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#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 necessary. 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 d_page->p = virt_to_page(d_page->vaddr); 347 else { 348 kfree(d_page); 349 d_page = NULL; 350 } 351 return d_page; 352} 353static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate) 354{ 355 enum pool_type type = IS_UNDEFINED; 356 357 if (flags & TTM_PAGE_FLAG_DMA32) 358 type |= IS_DMA32; 359 if (cstate == tt_cached) 360 type |= IS_CACHED; 361 else if (cstate == tt_uncached) 362 type |= IS_UC; 363 else 364 type |= IS_WC; 365 366 return type; 367} 368 369static void ttm_pool_update_free_locked(struct dma_pool *pool, 370 unsigned freed_pages) 371{ 372 pool->npages_free -= freed_pages; 373 pool->nfrees += freed_pages; 374 375} 376 377/* set memory back to wb and free the pages. */ 378static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages, 379 struct page *pages[], unsigned npages) 380{ 381 struct dma_page *d_page, *tmp; 382 383 /* Don't set WB on WB page pool. */ 384 if (npages && !(pool->type & IS_CACHED) && 385 set_pages_array_wb(pages, npages)) 386 pr_err("%s: Failed to set %d pages to wb!\n", 387 pool->dev_name, npages); 388 389 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { 390 list_del(&d_page->page_list); 391 __ttm_dma_free_page(pool, d_page); 392 } 393} 394 395static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page) 396{ 397 /* Don't set WB on WB page pool. */ 398 if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1)) 399 pr_err("%s: Failed to set %d pages to wb!\n", 400 pool->dev_name, 1); 401 402 list_del(&d_page->page_list); 403 __ttm_dma_free_page(pool, d_page); 404} 405 406/* 407 * Free pages from pool. 408 * 409 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC 410 * number of pages in one go. 411 * 412 * @pool: to free the pages from 413 * @nr_free: If set to true will free all pages in pool 414 **/ 415static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free) 416{ 417 unsigned long irq_flags; 418 struct dma_page *dma_p, *tmp; 419 struct page **pages_to_free; 420 struct list_head d_pages; 421 unsigned freed_pages = 0, 422 npages_to_free = nr_free; 423 424 if (NUM_PAGES_TO_ALLOC < nr_free) 425 npages_to_free = NUM_PAGES_TO_ALLOC; 426#if 0 427 if (nr_free > 1) { 428 pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n", 429 pool->dev_name, pool->name, current->pid, 430 npages_to_free, nr_free); 431 } 432#endif 433 pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), 434 GFP_KERNEL); 435 436 if (!pages_to_free) { 437 pr_err("%s: Failed to allocate memory for pool free operation\n", 438 pool->dev_name); 439 return 0; 440 } 441 INIT_LIST_HEAD(&d_pages); 442restart: 443 spin_lock_irqsave(&pool->lock, irq_flags); 444 445 /* We picking the oldest ones off the list */ 446 list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list, 447 page_list) { 448 if (freed_pages >= npages_to_free) 449 break; 450 451 /* Move the dma_page from one list to another. */ 452 list_move(&dma_p->page_list, &d_pages); 453 454 pages_to_free[freed_pages++] = dma_p->p; 455 /* We can only remove NUM_PAGES_TO_ALLOC at a time. */ 456 if (freed_pages >= NUM_PAGES_TO_ALLOC) { 457 458 ttm_pool_update_free_locked(pool, freed_pages); 459 /** 460 * Because changing page caching is costly 461 * we unlock the pool to prevent stalling. 