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 <dev/drm/drmP.h>
  46 #include <dev/drm/ttm/ttm_bo_driver.h>
  47 #include <dev/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_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         unsigned i;
 325
 326         if (NUM_PAGES_TO_ALLOC < nr_free)
 327                 npages_to_free = NUM_PAGES_TO_ALLOC;
 328
 329         pages_to_free = kmalloc(npages_to_free * sizeof(vm_page_t),
 330             M_TEMP, M_WAITOK | M_ZERO);
 331
 332 restart:
 333         lockmgr(&pool->lock, LK_EXCLUSIVE);
 334
 335         TAILQ_FOREACH_REVERSE_MUTABLE(p, &pool->list, pglist, pageq, p1) {
 336                 if (freed_pages >= npages_to_free)
 337                         break;
 338
 339                 pages_to_free[freed_pages++] = p;
 340                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 341                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 342                         /* remove range of pages from the pool */
 343                         for (i = 0; i < freed_pages; i++)
 344                                 TAILQ_REMOVE(&pool->list, pages_to_free[i], pageq);
 345
 346                         ttm_pool_update_free_locked(pool, freed_pages);
 347                         /**
 348                          * Because changing page caching is costly
 349                          * we unlock the pool to prevent stalling.
 350                          */
 351                         lockmgr(&pool->lock, LK_RELEASE);
 352
 353                         ttm_pages_put(pages_to_free, freed_pages);
 354                         if (likely(nr_free != FREE_ALL_PAGES))
 355                                 nr_free -= freed_pages;
 356
 357                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 358                                 npages_to_free = nr_free;
 359                         else
 360                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 361
 362                         freed_pages = 0;
 363
 364                         /* free all so restart the processing */
 365                         if (nr_free)
 366                                 goto restart;
 367
 368                         /* Not allowed to fall through or break because
 369                          * following context is inside spinlock while we are
 370                          * outside here.
 371                          */
 372                         goto out;
 373
 374                 }
 375         }
 376
 377         /* remove range of pages from the pool */
 378         if (freed_pages) {
 379                 for (i = 0; i < freed_pages; i++)
 380                         TAILQ_REMOVE(&pool->list, pages_to_free[i], pageq);
 381
 382                 ttm_pool_update_free_locked(pool, freed_pages);
 383                 nr_free -= freed_pages;
 384         }
 385
 386         lockmgr(&pool->lock, LK_RELEASE);
 387
 388         if (freed_pages)
 389                 ttm_pages_put(pages_to_free, freed_pages);
 390 out:
 391         drm_free(pages_to_free, M_TEMP);
 392         return nr_free;
 393 }
 394
 395 /* Get good estimation how many pages are free in pools */
 396 static int ttm_pool_get_num_unused_pages(void)
 397 {
 398         unsigned i;
 399         int total = 0;
 400         for (i = 0; i < NUM_POOLS; ++i)
 401                 total += _manager->pools[i].npages;
 402
 403         return total;
 404 }
 405
 406 /**
 407  * Callback for mm to request pool to reduce number of page held.
