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   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/device.h>
  27 #include <linux/types.h>
  28 #include <linux/sched.h>
  29 #include <linux/list.h>
  30 #include <linux/slab.h>
  31
  32 #define HASH_SIZE       1024ULL
  33 #define HASH_FN_SHIFT   13
  34 #define HASH_FN_MASK    (HASH_SIZE - 1)
  35
  36 enum {
  37         dma_debug_single,
  38         dma_debug_page,
  39         dma_debug_sg,
  40         dma_debug_coherent,
  41 };
  42
  43 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
  44
  45 struct dma_debug_entry {
  46         struct list_head list;
  47         struct device    *dev;
  48         int              type;
  49         phys_addr_t      paddr;
  50         u64              dev_addr;
  51         u64              size;
  52         int              direction;
  53         int              sg_call_ents;
  54         int              sg_mapped_ents;
  55 #ifdef CONFIG_STACKTRACE
  56         struct           stack_trace stacktrace;
  57         unsigned long    st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
  58 #endif
  59 };
  60
  61 struct hash_bucket {
  62         struct list_head list;
  63         spinlock_t lock;
  64 } ____cacheline_aligned_in_smp;
  65
  66 /* Hash list to save the allocated dma addresses */
  67 static struct hash_bucket dma_entry_hash[HASH_SIZE];
  68 /* List of pre-allocated dma_debug_entry's */
  69 static LIST_HEAD(free_entries);
  70 /* Lock for the list above */
  71 static DEFINE_SPINLOCK(free_entries_lock);
  72
  73 /* Global disable flag - will be set in case of an error */
  74 static bool global_disable __read_mostly;
  75
  76 /* Global error count */
  77 static u32 error_count;
  78
  79 /* Global error show enable*/
  80 static u32 show_all_errors __read_mostly;
  81 /* Number of errors to show */
  82 static u32 show_num_errors = 1;
  83
  84 static u32 num_free_entries;
  85 static u32 min_free_entries;
  86
  87 /* number of preallocated entries requested by kernel cmdline */
  88 static u32 req_entries;
  89
  90 /* debugfs dentry's for the stuff above */
  91 static struct dentry *dma_debug_dent        __read_mostly;
  92 static struct dentry *global_disable_dent   __read_mostly;
  93 static struct dentry *error_count_dent      __read_mostly;
  94 static struct dentry *show_all_errors_dent  __read_mostly;
  95 static struct dentry *show_num_errors_dent  __read_mostly;
  96 static struct dentry *num_free_entries_dent __read_mostly;
  97 static struct dentry *min_free_entries_dent __read_mostly;
  98
  99 static const char *type2name[4] = { "single", "page",
 100                                     "scather-gather", "coherent" };
 101
 102 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
 103                                    "DMA_FROM_DEVICE", "DMA_NONE" };
 104
 105 /*
 106  * The access to some variables in this macro is racy. We can't use atomic_t
 107  * here because all these variables are exported to debugfs. Some of them even
 108  * writeable. This is also the reason why a lock won't help much. But anyway,
 109  * the races are no big deal. Here is why:
 110  *
 111  *   error_count: the addition is racy, but the worst thing that can happen is
 112  *                that we don't count some errors
 113  *   show_num_errors: the subtraction is racy. Also no big deal because in
 114  *                    worst case this will result in one warning more in the
 115  *                    system log than the user configured. This variable is
 116  *                    writeable via debugfs.
