sys/dev/drm2/ttm/ttm_page_alloc.c

   1 /*
   2  * Copyright (c) Red Hat Inc.
   3
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the
  12  * next paragraph) shall be included in all copies or substantial portions
  13  * of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors: Dave Airlie <airlied@redhat.com>
  24  *          Jerome Glisse <jglisse@redhat.com>
  25  *          Pauli Nieminen <suokkos@gmail.com>
  26  */
  27 /*
  28  * Copyright (c) 2013 The FreeBSD Foundation
  29  * All rights reserved.
  30  *
  31  * Portions of this software were developed by Konstantin Belousov
  32  * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
  33  */
  34
  35 /* simple list based uncached page pool
  36  * - Pool collects resently freed pages for reuse
  37  * - Use page->lru to keep a free list
  38  * - doesn't track currently in use pages
  39  */
  40
  41 #include <sys/cdefs.h>
  42 __FBSDID("$FreeBSD$");
  43
  44 #include <dev/drm2/drmP.h>
  45 #include <dev/drm2/ttm/ttm_bo_driver.h>
  46 #include <dev/drm2/ttm/ttm_page_alloc.h>
  47 #include <sys/eventhandler.h>
  48 #include <vm/vm_pageout.h>
  49
  50 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(vm_page_t))
  51 #define SMALL_ALLOCATION                16
  52 #define FREE_ALL_PAGES                  (~0U)
  53 /* times are in msecs */
  54 #define PAGE_FREE_INTERVAL              1000
  55
  56 /**
  57  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  58  *
  59  * @lock: Protects the shared pool from concurrnet access. Must be used with
  60  * irqsave/irqrestore variants because pool allocator maybe called from
  61  * delayed work.
  62  * @fill_lock: Prevent concurrent calls to fill.
  63  * @list: Pool of free uc/wc pages for fast reuse.
  64  * @gfp_flags: Flags to pass for alloc_page.
  65  * @npages: Number of pages in pool.
  66  */
  67 struct ttm_page_pool {
  68         struct mtx              lock;
  69         bool                    fill_lock;
  70         bool                    dma32;
  71         struct pglist           list;
  72         int                     ttm_page_alloc_flags;
  73         unsigned                npages;
  74         char                    *name;
  75         unsigned long           nfrees;
  76         unsigned long           nrefills;
  77 };
  78
  79 /**
  80  * Limits for the pool. They are handled without locks because only place where
  81  * they may change is in sysfs store. They won't have immediate effect anyway
  82  * so forcing serialization to access them is pointless.
  83  */
  84
  85 struct ttm_pool_opts {
  86         unsigned        alloc_size;
  87         unsigned        max_size;
  88         unsigned        small;
  89 };
  90
  91 #define NUM_POOLS 4
  92
  93 /**
  94  * struct ttm_pool_manager - Holds memory pools for fst allocation
  95  *
  96  * Manager is read only object for pool code so it doesn't need locking.
  97  *
  98  * @free_interval: minimum number of jiffies between freeing pages from pool.
  99  * @page_alloc_inited: reference counting for pool allocation.
 100  * @work: Work that is used to shrink the pool. Work is only run when there is
 101  * some pages to free.
 102  * @small_allocation: Limit in number of pages what is small allocation.
 103  *
 104  * @pools: All pool objects in use.
