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 VM_ALLOC_DMA32  VM_ALLOC_RESERVED1
  54
  55 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(vm_page_t))
  56 #define SMALL_ALLOCATION                16
  57 #define FREE_ALL_PAGES                  (~0U)
  58 /* times are in msecs */
  59 #define PAGE_FREE_INTERVAL              1000
  60
  61 /**
  62  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  63  *
  64  * @lock: Protects the shared pool from concurrnet access. Must be used with
  65  * irqsave/irqrestore variants because pool allocator maybe called from
  66  * delayed work.
  67  * @fill_lock: Prevent concurrent calls to fill.
  68  * @list: Pool of free uc/wc pages for fast reuse.
  69  * @gfp_flags: Flags to pass for alloc_page.
  70  * @npages: Number of pages in pool.
  71  */
  72 struct ttm_page_pool {
  73         struct lock             lock;
  74         bool                    fill_lock;
  75         bool                    dma32;
  76         struct pglist           list;
  77         int                     ttm_page_alloc_flags;
  78         unsigned                npages;
  79         char                    *name;
  80         unsigned long           nfrees;
  81         unsigned long           nrefills;
  82 };
  83
  84 /**
  85  * Limits for the pool. They are handled without locks because only place where
  86  * they may change is in sysfs store. They won't have immediate effect anyway
  87  * so forcing serialization to access them is pointless.
  88  */
  89
  90 struct ttm_pool_opts {
  91         unsigned        alloc_size;
  92         unsigned        max_size;
  93         unsigned        small;
  94 };
  95
  96 #define NUM_POOLS 4
  97
  98 /**
  99  * struct ttm_pool_manager - Holds memory pools for fst allocation
 100  *
 101  * Manager is read only object for pool code so it doesn't need locking.
 102  *
 103  * @free_interval: minimum number of jiffies between freeing pages from pool.
 104  * @page_alloc_inited: reference counting for pool allocation.
 105  * @work: Work that is used to shrink the pool. Work is only run when there is
 106  * some pages to free.
 107  * @small_allocation: Limit in number of pages what is small allocation.
 108  *
 109  * @pools: All pool objects in use.
 110  **/
 111 struct ttm_pool_manager {
 112         unsigned int kobj_ref;
 113         eventhandler_tag lowmem_handler;
 114         struct ttm_pool_opts    options;
 115
 116         union {
 117                 struct ttm_page_pool    u_pools[NUM_POOLS];
 118                 struct _utag {
 119                         struct ttm_page_pool    u_wc_pool;
 120                         struct ttm_page_pool    u_uc_pool;
 121                         struct ttm_page_pool    u_wc_pool_dma32;
 122                         struct ttm_page_pool    u_uc_pool_dma32;
 123                 } _ut;
 124         } _u;
 125 };
 126
 127 #define pools _u.u_pools
 128 #define wc_pool _u._ut.u_wc_pool
 129 #define uc_pool _u._ut.u_uc_pool
 130 #define wc_pool_dma32 _u._ut.u_wc_pool_dma32
 131 #define uc_pool_dma32 _u._ut.u_uc_pool_dma32
 132
 133 MALLOC_DEFINE(M_TTM_POOLMGR, "ttm_poolmgr", "TTM Pool Manager");
 134
 135 static void
 136 ttm_vm_page_free(vm_page_t m)
 137 {
 138
 139         KASSERT(m->object == NULL, ("ttm page %p is owned", m));
 140         KASSERT(m->wire_count == 1, ("ttm lost wire %p", m));
 141         KASSERT((m->flags & PG_FICTITIOUS) != 0, ("ttm lost fictitious %p", m));
 142 #if 0
 143         KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("ttm got unmanaged %p", m));
 144         m->oflags |= VPO_UNMANAGED;
 145 #endif
 146         m->flags &= ~PG_FICTITIOUS;
 147         vm_page_unwire(m, 0);
 148         vm_page_free(m);
 149 }
 150
 151 static vm_memattr_t
 152 ttm_caching_state_to_vm(enum ttm_caching_state cstate)
 153 {
 154
 155         switch (cstate) {
 156         case tt_uncached:
 157                 return (VM_MEMATTR_UNCACHEABLE);
 158         case tt_wc:
 159                 return (VM_MEMATTR_WRITE_COMBINING);
 160         case tt_cached:
 161                 return (VM_MEMATTR_WRITE_BACK);
 162         }
 163         panic("caching state %d\n", cstate);
 164 }
 165
 166 static void ttm_pool_kobj_release(struct ttm_pool_manager *m)
 167 {
 168
 169         drm_free(m, M_TTM_POOLMGR);
 170 }
 171
 172 #if 0
 173 /* XXXKIB sysctl */
 174 static ssize_t ttm_pool_store(struct ttm_pool_manager *m,