462 */ 463 spin_unlock_irqrestore(&pool->lock, irq_flags); 464 465 ttm_dma_pages_put(pool, &d_pages, pages_to_free, 466 freed_pages); 467 468 INIT_LIST_HEAD(&d_pages); 469 470 if (likely(nr_free != FREE_ALL_PAGES)) 471 nr_free -= freed_pages; 472 473 if (NUM_PAGES_TO_ALLOC >= nr_free) 474 npages_to_free = nr_free; 475 else 476 npages_to_free = NUM_PAGES_TO_ALLOC; 477 478 freed_pages = 0; 479 480 /* free all so restart the processing */ 481 if (nr_free) 482 goto restart; 483 484 /* Not allowed to fall through or break because 485 * following context is inside spinlock while we are 486 * outside here. 487 */ 488 goto out; 489 490 } 491 } 492 493 /* remove range of pages from the pool */ 494 if (freed_pages) { 495 ttm_pool_update_free_locked(pool, freed_pages); 496 nr_free -= freed_pages; 497 } 498 499 spin_unlock_irqrestore(&pool->lock, irq_flags); 500 501 if (freed_pages) 502 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages); 503out: 504 kfree(pages_to_free); 505 return nr_free; 506} 507 508static void ttm_dma_free_pool(struct device *dev, enum pool_type type) 509{ 510 struct device_pools *p; 511 struct dma_pool *pool; 512 513 if (!dev) 514 return; 515 516 mutex_lock(&_manager->lock); 517 list_for_each_entry_reverse(p, &_manager->pools, pools) { 518 if (p->dev != dev) 519 continue; 520 pool = p->pool; 521 if (pool->type != type) 522 continue; 523 524 list_del(&p->pools); 525 kfree(p); 526 _manager->npools--; 527 break; 528 } 529 list_for_each_entry_reverse(pool, &dev->dma_pools, pools) { 530 if (pool->type != type) 531 continue; 532 /* Takes a spinlock.. */ 533 ttm_dma_page_pool_free(pool, FREE_ALL_PAGES); 534 WARN_ON(((pool->npages_in_use + pool->npages_free) != 0)); 535 /* This code path is called after _all_ references to the 536 * struct device has been dropped - so nobody should be 537 * touching it. In case somebody is trying to _add_ we are 538 * guarded by the mutex. */ 539 list_del(&pool->pools); 540 kfree(pool); 541 break; 542 } 543 mutex_unlock(&_manager->lock); 544} 545 546/* 547 * On free-ing of the 'struct device' this deconstructor is run. 548 * Albeit the pool might have already been freed earlier. 549 */ 550static void ttm_dma_pool_release(struct device *dev, void *res) 551{ 552 struct dma_pool *pool = *(struct dma_pool **)res; 553 554 if (pool) 555 ttm_dma_free_pool(dev, pool->type); 556} 557 558static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data) 559{ 560 return *(struct dma_pool **)res == match_data; 561} 562 563static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags, 564 enum pool_type type) 565{ 566 char *n[] = {"wc", "uc", "cached", " dma32", "unknown",}; 567 enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED}; 568 struct device_pools *sec_pool = NULL; 569 struct dma_pool *pool = NULL, **ptr; 570 unsigned i; 571 int ret = -ENODEV; 572 char *p; 573 574 if (!dev) 575 return NULL; 576 577 ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL); 578 if (!ptr) 579 return NULL; 580 581 ret = -ENOMEM; 582 583 pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL, 584 dev_to_node(dev)); 585 if (!pool) 586 goto err_mem; 587 588 sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL, 589 dev_to_node(dev)); 590 if (!sec_pool) 591 goto err_mem; 592 593 INIT_LIST_HEAD(&sec_pool->pools); 594 sec_pool->dev = dev; 595 sec_pool->pool = pool; 596 597 INIT_LIST_HEAD(&pool->free_list); 598 INIT_LIST_HEAD(&pool->inuse_list); 599 INIT_LIST_HEAD(&pool->pools); 600 spin_lock_init(&pool->lock); 601 pool->dev = dev; 602 pool->npages_free = pool->npages_in_use = 0; 603 pool->nfrees = 0; 604 pool->gfp_flags = flags; 605 pool->size = PAGE_SIZE; 606 pool->type = type; 607 pool->nrefills = 0; 608 p = pool->name; 609 for (i = 0; i < 5; i++) { 610 if (type & t[i]) { 611 p += snprintf(p, sizeof(pool->name) - (p - pool->name), 612 "%s", n[i]); 613 } 614 } 615 *p = 0; 616 /* We copy the name for pr_ calls b/c when dma_pool_destroy is called 617 * - the kobj->name has already been deallocated.