 105  **/
 106 struct ttm_pool_manager {
 107         unsigned int kobj_ref;
 108         eventhandler_tag lowmem_handler;
 109         struct ttm_pool_opts    options;
 110
 111         union {
 112                 struct ttm_page_pool    u_pools[NUM_POOLS];
 113                 struct _utag {
 114                         struct ttm_page_pool    u_wc_pool;
 115                         struct ttm_page_pool    u_uc_pool;
 116                         struct ttm_page_pool    u_wc_pool_dma32;
 117                         struct ttm_page_pool    u_uc_pool_dma32;
 118                 } _ut;
 119         } _u;
 120 };
 121
 122 #define pools _u.u_pools
 123 #define wc_pool _u._ut.u_wc_pool
 124 #define uc_pool _u._ut.u_uc_pool
 125 #define wc_pool_dma32 _u._ut.u_wc_pool_dma32
 126 #define uc_pool_dma32 _u._ut.u_uc_pool_dma32
 127
 128 MALLOC_DEFINE(M_TTM_POOLMGR, "ttm_poolmgr", "TTM Pool Manager");
 129
 130 static void
 131 ttm_vm_page_free(vm_page_t m)
 132 {
 133
 134         KASSERT(m->object == NULL, ("ttm page %p is owned", m));
 135         KASSERT(m->wire_count == 1, ("ttm lost wire %p", m));
 136         KASSERT((m->flags & PG_FICTITIOUS) != 0, ("ttm lost fictitious %p", m));
 137         KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("ttm got unmanaged %p", m));
 138         m->flags &= ~PG_FICTITIOUS;
 139         m->oflags |= VPO_UNMANAGED;
 140         vm_page_unwire(m, PQ_NONE);
 141         vm_page_free(m);
 142 }
 143
 144 static vm_memattr_t
 145 ttm_caching_state_to_vm(enum ttm_caching_state cstate)
 146 {
 147
 148         switch (cstate) {
 149         case tt_uncached:
 150                 return (VM_MEMATTR_UNCACHEABLE);
 151         case tt_wc:
 152                 return (VM_MEMATTR_WRITE_COMBINING);
 153         case tt_cached:
 154                 return (VM_MEMATTR_WRITE_BACK);
 155         }
 156         panic("caching state %d\n", cstate);
 157 }
 158
 159 static vm_page_t
 160 ttm_vm_page_alloc_dma32(int req, vm_memattr_t memattr)
 161 {
 162         vm_page_t p;
 163         int tries;
 164
 165         for (tries = 0; ; tries++) {
 166                 p = vm_page_alloc_contig(NULL, 0, req, 1, 0, 0xffffffff,
 167                     PAGE_SIZE, 0, memattr);
 168                 if (p != NULL || tries > 2)
 169                         return (p);
 170                 if (!vm_page_reclaim_contig(req, 1, 0, 0xffffffff,
 171                     PAGE_SIZE, 0))
 172                         vm_wait(NULL);
 173         }
 174 }
 175
 176 static vm_page_t
 177 ttm_vm_page_alloc_any(int req, vm_memattr_t memattr)
 178 {
 179         vm_page_t p;
 180
 181         while (1) {
 182                 p = vm_page_alloc(NULL, 0, req);
 183                 if (p != NULL)
 184                         break;
 185                 vm_wait(NULL);
 186         }
 187         pmap_page_set_memattr(p, memattr);
 188         return (p);
 189 }
 190
 191 static vm_page_t
 192 ttm_vm_page_alloc(int flags, enum ttm_caching_state cstate)
 193 {
 194         vm_page_t p;
 195         vm_memattr_t memattr;
 196         int req;
 197
 198         memattr = ttm_caching_state_to_vm(cstate);
 199         req = VM_ALLOC_NORMAL | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ;
 200         if ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0)
 201                 req |= VM_ALLOC_ZERO;
 202
 203         if ((flags & TTM_PAGE_FLAG_DMA32) != 0)
 204                 p = ttm_vm_page_alloc_dma32(req, memattr);
 205         else
 206                 p = ttm_vm_page_alloc_any(req, memattr);
 207
 208         if (p != NULL) {
 209                 p->oflags &= ~VPO_UNMANAGED;
 210                 p->flags |= PG_FICTITIOUS;
 211         }
 212         return (p);
 213 }
 214
 215 static void ttm_pool_kobj_release(struct ttm_pool_manager *m)
 216 {
 217
 218         free(m, M_TTM_POOLMGR);
 219 }
 220
 221 #if 0
 222 /* XXXKIB sysctl */
 223 static ssize_t ttm_pool_store(struct ttm_pool_manager *m,
 224                 struct attribute *attr, const char *buffer, size_t size)
 225 {
 226         int chars;
 227         unsigned val;
 228         chars = sscanf(buffer, "%u", &val);
 229         if (chars == 0)
 230                 return size;
 231
 232         /* Convert kb to number of pages */
 233         val = val / (PAGE_SIZE >> 10);
 234
 235         if (attr == &ttm_page_pool_max)
 236                 m->options.max_size = val;
 237         else if (attr == &ttm_page_pool_small)
 238                 m->options.small = val;
 239         else if (attr == &ttm_page_pool_alloc_size) {
 240                 if (val > NUM_PAGES_TO_ALLOC*8) {
 241                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 242                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 243                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 244                         return size;