 408  */
 409 static int ttm_pool_mm_shrink(void *arg)
 410 {
 411         static unsigned int start_pool = 0;
 412         unsigned i;
 413         unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
 414         struct ttm_page_pool *pool;
 415         int shrink_pages = 100; /* XXXKIB */
 416
 417         pool_offset = pool_offset % NUM_POOLS;
 418         /* select start pool in round robin fashion */
 419         for (i = 0; i < NUM_POOLS; ++i) {
 420                 unsigned nr_free = shrink_pages;
 421                 if (shrink_pages == 0)
 422                         break;
 423                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 424                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 425         }
 426         /* return estimated number of unused pages in pool */
 427         return ttm_pool_get_num_unused_pages();
 428 }
 429
 430 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 431 {
 432
 433         manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
 434             ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
 435 }
 436
 437 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 438 {
 439
 440         EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
 441 }
 442
 443 static int ttm_set_pages_caching(vm_page_t *pages,
 444                 enum ttm_caching_state cstate, unsigned cpages)
 445 {
 446         int r = 0;
 447         /* Set page caching */
 448         switch (cstate) {
 449         case tt_uncached:
 450                 r = set_pages_array_uc(pages, cpages);
 451                 if (r)
 452                         kprintf("[TTM] Failed to set %d pages to uc!\n", cpages);
 453                 break;
 454         case tt_wc:
 455                 r = set_pages_array_wc(pages, cpages);
 456                 if (r)
 457                         kprintf("[TTM] Failed to set %d pages to wc!\n", cpages);
 458                 break;
 459         default:
 460                 break;
 461         }
 462         return r;
 463 }
 464
 465 /**
 466  * Free pages the pages that failed to change the caching state. If there is
 467  * any pages that have changed their caching state already put them to the
 468  * pool.
 469  */
 470 static void ttm_handle_caching_state_failure(struct pglist *pages,
 471                 int ttm_flags, enum ttm_caching_state cstate,
 472                 vm_page_t *failed_pages, unsigned cpages)
 473 {
 474         unsigned i;
 475         /* Failed pages have to be freed */
 476         for (i = 0; i < cpages; ++i) {
 477                 TAILQ_REMOVE(pages, failed_pages[i], pageq);
 478                 ttm_vm_page_free(failed_pages[i]);
 479         }
 480 }
 481
 482 /**
 483  * Allocate new pages with correct caching.
 484  *
 485  * This function is reentrant if caller updates count depending on number of
 486  * pages returned in pages array.
 487  */
 488 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
 489                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 490 {
 491         vm_page_t *caching_array;
 492         vm_page_t p;
 493         int r = 0;
 494         unsigned i, cpages, aflags;
 495         unsigned max_cpages = min(count,
 496                         (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
 497
 498         aflags = VM_ALLOC_NORMAL |
 499             ((ttm_alloc_flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ?
 500             VM_ALLOC_ZERO : 0);
 501
 502         /* allocate array for page caching change */
 503         caching_array = kmalloc(max_cpages * sizeof(vm_page_t), M_TEMP,
 504             M_WAITOK | M_ZERO);
 505
 506         for (i = 0, cpages = 0; i < count; ++i) {
 507                 p = vm_page_alloc_contig(0,
 508                     (ttm_alloc_flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 509                     VM_MAX_ADDRESS, PAGE_SIZE, 0,
 510                     1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 511                 if (!p) {
 512                         kprintf("[TTM] Unable to get page %u\n", i);
 513
 514                         /* store already allocated pages in the pool after
 515                          * setting the caching state */
 516                         if (cpages) {
 517                                 r = ttm_set_pages_caching(caching_array,
 518                                                           cstate, cpages);
 519                                 if (r)
 520                                         ttm_handle_caching_state_failure(pages,
 521                                                 ttm_flags, cstate,
 522                                                 caching_array, cpages);
 523                         }
 524                         r = -ENOMEM;
 525                         goto out;
 526                 }
 527 #if 0
 528                 p->oflags &= ~VPO_UNMANAGED;
 529 #endif
 530                 p->flags |= PG_FICTITIOUS;
 531
 532 #ifdef CONFIG_HIGHMEM /* KIB: nop */
 533                 /* gfp flags of highmem page should never be dma32 so we
 534                  * we should be fine in such case
 535                  */
 536                 if (!PageHighMem(p))
 537 #endif
 538                 {
 539                         caching_array[cpages++] = p;
 540                         if (cpages == max_cpages) {
 541
 542                                 r = ttm_set_pages_caching(caching_array,
 543                                                 cstate, cpages);
 544                                 if (r) {
 545                                         ttm_handle_caching_state_failure(pages,
 546                                                 ttm_flags, cstate,
 547                                                 caching_array, cpages);
 548                                         goto out;
 549                                 }
 550                                 cpages = 0;
 551                         }
 552                 }
 553
 554                 TAILQ_INSERT_HEAD(pages, p, pageq);
 555         }
 556
 557         if (cpages) {
 558                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 559                 if (r)
 560                         ttm_handle_caching_state_failure(pages,
 561                                         ttm_flags, cstate,
 562                                         caching_array, cpages);
 563         }
 564 out:
 565         drm_free(caching_array, M_TEMP);
 566
 567         return r;
 568 }
 569
 570 /**
 571  * Fill the given pool if there aren't enough pages and the requested number of
 572  * pages is small.
