| 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 | /* simple list based uncached page pool |
| 29 | * - Pool collects resently freed pages for reuse |
| 30 | * - Use page->lru to keep a free list |
| 31 | * - doesn't track currently in use pages |
| 32 | */ |
| 33 | #include <linux/list.h> |
| 34 | #include <linux/spinlock.h> |
| 35 | #include <linux/highmem.h> |
| 36 | #include <linux/mm_types.h> |
| 37 | #include <linux/module.h> |
| 38 | #include <linux/mm.h> |
| 39 | #include <linux/seq_file.h> /* for seq_printf */ |
| 40 | |
| 41 | #include <asm/atomic.h> |
| 42 | #include <asm/agp.h> |
| 43 | |
| 44 | #include "ttm/ttm_bo_driver.h" |
| 45 | #include "ttm/ttm_page_alloc.h" |
| 46 | |
| 47 | |
| 48 | #define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *)) |
| 49 | #define SMALL_ALLOCATION 16 |
| 50 | #define FREE_ALL_PAGES (~0U) |
| 51 | /* times are in msecs */ |
| 52 | #define PAGE_FREE_INTERVAL 1000 |
| 53 | |
| 54 | /** |
| 55 | * struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages. |
| 56 | * |
| 57 | * @lock: Protects the shared pool from concurrnet access. Must be used with |
| 58 | * irqsave/irqrestore variants because pool allocator maybe called from |
| 59 | * delayed work. |
| 60 | * @fill_lock: Prevent concurrent calls to fill. |
| 61 | * @list: Pool of free uc/wc pages for fast reuse. |
| 62 | * @gfp_flags: Flags to pass for alloc_page. |
| 63 | * @npages: Number of pages in pool. |
| 64 | */ |
| 65 | struct ttm_page_pool { |
| 66 | spinlock_t lock; |
| 67 | bool fill_lock; |
| 68 | struct list_head list; |
| 69 | int gfp_flags; |
| 70 | unsigned npages; |
| 71 | char *name; |
| 72 | unsigned long nfrees; |
| 73 | unsigned long nrefills; |
| 74 | }; |
| 75 | |
| 76 | /** |
| 77 | * Limits for the pool. They are handled without locks because only place where |
| 78 | * they may change is in sysfs store. They won't have immediate effect anyway |
| 79 | * so forcing serialiazation to access them is pointless. |
| 80 | */ |
| 81 | |
| 82 | struct ttm_pool_opts { |
| 83 | unsigned alloc_size; |
| 84 | unsigned max_size; |
| 85 | unsigned small; |
| 86 | }; |
| 87 | |
| 88 | #define NUM_POOLS 4 |
| 89 | |
| 90 | /** |
| 91 | * struct ttm_pool_manager - Holds memory pools for fst allocation |
| 92 | * |
| 93 | * Manager is read only object for pool code so it doesn't need locking. |
| 94 | * |
| 95 | * @free_interval: minimum number of jiffies between freeing pages from pool. |
| 96 | * @page_alloc_inited: reference counting for pool allocation. |
| 97 | * @work: Work that is used to shrink the pool. Work is only run when there is |
| 98 | * some pages to free. |
| 99 | * @small_allocation: Limit in number of pages what is small allocation. |
| 100 | * |
| 101 | * @pools: All pool objects in use. |
| 102 | **/ |
| 103 | struct ttm_pool_manager { |
| 104 | struct kobject kobj; |
| 105 | struct shrinker mm_shrink; |
| 106 | atomic_t page_alloc_inited; |
| 107 | struct ttm_pool_opts options; |
| 108 | |
| 109 | union { |
| 110 | struct ttm_page_pool pools[NUM_POOLS]; |
| 111 | struct { |
| 112 | struct ttm_page_pool wc_pool; |
| 113 | struct ttm_page_pool uc_pool; |
| 114 | struct ttm_page_pool wc_pool_dma32; |
| 115 | struct ttm_page_pool uc_pool_dma32; |
| 116 | } ; |
| 117 | }; |
| 118 | }; |
| 119 | |
| 120 | static struct attribute ttm_page_pool_max = { |
| 121 | .name = "pool_max_size", |
