sys/dev/drm/ttm/ttm_page_alloc.c

   1 /*
   2  * Copyright (c) Red Hat Inc.
   3
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the
  12  * next paragraph) shall be included in all copies or substantial portions
  13  * of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors: Dave Airlie <airlied@redhat.com>
  24  *          Jerome Glisse <jglisse@redhat.com>
  25  *          Pauli Nieminen <suokkos@gmail.com>
  26  */
  27 /*
  28  * Copyright (c) 2013 The FreeBSD Foundation
  29  * All rights reserved.
  30  *
  31  * Portions of this software were developed by Konstantin Belousov
  32  * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
  33  *
  34  * $FreeBSD: head/sys/dev/drm2/ttm/ttm_page_alloc.c 247849 2013-03-05 16:15:34Z kib $
  35  */
  36
  37 /* simple list based uncached page pool
  38  * - Pool collects resently freed pages for reuse
  39  * - Use page->lru to keep a free list
  40  * - doesn't track currently in use pages
  41  */
  42
  43 #include <sys/eventhandler.h>
  44
  45 #include <drm/drmP.h>
  46 #include <drm/ttm/ttm_bo_driver.h>
  47 #include <drm/ttm/ttm_page_alloc.h>
  48
  49 #ifdef TTM_HAS_AGP
  50 #include <asm/agp.h>
  51 #endif
  52
  53 #define NUM_PAGES_TO_ALLOC              (PAGE_SIZE/sizeof(vm_page_t))
  54 #define SMALL_ALLOCATION                16
  55 #define FREE_ALL_PAGES                  (~0U)
  56 /* times are in msecs */
  57 #define PAGE_FREE_INTERVAL              1000
  58
  59 /**
  60  * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
  61  *
  62  * @lock: Protects the shared pool from concurrnet access. Must be used with
  63  * irqsave/irqrestore variants because pool allocator maybe called from
  64  * delayed work.
  65  * @fill_lock: Prevent concurrent calls to fill.
  66  * @list: Pool of free uc/wc pages for fast reuse.
  67  * @gfp_flags: Flags to pass for alloc_page.
  68  * @npages: Number of pages in pool.
  69  */
  70 struct ttm_page_pool {
  71         struct lock             lock;
  72         bool                    fill_lock;
  73         bool                    dma32;
  74         struct pglist           list;
  75         int                     ttm_page_alloc_flags;
  76         unsigned                npages;
  77         char                    *name;
  78         unsigned long           nfrees;
  79         unsigned long           nrefills;
  80 };
  81
  82 /**
  83  * Limits for the pool. They are handled without locks because only place where
  84  * they may change is in sysfs store. They won't have immediate effect anyway
  85  * so forcing serialization to access them is pointless.
  86  */
  87
  88 struct ttm_pool_opts {
  89         unsigned        alloc_size;
  90         unsigned        max_size;
  91         unsigned        small;
  92 };
  93
  94 #define NUM_POOLS 4
  95
  96 /**
  97  * struct ttm_pool_manager - Holds memory pools for fst allocation
  98  *
  99  * Manager is read only object for pool code so it doesn't need locking.
 100  *
 101  * @free_interval: minimum number of jiffies between freeing pages from pool.
 102  * @page_alloc_inited: reference counting for pool allocation.
 103  * @work: Work that is used to shrink the pool. Work is only run when there is
 104  * some pages to free.
 105  * @small_allocation: Limit in number of pages what is small allocation.
 106  *
 107  * @pools: All pool objects in use.
