1/* 2 * Copyright (C) 2008 Advanced Micro Devices, Inc. 3 * 4 * Author: Joerg Roedel <joerg.roedel@amd.com> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published 8 * by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20#include <linux/scatterlist.h> 21#include <linux/dma-mapping.h> 22#include <linux/stacktrace.h> 23#include <linux/dma-debug.h> 24#include <linux/spinlock.h> 25#include <linux/debugfs.h> 26#include <linux/uaccess.h> 27#include <linux/export.h> 28#include <linux/device.h> 29#include <linux/types.h> 30#include <linux/sched.h> 31#include <linux/ctype.h> 32#include <linux/list.h> 33#include <linux/slab.h> 34 35#include <asm/sections.h> 36 37#define HASH_SIZE 1024ULL 38#define HASH_FN_SHIFT 13 39#define HASH_FN_MASK (HASH_SIZE - 1) 40 41enum { 42 dma_debug_single, 43 dma_debug_page, 44 dma_debug_sg, 45 dma_debug_coherent, 46}; 47 48enum map_err_types { 49 MAP_ERR_CHECK_NOT_APPLICABLE, 50 MAP_ERR_NOT_CHECKED, 51 MAP_ERR_CHECKED, 52}; 53 54#define DMA_DEBUG_STACKTRACE_ENTRIES 5 55 56/** 57 * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping 58 * @list: node on pre-allocated free_entries list 59 * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent 60 * @type: single, page, sg, coherent 61 * @pfn: page frame of the start address 62 * @offset: offset of mapping relative to pfn 63 * @size: length of the mapping 64 * @direction: enum dma_data_direction 65 * @sg_call_ents: 'nents' from dma_map_sg 66 * @sg_mapped_ents: 'mapped_ents' from dma_map_sg 67 * @map_err_type: track whether dma_mapping_error() was checked 68 * @stacktrace: support backtraces when a violation is detected 69 */ 70struct dma_debug_entry { 71 struct list_head list; 72 struct device *dev; 73 int type; 74 unsigned long pfn; 75 size_t offset; 76 u64 dev_addr; 77 u64 size; 78 int direction; 79 int sg_call_ents; 80 int sg_mapped_ents; 81 enum map_err_types map_err_type; 82#ifdef CONFIG_STACKTRACE 83 struct stack_trace stacktrace; 84 unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES]; 85#endif 86}; 87 88typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *); 89 90struct hash_bucket { 91 struct list_head list; 92 spinlock_t lock; 93} ____cacheline_aligned_in_smp; 94 95/* Hash list to save the allocated dma addresses */ 96static struct hash_bucket dma_entry_hash[HASH_SIZE]; 97/* List of pre-allocated dma_debug_entry's */ 98static LIST_HEAD(free_entries); 99/* Lock for the list above */ 100static DEFINE_SPINLOCK(free_entries_lock); 101 102/* Global disable flag - will be set in case of an error */ 103static u32 global_disable __read_mostly; 104 105/* Early initialization disable flag, set at the end of dma_debug_init */ 106static bool dma_debug_initialized __read_mostly; 107 108static inline bool dma_debug_disabled(void) 109{ 110 return global_disable || !dma_debug_initialized; 111} 112 113/* Global error count */ 114static u32 error_count; 115 116/* Global error show enable*/ 117static u32 show_all_errors __read_mostly; 118/* Number of errors to show */ 119static u32 show_num_errors = 1; 120 121static u32 num_free_entries; 122static u32 min_free_entries; 123static u32 nr_total_entries; 124 125/* number of preallocated entries requested by kernel cmdline */ 126static u32 req_entries; 127 128/* debugfs dentry's for the stuff above */ 129static struct dentry *dma_debug_dent __read_mostly; 130static struct dentry *global_disable_dent __read_mostly; 131static struct dentry *error_count_dent __read_mostly; 132static struct dentry *show_all_errors_dent __read_mostly; 133static struct dentry *show_num_errors_dent __read_mostly; 134static struct dentry *num_free_entries_dent __read_mostly; 135static struct dentry *min_free_entries_dent __read_mostly; 136static struct dentry *filter_dent __read_mostly; 137 138/* per-driver filter related state */ 139 140#define NAME_MAX_LEN 64 141 142static char current_driver_name[NAME_MAX_LEN] __read_mostly; 143static struct device_driver *current_driver __read_mostly; 144 145static DEFINE_RWLOCK(driver_name_lock); 146 147static const char *const maperr2str[] = { 148 [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable", 149 [MAP_ERR_NOT_CHECKED] = "dma map error not checked", 150 [MAP_ERR_CHECKED] = "dma map error checked", 151}; 152 153static const char *type2name[4] = { "single", "page", 154 "scather-gather", "coherent" }; 155 156static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE", 157 "DMA_FROM_DEVICE", "DMA_NONE" }; 158 159/* 160 * The access to some variables in this macro is racy. We can't use atomic_t 161 * here because all these variables are exported to debugfs. Some of them even 162 * writeable. This is also the reason why a lock won't help much. But anyway, 163 * the races are no big deal. Here is why: 164 * 165 * error_count: the addition is racy, but the worst thing that can happen is 166 * that we don't count some errors 167 * show_num_errors: the subtraction is racy. Also no big deal because in 168 * worst case this will result in one warning more in the 169 * system log than the user configured. This variable is 170 * writeable via debugfs. 