 245                 } else if (val > NUM_PAGES_TO_ALLOC) {
 246                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 247                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 248                 }
 249                 m->options.alloc_size = val;
 250         }
 251
 252         return size;
 253 }
 254
 255 static ssize_t ttm_pool_show(struct ttm_pool_manager *m,
 256                 struct attribute *attr, char *buffer)
 257 {
 258         unsigned val = 0;
 259
 260         if (attr == &ttm_page_pool_max)
 261                 val = m->options.max_size;
 262         else if (attr == &ttm_page_pool_small)
 263                 val = m->options.small;
 264         else if (attr == &ttm_page_pool_alloc_size)
 265                 val = m->options.alloc_size;
 266
 267         val = val * (PAGE_SIZE >> 10);
 268
 269         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 270 }
 271 #endif
 272
 273 static struct ttm_pool_manager *_manager;
 274
 275 static int set_pages_array_wb(vm_page_t *pages, int addrinarray)
 276 {
 277 #ifdef TTM_HAS_AGP
 278         int i;
 279
 280         for (i = 0; i < addrinarray; i++)
 281                 pmap_page_set_memattr(pages[i], VM_MEMATTR_WRITE_BACK);
 282 #endif
 283         return 0;
 284 }
 285
 286 static int set_pages_array_wc(vm_page_t *pages, int addrinarray)
 287 {
 288 #ifdef TTM_HAS_AGP
 289         int i;
 290
 291         for (i = 0; i < addrinarray; i++)
 292                 pmap_page_set_memattr(pages[i], VM_MEMATTR_WRITE_COMBINING);
 293 #endif
 294         return 0;
 295 }
 296
 297 static int set_pages_array_uc(vm_page_t *pages, int addrinarray)
 298 {
 299 #ifdef TTM_HAS_AGP
 300         int i;
 301
 302         for (i = 0; i < addrinarray; i++)
 303                 pmap_page_set_memattr(pages[i], VM_MEMATTR_UNCACHEABLE);
 304 #endif
 305         return 0;
 306 }
 307
 308 /**
 309  * Select the right pool or requested caching state and ttm flags. */
 310 static struct ttm_page_pool *ttm_get_pool(int flags,
 311                 enum ttm_caching_state cstate)
 312 {
 313         int pool_index;
 314
 315         if (cstate == tt_cached)
 316                 return NULL;
 317
 318         if (cstate == tt_wc)
 319                 pool_index = 0x0;
 320         else
 321                 pool_index = 0x1;
 322
 323         if (flags & TTM_PAGE_FLAG_DMA32)
 324                 pool_index |= 0x2;
 325
 326         return &_manager->pools[pool_index];
 327 }
 328
 329 /* set memory back to wb and free the pages. */
 330 static void ttm_pages_put(vm_page_t *pages, unsigned npages)
 331 {
 332         unsigned i;
 333
 334         /* Our VM handles vm memattr automatically on the page free. */
 335         if (set_pages_array_wb(pages, npages))
 336                 printf("[TTM] Failed to set %d pages to wb!\n", npages);
 337         for (i = 0; i < npages; ++i)
 338                 ttm_vm_page_free(pages[i]);
 339 }
 340
 341 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 342                 unsigned freed_pages)
 343 {
 344         pool->npages -= freed_pages;
 345         pool->nfrees += freed_pages;
 346 }
 347
 348 /**
 349  * Free pages from pool.
 350  *
 351  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 352  * number of pages in one go.
 353  *
 354  * @pool: to free the pages from
 355  * @free_all: If set to true will free all pages in pool
 356  **/
 357 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 358 {
 359         vm_page_t p, p1;
 360         vm_page_t *pages_to_free;
 361         unsigned freed_pages = 0,
 362                  npages_to_free = nr_free;
 363         unsigned i;
 364
 365         if (NUM_PAGES_TO_ALLOC < nr_free)
 366                 npages_to_free = NUM_PAGES_TO_ALLOC;
 367
 368         pages_to_free = malloc(npages_to_free * sizeof(vm_page_t),
 369             M_TEMP, M_WAITOK | M_ZERO);
 370
 371 restart:
 372         mtx_lock(&pool->lock);
 373
 374         TAILQ_FOREACH_REVERSE_SAFE(p, &pool->list, pglist, plinks.q, p1) {
 375                 if (freed_pages >= npages_to_free)
 376                         break;
 377
 378                 pages_to_free[freed_pages++] = p;
 379                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 380                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 381                         /* remove range of pages from the pool */
 382                         for (i = 0; i < freed_pages; i++)
 383                                 TAILQ_REMOVE(&pool->list, pages_to_free[i], plinks.q);
 384
 385                         ttm_pool_update_free_locked(pool, freed_pages);
 386                         /**
 387                          * Because changing page caching is costly
 388                          * we unlock the pool to prevent stalling.