 108  **/
 109 struct ttm_pool_manager {
 110         unsigned int kobj_ref;
 111         eventhandler_tag lowmem_handler;
 112         struct ttm_pool_opts    options;
 113
 114         union {
 115                 struct ttm_page_pool    u_pools[NUM_POOLS];
 116                 struct _utag {
 117                         struct ttm_page_pool    u_wc_pool;
 118                         struct ttm_page_pool    u_uc_pool;
 119                         struct ttm_page_pool    u_wc_pool_dma32;
 120                         struct ttm_page_pool    u_uc_pool_dma32;
 121                 } _ut;
 122         } _u;
 123 };
 124
 125 #define pools _u.u_pools
 126 #define wc_pool _u._ut.u_wc_pool
 127 #define uc_pool _u._ut.u_uc_pool
 128 #define wc_pool_dma32 _u._ut.u_wc_pool_dma32
 129 #define uc_pool_dma32 _u._ut.u_uc_pool_dma32
 130
 131 MALLOC_DEFINE(M_TTM_POOLMGR, "ttm_poolmgr", "TTM Pool Manager");
 132
 133 static void
 134 ttm_vm_page_free(vm_page_t m)
 135 {
 136
 137         KASSERT(m->object == NULL, ("ttm page %p is owned", m));
 138         KASSERT(m->wire_count == 1, ("ttm lost wire %p", m));
 139         KASSERT((m->flags & PG_FICTITIOUS) != 0, ("ttm lost fictitious %p", m));
 140 #if 0
 141         KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("ttm got unmanaged %p", m));
 142         m->oflags |= VPO_UNMANAGED;
 143 #endif
 144         m->flags &= ~PG_FICTITIOUS;
 145         vm_page_busy_wait(m, FALSE, "ttmvpf");
 146         vm_page_wakeup(m);
 147         vm_page_free_contig(m, PAGE_SIZE);
 148         /*
 149         vm_page_unwire(m, 0);
 150         vm_page_free(m);
 151         */
 152 }
 153
 154 static vm_memattr_t
 155 ttm_caching_state_to_vm(enum ttm_caching_state cstate)
 156 {
 157
 158         switch (cstate) {
 159         case tt_uncached:
 160                 return (VM_MEMATTR_UNCACHEABLE);
 161         case tt_wc:
 162                 return (VM_MEMATTR_WRITE_COMBINING);
 163         case tt_cached:
 164                 return (VM_MEMATTR_WRITE_BACK);
 165         }
 166         panic("caching state %d\n", cstate);
 167 }
 168
 169 static void ttm_pool_kobj_release(struct ttm_pool_manager *m)
 170 {
 171
 172         drm_free(m, M_TTM_POOLMGR);
 173 }
 174
 175 #if 0
 176 /* XXXKIB sysctl */
 177 static ssize_t ttm_pool_store(struct ttm_pool_manager *m,
 178                 struct attribute *attr, const char *buffer, size_t size)
 179 {
 180         int chars;
 181         unsigned val;
 182         chars = sscanf(buffer, "%u", &val);
 183         if (chars == 0)
 184                 return size;
 185
 186         /* Convert kb to number of pages */
 187         val = val / (PAGE_SIZE >> 10);
 188
 189         if (attr == &ttm_page_pool_max)
 190                 m->options.max_size = val;
 191         else if (attr == &ttm_page_pool_small)
 192                 m->options.small = val;
 193         else if (attr == &ttm_page_pool_alloc_size) {
 194                 if (val > NUM_PAGES_TO_ALLOC*8) {
 195                         pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 196                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 197                                NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 198                         return size;
 199                 } else if (val > NUM_PAGES_TO_ALLOC) {
 200                         pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 201                                 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 202                 }
 203                 m->options.alloc_size = val;
 204         }
 205
 206         return size;
 207 }
 208
 209 static ssize_t ttm_pool_show(struct ttm_pool_manager *m,
 210                 struct attribute *attr, char *buffer)
 211 {
 212         unsigned val = 0;
 213
 214         if (attr == &ttm_page_pool_max)
 215                 val = m->options.max_size;
 216         else if (attr == &ttm_page_pool_small)
 217                 val = m->options.small;
 218         else if (attr == &ttm_page_pool_alloc_size)
 219                 val = m->options.alloc_size;
 220
 221         val = val * (PAGE_SIZE >> 10);
 222
 223         return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 224 }
 225 #endif
 226