 175                 struct attribute *attr, const char *buffer, size_t size)
 176 {
 177         int chars;
 178         unsigned val;
 179         chars = sscanf(buffer, "%u", &val);
 180         if (chars == 0)
 181                 return size;
 182
 183         /* Convert kb to number of pages */
 184         val = val / (PAGE_SIZE >> 10);
 185
 186         if (attr == &ttm_page_pool_max)
 187                 m->options.max_size = val;
 188         else if (attr == &ttm_page_pool_small)
 189                 m->options.small = val;
 190         else if (attr == &ttm_page_pool_alloc_size) {
 191                 if (val > NUM_PAGES_TO_ALLOC*8) {
 192                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 193                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 194                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 195                         return size;
 196                 } else if (val > NUM_PAGES_TO_ALLOC) {
 197                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 198                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 199                 }
 200                 m->options.alloc_size = val;
 201         }
 202
 203         return size;
 204 }
 205
 206 static ssize_t ttm_pool_show(struct ttm_pool_manager *m,
 207                 struct attribute *attr, char *buffer)
 208 {
 209         unsigned val = 0;
 210
 211         if (attr == &ttm_page_pool_max)
 212                 val = m->options.max_size;
 213         else if (attr == &ttm_page_pool_small)
 214                 val = m->options.small;
 215         else if (attr == &ttm_page_pool_alloc_size)
 216                 val = m->options.alloc_size;
 217
 218         val = val * (PAGE_SIZE >> 10);
 219
 220         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 221 }
 222 #endif
 223
 224 static struct ttm_pool_manager *_manager;
 225
 226 static int set_pages_array_wb(vm_page_t *pages, int addrinarray)
 227 {
 228         vm_page_t m;
 229         int i;
 230
 231         for (i = 0; i < addrinarray; i++) {
 232                 m = pages[i];
 233 #ifdef TTM_HAS_AGP
 234                 unmap_page_from_agp(m);
 235 #endif
 236                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_BACK);
 237         }
 238         return 0;
 239 }
 240
 241 static int set_pages_array_wc(vm_page_t *pages, int addrinarray)
 242 {
 243         vm_page_t m;
 244         int i;
 245
 246         for (i = 0; i < addrinarray; i++) {
 247                 m = pages[i];
 248 #ifdef TTM_HAS_AGP
 249                 map_page_into_agp(pages[i]);
 250 #endif
 251                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_COMBINING);
 252         }
 253         return 0;
 254 }
 255
 256 static int set_pages_array_uc(vm_page_t *pages, int addrinarray)
 257 {
 258         vm_page_t m;
 259         int i;
 260
 261         for (i = 0; i < addrinarray; i++) {
 262                 m = pages[i];
 263 #ifdef TTM_HAS_AGP
 264                 map_page_into_agp(pages[i]);
 265 #endif
 266                 pmap_page_set_memattr(m, VM_MEMATTR_UNCACHEABLE);
 267         }
 268         return 0;
 269 }
 270
 271 /**
 272  * Select the right pool or requested caching state and ttm flags. */
 273 static struct ttm_page_pool *ttm_get_pool(int flags,
 274                 enum ttm_caching_state cstate)
 275 {
 276         int pool_index;
 277
 278         if (cstate == tt_cached)
 279                 return NULL;
 280
 281         if (cstate == tt_wc)
 282                 pool_index = 0x0;
 283         else
 284                 pool_index = 0x1;
 285
 286         if (flags & TTM_PAGE_FLAG_DMA32)
 287                 pool_index |= 0x2;
 288
 289         return &_manager->pools[pool_index];
 290 }
 291
 292 /* set memory back to wb and free the pages. */
 293 static void ttm_pages_put(vm_page_t *pages, unsigned npages)
 294 {
 295         unsigned i;
 296
 297         /* Our VM handles vm memattr automatically on the page free. */
 298         if (set_pages_array_wb(pages, npages))
 299                 kprintf("[TTM] Failed to set %d pages to wb!\n", npages);
 300         for (i = 0; i < npages; ++i)
 301                 ttm_vm_page_free(pages[i]);
 302 }
 303
 304 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 305                 unsigned freed_pages)
 306 {
 307         pool->npages -= freed_pages;
 308         pool->nfrees += freed_pages;
 309 }
 310
 311 /**
 312  * Free pages from pool.
