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#if defined(CONFIG_SWIOTLB) || defined(CONFIG_INTEL_IOMMU) 37#define pr_fmt(fmt) "[TTM] " fmt 38 39#include <linux/dma-mapping.h> 40#include <linux/list.h> 41#include <linux/seq_file.h> /* for seq_printf */ 42#include <linux/slab.h> 43#include <linux/spinlock.h> 44#include <linux/highmem.h> 45#include <linux/mm_types.h> 46#include <linux/module.h> 47#include <linux/mm.h> 48#include <linux/atomic.h> 49#include <linux/device.h> 50#include <linux/kthread.h> 51#include <drm/ttm/ttm_bo_driver.h> 52#include <drm/ttm/ttm_page_alloc.h> 53#ifdef TTM_HAS_AGP 54#include <asm/agp.h> 55#endif 56 57#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *)) 58#define SMALL_ALLOCATION 4 59#define FREE_ALL_PAGES (~0U) 60/* times are in msecs */ 61#define IS_UNDEFINED (0) 62#define IS_WC (1<<1) 63#define IS_UC (1<<2) 64#define IS_CACHED (1<<3) 65#define IS_DMA32 (1<<4) 66 67enum pool_type { 68 POOL_IS_UNDEFINED, 69 POOL_IS_WC = IS_WC, 70 POOL_IS_UC = IS_UC, 71 POOL_IS_CACHED = IS_CACHED, 72 POOL_IS_WC_DMA32 = IS_WC | IS_DMA32, 73 POOL_IS_UC_DMA32 = IS_UC | IS_DMA32, 74 POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32, 75}; 76/* 77 * The pool structure. There are usually six pools: 78 * - generic (not restricted to DMA32): 79 * - write combined, uncached, cached. 80 * - dma32 (up to 2^32 - so up 4GB): 81 * - write combined, uncached, cached. 82 * for each 'struct device'. The 'cached' is for pages that are actively used. 83 * The other ones can be shrunk by the shrinker API if neccessary. 84 * @pools: The 'struct device->dma_pools' link. 85 * @type: Type of the pool 86 * @lock: Protects the inuse_list and free_list from concurrnet access. Must be 87 * used with irqsave/irqrestore variants because pool allocator maybe called 88 * from delayed work. 89 * @inuse_list: Pool of pages that are in use. The order is very important and 90 * it is in the order that the TTM pages that are put back are in. 91 * @free_list: Pool of pages that are free to be used. No order requirements. 92 * @dev: The device that is associated with these pools. 93 * @size: Size used during DMA allocation. 94 * @npages_free: Count of available pages for re-use. 95 * @npages_in_use: Count of pages that are in use. 96 * @nfrees: Stats when pool is shrinking. 97 * @nrefills: Stats when the pool is grown. 98 * @gfp_flags: Flags to pass for alloc_page. 99 * @name: Name of the pool. 100 * @dev_name: Name derieved from dev - similar to how dev_info works. 101 * Used during shutdown as the dev_info during release is unavailable. 102 */ 103struct dma_pool { 104 struct list_head pools; /* The 'struct device->dma_pools link */ 105 enum pool_type type; 106 spinlock_t lock; 107 struct list_head inuse_list; 108 struct list_head free_list; 109 struct device *dev; 110 unsigned size; 111 unsigned npages_free; 112 unsigned npages_in_use; 113 unsigned long nfrees; /* Stats when shrunk. */ 114 unsigned long nrefills; /* Stats when grown. */ 115 gfp_t gfp_flags; 116 char name[13]; /* "cached dma32" */ 117 char dev_name[64]; /* Constructed from dev */ 118}; 119 120/* 121 * The accounting page keeping track of the allocated page along with 122 * the DMA address. 123 * @page_list: The link to the 'page_list' in 'struct dma_pool'. 124 * @vaddr: The virtual address of the page 125 * @dma: The bus address of the page. If the page is not allocated 126 * via the DMA API, it will be -1. 127 */ 128struct dma_page { 129 struct list_head page_list; 130 void *vaddr; 131 struct page *p; 132 dma_addr_t dma; 133}; 134 135/* 136 * Limits for the pool. They are handled without locks because only place where 137 * they may change is in sysfs store. They won't have immediate effect anyway 138 * so forcing serialization to access them is pointless. 