lib/dma-debug.c

   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 #include <asm/sections.h>
  33
  34 #define HASH_SIZE       1024ULL
  35 #define HASH_FN_SHIFT   13
  36 #define HASH_FN_MASK    (HASH_SIZE - 1)
  37
  38 enum {
  39         dma_debug_single,
  40         dma_debug_page,
  41         dma_debug_sg,
  42         dma_debug_coherent,
  43 };
  44
  45 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
  46
  47 struct dma_debug_entry {
  48         struct list_head list;
  49         struct device    *dev;
  50         int              type;
  51         phys_addr_t      paddr;
  52         u64              dev_addr;
  53         u64              size;
  54         int              direction;
  55         int              sg_call_ents;
  56         int              sg_mapped_ents;
  57 #ifdef CONFIG_STACKTRACE
  58         struct           stack_trace stacktrace;
  59         unsigned long    st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
  60 #endif
  61 };
  62
  63 struct hash_bucket {
  64         struct list_head list;
  65         spinlock_t lock;
  66 } ____cacheline_aligned_in_smp;
  67
  68 /* Hash list to save the allocated dma addresses */
  69 static struct hash_bucket dma_entry_hash[HASH_SIZE];
  70 /* List of pre-allocated dma_debug_entry's */
  71 static LIST_HEAD(free_entries);
  72 /* Lock for the list above */
  73 static DEFINE_SPINLOCK(free_entries_lock);
  74
  75 /* Global disable flag - will be set in case of an error */
  76 static bool global_disable __read_mostly;
  77
  78 /* Global error count */
  79 static u32 error_count;
  80
  81 /* Global error show enable*/
  82 static u32 show_all_errors __read_mostly;
  83 /* Number of errors to show */
  84 static u32 show_num_errors = 1;
  85
  86 static u32 num_free_entries;
  87 static u32 min_free_entries;
  88
  89 /* number of preallocated entries requested by kernel cmdline */
  90 static u32 req_entries;
  91
  92 /* debugfs dentry's for the stuff above */
  93 static struct dentry *dma_debug_dent        __read_mostly;
  94 static struct dentry *global_disable_dent   __read_mostly;
  95 static struct dentry *error_count_dent      __read_mostly;
  96 static struct dentry *show_all_errors_dent  __read_mostly;
  97 static struct dentry *show_num_errors_dent  __read_mostly;
  98 static struct dentry *num_free_entries_dent __read_mostly;
  99 static struct dentry *min_free_entries_dent __read_mostly;
 100
 101 static const char *type2name[4] = { "single", "page",
 102                                     "scather-gather", "coherent" };
 103
 104 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
 105                                    "DMA_FROM_DEVICE", "DMA_NONE" };
 106
 107 /*
 108  * The access to some variables in this macro is racy. We can't use atomic_t
 109  * here because all these variables are exported to debugfs. Some of them even
 110  * writeable. This is also the reason why a lock won't help much. But anyway,
 111  * the races are no big deal. Here is why:
 112  *
 113  *   error_count: the addition is racy, but the worst thing that can happen is
 114  *                that we don't count some errors
 115  *   show_num_errors: the subtraction is racy. Also no big deal because in
 116  *                    worst case this will result in one warning more in the
 117  *                    system log than the user configured. This variable is
 118  *                    writeable via debugfs.
 119  */
 120 static inline void dump_entry_trace(struct dma_debug_entry *entry)
 121 {
 122 #ifdef CONFIG_STACKTRACE
 123         if (entry) {
 124                 printk(KERN_WARNING "Mapped at:\n");
 125                 print_stack_trace(&entry->stacktrace, 0);
 126         }
 127 #endif
 128 }
 129
 130 #define err_printk(dev, entry, format, arg...) do {             \
 131                 error_count += 1;                               \
 132                 if (show_all_errors || show_num_errors > 0) {   \
 133                         WARN(1, "%s %s: " format,               \
 134                              dev_driver_string(dev),            \
 135                              dev_name(dev) , ## arg);           \
 136                         dump_entry_trace(entry);                \
 137                 }                                               \
 138                 if (!show_all_errors && show_num_errors > 0)    \
 139                         show_num_errors -= 1;                   \
 140         } while (0);
 141
 142 /*
 143  * Hash related functions
 144  *
 145  * Every DMA-API request is saved into a struct dma_debug_entry. To
 146  * have quick access to these structs they are stored into a hash.