 573  */
 574 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 575     int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 576 {
 577         vm_page_t p;
 578         int r;
 579         unsigned cpages = 0;
 580         /**
 581          * Only allow one pool fill operation at a time.
 582          * If pool doesn't have enough pages for the allocation new pages are
 583          * allocated from outside of pool.
 584          */
 585         if (pool->fill_lock)
 586                 return;
 587
 588         pool->fill_lock = true;
 589
 590         /* If allocation request is small and there are not enough
 591          * pages in a pool we fill the pool up first. */
 592         if (count < _manager->options.small
 593                 && count > pool->npages) {
 594                 struct pglist new_pages;
 595                 unsigned alloc_size = _manager->options.alloc_size;
 596
 597                 /**
 598                  * Can't change page caching if in irqsave context. We have to
 599                  * drop the pool->lock.
 600                  */
 601                 lockmgr(&pool->lock, LK_RELEASE);
 602
 603                 TAILQ_INIT(&new_pages);
 604                 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
 605                     ttm_flags, cstate, alloc_size);
 606                 lockmgr(&pool->lock, LK_EXCLUSIVE);
 607
 608                 if (!r) {
 609                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 610                         ++pool->nrefills;
 611                         pool->npages += alloc_size;
 612                 } else {
 613                         kprintf("[TTM] Failed to fill pool (%p)\n", pool);
 614                         /* If we have any pages left put them to the pool. */
 615                         TAILQ_FOREACH(p, &pool->list, pageq) {
 616                                 ++cpages;
 617                         }
 618                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 619                         pool->npages += cpages;
 620                 }
 621
 622         }
 623         pool->fill_lock = false;
 624 }
 625
 626 /**
 627  * Cut 'count' number of pages from the pool and put them on the return list.
 628  *
 629  * @return count of pages still required to fulfill the request.
 630  */
 631 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 632                                         struct pglist *pages,
 633                                         int ttm_flags,
 634                                         enum ttm_caching_state cstate,
 635                                         unsigned count)
 636 {
 637         vm_page_t p;
 638         unsigned i;
 639
 640         lockmgr(&pool->lock, LK_EXCLUSIVE);
 641         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
 642
 643         if (count >= pool->npages) {
 644                 /* take all pages from the pool */
 645                 TAILQ_CONCAT(pages, &pool->list, pageq);
 646                 count -= pool->npages;
 647                 pool->npages = 0;
 648                 goto out;
 649         }
 650         for (i = 0; i < count; i++) {
 651                 p = TAILQ_FIRST(&pool->list);
 652                 TAILQ_REMOVE(&pool->list, p, pageq);
 653                 TAILQ_INSERT_TAIL(pages, p, pageq);
 654         }
 655         pool->npages -= count;
 656         count = 0;
 657 out:
 658         lockmgr(&pool->lock, LK_RELEASE);
 659         return count;
 660 }
 661
 662 /* Put all pages in pages list to correct pool to wait for reuse */
 663 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
 664                           enum ttm_caching_state cstate)
 665 {
 666         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 667         unsigned i;