 117  */
 118 static inline void dump_entry_trace(struct dma_debug_entry *entry)
 119 {
 120 #ifdef CONFIG_STACKTRACE
 121         if (entry) {
 122                 printk(KERN_WARNING "Mapped at:\n");
 123                 print_stack_trace(&entry->stacktrace, 0);
 124         }
 125 #endif
 126 }
 127
 128 #define err_printk(dev, entry, format, arg...) do {             \
 129                 error_count += 1;                               \
 130                 if (show_all_errors || show_num_errors > 0) {   \
 131                         WARN(1, "%s %s: " format,               \
 132                              dev_driver_string(dev),            \
 133                              dev_name(dev) , ## arg);           \
 134                         dump_entry_trace(entry);                \
 135                 }                                               \
 136                 if (!show_all_errors && show_num_errors > 0)    \
 137                         show_num_errors -= 1;                   \
 138         } while (0);
 139
 140 /*
 141  * Hash related functions
 142  *
 143  * Every DMA-API request is saved into a struct dma_debug_entry. To
 144  * have quick access to these structs they are stored into a hash.
 145  */
 146 static int hash_fn(struct dma_debug_entry *entry)
 147 {
 148         /*
 149          * Hash function is based on the dma address.
 150          * We use bits 20-27 here as the index into the hash
 151          */
 152         return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
 153 }
 154
 155 /*
 156  * Request exclusive access to a hash bucket for a given dma_debug_entry.
 157  */
 158 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
 159                                            unsigned long *flags)
 160 {
 161         int idx = hash_fn(entry);
 162         unsigned long __flags;
 163
 164         spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
 165         *flags = __flags;
 166         return &dma_entry_hash[idx];
 167 }
 168
 169 /*
 170  * Give up exclusive access to the hash bucket
 171  */
 172 static void put_hash_bucket(struct hash_bucket *bucket,
 173                             unsigned long *flags)
 174 {
 175         unsigned long __flags = *flags;
 176
 177         spin_unlock_irqrestore(&bucket->lock, __flags);
 178 }
 179
 180 /*
 181  * Search a given entry in the hash bucket list
 182  */
 183 static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
 184                                                 struct dma_debug_entry *ref)
 185 {
 186         struct dma_debug_entry *entry;
 187
 188         list_for_each_entry(entry, &bucket->list, list) {
 189                 if ((entry->dev_addr == ref->dev_addr) &&
 190                     (entry->dev == ref->dev))
 191                         return entry;
 192         }
 193
 194         return NULL;
 195 }
 196
 197 /*
 198  * Add an entry to a hash bucket
 199  */
 200 static void hash_bucket_add(struct hash_bucket *bucket,
 201                             struct dma_debug_entry *entry)
 202 {
 203         list_add_tail(&entry->list, &bucket->list);
 204 }
 205
 206 /*
 207  * Remove entry from a hash bucket list
 208  */
 209 static void hash_bucket_del(struct dma_debug_entry *entry)
 210 {
 211         list_del(&entry->list);
 212 }
 213
 214 /*
 215  * Dump mapping entries for debugging purposes
 216  */
 217 void debug_dma_dump_mappings(struct device *dev)
 218 {
 219         int idx;
 220
 221         for (idx = 0; idx < HASH_SIZE; idx++) {
 222                 struct hash_bucket *bucket = &dma_entry_hash[idx];
 223                 struct dma_debug_entry *entry;
 224                 unsigned long flags;
 225
 226                 spin_lock_irqsave(&bucket->lock, flags);
 227
 228                 list_for_each_entry(entry, &bucket->list, list) {
 229                         if (!dev || dev == entry->dev) {
 230                                 dev_info(entry->dev,
 231                                          "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
 232                                          type2name[entry->type], idx,
 233                                          (unsigned long long)entry->paddr,
 234                                          entry->dev_addr, entry->size,
 235                                          dir2name[entry->direction]);
 236                         }
 237                 }
 238
 239                 spin_unlock_irqrestore(&bucket->lock, flags);
 240         }
 241 }
 242 EXPORT_SYMBOL(debug_dma_dump_mappings);
 243
 244 /*
 245  * Wrapper function for adding an entry to the hash.
 246  * This function takes care of locking itself.
 247  */
 248 static void add_dma_entry(struct dma_debug_entry *entry)
 249 {
 250         struct hash_bucket *bucket;
 251         unsigned long flags;
 252
 253         bucket = get_hash_bucket(entry, &flags);
 254         hash_bucket_add(bucket, entry);
 255         put_hash_bucket(bucket, &flags);
 256 }
 257
 258 /* struct dma_entry allocator
 259  *
 260  * The next two functions implement the allocator for
 261  * struct dma_debug_entries.