*/ 618 snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s", 619 dev_driver_string(dev), dev_name(dev)); 620 mutex_lock(&_manager->lock); 621 /* You can get the dma_pool from either the global: */ 622 list_add(&sec_pool->pools, &_manager->pools); 623 _manager->npools++; 624 /* or from 'struct device': */ 625 list_add(&pool->pools, &dev->dma_pools); 626 mutex_unlock(&_manager->lock); 627 628 *ptr = pool; 629 devres_add(dev, ptr); 630 631 return pool; 632err_mem: 633 devres_free(ptr); 634 kfree(sec_pool); 635 kfree(pool); 636 return ERR_PTR(ret); 637} 638 639static struct dma_pool *ttm_dma_find_pool(struct device *dev, 640 enum pool_type type) 641{ 642 struct dma_pool *pool, *tmp, *found = NULL; 643 644 if (type == IS_UNDEFINED) 645 return found; 646 647 /* NB: We iterate on the 'struct dev' which has no spinlock, but 648 * it does have a kref which we have taken. The kref is taken during 649 * graphic driver loading - in the drm_pci_init it calls either 650 * pci_dev_get or pci_register_driver which both end up taking a kref 651 * on 'struct device'. 652 * 653 * On teardown, the graphic drivers end up quiescing the TTM (put_pages) 654 * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice 655 * thing is at that point of time there are no pages associated with the 656 * driver so this function will not be called. 657 */ 658 list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) { 659 if (pool->type != type) 660 continue; 661 found = pool; 662 break; 663 } 664 return found; 665} 666 667/* 668 * Free pages the pages that failed to change the caching state. If there 669 * are pages that have changed their caching state already put them to the 670 * pool. 671 */ 672static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool, 673 struct list_head *d_pages, 674 struct page **failed_pages, 675 unsigned cpages) 676{ 677 struct dma_page *d_page, *tmp; 678 struct page *p; 679 unsigned i = 0; 680 681 p = failed_pages[0]; 682 if (!p) 683 return; 684 /* Find the failed page. */ 685 list_for_each_entry_safe(d_page, tmp, d_pages, page_list) { 686 if (d_page->p != p) 687 continue; 688 /* .. and then progress over the full list. */ 689 list_del(&d_page->page_list); 690 __ttm_dma_free_page(pool, d_page); 691 if (++i < cpages) 692 p = failed_pages[i]; 693 else 694 break; 695 } 696 697} 698 699/* 700 * Allocate 'count' pages, and put 'need' number of them on the 701 * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset. 702 * The full list of pages should also be on 'd_pages'. 703 * We return zero for success, and negative numbers as errors. 704 */ 705static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool, 706 struct list_head *d_pages, 707 unsigned count) 708{ 709 struct page **caching_array; 710 struct dma_page *dma_p; 711 struct page *p; 712 int r = 0; 713 unsigned i, cpages; 714 unsigned max_cpages = min(count, 715 (unsigned)(PAGE_SIZE/sizeof(struct page *))); 716 717 /* allocate array for page caching change */ 718 caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL); 719 720 if (!caching_array) { 721 pr_err("%s: Unable to allocate table for new pages\n", 722 pool->dev_name); 723 return -ENOMEM; 724 } 725 726 if (count > 1) { 727 pr_debug("%s: (%s:%d) Getting %d pages\n", 728 pool->dev_name, pool->name, current->pid, count); 729 } 730 731 for (i = 0, cpages = 0; i < count; ++i) { 732 dma_p = __ttm_dma_alloc_page(pool); 733 if (!dma_p) { 734 pr_err("%s: Unable to get page %u\n", 735 pool->dev_name, i); 736 737 /* store already allocated pages in the pool after 738 * setting the caching state */ 739 if (cpages) { 740 r = ttm_set_pages_caching(pool, caching_array, 