171 */ 172static inline void dump_entry_trace(struct dma_debug_entry *entry) 173{ 174#ifdef CONFIG_STACKTRACE 175 if (entry) { 176 pr_warning("Mapped at:\n"); 177 print_stack_trace(&entry->stacktrace, 0); 178 } 179#endif 180} 181 182static bool driver_filter(struct device *dev) 183{ 184 struct device_driver *drv; 185 unsigned long flags; 186 bool ret; 187 188 /* driver filter off */ 189 if (likely(!current_driver_name[0])) 190 return true; 191 192 /* driver filter on and initialized */ 193 if (current_driver && dev && dev->driver == current_driver) 194 return true; 195 196 /* driver filter on, but we can't filter on a NULL device... */ 197 if (!dev) 198 return false; 199 200 if (current_driver || !current_driver_name[0]) 201 return false; 202 203 /* driver filter on but not yet initialized */ 204 drv = dev->driver; 205 if (!drv) 206 return false; 207 208 /* lock to protect against change of current_driver_name */ 209 read_lock_irqsave(&driver_name_lock, flags); 210 211 ret = false; 212 if (drv->name && 213 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) { 214 current_driver = drv; 215 ret = true; 216 } 217 218 read_unlock_irqrestore(&driver_name_lock, flags); 219 220 return ret; 221} 222 223#define err_printk(dev, entry, format, arg...) do { \ 224 error_count += 1; \ 225 if (driver_filter(dev) && \ 226 (show_all_errors || show_num_errors > 0)) { \ 227 WARN(1, "%s %s: " format, \ 228 dev ? dev_driver_string(dev) : "NULL", \ 229 dev ? dev_name(dev) : "NULL", ## arg); \ 230 dump_entry_trace(entry); \ 231 } \ 232 if (!show_all_errors && show_num_errors > 0) \ 233 show_num_errors -= 1; \ 234 } while (0); 235 236/* 237 * Hash related functions 238 * 239 * Every DMA-API request is saved into a struct dma_debug_entry. To 240 * have quick access to these structs they are stored into a hash. 241 */ 242static int hash_fn(struct dma_debug_entry *entry) 243{ 244 /* 245 * Hash function is based on the dma address. 246 * We use bits 20-27 here as the index into the hash 247 */ 248 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK; 249} 250 251/* 252 * Request exclusive access to a hash bucket for a given dma_debug_entry. 253 */ 254static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry, 255 unsigned long *flags) 256{ 257 int idx = hash_fn(entry); 258 unsigned long __flags; 259 260 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags); 261 *flags = __flags; 262 return &dma_entry_hash[idx]; 263} 264 265/* 266 * Give up exclusive access to the hash bucket 267 */ 268static void put_hash_bucket(struct hash_bucket *bucket, 269 unsigned long *flags) 270{ 271 unsigned long __flags = *flags; 272 273 spin_unlock_irqrestore(&bucket->lock, __flags); 274} 275 276static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b) 277{ 278 return ((a->dev_addr == b->dev_addr) && 279 (a->dev == b->dev)) ? true : false; 280} 281 282static bool containing_match(struct dma_debug_entry *a, 283 struct dma_debug_entry *b) 284{ 285 if (a->dev != b->dev) 286 return false; 287 288 if ((b->dev_addr <= a->dev_addr) && 289 ((b->dev_addr + b->size) >= (a->dev_addr + a->size))) 290 return true; 291 292 return false; 293} 294 295/* 296 * Search a given entry in the hash bucket list 297 */ 298static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket, 299 struct dma_debug_entry *ref, 300 match_fn match) 301{ 302 struct dma_debug_entry *entry, *ret = NULL; 303 int matches = 0, match_lvl, last_lvl = -1; 304 305 list_for_each_entry(entry, &bucket->list, list) { 306 if (!match(ref, entry)) 307 continue; 308 309 /* 310 * Some drivers map the same physical address multiple 311 * times. Without a hardware IOMMU this results in the 312 * same device addresses being put into the dma-debug 313 * hash multiple times too. This can result in false 314 * positives being reported. Therefore we implement a 315 * best-fit algorithm here which returns the entry from 316 * the hash which fits best to the reference value 317 * instead of the first-fit. 318 */ 319 matches += 1; 320 match_lvl = 0; 321 entry->size == ref->size ? ++match_lvl : 0; 322 entry->type == ref->type ? ++match_lvl : 0; 323 entry->direction == ref->direction ? ++match_lvl : 0; 324 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0; 325 326 if (match_lvl == 4) { 327 /* perfect-fit - return the result */ 328 return entry; 329 } else if (match_lvl > last_lvl) { 330 /* 331 * We found an entry that fits better then the 332 * previous one or it is the 1st match. 333 */ 334 last_lvl = match_lvl; 335 ret = entry; 336 } 337 } 338 339 /* 340 * If we have multiple matches but no perfect-fit, just return 341 * NULL. 342 */ 343 ret = (matches == 1) ? ret : NULL; 344 345 return ret; 346} 347 348static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket, 349 struct dma_debug_entry *ref) 350{ 351 return __hash_bucket_find(bucket, ref, exact_match); 352} 353 354static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket, 355 struct dma_debug_entry *ref, 356 unsigned long *flags) 357{ 358 359 unsigned int max_range = dma_get_max_seg_size(ref->dev); 360 struct dma_debug_entry *entry, index = *ref; 361 unsigned int range = 0; 362 363 while (range <= max_range) { 364 entry = __hash_bucket_find(*bucket, ref, containing_match); 365 366 if (entry) 367 return entry; 368 369 /* 370 * Nothing found, go back a hash bucket 371 */ 372 put_hash_bucket(*bucket, flags); 373 range += (1 << HASH_FN_SHIFT); 374 index.dev_addr -= (1 << HASH_FN_SHIFT); 375 *bucket = get_hash_bucket(&index, flags); 376 } 377 378 return NULL; 379} 380 381/* 382 * Add an entry to a hash bucket 383 */ 384static void hash_bucket_add(struct hash_bucket *bucket, 385 struct dma_debug_entry *entry) 386{ 387 list_add_tail(&entry->list, &bucket->list); 388} 389 390/* 391 * Remove entry from a hash bucket list 392 */ 393static void hash_bucket_del(struct dma_debug_entry *entry) 394{ 395 list_del(&entry->list); 396} 397 398static unsigned long long phys_addr(struct dma_debug_entry *entry) 399{ 400 return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset; 401} 402 403/* 404 * Dump mapping entries for debugging purposes 405 */ 406void debug_dma_dump_mappings(struct device *dev) 407{ 408 int idx; 409 410 for (idx = 0; idx < HASH_SIZE; idx++) { 411 struct hash_bucket *bucket = &dma_entry_hash[idx]; 412 