139 */ 140 141struct ttm_pool_opts { 142 unsigned alloc_size; 143 unsigned max_size; 144 unsigned small; 145}; 146 147/* 148 * Contains the list of all of the 'struct device' and their corresponding 149 * DMA pools. Guarded by _mutex->lock. 150 * @pools: The link to 'struct ttm_pool_manager->pools' 151 * @dev: The 'struct device' associated with the 'pool' 152 * @pool: The 'struct dma_pool' associated with the 'dev' 153 */ 154struct device_pools { 155 struct list_head pools; 156 struct device *dev; 157 struct dma_pool *pool; 158}; 159 160/* 161 * struct ttm_pool_manager - Holds memory pools for fast allocation 162 * 163 * @lock: Lock used when adding/removing from pools 164 * @pools: List of 'struct device' and 'struct dma_pool' tuples. 165 * @options: Limits for the pool. 166 * @npools: Total amount of pools in existence. 167 * @shrinker: The structure used by [un|]register_shrinker 168 */ 169struct ttm_pool_manager { 170 struct mutex lock; 171 struct list_head pools; 172 struct ttm_pool_opts options; 173 unsigned npools; 174 struct shrinker mm_shrink; 175 struct kobject kobj; 176}; 177 178static struct ttm_pool_manager *_manager; 179 180static struct attribute ttm_page_pool_max = { 181 .name = "pool_max_size", 182 .mode = S_IRUGO | S_IWUSR 183}; 184static struct attribute ttm_page_pool_small = { 185 .name = "pool_small_allocation", 186 .mode = S_IRUGO | S_IWUSR 187}; 188static struct attribute ttm_page_pool_alloc_size = { 189 .name = "pool_allocation_size", 190 .mode = S_IRUGO | S_IWUSR 191}; 192 193static struct attribute *ttm_pool_attrs[] = { 194 &ttm_page_pool_max, 195 &ttm_page_pool_small, 196 &ttm_page_pool_alloc_size, 197 NULL 198}; 199 200static void ttm_pool_kobj_release(struct kobject *kobj) 201{ 202 struct ttm_pool_manager *m = 203 container_of(kobj, struct ttm_pool_manager, kobj); 204 kfree(m); 205} 206 207static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr, 208 const char *buffer, size_t size) 209{ 210 struct ttm_pool_manager *m = 211 container_of(kobj, struct ttm_pool_manager, kobj); 212 int chars; 213 unsigned val; 214 chars = sscanf(buffer, "%u", &val); 215 if (chars == 0) 216 return size; 217 218 /* Convert kb to number of pages */ 219 val = val / (PAGE_SIZE >> 10); 220 221 if (attr == &ttm_page_pool_max) 222 m->options.max_size = val; 223 else if (attr == &ttm_page_pool_small) 224 m->options.small = val; 225 else if (attr == &ttm_page_pool_alloc_size) { 226 if (val > NUM_PAGES_TO_ALLOC*8) { 227 pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n", 228 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7), 229 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); 230 return size; 231 } else if (val > NUM_PAGES_TO_ALLOC) { 232 pr_warn("Setting allocation size to larger than %lu is not recommended\n", 233 NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10)); 234 } 235 m->options.alloc_size = val; 236 } 237 238 return size; 239} 240 241static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr, 242 char *buffer) 243{ 244 struct ttm_pool_manager *m = 245 container_of(kobj, struct ttm_pool_manager, kobj); 246 unsigned val = 0; 247 248 if (attr == &ttm_page_pool_max) 249 val = m->options.max_size; 250 else if (attr == &ttm_page_pool_small) 251 val = m->options.small; 252 else if (attr == &ttm_page_pool_alloc_size) 253 val = m->options.alloc_size; 254 255 val = val * (PAGE_SIZE >> 10); 256 257 return snprintf(buffer, PAGE_SIZE, "%u\n", val); 258} 259 260static const struct sysfs_ops ttm_pool_sysfs_ops = { 261 .show = &ttm_pool_show, 262 .store = &ttm_pool_store, 263}; 264 265static struct kobj_type ttm_pool_kobj_type = { 266 .release = &ttm_pool_kobj_release, 267 .sysfs_ops = &ttm_pool_sysfs_ops, 268 .default_attrs = ttm_pool_attrs, 269}; 270 271#ifndef CONFIG_X86 272static int set_pages_array_wb(struct page **pages, int addrinarray) 273{ 274#ifdef TTM_HAS_AGP 275 int i; 276 277 for (i = 0; i < addrinarray; i++) 278 unmap_page_from_agp(pages[i]); 279#endif 280 return 0; 281} 282 283static int set_pages_array_wc(struct page **pages, int addrinarray) 284{ 285#ifdef TTM_HAS_AGP 286 int i; 287 288 for (i = 0; i < addrinarray; i++) 289 map_page_into_agp(pages[i]); 290#endif 291 return 0; 292} 293 294static int set_pages_array_uc(struct page **pages, int addrinarray) 295{ 296#ifdef TTM_HAS_AGP 297 int i; 298 299 for (i = 0; i < addrinarray; i++) 300 map_page_into_agp(pages[i]); 301#endif 302 return 0; 303} 304#endif /* for !CONFIG_X86 */ 305 306static int ttm_set_pages_caching(struct dma_pool *pool, 307 struct page **pages, unsigned cpages) 308{ 309 int r = 0; 310 /* Set page caching */ 311 if (pool->type & IS_UC) { 312 r = set_pages_array_uc(pages, cpages); 313 if (r) 314 pr_err("%s: Failed to set %d pages to uc!