741 cpages); 742 if (r) 743 ttm_dma_handle_caching_state_failure( 744 pool, d_pages, caching_array, 745 cpages); 746 } 747 r = -ENOMEM; 748 goto out; 749 } 750 p = dma_p->p; 751#ifdef CONFIG_HIGHMEM 752 /* gfp flags of highmem page should never be dma32 so we 753 * we should be fine in such case 754 */ 755 if (!PageHighMem(p)) 756#endif 757 { 758 caching_array[cpages++] = p; 759 if (cpages == max_cpages) { 760 /* Note: Cannot hold the spinlock */ 761 r = ttm_set_pages_caching(pool, caching_array, 762 cpages); 763 if (r) { 764 ttm_dma_handle_caching_state_failure( 765 pool, d_pages, caching_array, 766 cpages); 767 goto out; 768 } 769 cpages = 0; 770 } 771 } 772 list_add(&dma_p->page_list, d_pages); 773 } 774 775 if (cpages) { 776 r = ttm_set_pages_caching(pool, caching_array, cpages); 777 if (r) 778 ttm_dma_handle_caching_state_failure(pool, d_pages, 779 caching_array, cpages); 780 } 781out: 782 kfree(caching_array); 783 return r; 784} 785 786/* 787 * @return count of pages still required to fulfill the request. 788 */ 789static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool, 790 unsigned long *irq_flags) 791{ 792 unsigned count = _manager->options.small; 793 int r = pool->npages_free; 794 795 if (count > pool->npages_free) { 796 struct list_head d_pages; 797 798 INIT_LIST_HEAD(&d_pages); 799 800 spin_unlock_irqrestore(&pool->lock, *irq_flags); 801 802 /* Returns how many more are necessary to fulfill the 803 * request. */ 804 r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count); 805 806 spin_lock_irqsave(&pool->lock, *irq_flags); 807 if (!r) { 808 /* Add the fresh to the end.. */ 809 list_splice(&d_pages, &pool->free_list); 810 ++pool->nrefills; 811 pool->npages_free += count; 812 r = count; 813 } else { 814 struct dma_page *d_page; 815 unsigned cpages = 0; 816 817 pr_err("%s: Failed to fill %s pool (r:%d)!\n", 818 pool->dev_name, pool->name, r); 819 820 list_for_each_entry(d_page, &d_pages, page_list) { 821 cpages++; 822 } 823 list_splice_tail(&d_pages, &pool->free_list); 824 pool->npages_free += cpages; 825 r = cpages; 826 } 827 } 828 return r; 829} 830 831/* 832 * @return count of pages still required to fulfill the request. 833 * The populate list is actually a stack (not that is matters as TTM 834 * allocates one page at a time. 835 */ 836static int ttm_dma_pool_get_pages(struct dma_pool *pool, 837 struct ttm_dma_tt *ttm_dma, 838 unsigned index) 839{ 840 struct dma_page *d_page; 841 struct ttm_tt *ttm = &ttm_dma->ttm; 842 unsigned long irq_flags; 843 int count, r = -ENOMEM; 844 845 spin_lock_irqsave(&pool->lock, irq_flags); 846 count = ttm_dma_page_pool_fill_locked(pool, &irq_flags); 847 if (count) { 848 d_page = list_first_entry(&pool->free_list, struct dma_page, page_list); 849 ttm->pages[index] = d_page->p; 850 ttm_dma->dma_address[index] = d_page->dma; 851 list_move_tail(&d_page->page_list, &ttm_dma->pages_list); 852 r = 0; 853 pool->npages_in_use += 1; 854 pool->npages_free -= 1; 855 } 856 spin_unlock_irqrestore(&pool->lock, irq_flags); 857 return r; 858} 859 860/* 861 * On success pages list will hold count number of correctly 862 * cached pages. On failure will hold the negative return value (-ENOMEM, etc). 