struct dma_debug_entry *entry; 413 unsigned long flags; 414 415 spin_lock_irqsave(&bucket->lock, flags); 416 417 list_for_each_entry(entry, &bucket->list, list) { 418 if (!dev || dev == entry->dev) { 419 dev_info(entry->dev, 420 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n", 421 type2name[entry->type], idx, 422 phys_addr(entry), entry->pfn, 423 entry->dev_addr, entry->size, 424 dir2name[entry->direction], 425 maperr2str[entry->map_err_type]); 426 } 427 } 428 429 spin_unlock_irqrestore(&bucket->lock, flags); 430 } 431} 432EXPORT_SYMBOL(debug_dma_dump_mappings); 433 434/* 435 * For each mapping (initial cacheline in the case of 436 * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a 437 * scatterlist, or the cacheline specified in dma_map_single) insert 438 * into this tree using the cacheline as the key. At 439 * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If 440 * the entry already exists at insertion time add a tag as a reference 441 * count for the overlapping mappings. For now, the overlap tracking 442 * just ensures that 'unmaps' balance 'maps' before marking the 443 * cacheline idle, but we should also be flagging overlaps as an API 444 * violation. 445 * 446 * Memory usage is mostly constrained by the maximum number of available 447 * dma-debug entries in that we need a free dma_debug_entry before 448 * inserting into the tree. In the case of dma_map_page and 449 * dma_alloc_coherent there is only one dma_debug_entry and one 450 * dma_active_cacheline entry to track per event. dma_map_sg(), on the 451 * other hand, consumes a single dma_debug_entry, but inserts 'nents' 452 * entries into the tree. 453 * 454 * At any time debug_dma_assert_idle() can be called to trigger a 455 * warning if any cachelines in the given page are in the active set. 456 */ 457static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT); 458static DEFINE_SPINLOCK(radix_lock); 459#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1) 460#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT) 461#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT) 462 463static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry) 464{ 465 return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) + 466 (entry->offset >> L1_CACHE_SHIFT); 467} 468 469static int active_cacheline_read_overlap(phys_addr_t cln) 470{ 471 int overlap = 0, i; 472 473 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--) 474 if (radix_tree_tag_get(&dma_active_cacheline, cln, i)) 475 overlap |= 1 << i; 476 return overlap; 477} 478 479static int active_cacheline_set_overlap(phys_addr_t cln, int overlap) 480{ 481 int i; 482 483 if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0) 484 return overlap; 485 486 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--) 487 if (overlap & 1 << i) 488 radix_tree_tag_set(&dma_active_cacheline, cln, i); 489 else 490 radix_tree_tag_clear(&dma_active_cacheline, cln, i); 491 492 return overlap; 493} 494 495static void active_cacheline_inc_overlap(phys_addr_t cln) 496{ 497 int overlap = active_cacheline_read_overlap(cln); 498 499 overlap = active_cacheline_set_overlap(cln, ++overlap); 500 501 /* If we overflowed the overlap counter then we're potentially 502 * leaking dma-mappings. Otherwise, if maps and unmaps are 503 * balanced then this overflow may cause false negatives in 504 * debug_dma_assert_idle() as the cacheline may be marked idle 505 * prematurely. 506 */ 507 WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP, 508 "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n", 509 ACTIVE_CACHELINE_MAX_OVERLAP, &cln); 510} 511 512static int active_cacheline_dec_overlap(phys_addr_t cln) 513{ 514 int overlap = active_cacheline_read_overlap(cln); 515 516 return active_cacheline_set_overlap(cln, --overlap); 517} 518 519static int active_cacheline_insert(struct dma_debug_entry *entry) 520{ 521 phys_addr_t cln = to_cacheline_number(entry); 522 unsigned long flags; 523 int rc; 524 525 /* If the device is not writing memory then we don't have any 526 * concerns about the cpu consuming stale data. This mitigates 527 * legitimate usages of overlapping mappings. 528 */ 529 if (entry->direction == DMA_TO_DEVICE) 530 return 0; 531 532 spin_lock_irqsave(&radix_lock, flags); 533 rc = radix_tree_insert(&dma_active_cacheline, cln, entry); 534 if (rc == -EEXIST) 535 active_cacheline_inc_overlap(cln); 536 spin_unlock_irqrestore(&radix_lock, flags); 537 538 return rc; 539} 540 541static void active_cacheline_remove(struct dma_debug_entry *entry) 542{ 543 phys_addr_t cln = to_cacheline_number(entry); 544 unsigned long flags; 545 546 /* ...mirror the insert case */ 547 if (entry->direction == DMA_TO_DEVICE) 548 return; 549 550 spin_lock_irqsave(&radix_lock, flags); 551 /* since we are counting overlaps the final put of the 552 * cacheline will occur when the overlap count is 0. 553 * active_cacheline_dec_overlap() returns -1 in that case 554 */ 555 if (active_cacheline_dec_overlap(cln) < 0) 556 radix_tree_delete(&dma_active_cacheline, cln); 557 spin_unlock_irqrestore(&radix_lock, flags); 558} 559 560/** 561 * debug_dma_assert_idle() - assert that a page is not undergoing dma 562 * @page: page to lookup in the dma_active_cacheline tree 563 * 564 * Place a call to this routine in cases where the cpu touching the page 565 * before the dma completes (page is dma_unmapped) will lead to data 566 * corruption. 