\n", 315 pool->dev_name, cpages); 316 } 317 if (pool->type & IS_WC) { 318 r = set_pages_array_wc(pages, cpages); 319 if (r) 320 pr_err("%s: Failed to set %d pages to wc!\n", 321 pool->dev_name, cpages); 322 } 323 return r; 324} 325 326static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page) 327{ 328 dma_addr_t dma = d_page->dma; 329 dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma); 330 331 kfree(d_page); 332 d_page = NULL; 333} 334static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool) 335{ 336 struct dma_page *d_page; 337 338 d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL); 339 if (!d_page) 340 return NULL; 341 342 d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size, 343 &d_page->dma, 344 pool->gfp_flags); 345 if (d_page->vaddr) { 346 if (is_vmalloc_addr(d_page->vaddr)) 347 d_page->p = vmalloc_to_page(d_page->vaddr); 348 else 349 d_page->p = virt_to_page(d_page->vaddr); 350 } else { 351 kfree(d_page); 352 d_page = NULL; 353 } 354 return d_page; 355} 356static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate) 357{ 358 enum pool_type type = IS_UNDEFINED; 359 360 if (flags & TTM_PAGE_FLAG_DMA32) 361 type |= IS_DMA32; 362 if (cstate == tt_cached) 363 type |= IS_CACHED; 364 else if (cstate == tt_uncached) 365 type |= IS_UC; 366 else 367 type |= IS_WC; 368 369 return type; 370} 371 372static void ttm_pool_update_free_locked(struct dma_pool *pool, 373 unsigned freed_pages) 374{ 375 pool->npages_free -= freed_pages; 376 pool->nfrees += freed_pages; 377 378} 379 380/* set memory back to wb and free the pages. */ 381static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages, 382 struct page *pages[], unsigned npages) 383{ 384 struct dma_page *d_page, *tmp; 385 386 /* Don't set WB on WB page pool. */ 387 if (npages && !(pool->type & IS_CACHED) && 388 set_pages_array_wb(pages, npages)) 389 pr_err("%s: Failed to set %d pages to wb!\n", 390 pool->dev_name, npages); 391 392 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { 393 list_del(&d_page->page_list); 394 __ttm_dma_free_page(pool, d_page); 395 } 396} 397 398static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page) 399{ 400 /* Don't set WB on WB page pool. */ 401 if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1)) 402 pr_err("%s: Failed to set %d pages to wb!\n", 403 pool->dev_name, 1); 404 405 list_del(&d_page->page_list); 406 __ttm_dma_free_page(pool, d_page); 407} 408 409/* 410 * Free pages from pool. 411 * 412 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC 413 * number of pages in one go. 414 * 415 * @pool: to free the pages from 416 * @nr_free: If set to true will free all pages in pool 417 * @use_static: Safe to use static buffer 418 **/ 419static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free, 420 bool use_static) 421{ 422 static struct page *static_buf[NUM_PAGES_TO_ALLOC]; 423 unsigned long irq_flags; 424 struct dma_page *dma_p, *tmp; 425 struct page **pages_to_free; 426 struct list_head d_pages; 427 unsigned freed_pages = 0, 428 npages_to_free = nr_free; 429 430 if (NUM_PAGES_TO_ALLOC < nr_free) 431 npages_to_free = NUM_PAGES_TO_ALLOC; 432#if 0 433 if (nr_free > 1) { 434 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n", 435 pool->dev_name, pool->name, current->pid, 436 npages_to_free, nr_free); 437 } 438#endif 439 if (use_static) 440 pages_to_free = static_buf; 441 else 442 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), 443 GFP_KERNEL); 