 147  */
 148 static int hash_fn(struct dma_debug_entry *entry)
 149 {
 150         /*
 151          * Hash function is based on the dma address.
 152          * We use bits 20-27 here as the index into the hash
 153          */
 154         return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
 155 }
 156
 157 /*
 158  * Request exclusive access to a hash bucket for a given dma_debug_entry.
 159  */
 160 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
 161                                            unsigned long *flags)
 162 {
 163         int idx = hash_fn(entry);
 164         unsigned long __flags;
 165
 166         spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
 167         *flags = __flags;
 168         return &dma_entry_hash[idx];
 169 }
 170
 171 /*
 172  * Give up exclusive access to the hash bucket
 173  */
 174 static void put_hash_bucket(struct hash_bucket *bucket,
 175                             unsigned long *flags)
 176 {
 177         unsigned long __flags = *flags;
 178
 179         spin_unlock_irqrestore(&bucket->lock, __flags);
 180 }
 181
 182 /*
 183  * Search a given entry in the hash bucket list
 184  */
 185 static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
 186                                                 struct dma_debug_entry *ref)
 187 {
 188         struct dma_debug_entry *entry, *ret = NULL;
 189         int matches = 0, match_lvl, last_lvl = 0;
 190
 191         list_for_each_entry(entry, &bucket->list, list) {
 192                 if ((entry->dev_addr != ref->dev_addr) ||
 193                     (entry->dev != ref->dev))
 194                         continue;
 195
 196                 /*
 197                  * Some drivers map the same physical address multiple
 198                  * times. Without a hardware IOMMU this results in the
 199                  * same device addresses being put into the dma-debug
 200                  * hash multiple times too. This can result in false
 201                  * positives being reported. Therfore we implement a
 202                  * best-fit algorithm here which returns the entry from
 203                  * the hash which fits best to the reference value
 204                  * instead of the first-fit.
 205                  */
 206                 matches += 1;
 207                 match_lvl = 0;
 208                 entry->size      == ref->size      ? ++match_lvl : match_lvl;
 209                 entry->type      == ref->type      ? ++match_lvl : match_lvl;
 210                 entry->direction == ref->direction ? ++match_lvl : match_lvl;
 211
 212                 if (match_lvl == 3) {
 213                         /* perfect-fit - return the result */
 214                         return entry;
 215                 } else if (match_lvl > last_lvl) {
 216                         /*
 217                          * We found an entry that fits better then the
 218                          * previous one
 219                          */
 220                         last_lvl = match_lvl;
 221                         ret      = entry;
 222                 }
 223         }
 224
 225         /*
 226          * If we have multiple matches but no perfect-fit, just return
 227          * NULL.
 228          */
 229         ret = (matches == 1) ? ret : NULL;
 230
 231         return ret;
 232 }
 233
 234 /*
 235  * Add an entry to a hash bucket
 236  */
 237 static void hash_bucket_add(struct hash_bucket *bucket,
 238                             struct dma_debug_entry *entry)
 239 {
 240         list_add_tail(&entry->list, &bucket->list);
 241 }
 242
 243 /*
 244  * Remove entry from a hash bucket list
 245  */
 246 static void hash_bucket_del(struct dma_debug_entry *entry)
 247 {
 248         list_del(&entry->list);
 249 }
 250
 251 /*
 252  * Dump mapping entries for debugging purposes
 253  */
 254 void debug_dma_dump_mappings(struct device *dev)
 255 {
 256         int idx;
 257
 258         for (idx = 0; idx < HASH_SIZE; idx++) {
 259                 struct hash_bucket *bucket = &dma_entry_hash[idx];
 260                 struct dma_debug_entry *entry;
 261                 unsigned long flags;
 262
 263                 spin_lock_irqsave(&bucket->lock, flags);
 264
 265                 list_for_each_entry(entry, &bucket->list, list) {
 266                         if (!dev || dev == entry->dev) {
 267                                 dev_info(entry->dev,
 268                                          "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
 269                                          type2name[entry->type], idx,
 270                                          (unsigned long long)entry->paddr,
 271                                          entry->dev_addr, entry->size,
 272                                          dir2name[entry->direction]);
 273                         }
 274                 }
 275
 276                 spin_unlock_irqrestore(&bucket->lock, flags);
 277         }
 278 }
 279 EXPORT_SYMBOL(debug_dma_dump_mappings);
 280
 281 /*
 282  * Wrapper function for adding an entry to the hash.
