1/* 2 * Copyright 2011 (c) Oracle Corp. 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 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 24 */ 25 26/* 27 * A simple DMA pool losely based on dmapool.c. It has certain advantages 28 * over the DMA pools: 29 * - Pool collects resently freed pages for reuse (and hooks up to 30 * the shrinker). 31 * - Tracks currently in use pages 32 * - Tracks whether the page is UC, WB or cached (and reverts to WB 33 * when freed). 34 */ 35 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD$"); 38 39#define pr_fmt(fmt) "[TTM] " fmt 40 41#include <linux/dma-mapping.h> 42#include <linux/list.h> 43#include <linux/seq_file.h> /* for seq_printf */ 44#include <linux/slab.h> 45#include <linux/spinlock.h> 46#include <linux/highmem.h> 47#include <linux/mm_types.h> 48#include <linux/module.h> 49#include <linux/mm.h> 50#include <linux/atomic.h> 51#include <linux/device.h> 52#include <linux/kthread.h> 53#include <drm/ttm/ttm_bo_driver.h> 54#include <drm/ttm/ttm_page_alloc.h> 55#ifdef TTM_HAS_AGP 56#include <asm/agp.h> 57#endif 58 59#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *)) 60#define SMALL_ALLOCATION 4 61#define FREE_ALL_PAGES (~0U) 62/* times are in msecs */ 63#define IS_UNDEFINED (0) 64#define IS_WC (1<<1) 65#define IS_UC (1<<2) 66#define IS_CACHED (1<<3) 67#define IS_DMA32 (1<<4) 68 69enum pool_type { 70 POOL_IS_UNDEFINED, 71 POOL_IS_WC = IS_WC, 72 POOL_IS_UC = IS_UC, 73 POOL_IS_CACHED = IS_CACHED, 74 POOL_IS_WC_DMA32 = IS_WC | IS_DMA32, 75 POOL_IS_UC_DMA32 = IS_UC | IS_DMA32, 76 POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32, 77}; 78/* 79 * The pool structure. There are usually six pools: 80 * - generic (not restricted to DMA32): 81 * - write combined, uncached, cached. 82 * - dma32 (up to 2^32 - so up 4GB): 83 * - write combined, uncached, cached. 84 * for each 'struct device'. The 'cached' is for pages that are actively used. 85 * The other ones can be shrunk by the shrinker API if neccessary. 86 * @pools: The 'struct device->dma_pools' link. 87 * @type: Type of the pool 88 * @lock: Protects the inuse_list and free_list from concurrnet access. Must be 89 * used with irqsave/irqrestore variants because pool allocator maybe called 90 * from delayed work. 91 * @inuse_list: Pool of pages that are in use. The order is very important and 92 * it is in the order that the TTM pages that are put back are in. 93 * @free_list: Pool of pages that are free to be used. No order requirements. 94 * @dev: The device that is associated with these pools. 95 * @size: Size used during DMA allocation. 96 * @npages_free: Count of available pages for re-use. 97 * @npages_in_use: Count of pages that are in use. 98 * @nfrees: Stats when pool is shrinking. 99 * @nrefills: Stats when the pool is grown. 100 * @gfp_flags: Flags to pass for alloc_page. 101 * @name: Name of the pool. 102 * @dev_name: Name derieved from dev - similar to how dev_info works. 103 * Used during shutdown as the dev_info during release is unavailable. 104 */ 105struct dma_pool { 106 struct list_head pools; /* The 'struct device->dma_pools link */ 107 enum pool_type type; 108 spinlock_t lock; 109 struct list_head inuse_list; 110 struct list_head free_list; 111 struct device *dev; 112 unsigned size; 113 unsigned npages_free; 114 unsigned npages_in_use; 115 unsigned long nfrees; /* Stats when shrunk. */ 116 unsigned long nrefills; /* Stats when grown. */ 117 gfp_t gfp_flags; 118 char name[13]; /* "cached dma32" */ 119 char dev_name[64]; /* Constructed from dev */ 120}; 121 122/* 123 * The accounting page keeping track of the allocated page along with 124 * the DMA address. 125 * @page_list: The link to the 'page_list' in 'struct dma_pool'. 126 * @vaddr: The virtual address of the page 127 * @dma: The bus address of the page. If the page is not allocated 128 * via the DMA API, it will be -1. 