444 445 if (!pages_to_free) { 446 pr_err("%s: Failed to allocate memory for pool free operation\n", 447 pool->dev_name); 448 return 0; 449 } 450 INIT_LIST_HEAD(&d_pages); 451restart: 452 spin_lock_irqsave(&pool->lock, irq_flags); 453 454 /* We picking the oldest ones off the list */ 455 list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list, 456 page_list) { 457 if (freed_pages >= npages_to_free) 458 break; 459 460 /* Move the dma_page from one list to another. */ 461 list_move(&dma_p->page_list, &d_pages); 462 463 pages_to_free[freed_pages++] = dma_p->p; 464 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */ 465 if (freed_pages >= NUM_PAGES_TO_ALLOC) { 466 467 ttm_pool_update_free_locked(pool, freed_pages); 468 /** 469 * Because changing page caching is costly 470 * we unlock the pool to prevent stalling. 471 */ 472 spin_unlock_irqrestore(&pool->lock, irq_flags); 473 474 ttm_dma_pages_put(pool, &d_pages, pages_to_free, 475 freed_pages); 476 477 INIT_LIST_HEAD(&d_pages); 478 479 if (likely(nr_free != FREE_ALL_PAGES)) 480 nr_free -= freed_pages; 481 482 if (NUM_PAGES_TO_ALLOC >= nr_free) 483 npages_to_free = nr_free; 484 else 485 npages_to_free = NUM_PAGES_TO_ALLOC; 486 487 freed_pages = 0; 488 489 /* free all so restart the processing */ 490 if (nr_free) 491 goto restart; 492 493 /* Not allowed to fall through or break because 494 * following context is inside spinlock while we are 495 * outside here. 496 */ 497 goto out; 498 499 } 500 } 501 502 /* remove range of pages from the pool */ 503 if (freed_pages) { 504 ttm_pool_update_free_locked(pool, freed_pages); 505 nr_free -= freed_pages; 506 } 507 508 spin_unlock_irqrestore(&pool->lock, irq_flags); 509 510 if (freed_pages) 511 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages); 512out: 513 if (pages_to_free != static_buf) 514 kfree(pages_to_free); 515 return nr_free; 516} 517 518static void ttm_dma_free_pool(struct device *dev, enum pool_type type) 519{ 520 struct device_pools *p; 521 struct dma_pool *pool; 522 523 if (!dev) 524 return; 525 526 mutex_lock(&_manager->lock); 527 list_for_each_entry_reverse(p, &_manager->pools, pools) { 528 if (p->dev != dev) 529 continue; 530 pool = p->pool; 531 if (pool->type != type) 532 continue; 533 534 list_del(&p->pools); 535 kfree(p); 536 _manager->npools--; 537 break; 538 } 539 list_for_each_entry_reverse(pool, &dev->dma_pools, pools) { 540 if (pool->type != type) 541 continue; 542 /* Takes a spinlock.. */ 543 /* OK to use static buffer since global mutex is held. */ 544 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, true); 545 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0)); 546 /* This code path is called after _all_ references to the 547 * struct device has been dropped - so nobody should be 548 * touching it. In case somebody is trying to _add_ we are 549 * guarded by the mutex. */ 550 list_del(&pool->pools); 551 kfree(pool); 552 break; 553 } 554 mutex_unlock(&_manager->lock); 555} 556 557/* 558 * On free-ing of the 'struct device' this deconstructor is run. 559 * Albeit the pool might have already been freed earlier. 560 */ 561static void ttm_dma_pool_release(struct device *dev, void *res) 562{ 563 struct dma_pool *pool = *(struct dma_pool **)res; 564 565 if (pool) 566 ttm_dma_free_pool(dev, pool->type); 567} 568 569static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data) 570{ 571 return *(struct dma_pool **)res == match_data; 572} 573 574static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags, 575 enum pool_type type) 576{ 577 char *n[] = {"wc", "uc", "cached", " dma32", "unknown",}; 578 enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED}; 579 struct device_pools *sec_pool = NULL; 580 struct dma_pool *pool = NULL, **ptr; 581 unsigned i; 582 int ret = -ENODEV; 583 char *p; 584 585 if (!dev) 586 return NULL; 587 588 ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL); 589 if (!ptr) 590 return NULL; 591 592 ret = -ENOMEM; 593 594 pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL, 