| 122 | .mode = S_IRUGO | S_IWUSR |
| 123 | }; |
| 124 | static struct attribute ttm_page_pool_small = { |
| 125 | .name = "pool_small_allocation", |
| 126 | .mode = S_IRUGO | S_IWUSR |
| 127 | }; |
| 128 | static struct attribute ttm_page_pool_alloc_size = { |
| 129 | .name = "pool_allocation_size", |
| 130 | .mode = S_IRUGO | S_IWUSR |
| 131 | }; |
| 132 | |
| 133 | static struct attribute *ttm_pool_attrs[] = { |
| 134 | &ttm_page_pool_max, |
| 135 | &ttm_page_pool_small, |
| 136 | &ttm_page_pool_alloc_size, |
| 137 | NULL |
| 138 | }; |
| 139 | |
| 140 | static void ttm_pool_kobj_release(struct kobject *kobj) |
| 141 | { |
| 142 | struct ttm_pool_manager *m = |
| 143 | container_of(kobj, struct ttm_pool_manager, kobj); |
| 144 | (void)m; |
| 145 | } |
| 146 | |
| 147 | static ssize_t ttm_pool_store(struct kobject *kobj, |
| 148 | struct attribute *attr, const char *buffer, size_t size) |
| 149 | { |
| 150 | struct ttm_pool_manager *m = |
| 151 | container_of(kobj, struct ttm_pool_manager, kobj); |
| 152 | int chars; |
| 153 | unsigned val; |
| 154 | chars = sscanf(buffer, "%u", &val); |
| 155 | if (chars == 0) |
| 156 | return size; |
| 157 | |
| 158 | /* Convert kb to number of pages */ |
| 159 | val = val / (PAGE_SIZE >> 10); |
| 160 | |
| 161 | if (attr == &ttm_page_pool_max) |
| 162 | m->options.max_size = val; |
| 163 | else if (attr == &ttm_page_pool_small) |
| 164 | m->options.small = val; |
| 165 | else if (attr == &ttm_page_pool_alloc_size) { |
| 166 | if (val > NUM_PAGES_TO_ALLOC*8) { |
| 167 | printk(KERN_ERR "[ttm] Setting allocation size to %lu " |
| 168 | "is not allowed. Recomended size is " |
| 169 | "%lu\n", |
| 170 | NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7), |
| 171 | NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); |
| 172 | return size; |
| 173 | } else if (val > NUM_PAGES_TO_ALLOC) { |
| 174 | printk(KERN_WARNING "[ttm] Setting allocation size to " |
| 175 | "larger than %lu is not recomended.\n", |
| 176 | NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); |
| 177 | } |
| 178 | m->options.alloc_size = val; |
| 179 | } |
| 180 | |
| 181 | return size; |
| 182 | } |
| 183 | |
| 184 | static ssize_t ttm_pool_show(struct kobject *kobj, |
| 185 | struct attribute *attr, char *buffer) |
| 186 | { |
| 187 | struct ttm_pool_manager *m = |
| 188 | container_of(kobj, struct ttm_pool_manager, kobj); |
| 189 | unsigned val = 0; |
| 190 | |
| 191 | if (attr == &ttm_page_pool_max) |
| 192 | val = m->options.max_size; |
| 193 | else if (attr == &ttm_page_pool_small) |
| 194 | val = m->options.small; |
| 195 | else if (attr == &ttm_page_pool_alloc_size) |
| 196 | val = m->options.alloc_size; |
| 197 | |
| 198 | val = val * (PAGE_SIZE >> 10); |
| 199 | |
| 200 | return snprintf(buffer, PAGE_SIZE, "%u\n", val); |
| 201 | } |
| 202 | |
| 203 | static const struct sysfs_ops ttm_pool_sysfs_ops = { |
| 204 | .show = &ttm_pool_show, |
| 205 | .store = &ttm_pool_store, |
| 206 | }; |
| 207 | |
| 208 | static struct kobj_type ttm_pool_kobj_type = { |
| 209 | .release = &ttm_pool_kobj_release, |
| 210 | .sysfs_ops = &ttm_pool_sysfs_ops, |
| 211 | .default_attrs = ttm_pool_attrs, |
| 212 | }; |
| 213 | |
| 214 | static struct ttm_pool_manager _manager = { |
| 215 | .page_alloc_inited = ATOMIC_INIT(0) |
| 216 | }; |
| 217 | |
| 218 | #ifndef CONFIG_X86 |
| 219 | static int set_pages_array_wb(struct page **pages, int addrinarray) |