 313  *
 314  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 315  * number of pages in one go.
 316  *
 317  * @pool: to free the pages from
 318  * @free_all: If set to true will free all pages in pool
 319  **/
 320 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 321 {
 322         vm_page_t p, p1;
 323         vm_page_t *pages_to_free;
 324         unsigned freed_pages = 0,
 325                  npages_to_free = nr_free;
 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                         TAILQ_REMOVE(&pool->list, p, 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                 TAILQ_REMOVE(&pool->list, p, pageq);
 380
 381                 ttm_pool_update_free_locked(pool, freed_pages);
 382                 nr_free -= freed_pages;
 383         }
 384
 385         lockmgr(&pool->lock, LK_RELEASE);
 386
 387         if (freed_pages)
 388                 ttm_pages_put(pages_to_free, freed_pages);
 389 out:
 390         drm_free(pages_to_free, M_TEMP);
 391         return nr_free;
 392 }
 393
 394 /* Get good estimation how many pages are free in pools */
 395 static int ttm_pool_get_num_unused_pages(void)
 396 {
 397         unsigned i;
 398         int total = 0;
 399         for (i = 0; i < NUM_POOLS; ++i)
 400                 total += _manager->pools[i].npages;
 401
 402         return total;
 403 }
 404
 405 /**
 406  * Callback for mm to request pool to reduce number of page held.
 407  */
 408 static int ttm_pool_mm_shrink(void *arg)
 409 {
 410         static unsigned int start_pool = 0;
 411         unsigned i;
 412         unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
 413         struct ttm_page_pool *pool;
 414         int shrink_pages = 100; /* XXXKIB */
 415
 416         pool_offset = pool_offset % NUM_POOLS;
 417         /* select start pool in round robin fashion */
 418         for (i = 0; i < NUM_POOLS; ++i) {
 419                 unsigned nr_free = shrink_pages;
 420                 if (shrink_pages == 0)
 421                         break;
 422                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 423                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 424         }
 425         /* return estimated number of unused pages in pool */
 426         return ttm_pool_get_num_unused_pages();
 427 }
 428
 429 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 430 {
 431
 432         manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
 433             ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
 434 }
 435
 436 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 437 {
 438
 439         EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
 440 }
 441
 442 static int ttm_set_pages_caching(vm_page_t *pages,
 443                 enum ttm_caching_state cstate, unsigned cpages)
 444 {
 445         int r = 0;
 446         /* Set page caching */
 447         switch (cstate) {
 448         case tt_uncached:
 449                 r = set_pages_array_uc(pages, cpages);
 450                 if (r)
 451                         kprintf("[TTM] Failed to set %d pages to uc!\n", cpages);
 452                 break;
 453         case tt_wc:
 454                 r = set_pages_array_wc(pages, cpages);
 455                 if (r)
 456                         kprintf("[TTM] Failed to set %d pages to wc!\n", cpages);
 457                 break;
 458         default:
 459                 break;
 460         }
 461         return r;
 462 }
 463
 464 /**
 465  * Free pages the pages that failed to change the caching state. If there is
 466  * any pages that have changed their caching state already put them to the
 467  * pool.
 468  */
 469 static void ttm_handle_caching_state_failure(struct pglist *pages,
 470                 int ttm_flags, enum ttm_caching_state cstate,
 471                 vm_page_t *failed_pages, unsigned cpages)
 472 {
 473         unsigned i;
 474         /* Failed pages have to be freed */
 475         for (i = 0; i < cpages; ++i) {
 476                 TAILQ_REMOVE(pages, failed_pages[i], pageq);
 477                 ttm_vm_page_free(failed_pages[i]);
 478         }
 479 }
 480
 481 /**
 482  * Allocate new pages with correct caching.
 483  *
 484  * This function is reentrant if caller updates count depending on number of
 485  * pages returned in pages array.
 486  */
 487 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
 488                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 489 {
 490         vm_page_t *caching_array;
 491         vm_page_t p;
 492         int r = 0;
 493         unsigned i, cpages, aflags;
 494         unsigned max_cpages = min(count,
 495                         (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
 496
 497         aflags = VM_ALLOC_NORMAL |
 498             ((ttm_alloc_flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ?