595 dev_to_node(dev)); 596 if (!pool) 597 goto err_mem; 598 599 sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL, 600 dev_to_node(dev)); 601 if (!sec_pool) 602 goto err_mem; 603 604 INIT_LIST_HEAD(&sec_pool->pools); 605 sec_pool->dev = dev; 606 sec_pool->pool = pool; 607 608 INIT_LIST_HEAD(&pool->free_list); 609 INIT_LIST_HEAD(&pool->inuse_list); 610 INIT_LIST_HEAD(&pool->pools); 611 spin_lock_init(&pool->lock); 612 pool->dev = dev; 613 pool->npages_free = pool->npages_in_use = 0; 614 pool->nfrees = 0; 615 pool->gfp_flags = flags; 616 pool->size = PAGE_SIZE; 617 pool->type = type; 618 pool->nrefills = 0; 619 p = pool->name; 620 for (i = 0; i < 5; i++) { 621 if (type & t[i]) { 622 p += snprintf(p, sizeof(pool->name) - (p - pool->name), 623 "%s", n[i]); 624 } 625 } 626 *p = 0; 627 /* We copy the name for pr_ calls b/c when dma_pool_destroy is called 628 * - the kobj->name has already been deallocated.*/ 629 snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s", 630 dev_driver_string(dev), dev_name(dev)); 631 mutex_lock(&_manager->lock); 632 /* You can get the dma_pool from either the global: */ 633 list_add(&sec_pool->pools, &_manager->pools); 634 _manager->npools++; 635 /* or from 'struct device': */ 636 list_add(&pool->pools, &dev->dma_pools); 637 mutex_unlock(&_manager->lock); 638 639 *ptr = pool; 640 devres_add(dev, ptr); 641 642 return pool; 643err_mem: 644 devres_free(ptr); 645 kfree(sec_pool); 646 kfree(pool); 647 return ERR_PTR(ret); 648} 649 650static struct dma_pool *ttm_dma_find_pool(struct device *dev, 651 enum pool_type type) 652{ 653 struct dma_pool *pool, *tmp, *found = NULL; 654 655 if (type == IS_UNDEFINED) 656 return found; 657 658 /* NB: We iterate on the 'struct dev' which has no spinlock, but 659 * it does have a kref which we have taken. The kref is taken during 660 * graphic driver loading - in the drm_pci_init it calls either 661 * pci_dev_get or pci_register_driver which both end up taking a kref 662 * on 'struct device'. 663 * 664 * On teardown, the graphic drivers end up quiescing the TTM (put_pages) 665 * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice 666 * thing is at that point of time there are no pages associated with the 667 * driver so this function will not be called. 668 */ 669 list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) { 670 if (pool->type != type) 671 continue; 672 found = pool; 673 break; 674 } 675 return found; 676} 677 678/* 679 * Free pages the pages that failed to change the caching state. If there 680 * are pages that have changed their caching state already put them to the 681 * pool. 682 */ 683static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool, 684 struct list_head *d_pages, 685 struct page **failed_pages, 686 unsigned cpages) 687{ 688 struct dma_page *d_page, *tmp; 689 struct page *p; 690 unsigned i = 0; 691 692 p = failed_pages[0]; 693 if (!p) 694 return; 695 /* Find the failed page. */ 696 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { 697 if (d_page->p != p) 698 continue; 699 /* .. and then progress over the full list. */ 700 list_del(&d_page->page_list); 701 __ttm_dma_free_page(pool, d_page); 702 if (++i < cpages) 703 p = failed_pages[i]; 704 else 705 break; 706 } 707 708} 709 710/* 711 * Allocate 'count' pages, and put 'need' number of them on the 712 * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset. 713 * The full list of pages should also be on 'd_pages'. 714 * We return zero for success, and negative numbers as errors. 