 613                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 614                         pool->npages += cpages;
 615                 }
 616
 617         }
 618         pool->fill_lock = false;
 619 }
 620
 621 /**
 622  * Cut 'count' number of pages from the pool and put them on the return list.
 623  *
 624  * @return count of pages still required to fulfill the request.
 625  */
 626 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 627                                         struct pglist *pages,
 628                                         int ttm_flags,
 629                                         enum ttm_caching_state cstate,
 630                                         unsigned count)
 631 {
 632         vm_page_t p;
 633         unsigned i;
 634
 635         lockmgr(&pool->lock, LK_EXCLUSIVE);
 636         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
 637
 638         if (count >= pool->npages) {
 639                 /* take all pages from the pool */
 640                 TAILQ_CONCAT(pages, &pool->list, pageq);
 641                 count -= pool->npages;
 642                 pool->npages = 0;
 643                 goto out;
 644         }
 645         for (i = 0; i < count; i++) {
 646                 p = TAILQ_FIRST(&pool->list);
 647                 TAILQ_REMOVE(&pool->list, p, pageq);
 648                 TAILQ_INSERT_TAIL(pages, p, pageq);
 649         }
 650         pool->npages -= count;
 651         count = 0;
 652 out:
 653         lockmgr(&pool->lock, LK_RELEASE);
 654         return count;
 655 }
 656
 657 /* Put all pages in pages list to correct pool to wait for reuse */
 658 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
 659                           enum ttm_caching_state cstate)
 660 {
 661         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 662         unsigned i;
 663
 664         if (pool == NULL) {
 665                 /* No pool for this memory type so free the pages */
 666                 for (i = 0; i < npages; i++) {
 667                         if (pages[i]) {
 668                                 ttm_vm_page_free(pages[i]);
 669                                 pages[i] = NULL;
 670                         }
 671                 }
 672                 return;
 673         }
 674
 675         lockmgr(&pool->lock, LK_EXCLUSIVE);
 676         for (i = 0; i < npages; i++) {
 677                 if (pages[i]) {
 678                         TAILQ_INSERT_TAIL(&pool->list, pages[i], pageq);
 679                         pages[i] = NULL;
 680                         pool->npages++;
 681                 }
 682         }
 683         /* Check that we don't go over the pool limit */
 684         npages = 0;
 685         if (pool->npages > _manager->options.max_size) {
 686                 npages = pool->npages - _manager->options.max_size;
 687                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 688                  * to reduce calls to set_memory_wb */
 689                 if (npages < NUM_PAGES_TO_ALLOC)
 690                         npages = NUM_PAGES_TO_ALLOC;
 691         }
 692         lockmgr(&pool->lock, LK_RELEASE);
 693         if (npages)
 694                 ttm_page_pool_free(pool, npages);
 695 }
 696
 697 /*
 698  * On success pages list will hold count number of correctly
 699  * cached pages.
 700  */
 701 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
 702                          enum ttm_caching_state cstate)
 703 {
 704         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 705         struct pglist plist;
 706         vm_page_t p = NULL;
 707         int gfp_flags, aflags;
 708         unsigned count;
 709         int r;
 710
 711         aflags = VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED |
 712             ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ? VM_ALLOC_ZERO : 0);
 713
 714         /* No pool for cached pages */
 715         if (pool == NULL) {
 716                 for (r = 0; r < npages; ++r) {
 717                         p = vm_page_alloc_contig(0,
 718                             (flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 719                             VM_MAX_ADDRESS, PAGE_SIZE,
 720                             0, 1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 721                         if (!p) {
 722                                 kprintf("[TTM] Unable to allocate page\n");
 723                                 return -ENOMEM;
 724                         }
 725                         p->oflags &= ~VPO_UNMANAGED;
 726                         p->flags |= PG_FICTITIOUS;
 727                         pages[r] = p;
 728                 }
 729                 return 0;
 730         }
 731
 732         /* combine zero flag to pool flags */
 733         gfp_flags = flags | pool->ttm_page_alloc_flags;
 734
 735         /* First we take pages from the pool */
 736         TAILQ_INIT(&plist);
 737         npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
 738         count = 0;
 739         TAILQ_FOREACH(p, &plist, pageq) {
 740                 pages[count++] = p;
 741         }
 742
 743         /* clear the pages coming from the pool if requested */
 744         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 745                 TAILQ_FOREACH(p, &plist, pageq) {
 746                         pmap_zero_page(p);
 747                 }
 748         }
 749
 750         /* If pool didn't have enough pages allocate new one. */
 751         if (npages > 0) {
 752                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 753                  * multiple requests in parallel.