 668
 669         if (pool == NULL) {
 670                 /* No pool for this memory type so free the pages */
 671                 for (i = 0; i < npages; i++) {
 672                         if (pages[i]) {
 673                                 ttm_vm_page_free(pages[i]);
 674                                 pages[i] = NULL;
 675                         }
 676                 }
 677                 return;
 678         }
 679
 680         lockmgr(&pool->lock, LK_EXCLUSIVE);
 681         for (i = 0; i < npages; i++) {
 682                 if (pages[i]) {
 683                         TAILQ_INSERT_TAIL(&pool->list, pages[i], pageq);
 684                         pages[i] = NULL;
 685                         pool->npages++;
 686                 }
 687         }
 688         /* Check that we don't go over the pool limit */
 689         npages = 0;
 690         if (pool->npages > _manager->options.max_size) {
 691                 npages = pool->npages - _manager->options.max_size;
 692                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 693                  * to reduce calls to set_memory_wb */
 694                 if (npages < NUM_PAGES_TO_ALLOC)
 695                         npages = NUM_PAGES_TO_ALLOC;
 696         }
 697         lockmgr(&pool->lock, LK_RELEASE);
 698         if (npages)
 699                 ttm_page_pool_free(pool, npages);
 700 }
 701
 702 /*
 703  * On success pages list will hold count number of correctly
 704  * cached pages.
 705  */
 706 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
 707                          enum ttm_caching_state cstate)
 708 {
 709         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 710         struct pglist plist;
 711         vm_page_t p = NULL;
 712         int gfp_flags, aflags;
 713         unsigned count;
 714         int r;
 715
 716         aflags = VM_ALLOC_NORMAL |
 717             ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ? VM_ALLOC_ZERO : 0);
 718
 719         /* No pool for cached pages */
 720         if (pool == NULL) {
 721                 for (r = 0; r < npages; ++r) {
 722                         p = vm_page_alloc_contig(0,
 723                             (flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 724                             VM_MAX_ADDRESS, PAGE_SIZE,
 725                             0, 1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 726                         if (!p) {
 727                                 kprintf("[TTM] Unable to allocate page\n");
 728                                 return -ENOMEM;
 729                         }
 730 #if 0
 731                         p->oflags &= ~VPO_UNMANAGED;
 732 #endif
 733                         p->flags |= PG_FICTITIOUS;
 734                         pages[r] = p;
 735                 }
 736                 return 0;
 737         }
 738
 739         /* combine zero flag to pool flags */
 740         gfp_flags = flags | pool->ttm_page_alloc_flags;
 741
 742         /* First we take pages from the pool */
 743         TAILQ_INIT(&plist);
 744         npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
 745         count = 0;
 746         TAILQ_FOREACH(p, &plist, pageq) {
 747                 pages[count++] = p;
 748         }
 749
 750         /* clear the pages coming from the pool if requested */
 751         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 752                 TAILQ_FOREACH(p, &plist, pageq) {
 753                         pmap_zero_page(VM_PAGE_TO_PHYS(p));
 754                 }
 755         }
 756
 757         /* If pool didn't have enough pages allocate new one. */
 758         if (npages > 0) {
 759                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 760                  * multiple requests in parallel.