 283  * This function takes care of locking itself.
 284  */
 285 static void add_dma_entry(struct dma_debug_entry *entry)
 286 {
 287         struct hash_bucket *bucket;
 288         unsigned long flags;
 289
 290         bucket = get_hash_bucket(entry, &flags);
 291         hash_bucket_add(bucket, entry);
 292         put_hash_bucket(bucket, &flags);
 293 }
 294
 295 /* struct dma_entry allocator
 296  *
 297  * The next two functions implement the allocator for
 298  * struct dma_debug_entries.
 299  */
 300 static struct dma_debug_entry *dma_entry_alloc(void)
 301 {
 302         struct dma_debug_entry *entry = NULL;
 303         unsigned long flags;
 304
 305         spin_lock_irqsave(&free_entries_lock, flags);
 306
 307         if (list_empty(&free_entries)) {
 308                 printk(KERN_ERR "DMA-API: debugging out of memory "
 309                                 "- disabling\n");
 310                 global_disable = true;
 311                 goto out;
 312         }
 313
 314         entry = list_entry(free_entries.next, struct dma_debug_entry, list);
 315         list_del(&entry->list);
 316         memset(entry, 0, sizeof(*entry));
 317
 318 #ifdef CONFIG_STACKTRACE
 319         entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
 320         entry->stacktrace.entries = entry->st_entries;
 321         entry->stacktrace.skip = 2;
 322         save_stack_trace(&entry->stacktrace);
 323 #endif
 324         num_free_entries -= 1;
 325         if (num_free_entries < min_free_entries)
 326                 min_free_entries = num_free_entries;
 327
 328 out:
 329         spin_unlock_irqrestore(&free_entries_lock, flags);
 330
 331         return entry;
 332 }
 333
 334 static void dma_entry_free(struct dma_debug_entry *entry)
 335 {
 336         unsigned long flags;
 337
 338         /*
 339          * add to beginning of the list - this way the entries are
 340          * more likely cache hot when they are reallocated.
 341          */
 342         spin_lock_irqsave(&free_entries_lock, flags);
 343         list_add(&entry->list, &free_entries);
 344         num_free_entries += 1;
 345         spin_unlock_irqrestore(&free_entries_lock, flags);
 346 }
 347
 348 /*
 349  * DMA-API debugging init code
 350  *
 351  * The init code does two things:
 352  *   1. Initialize core data structures
 353  *   2. Preallocate a given number of dma_debug_entry structs
 354  */
 355
 356 static int prealloc_memory(u32 num_entries)
 357 {
 358         struct dma_debug_entry *entry, *next_entry;
 359         int i;
 360
 361         for (i = 0; i < num_entries; ++i) {
 362                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 363                 if (!entry)
 364                         goto out_err;
 365
 366                 list_add_tail(&entry->list, &free_entries);
 367         }
 368
 369         num_free_entries = num_entries;
 370         min_free_entries = num_entries;
 371
 372         printk(KERN_INFO "DMA-API: preallocated %d debug entries\n",
 373                         num_entries);
 374
 375         return 0;
 376
 377 out_err:
 378
 379         list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
 380                 list_del(&entry->list);
 381                 kfree(entry);
 382         }
 383
 384         return -ENOMEM;
 385 }
 386
 387 static int dma_debug_fs_init(void)
 388 {
 389         dma_debug_dent = debugfs_create_dir("dma-api", NULL);
 390         if (!dma_debug_dent) {
 391                 printk(KERN_ERR "DMA-API: can not create debugfs directory\n");
 392                 return -ENOMEM;
 393         }
 394
 395         global_disable_dent = debugfs_create_bool("disabled", 0444,
 396                         dma_debug_dent,
 397                         (u32 *)&global_disable);
 398         if (!global_disable_dent)
 399                 goto out_err;
 400
 401         error_count_dent = debugfs_create_u32("error_count", 0444,
 402                         dma_debug_dent, &error_count);
 403         if (!error_count_dent)
 404                 goto out_err;
 405
 406         show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
 407                         dma_debug_dent,
 408                         &show_all_errors);
 409         if (!show_all_errors_dent)
 410                 goto out_err;
 411
 412         show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
 413                         dma_debug_dent,
 414                         &show_num_errors);
 415         if (!show_num_errors_dent)
 416                 goto out_err;
 417
 418         num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
 419                         dma_debug_dent,
 420                         &num_free_entries);
 421         if (!num_free_entries_dent)
 422                 goto out_err;
 423
 424         min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
 425                         dma_debug_dent,
 426                         &min_free_entries);
 427         if (!min_free_entries_dent)
 428                 goto out_err;
 429
 430         return 0;
 431
 432 out_err:
 433         debugfs_remove_recursive(dma_debug_dent);
 434
 435         return -ENOMEM;
 436 }
 437
 438 void dma_debug_add_bus(struct bus_type *bus)
 439 {
 440         /* FIXME: register notifier */
 441 }
 442
 443 /*
 444  * Let the architectures decide how many entries should be preallocated.