 262  */
 263 static struct dma_debug_entry *dma_entry_alloc(void)
 264 {
 265         struct dma_debug_entry *entry = NULL;
 266         unsigned long flags;
 267
 268         spin_lock_irqsave(&free_entries_lock, flags);
 269
 270         if (list_empty(&free_entries)) {
 271                 printk(KERN_ERR "DMA-API: debugging out of memory "
 272                                 "- disabling\n");
 273                 global_disable = true;
 274                 goto out;
 275         }
 276
 277         entry = list_entry(free_entries.next, struct dma_debug_entry, list);
 278         list_del(&entry->list);
 279         memset(entry, 0, sizeof(*entry));
 280
 281 #ifdef CONFIG_STACKTRACE
 282         entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
 283         entry->stacktrace.entries = entry->st_entries;
 284         entry->stacktrace.skip = 2;
 285         save_stack_trace(&entry->stacktrace);
 286 #endif
 287         num_free_entries -= 1;
 288         if (num_free_entries < min_free_entries)
 289                 min_free_entries = num_free_entries;
 290
 291 out:
 292         spin_unlock_irqrestore(&free_entries_lock, flags);
 293
 294         return entry;
 295 }
 296
 297 static void dma_entry_free(struct dma_debug_entry *entry)
 298 {
 299         unsigned long flags;
 300
 301         /*
 302          * add to beginning of the list - this way the entries are
 303          * more likely cache hot when they are reallocated.
 304          */
 305         spin_lock_irqsave(&free_entries_lock, flags);
 306         list_add(&entry->list, &free_entries);
 307         num_free_entries += 1;
 308         spin_unlock_irqrestore(&free_entries_lock, flags);
 309 }
 310
 311 /*
 312  * DMA-API debugging init code
 313  *
 314  * The init code does two things:
 315  *   1. Initialize core data structures
 316  *   2. Preallocate a given number of dma_debug_entry structs
 317  */
 318
 319 static int prealloc_memory(u32 num_entries)
 320 {
 321         struct dma_debug_entry *entry, *next_entry;
 322         int i;
 323
 324         for (i = 0; i < num_entries; ++i) {
 325                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 326                 if (!entry)
 327                         goto out_err;
 328
 329                 list_add_tail(&entry->list, &free_entries);
 330         }
 331
 332         num_free_entries = num_entries;
 333         min_free_entries = num_entries;
 334
 335         printk(KERN_INFO "DMA-API: preallocated %d debug entries\n",
 336                         num_entries);
 337
 338         return 0;
 339
 340 out_err:
 341
 342         list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
 343                 list_del(&entry->list);
 344                 kfree(entry);
 345         }
 346
 347         return -ENOMEM;
 348 }
 349
 350 static int dma_debug_fs_init(void)
 351 {
 352         dma_debug_dent = debugfs_create_dir("dma-api", NULL);
 353         if (!dma_debug_dent) {
 354                 printk(KERN_ERR "DMA-API: can not create debugfs directory\n");
 355                 return -ENOMEM;
 356         }
 357
 358         global_disable_dent = debugfs_create_bool("disabled", 0444,
 359                         dma_debug_dent,
 360                         (u32 *)&global_disable);
 361         if (!global_disable_dent)
 362                 goto out_err;
 363
 364         error_count_dent = debugfs_create_u32("error_count", 0444,
 365                         dma_debug_dent, &error_count);
 366         if (!error_count_dent)
 367                 goto out_err;
 368
 369         show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
 370                         dma_debug_dent,
 371                         &show_all_errors);
 372         if (!show_all_errors_dent)
 373                 goto out_err;
 374
 375         show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
 376                         dma_debug_dent,
 377                         &show_num_errors);
 378         if (!show_num_errors_dent)
 379                 goto out_err;
 380
 381         num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
 382                         dma_debug_dent,
 383                         &num_free_entries);
 384         if (!num_free_entries_dent)
 385                 goto out_err;
 386
 387         min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
 388                         dma_debug_dent,
 389                         &min_free_entries);
 390         if (!min_free_entries_dent)
 391                 goto out_err;
 392
 393         return 0;
 394
 395 out_err:
 396         debugfs_remove_recursive(dma_debug_dent);
 397
 398         return -ENOMEM;
 399 }
 400
 401
 402 /*
 403  * Let the architectures decide how many entries should be preallocated.