 761                  **/
 762                 TAILQ_INIT(&plist);
 763                 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
 764                     npages);
 765                 TAILQ_FOREACH(p, &plist, pageq) {
 766                         pages[count++] = p;
 767                 }
 768                 if (r) {
 769                         /* If there is any pages in the list put them back to
 770                          * the pool. */
 771                         kprintf("[TTM] Failed to allocate extra pages for large request\n");
 772                         ttm_put_pages(pages, count, flags, cstate);
 773                         return r;
 774                 }
 775         }
 776
 777         return 0;
 778 }
 779
 780 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 781                                       char *name)
 782 {
 783         lockinit(&pool->lock, "ttmpool", 0, LK_CANRECURSE);
 784         pool->fill_lock = false;
 785         TAILQ_INIT(&pool->list);
 786         pool->npages = pool->nfrees = 0;
 787         pool->ttm_page_alloc_flags = flags;
 788         pool->name = name;
 789 }
 790
 791 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 792 {
 793
 794         if (_manager != NULL)
 795                 kprintf("[TTM] manager != NULL\n");
 796         kprintf("[TTM] Initializing pool allocator\n");
 797
 798         _manager = kmalloc(sizeof(*_manager), M_TTM_POOLMGR, M_WAITOK | M_ZERO);
 799
 800         ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
 801         ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
 802         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 803             TTM_PAGE_FLAG_DMA32, "wc dma");
 804         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 805             TTM_PAGE_FLAG_DMA32, "uc dma");
 806
 807         _manager->options.max_size = max_pages;
 808         _manager->options.small = SMALL_ALLOCATION;
 809         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 810
 811         refcount_init(&_manager->kobj_ref, 1);
 812         ttm_pool_mm_shrink_init(_manager);
 813
 814         return 0;
 815 }
 816
 817 void ttm_page_alloc_fini(void)
 818 {
 819         int i;
 820
 821         kprintf("[TTM] Finalizing pool allocator\n");
 822         ttm_pool_mm_shrink_fini(_manager);
 823
 824         for (i = 0; i < NUM_POOLS; ++i)
 825                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 826
 827         if (refcount_release(&_manager->kobj_ref))
 828                 ttm_pool_kobj_release(_manager);
 829         _manager = NULL;
 830 }
 831
 832 int ttm_pool_populate(struct ttm_tt *ttm)
 833 {
 834         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 835         unsigned i;
 836         int ret;
 837
 838         if (ttm->state != tt_unpopulated)
 839                 return 0;
 840
 841         for (i = 0; i < ttm->num_pages; ++i) {
 842                 ret = ttm_get_pages(&ttm->pages[i], 1,
 843                                     ttm->page_flags,
 844                                     ttm->caching_state);
 845                 if (ret != 0) {
 846                         ttm_pool_unpopulate(ttm);
 847                         return -ENOMEM;
 848                 }
 849
 850                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 851                                                 false, false);
 852                 if (unlikely(ret != 0)) {
 853                         ttm_pool_unpopulate(ttm);
 854                         return -ENOMEM;
 855                 }
 856         }
 857
 858         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 859                 ret = ttm_tt_swapin(ttm);
 860                 if (unlikely(ret != 0)) {
 861                         ttm_pool_unpopulate(ttm);
 862                         return ret;
 863                 }
 864         }
 865
 866         ttm->state = tt_unbound;
 867         return 0;
 868 }
 869
 870 void ttm_pool_unpopulate(struct ttm_tt *ttm)
 871 {
 872         unsigned i;
 873
 874         for (i = 0; i < ttm->num_pages; ++i) {
 875                 if (ttm->pages[i]) {
 876                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 877                                                  ttm->pages[i]);
 878                         ttm_put_pages(&ttm->pages[i], 1,
 879                                       ttm->page_flags,
 880                                       ttm->caching_state);
 881                 }
 882         }
 883         ttm->state = tt_unpopulated;
 884 }
 885
 886 #if 0
 887 /* XXXKIB sysctl */
 888 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 889 {
 890         struct ttm_page_pool *p;
 891         unsigned i;
 892         char *h[] = {"pool", "refills", "pages freed", "size"};
 893         if (!_manager) {
 894                 seq_printf(m, "No pool allocator running.\n");
 895                 return 0;
 896         }
 897         seq_printf(m, "%6s %12s %13s %8s\n",
 898                         h[0], h[1], h[2], h[3]);
 899         for (i = 0; i < NUM_POOLS; ++i) {
 900                 p = &_manager->pools[i];
 901
 902                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 903                                 p->name, p->nrefills,
 904                                 p->nfrees, p->npages);
 905         }
 906         return 0;
 907 }
 908 #endif