 227 static struct ttm_pool_manager *_manager;
 228
 229 static int set_pages_array_wb(vm_page_t *pages, int addrinarray)
 230 {
 231         vm_page_t m;
 232         int i;
 233
 234         for (i = 0; i < addrinarray; i++) {
 235                 m = pages[i];
 236 #ifdef TTM_HAS_AGP
 237                 unmap_page_from_agp(m);
 238 #endif
 239                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_BACK);
 240         }
 241         return 0;
 242 }
 243
 244 static int set_pages_array_wc(vm_page_t *pages, int addrinarray)
 245 {
 246         vm_page_t m;
 247         int i;
 248
 249         for (i = 0; i < addrinarray; i++) {
 250                 m = pages[i];
 251 #ifdef TTM_HAS_AGP
 252                 map_page_into_agp(pages[i]);
 253 #endif
 254                 pmap_page_set_memattr(m, VM_MEMATTR_WRITE_COMBINING);
 255         }
 256         return 0;
 257 }
 258
 259 static int set_pages_array_uc(vm_page_t *pages, int addrinarray)
 260 {
 261         vm_page_t m;
 262         int i;
 263
 264         for (i = 0; i < addrinarray; i++) {
 265                 m = pages[i];
 266 #ifdef TTM_HAS_AGP
 267                 map_page_into_agp(pages[i]);
 268 #endif
 269                 pmap_page_set_memattr(m, VM_MEMATTR_UNCACHEABLE);
 270         }
 271         return 0;
 272 }
 273
 274 /**
 275  * Select the right pool or requested caching state and ttm flags. */
 276 static struct ttm_page_pool *ttm_get_pool(int flags,
 277                 enum ttm_caching_state cstate)
 278 {
 279         int pool_index;
 280
 281         if (cstate == tt_cached)
 282                 return NULL;
 283
 284         if (cstate == tt_wc)
 285                 pool_index = 0x0;
 286         else
 287                 pool_index = 0x1;
 288
 289         if (flags & TTM_PAGE_FLAG_DMA32)
 290                 pool_index |= 0x2;
 291
 292         return &_manager->pools[pool_index];
 293 }
 294
 295 /* set memory back to wb and free the pages. */
 296 static void ttm_pages_put(vm_page_t *pages, unsigned npages)
 297 {
 298         unsigned i;
 299
 300         /* Our VM handles vm memattr automatically on the page free. */
 301         if (set_pages_array_wb(pages, npages))
 302                 kprintf("[TTM] Failed to set %d pages to wb!\n", npages);
 303         for (i = 0; i < npages; ++i)
 304                 ttm_vm_page_free(pages[i]);
 305 }
 306
 307 static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
 308                 unsigned freed_pages)
 309 {
 310         pool->npages -= freed_pages;
 311         pool->nfrees += freed_pages;
 312 }
 313
 314 /**
 315  * Free pages from pool.
 316  *
 317  * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 318  * number of pages in one go.
 319  *
 320  * @pool: to free the pages from
 321  * @free_all: If set to true will free all pages in pool
 322  **/
 323 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
 324 {
 325         vm_page_t p, p1;
 326         vm_page_t *pages_to_free;
 327         unsigned freed_pages = 0,
 328                  npages_to_free = nr_free;
 329         unsigned i;
 330
 331         if (NUM_PAGES_TO_ALLOC < nr_free)
 332                 npages_to_free = NUM_PAGES_TO_ALLOC;
 333
 334         pages_to_free = kmalloc(npages_to_free * sizeof(vm_page_t),
 335             M_TEMP, M_WAITOK | M_ZERO);
 336
 337 restart:
 338         lockmgr(&pool->lock, LK_EXCLUSIVE);
 339
 340         TAILQ_FOREACH_REVERSE_MUTABLE(p, &pool->list, pglist, pageq, p1) {
 341                 if (freed_pages >= npages_to_free)
 342                         break;
 343
 344                 pages_to_free[freed_pages++] = p;
 345                 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 346                 if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 347                         /* remove range of pages from the pool */
 348                         for (i = 0; i < freed_pages; i++)
 349                                 TAILQ_REMOVE(&pool->list, pages_to_free[i], pageq);
 350
 351                         ttm_pool_update_free_locked(pool, freed_pages);
 352                         /**
 353                          * Because changing page caching is costly
 354                          * we unlock the pool to prevent stalling.