 445  */
 446 void dma_debug_init(u32 num_entries)
 447 {
 448         int i;
 449
 450         if (global_disable)
 451                 return;
 452
 453         for (i = 0; i < HASH_SIZE; ++i) {
 454                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
 455                 dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
 456         }
 457
 458         if (dma_debug_fs_init() != 0) {
 459                 printk(KERN_ERR "DMA-API: error creating debugfs entries "
 460                                 "- disabling\n");
 461                 global_disable = true;
 462
 463                 return;
 464         }
 465
 466         if (req_entries)
 467                 num_entries = req_entries;
 468
 469         if (prealloc_memory(num_entries) != 0) {
 470                 printk(KERN_ERR "DMA-API: debugging out of memory error "
 471                                 "- disabled\n");
 472                 global_disable = true;
 473
 474                 return;
 475         }
 476
 477         printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
 478 }
 479
 480 static __init int dma_debug_cmdline(char *str)
 481 {
 482         if (!str)
 483                 return -EINVAL;
 484
 485         if (strncmp(str, "off", 3) == 0) {
 486                 printk(KERN_INFO "DMA-API: debugging disabled on kernel "
 487                                  "command line\n");
 488                 global_disable = true;
 489         }
 490
 491         return 0;
 492 }
 493
 494 static __init int dma_debug_entries_cmdline(char *str)
 495 {
 496         int res;
 497
 498         if (!str)
 499                 return -EINVAL;
 500
 501         res = get_option(&str, &req_entries);
 502
 503         if (!res)
 504                 req_entries = 0;
 505
 506         return 0;
 507 }
 508
 509 __setup("dma_debug=", dma_debug_cmdline);
 510 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
 511
 512 static void check_unmap(struct dma_debug_entry *ref)
 513 {
 514         struct dma_debug_entry *entry;
 515         struct hash_bucket *bucket;
 516         unsigned long flags;
 517
 518         if (dma_mapping_error(ref->dev, ref->dev_addr)) {
 519                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
 520                            "to free an invalid DMA memory address\n");
 521                 return;
 522         }
 523
 524         bucket = get_hash_bucket(ref, &flags);
 525         entry = hash_bucket_find(bucket, ref);
 526
 527         if (!entry) {
 528                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
 529                            "to free DMA memory it has not allocated "
 530                            "[device address=0x%016llx] [size=%llu bytes]\n",
 531                            ref->dev_addr, ref->size);
 532                 goto out;
 533         }
 534
 535         if (ref->size != entry->size) {
 536                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 537                            "DMA memory with different size "
 538                            "[device address=0x%016llx] [map size=%llu bytes] "
 539                            "[unmap size=%llu bytes]\n",
 540                            ref->dev_addr, entry->size, ref->size);
 541         }
 542
 543         if (ref->type != entry->type) {
 544                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 545                            "DMA memory with wrong function "
 546                            "[device address=0x%016llx] [size=%llu bytes] "
 547                            "[mapped as %s] [unmapped as %s]\n",
 548                            ref->dev_addr, ref->size,
 549                            type2name[entry->type], type2name[ref->type]);
 550         } else if ((entry->type == dma_debug_coherent) &&
 551                    (ref->paddr != entry->paddr)) {
 552                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 553                            "DMA memory with different CPU address "
 554                            "[device address=0x%016llx] [size=%llu bytes] "
 555                            "[cpu alloc address=%p] [cpu free address=%p]",
 556                            ref->dev_addr, ref->size,
 557                            (void *)entry->paddr, (void *)ref->paddr);
 558         }
 559
 560         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
 561             ref->sg_call_ents != entry->sg_call_ents) {
 562                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 563                            "DMA sg list with different entry count "
 564                            "[map count=%d] [unmap count=%d]\n",
 565                            entry->sg_call_ents, ref->sg_call_ents);
 566         }
 567
 568         /*
 569          * This may be no bug in reality - but most implementations of the
