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