| 220 | { |
| 221 | #ifdef TTM_HAS_AGP |
| 222 | int i; |
| 223 | |
| 224 | for (i = 0; i < addrinarray; i++) |
| 225 | unmap_page_from_agp(pages[i]); |
| 226 | #endif |
| 227 | return 0; |
| 228 | } |
| 229 | |
| 230 | static int set_pages_array_wc(struct page **pages, int addrinarray) |
| 231 | { |
| 232 | #ifdef TTM_HAS_AGP |
| 233 | int i; |
| 234 | |
| 235 | for (i = 0; i < addrinarray; i++) |
| 236 | map_page_into_agp(pages[i]); |
| 237 | #endif |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static int set_pages_array_uc(struct page **pages, int addrinarray) |
| 242 | { |
| 243 | #ifdef TTM_HAS_AGP |
| 244 | int i; |
| 245 | |
| 246 | for (i = 0; i < addrinarray; i++) |
| 247 | map_page_into_agp(pages[i]); |
| 248 | #endif |
| 249 | return 0; |
| 250 | } |
| 251 | #endif |
| 252 | |
| 253 | /** |
| 254 | * Select the right pool or requested caching state and ttm flags. */ |
| 255 | static struct ttm_page_pool *ttm_get_pool(int flags, |
| 256 | enum ttm_caching_state cstate) |
| 257 | { |
| 258 | int pool_index; |
| 259 | |
| 260 | if (cstate == tt_cached) |
| 261 | return NULL; |
| 262 | |
| 263 | if (cstate == tt_wc) |
| 264 | pool_index = 0x0; |
| 265 | else |
| 266 | pool_index = 0x1; |
| 267 | |
| 268 | if (flags & TTM_PAGE_FLAG_DMA32) |
| 269 | pool_index |= 0x2; |
| 270 | |
| 271 | return &_manager.pools[pool_index]; |
| 272 | } |
| 273 | |
| 274 | /* set memory back to wb and free the pages. */ |
| 275 | static void ttm_pages_put(struct page *pages[], unsigned npages) |
| 276 | { |
| 277 | unsigned i; |
| 278 | if (set_pages_array_wb(pages, npages)) |
| 279 | printk(KERN_ERR "[ttm] Failed to set %d pages to wb!\n", |
| 280 | npages); |
| 281 | for (i = 0; i < npages; ++i) |
| 282 | __free_page(pages[i]); |
| 283 | } |
| 284 | |
| 285 | static void ttm_pool_update_free_locked(struct ttm_page_pool *pool, |
| 286 | unsigned freed_pages) |
| 287 | { |
| 288 | pool->npages -= freed_pages; |
| 289 | pool->nfrees += freed_pages; |
| 290 | } |
| 291 | |
| 292 | /** |
| 293 | * Free pages from pool. |
| 294 | * |
| 295 | * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC |
| 296 | * number of pages in one go. |
| 297 | * |
| 298 | * @pool: to free the pages from |
| 299 | * @free_all: If set to true will free all pages in pool |
| 300 | **/ |
| 301 | static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free) |
| 302 | { |
| 303 | unsigned long irq_flags; |
| 304 | struct page *p; |
| 305 | struct page **pages_to_free; |
| 306 | unsigned freed_pages = 0, |
| 307 | npages_to_free = nr_free; |
| 308 | |
| 309 | if (NUM_PAGES_TO_ALLOC < nr_free) |
| 310 | npages_to_free = NUM_PAGES_TO_ALLOC; |
| 311 | |
| 312 | pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), |
| 313 | GFP_KERNEL); |
| 314 | if (!pages_to_free) { |
| 315 | printk(KERN_ERR "Failed to allocate memory for pool free operation.\n"); |
| 316 | return 0; |
| 317 | } |
| 318 | |
| 319 | restart: |
| 320 | spin_lock_irqsave(&pool->lock, irq_flags); |
| 321 | |
| 322 | list_for_each_entry_reverse(p, &pool->list, lru) { |
| 323 | if (freed_pages >= npages_to_free) |
| 324 | break; |
| 325 | |
| 326 | pages_to_free[freed_pages++] = p; |
| 327 | /* We can only remove NUM_PAGES_TO_ALLOC at a time. */ |
| 328 | if (freed_pages >= NUM_PAGES_TO_ALLOC) { |
| 329 | /* remove range of pages from the pool */ |
| 330 | __list_del(p->lru.prev, &pool->list); |