 355                          */
 356                         lockmgr(&pool->lock, LK_RELEASE);
 357
 358                         ttm_pages_put(pages_to_free, freed_pages);
 359                         if (likely(nr_free != FREE_ALL_PAGES))
 360                                 nr_free -= freed_pages;
 361
 362                         if (NUM_PAGES_TO_ALLOC >= nr_free)
 363                                 npages_to_free = nr_free;
 364                         else
 365                                 npages_to_free = NUM_PAGES_TO_ALLOC;
 366
 367                         freed_pages = 0;
 368
 369                         /* free all so restart the processing */
 370                         if (nr_free)
 371                                 goto restart;
 372
 373                         /* Not allowed to fall through or break because
 374                          * following context is inside spinlock while we are
 375                          * outside here.
 376                          */
 377                         goto out;
 378
 379                 }
 380         }
 381
 382         /* remove range of pages from the pool */
 383         if (freed_pages) {
 384                 for (i = 0; i < freed_pages; i++)
 385                         TAILQ_REMOVE(&pool->list, pages_to_free[i], pageq);
 386
 387                 ttm_pool_update_free_locked(pool, freed_pages);
 388                 nr_free -= freed_pages;
 389         }
 390
 391         lockmgr(&pool->lock, LK_RELEASE);
 392
 393         if (freed_pages)
 394                 ttm_pages_put(pages_to_free, freed_pages);
 395 out:
 396         drm_free(pages_to_free, M_TEMP);
 397         return nr_free;
 398 }
 399
 400 /* Get good estimation how many pages are free in pools */
 401 static int ttm_pool_get_num_unused_pages(void)
 402 {
 403         unsigned i;
 404         int total = 0;
 405         for (i = 0; i < NUM_POOLS; ++i)
 406                 total += _manager->pools[i].npages;
 407
 408         return total;
 409 }
 410
 411 /**
 412  * Callback for mm to request pool to reduce number of page held.
 413  */
 414 static int ttm_pool_mm_shrink(void *arg)
 415 {
 416         static unsigned int start_pool = 0;
 417         unsigned i;
 418         unsigned pool_offset = atomic_fetchadd_int(&start_pool, 1);
 419         struct ttm_page_pool *pool;
 420         int shrink_pages = 100; /* XXXKIB */
 421
 422         pool_offset = pool_offset % NUM_POOLS;
 423         /* select start pool in round robin fashion */
 424         for (i = 0; i < NUM_POOLS; ++i) {
 425                 unsigned nr_free = shrink_pages;
 426                 if (shrink_pages == 0)
 427                         break;
 428                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
 429                 shrink_pages = ttm_page_pool_free(pool, nr_free);
 430         }
 431         /* return estimated number of unused pages in pool */
 432         return ttm_pool_get_num_unused_pages();
 433 }
 434
 435 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 436 {
 437
 438         manager->lowmem_handler = EVENTHANDLER_REGISTER(vm_lowmem,
 439             ttm_pool_mm_shrink, manager, EVENTHANDLER_PRI_ANY);
 440 }
 441
 442 static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
 443 {
 444
 445         EVENTHANDLER_DEREGISTER(vm_lowmem, manager->lowmem_handler);
 446 }
 447
 448 static int ttm_set_pages_caching(vm_page_t *pages,
 449                 enum ttm_caching_state cstate, unsigned cpages)
 450 {
 451         int r = 0;
 452         /* Set page caching */
 453         switch (cstate) {
 454         case tt_uncached:
 455                 r = set_pages_array_uc(pages, cpages);
 456                 if (r)
 457                         kprintf("[TTM] Failed to set %d pages to uc!\n", cpages);
 458                 break;
 459         case tt_wc:
 460                 r = set_pages_array_wc(pages, cpages);
 461                 if (r)
 462                         kprintf("[TTM] Failed to set %d pages to wc!\n", cpages);
 463                 break;
 464         default:
 465                 break;
 466         }
 467         return r;
 468 }
 469
 470 /**
 471  * Free pages the pages that failed to change the caching state. If there is
 472  * any pages that have changed their caching state already put them to the
 473  * pool.