 389                          */
 390                         mtx_unlock(&pool->lock);
 391
 392                         ttm_pages_put(pages_to_free, freed_pages);
 393                         if (likely(nr_free != FREE_ALL_PAGES))
 394                                 nr_free -= freed_pages;
 395
 396                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 397                                 npages_to_free = nr_free;
 398                         else
 399                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 400
 401                         freed_pages = 0;
 402
 403                         /* free all so restart the processing */
 404                         if (nr_free)
 405                                 goto restart;
 406
 407                         /* Not allowed to fall through or break because
 408                          * following context is inside spinlock while we are
 409                          * outside here.
 410                          */
 411                         goto out;
 412
 413                 }
 414         }
 415
 416         /* remove range of pages from the pool */
 417         if (freed_pages) {
 418                 for (i = 0; i < freed_pages; i++)
 419                         TAILQ_REMOVE(&pool->list, pages_to_free[i], plinks.q);
 420
 421                 ttm_pool_update_free_locked(pool, freed_pages);
 422                 nr_free -= freed_pages;
 423         }
 424
 425         mtx_unlock(&pool->lock);
 426
 427         if (freed_pages)
 428                 ttm_pages_put(pages_to_free, freed_pages);
 429 out:
 430         free(pages_to_free, M_TEMP);
 431         return nr_free;
 432 }
 433
 434 /* Get good estimation how many pages are free in pools */
 435 static int ttm_pool_get_num_unused_pages(void)
 436 {
 437         unsigned i;
 438         int total = 0;
 439         for (i = 0; i < NUM_POOLS; ++i)
 440                 total += _manager->pools[i].npages;
 441
 442         return total;
 443 }
 444
 445 /**
 446  * Callback for mm to request pool to reduce number of page held.
 447  */
 448 static int ttm_pool_mm_shrink(void *arg)
 449 {
 450         static unsigned int start_pool = 0;
 451         unsigned i;
 452         unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
 453         struct ttm_page_pool *pool;
 454         int shrink_pages = 100; /* XXXKIB */
 455
 456         pool_offset = pool_offset % NUM_POOLS;
 457         /* select start pool in round robin fashion */
 458         for (i = 0; i < NUM_POOLS; ++i) {
 459                 unsigned nr_free = shrink_pages;
 460                 if (shrink_pages == 0)
 461                         break;
 462                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 463                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 464         }
 465         /* return estimated number of unused pages in pool */
 466         return ttm_pool_get_num_unused_pages();
 467 }
 468
 469 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 470 {
 471
 472         manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
 473             ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
 474 }
 475
 476 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 477 {
 478
 479         EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
 480 }
 481
 482 static int ttm_set_pages_caching(vm_page_t *pages,
 483                 enum ttm_caching_state cstate, unsigned cpages)
 484 {
 485         int r = 0;
 486         /* Set page caching */
 487         switch (cstate) {
 488         case tt_uncached:
 489                 r = set_pages_array_uc(pages, cpages);
 490                 if (r)
 491                         printf("[TTM] Failed to set %d pages to uc!\n", cpages);
 492                 break;
 493         case tt_wc:
 494                 r = set_pages_array_wc(pages, cpages);
 495                 if (r)
 496                         printf("[TTM] Failed to set %d pages to wc!\n", cpages);
 497                 break;
 498         default:
 499                 break;
 500         }
 501         return r;
 502 }
 503
 504 /**
 505  * Free pages the pages that failed to change the caching state. If there is
 506  * any pages that have changed their caching state already put them to the
 507  * pool.
 508  */
 509 static void ttm_handle_caching_state_failure(struct pglist *pages,
 510                 int ttm_flags, enum ttm_caching_state cstate,
 511                 vm_page_t *failed_pages, unsigned cpages)
 512 {
 513         unsigned i;
 514         /* Failed pages have to be freed */
 515         for (i = 0; i < cpages; ++i) {
 516                 TAILQ_REMOVE(pages, failed_pages[i], plinks.q);
 517                 ttm_vm_page_free(failed_pages[i]);
 518         }
 519 }
 520
 521 /**
 522  * Allocate new pages with correct caching.