| 331 | |
| 332 | ttm_pool_update_free_locked(pool, freed_pages); |
| 333 | /** |
| 334 | * Because changing page caching is costly |
| 335 | * we unlock the pool to prevent stalling. |
| 336 | */ |
| 337 | spin_unlock_irqrestore(&pool->lock, irq_flags); |
| 338 | |
| 339 | ttm_pages_put(pages_to_free, freed_pages); |
| 340 | if (likely(nr_free != FREE_ALL_PAGES)) |
| 341 | nr_free -= freed_pages; |
| 342 | |
| 343 | if (NUM_PAGES_TO_ALLOC >= nr_free) |
| 344 | npages_to_free = nr_free; |
| 345 | else |
| 346 | npages_to_free = NUM_PAGES_TO_ALLOC; |
| 347 | |
| 348 | freed_pages = 0; |
| 349 | |
| 350 | /* free all so restart the processing */ |
| 351 | if (nr_free) |
| 352 | goto restart; |
| 353 | |
| 354 | /* Not allowed to fall tough or break because |
| 355 | * following context is inside spinlock while we are |
| 356 | * outside here. |
| 357 | */ |
| 358 | goto out; |
| 359 | |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | /* remove range of pages from the pool */ |
| 364 | if (freed_pages) { |
| 365 | __list_del(&p->lru, &pool->list); |
| 366 | |
| 367 | ttm_pool_update_free_locked(pool, freed_pages); |
| 368 | nr_free -= freed_pages; |
| 369 | } |
| 370 | |
| 371 | spin_unlock_irqrestore(&pool->lock, irq_flags); |
| 372 | |
| 373 | if (freed_pages) |
| 374 | ttm_pages_put(pages_to_free, freed_pages); |
| 375 | out: |
| 376 | kfree(pages_to_free); |
| 377 | return nr_free; |
| 378 | } |
| 379 | |
| 380 | /* Get good estimation how many pages are free in pools */ |
| 381 | static int ttm_pool_get_num_unused_pages(void) |
| 382 | { |
| 383 | unsigned i; |
| 384 | int total = 0; |
| 385 | for (i = 0; i < NUM_POOLS; ++i) |
| 386 | total += _manager.pools[i].npages; |
| 387 | |
| 388 | return total; |
| 389 | } |
| 390 | |
| 391 | /** |
| 392 | * Calback for mm to request pool to reduce number of page held. |
| 393 | */ |
| 394 | static int ttm_pool_mm_shrink(int shrink_pages, gfp_t gfp_mask) |
| 395 | { |
| 396 | static atomic_t start_pool = ATOMIC_INIT(0); |
| 397 | unsigned i; |
| 398 | unsigned pool_offset = atomic_add_return(1, &start_pool); |
| 399 | struct ttm_page_pool *pool; |
| 400 | |
| 401 | pool_offset = pool_offset % NUM_POOLS; |
| 402 | /* select start pool in round robin fashion */ |
| 403 | for (i = 0; i < NUM_POOLS; ++i) { |
| 404 | unsigned nr_free = shrink_pages; |
| 405 | if (shrink_pages == 0) |
| 406 | break; |
| 407 | pool = &_manager.pools[(i + pool_offset)%NUM_POOLS]; |
| 408 | shrink_pages = ttm_page_pool_free(pool, nr_free); |
| 409 | } |
| 410 | /* return estimated number of unused pages in pool */ |
| 411 | return ttm_pool_get_num_unused_pages(); |
| 412 | } |
| 413 | |
| 414 | static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager) |
| 415 | { |
| 416 | manager->mm_shrink.shrink = &ttm_pool_mm_shrink; |
| 417 | manager->mm_shrink.seeks = 1; |
| 418 | register_shrinker(&manager->mm_shrink); |
| 419 | } |
| 420 | |
| 421 | static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager) |
| 422 | { |
| 423 | unregister_shrinker(&manager->mm_shrink); |
| 424 | } |
| 425 | |
| 426 | static int ttm_set_pages_caching(struct page **pages, |
| 427 | enum ttm_caching_state cstate, unsigned cpages) |
| 428 | { |
| 429 | int r = 0; |
| 430 | /* Set page caching */ |
| 431 | switch (cstate) { |
| 432 | case tt_uncached: |
| 433 | r = set_pages_array_uc(pages, cpages); |
| 434 | if (r) |