715 */ 716static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool, 717 struct list_head *d_pages, 718 unsigned count) 719{ 720 struct page **caching_array; 721 struct dma_page *dma_p; 722 struct page *p; 723 int r = 0; 724 unsigned i, cpages; 725 unsigned max_cpages = min(count, 726 (unsigned)(PAGE_SIZE/sizeof(struct page *))); 727 728 /* allocate array for page caching change */ 729 caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL); 730 731 if (!caching_array) { 732 pr_err("%s: Unable to allocate table for new pages\n", 733 pool->dev_name); 734 return -ENOMEM; 735 } 736 737 if (count > 1) { 738 pr_debug("%s: (%s:%d) Getting %d pages\n", 739 pool->dev_name, pool->name, current->pid, count); 740 } 741 742 for (i = 0, cpages = 0; i < count; ++i) { 743 dma_p = __ttm_dma_alloc_page(pool); 744 if (!dma_p) { 745 pr_err("%s: Unable to get page %u\n", 746 pool->dev_name, i); 747 748 /* store already allocated pages in the pool after 749 * setting the caching state */ 750 if (cpages) { 751 r = ttm_set_pages_caching(pool, caching_array, 752 cpages); 753 if (r) 754 ttm_dma_handle_caching_state_failure( 755 pool, d_pages, caching_array, 756 cpages); 757 } 758 r = -ENOMEM; 759 goto out; 760 } 761 p = dma_p->p; 762#ifdef CONFIG_HIGHMEM 763 /* gfp flags of highmem page should never be dma32 so we 764 * we should be fine in such case 765 */ 766 if (!PageHighMem(p)) 767#endif 768 { 769 caching_array[cpages++] = p; 770 if (cpages == max_cpages) { 771 /* Note: Cannot hold the spinlock */ 772 r = ttm_set_pages_caching(pool, caching_array, 773 cpages); 774 if (r) { 775 ttm_dma_handle_caching_state_failure( 776 pool, d_pages, caching_array, 777 cpages); 778 goto out; 779 } 780 cpages = 0; 781 } 782 } 783 list_add(&dma_p->page_list, d_pages); 784 } 785 786 if (cpages) { 787 r = ttm_set_pages_caching(pool, caching_array, cpages); 788 if (r) 789 ttm_dma_handle_caching_state_failure(pool, d_pages, 790 caching_array, cpages); 791 } 792out: 793 kfree(caching_array); 794 return r; 795} 796 797/* 798 * @return count of pages still required to fulfill the request. 799 */ 800static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool, 801 unsigned long *irq_flags) 802{ 803 unsigned count = _manager->options.small; 804 int r = pool->npages_free; 805 806 if (count > pool->npages_free) { 807 struct list_head d_pages; 808 809 INIT_LIST_HEAD(&d_pages); 810 811 spin_unlock_irqrestore(&pool->lock, *irq_flags); 812 813 /* Returns how many more are neccessary to fulfill the 814 * request. */ 815 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count); 816 817 spin_lock_irqsave(&pool->lock, *irq_flags); 818 if (!r) { 819 /* Add the fresh to the end.. */ 820 list_splice(&d_pages, &pool->free_list); 821 ++pool->nrefills; 822 pool->npages_free += count; 823 r = count; 824 } else { 825 struct dma_page *d_page; 826 unsigned cpages = 0; 827 828 pr_err("%s: Failed to fill %s pool (r:%d)!\n", 829 pool->dev_name, pool->name, r); 830 831 list_for_each_entry(d_page, &d_pages, page_list) { 832 cpages++; 833 } 834 list_splice_tail(&d_pages, &pool->free_list); 835 pool->npages_free += cpages; 836 r = cpages; 837 } 838 } 839 return r; 840} 841 842/* 843 * @return count of pages still required to fulfill the request. 844 * The populate list is actually a stack (not that is matters as TTM 845 * allocates one page at a time. 846 */ 847static int ttm_dma_pool_get_pages(struct dma_pool *pool, 848 struct ttm_dma_tt *ttm_dma, 849 unsigned index) 850{ 851 struct dma_page *d_page; 852 struct ttm_tt *ttm = &ttm_dma->ttm; 853 unsigned long irq_flags; 854 int count, r = -ENOMEM; 855 856 spin_lock_irqsave(&pool->lock, irq_flags); 857 count = ttm_dma_page_pool_fill_locked(pool, &irq_flags); 858 if (count) { 859 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list); 860 ttm->pages[index] = d_page->p; 861 ttm_dma->cpu_address[index] = d_page->vaddr; 862 ttm_dma->dma_address[index] = d_page->dma; 863 list_move_tail(&d_page->page_list, &ttm_dma->pages_list); 864 r = 0; 865 pool->npages_in_use += 1; 866 pool->npages_free -= 1; 867 } 868 spin_unlock_irqrestore(&pool->lock, irq_flags); 869 return r; 870} 871 872/* 873 * On success pages list will hold count number of correctly 874 * cached pages. On failure will hold the negative return value (-ENOMEM, etc). 