 499             VM_ALLOC_ZERO : 0);
 500
 501         /* allocate array for page caching change */
 502         caching_array = kmalloc(max_cpages * sizeof(vm_page_t), M_TEMP,
 503             M_WAITOK | M_ZERO);
 504
 505         for (i = 0, cpages = 0; i < count; ++i) {
 506                 p = vm_page_alloc_contig(0,
 507                     (ttm_alloc_flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 508                     VM_MAX_ADDRESS, PAGE_SIZE, 0,
 509                     1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 510                 if (!p) {
 511                         kprintf("[TTM] Unable to get page %u\n", i);
 512
 513                         /* store already allocated pages in the pool after
 514                          * setting the caching state */
 515                         if (cpages) {
 516                                 r = ttm_set_pages_caching(caching_array,
 517                                                           cstate, cpages);
 518                                 if (r)
 519                                         ttm_handle_caching_state_failure(pages,
 520                                                 ttm_flags, cstate,
 521                                                 caching_array, cpages);
 522                         }
 523                         r = -ENOMEM;
 524                         goto out;
 525                 }
 526 #if 0
 527                 p->oflags &= ~VPO_UNMANAGED;
 528 #endif
 529                 p->flags |= PG_FICTITIOUS;
 530
 531 #ifdef CONFIG_HIGHMEM /* KIB: nop */
 532                 /* gfp flags of highmem page should never be dma32 so we
 533                  * we should be fine in such case
 534                  */
 535                 if (!PageHighMem(p))
 536 #endif
 537                 {
 538                         caching_array[cpages++] = p;
 539                         if (cpages == max_cpages) {
 540
 541                                 r = ttm_set_pages_caching(caching_array,
 542                                                 cstate, cpages);
 543                                 if (r) {
 544                                         ttm_handle_caching_state_failure(pages,
 545                                                 ttm_flags, cstate,
 546                                                 caching_array, cpages);
 547                                         goto out;
 548                                 }
 549                                 cpages = 0;
 550                         }
 551                 }
 552
 553                 TAILQ_INSERT_HEAD(pages, p, pageq);
 554         }
 555
 556         if (cpages) {
 557                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 558                 if (r)
 559                         ttm_handle_caching_state_failure(pages,
 560                                         ttm_flags, cstate,
 561                                         caching_array, cpages);
 562         }
 563 out:
 564         drm_free(caching_array, M_TEMP);
 565
 566         return r;
 567 }
 568
 569 /**
 570  * Fill the given pool if there aren't enough pages and the requested number of
 571  * pages is small.
 572  */
 573 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 574     int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 575 {
 576         vm_page_t p;
 577         int r;
 578         unsigned cpages = 0;
 579         /**
 580          * Only allow one pool fill operation at a time.
 581          * If pool doesn't have enough pages for the allocation new pages are
 582          * allocated from outside of pool.
 583          */
 584         if (pool->fill_lock)
 585                 return;
 586
 587         pool->fill_lock = true;
 588
 589         /* If allocation request is small and there are not enough
 590          * pages in a pool we fill the pool up first. */
 591         if (count < _manager->options.small
 592                 && count > pool->npages) {
 593                 struct pglist new_pages;
 594                 unsigned alloc_size = _manager->options.alloc_size;
 595
 596                 /**
 597                  * Can't change page caching if in irqsave context. We have to
 598                  * drop the pool->lock.
 599                  */
 600                 lockmgr(&pool->lock, LK_RELEASE);
 601
 602                 TAILQ_INIT(&new_pages);
 603                 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
 604                     ttm_flags, cstate, alloc_size);
 605                 lockmgr(&pool->lock, LK_EXCLUSIVE);
 606
 607                 if (!r) {
 608                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 609                         ++pool->nrefills;
 610                         pool->npages += alloc_size;
 611                 } else {
 612                         kprintf("[TTM] Failed to fill pool (%p)\n", pool);
 613                         /* If we have any pages left put them to the pool. */
 614                         TAILQ_FOREACH(p, &pool->list, pageq) {
 615                                 ++cpages;
 616                         }
 617                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 618                         pool->npages += cpages;
 619                 }
 620
 621         }
 622         pool->fill_lock = false;
 623 }
 624
 625 /**
 626  * Cut 'count' number of pages from the pool and put them on the return list.
 627  *
 628  * @return count of pages still required to fulfill the request.