 754                  **/
 755                 TAILQ_INIT(&plist);
 756                 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
 757                     npages);
 758                 TAILQ_FOREACH(p, &plist, pageq) {
 759                         pages[count++] = p;
 760                 }
 761                 if (r) {
 762                         /* If there is any pages in the list put them back to
 763                          * the pool. */
 764                         kprintf("[TTM] Failed to allocate extra pages for large request\n");
 765                         ttm_put_pages(pages, count, flags, cstate);
 766                         return r;
 767                 }
 768         }
 769
 770         return 0;
 771 }
 772
 773 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 774                                       char *name)
 775 {
 776         lockinit(&pool->lock, "ttmpool", 0, LK_CANRECURSE);
 777         pool->fill_lock = false;
 778         TAILQ_INIT(&pool->list);
 779         pool->npages = pool->nfrees = 0;
 780         pool->ttm_page_alloc_flags = flags;
 781         pool->name = name;
 782 }
 783
 784 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 785 {
 786
 787         if (_manager != NULL)
 788                 kprintf("[TTM] manager != NULL\n");
 789         kprintf("[TTM] Initializing pool allocator\n");
 790
 791         _manager = kmalloc(sizeof(*_manager), M_TTM_POOLMGR, M_WAITOK | M_ZERO);
 792
 793         ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
 794         ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
 795         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 796             TTM_PAGE_FLAG_DMA32, "wc dma");
 797         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 798             TTM_PAGE_FLAG_DMA32, "uc dma");
 799
 800         _manager->options.max_size = max_pages;
 801         _manager->options.small = SMALL_ALLOCATION;
 802         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 803
 804         refcount_init(&_manager->kobj_ref, 1);
 805         ttm_pool_mm_shrink_init(_manager);
 806
 807         return 0;
 808 }
 809
 810 void ttm_page_alloc_fini(void)
 811 {
 812         int i;
 813
 814         kprintf("[TTM] Finalizing pool allocator\n");
 815         ttm_pool_mm_shrink_fini(_manager);
 816
 817         for (i = 0; i < NUM_POOLS; ++i)
 818                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 819
 820         if (refcount_release(&_manager->kobj_ref))
 821                 ttm_pool_kobj_release(_manager);
 822         _manager = NULL;
 823 }
 824
 825 int ttm_pool_populate(struct ttm_tt *ttm)
 826 {
 827         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 828         unsigned i;
 829         int ret;
 830
 831         if (ttm->state != tt_unpopulated)
 832                 return 0;
 833
 834         for (i = 0; i < ttm->num_pages; ++i) {
 835                 ret = ttm_get_pages(&ttm->pages[i], 1,
 836                                     ttm->page_flags,
 837                                     ttm->caching_state);
 838                 if (ret != 0) {
 839                         ttm_pool_unpopulate(ttm);
 840                         return -ENOMEM;
 841                 }
 842
 843                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 844                                                 false, false);
 845                 if (unlikely(ret != 0)) {
 846                         ttm_pool_unpopulate(ttm);
 847                         return -ENOMEM;
 848                 }
 849         }
 850
 851         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 852                 ret = ttm_tt_swapin(ttm);
 853                 if (unlikely(ret != 0)) {
 854                         ttm_pool_unpopulate(ttm);
 855                         return ret;
 856                 }
 857         }
 858
 859         ttm->state = tt_unbound;
 860         return 0;
 861 }
 862
 863 void ttm_pool_unpopulate(struct ttm_tt *ttm)
 864 {
 865         unsigned i;
 866
 867         for (i = 0; i < ttm->num_pages; ++i) {
 868                 if (ttm->pages[i]) {
 869                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 870                                                  ttm->pages[i]);
 871                         ttm_put_pages(&ttm->pages[i], 1,
 872                                       ttm->page_flags,
 873                                       ttm->caching_state);
 874                 }
 875         }
 876         ttm->state = tt_unpopulated;
 877 }
 878
 879 #if 0
 880 /* XXXKIB sysctl */
 881 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 882 {
 883         struct ttm_page_pool *p;
 884         unsigned i;
 885         char *h[] = {"pool", "refills", "pages freed", "size"};
 886         if (!_manager) {
 887                 seq_printf(m, "No pool allocator running.\n");
 888                 return 0;
 889         }
 890         seq_printf(m, "%6s %12s %13s %8s\n",
 891                         h[0], h[1], h[2], h[3]);
 892         for (i = 0; i < NUM_POOLS; ++i) {
 893                 p = &_manager->pools[i];
 894
 895                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 896                                 p->name, p->nrefills,
 897                                 p->nfrees, p->npages);
 898         }
 899         return 0;
 900 }
 901 #endif