875 */ 876int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev) 877{ 878 struct ttm_tt *ttm = &ttm_dma->ttm; 879 struct ttm_mem_global *mem_glob = ttm->glob->mem_glob; 880 struct dma_pool *pool; 881 enum pool_type type; 882 unsigned i; 883 gfp_t gfp_flags; 884 int ret; 885 886 if (ttm->state != tt_unpopulated) 887 return 0; 888 889 type = ttm_to_type(ttm->page_flags, ttm->caching_state); 890 if (ttm->page_flags & TTM_PAGE_FLAG_DMA32) 891 gfp_flags = GFP_USER | GFP_DMA32; 892 else 893 gfp_flags = GFP_HIGHUSER; 894 if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC) 895 gfp_flags |= __GFP_ZERO; 896 897 pool = ttm_dma_find_pool(dev, type); 898 if (!pool) { 899 pool = ttm_dma_pool_init(dev, gfp_flags, type); 900 if (IS_ERR_OR_NULL(pool)) { 901 return -ENOMEM; 902 } 903 } 904 905 INIT_LIST_HEAD(&ttm_dma->pages_list); 906 for (i = 0; i < ttm->num_pages; ++i) { 907 ret = ttm_dma_pool_get_pages(pool, ttm_dma, i); 908 if (ret != 0) { 909 ttm_dma_unpopulate(ttm_dma, dev); 910 return -ENOMEM; 911 } 912 913 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i], 914 false, false); 915 if (unlikely(ret != 0)) { 916 ttm_dma_unpopulate(ttm_dma, dev); 917 return -ENOMEM; 918 } 919 } 920 921 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) { 922 ret = ttm_tt_swapin(ttm); 923 if (unlikely(ret != 0)) { 924 ttm_dma_unpopulate(ttm_dma, dev); 925 return ret; 926 } 927 } 928 929 ttm->state = tt_unbound; 930 return 0; 931} 932EXPORT_SYMBOL_GPL(ttm_dma_populate); 933 934/* Put all pages in pages list to correct pool to wait for reuse */ 935void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) 936{ 937 struct ttm_tt *ttm = &ttm_dma->ttm; 938 struct dma_pool *pool; 939 struct dma_page *d_page, *next; 940 enum pool_type type; 941 bool is_cached = false; 942 unsigned count = 0, i, npages = 0; 943 unsigned long irq_flags; 944 945 type = ttm_to_type(ttm->page_flags, ttm->caching_state); 946 pool = ttm_dma_find_pool(dev, type); 947 if (!pool) 948 return; 949 950 is_cached = (ttm_dma_find_pool(pool->dev, 951 ttm_to_type(ttm->page_flags, tt_cached)) == pool); 952 953 /* make sure pages array match list and count number of pages */ 954 list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) { 955 ttm->pages[count] = d_page->p; 956 count++; 957 } 958 959 spin_lock_irqsave(&pool->lock, irq_flags); 960 pool->npages_in_use -= count; 961 if (is_cached) { 962 pool->nfrees += count; 963 } else { 964 pool->npages_free += count; 965 list_splice(&ttm_dma->pages_list, &pool->free_list); 966 /* 967 * Wait to have at at least NUM_PAGES_TO_ALLOC number of pages 968 * to free in order to minimize calls to set_memory_wb(). 969 */ 970 if (pool->npages_free >= (_manager->options.max_size + 971 NUM_PAGES_TO_ALLOC)) 972 npages = pool->npages_free - _manager->options.max_size; 973 } 974 spin_unlock_irqrestore(&pool->lock, irq_flags); 975 976 if (is_cached) { 977 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) { 978 ttm_mem_global_free_page(ttm->glob->mem_glob, 979 d_page->p); 980 ttm_dma_page_put(pool, d_page); 981 } 982 } else { 983 for (i = 0; i < count; i++) { 984 ttm_mem_global_free_page(ttm->glob->mem_glob, 985 ttm->pages[i]); 986 } 987 } 988 989 INIT_LIST_HEAD(&ttm_dma->pages_list); 990 for (i = 0; i < ttm->num_pages; i++) { 991 ttm->pages[i] = NULL; 992 ttm_dma->cpu_address[i] = 0; 993 ttm_dma->dma_address[i] = 0; 994 } 995 996 /* shrink pool if necessary (only on !is_cached pools)*/ 997 if (npages) 998 ttm_dma_page_pool_free(pool, npages, false); 999 ttm->state = tt_unpopulated; 1000} 1001EXPORT_SYMBOL_GPL(ttm_dma_unpopulate); 1002 1003/** 1004 * Callback for mm to request pool to reduce number of page held. 1005 * 1006 * XXX: (dchinner) Deadlock warning! 1007 * 1008 * I'm getting sadder as I hear more pathetical whimpers about needing per-pool 1009 * shrinkers 1010 */ 1011static unsigned long 1012ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 1013{ 1014 static unsigned start_pool; 1015 unsigned idx = 0; 1016 unsigned pool_offset; 1017 unsigned shrink_pages = sc->nr_to_scan; 1018 struct device_pools *p; 1019 unsigned long freed = 0; 1020 1021 if (list_empty(&_manager->pools)) 1022 return SHRINK_STOP; 1023 1024 if (!mutex_trylock(&_manager->lock)) 1025 return SHRINK_STOP; 1026 if (!