 629  */
 630 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 631                                         struct pglist *pages,
 632                                         int ttm_flags,
 633                                         enum ttm_caching_state cstate,
 634                                         unsigned count)
 635 {
 636         vm_page_t p;
 637         unsigned i;
 638
 639         lockmgr(&pool->lock, LK_EXCLUSIVE);
 640         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
 641
 642         if (count >= pool->npages) {
 643                 /* take all pages from the pool */
 644                 TAILQ_CONCAT(pages, &pool->list, pageq);
 645                 count -= pool->npages;
 646                 pool->npages = 0;
 647                 goto out;
 648         }
 649         for (i = 0; i < count; i++) {
 650                 p = TAILQ_FIRST(&pool->list);
 651                 TAILQ_REMOVE(&pool->list, p, pageq);
 652                 TAILQ_INSERT_TAIL(pages, p, pageq);
 653         }
 654         pool->npages -= count;
 655         count = 0;
 656 out:
 657         lockmgr(&pool->lock, LK_RELEASE);
 658         return count;
 659 }
 660
 661 /* Put all pages in pages list to correct pool to wait for reuse */
 662 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
 663                           enum ttm_caching_state cstate)
 664 {
 665         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 666         unsigned i;
 667
 668         if (pool == NULL) {
 669                 /* No pool for this memory type so free the pages */
 670                 for (i = 0; i < npages; i++) {
 671                         if (pages[i]) {
 672                                 ttm_vm_page_free(pages[i]);
 673                                 pages[i] = NULL;
 674                         }
 675                 }
 676                 return;
 677         }
 678
 679         lockmgr(&pool->lock, LK_EXCLUSIVE);
 680         for (i = 0; i < npages; i++) {
 681                 if (pages[i]) {
 682                         TAILQ_INSERT_TAIL(&pool->list, pages[i], pageq);
 683                         pages[i] = NULL;
 684                         pool->npages++;
 685                 }
 686         }
 687         /* Check that we don't go over the pool limit */
 688         npages = 0;
 689         if (pool->npages > _manager->options.max_size) {
 690                 npages = pool->npages - _manager->options.max_size;
 691                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 692                  * to reduce calls to set_memory_wb */
 693                 if (npages < NUM_PAGES_TO_ALLOC)
 694                         npages = NUM_PAGES_TO_ALLOC;
 695         }
 696         lockmgr(&pool->lock, LK_RELEASE);
 697         if (npages)
 698                 ttm_page_pool_free(pool, npages);
 699 }
 700
 701 /*
 702  * On success pages list will hold count number of correctly
 703  * cached pages.
 704  */
 705 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
 706                          enum ttm_caching_state cstate)
 707 {
 708         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 709         struct pglist plist;
 710         vm_page_t p = NULL;
 711         int gfp_flags, aflags;
 712         unsigned count;
 713         int r;
 714
 715         aflags = VM_ALLOC_NORMAL |
 716             ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ? VM_ALLOC_ZERO : 0);
 717
 718         /* No pool for cached pages */
 719         if (pool == NULL) {
 720                 for (r = 0; r < npages; ++r) {
 721                         p = vm_page_alloc_contig(0,
 722                             (flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 723                             VM_MAX_ADDRESS, PAGE_SIZE,
 724                             0, 1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 725                         if (!p) {
 726                                 kprintf("[TTM] Unable to allocate page\n");
 727                                 return -ENOMEM;
 728                         }
 729 #if 0
 730                         p->oflags &= ~VPO_UNMANAGED;
 731 #endif
 732                         p->flags |= PG_FICTITIOUS;
 733                         pages[r] = p;
 734                 }
 735                 return 0;
 736         }
 737
 738         /* combine zero flag to pool flags */
 739         gfp_flags = flags | pool->ttm_page_alloc_flags;
 740
 741         /* First we take pages from the pool */
 742         TAILQ_INIT(&plist);
 743         npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
 744         count = 0;
 745         TAILQ_FOREACH(p, &plist, pageq) {
 746                 pages[count++] = p;
 747         }
 748
 749         /* clear the pages coming from the pool if requested */
 750         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 751                 TAILQ_FOREACH(p, &plist, pageq) {
 752                         pmap_zero_page(VM_PAGE_TO_PHYS(p));
 753                 }
 754         }
 755
 756         /* If pool didn't have enough pages allocate new one. */
 757         if (npages > 0) {
 758                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 759                  * multiple requests in parallel.