 404  */
 405 void dma_debug_init(u32 num_entries)
 406 {
 407         int i;
 408
 409         if (global_disable)
 410                 return;
 411
 412         for (i = 0; i < HASH_SIZE; ++i) {
 413                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
 414                 dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
 415         }
 416
 417         if (dma_debug_fs_init() != 0) {
 418                 printk(KERN_ERR "DMA-API: error creating debugfs entries "
 419                                 "- disabling\n");
 420                 global_disable = true;
 421
 422                 return;
 423         }
 424
 425         if (req_entries)
 426                 num_entries = req_entries;
 427
 428         if (prealloc_memory(num_entries) != 0) {
 429                 printk(KERN_ERR "DMA-API: debugging out of memory error "
 430                                 "- disabled\n");
 431                 global_disable = true;
 432
 433                 return;
 434         }
 435
 436         printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
 437 }
 438
 439 static __init int dma_debug_cmdline(char *str)
 440 {
 441         if (!str)
 442                 return -EINVAL;
 443
 444         if (strncmp(str, "off", 3) == 0) {
 445                 printk(KERN_INFO "DMA-API: debugging disabled on kernel "
 446                                  "command line\n");
 447                 global_disable = true;
 448         }
 449
 450         return 0;
 451 }
 452
 453 static __init int dma_debug_entries_cmdline(char *str)
 454 {
 455         int res;
 456
 457         if (!str)
 458                 return -EINVAL;
 459
 460         res = get_option(&str, &req_entries);
 461
 462         if (!res)
 463                 req_entries = 0;
 464
 465         return 0;
 466 }
 467
 468 __setup("dma_debug=", dma_debug_cmdline);
 469 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
 470
 471 static void check_unmap(struct dma_debug_entry *ref)
 472 {
 473         struct dma_debug_entry *entry;
 474         struct hash_bucket *bucket;
 475         unsigned long flags;
 476
 477         if (dma_mapping_error(ref->dev, ref->dev_addr))
 478                 return;
 479
 480         bucket = get_hash_bucket(ref, &flags);
 481         entry = hash_bucket_find(bucket, ref);
 482
 483         if (!entry) {
 484                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
 485                            "to free DMA memory it has not allocated "
 486                            "[device address=0x%016llx] [size=%llu bytes]\n",
 487                            ref->dev_addr, ref->size);
 488                 goto out;
 489         }
 490
 491         if (ref->size != entry->size) {
 492                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 493                            "DMA memory with different size "
 494                            "[device address=0x%016llx] [map size=%llu bytes] "
 495                            "[unmap size=%llu bytes]\n",
 496                            ref->dev_addr, entry->size, ref->size);
 497         }
 498
 499         if (ref->type != entry->type) {
 500                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 501                            "DMA memory with wrong function "
 502                            "[device address=0x%016llx] [size=%llu bytes] "
 503                            "[mapped as %s] [unmapped as %s]\n",
 504                            ref->dev_addr, ref->size,
 505                            type2name[entry->type], type2name[ref->type]);
 506         } else if ((entry->type == dma_debug_coherent) &&
 507                    (ref->paddr != entry->paddr)) {
 508                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 509                            "DMA memory with different CPU address "
 510                            "[device address=0x%016llx] [size=%llu bytes] "
 511                            "[cpu alloc address=%p] [cpu free address=%p]",
 512                            ref->dev_addr, ref->size,
 513                            (void *)entry->paddr, (void *)ref->paddr);
 514         }
 515
 516         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
 517             ref->sg_call_ents != entry->sg_call_ents) {
 518                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 519                            "DMA sg list with different entry count "
 520                            "[map count=%d] [unmap count=%d]\n",