| 435 | printk(KERN_ERR "[ttm] Failed to set %d pages to uc!\n", |
| 436 | cpages); |
| 437 | break; |
| 438 | case tt_wc: |
| 439 | r = set_pages_array_wc(pages, cpages); |
| 440 | if (r) |
| 441 | printk(KERN_ERR "[ttm] Failed to set %d pages to wc!\n", |
| 442 | cpages); |
| 443 | break; |
| 444 | default: |
| 445 | break; |
| 446 | } |
| 447 | return r; |
| 448 | } |
| 449 | |
| 450 | /** |
| 451 | * Free pages the pages that failed to change the caching state. If there is |
| 452 | * any pages that have changed their caching state already put them to the |
| 453 | * pool. |
| 454 | */ |
| 455 | static void ttm_handle_caching_state_failure(struct list_head *pages, |
| 456 | int ttm_flags, enum ttm_caching_state cstate, |
| 457 | struct page **failed_pages, unsigned cpages) |
| 458 | { |
| 459 | unsigned i; |
| 460 | /* Failed pages has to be reed */ |
| 461 | for (i = 0; i < cpages; ++i) { |
| 462 | list_del(&failed_pages[i]->lru); |
| 463 | __free_page(failed_pages[i]); |
| 464 | } |
| 465 | } |
| 466 | |
| 467 | /** |
| 468 | * Allocate new pages with correct caching. |
| 469 | * |
| 470 | * This function is reentrant if caller updates count depending on number of |
| 471 | * pages returned in pages array. |
| 472 | */ |
| 473 | static int ttm_alloc_new_pages(struct list_head *pages, int gfp_flags, |
| 474 | int ttm_flags, enum ttm_caching_state cstate, unsigned count) |
| 475 | { |
| 476 | struct page **caching_array; |
| 477 | struct page *p; |
| 478 | int r = 0; |
| 479 | unsigned i, cpages; |
| 480 | unsigned max_cpages = min(count, |
| 481 | (unsigned)(PAGE_SIZE/sizeof(struct page *))); |
| 482 | |
| 483 | /* allocate array for page caching change */ |
| 484 | caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL); |
| 485 | |
| 486 | if (!caching_array) { |
| 487 | printk(KERN_ERR "[ttm] unable to allocate table for new pages."); |
| 488 | return -ENOMEM; |
| 489 | } |
| 490 | |
| 491 | for (i = 0, cpages = 0; i < count; ++i) { |
| 492 | p = alloc_page(gfp_flags); |
| 493 | |
| 494 | if (!p) { |
| 495 | printk(KERN_ERR "[ttm] unable to get page %u\n", i); |
| 496 | |
| 497 | /* store already allocated pages in the pool after |
| 498 | * setting the caching state */ |
| 499 | if (cpages) { |
| 500 | r = ttm_set_pages_caching(caching_array, cstate, cpages); |
| 501 | if (r) |
| 502 | ttm_handle_caching_state_failure(pages, |
| 503 | ttm_flags, cstate, |
| 504 | caching_array, cpages); |
| 505 | } |
| 506 | r = -ENOMEM; |
| 507 | goto out; |
| 508 | } |
| 509 | |
| 510 | #ifdef CONFIG_HIGHMEM |
| 511 | /* gfp flags of highmem page should never be dma32 so we |
| 512 | * we should be fine in such case |
| 513 | */ |
| 514 | if (!PageHighMem(p)) |
| 515 | #endif |
| 516 | { |
| 517 | caching_array[cpages++] = p; |
| 518 | if (cpages == max_cpages) { |
| 519 | |
| 520 | r = ttm_set_pages_caching(caching_array, |
| 521 | cstate, cpages); |
| 522 | if (r) { |
| 523 | ttm_handle_caching_state_failure(pages, |
| 524 | ttm_flags, cstate, |
| 525 | caching_array, cpages); |
| 526 | goto out; |
| 527 | } |
| 528 | cpages = 0; |
| 529 | } |
| 530 | } |
| 531 | |
| 532 | list_add(&p->lru, pages); |
| 533 | } |
| 534 | |
| 535 | if (cpages) { |
| 536 | r = ttm_set_pages_caching(caching_array, cstate, cpages); |
| 537 | if (r) |
| 538 | ttm_handle_caching_state_failure(pages, |
| 539 | ttm_flags, cstate, |
| 540 | caching_array, cpages); |
| 541 | } |