 474  */
 475 static void ttm_handle_caching_state_failure(struct pglist *pages,
 476                 int ttm_flags, enum ttm_caching_state cstate,
 477                 vm_page_t *failed_pages, unsigned cpages)
 478 {
 479         unsigned i;
 480         /* Failed pages have to be freed */
 481         for (i = 0; i < cpages; ++i) {
 482                 TAILQ_REMOVE(pages, failed_pages[i], pageq);
 483                 ttm_vm_page_free(failed_pages[i]);
 484         }
 485 }
 486
 487 /**
 488  * Allocate new pages with correct caching.
 489  *
 490  * This function is reentrant if caller updates count depending on number of
 491  * pages returned in pages array.
 492  */
 493 static int ttm_alloc_new_pages(struct pglist *pages, int ttm_alloc_flags,
 494                 int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 495 {
 496         vm_page_t *caching_array;
 497         vm_page_t p;
 498         int r = 0;
 499         unsigned i, cpages, aflags;
 500         unsigned max_cpages = min(count,
 501                         (unsigned)(PAGE_SIZE/sizeof(vm_page_t)));
 502
 503         aflags = VM_ALLOC_NORMAL |
 504             ((ttm_alloc_flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ?
 505             VM_ALLOC_ZERO : 0);
 506
 507         /* allocate array for page caching change */
 508         caching_array = kmalloc(max_cpages * sizeof(vm_page_t), M_TEMP,
 509             M_WAITOK | M_ZERO);
 510
 511         for (i = 0, cpages = 0; i < count; ++i) {
 512                 p = vm_page_alloc_contig(0,
 513                     (ttm_alloc_flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 514                     VM_MAX_ADDRESS, PAGE_SIZE, 0,
 515                     1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 516                 if (!p) {
 517                         kprintf("[TTM] Unable to get page %u\n", i);
 518
 519                         /* store already allocated pages in the pool after
 520                          * setting the caching state */
 521                         if (cpages) {
 522                                 r = ttm_set_pages_caching(caching_array,
 523                                                           cstate, cpages);
 524                                 if (r)
 525                                         ttm_handle_caching_state_failure(pages,
 526                                                 ttm_flags, cstate,
 527                                                 caching_array, cpages);
 528                         }
 529                         r = -ENOMEM;
 530                         goto out;
 531                 }
 532 #if 0
 533                 p->oflags &= ~VPO_UNMANAGED;
 534 #endif
 535                 p->flags |= PG_FICTITIOUS;
 536
 537 #ifdef CONFIG_HIGHMEM /* KIB: nop */
 538                 /* gfp flags of highmem page should never be dma32 so we
 539                  * we should be fine in such case
 540                  */
 541                 if (!PageHighMem(p))
 542 #endif
 543                 {
 544                         caching_array[cpages++] = p;
 545                         if (cpages == max_cpages) {
 546
 547                                 r = ttm_set_pages_caching(caching_array,
 548                                                 cstate, cpages);
 549                                 if (r) {
 550                                         ttm_handle_caching_state_failure(pages,
 551                                                 ttm_flags, cstate,
 552                                                 caching_array, cpages);
 553                                         goto out;
 554                                 }
 555                                 cpages = 0;
 556                         }
 557                 }
 558
 559                 TAILQ_INSERT_HEAD(pages, p, pageq);
 560         }
 561
 562         if (cpages) {
 563                 r = ttm_set_pages_caching(caching_array, cstate, cpages);
 564                 if (r)
 565                         ttm_handle_caching_state_failure(pages,
 566                                         ttm_flags, cstate,
 567                                         caching_array, cpages);
 568         }
 569 out:
 570         drm_free(caching_array, M_TEMP);
 571
 572         return r;
 573 }
 574
 575 /**
 576  * Fill the given pool if there aren't enough pages and the requested number of
 577  * pages is small.