 521                            entry->sg_call_ents, ref->sg_call_ents);
 522         }
 523
 524         /*
 525          * This may be no bug in reality - but most implementations of the
 526          * DMA API don't handle this properly, so check for it here
 527          */
 528         if (ref->direction != entry->direction) {
 529                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 530                            "DMA memory with different direction "
 531                            "[device address=0x%016llx] [size=%llu bytes] "
 532                            "[mapped with %s] [unmapped with %s]\n",
 533                            ref->dev_addr, ref->size,
 534                            dir2name[entry->direction],
 535                            dir2name[ref->direction]);
 536         }
 537
 538         hash_bucket_del(entry);
 539         dma_entry_free(entry);
 540
 541 out:
 542         put_hash_bucket(bucket, &flags);
 543 }
 544
 545 static void check_for_stack(struct device *dev, void *addr)
 546 {
 547         if (object_is_on_stack(addr))
 548                 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
 549                                 "stack [addr=%p]\n", addr);
 550 }
 551
 552 static void check_sync(struct device *dev, dma_addr_t addr,
 553                        u64 size, u64 offset, int direction, bool to_cpu)
 554 {
 555         struct dma_debug_entry ref = {
 556                 .dev            = dev,
 557                 .dev_addr       = addr,
 558                 .size           = size,
 559                 .direction      = direction,
 560         };
 561         struct dma_debug_entry *entry;
 562         struct hash_bucket *bucket;
 563         unsigned long flags;
 564
 565         bucket = get_hash_bucket(&ref, &flags);
 566
 567         entry = hash_bucket_find(bucket, &ref);
 568
 569         if (!entry) {
 570                 err_printk(dev, NULL, "DMA-API: device driver tries "
 571                                 "to sync DMA memory it has not allocated "
 572                                 "[device address=0x%016llx] [size=%llu bytes]\n",
 573                                 addr, size);
 574                 goto out;
 575         }
 576
 577         if ((offset + size) > entry->size) {
 578                 err_printk(dev, entry, "DMA-API: device driver syncs"
 579                                 " DMA memory outside allocated range "
 580                                 "[device address=0x%016llx] "
 581                                 "[allocation size=%llu bytes] [sync offset=%llu] "
 582                                 "[sync size=%llu]\n", entry->dev_addr, entry->size,
 583                                 offset, size);
 584         }
 585
 586         if (direction != entry->direction) {
 587                 err_printk(dev, entry, "DMA-API: device driver syncs "
 588                                 "DMA memory with different direction "
 589                                 "[device address=0x%016llx] [size=%llu bytes] "
 590                                 "[mapped with %s] [synced with %s]\n",
 591                                 addr, entry->size,
 592                                 dir2name[entry->direction],
 593                                 dir2name[direction]);
 594         }
 595
 596         if (entry->direction == DMA_BIDIRECTIONAL)
 597                 goto out;
 598
 599         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
 600                       !(direction == DMA_TO_DEVICE))
 601                 err_printk(dev, entry, "DMA-API: device driver syncs "
 602                                 "device read-only DMA memory for cpu "
 603                                 "[device address=0x%016llx] [size=%llu bytes] "
 604                                 "[mapped with %s] [synced with %s]\n",
 605                                 addr, entry->size,
 606                                 dir2name[entry->direction],
 607                                 dir2name[direction]);
 608
 609         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
 610                        !(direction == DMA_FROM_DEVICE))
 611                 err_printk(dev, entry, "DMA-API: device driver syncs "
 612                                 "device write-only DMA memory to device "
 613                                 "[device address=0x%016llx] [size=%llu bytes] "
 614                                 "[mapped with %s] [synced with %s]\n",