863 */ 864int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev) 865{ 866 struct ttm_tt *ttm = &ttm_dma->ttm; 867 struct ttm_mem_global *mem_glob = ttm->glob->mem_glob; 868 struct dma_pool *pool; 869 enum pool_type type; 870 unsigned i; 871 gfp_t gfp_flags; 872 int ret; 873 874 if (ttm->state != tt_unpopulated) 875 return 0; 876 877 type = ttm_to_type(ttm->page_flags, ttm->caching_state); 878 if (ttm->page_flags & TTM_PAGE_FLAG_DMA32) 879 gfp_flags = GFP_USER | GFP_DMA32; 880 else 881 gfp_flags = GFP_HIGHUSER; 882 if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC) 883 gfp_flags |= __GFP_ZERO; 884 885 pool = ttm_dma_find_pool(dev, type); 886 if (!pool) { 887 pool = ttm_dma_pool_init(dev, gfp_flags, type); 888 if (IS_ERR_OR_NULL(pool)) { 889 return -ENOMEM; 890 } 891 } 892 893 INIT_LIST_HEAD(&ttm_dma->pages_list); 894 for (i = 0; i < ttm->num_pages; ++i) { 895 ret = ttm_dma_pool_get_pages(pool, ttm_dma, i); 896 if (ret != 0) { 897 ttm_dma_unpopulate(ttm_dma, dev); 898 return -ENOMEM; 899 } 900 901 ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i], 902 false, false); 903 if (unlikely(ret != 0)) { 904 ttm_dma_unpopulate(ttm_dma, dev); 905 return -ENOMEM; 906 } 907 } 908 909 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) { 910 ret = ttm_tt_swapin(ttm); 911 if (unlikely(ret != 0)) { 912 ttm_dma_unpopulate(ttm_dma, dev); 913 return ret; 914 } 915 } 916 917 ttm->state = tt_unbound; 918 return 0; 919} 920EXPORT_SYMBOL_GPL(ttm_dma_populate); 921 922/* Get good estimation how many pages are free in pools */ 923static int ttm_dma_pool_get_num_unused_pages(void) 924{ 925 struct device_pools *p; 926 unsigned total = 0; 927 928 mutex_lock(&_manager->lock); 929 list_for_each_entry(p, &_manager->pools, pools) 930 total += p->pool->npages_free; 931 mutex_unlock(&_manager->lock); 932 return total; 933} 934 935/* Put all pages in pages list to correct pool to wait for reuse */ 936void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) 937{ 938 struct ttm_tt *ttm = &ttm_dma->ttm; 939 struct dma_pool *pool; 940 struct dma_page *d_page, *next; 941 enum pool_type type; 942 bool is_cached = false; 943 unsigned count = 0, i, npages = 0; 944 unsigned long irq_flags; 945 946 type = ttm_to_type(ttm->page_flags, ttm->caching_state); 947 pool = ttm_dma_find_pool(dev, type); 948 if (!pool) 949 return; 950 951 is_cached = (ttm_dma_find_pool(pool->dev, 952 ttm_to_type(ttm->page_flags, tt_cached)) == pool); 953 954 /* make sure pages array match list and count number of pages */ 955 list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) { 956 ttm->pages[count] = d_page->p; 957 count++; 958 } 959 960 spin_lock_irqsave(&pool->lock, irq_flags); 961 pool->npages_in_use -= count; 962 if (is_cached) { 963 pool->nfrees += count; 964 } else { 965 pool->npages_free += count; 966 list_splice(&ttm_dma->pages_list, &pool->free_list); 967 npages = count; 968 if (pool->npages_free > _manager->options.max_size) { 969 npages = pool->npages_free - _manager->options.max_size; 970 /* free at least NUM_PAGES_TO_ALLOC number of pages 971 * to reduce calls to set_memory_wb */ 972 if (npages < NUM_PAGES_TO_ALLOC) 973 npages = NUM_PAGES_TO_ALLOC; 974 } 975 } 976 spin_unlock_irqrestore(&pool->lock, irq_flags); 977 978 if (is_cached) { 979 list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) { 980 ttm_mem_global_free_page(ttm->glob->mem_glob, 981 d_page->p); 982 ttm_dma_page_put(pool, d_page); 983 } 984 } else { 985 for (i = 0; i < count; i++) { 986 ttm_mem_global_free_page(ttm->glob->mem_glob, 987 ttm->pages[i]); 988 } 989 } 990 991 INIT_LIST_HEAD(&ttm_dma->pages_list); 992 for (i = 0; i < ttm->num_pages; i++) { 993 ttm->pages[i] = NULL; 994 ttm_dma->dma_address[i] = 0; 995 } 996 997 /* shrink pool if necessary (only on !is_cached pools)*/ 998 if (npages) 999 ttm_dma_page_pool_free(pool, npages); 1000 ttm->state = tt_unpopulated; 1001} 1002EXPORT_SYMBOL_GPL(ttm_dma_unpopulate); 1003 1004/** 1005 * Callback for mm to request pool to reduce number of page held. 1006 */ 1007static int ttm_dma_pool_mm_shrink(struct shrinker *shrink, 1008 struct shrink_control *sc) 1009{ 1010 static atomic_t