129 */ 130struct dma_page { 131 struct list_head page_list; 132 void *vaddr; 133 struct page *p; 134 dma_addr_t dma; 135}; 136 137/* 138 * Limits for the pool. They are handled without locks because only place where 139 * they may change is in sysfs store. They won't have immediate effect anyway 140 * so forcing serialization to access them is pointless. 141 */ 142 143struct ttm_pool_opts { 144 unsigned alloc_size; 145 unsigned max_size; 146 unsigned small; 147}; 148 149/* 150 * Contains the list of all of the 'struct device' and their corresponding 151 * DMA pools. Guarded by _mutex->lock. 152 * @pools: The link to 'struct ttm_pool_manager->pools' 153 * @dev: The 'struct device' associated with the 'pool' 154 * @pool: The 'struct dma_pool' associated with the 'dev' 155 */ 156struct device_pools { 157 struct list_head pools; 158 struct device *dev; 159 struct dma_pool *pool; 160}; 161 162/* 163 * struct ttm_pool_manager - Holds memory pools for fast allocation 164 * 165 * @lock: Lock used when adding/removing from pools 166 * @pools: List of 'struct device' and 'struct dma_pool' tuples. 167 * @options: Limits for the pool. 168 * @npools: Total amount of pools in existence. 169 * @shrinker: The structure used by [un|]register_shrinker 170 */ 171struct ttm_pool_manager { 172 struct mutex lock; 173 struct list_head pools; 174 struct ttm_pool_opts options; 175 unsigned npools; 176 struct shrinker mm_shrink; 177 struct kobject kobj; 178}; 179 180static struct ttm_pool_manager *_manager; 181 182static struct attribute ttm_page_pool_max = { 183 .name = "pool_max_size", 184 .mode = S_IRUGO | S_IWUSR 185}; 186static struct attribute ttm_page_pool_small = { 187 .name = "pool_small_allocation", 188 .mode = S_IRUGO | S_IWUSR 189}; 190static struct attribute ttm_page_pool_alloc_size = { 191 .name = "pool_allocation_size", 192 .mode = S_IRUGO | S_IWUSR 193}; 194 195static struct attribute *ttm_pool_attrs[] = { 196 &ttm_page_pool_max, 197 &ttm_page_pool_small, 198 &ttm_page_pool_alloc_size, 199 NULL 200}; 201 202static void ttm_pool_kobj_release(struct kobject *kobj) 203{ 204 struct ttm_pool_manager *m = 205 container_of(kobj, struct ttm_pool_manager, kobj); 206 kfree(m); 207} 208 209static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr, 210 const char *buffer, size_t size) 211{ 212 struct ttm_pool_manager *m = 213 container_of(kobj, struct ttm_pool_manager, kobj); 214 int chars; 215 unsigned val; 216 chars = sscanf(buffer, "%u", &val); 217 if (chars == 0) 218 return size; 219 220 /* Convert kb to number of pages */ 221 val = val / (PAGE_SIZE >> 10); 222 223 if (attr == &ttm_page_pool_max) 224 m->options.max_size = val; 225 else if (attr == &ttm_page_pool_small) 226 m->options.small = val; 227 else if (attr == &ttm_page_pool_alloc_size) { 228 if (val > NUM_PAGES_TO_ALLOC*8) { 229 pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n", 230 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7), 231 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); 232 return size; 233 } else if (val > NUM_PAGES_TO_ALLOC) { 234 pr_warn("Setting allocation size to larger than %lu is not recommended\n", 235 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); 236 } 237 m->options.alloc_size = val; 238 } 239 240 return size; 241} 242 243static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr, 244 char *buffer) 245{ 246 struct ttm_pool_manager *m = 247 container_of(kobj, struct ttm_pool_manager, kobj); 248 unsigned val = 0; 249 250 if (attr == &ttm_page_pool_max) 251 val = m->options.max_size; 252 else if (attr == &ttm_page_pool_small) 253 val = m->options.small; 254 else if (attr == &ttm_page_pool_alloc_size) 255 val = m->options.alloc_size; 256 257 val = val * (PAGE_SIZE >> 10); 258 259 return snprintf(buffer, PAGE_SIZE, "%u\n", val); 260} 261 262static const struct sysfs_ops ttm_pool_sysfs_ops = { 263 .show = &ttm_pool_show, 264 .store = &ttm_pool_store, 265}; 266 267static struct kobj_type ttm_pool_kobj_type = { 268 .release = &ttm_pool_kobj_release, 269 .sysfs_ops = &ttm_pool_sysfs_ops, 270 .default_attrs = ttm_pool_attrs, 271}; 272 273#ifndef CONFIG_X86 274static int set_pages_array_wb(struct page **pages, int addrinarray) 275{ 276#ifdef TTM_HAS_AGP 277 int i; 278 279 for (i = 0; i < addrinarray; i++) 280 unmap_page_from_agp(pages[i]); 281#endif 282 return 0; 283} 284 285static int set_pages_array_wc(struct page **pages, int addrinarray) 286{ 287#ifdef TTM_HAS_AGP 288 int i; 289 290 for (i = 0; i < addrinarray; i++) 291 map_page_into_agp(pages[i]); 292#endif 293 return 0; 294} 295 296static int set_pages_array_uc(struct page **pages, int addrinarray) 297{ 298#ifdef TTM_HAS_AGP 299 int i; 300 301 for (i = 0; i < addrinarray; i++) 302 map_page_into_agp(pages[i]); 303#endif 304 return 0; 305} 306#endif /* for !CONFIG_X86 */ 307 308static int ttm_set_pages_caching(struct dma_pool *pool, 309 struct page **pages, unsigned cpages) 310{ 311 int r = 0; 312 /* Set page caching */ 313 if (pool->type & IS_UC) { 314 r = set_pages_array_uc(pages, cpages); 315 if (r) 316 pr_err("%s: Failed to set %d pages to uc!\n", 317 pool->dev_name, cpages); 318 } 319 if (pool->type & IS_WC) { 320 r = set_pages_array_wc(pages, cpages); 321 if (r) 322 pr_err("%s: Failed to set %d pages to wc!\n", 323 pool->dev_name, cpages); 324 } 325 return r; 326} 327 328static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page) 329{ 330 dma_addr_t dma = d_page->dma; 331 dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma); 332 333 kfree(d_page); 334 d_page = NULL; 335} 336static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool) 337{ 338 struct dma_page *d_page; 339 340 d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL); 341 if (!d_page) 342 return NULL; 343 344 d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size, 345 &d_page->dma, 346 pool->gfp_flags); 347 if (d_page->vaddr) 348 d_page->p = virt_to_page(d_page->vaddr); 349 else { 350 kfree(d_page); 351 d_page = NULL; 352 } 353 return d_page; 354} 355static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate) 356{ 357 enum pool_type type = IS_UNDEFINED; 358 359 if (flags & TTM_PAGE_FLAG_DMA32) 360 type |= IS_DMA32; 361 if (cstate == tt_cached) 362 type |= IS_CACHED; 363 else if (cstate == tt_uncached) 364 type |= IS_UC; 365 else 366 type |= IS_WC; 367 368 return type; 369} 370 371static void ttm_pool_update_free_locked(struct dma_pool *pool, 372 unsigned freed_pages) 373{ 374 pool->npages_free -= freed_pages; 375 pool->nfrees += freed_pages; 376 377} 378 379/* set memory back to wb and free the pages. */ 380static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages, 381 struct page *pages[], unsigned npages) 382{ 383 struct dma_page *d_page, *tmp; 384 385 /* Don't set WB on WB page pool. */ 386 if (npages && !(pool->type & IS_CACHED) && 387 set_pages_array_wb(pages, npages)) 388 pr_err("%s: Failed to set %d pages to wb!\n", 389 pool->dev_name, npages); 390 391 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { 392 list_del(&d_page->page_list); 393 __ttm_dma_free_page(pool, d_page); 394 } 395} 396 397static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page) 398{ 399 /* Don't set WB on WB page pool. */ 400 if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1)) 401 pr_err("%s: Failed to set %d pages to wb!\n", 402 pool->dev_name, 1); 403 404 list_del(&d_page->page_list); 405 __ttm_dma_free_page(pool, d_page); 406} 407 408/* 409 * Free pages from pool. 410 * 411 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC 412 * number of pages in one go. 413 * 414 * @pool: to free the pages from 415 * @nr_free: If set to true will free all pages in pool 416 **/ 417static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free) 418{ 419 unsigned long irq_flags; 420 struct dma_page *dma_p, *tmp; 421 struct page **pages_to_free; 422 struct list_head d_pages; 423 unsigned freed_pages = 0, 424 npages_to_free = nr_free; 425 426 if (NUM_PAGES_TO_ALLOC < nr_free) 427 npages_to_free = NUM_PAGES_TO_ALLOC; 428#if 0 429 if (nr_free > 1) { 430 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n", 431 pool->dev_name, pool->name, current->pid, 432 npages_to_free, nr_free); 433 } 434#endif 435 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), 436 GFP_KERNEL); 437 438 if (!pages_to_free) { 439 pr_err("%s: Failed to allocate memory for pool free operation\n", 440 pool->dev_name); 441 return 0; 442 } 443 INIT_LIST_HEAD(&d_pages); 444restart: 445 spin_lock_irqsave(&pool->lock, irq_flags); 446 447 /* We picking the oldest ones off the list */ 448 list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list, 449 page_list) { 450 if (freed_pages >= npages_to_free) 451 break; 452 453 /* Move the dma_page from one list to another. */ 454 list_move(&dma_p->page_list, &d_pages); 455 456 pages_to_free[freed_pages++] = dma_p->p; 457 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */ 458 if (freed_pages >= NUM_PAGES_TO_ALLOC) { 459 460 ttm_pool_update_free_locked(pool, freed_pages); 461 /** 462 * Because changing page caching is costly 463 * we unlock the pool to prevent stalling. 464 */ 465 spin_unlock_irqrestore(&pool->lock, irq_flags); 466 467 ttm_dma_pages_put(pool, &d_pages, pages_to_free, 468 freed_pages); 469 470 INIT_LIST_HEAD(&d_pages); 471 472 if (likely(nr_free != FREE_ALL_PAGES)) 473 nr_free -= freed_pages; 474 475 if (NUM_PAGES_TO_ALLOC >= nr_free) 476 npages_to_free = nr_free; 477 else 478 npages_to_free = NUM_PAGES_TO_ALLOC; 479 480 freed_pages = 0; 481 482 /* free all so restart the processing */ 483 if (nr_free) 484 goto restart; 485 486 /* Not allowed to fall through or break because 487 * following context is inside spinlock while we are 488 * outside here. 489 */ 490 goto out; 491 492 } 493 } 494 495 /* remove range of pages from the pool */ 496 if (freed_pages) { 497 ttm_pool_update_free_locked(pool, freed_pages); 498 nr_free -= freed_pages; 499 } 500 501 spin_unlock_irqrestore(&pool->lock, irq_flags); 502 503 if (freed_pages) 504 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages); 505out: 506 kfree(pages_to_free); 507 return nr_free; 508} 509 510static void ttm_dma_free_pool(struct device *dev, enum pool_type type) 511{ 512 struct device_pools *p; 513 struct dma_pool *pool; 514 515 if (!dev) 516 return; 517 518 mutex_lock(&_manager->lock); 519 list_for_each_entry_reverse(p, &_manager->pools, pools) { 520 if (p->dev != dev) 521 continue; 522 pool = p->pool; 523 if (pool->type != type) 524 continue; 525 526 list_del(&p->pools); 527 kfree(p); 528 _manager->npools--; 529 break; 530 } 531 list_for_each_entry_reverse(pool, &dev->dma_pools, pools) { 532 if (pool->type != type) 533 continue; 534 /* Takes a spinlock.. */ 535 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES); 536 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0)); 537 /* This code path is called after _all_ references to the 538 * struct device has been dropped - so nobody should be 539 * touching it. In case somebody is trying to _add_ we are 540 * guarded by the mutex. */ 541 list_del(&pool->pools); 542 kfree(pool); 543 break; 544 } 545 mutex_unlock(&_manager->lock); 546} 547 548/* 549 * On free-ing of the 'struct device' this deconstructor is run. 550 * Albeit the pool might have already been freed earlier. 551 */ 552static void ttm_dma_pool_release(struct device *dev, void *res) 553{ 554 struct dma_pool *pool = *(struct dma_pool **)res; 555 556 if (pool) 557 ttm_dma_free_pool(dev, pool->type); 558} 559 560static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data) 561{ 562 return *(struct dma_pool **)res == match_data; 563} 564 565static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags, 566 enum pool_type type) 567{ 568 char *n[] = {"wc", "uc", "cached", " dma32", "unknown",}; 569 enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED}; 570 struct device_pools *sec_pool = NULL; 571 struct dma_pool *pool = NULL, **ptr; 572 unsigned i; 573 int ret = -ENODEV; 574 char *p; 575 576 if (!dev) 577 return NULL; 578 579 ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL); 580 if (!ptr) 581 return NULL; 582 583 ret = -ENOMEM; 584 585 pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL, 586 dev_to_node(dev)); 587 if (!pool) 588 goto err_mem; 589 590 sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL, 591 dev_to_node(dev)); 592 if (!sec_pool) 593 goto err_mem; 594 595 INIT_LIST_HEAD(&sec_pool->pools); 596 sec_pool->dev = dev; 597 sec_pool->pool = pool; 598 599 INIT_LIST_HEAD(&pool->free_list); 600 INIT_LIST_HEAD(&pool->inuse_list); 601 INIT_LIST_HEAD(&pool->pools); 602 spin_lock_init(&pool->lock); 603 pool->dev = dev; 604 pool->npages_free = pool->npages_in_use = 0; 605 pool->nfrees = 0; 606 pool->gfp_flags = flags; 607 pool->size = PAGE_SIZE; 608 pool->type = type; 609 pool->nrefills = 0; 610 p = pool->name; 611 for (i = 0; i < 5; i++) { 612 if (type & t[i]) { 613 p += snprintf(p, sizeof(pool->name) - (p - pool->name), 614 "%s", n[i]); 615 } 616 } 617 *p = 0; 618 /* We copy the name for pr_ calls b/c when dma_pool_destroy is called 619 * - the kobj->name has already been deallocated.*/ 620 snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s", 621 dev_driver_string(dev), dev_name(dev)); 622 mutex_lock(&_manager->lock); 623 /* You can get the dma_pool from either the global: */ 624 list_add(&sec_pool->pools, &_manager->pools); 625 _manager->npools++; 626 /* or from 'struct device': */ 627 list_add(&pool->pools, &dev->dma_pools); 628 mutex_unlock(&_manager->lock); 629 630 *ptr = pool; 631 devres_add(dev, ptr); 632 633 return pool; 634err_mem: 635 devres_free(ptr); 636 kfree(sec_pool); 637 kfree(pool); 638 return ERR_PTR(ret); 639} 640 641static struct dma_pool *ttm_dma_find_pool(struct device *dev, 642 enum pool_type type) 643{ 644 struct dma_pool *pool, *tmp, *found = NULL; 645 646 if (type == IS_UNDEFINED) 647 return found; 648 649 /* NB: We iterate on the 'struct dev' which has no spinlock, but 650 * it does have a kref which we have taken. The kref is taken during 651 * graphic driver loading - in the drm_pci_init it calls either 652 * pci_dev_get or pci_register_driver which both end up taking a kref 653 * on 'struct device'. 654 * 655 * On teardown, the graphic drivers end up quiescing the TTM (put_pages) 656 * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice 657 * thing is at that point of time there are no pages associated with the 658 * driver so this function will not be called. 659 */ 660 list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) { 661 if (pool->type != type) 662 continue; 663 found = pool; 664 break; 665 } 666 return found; 667} 668 669/* 670 * Free pages the pages that failed to change the caching state. If there 671 * are pages that have changed their caching state already put them to the 672 * pool. 673 */ 674static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool, 675 struct list_head *d_pages, 676 struct page **failed_pages, 677 unsigned cpages) 678{ 679 struct dma_page *d_page, *tmp; 680 struct page *p; 681 unsigned i = 0; 682 683 p = failed_pages[0]; 684 if (!p) 685 return; 686 /* Find the failed page. */ 687 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { 688 if (d_page->p != p) 689 continue; 690 /* .. and then progress over the full list. */ 691 list_del(&d_page->page_list); 692 __ttm_dma_free_page(pool, d_page); 693 if (++i < cpages) 694 p = failed_pages[i]; 695 else 696 break; 697 } 698 699} 700 701/* 702 * Allocate 'count' pages, and put 'need' number of them on the 703 * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset. 704 * The full list of pages should also be on 'd_pages'. 705 * We return zero for success, and negative numbers as errors. 