 615                                 addr, entry->size,
 616                                 dir2name[entry->direction],
 617                                 dir2name[direction]);
 618
 619 out:
 620         put_hash_bucket(bucket, &flags);
 621
 622 }
 623
 624 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
 625                         size_t size, int direction, dma_addr_t dma_addr,
 626                         bool map_single)
 627 {
 628         struct dma_debug_entry *entry;
 629
 630         if (unlikely(global_disable))
 631                 return;
 632
 633         if (unlikely(dma_mapping_error(dev, dma_addr)))
 634                 return;
 635
 636         entry = dma_entry_alloc();
 637         if (!entry)
 638                 return;
 639
 640         entry->dev       = dev;
 641         entry->type      = dma_debug_page;
 642         entry->paddr     = page_to_phys(page) + offset;
 643         entry->dev_addr  = dma_addr;
 644         entry->size      = size;
 645         entry->direction = direction;
 646
 647         if (map_single) {
 648                 entry->type = dma_debug_single;
 649                 check_for_stack(dev, page_address(page) + offset);
 650         }
 651
 652         add_dma_entry(entry);
 653 }
 654 EXPORT_SYMBOL(debug_dma_map_page);
 655
 656 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 657                           size_t size, int direction, bool map_single)
 658 {
 659         struct dma_debug_entry ref = {
 660                 .type           = dma_debug_page,
 661                 .dev            = dev,
 662                 .dev_addr       = addr,
 663                 .size           = size,
 664                 .direction      = direction,
 665         };
 666
 667         if (unlikely(global_disable))
 668                 return;
 669
 670         if (map_single)
 671                 ref.type = dma_debug_single;
 672
 673         check_unmap(&ref);
 674 }
 675 EXPORT_SYMBOL(debug_dma_unmap_page);
 676
 677 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
 678                       int nents, int mapped_ents, int direction)
 679 {
 680         struct dma_debug_entry *entry;
 681         struct scatterlist *s;
 682         int i;
 683
 684         if (unlikely(global_disable))
 685                 return;
 686
 687         for_each_sg(sg, s, mapped_ents, i) {
 688                 entry = dma_entry_alloc();
 689                 if (!entry)
 690                         return;
 691
 692                 entry->type           = dma_debug_sg;
 693                 entry->dev            = dev;
 694                 entry->paddr          = sg_phys(s);
 695                 entry->size           = s->length;
 696                 entry->dev_addr       = s->dma_address;
 697                 entry->direction      = direction;
 698                 entry->sg_call_ents   = nents;
 699                 entry->sg_mapped_ents = mapped_ents;
 700
 701                 check_for_stack(dev, sg_virt(s));
 702
 703                 add_dma_entry(entry);
 704         }
 705 }
 706 EXPORT_SYMBOL(debug_dma_map_sg);
 707
 708 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 709                         int nelems, int dir)
 710 {
 711         struct dma_debug_entry *entry;
 712         struct scatterlist *s;
 713         int mapped_ents = 0, i;
 714         unsigned long flags;
 715
 716         if (unlikely(global_disable))
 717                 return;
 718
 719         for_each_sg(sglist, s, nelems, i) {
 720
 721                 struct dma_debug_entry ref = {
 722                         .type           = dma_debug_sg,
 723                         .dev            = dev,
 724                         .paddr          = sg_phys(s),
 725                         .dev_addr       = s->dma_address,
 726                         .size           = s->length,
 727                         .direction      = dir,
 728                         .sg_call_ents   = 0,
 729                 };
 730
 731                 if (mapped_ents && i >= mapped_ents)
 732                         break;
 733
 734                 if (mapped_ents == 0) {
 735                         struct hash_bucket *bucket;
 736                         ref.sg_call_ents = nelems;
 737                         bucket = get_hash_bucket(&ref, &flags);
 738                         entry = hash_bucket_find(bucket, &ref);
 739                         if (entry)
 740                                 mapped_ents = entry->sg_mapped_ents;