 570          * DMA API don't handle this properly, so check for it here
 571          */
 572         if (ref->direction != entry->direction) {
 573                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 574                            "DMA memory with different direction "
 575                            "[device address=0x%016llx] [size=%llu bytes] "
 576                            "[mapped with %s] [unmapped with %s]\n",
 577                            ref->dev_addr, ref->size,
 578                            dir2name[entry->direction],
 579                            dir2name[ref->direction]);
 580         }
 581
 582         hash_bucket_del(entry);
 583         dma_entry_free(entry);
 584
 585 out:
 586         put_hash_bucket(bucket, &flags);
 587 }
 588
 589 static void check_for_stack(struct device *dev, void *addr)
 590 {
 591         if (object_is_on_stack(addr))
 592                 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
 593                                 "stack [addr=%p]\n", addr);
 594 }
 595
 596 static inline bool overlap(void *addr, u64 size, void *start, void *end)
 597 {
 598         void *addr2 = (char *)addr + size;
 599
 600         return ((addr >= start && addr < end) ||
 601                 (addr2 >= start && addr2 < end) ||
 602                 ((addr < start) && (addr2 > end)));
 603 }
 604
 605 static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
 606 {
 607         if (overlap(addr, size, _text, _etext) ||
 608             overlap(addr, size, __start_rodata, __end_rodata))
 609                 err_printk(dev, NULL, "DMA-API: device driver maps "
 610                                 "memory from kernel text or rodata "
 611                                 "[addr=%p] [size=%llu]\n", addr, size);
 612 }
 613
 614 static void check_sync(struct device *dev, dma_addr_t addr,
 615                        u64 size, u64 offset, int direction, bool to_cpu)
 616 {
 617         struct dma_debug_entry ref = {
 618                 .dev            = dev,
 619                 .dev_addr       = addr,
 620                 .size           = size,
 621                 .direction      = direction,
 622         };
 623         struct dma_debug_entry *entry;
 624         struct hash_bucket *bucket;
 625         unsigned long flags;
 626
 627         bucket = get_hash_bucket(&ref, &flags);
 628
 629         entry = hash_bucket_find(bucket, &ref);
 630
 631         if (!entry) {
 632                 err_printk(dev, NULL, "DMA-API: device driver tries "
 633                                 "to sync DMA memory it has not allocated "
 634                                 "[device address=0x%016llx] [size=%llu bytes]\n",
 635                                 (unsigned long long)addr, size);
 636                 goto out;
 637         }
 638
 639         if ((offset + size) > entry->size) {
 640                 err_printk(dev, entry, "DMA-API: device driver syncs"
 641                                 " DMA memory outside allocated range "
 642                                 "[device address=0x%016llx] "
 643                                 "[allocation size=%llu bytes] [sync offset=%llu] "
 644                                 "[sync size=%llu]\n", entry->dev_addr, entry->size,
 645                                 offset, size);
 646         }
 647
 648         if (direction != entry->direction) {
 649                 err_printk(dev, entry, "DMA-API: device driver syncs "
 650                                 "DMA memory with different direction "
 651                                 "[device address=0x%016llx] [size=%llu bytes] "
 652                                 "[mapped with %s] [synced with %s]\n",
 653                                 (unsigned long long)addr, entry->size,
 654                                 dir2name[entry->direction],
 655                                 dir2name[direction]);
 656         }
 657
 658         if (entry->direction == DMA_BIDIRECTIONAL)
 659                 goto out;
 660
 661         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
 662                       !(direction == DMA_TO_DEVICE))
 663                 err_printk(dev, entry, "DMA-API: device driver syncs "
 664                                 "device read-only DMA memory for cpu "
 665                                 "[device address=0x%016llx] [size=%llu bytes] "
 666                                 "[mapped with %s] [synced with %s]\n",
 667                                 (unsigned long long)addr, entry->size,
 668                                 dir2name[entry->direction],
 669                                 dir2name[direction]);
 670
 671         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
 672                        !(direction == DMA_FROM_DEVICE))