706 */ 707static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool, 708 struct list_head *d_pages, 709 unsigned count) 710{ 711 struct page **caching_array; 712 struct dma_page *dma_p; 713 struct page *p; 714 int r = 0; 715 unsigned i, cpages; 716 unsigned max_cpages = min(count, 717 (unsigned)(PAGE_SIZE/sizeof(struct page *))); 718 719 /* allocate array for page caching change */ 720 caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL); 721 722 if (!caching_array) { 723 pr_err("%s: Unable to allocate table for new pages\n", 724 pool->dev_name); 725 return -ENOMEM; 726 } 727 728 if (count > 1) { 729 pr_debug("%s: (%s:%d) Getting %d pages\n", 730 pool->dev_name, pool->name, current->pid, count); 731 } 732 733 for (i = 0, cpages = 0; i < count; ++i) { 734 dma_p = __ttm_dma_alloc_page(pool); 735 if (!dma_p) { 736 pr_err("%s: Unable to get page %u\n", 737 pool->dev_name, i); 738 739 /* store already allocated pages in the pool after 740 * setting the caching state */ 741 if (cpages) { 742 r = ttm_set_pages_caching(pool, caching_array, 743 cpages); 744 if (r) 745 ttm_dma_handle_caching_state_failure( 746 pool, d_pages, caching_array, 747 cpages); 748 } 749 r = -ENOMEM; 750 goto out; 751 } 752 p = dma_p->p; 753#ifdef CONFIG_HIGHMEM 754 /* gfp flags of highmem page should never be dma32 so we 755 * we should be fine in such case 756 */ 757 if (!PageHighMem(p)) 758#endif 759 { 760 caching_array[cpages++] = p; 761 if (cpages == max_cpages) { 762 /* Note: Cannot hold the spinlock */ 763 r = ttm_set_pages_caching(pool, caching_array, 764 cpages); 765 if (r) { 766 ttm_dma_handle_caching_state_failure( 767 pool, d_pages, caching_array, 768 cpages); 769 goto out; 770 } 771 cpages = 0; 772 } 773 } 774 list_add(&dma_p->page_list, d_pages); 775 } 776 777 if (cpages) { 778 r = ttm_set_pages_caching(pool, caching_array, cpages); 779 if (r) 780 ttm_dma_handle_caching_state_failure(pool, d_pages, 781 caching_array, cpages); 782 } 783out: 784 kfree(caching_array); 785 return r; 786} 787 788/* 789 * @return count of pages still required to fulfill the request. 790 */ 791static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool, 792 unsigned long *irq_flags) 793{ 794 unsigned count = _manager->options.small; 795 int r = pool->npages_free; 796 797 if (count > pool->npages_free) { 798 struct list_head d_pages; 799 800 INIT_LIST_HEAD(&d_pages); 801 802 spin_unlock_irqrestore(&pool->lock, *irq_flags); 803 804 /* Returns how many more are neccessary to fulfill the 805 * request. */ 806 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count); 807 808 spin_lock_irqsave(&pool->lock, *irq_flags); 809 if (!r) { 810 /* Add the fresh to the end.. */ 811 list_splice(&d_pages, &pool->free_list); 812 ++pool->nrefills; 813 pool->npages_free += count; 814 r = count; 815 } else { 816 struct dma_page *d_page; 817 unsigned cpages = 0; 818 819 pr_err("%s: Failed to fill %s pool (r:%d)!\n", 820 pool->dev_name, pool->name, r); 821 822 list_for_each_entry(d_page, &d_pages, page_list) { 823 cpages++; 824 } 825 list_splice_tail(&d_pages, &pool->free_list); 826 pool->npages_free += cpages; 827 r = cpages; 828 } 829 } 830 return r; 831} 832 833/* 834 * @return count of pages still required to fulfill the request. 835 * The populate list is actually a stack (not that is matters as TTM 836 * allocates one page at a time. 837 */ 838static int ttm_dma_pool_get_pages(struct dma_pool *pool, 839 struct ttm_dma_tt *ttm_dma, 840 unsigned index) 841{ 842 struct dma_page *d_page; 843 struct ttm_tt *ttm = &ttm_dma->ttm; 844 unsigned long irq_flags; 845 int count, r = -ENOMEM; 846 847 spin_lock_irqsave(&pool->lock, irq_flags); 848 count = ttm_dma_page_pool_fill_locked(pool, &irq_flags); 849 if (count) { 850 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list); 851 ttm->pages[index] = d_page->p; 852 ttm_dma->dma_address[index] = d_page->dma; 853 list_move_tail(&d_page->page_list, &ttm_dma->pages_list); 854 r = 0; 855 pool->npages_in_use += 1; 856 pool->npages_free -= 1; 857 } 858 spin_unlock_irqrestore(&pool->lock, irq_flags); 859 return r; 860} 861 862/* 863 * On success pages list will hold count number of correctly 864 * cached pages. On failure will hold the negative return value (-ENOMEM, etc). 