567 */ 568void debug_dma_assert_idle(struct page *page) 569{ 570 static struct dma_debug_entry *ents[CACHELINES_PER_PAGE]; 571 struct dma_debug_entry *entry = NULL; 572 void **results = (void **) &ents; 573 unsigned int nents, i; 574 unsigned long flags; 575 phys_addr_t cln; 576 577 if (dma_debug_disabled()) 578 return; 579 580 if (!page) 581 return; 582 583 cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT; 584 spin_lock_irqsave(&radix_lock, flags); 585 nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln, 586 CACHELINES_PER_PAGE); 587 for (i = 0; i < nents; i++) { 588 phys_addr_t ent_cln = to_cacheline_number(ents[i]); 589 590 if (ent_cln == cln) { 591 entry = ents[i]; 592 break; 593 } else if (ent_cln >= cln + CACHELINES_PER_PAGE) 594 break; 595 } 596 spin_unlock_irqrestore(&radix_lock, flags); 597 598 if (!entry) 599 return; 600 601 cln = to_cacheline_number(entry); 602 err_printk(entry->dev, entry, 603 "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n", 604 &cln); 605} 606 607/* 608 * Wrapper function for adding an entry to the hash. 609 * This function takes care of locking itself. 610 */ 611static void add_dma_entry(struct dma_debug_entry *entry) 612{ 613 struct hash_bucket *bucket; 614 unsigned long flags; 615 int rc; 616 617 bucket = get_hash_bucket(entry, &flags); 618 hash_bucket_add(bucket, entry); 619 put_hash_bucket(bucket, &flags); 620 621 rc = active_cacheline_insert(entry); 622 if (rc == -ENOMEM) { 623 pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n"); 624 global_disable = true; 625 } 626 627 /* TODO: report -EEXIST errors here as overlapping mappings are 628 * not supported by the DMA API 629 */ 630} 631 632static struct dma_debug_entry *__dma_entry_alloc(void) 633{ 634 struct dma_debug_entry *entry; 635 636 entry = list_entry(free_entries.next, struct dma_debug_entry, list); 637 list_del(&entry->list); 638 memset(entry, 0, sizeof(*entry)); 639 640 num_free_entries -= 1; 641 if (num_free_entries < min_free_entries) 642 min_free_entries = num_free_entries; 643 644 return entry; 645} 646 647/* struct dma_entry allocator 648 * 649 * The next two functions implement the allocator for 650 * struct dma_debug_entries. 651 */ 652static struct dma_debug_entry *dma_entry_alloc(void) 653{ 654 struct dma_debug_entry *entry; 655 unsigned long flags; 656 657 spin_lock_irqsave(&free_entries_lock, flags); 658 659 if (list_empty(&free_entries)) { 660 global_disable = true; 661 spin_unlock_irqrestore(&free_entries_lock, flags); 662 pr_err("DMA-API: debugging out of memory - disabling\n"); 663 return NULL; 664 } 665 666 entry = __dma_entry_alloc(); 667 668 spin_unlock_irqrestore(&free_entries_lock, flags); 669 670#ifdef CONFIG_STACKTRACE 671 entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES; 672 entry->stacktrace.entries = entry->st_entries; 673 entry->stacktrace.skip = 2; 674 save_stack_trace(&entry->stacktrace); 675#endif 676 677 return entry; 678} 679 680static void dma_entry_free(struct dma_debug_entry *entry) 681{ 682 unsigned long flags; 683 684 active_cacheline_remove(entry); 685 686 /* 687 * add to beginning of the list - this way the entries are 688 * more likely cache hot when they are reallocated. 689 */ 690 spin_lock_irqsave(&free_entries_lock, flags); 691 list_add(&entry->list, &free_entries); 692 num_free_entries += 1; 693 spin_unlock_irqrestore(&free_entries_lock, flags); 694} 695 696int dma_debug_resize_entries(u32 num_entries) 697{ 698 int i, delta, ret = 0; 699 unsigned long flags; 700 struct dma_debug_entry *entry; 701 LIST_HEAD(tmp); 702 703 spin_lock_irqsave(&free_entries_lock, flags); 704 705 if (nr_total_entries < num_entries) { 706 delta = num_entries - nr_total_entries; 707 708 spin_unlock_irqrestore(&free_entries_lock, flags); 709 710 for (i = 0; i < delta; i++) { 711 entry = kzalloc(sizeof(*entry), GFP_KERNEL); 712 if (!entry) 713 break; 714 715 list_add_tail(&entry->list, &tmp); 716 } 717 718 spin_lock_irqsave(&free_entries_lock, flags); 719 720 list_splice(&tmp, &free_entries); 721 nr_total_entries += i; 722 num_free_entries += i; 723 } else { 724 delta = nr_total_entries - num_entries; 725 726 for (i = 0; i < delta && !list_empty(&free_entries); i++) { 727 entry = __dma_entry_alloc(); 728 kfree(entry); 729 } 730 731 nr_total_entries -= i; 732 } 733 734 if (nr_total_entries != num_entries) 735 ret = 1; 736 737 spin_unlock_irqrestore(&free_entries_lock, flags); 738 739 return ret; 740} 741EXPORT_SYMBOL(dma_debug_resize_entries); 742 743/* 744 * DMA-API debugging init code 745 * 746 * The init code does two things: 747 * 1. Initialize core data structures 748 * 2. Preallocate a given number of dma_debug_entry structs 749 */ 750 751static int prealloc_memory(u32 num_entries) 752{ 753 struct dma_debug_entry *entry, *next_entry; 754 int i; 755 756 for (i = 0; i < num_entries; ++i) { 757 entry = kzalloc(sizeof(*entry), GFP_KERNEL); 758 if (!entry) 759 goto out_err; 760 761 list_add_tail(&entry->list, &free_entries); 762 } 763 764 num_free_entries = num_entries; 765 min_free_entries = num_entries; 766 767 pr_info("DMA-API: preallocated %d debug entries\n", num_entries); 768 769 return 0; 770 771out_err: 772 773 list_for_each_entry_safe(entry, next_entry, &free_entries, list) { 774 list_del(&entry->list); 775 kfree(entry); 776 } 777 778 return -ENOMEM; 779} 780 781static ssize_t filter_read(struct file *file, char __user *user_buf, 782 size_t count, loff_t *ppos) 783{ 784 char buf[NAME_MAX_LEN + 1]; 785 unsigned long flags; 786 int len; 787 788 if (!current_driver_name[0]) 789 return 0; 790 791 /* 792 * We can't copy to userspace directly because current_driver_name can 793 * only be read under the driver_name_lock with irqs disabled. So 794 * create a temporary copy first. 