| 542 | out: |
| 543 | kfree(caching_array); |
| 544 | |
| 545 | return r; |
| 546 | } |
| 547 | |
| 548 | /** |
| 549 | * Fill the given pool if there isn't enough pages and requested number of |
| 550 | * pages is small. |
| 551 | */ |
| 552 | static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool, |
| 553 | int ttm_flags, enum ttm_caching_state cstate, unsigned count, |
| 554 | unsigned long *irq_flags) |
| 555 | { |
| 556 | struct page *p; |
| 557 | int r; |
| 558 | unsigned cpages = 0; |
| 559 | /** |
| 560 | * Only allow one pool fill operation at a time. |
| 561 | * If pool doesn't have enough pages for the allocation new pages are |
| 562 | * allocated from outside of pool. |
| 563 | */ |
| 564 | if (pool->fill_lock) |
| 565 | return; |
| 566 | |
| 567 | pool->fill_lock = true; |
| 568 | |
| 569 | /* If allocation request is small and there is not enough |
| 570 | * pages in pool we fill the pool first */ |
| 571 | if (count < _manager.options.small |
| 572 | && count > pool->npages) { |
| 573 | struct list_head new_pages; |
| 574 | unsigned alloc_size = _manager.options.alloc_size; |
| 575 | |
| 576 | /** |
| 577 | * Can't change page caching if in irqsave context. We have to |
| 578 | * drop the pool->lock. |
| 579 | */ |
| 580 | spin_unlock_irqrestore(&pool->lock, *irq_flags); |
| 581 | |
| 582 | INIT_LIST_HEAD(&new_pages); |
| 583 | r = ttm_alloc_new_pages(&new_pages, pool->gfp_flags, ttm_flags, |
| 584 | cstate, alloc_size); |
| 585 | spin_lock_irqsave(&pool->lock, *irq_flags); |
| 586 | |
| 587 | if (!r) { |
| 588 | list_splice(&new_pages, &pool->list); |
| 589 | ++pool->nrefills; |
| 590 | pool->npages += alloc_size; |
| 591 | } else { |
| 592 | printk(KERN_ERR "[ttm] Failed to fill pool (%p).", pool); |
| 593 | /* If we have any pages left put them to the pool. */ |
| 594 | list_for_each_entry(p, &pool->list, lru) { |
| 595 | ++cpages; |
| 596 | } |
| 597 | list_splice(&new_pages, &pool->list); |
| 598 | pool->npages += cpages; |
| 599 | } |
| 600 | |
| 601 | } |
| 602 | pool->fill_lock = false; |
| 603 | } |
| 604 | |
| 605 | /** |
| 606 | * Cut count nubmer of pages from the pool and put them to return list |
| 607 | * |
| 608 | * @return count of pages still to allocate to fill the request. |
| 609 | */ |
| 610 | static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool, |
| 611 | struct list_head *pages, int ttm_flags, |
| 612 | enum ttm_caching_state cstate, unsigned count) |
| 613 | { |
| 614 | unsigned long irq_flags; |
| 615 | struct list_head *p; |
| 616 | unsigned i; |
| 617 | |
| 618 | spin_lock_irqsave(&pool->lock, irq_flags); |
| 619 | ttm_page_pool_fill_locked(pool, ttm_flags, cstate, count, &irq_flags); |
| 620 | |
| 621 | if (count >= pool->npages) { |
| 622 | /* take all pages from the pool */ |
| 623 | list_splice_init(&pool->list, pages); |
| 624 | count -= pool->npages; |
| 625 | pool->npages = 0; |
| 626 | goto out; |
| 627 | } |
| 628 | /* find the last pages to include for requested number of pages. Split |
| 629 | * pool to begin and halves to reduce search space. */ |
| 630 | if (count <= pool->npages/2) { |
| 631 | i = 0; |
| 632 | list_for_each(p, &pool->list) { |
| 633 | if (++i == count) |
| 634 | break; |
| 635 | } |
| 636 | } else { |
| 637 | i = pool->npages + 1; |
| 638 | list_for_each_prev(p, &pool->list) { |
| 639 | if (--i == count) |
| 640 | break; |
| 641 | } |
| 642 | } |