_manager->npools) 1027 goto out; 1028 pool_offset = ++start_pool % _manager->npools; 1029 list_for_each_entry(p, &_manager->pools, pools) { 1030 unsigned nr_free; 1031 1032 if (!p->dev) 1033 continue; 1034 if (shrink_pages == 0) 1035 break; 1036 /* Do it in round-robin fashion. */ 1037 if (++idx < pool_offset) 1038 continue; 1039 nr_free = shrink_pages; 1040 /* OK to use static buffer since global mutex is held. */ 1041 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free, true); 1042 freed += nr_free - shrink_pages; 1043 1044 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n", 1045 p->pool->dev_name, p->pool->name, current->pid, 1046 nr_free, shrink_pages); 1047 } 1048out: 1049 mutex_unlock(&_manager->lock); 1050 return freed; 1051} 1052 1053static unsigned long 1054ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 1055{ 1056 struct device_pools *p; 1057 unsigned long count = 0; 1058 1059 if (!mutex_trylock(&_manager->lock)) 1060 return 0; 1061 list_for_each_entry(p, &_manager->pools, pools) 1062 count += p->pool->npages_free; 1063 mutex_unlock(&_manager->lock); 1064 return count; 1065} 1066 1067static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager) 1068{ 1069 manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count; 1070 manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan; 1071 manager->mm_shrink.seeks = 1; 1072 register_shrinker(&manager->mm_shrink); 1073} 1074 1075static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager) 1076{ 1077 unregister_shrinker(&manager->mm_shrink); 1078} 1079 1080int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) 1081{ 1082 int ret = -ENOMEM; 1083 1084 WARN_ON(_manager); 1085 1086 pr_info("Initializing DMA pool allocator\n"); 1087 1088 _manager = kzalloc(sizeof(*_manager), GFP_KERNEL); 1089 if (!_manager) 1090 goto err; 1091 1092 mutex_init(&_manager->lock); 1093 INIT_LIST_HEAD(&_manager->pools); 1094 1095 _manager->options.max_size = max_pages; 1096 _manager->options.small = SMALL_ALLOCATION; 1097 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC; 1098 1099 /* This takes care of auto-freeing the _manager */ 1100 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type, 1101 &glob->kobj, "dma_pool"); 1102 if (unlikely(ret != 0)) { 1103 kobject_put(&_manager->kobj); 1104 goto err; 1105 } 1106 ttm_dma_pool_mm_shrink_init(_manager); 1107 return 0; 1108err: 1109 return ret; 1110} 1111 1112void ttm_dma_page_alloc_fini(void) 1113{ 1114 struct device_pools *p, *t; 1115 1116 pr_info("Finalizing DMA pool allocator\n"); 1117 ttm_dma_pool_mm_shrink_fini(_manager); 1118 1119 list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) { 1120 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name, 1121 current->pid); 1122 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release, 1123 ttm_dma_pool_match, p->pool)); 1124 ttm_dma_free_pool(p->dev, p->pool->type); 1125 } 1126 kobject_put(&_manager->kobj); 1127 _manager = NULL; 1128} 1129 1130int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data) 1131{ 1132 struct device_pools *p; 1133 struct dma_pool *pool = NULL; 1134 char *h[] = {"pool", "refills", "pages freed", "inuse", "available", 1135 "name", "virt", "busaddr"}; 1136 1137 if (!_manager) { 1138 seq_printf(m, "No pool allocator running.\n"); 1139 return 0; 1140 } 1141 seq_printf(m, "%13s %12s %13s %8s %8s %8s\n", 1142 h[0], h[1], h[2], h[3], h[4], h[5]); 1143 mutex_lock(&_manager->lock); 1144 list_for_each_entry(p, &_manager->pools, pools) { 1145 struct device *dev = p->dev; 1146 if (!dev) 1147 continue; 1148 pool = p->pool; 1149 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n", 1150 pool->name, pool->nrefills, 1151 pool->nfrees, pool->npages_in_use, 1152 pool->npages_free, 1153 pool->dev_name); 1154 } 1155 mutex_unlock(&_manager->lock); 1156 return 0; 1157} 1158EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs); 1159 1160#endif 1161