795 */ 796 read_lock_irqsave(&driver_name_lock, flags); 797 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name); 798 read_unlock_irqrestore(&driver_name_lock, flags); 799 800 return simple_read_from_buffer(user_buf, count, ppos, buf, len); 801} 802 803static ssize_t filter_write(struct file *file, const char __user *userbuf, 804 size_t count, loff_t *ppos) 805{ 806 char buf[NAME_MAX_LEN]; 807 unsigned long flags; 808 size_t len; 809 int i; 810 811 /* 812 * We can't copy from userspace directly. Access to 813 * current_driver_name is protected with a write_lock with irqs 814 * disabled. Since copy_from_user can fault and may sleep we 815 * need to copy to temporary buffer first 816 */ 817 len = min(count, (size_t)(NAME_MAX_LEN - 1)); 818 if (copy_from_user(buf, userbuf, len)) 819 return -EFAULT; 820 821 buf[len] = 0; 822 823 write_lock_irqsave(&driver_name_lock, flags); 824 825 /* 826 * Now handle the string we got from userspace very carefully. 827 * The rules are: 828 * - only use the first token we got 829 * - token delimiter is everything looking like a space 830 * character (' ', '\n', '\t' ...) 831 * 832 */ 833 if (!isalnum(buf[0])) { 834 /* 835 * If the first character userspace gave us is not 836 * alphanumerical then assume the filter should be 837 * switched off. 838 */ 839 if (current_driver_name[0]) 840 pr_info("DMA-API: switching off dma-debug driver filter\n"); 841 current_driver_name[0] = 0; 842 current_driver = NULL; 843 goto out_unlock; 844 } 845 846 /* 847 * Now parse out the first token and use it as the name for the 848 * driver to filter for. 849 */ 850 for (i = 0; i < NAME_MAX_LEN - 1; ++i) { 851 current_driver_name[i] = buf[i]; 852 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0) 853 break; 854 } 855 current_driver_name[i] = 0; 856 current_driver = NULL; 857 858 pr_info("DMA-API: enable driver filter for driver [%s]\n", 859 current_driver_name); 860 861out_unlock: 862 write_unlock_irqrestore(&driver_name_lock, flags); 863 864 return count; 865} 866 867static const struct file_operations filter_fops = { 868 .read = filter_read, 869 .write = filter_write, 870 .llseek = default_llseek, 871}; 872 873static int dma_debug_fs_init(void) 874{ 875 dma_debug_dent = debugfs_create_dir("dma-api", NULL); 876 if (!dma_debug_dent) { 877 pr_err("DMA-API: can not create debugfs directory\n"); 878 return -ENOMEM; 879 } 880 881 global_disable_dent = debugfs_create_bool("disabled", 0444, 882 dma_debug_dent, 883 &global_disable); 884 if (!global_disable_dent) 885 goto out_err; 886 887 error_count_dent = debugfs_create_u32("error_count", 0444, 888 dma_debug_dent, &error_count); 889 if (!error_count_dent) 890 goto out_err; 891 892 show_all_errors_dent = debugfs_create_u32("all_errors", 0644, 893 dma_debug_dent, 894 &show_all_errors); 895 if (!show_all_errors_dent) 896 goto out_err; 897 898 show_num_errors_dent = debugfs_create_u32("num_errors", 0644, 899 dma_debug_dent, 900 &show_num_errors); 901 if (!show_num_errors_dent) 902 goto out_err; 903 904 num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444, 905 dma_debug_dent, 906 &num_free_entries); 907 if (!num_free_entries_dent) 908 goto out_err; 909 910 min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444, 911 dma_debug_dent, 912 &min_free_entries); 913 if (!min_free_entries_dent) 914 goto out_err; 915 916 filter_dent = debugfs_create_file("driver_filter", 0644, 917 dma_debug_dent, NULL, &filter_fops); 918 if (!filter_dent) 919 goto out_err; 920 921 return 0; 922 923out_err: 924 debugfs_remove_recursive(dma_debug_dent); 925 926 return -ENOMEM; 927} 928 929static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry) 930{ 931 struct dma_debug_entry *entry; 932 unsigned long flags; 933 int count = 0, i; 934 935 local_irq_save(flags); 936 937 for (i = 0; i < HASH_SIZE; ++i) { 938 spin_lock(&dma_entry_hash[i].lock); 939 list_for_each_entry(entry, &dma_entry_hash[i].list, list) { 940 if (entry->dev == dev) { 941 count += 1; 942 *out_entry = entry; 943 } 944 } 945 spin_unlock(&dma_entry_hash[i].lock); 946 } 947 948 local_irq_restore(flags); 949 950 return count; 951} 952 953static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data) 954{ 955 struct device *dev = data; 956 struct dma_debug_entry *uninitialized_var(entry); 957 int count; 958 959 if (dma_debug_disabled()) 960 return 0; 961 962 switch (action) { 963 case BUS_NOTIFY_UNBOUND_DRIVER: 964 count = device_dma_allocations(dev, &entry); 965 if (count == 0) 966 break; 967 err_printk(dev, entry, "DMA-API: device driver has pending " 968 "DMA allocations while released from device " 969 "[count=%d]\n" 970 "One of leaked entries details: " 971 "[device address=0x%016llx] [size=%llu bytes] " 972 "[mapped with %s] [mapped as %s]\n", 973 count, entry->dev_addr, entry->size, 974 dir2name[entry->direction], type2name[entry->type]); 975 break; 976 default: 977 break; 978 } 979 980 return 0; 981} 982 983void dma_debug_add_bus(struct bus_type *bus) 984{ 985 struct notifier_block *nb; 986 987 if (dma_debug_disabled()) 988 return; 989 990 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL); 991 if (nb == NULL) { 992 pr_err("dma_debug_add_bus: out of memory\n"); 993 return; 994 } 995 996 nb->notifier_call = dma_debug_device_change; 997 998 bus_register_notifier(bus, nb); 999} 1000 1001/* 1002 * Let the architectures decide how many entries should be preallocated. 