| 643 | /* Cut count number of pages from pool */ |
| 644 | list_cut_position(pages, &pool->list, p); |
| 645 | pool->npages -= count; |
| 646 | count = 0; |
| 647 | out: |
| 648 | spin_unlock_irqrestore(&pool->lock, irq_flags); |
| 649 | return count; |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | * On success pages list will hold count number of correctly |
| 654 | * cached pages. |
| 655 | */ |
| 656 | int ttm_get_pages(struct list_head *pages, int flags, |
| 657 | enum ttm_caching_state cstate, unsigned count) |
| 658 | { |
| 659 | struct ttm_page_pool *pool = ttm_get_pool(flags, cstate); |
| 660 | struct page *p = NULL; |
| 661 | int gfp_flags = 0; |
| 662 | int r; |
| 663 | |
| 664 | /* set zero flag for page allocation if required */ |
| 665 | if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) |
| 666 | gfp_flags |= __GFP_ZERO; |
| 667 | |
| 668 | /* No pool for cached pages */ |
| 669 | if (pool == NULL) { |
| 670 | if (flags & TTM_PAGE_FLAG_DMA32) |
| 671 | gfp_flags |= GFP_DMA32; |
| 672 | else |
| 673 | gfp_flags |= __GFP_HIGHMEM; |
| 674 | |
| 675 | for (r = 0; r < count; ++r) { |
| 676 | p = alloc_page(gfp_flags); |
| 677 | if (!p) { |
| 678 | |
| 679 | printk(KERN_ERR "[ttm] unable to allocate page."); |
| 680 | return -ENOMEM; |
| 681 | } |
| 682 | |
| 683 | list_add(&p->lru, pages); |
| 684 | } |
| 685 | return 0; |
| 686 | } |
| 687 | |
| 688 | |
| 689 | /* combine zero flag to pool flags */ |
| 690 | gfp_flags |= pool->gfp_flags; |
| 691 | |
| 692 | /* First we take pages from the pool */ |
| 693 | count = ttm_page_pool_get_pages(pool, pages, flags, cstate, count); |
| 694 | |
| 695 | /* clear the pages coming from the pool if requested */ |
| 696 | if (flags & TTM_PAGE_FLAG_ZERO_ALLOC) { |
| 697 | list_for_each_entry(p, pages, lru) { |
| 698 | clear_page(page_address(p)); |
| 699 | } |
| 700 | } |
| 701 | |
| 702 | /* If pool didn't have enough pages allocate new one. */ |
| 703 | if (count > 0) { |
| 704 | /* ttm_alloc_new_pages doesn't reference pool so we can run |
| 705 | * multiple requests in parallel. |
| 706 | **/ |
| 707 | r = ttm_alloc_new_pages(pages, gfp_flags, flags, cstate, count); |
| 708 | if (r) { |
| 709 | /* If there is any pages in the list put them back to |
| 710 | * the pool. */ |
| 711 | printk(KERN_ERR "[ttm] Failed to allocate extra pages " |
| 712 | "for large request."); |
| 713 | ttm_put_pages(pages, 0, flags, cstate); |
| 714 | return r; |
| 715 | } |
| 716 | } |
| 717 | |
| 718 | |
| 719 | return 0; |
| 720 | } |
| 721 | |
| 722 | /* Put all pages in pages list to correct pool to wait for reuse */ |
| 723 | void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags, |
| 724 | enum ttm_caching_state cstate) |
| 725 | { |
| 726 | unsigned long irq_flags; |
| 727 | struct ttm_page_pool *pool = ttm_get_pool(flags, cstate); |
| 728 | struct page *p, *tmp; |
| 729 | |
| 730 | if (pool == NULL) { |
| 731 | /* No pool for this memory type so free the pages */ |
| 732 | |
| 733 | list_for_each_entry_safe(p, tmp, pages, lru) { |
| 734 | __free_page(p); |
| 735 | } |
| 736 | /* Make the pages list empty */ |
| 737 | INIT_LIST_HEAD(pages); |
| 738 | return; |
| 739 | } |
| 740 | if (page_count == 0) { |
| 741 | list_for_each_entry_safe(p, tmp, pages, lru) { |
| 742 | ++page_count; |
| 743 | } |
| 744 | } |
| 745 | |
| 746 | spin_lock_irqsave(&pool->lock, irq_flags); |