 523  *
 524  * This function is reentrant if caller updates count depending on number of
 525  * pages returned in pages array.
 526  */
 527 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
 528                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 529 {
 530         vm_page_t *caching_array;
 531         vm_page_t p;
 532         int r = 0;
 533         unsigned i, cpages;
 534         unsigned max_cpages = min(count,
 535                         (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
 536
 537         /* allocate array for page caching change */
 538         caching_array = malloc(max_cpages * sizeof(vm_page_t), M_TEMP,
 539             M_WAITOK | M_ZERO);
 540
 541         for (i = 0, cpages = 0; i < count; ++i) {
 542                 p = ttm_vm_page_alloc(ttm_alloc_flags, cstate);
 543                 if (!p) {
 544                         printf("[TTM] Unable to get page %u\n", i);
 545
 546                         /* store already allocated pages in the pool after
 547                          * setting the caching state */
 548                         if (cpages) {
 549                                 r = ttm_set_pages_caching(caching_array,
 550                                                           cstate, cpages);
 551                                 if (r)
 552                                         ttm_handle_caching_state_failure(pages,
 553                                                 ttm_flags, cstate,
 554                                                 caching_array, cpages);
 555                         }
 556                         r = -ENOMEM;
 557                         goto out;
 558                 }
 559
 560 #ifdef CONFIG_HIGHMEM /* KIB: nop */
 561                 /* gfp flags of highmem page should never be dma32 so we
 562                  * we should be fine in such case
 563                  */
 564                 if (!PageHighMem(p))
 565 #endif
 566                 {
 567                         caching_array[cpages++] = p;
 568                         if (cpages == max_cpages) {
 569
 570                                 r = ttm_set_pages_caching(caching_array,
 571                                                 cstate, cpages);
 572                                 if (r) {
 573                                         ttm_handle_caching_state_failure(pages,
 574                                                 ttm_flags, cstate,
 575                                                 caching_array, cpages);
 576                                         goto out;
 577                                 }
 578                                 cpages = 0;
 579                         }
 580                 }
 581
 582                 TAILQ_INSERT_HEAD(pages, p, plinks.q);
 583         }
 584
 585         if (cpages) {
 586                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 587                 if (r)
 588                         ttm_handle_caching_state_failure(pages,
 589                                         ttm_flags, cstate,
 590                                         caching_array, cpages);
 591         }
 592 out:
 593         free(caching_array, M_TEMP);
 594
 595         return r;
 596 }
 597
 598 /**
 599  * Fill the given pool if there aren't enough pages and the requested number of
 600  * pages is small.
 601  */
 602 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 603     int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 604 {
 605         vm_page_t p;
 606         int r;
 607         unsigned cpages = 0;
 608         /**
 609          * Only allow one pool fill operation at a time.
 610          * If pool doesn't have enough pages for the allocation new pages are
 611          * allocated from outside of pool.
 612          */
 613         if (pool->fill_lock)
 614                 return;
 615
 616         pool->fill_lock = true;
 617
 618         /* If allocation request is small and there are not enough
 619          * pages in a pool we fill the pool up first. */
 620         if (count < _manager->options.small
 621                 && count > pool->npages) {
 622                 struct pglist new_pages;
 623                 unsigned alloc_size = _manager->options.alloc_size;
 624
 625                 /**
 626                  * Can't change page caching if in irqsave context. We have to
 627                  * drop the pool->lock.
 628                  */
 629                 mtx_unlock(&pool->lock);
 630
 631                 TAILQ_INIT(&new_pages);
 632                 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
 633                     ttm_flags, cstate, alloc_size);
 634                 mtx_lock(&pool->lock);
 635
 636                 if (!r) {
 637                         TAILQ_CONCAT(&pool->list, &new_pages, plinks.q);
 638                         ++pool->nrefills;
 639                         pool->npages += alloc_size;
 640                 } else {
 641                         printf("[TTM] Failed to fill pool (%p)\n", pool);
 642                         /* If we have any pages left put them to the pool. */
 643                         TAILQ_FOREACH(p, &pool->list, plinks.q) {
 644                                 ++cpages;
 645                         }
 646                         TAILQ_CONCAT(&pool->list, &new_pages, plinks.q);
 647                         pool->npages += cpages;
 648                 }
 649
 650         }
 651         pool->fill_lock = false;
 652 }
 653
 654 /**
 655  * Cut 'count' number of pages from the pool and put them on the return list.