 578  */
 579 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 580     int ttm_flags, enum ttm_caching_state cstate, unsigned count)
 581 {
 582         vm_page_t p;
 583         int r;
 584         unsigned cpages = 0;
 585         /**
 586          * Only allow one pool fill operation at a time.
 587          * If pool doesn't have enough pages for the allocation new pages are
 588          * allocated from outside of pool.
 589          */
 590         if (pool->fill_lock)
 591                 return;
 592
 593         pool->fill_lock = true;
 594
 595         /* If allocation request is small and there are not enough
 596          * pages in a pool we fill the pool up first. */
 597         if (count < _manager->options.small
 598                 && count > pool->npages) {
 599                 struct pglist new_pages;
 600                 unsigned alloc_size = _manager->options.alloc_size;
 601
 602                 /**
 603                  * Can't change page caching if in irqsave context. We have to
 604                  * drop the pool->lock.
 605                  */
 606                 lockmgr(&pool->lock, LK_RELEASE);
 607
 608                 TAILQ_INIT(&new_pages);
 609                 r = ttm_alloc_new_pages(&new_pages, pool->ttm_page_alloc_flags,
 610                     ttm_flags, cstate, alloc_size);
 611                 lockmgr(&pool->lock, LK_EXCLUSIVE);
 612
 613                 if (!r) {
 614                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 615                         ++pool->nrefills;
 616                         pool->npages += alloc_size;
 617                 } else {
 618                         kprintf("[TTM] Failed to fill pool (%p)\n", pool);
 619                         /* If we have any pages left put them to the pool. */
 620                         TAILQ_FOREACH(p, &pool->list, pageq) {
 621                                 ++cpages;
 622                         }
 623                         TAILQ_CONCAT(&pool->list, &new_pages, pageq);
 624                         pool->npages += cpages;
 625                 }
 626
 627         }
 628         pool->fill_lock = false;
 629 }
 630
 631 /**
 632  * Cut 'count' number of pages from the pool and put them on the return list.
 633  *
 634  * @return count of pages still required to fulfill the request.
 635  */
 636 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 637                                         struct pglist *pages,
 638                                         int ttm_flags,
 639                                         enum ttm_caching_state cstate,
 640                                         unsigned count)
 641 {
 642         vm_page_t p;
 643         unsigned i;
 644
 645         lockmgr(&pool->lock, LK_EXCLUSIVE);
 646         ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count);
 647
 648         if (count >= pool->npages) {
 649                 /* take all pages from the pool */
 650                 TAILQ_CONCAT(pages, &pool->list, pageq);
 651                 count -= pool->npages;
 652                 pool->npages = 0;
 653                 goto out;
 654         }
 655         for (i = 0; i < count; i++) {
 656                 p = TAILQ_FIRST(&pool->list);
 657                 TAILQ_REMOVE(&pool->list, p, pageq);
 658                 TAILQ_INSERT_TAIL(pages, p, pageq);
 659         }
 660         pool->npages -= count;
 661         count = 0;
 662 out:
 663         lockmgr(&pool->lock, LK_RELEASE);
 664         return count;
 665 }
 666
 667 /* Put all pages in pages list to correct pool to wait for reuse */
 668 static void ttm_put_pages(vm_page_t *pages, unsigned npages, int flags,
 669                           enum ttm_caching_state cstate)
 670 {
 671         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 672         unsigned i;
 673
 674         if (pool == NULL) {
 675                 /* No pool for this memory type so free the pages */
 676                 for (i = 0; i < npages; i++) {
 677                         if (pages[i]) {
 678                                 ttm_vm_page_free(pages[i]);
 679                                 pages[i] = NULL;
 680                         }
 681                 }
 682                 return;
 683         }
 684
 685         lockmgr(&pool->lock, LK_EXCLUSIVE);
 686         for (i = 0; i < npages; i++) {
 687                 if (pages[i]) {
 688                         TAILQ_INSERT_TAIL(&pool->list, pages[i], pageq);
 689                         pages[i] = NULL;
 690                         pool->npages++;
 691                 }
 692         }
 693         /* Check that we don't go over the pool limit */
 694         npages = 0;
 695         if (pool->npages > _manager->options.max_size) {
 696                 npages = pool->npages - _manager->options.max_size;
 697                 /* free at least NUM_PAGES_TO_ALLOC number of pages
 698                  * to reduce calls to set_memory_wb */
 699                 if (npages < NUM_PAGES_TO_ALLOC)
 700                         npages = NUM_PAGES_TO_ALLOC;
 701         }
 702         lockmgr(&pool->lock, LK_RELEASE);
 703         if (npages)
 704                 ttm_page_pool_free(pool, npages);
 705 }
 706
 707 /*
 708  * On success pages list will hold count number of correctly
 709  * cached pages.