 741                         put_hash_bucket(bucket, &flags);
 742                 }
 743
 744                 check_unmap(&ref);
 745         }
 746 }
 747 EXPORT_SYMBOL(debug_dma_unmap_sg);
 748
 749 void debug_dma_alloc_coherent(struct device *dev, size_t size,
 750                               dma_addr_t dma_addr, void *virt)
 751 {
 752         struct dma_debug_entry *entry;
 753
 754         if (unlikely(global_disable))
 755                 return;
 756
 757         if (unlikely(virt == NULL))
 758                 return;
 759
 760         entry = dma_entry_alloc();
 761         if (!entry)
 762                 return;
 763
 764         entry->type      = dma_debug_coherent;
 765         entry->dev       = dev;
 766         entry->paddr     = virt_to_phys(virt);
 767         entry->size      = size;
 768         entry->dev_addr  = dma_addr;
 769         entry->direction = DMA_BIDIRECTIONAL;
 770
 771         add_dma_entry(entry);
 772 }
 773 EXPORT_SYMBOL(debug_dma_alloc_coherent);
 774
 775 void debug_dma_free_coherent(struct device *dev, size_t size,
 776                          void *virt, dma_addr_t addr)
 777 {
 778         struct dma_debug_entry ref = {
 779                 .type           = dma_debug_coherent,
 780                 .dev            = dev,
 781                 .paddr          = virt_to_phys(virt),
 782                 .dev_addr       = addr,
 783                 .size           = size,
 784                 .direction      = DMA_BIDIRECTIONAL,
 785         };
 786
 787         if (unlikely(global_disable))
 788                 return;
 789
 790         check_unmap(&ref);
 791 }
 792 EXPORT_SYMBOL(debug_dma_free_coherent);
 793
 794 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 795                                    size_t size, int direction)
 796 {
 797         if (unlikely(global_disable))
 798                 return;
 799
 800         check_sync(dev, dma_handle, size, 0, direction, true);
 801 }
 802 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
 803
 804 void debug_dma_sync_single_for_device(struct device *dev,
 805                                       dma_addr_t dma_handle, size_t size,
 806                                       int direction)
 807 {
 808         if (unlikely(global_disable))
 809                 return;
 810
 811         check_sync(dev, dma_handle, size, 0, direction, false);
 812 }
 813 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
 814
 815 void debug_dma_sync_single_range_for_cpu(struct device *dev,
 816                                          dma_addr_t dma_handle,
 817                                          unsigned long offset, size_t size,
 818                                          int direction)
 819 {
 820         if (unlikely(global_disable))
 821                 return;
 822
 823         check_sync(dev, dma_handle, size, offset, direction, true);
 824 }
 825 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
 826
 827 void debug_dma_sync_single_range_for_device(struct device *dev,
 828                                             dma_addr_t dma_handle,
 829                                             unsigned long offset,
 830                                             size_t size, int direction)
 831 {
 832         if (unlikely(global_disable))
 833                 return;
 834
 835         check_sync(dev, dma_handle, size, offset, direction, false);
 836 }
 837 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
 838
 839 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 840                                int nelems, int direction)
 841 {
 842         struct scatterlist *s;
 843         int i;
 844
 845         if (unlikely(global_disable))
 846                 return;
 847
 848         for_each_sg(sg, s, nelems, i) {
 849                 check_sync(dev, s->dma_address, s->dma_length, 0,
 850                                 direction, true);
 851         }
 852 }
 853 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
 854
 855 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 856                                   int nelems, int direction)
 857 {
 858         struct scatterlist *s;
 859         int i;
 860
 861         if (unlikely(global_disable))
 862                 return;
 863
 864         for_each_sg(sg, s, nelems, i) {
 865                 check_sync(dev, s->dma_address, s->dma_length, 0,
 866                                 direction, false);
 867         }
 868 }
 869 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
 870