1003 */ 1004void dma_debug_init(u32 num_entries) 1005{ 1006 int i; 1007 1008 /* Do not use dma_debug_initialized here, since we really want to be 1009 * called to set dma_debug_initialized 1010 */ 1011 if (global_disable) 1012 return; 1013 1014 for (i = 0; i < HASH_SIZE; ++i) { 1015 INIT_LIST_HEAD(&dma_entry_hash[i].list); 1016 spin_lock_init(&dma_entry_hash[i].lock); 1017 } 1018 1019 if (dma_debug_fs_init() != 0) { 1020 pr_err("DMA-API: error creating debugfs entries - disabling\n"); 1021 global_disable = true; 1022 1023 return; 1024 } 1025 1026 if (req_entries) 1027 num_entries = req_entries; 1028 1029 if (prealloc_memory(num_entries) != 0) { 1030 pr_err("DMA-API: debugging out of memory error - disabled\n"); 1031 global_disable = true; 1032 1033 return; 1034 } 1035 1036 nr_total_entries = num_free_entries; 1037 1038 dma_debug_initialized = true; 1039 1040 pr_info("DMA-API: debugging enabled by kernel config\n"); 1041} 1042 1043static __init int dma_debug_cmdline(char *str) 1044{ 1045 if (!str) 1046 return -EINVAL; 1047 1048 if (strncmp(str, "off", 3) == 0) { 1049 pr_info("DMA-API: debugging disabled on kernel command line\n"); 1050 global_disable = true; 1051 } 1052 1053 return 0; 1054} 1055 1056static __init int dma_debug_entries_cmdline(char *str) 1057{ 1058 int res; 1059 1060 if (!str) 1061 return -EINVAL; 1062 1063 res = get_option(&str, &req_entries); 1064 1065 if (!res) 1066 req_entries = 0; 1067 1068 return 0; 1069} 1070 1071__setup("dma_debug=", dma_debug_cmdline); 1072__setup("dma_debug_entries=", dma_debug_entries_cmdline); 1073 1074static void check_unmap(struct dma_debug_entry *ref) 1075{ 1076 struct dma_debug_entry *entry; 1077 struct hash_bucket *bucket; 1078 unsigned long flags; 1079 1080 bucket = get_hash_bucket(ref, &flags); 1081 entry = bucket_find_exact(bucket, ref); 1082 1083 if (!entry) { 1084 /* must drop lock before calling dma_mapping_error */ 1085 put_hash_bucket(bucket, &flags); 1086 1087 if (dma_mapping_error(ref->dev, ref->dev_addr)) { 1088 err_printk(ref->dev, NULL, 1089 "DMA-API: device driver tries to free an " 1090 "invalid DMA memory address\n"); 1091 } else { 1092 err_printk(ref->dev, NULL, 1093 "DMA-API: device driver tries to free DMA " 1094 "memory it has not allocated [device " 1095 "address=0x%016llx] [size=%llu bytes]\n", 1096 ref->dev_addr, ref->size); 1097 } 1098 return; 1099 } 1100 1101 if (ref->size != entry->size) { 1102 err_printk(ref->dev, entry, "DMA-API: device driver frees " 1103 "DMA memory with different size " 1104 "[device address=0x%016llx] [map size=%llu bytes] " 1105 "[unmap size=%llu bytes]\n", 1106 ref->dev_addr, entry->size, ref->size); 1107 } 1108 1109 if (ref->type != entry->type) { 1110 err_printk(ref->dev, entry, "DMA-API: device driver frees " 1111 "DMA memory with wrong function " 1112 "[device address=0x%016llx] [size=%llu bytes] " 1113 "[mapped as %s] [unmapped as %s]\n", 1114 ref->dev_addr, ref->size, 1115 type2name[entry->type], type2name[ref->type]); 1116 } else if ((entry->type == dma_debug_coherent) && 1117 (phys_addr(ref) != phys_addr(entry))) { 1118 err_printk(ref->dev, entry, "DMA-API: device driver frees " 1119 "DMA memory with different CPU address " 1120 "[device address=0x%016llx] [size=%llu bytes] " 1121 "[cpu alloc address=0x%016llx] " 1122 "[cpu free address=0x%016llx]", 1123 ref->dev_addr, ref->size, 1124 phys_addr(entry), 1125 phys_addr(ref)); 1126 } 1127 1128 if (ref->sg_call_ents && ref->type == dma_debug_sg && 1129 ref->sg_call_ents != entry->sg_call_ents) { 1130 err_printk(ref->dev, entry, "DMA-API: device driver frees " 1131 "DMA sg list with different entry count " 1132 "[map count=%d] [unmap count=%d]\n", 1133 entry->sg_call_ents, ref->sg_call_ents); 1134 } 1135 1136 /* 1137 * This may be no bug in reality - but most implementations of the 1138 * DMA API don't handle this properly, so check for it here 1139 */ 1140 if (ref->direction != entry->direction) { 1141 err_printk(ref->dev, entry, "DMA-API: device driver frees " 1142 "DMA memory with different direction " 1143 "[device address=0x%016llx] [size=%llu bytes] " 1144 "[mapped with %s] [unmapped with %s]\n", 1145 ref->dev_addr, ref->size, 1146 dir2name[entry->direction], 1147 dir2name[ref->direction]); 1148 } 1149 1150 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) { 1151 err_printk(ref->dev, entry, 1152 "DMA-API: device driver failed to check map error" 1153 "[device address=0x%016llx] [size=%llu bytes] " 1154 "[mapped as %s]", 1155 ref->dev_addr, ref->size, 1156 type2name[entry->type]); 1157 } 1158 1159 hash_bucket_del(entry); 1160 dma_entry_free(entry); 1161 1162 put_hash_bucket(bucket, &flags); 1163} 1164 1165static void check_for_stack(struct device *dev, void *addr) 1166{ 1167 if (object_is_on_stack(addr)) 1168 err_printk(dev, NULL, "DMA-API: device driver maps memory from " 1169 "stack [addr=%p]\n", addr); 1170} 1171 1172static inline bool overlap(void *addr, unsigned long len, void *start, void *end) 1173{ 1174 unsigned long a1 = (unsigned long)addr; 1175 unsigned long b1 = a1 + len; 1176 unsigned long a2 = (unsigned long)start; 1177 unsigned long b2 = (unsigned long)end; 1178 1179 return !(b1 <= a2 || a1 >= b2); 1180} 1181 1182static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len) 1183{ 1184 if (overlap(addr, len, _stext, _etext) || 1185 overlap(addr, len, __start_rodata, __end_rodata)) 1186 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len); 1187} 1188 1189static void check_sync(struct device *dev, 1190 struct dma_debug_entry *ref, 1191 bool to_cpu) 1192{ 1193 struct dma_debug_entry *entry; 1194 struct hash_bucket *bucket; 1195 unsigned long flags; 1196 1197 bucket = get_hash_bucket(ref, &flags); 1198 1199 entry = bucket_find_contain(&bucket, ref, &flags); 1200 1201 if (!entry) { 1202 err_printk(dev, NULL, "DMA-API: device driver tries " 1203 "to sync DMA memory it has not allocated " 1204 "[device address=0x%016llx] [size=%llu bytes]\n", 1205 (unsigned long long)ref->dev_addr, ref->size); 1206 goto out; 1207 } 1208 1209 if (ref->size > entry->size) { 1210 err_printk(dev, entry, "DMA-API: device driver syncs" 1211 " DMA memory outside allocated range " 1212 "[device address=0x%016llx] " 1213 "[allocation size=%llu bytes] " 1214 "[sync offset+size=%llu]\n", 1215 entry->dev_addr, entry->size, 1216 ref->size); 1217 } 1218 1219 if (entry->direction == DMA_BIDIRECTIONAL) 1220 goto out; 1221 1222 if (ref->direction != entry->direction) { 1223 err_printk(dev, entry, "DMA-API: device driver syncs " 1224 "DMA memory with different direction " 1225 "[device address=0x%016llx] [size=%llu bytes] " 1226 "[mapped with %s] [synced with %s]\n", 1227 (unsigned long long)ref->dev_addr, entry->size, 1228 dir2name[entry->direction], 1229 dir2name[ref->direction]); 1230 } 1231 1232 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) && 1233 !