 656  *
 657  * @return count of pages still required to fulfill the request.
 658  */
 659 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 660                                         struct pglist *pages,
 661                                         int ttm_flags,
 662                                         enum ttm_caching_state cstate,
 663                                         unsigned count)
 664 {
 665         vm_page_t p;
 666         unsigned i;
 667
 668         mtx_lock(&pool->lock);
 669         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
 670
 671         if (count >= pool->npages) {
 672                 /* take all pages from the pool */
 673                 TAILQ_CONCAT(pages, &pool->list, plinks.q);
 674                 count -= pool->npages;
 675                 pool->npages = 0;
 676                 goto out;
 677         }
 678         for (i = 0; i < count; i++) {
 679                 p = TAILQ_FIRST(&pool->list);
 680                 TAILQ_REMOVE(&pool->list, p, plinks.q);
 681                 TAILQ_INSERT_TAIL(pages, p, plinks.q);
 682         }
 683         pool->npages -= count;
 684         count = 0;
 685 out:
 686         mtx_unlock(&pool->lock);
 687         return count;
 688 }
 689
 690 /* Put all pages in pages list to correct pool to wait for reuse */
 691 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
 692                           enum ttm_caching_state cstate)
 693 {
 694         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 695         unsigned i;
 696
 697         if (pool == NULL) {
 698                 /* No pool for this memory type so free the pages */
 699                 for (i = 0; i < npages; i++) {
 700                         if (pages[i]) {
 701                                 ttm_vm_page_free(pages[i]);
 702                                 pages[i] = NULL;
 703                         }
 704                 }
 705                 return;
 706         }
 707
 708         mtx_lock(&pool->lock);
 709         for (i = 0; i < npages; i++) {
 710                 if (pages[i]) {
 711                         TAILQ_INSERT_TAIL(&pool->list, pages[i], plinks.q);
 712                         pages[i] = NULL;
 713                         pool->npages++;
 714                 }
 715         }
 716         /* Check that we don't go over the pool limit */
 717         npages = 0;
 718         if (pool->npages > _manager->options.max_size) {
 719                 npages = pool->npages - _manager->options.max_size;
 720                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 721                  * to reduce calls to set_memory_wb */
 722                 if (npages < NUM_PAGES_TO_ALLOC)
 723                         npages = NUM_PAGES_TO_ALLOC;
 724         }
 725         mtx_unlock(&pool->lock);
 726         if (npages)
 727                 ttm_page_pool_free(pool, npages);
 728 }
 729
 730 /*
 731  * On success pages list will hold count number of correctly
 732  * cached pages.
 733  */
 734 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
 735                          enum ttm_caching_state cstate)
 736 {
 737         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 738         struct pglist plist;
 739         vm_page_t p = NULL;
 740         int gfp_flags;
 741         unsigned count;
 742         int r;
 743
 744         /* No pool for cached pages */
 745         if (pool == NULL) {
 746                 for (r = 0; r < npages; ++r) {
 747                         p = ttm_vm_page_alloc(flags, cstate);
 748                         if (!p) {
 749                                 printf("[TTM] Unable to allocate page\n");
 750                                 return -ENOMEM;
 751                         }
 752                         pages[r] = p;
 753                 }
 754                 return 0;
 755         }
 756
 757         /* combine zero flag to pool flags */
 758         gfp_flags = flags | pool->ttm_page_alloc_flags;
 759
 760         /* First we take pages from the pool */
 761         TAILQ_INIT(&plist);
 762         npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
 763         count = 0;
 764         TAILQ_FOREACH(p, &plist, plinks.q) {
 765                 pages[count++] = p;
 766         }
 767
 768         /* clear the pages coming from the pool if requested */
 769         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 770                 TAILQ_FOREACH(p, &plist, plinks.q) {
 771                         pmap_zero_page(p);
 772                 }
 773         }
 774
 775         /* If pool didn't have enough pages allocate new one. */
 776         if (npages > 0) {
 777                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 778                  * multiple requests in parallel.