 710  */
 711 static int ttm_get_pages(vm_page_t *pages, unsigned npages, int flags,
 712                          enum ttm_caching_state cstate)
 713 {
 714         struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
 715         struct pglist plist;
 716         vm_page_t p = NULL;
 717         int gfp_flags, aflags;
 718         unsigned count;
 719         int r;
 720
 721         aflags = VM_ALLOC_NORMAL |
 722             ((flags & TTM_PAGE_FLAG_ZERO_ALLOC) != 0 ? VM_ALLOC_ZERO : 0);
 723
 724         /* No pool for cached pages */
 725         if (pool == NULL) {
 726                 for (r = 0; r < npages; ++r) {
 727                         p = vm_page_alloc_contig(0,
 728                             (flags & TTM_PAGE_FLAG_DMA32) ? 0xffffffff :
 729                             VM_MAX_ADDRESS, PAGE_SIZE,
 730                             0, 1*PAGE_SIZE, ttm_caching_state_to_vm(cstate));
 731                         if (!p) {
 732                                 kprintf("[TTM] Unable to allocate page\n");
 733                                 return -ENOMEM;
 734                         }
 735 #if 0
 736                         p->oflags &= ~VPO_UNMANAGED;
 737 #endif
 738                         p->flags |= PG_FICTITIOUS;
 739                         pages[r] = p;
 740                 }
 741                 return 0;
 742         }
 743
 744         /* combine zero flag to pool flags */
 745         gfp_flags = flags | pool->ttm_page_alloc_flags;
 746
 747         /* First we take pages from the pool */
 748         TAILQ_INIT(&plist);
 749         npages = ttm_page_pool_get_pages(pool, &plist, flags, cstate, npages);
 750         count = 0;
 751         TAILQ_FOREACH(p, &plist, pageq) {
 752                 pages[count++] = p;
 753         }
 754
 755         /* clear the pages coming from the pool if requested */
 756         if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) {
 757                 TAILQ_FOREACH(p, &plist, pageq) {
 758                         pmap_zero_page(VM_PAGE_TO_PHYS(p));
 759                 }
 760         }
 761
 762         /* If pool didn't have enough pages allocate new one. */
 763         if (npages > 0) {
 764                 /* ttm_alloc_new_pages doesn't reference pool so we can run
 765                  * multiple requests in parallel.