(ref->direction == DMA_TO_DEVICE)) 1234 err_printk(dev, entry, "DMA-API: device driver syncs " 1235 "device read-only DMA memory for cpu " 1236 "[device address=0x%016llx] [size=%llu bytes] " 1237 "[mapped with %s] [synced with %s]\n", 1238 (unsigned long long)ref->dev_addr, entry->size, 1239 dir2name[entry->direction], 1240 dir2name[ref->direction]); 1241 1242 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) && 1243 !(ref->direction == DMA_FROM_DEVICE)) 1244 err_printk(dev, entry, "DMA-API: device driver syncs " 1245 "device write-only DMA memory to device " 1246 "[device address=0x%016llx] [size=%llu bytes] " 1247 "[mapped with %s] [synced with %s]\n", 1248 (unsigned long long)ref->dev_addr, entry->size, 1249 dir2name[entry->direction], 1250 dir2name[ref->direction]); 1251 1252out: 1253 put_hash_bucket(bucket, &flags); 1254} 1255 1256void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, 1257 size_t size, int direction, dma_addr_t dma_addr, 1258 bool map_single) 1259{ 1260 struct dma_debug_entry *entry; 1261 1262 if (unlikely(dma_debug_disabled())) 1263 return; 1264 1265 if (dma_mapping_error(dev, dma_addr)) 1266 return; 1267 1268 entry = dma_entry_alloc(); 1269 if (!entry) 1270 return; 1271 1272 entry->dev = dev; 1273 entry->type = dma_debug_page; 1274 entry->pfn = page_to_pfn(page); 1275 entry->offset = offset, 1276 entry->dev_addr = dma_addr; 1277 entry->size = size; 1278 entry->direction = direction; 1279 entry->map_err_type = MAP_ERR_NOT_CHECKED; 1280 1281 if (map_single) 1282 entry->type = dma_debug_single; 1283 1284 if (!PageHighMem(page)) { 1285 void *addr = page_address(page) + offset; 1286 1287 check_for_stack(dev, addr); 1288 check_for_illegal_area(dev, addr, size); 1289 } 1290 1291 add_dma_entry(entry); 1292} 1293EXPORT_SYMBOL(debug_dma_map_page); 1294 1295void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) 1296{ 1297 struct dma_debug_entry ref; 1298 struct dma_debug_entry *entry; 1299 struct hash_bucket *bucket; 1300 unsigned long flags; 1301 1302 if (unlikely(dma_debug_disabled())) 1303 return; 1304 1305 ref.dev = dev; 1306 ref.dev_addr = dma_addr; 1307 bucket = get_hash_bucket(&ref, &flags); 1308 1309 list_for_each_entry(entry, &bucket->list, list) { 1310 if (!exact_match(&ref, entry)) 1311 continue; 1312 1313 /* 1314 * The same physical address can be mapped multiple 1315 * times. Without a hardware IOMMU this results in the 1316 * same device addresses being put into the dma-debug 1317 * hash multiple times too. This can result in false 1318 * positives being reported. Therefore we implement a 1319 * best-fit algorithm here which updates the first entry 1320 * from the hash which fits the reference value and is 1321 * not currently listed as being checked. 1322 */ 1323 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) { 1324 entry->map_err_type = MAP_ERR_CHECKED; 1325 break; 1326 } 1327 } 1328 1329 put_hash_bucket(bucket, &flags); 1330} 1331EXPORT_SYMBOL(debug_dma_mapping_error); 1332 1333void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, 1334 size_t size, int direction, bool map_single) 1335{ 1336 struct dma_debug_entry ref = { 1337 .type = dma_debug_page, 1338 .dev = dev, 1339 .dev_addr = addr, 1340 .size = size, 1341 .direction = direction, 1342 }; 1343 1344 if (unlikely(dma_debug_disabled())) 1345 return; 1346 1347 if (map_single) 1348 ref.type = dma_debug_single; 1349 1350 check_unmap(&ref); 1351} 1352EXPORT_SYMBOL(debug_dma_unmap_page); 1353 1354void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, 1355 int nents, int mapped_ents, int direction) 1356{ 1357 struct dma_debug_entry *entry; 1358 struct scatterlist *s; 1359 int i; 1360 1361 if (unlikely(dma_debug_disabled())) 1362 return; 1363 1364 for_each_sg(sg, s, mapped_ents, i) { 1365 entry = dma_entry_alloc(); 1366 if (!entry) 1367 return; 1368 1369 entry->type = dma_debug_sg; 1370 entry->dev = dev; 1371 entry->pfn = page_to_pfn(sg_page(s)); 1372 entry->offset = s->offset, 1373 entry->size = sg_dma_len(s); 1374 entry->dev_addr = sg_dma_address(s); 1375 entry->direction = direction; 1376 entry->sg_call_ents = nents; 1377 entry->sg_mapped_ents = mapped_ents; 1378 1379 if (!PageHighMem(sg_page(s))) { 1380 check_for_stack(dev, sg_virt(s)); 1381 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s)); 1382 } 1383 1384 add_dma_entry(entry); 1385 } 1386} 1387EXPORT_SYMBOL(debug_dma_map_sg); 1388 1389static int get_nr_mapped_entries(struct device *dev, 1390 struct dma_debug_entry *ref) 1391{ 1392 struct dma_debug_entry *entry; 1393 struct hash_bucket *bucket; 1394 unsigned long flags; 1395 int mapped_ents; 1396 1397 bucket = get_hash_bucket(ref, &flags); 1398 entry = bucket_find_exact(bucket, ref); 1399 mapped_ents = 0; 1400 1401 if (entry) 1402 mapped_ents = entry->sg_mapped_ents; 1403 put_hash_bucket(bucket, &flags); 1404 1405 return mapped_ents; 1406} 1407 1408void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, 1409 int nelems, int dir) 1410{ 1411 struct scatterlist *s; 1412 int mapped_ents = 0, i; 1413 1414 if (unlikely(dma_debug_disabled())) 1415 return; 1416 1417 for_each_sg(sglist, s, nelems, i) { 