| 747 | list_splice_init(pages, &pool->list); |
| 748 | pool->npages += page_count; |
| 749 | /* Check that we don't go over the pool limit */ |
| 750 | page_count = 0; |
| 751 | if (pool->npages > _manager.options.max_size) { |
| 752 | page_count = pool->npages - _manager.options.max_size; |
| 753 | /* free at least NUM_PAGES_TO_ALLOC number of pages |
| 754 | * to reduce calls to set_memory_wb */ |
| 755 | if (page_count < NUM_PAGES_TO_ALLOC) |
| 756 | page_count = NUM_PAGES_TO_ALLOC; |
| 757 | } |
| 758 | spin_unlock_irqrestore(&pool->lock, irq_flags); |
| 759 | if (page_count) |
| 760 | ttm_page_pool_free(pool, page_count); |
| 761 | } |
| 762 | |
| 763 | static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags, |
| 764 | char *name) |
| 765 | { |
| 766 | spin_lock_init(&pool->lock); |
| 767 | pool->fill_lock = false; |
| 768 | INIT_LIST_HEAD(&pool->list); |
| 769 | pool->npages = pool->nfrees = 0; |
| 770 | pool->gfp_flags = flags; |
| 771 | pool->name = name; |
| 772 | } |
| 773 | |
| 774 | int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) |
| 775 | { |
| 776 | int ret; |
| 777 | if (atomic_add_return(1, &_manager.page_alloc_inited) > 1) |
| 778 | return 0; |
| 779 | |
| 780 | printk(KERN_INFO "[ttm] Initializing pool allocator.\n"); |
| 781 | |
| 782 | ttm_page_pool_init_locked(&_manager.wc_pool, GFP_HIGHUSER, "wc"); |
| 783 | |
| 784 | ttm_page_pool_init_locked(&_manager.uc_pool, GFP_HIGHUSER, "uc"); |
| 785 | |
| 786 | ttm_page_pool_init_locked(&_manager.wc_pool_dma32, GFP_USER | GFP_DMA32, |
| 787 | "wc dma"); |
| 788 | |
| 789 | ttm_page_pool_init_locked(&_manager.uc_pool_dma32, GFP_USER | GFP_DMA32, |
| 790 | "uc dma"); |
| 791 | |
| 792 | _manager.options.max_size = max_pages; |
| 793 | _manager.options.small = SMALL_ALLOCATION; |
| 794 | _manager.options.alloc_size = NUM_PAGES_TO_ALLOC; |
| 795 | |
| 796 | kobject_init(&_manager.kobj, &ttm_pool_kobj_type); |
| 797 | ret = kobject_add(&_manager.kobj, &glob->kobj, "pool"); |
| 798 | if (unlikely(ret != 0)) { |
| 799 | kobject_put(&_manager.kobj); |
| 800 | return ret; |
| 801 | } |
| 802 | |
| 803 | ttm_pool_mm_shrink_init(&_manager); |
| 804 | |
| 805 | return 0; |
| 806 | } |
| 807 | |
| 808 | void ttm_page_alloc_fini() |
| 809 | { |
| 810 | int i; |
| 811 | |
| 812 | if (atomic_sub_return(1, &_manager.page_alloc_inited) > 0) |
| 813 | return; |
| 814 | |
| 815 | printk(KERN_INFO "[ttm] Finilizing pool allocator.\n"); |
| 816 | ttm_pool_mm_shrink_fini(&_manager); |
| 817 | |
| 818 | for (i = 0; i < NUM_POOLS; ++i) |
| 819 | ttm_page_pool_free(&_manager.pools[i], FREE_ALL_PAGES); |
| 820 | |
| 821 | kobject_put(&_manager.kobj); |
| 822 | } |
| 823 | |
| 824 | int ttm_page_alloc_debugfs(struct seq_file *m, void *data) |
| 825 | { |
| 826 | struct ttm_page_pool *p; |
| 827 | unsigned i; |
| 828 | char *h[] = {"pool", "refills", "pages freed", "size"}; |
| 829 | if (atomic_read(&_manager.page_alloc_inited) == 0) { |
| 830 | seq_printf(m, "No pool allocator running.\n"); |
| 831 | return 0; |
| 832 | } |
| 833 | seq_printf(m, "%6s %12s %13s %8s\n", |
| 834 | h[0], h[1], h[2], h[3]); |
| 835 | for (i = 0; i < NUM_POOLS; ++i) { |
| 836 | p = &_manager.pools[i]; |
| 837 | |
| 838 | seq_printf(m, "%6s %12ld %13ld %8d\n", |
| 839 | p->name, p->nrefills, |
| 840 | p->nfrees, p->npages); |
| 841 | } |
| 842 | return 0; |
| 843 | } |
| 844 | EXPORT_SYMBOL(ttm_page_alloc_debugfs); |