865 */ 866int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev) 867{ 868 struct ttm_tt *ttm = &ttm_dma->ttm; 869 struct ttm_mem_global *mem_glob = ttm->glob->mem_glob; 870 struct dma_pool *pool; 871 enum pool_type type; 872 unsigned i; 873 gfp_t gfp_flags; 874 int ret; 875 876 if (ttm->state != tt_unpopulated) 877 return 0; 878 879 type = ttm_to_type(ttm->page_flags, ttm->caching_state); 880 if (ttm->page_flags & TTM_PAGE_FLAG_DMA32) 881 gfp_flags = GFP_USER | GFP_DMA32; 882 else 883 gfp_flags = GFP_HIGHUSER; 884 if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC) 885 gfp_flags |= __GFP_ZERO; 886 887 pool = ttm_dma_find_pool(dev, type); 888 if (!pool) { 889 pool = ttm_dma_pool_init(dev, gfp_flags, type); 890 if (IS_ERR_OR_NULL(pool)) { 891 return -ENOMEM; 892 } 893 } 894 895 INIT_LIST_HEAD(&ttm_dma->pages_list); 896 for (i = 0; i < ttm->num_pages; ++i) { 897 ret = ttm_dma_pool_get_pages(pool, ttm_dma, i); 898 if (ret != 0) { 899 ttm_dma_unpopulate(ttm_dma, dev); 900 return -ENOMEM; 901 } 902 903 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i], 904 false, false); 905 if (unlikely(ret != 0)) { 906 ttm_dma_unpopulate(ttm_dma, dev); 907 return -ENOMEM; 908 } 909 } 910 911 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) { 912 ret = ttm_tt_swapin(ttm); 913 if (unlikely(ret != 0)) { 914 ttm_dma_unpopulate(ttm_dma, dev); 915 return ret; 916 } 917 } 918 919 ttm->state = tt_unbound; 920 return 0; 921} 922EXPORT_SYMBOL_GPL(ttm_dma_populate); 923 924/* Get good estimation how many pages are free in pools */ 925static int ttm_dma_pool_get_num_unused_pages(void) 926{ 927 struct device_pools *p; 928 unsigned total = 0; 929 930 mutex_lock(&_manager->lock); 931 list_for_each_entry(p, &_manager->pools, pools) 932 total += p->pool->npages_free; 933 mutex_unlock(&_manager->lock); 934 return total; 935} 936 937/* Put all pages in pages list to correct pool to wait for reuse */ 938void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) 939{ 940 struct ttm_tt *ttm = &ttm_dma->ttm; 941 struct dma_pool *pool; 942 struct dma_page *d_page, *next; 943 enum pool_type type; 944 bool is_cached = false; 945 unsigned count = 0, i, npages = 0; 946 unsigned long irq_flags; 947 948 type = ttm_to_type(ttm->page_flags, ttm->caching_state); 949 pool = ttm_dma_find_pool(dev, type); 950 if (!pool) 951 return; 952 953 is_cached = (ttm_dma_find_pool(pool->dev, 954 ttm_to_type(ttm->page_flags, tt_cached)) == pool); 955 956 /* make sure pages array match list and count number of pages */ 957 list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) { 958 ttm->pages[count] = d_page->p; 959 count++; 960 } 961 962 spin_lock_irqsave(&pool->lock, irq_flags); 963 pool->npages_in_use -= count; 964 if (is_cached) { 965 pool->nfrees += count; 966 } else { 967 pool->npages_free += count; 968 list_splice(&ttm_dma->pages_list, &pool->free_list); 969 npages = count; 970 if (pool->npages_free > _manager->options.max_size) { 971 npages = pool->npages_free - _manager->options.max_size; 972 /* free at least NUM_PAGES_TO_ALLOC number of pages 973 * to reduce calls to set_memory_wb */ 974 if (npages < NUM_PAGES_TO_ALLOC) 975 npages = NUM_PAGES_TO_ALLOC; 976 } 977 } 978 spin_unlock_irqrestore(&pool->lock, irq_flags); 979 980 if (is_cached) { 981 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) { 982 ttm_mem_global_free_page(ttm->glob->mem_glob, 983 d_page->p); 984 ttm_dma_page_put(pool, d_page); 985 } 986 } else { 987 for (i = 0; i < count; i++) { 988 ttm_mem_global_free_page(ttm->glob->mem_glob, 989 ttm->pages[i]); 990 } 991 } 992 993 INIT_LIST_HEAD(&ttm_dma->pages_list); 994 for (i = 0; i < ttm->num_pages; i++) { 995 ttm->pages[i] = NULL; 996 ttm_dma->dma_address[i] = 0; 997 } 998 999 /* shrink pool if necessary (only on !is_cached pools)*/ 1000 if (npages) 1001 ttm_dma_page_pool_free(pool, npages); 1002 ttm->state = tt_unpopulated; 1003} 1004EXPORT_SYMBOL_GPL(ttm_dma_unpopulate); 1005 1006/** 1007 * Callback for mm to request pool to reduce number of page held. 1008 */ 1009static int ttm_dma_pool_mm_shrink(struct shrinker *shrink, 1010 struct shrink_control *sc) 1011{ 1012 static atomic_t start_pool = ATOMIC_INIT(0); 1013 unsigned idx = 0; 1014 unsigned pool_offset = atomic_add_return(1, &start_pool); 1015 unsigned shrink_pages = sc->nr_to_scan; 1016 struct device_pools *p; 1017 1018 if (list_empty(&_manager->pools)) 1019 return 0; 1020 1021 mutex_lock(&_manager->lock); 1022 pool_offset = pool_offset % _manager->npools; 1023 list_for_each_entry(p, &_manager->pools, pools) { 1024 unsigned nr_free; 1025 1026 if (!p->dev) 1027 continue; 1028 if (shrink_pages == 0) 1029 break; 1030 /* Do it in round-robin fashion. */ 1031 if (++idx < pool_offset) 1032 continue; 1033 nr_free = shrink_pages; 1034 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free); 1035 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n", 1036 p->pool->dev_name, p->pool->name, current->pid, 1037 nr_free, shrink_pages); 1038 } 1039 mutex_unlock(&_manager->lock); 1040 /* return estimated number of unused pages in pool */ 1041 return ttm_dma_pool_get_num_unused_pages(); 1042} 1043 1044static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager) 1045{ 1046 manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink; 1047 manager->mm_shrink.seeks = 1; 1048 register_shrinker(&manager->mm_shrink); 1049} 1050 1051static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager) 1052{ 1053 unregister_shrinker(&manager->mm_shrink); 1054} 1055 1056int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) 1057{ 1058 int ret = -ENOMEM; 1059 1060 WARN_ON(_manager); 1061 1062 pr_info("Initializing DMA pool allocator\n"); 1063 1064 _manager = kzalloc(sizeof(*_manager), GFP_KERNEL); 1065 if (!_manager) 1066 goto err; 1067 1068 mutex_init(&_manager->lock); 1069 INIT_LIST_HEAD(&_manager->pools); 1070 1071 _manager->options.max_size = max_pages; 1072 _manager->options.small = SMALL_ALLOCATION; 1073 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC; 1074 1075 /* This takes care of auto-freeing the _manager */ 1076 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type, 1077 &glob->kobj, "dma_pool"); 1078 if (unlikely(ret != 0)) { 1079 kobject_put(&_manager->kobj); 1080 goto err; 1081 } 1082 ttm_dma_pool_mm_shrink_init(_manager); 1083 return 0; 1084err: 1085 return ret; 1086} 1087 1088void ttm_dma_page_alloc_fini(void) 1089{ 1090 struct device_pools *p, *t; 1091 1092 pr_info("Finalizing DMA pool allocator\n"); 1093 ttm_dma_pool_mm_shrink_fini(_manager); 1094 1095 list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) { 1096 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name, 1097 current->pid); 1098 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release, 1099 ttm_dma_pool_match, p->pool)); 1100 ttm_dma_free_pool(p->dev, p->pool->type); 1101 } 1102 kobject_put(&_manager->kobj); 1103 _manager = NULL; 1104} 1105 1106int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data) 1107{ 1108 struct device_pools *p; 1109 struct dma_pool *pool = NULL; 1110 char *h[] = {"pool", "refills", "pages freed", "inuse", "available", 1111 "name", "virt", "busaddr"}; 1112 1113 if (!_manager) { 1114 seq_printf(m, "No pool allocator running.\n"); 1115 return 0; 1116 } 1117 seq_printf(m, "%13s %12s %13s %8s %8s %8s\n", 1118 h[0], h[1], h[2], h[3], h[4], h[5]); 1119 mutex_lock(&_manager->lock); 1120 list_for_each_entry(p, &_manager->pools, pools) { 1121 struct device *dev = p->dev; 1122 if (!dev) 1123 continue; 1124 pool = p->pool; 1125 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n", 1126 pool->name, pool->nrefills, 1127 pool->nfrees, pool->npages_in_use, 1128 pool->npages_free, 1129 pool->dev_name); 1130 } 1131 mutex_unlock(&_manager->lock); 1132 return 0; 1133} 1134EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs); 1135