 779                  **/
 780                 TAILQ_INIT(&plist);
 781                 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
 782                     npages);
 783                 TAILQ_FOREACH(p, &plist, plinks.q) {
 784                         pages[count++] = p;
 785                 }
 786                 if (r) {
 787                         /* If there is any pages in the list put them back to
 788                          * the pool. */
 789                         printf("[TTM] Failed to allocate extra pages for large request\n");
 790                         ttm_put_pages(pages, count, flags, cstate);
 791                         return r;
 792                 }
 793         }
 794
 795         return 0;
 796 }
 797
 798 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 799                                       char *name)
 800 {
 801         mtx_init(&pool->lock, "ttmpool", NULL, MTX_DEF);
 802         pool->fill_lock = false;
 803         TAILQ_INIT(&pool->list);
 804         pool->npages = pool->nfrees = 0;
 805         pool->ttm_page_alloc_flags = flags;
 806         pool->name = name;
 807 }
 808
 809 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 810 {
 811
 812         if (_manager != NULL)
 813                 printf("[TTM] manager != NULL\n");
 814         printf("[TTM] Initializing pool allocator\n");
 815
 816         _manager = malloc(sizeof(*_manager), M_TTM_POOLMGR, M_WAITOK | M_ZERO);
 817
 818         ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
 819         ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
 820         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 821             TTM_PAGE_FLAG_DMA32, "wc dma");
 822         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 823             TTM_PAGE_FLAG_DMA32, "uc dma");
 824
 825         _manager->options.max_size = max_pages;
 826         _manager->options.small = SMALL_ALLOCATION;
 827         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 828
 829         refcount_init(&_manager->kobj_ref, 1);
 830         ttm_pool_mm_shrink_init(_manager);
 831
 832         return 0;
 833 }
 834
 835 void ttm_page_alloc_fini(void)
 836 {
 837         int i;
 838
 839         printf("[TTM] Finalizing pool allocator\n");
 840         ttm_pool_mm_shrink_fini(_manager);
 841
 842         for (i = 0; i < NUM_POOLS; ++i)
 843                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 844
 845         if (refcount_release(&_manager->kobj_ref))
 846                 ttm_pool_kobj_release(_manager);
 847         _manager = NULL;
 848 }
 849
 850 int ttm_pool_populate(struct ttm_tt *ttm)
 851 {
 852         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 853         unsigned i;
 854         int ret;
 855
 856         if (ttm->state != tt_unpopulated)
 857                 return 0;
 858
 859         for (i = 0; i < ttm->num_pages; ++i) {
 860                 ret = ttm_get_pages(&ttm->pages[i], 1,
 861                                     ttm->page_flags,
 862                                     ttm->caching_state);
 863                 if (ret != 0) {
 864                         ttm_pool_unpopulate(ttm);
 865                         return -ENOMEM;
 866                 }
 867
 868                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 869                                                 false, false);
 870                 if (unlikely(ret != 0)) {
 871                         ttm_pool_unpopulate(ttm);
 872                         return -ENOMEM;
 873                 }
 874         }
 875
 876         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 877                 ret = ttm_tt_swapin(ttm);
 878                 if (unlikely(ret != 0)) {
 879                         ttm_pool_unpopulate(ttm);
 880                         return ret;
 881                 }
 882         }
 883
 884         ttm->state = tt_unbound;
 885         return 0;
 886 }
 887
 888 void ttm_pool_unpopulate(struct ttm_tt *ttm)
 889 {
 890         unsigned i;
 891
 892         for (i = 0; i < ttm->num_pages; ++i) {
 893                 if (ttm->pages[i]) {
 894                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 895                                                  ttm->pages[i]);
 896                         ttm_put_pages(&ttm->pages[i], 1,
 897                                       ttm->page_flags,
 898                                       ttm->caching_state);
 899                 }
 900         }
 901         ttm->state = tt_unpopulated;
 902 }
 903
 904 #if 0
 905 /* XXXKIB sysctl */
 906 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 907 {
 908         struct ttm_page_pool *p;
 909         unsigned i;
 910         char *h[] = {"pool", "refills", "pages freed", "size"};
 911         if (!_manager) {
 912                 seq_printf(m, "No pool allocator running.\n");
 913                 return 0;
 914         }
 915         seq_printf(m, "%6s %12s %13s %8s\n",
 916                         h[0], h[1], h[2], h[3]);
 917         for (i = 0; i < NUM_POOLS; ++i) {
 918                 p = &_manager->pools[i];
 919
 920                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 921                                 p->name, p->nrefills,
 922                                 p->nfrees, p->npages);
 923         }
 924         return 0;
 925 }
 926 #endif