 760                  **/
 761                 TAILQ_INIT(&plist);
 762                 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
 763                     npages);
 764                 TAILQ_FOREACH(p, &plist, pageq) {
 765                         pages[count++] = p;
 766                 }
 767                 if (r) {
 768                         /* If there is any pages in the list put them back to
 769                          * the pool. */
 770                         kprintf("[TTM] Failed to allocate extra pages for large request\n");
 771                         ttm_put_pages(pages, count, flags, cstate);
 772                         return r;
 773                 }
 774         }
 775
 776         return 0;
 777 }
 778
 779 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 780                                       char *name)
 781 {
 782         lockinit(&pool->lock, "ttmpool", 0, LK_CANRECURSE);
 783         pool->fill_lock = false;
 784         TAILQ_INIT(&pool->list);
 785         pool->npages = pool->nfrees = 0;
 786         pool->ttm_page_alloc_flags = flags;
 787         pool->name = name;
 788 }
 789
 790 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 791 {
 792
 793         if (_manager != NULL)
 794                 kprintf("[TTM] manager != NULL\n");
 795         kprintf("[TTM] Initializing pool allocator\n");
 796
 797         _manager = kmalloc(sizeof(*_manager), M_TTM_POOLMGR, M_WAITOK | M_ZERO);
 798
 799         ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
 800         ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
 801         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 802             TTM_PAGE_FLAG_DMA32, "wc dma");
 803         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 804             TTM_PAGE_FLAG_DMA32, "uc dma");
 805
 806         _manager->options.max_size = max_pages;
 807         _manager->options.small = SMALL_ALLOCATION;
 808         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 809
 810         refcount_init(&_manager->kobj_ref, 1);
 811         ttm_pool_mm_shrink_init(_manager);
 812
 813         return 0;
 814 }
 815
 816 void ttm_page_alloc_fini(void)
 817 {
 818         int i;
 819
 820         kprintf("[TTM] Finalizing pool allocator\n");
 821         ttm_pool_mm_shrink_fini(_manager);
 822
 823         for (i = 0; i < NUM_POOLS; ++i)
 824                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 825
 826         if (refcount_release(&_manager->kobj_ref))
 827                 ttm_pool_kobj_release(_manager);
 828         _manager = NULL;
 829 }
 830
 831 int ttm_pool_populate(struct ttm_tt *ttm)
 832 {
 833         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 834         unsigned i;
 835         int ret;
 836
 837         if (ttm->state != tt_unpopulated)
 838                 return 0;
 839
 840         for (i = 0; i < ttm->num_pages; ++i) {
 841                 ret = ttm_get_pages(&ttm->pages[i], 1,
 842                                     ttm->page_flags,
 843                                     ttm->caching_state);
 844                 if (ret != 0) {
 845                         ttm_pool_unpopulate(ttm);
 846                         return -ENOMEM;
 847                 }
 848
 849                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 850                                                 false, false);
 851                 if (unlikely(ret != 0)) {
 852                         ttm_pool_unpopulate(ttm);
 853                         return -ENOMEM;
 854                 }
 855         }
 856
 857         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 858                 ret = ttm_tt_swapin(ttm);
 859                 if (unlikely(ret != 0)) {
 860                         ttm_pool_unpopulate(ttm);
 861                         return ret;
 862                 }
 863         }
 864
 865         ttm->state = tt_unbound;
 866         return 0;
 867 }
 868
 869 void ttm_pool_unpopulate(struct ttm_tt *ttm)
 870 {
 871         unsigned i;
 872
 873         for (i = 0; i < ttm->num_pages; ++i) {
 874                 if (ttm->pages[i]) {
 875                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 876                                                  ttm->pages[i]);
 877                         ttm_put_pages(&ttm->pages[i], 1,
 878                                       ttm->page_flags,
 879                                       ttm->caching_state);
 880                 }
 881         }
 882         ttm->state = tt_unpopulated;
 883 }
 884
 885 #if 0
 886 /* XXXKIB sysctl */
 887 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 888 {
 889         struct ttm_page_pool *p;
 890         unsigned i;
 891         char *h[] = {"pool", "refills", "pages freed", "size"};
 892         if (!_manager) {
 893                 seq_printf(m, "No pool allocator running.\n");
 894                 return 0;
 895         }
 896         seq_printf(m, "%6s %12s %13s %8s\n",
 897                         h[0], h[1], h[2], h[3]);
 898         for (i = 0; i < NUM_POOLS; ++i) {
 899                 p = &_manager->pools[i];
 900
 901                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 902                                 p->name, p->nrefills,
 903                                 p->nfrees, p->npages);
 904         }
 905         return 0;
 906 }
 907 #endif