1418 1419 struct dma_debug_entry ref = { 1420 .type = dma_debug_sg, 1421 .dev = dev, 1422 .pfn = page_to_pfn(sg_page(s)), 1423 .offset = s->offset, 1424 .dev_addr = sg_dma_address(s), 1425 .size = sg_dma_len(s), 1426 .direction = dir, 1427 .sg_call_ents = nelems, 1428 }; 1429 1430 if (mapped_ents && i >= mapped_ents) 1431 break; 1432 1433 if (!i) 1434 mapped_ents = get_nr_mapped_entries(dev, &ref); 1435 1436 check_unmap(&ref); 1437 } 1438} 1439EXPORT_SYMBOL(debug_dma_unmap_sg); 1440 1441void debug_dma_alloc_coherent(struct device *dev, size_t size, 1442 dma_addr_t dma_addr, void *virt) 1443{ 1444 struct dma_debug_entry *entry; 1445 1446 if (unlikely(dma_debug_disabled())) 1447 return; 1448 1449 if (unlikely(virt == NULL)) 1450 return; 1451 1452 entry = dma_entry_alloc(); 1453 if (!entry) 1454 return; 1455 1456 entry->type = dma_debug_coherent; 1457 entry->dev = dev; 1458 entry->pfn = page_to_pfn(virt_to_page(virt)); 1459 entry->offset = (size_t) virt & PAGE_MASK; 1460 entry->size = size; 1461 entry->dev_addr = dma_addr; 1462 entry->direction = DMA_BIDIRECTIONAL; 1463 1464 add_dma_entry(entry); 1465} 1466EXPORT_SYMBOL(debug_dma_alloc_coherent); 1467 1468void debug_dma_free_coherent(struct device *dev, size_t size, 1469 void *virt, dma_addr_t addr) 1470{ 1471 struct dma_debug_entry ref = { 1472 .type = dma_debug_coherent, 1473 .dev = dev, 1474 .pfn = page_to_pfn(virt_to_page(virt)), 1475 .offset = (size_t) virt & PAGE_MASK, 1476 .dev_addr = addr, 1477 .size = size, 1478 .direction = DMA_BIDIRECTIONAL, 1479 }; 1480 1481 if (unlikely(dma_debug_disabled())) 1482 return; 1483 1484 check_unmap(&ref); 1485} 1486EXPORT_SYMBOL(debug_dma_free_coherent); 1487 1488void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, 1489 size_t size, int direction) 1490{ 1491 struct dma_debug_entry ref; 1492 1493 if (unlikely(dma_debug_disabled())) 1494 return; 1495 1496 ref.type = dma_debug_single; 1497 ref.dev = dev; 1498 ref.dev_addr = dma_handle; 1499 ref.size = size; 1500 ref.direction = direction; 1501 ref.sg_call_ents = 0; 1502 1503 check_sync(dev, &ref, true); 1504} 1505EXPORT_SYMBOL(debug_dma_sync_single_for_cpu); 1506 1507void debug_dma_sync_single_for_device(struct device *dev, 1508 dma_addr_t dma_handle, size_t size, 1509 int direction) 1510{ 1511 struct dma_debug_entry ref; 1512 1513 if (unlikely(dma_debug_disabled())) 1514 return; 1515 1516 ref.type = dma_debug_single; 1517 ref.dev = dev; 1518 ref.dev_addr = dma_handle; 1519 ref.size = size; 1520 ref.direction = direction; 1521 ref.sg_call_ents = 0; 1522 1523 check_sync(dev, &ref, false); 1524} 1525EXPORT_SYMBOL(debug_dma_sync_single_for_device); 1526 1527void debug_dma_sync_single_range_for_cpu(struct device *dev, 1528 dma_addr_t dma_handle, 1529 unsigned long offset, size_t size, 1530 int direction) 1531{ 1532 struct dma_debug_entry ref; 1533 1534 if (unlikely(dma_debug_disabled())) 1535 return; 1536 1537 ref.type = dma_debug_single; 1538 ref.dev = dev; 1539 ref.dev_addr = dma_handle; 1540 ref.size = offset + size; 1541 ref.direction = direction; 1542 ref.sg_call_ents = 0; 1543 1544 check_sync(dev, &ref, true); 1545} 1546EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu); 1547 1548void debug_dma_sync_single_range_for_device(struct device *dev, 1549 dma_addr_t dma_handle, 1550 unsigned long offset, 1551 size_t size, int direction) 1552{ 1553 struct dma_debug_entry ref; 1554 1555 if (unlikely(dma_debug_disabled())) 1556 return; 1557 1558 ref.type = dma_debug_single; 1559 ref.dev = dev; 1560 ref.dev_addr = dma_handle; 1561 ref.size = offset + size; 1562 ref.direction = direction; 1563 ref.sg_call_ents = 0; 1564 1565 check_sync(dev, &ref, false); 1566} 1567EXPORT_SYMBOL(debug_dma_sync_single_range_for_device); 1568 1569void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, 1570 int nelems, int direction) 1571{ 1572 struct scatterlist *s; 1573 int mapped_ents = 0, i; 1574 1575 if (unlikely(dma_debug_disabled())) 1576 return; 1577 1578 for_each_sg(sg, s, nelems, i) { 1579 1580 struct dma_debug_entry ref = { 1581 .type = dma_debug_sg, 1582 .dev = dev, 1583 .pfn = page_to_pfn(sg_page(s)), 1584 .offset = s->offset, 1585 .dev_addr = sg_dma_address(s), 1586 .size = sg_dma_len(s), 1587 .direction = direction, 1588 .sg_call_ents = nelems, 1589 }; 1590 1591 if (!i) 1592 mapped_ents = get_nr_mapped_entries(dev, &ref); 1593 1594 if (i >= mapped_ents) 1595 break; 1596 1597 check_sync(dev, &ref, true); 1598 } 1599} 1600EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu); 1601 1602void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, 1603 int nelems, int direction) 1604{ 1605 struct scatterlist *s; 1606 int mapped_ents = 0, i; 1607 1608 if (unlikely(dma_debug_disabled())) 1609 return; 1610 1611 for_each_sg(sg, s, nelems, i) { 1612 1613 struct dma_debug_entry ref = { 1614 .type = dma_debug_sg, 1615 .dev = dev, 1616 .pfn = page_to_pfn(sg_page(s)), 1617 .offset = s->offset, 1618 .dev_addr = sg_dma_address(s), 1619 .size = sg_dma_len(s), 1620 .direction = direction, 1621 .sg_call_ents = nelems, 1622 }; 1623 if (!i) 1624 mapped_ents = get_nr_mapped_entries(dev, &ref); 1625 1626 if (i >= mapped_ents) 1627 break; 1628 1629 check_sync(dev, &ref, false); 1630 } 1631} 1632EXPORT_SYMBOL(debug_dma_sync_sg_for_device); 1633 1634static int __init dma_debug_driver_setup(char *str) 1635{ 1636 int i; 1637 1638 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) { 1639 current_driver_name[i] = *str; 1640 if (*str == 0) 1641 break; 1642 } 1643 1644 if (current_driver_name[0]) 1645 pr_info("DMA-API: enable driver filter for driver [%s]\n", 1646 current_driver_name); 1647 1648 1649 return 1; 1650} 1651__setup("dma_debug_driver=", dma_debug_driver_setup); 1652