 673                 err_printk(dev, entry, "DMA-API: device driver syncs "
 674                                 "device write-only DMA memory to device "
 675                                 "[device address=0x%016llx] [size=%llu bytes] "
 676                                 "[mapped with %s] [synced with %s]\n",
 677                                 (unsigned long long)addr, entry->size,
 678                                 dir2name[entry->direction],
 679                                 dir2name[direction]);
 680
 681 out:
 682         put_hash_bucket(bucket, &flags);
 683
 684 }
 685
 686 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
 687                         size_t size, int direction, dma_addr_t dma_addr,
 688                         bool map_single)
 689 {
 690         struct dma_debug_entry *entry;
 691
 692         if (unlikely(global_disable))
 693                 return;
 694
 695         if (unlikely(dma_mapping_error(dev, dma_addr)))
 696                 return;
 697
 698         entry = dma_entry_alloc();
 699         if (!entry)
 700                 return;
 701
 702         entry->dev       = dev;
 703         entry->type      = dma_debug_page;
 704         entry->paddr     = page_to_phys(page) + offset;
 705         entry->dev_addr  = dma_addr;
 706         entry->size      = size;
 707         entry->direction = direction;
 708
 709         if (map_single)
 710                 entry->type = dma_debug_single;
 711
 712         if (!PageHighMem(page)) {
 713                 void *addr = ((char *)page_address(page)) + offset;
 714                 check_for_stack(dev, addr);
 715                 check_for_illegal_area(dev, addr, size);
 716         }
 717
 718         add_dma_entry(entry);
 719 }
 720 EXPORT_SYMBOL(debug_dma_map_page);
 721
 722 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 723                           size_t size, int direction, bool map_single)
 724 {
 725         struct dma_debug_entry ref = {
 726                 .type           = dma_debug_page,
 727                 .dev            = dev,
 728                 .dev_addr       = addr,
 729                 .size           = size,
 730                 .direction      = direction,
 731         };
 732
 733         if (unlikely(global_disable))
 734                 return;
 735
 736         if (map_single)
 737                 ref.type = dma_debug_single;
 738
 739         check_unmap(&ref);
 740 }
 741 EXPORT_SYMBOL(debug_dma_unmap_page);
 742
 743 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
 744                       int nents, int mapped_ents, int direction)
 745 {
 746         struct dma_debug_entry *entry;
 747         struct scatterlist *s;
 748         int i;
 749
 750         if (unlikely(global_disable))
 751                 return;
 752
 753         for_each_sg(sg, s, mapped_ents, i) {
 754                 entry = dma_entry_alloc();
 755                 if (!entry)
 756                         return;
 757
 758                 entry->type           = dma_debug_sg;
 759                 entry->dev            = dev;
 760                 entry->paddr          = sg_phys(s);
 761                 entry->size           = s->length;
 762                 entry->dev_addr       = s->dma_address;
 763                 entry->direction      = direction;
 764                 entry->sg_call_ents   = nents;
 765                 entry->sg_mapped_ents = mapped_ents;
 766
 767                 if (!PageHighMem(sg_page(s))) {
 768                         check_for_stack(dev, sg_virt(s));
 769                         check_for_illegal_area(dev, sg_virt(s), s->length);
 770                 }
 771
 772                 add_dma_entry(entry);
 773         }
 774 }
 775 EXPORT_SYMBOL(debug_dma_map_sg);
 776
 777 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 778                         int nelems, int dir)
 779 {
 780         struct dma_debug_entry *entry;
 781         struct scatterlist *s;
 782         int mapped_ents = 0, i;
 783         unsigned long flags;
 784
 785         if (unlikely(global_disable))
 786                 return;
 787
 788         for_each_sg(sglist, s, nelems, i) {
 789
 790                 struct dma_debug_entry ref = {
 791                         .type           = dma_debug_sg,
 792                         .dev            = dev,
 793                         .paddr          = sg_phys(s),
 794                         .dev_addr       = s->dma_address,
 795                         .size           = s->length,
 796                         .direction      = dir,
 797                         .sg_call_ents   = 0,
 798                 };
 799
 800                 if (mapped_ents && i >= mapped_ents)
 801                         break;
 802
 803                 if (mapped_ents == 0) {
 804                         struct hash_bucket *bucket;