 766                  **/
 767                 TAILQ_INIT(&plist);
 768                 r = ttm_alloc_new_pages(&plist, gfp_flags, flags, cstate,
 769                     npages);
 770                 TAILQ_FOREACH(p, &plist, pageq) {
 771                         pages[count++] = p;
 772                 }
 773                 if (r) {
 774                         /* If there is any pages in the list put them back to
 775                          * the pool. */
 776                         kprintf("[TTM] Failed to allocate extra pages for large request\n");
 777                         ttm_put_pages(pages, count, flags, cstate);
 778                         return r;
 779                 }
 780         }
 781
 782         return 0;
 783 }
 784
 785 static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
 786                                       char *name)
 787 {
 788         lockinit(&pool->lock, "ttmpool", 0, LK_CANRECURSE);
 789         pool->fill_lock = false;
 790         TAILQ_INIT(&pool->list);
 791         pool->npages = pool->nfrees = 0;
 792         pool->ttm_page_alloc_flags = flags;
 793         pool->name = name;
 794 }
 795
 796 int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
 797 {
 798
 799         if (_manager != NULL)
 800                 kprintf("[TTM] manager != NULL\n");
 801         kprintf("[TTM] Initializing pool allocator\n");
 802
 803         _manager = kmalloc(sizeof(*_manager), M_TTM_POOLMGR, M_WAITOK | M_ZERO);
 804
 805         ttm_page_pool_init_locked(&_manager->wc_pool, 0, "wc");
 806         ttm_page_pool_init_locked(&_manager->uc_pool, 0, "uc");
 807         ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
 808             TTM_PAGE_FLAG_DMA32, "wc dma");
 809         ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
 810             TTM_PAGE_FLAG_DMA32, "uc dma");
 811
 812         _manager->options.max_size = max_pages;
 813         _manager->options.small = SMALL_ALLOCATION;
 814         _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
 815
 816         refcount_init(&_manager->kobj_ref, 1);
 817         ttm_pool_mm_shrink_init(_manager);
 818
 819         return 0;
 820 }
 821
 822 void ttm_page_alloc_fini(void)
 823 {
 824         int i;
 825
 826         kprintf("[TTM] Finalizing pool allocator\n");
 827         ttm_pool_mm_shrink_fini(_manager);
 828
 829         for (i = 0; i < NUM_POOLS; ++i)
 830                 ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
 831
 832         if (refcount_release(&_manager->kobj_ref))
 833                 ttm_pool_kobj_release(_manager);
 834         _manager = NULL;
 835 }
 836
 837 int ttm_pool_populate(struct ttm_tt *ttm)
 838 {
 839         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 840         unsigned i;
 841         int ret;
 842
 843         if (ttm->state != tt_unpopulated)
 844                 return 0;
 845
 846         for (i = 0; i < ttm->num_pages; ++i) {
 847                 ret = ttm_get_pages(&ttm->pages[i], 1,
 848                                     ttm->page_flags,
 849                                     ttm->caching_state);
 850                 if (ret != 0) {
 851                         ttm_pool_unpopulate(ttm);
 852                         return -ENOMEM;
 853                 }
 854
 855                 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 856                                                 false, false);
 857                 if (unlikely(ret != 0)) {
 858                         ttm_pool_unpopulate(ttm);
 859                         return -ENOMEM;
 860                 }
 861         }
 862
 863         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 864                 ret = ttm_tt_swapin(ttm);
 865                 if (unlikely(ret != 0)) {
 866                         ttm_pool_unpopulate(ttm);
 867                         return ret;
 868                 }
 869         }
 870
 871         ttm->state = tt_unbound;
 872         return 0;
 873 }
 874
 875 void ttm_pool_unpopulate(struct ttm_tt *ttm)
 876 {
 877         unsigned i;
 878
 879         for (i = 0; i < ttm->num_pages; ++i) {
 880                 if (ttm->pages[i]) {
 881                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 882                                                  ttm->pages[i]);
 883                         ttm_put_pages(&ttm->pages[i], 1,
 884                                       ttm->page_flags,
 885                                       ttm->caching_state);
 886                 }
 887         }
 888         ttm->state = tt_unpopulated;
 889 }
 890
 891 #if 0
 892 /* XXXKIB sysctl */
 893 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 894 {
 895         struct ttm_page_pool *p;
 896         unsigned i;
 897         char *h[] = {"pool", "refills", "pages freed", "size"};
 898         if (!_manager) {
 899                 seq_printf(m, "No pool allocator running.\n");
 900                 return 0;
 901         }
 902         seq_printf(m, "%6s %12s %13s %8s\n",
 903                         h[0], h[1], h[2], h[3]);
 904         for (i = 0; i < NUM_POOLS; ++i) {
 905                 p = &_manager->pools[i];
 906
 907                 seq_printf(m, "%6s %12ld %13ld %8d\n",
 908                                 p->name, p->nrefills,
 909                                 p->nfrees, p->npages);
 910         }
 911         return 0;
 912 }
 913 #endif