start_pool = ATOMIC_INIT(0); 1011 unsigned idx = 0; 1012 unsigned pool_offset = atomic_add_return(1, &start_pool); 1013 unsigned shrink_pages = sc->nr_to_scan; 1014 struct device_pools *p; 1015 1016 if (list_empty(&_manager->pools)) 1017 return 0; 1018 1019 mutex_lock(&_manager->lock); 1020 pool_offset = pool_offset % _manager->npools; 1021 list_for_each_entry(p, &_manager->pools, pools) { 1022 unsigned nr_free; 1023 1024 if (!p->dev) 1025 continue; 1026 if (shrink_pages == 0) 1027 break; 1028 /* Do it in round-robin fashion. */ 1029 if (++idx < pool_offset) 1030 continue; 1031 nr_free = shrink_pages; 1032 shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free); 1033 pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n", 1034 p->pool->dev_name, p->pool->name, current->pid, 1035 nr_free, shrink_pages); 1036 } 1037 mutex_unlock(&_manager->lock); 1038 /* return estimated number of unused pages in pool */ 1039 return ttm_dma_pool_get_num_unused_pages(); 1040} 1041 1042static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager) 1043{ 1044 manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink; 1045 manager->mm_shrink.seeks = 1; 1046 register_shrinker(&manager->mm_shrink); 1047} 1048 1049static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager) 1050{ 1051 unregister_shrinker(&manager->mm_shrink); 1052} 1053 1054int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) 1055{ 1056 int ret = -ENOMEM; 1057 1058 WARN_ON(_manager); 1059 1060 pr_info("Initializing DMA pool allocator\n"); 1061 1062 _manager = kzalloc(sizeof(*_manager), GFP_KERNEL); 1063 if (!_manager) 1064 goto err; 1065 1066 mutex_init(&_manager->lock); 1067 INIT_LIST_HEAD(&_manager->pools); 1068 1069 _manager->options.max_size = max_pages; 1070 _manager->options.small = SMALL_ALLOCATION; 1071 _manager->options.alloc_size = NUM_PAGES_TO_ALLOC; 1072 1073 /* This takes care of auto-freeing the _manager */ 1074 ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type, 1075 &glob->kobj, "dma_pool"); 1076 if (unlikely(ret != 0)) { 1077 kobject_put(&_manager->kobj); 1078 goto err; 1079 } 1080 ttm_dma_pool_mm_shrink_init(_manager); 1081 return 0; 1082err: 1083 return ret; 1084} 1085 1086void ttm_dma_page_alloc_fini(void) 1087{ 1088 struct device_pools *p, *t; 1089 1090 pr_info("Finalizing DMA pool allocator\n"); 1091 ttm_dma_pool_mm_shrink_fini(_manager); 1092 1093 list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) { 1094 dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name, 1095 current->pid); 1096 WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release, 1097 ttm_dma_pool_match, p->pool)); 1098 ttm_dma_free_pool(p->dev, p->pool->type); 1099 } 1100 kobject_put(&_manager->kobj); 1101 _manager = NULL; 1102} 1103 1104int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data) 1105{ 1106 struct device_pools *p; 1107 struct dma_pool *pool = NULL; 1108 char *h[] = {"pool", "refills", "pages freed", "inuse", "available", 1109 "name", "virt", "busaddr"}; 1110 1111 if (!_manager) { 1112 seq_printf(m, "No pool allocator running.\n"); 1113 return 0; 1114 } 1115 seq_printf(m, "%13s %12s %13s %8s %8s %8s\n", 1116 h[0], h[1], h[2], h[3], h[4], h[5]); 1117 mutex_lock(&_manager->lock); 1118 list_for_each_entry(p, &_manager->pools, pools) { 1119 struct device *dev = p->dev; 1120 if (!dev) 1121 continue; 1122 pool = p->pool; 1123 seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n", 1124 pool->name, pool->nrefills, 1125 pool->nfrees, pool->npages_in_use, 1126 pool->npages_free, 1127 pool->dev_name); 1128 } 1129 mutex_unlock(&_manager->lock); 1130 return 0; 1131} 1132EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs); 1133