 805                         ref.sg_call_ents = nelems;
 806                         bucket = get_hash_bucket(&ref, &flags);
 807                         entry = hash_bucket_find(bucket, &ref);
 808                         if (entry)
 809                                 mapped_ents = entry->sg_mapped_ents;
 810                         put_hash_bucket(bucket, &flags);
 811                 }
 812
 813                 check_unmap(&ref);
 814         }
 815 }
 816 EXPORT_SYMBOL(debug_dma_unmap_sg);
 817
 818 void debug_dma_alloc_coherent(struct device *dev, size_t size,
 819                               dma_addr_t dma_addr, void *virt)
 820 {
 821         struct dma_debug_entry *entry;
 822
 823         if (unlikely(global_disable))
 824                 return;
 825
 826         if (unlikely(virt == NULL))
 827                 return;
 828
 829         entry = dma_entry_alloc();
 830         if (!entry)
 831                 return;
 832
 833         entry->type      = dma_debug_coherent;
 834         entry->dev       = dev;
 835         entry->paddr     = virt_to_phys(virt);
 836         entry->size      = size;
 837         entry->dev_addr  = dma_addr;
 838         entry->direction = DMA_BIDIRECTIONAL;
 839
 840         add_dma_entry(entry);
 841 }
 842 EXPORT_SYMBOL(debug_dma_alloc_coherent);
 843
 844 void debug_dma_free_coherent(struct device *dev, size_t size,
 845                          void *virt, dma_addr_t addr)
 846 {
 847         struct dma_debug_entry ref = {
 848                 .type           = dma_debug_coherent,
 849                 .dev            = dev,
 850                 .paddr          = virt_to_phys(virt),
 851                 .dev_addr       = addr,
 852                 .size           = size,
 853                 .direction      = DMA_BIDIRECTIONAL,
 854         };
 855
 856         if (unlikely(global_disable))
 857                 return;
 858
 859         check_unmap(&ref);
 860 }
 861 EXPORT_SYMBOL(debug_dma_free_coherent);
 862
 863 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 864                                    size_t size, int direction)
 865 {
 866         if (unlikely(global_disable))
 867                 return;
 868
 869         check_sync(dev, dma_handle, size, 0, direction, true);
 870 }
 871 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
 872
 873 void debug_dma_sync_single_for_device(struct device *dev,
 874                                       dma_addr_t dma_handle, size_t size,
 875                                       int direction)
 876 {
 877         if (unlikely(global_disable))
 878                 return;
 879
 880         check_sync(dev, dma_handle, size, 0, direction, false);
 881 }
 882 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
 883
 884 void debug_dma_sync_single_range_for_cpu(struct device *dev,
 885                                          dma_addr_t dma_handle,
 886                                          unsigned long offset, size_t size,
 887                                          int direction)
 888 {
 889         if (unlikely(global_disable))
 890                 return;
 891
 892         check_sync(dev, dma_handle, size, offset, direction, true);
 893 }
 894 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
 895
 896 void debug_dma_sync_single_range_for_device(struct device *dev,
 897                                             dma_addr_t dma_handle,
 898                                             unsigned long offset,
 899                                             size_t size, int direction)
 900 {
 901         if (unlikely(global_disable))
 902                 return;
 903
 904         check_sync(dev, dma_handle, size, offset, direction, false);
 905 }
 906 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
 907
 908 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 909                                int nelems, int direction)
 910 {
 911         struct scatterlist *s;
 912         int i;
 913
 914         if (unlikely(global_disable))
 915                 return;
 916
 917         for_each_sg(sg, s, nelems, i) {
 918                 check_sync(dev, s->dma_address, s->dma_length, 0,
 919                                 direction, true);
 920         }
 921 }
 922 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
 923
 924 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 925                                   int nelems, int direction)
 926 {
 927         struct scatterlist *s;
 928         int i;
 929
 930         if (unlikely(global_disable))
 931                 return;
 932
 933         for_each_sg(sg, s, nelems, i) {
 934                 check_sync(dev, s->dma_address, s->dma_length, 0,
 935                                 direction, false);
 936         }
 937 }
 938 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
 939