SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 static u32 nr_total_entries;
  89
  90 /* number of preallocated entries requested by kernel cmdline */
  91 static u32 req_entries;
  92
  93 /* debugfs dentry's for the stuff above */
  94 static struct dentry *dma_debug_dent        __read_mostly;
  95 static struct dentry *global_disable_dent   __read_mostly;
  96 static struct dentry *error_count_dent      __read_mostly;
  97 static struct dentry *show_all_errors_dent  __read_mostly;
  98 static struct dentry *show_num_errors_dent  __read_mostly;
  99 static struct dentry *num_free_entries_dent __read_mostly;
 100 static struct dentry *min_free_entries_dent __read_mostly;
 101
 102 static const char *type2name[4] = { "single", "page",
 103                                     "scather-gather", "coherent" };
 104
 105 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
 106                                    "DMA_FROM_DEVICE", "DMA_NONE" };
 107
 108 /*
 109  * The access to some variables in this macro is racy. We can't use atomic_t
 110  * here because all these variables are exported to debugfs. Some of them even
 111  * writeable. This is also the reason why a lock won't help much. But anyway,
 112  * the races are no big deal. Here is why:
 113  *
 114  *   error_count: the addition is racy, but the worst thing that can happen is
 115  *                that we don't count some errors
 116  *   show_num_errors: the subtraction is racy. Also no big deal because in
 117  *                    worst case this will result in one warning more in the
 118  *                    system log than the user configured. This variable is
 119  *                    writeable via debugfs.
 120  */
 121 static inline void dump_entry_trace(struct dma_debug_entry *entry)
 122 {
 123 #ifdef CONFIG_STACKTRACE
 124         if (entry) {
 125                 printk(KERN_WARNING "Mapped at:\n");
 126                 print_stack_trace(&entry->stacktrace, 0);
 127         }
 128 #endif
 129 }
 130
 131 #define err_printk(dev, entry, format, arg...) do {             \
 132                 error_count += 1;                               \
 133                 if (show_all_errors || show_num_errors > 0) {   \
 134                         WARN(1, "%s %s: " format,               \
 135                              dev_driver_string(dev),            \
 136                              dev_name(dev) , ## arg);           \
 137                         dump_entry_trace(entry);                \
 138                 }                                               \
 139                 if (!show_all_errors && show_num_errors > 0)    \
 140                         show_num_errors -= 1;                   \
 141         } while (0);
 142
 143 /*
 144  * Hash related functions
 145  *
 146  * Every DMA-API request is saved into a struct dma_debug_entry. To
 147  * have quick access to these structs they are stored into a hash.
 148  */
 149 static int hash_fn(struct dma_debug_entry *entry)
 150 {
 151         /*
 152          * Hash function is based on the dma address.
 153          * We use bits 20-27 here as the index into the hash
 154          */
 155         return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
 156 }
 157
 158 /*
 159  * Request exclusive access to a hash bucket for a given dma_debug_entry.
 160  */
 161 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
 162                                            unsigned long *flags)
 163 {
 164         int idx = hash_fn(entry);
 165         unsigned long __flags;
 166
 167         spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
 168         *flags = __flags;
 169         return &dma_entry_hash[idx];
 170 }
 171
 172 /*
 173  * Give up exclusive access to the hash bucket
 174  */
 175 static void put_hash_bucket(struct hash_bucket *bucket,
 176                             unsigned long *flags)
 177 {
 178         unsigned long __flags = *flags;
 179
 180         spin_unlock_irqrestore(&bucket->lock, __flags);
 181 }
 182
 183 /*
 184  * Search a given entry in the hash bucket list
 185  */
 186 static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
 187                                                 struct dma_debug_entry *ref)
 188 {
 189         struct dma_debug_entry *entry;
 190
 191         list_for_each_entry(entry, &bucket->list, list) {
 192                 if ((entry->dev_addr == ref->dev_addr) &&
 193                     (entry->dev == ref->dev))
 194                         return entry;
 195         }
 196
 197         return NULL;
 198 }
 199
 200 /*
 201  * Add an entry to a hash bucket
 202  */
 203 static void hash_bucket_add(struct hash_bucket *bucket,
 204                             struct dma_debug_entry *entry)
 205 {
 206         list_add_tail(&entry->list, &bucket->list);
 207 }
 208
 209 /*
 210  * Remove entry from a hash bucket list
 211  */
 212 static void hash_bucket_del(struct dma_debug_entry *entry)
 213 {
 214         list_del(&entry->list);
 215 }
 216
 217 /*
 218  * Dump mapping entries for debugging purposes
 219  */
 220 void debug_dma_dump_mappings(struct device *dev)
 221 {
 222         int idx;
 223
 224         for (idx = 0; idx < HASH_SIZE; idx++) {
 225                 struct hash_bucket *bucket = &dma_entry_hash[idx];
 226                 struct dma_debug_entry *entry;
 227                 unsigned long flags;
 228
 229                 spin_lock_irqsave(&bucket->lock, flags);
 230
 231                 list_for_each_entry(entry, &bucket->list, list) {
 232                         if (!dev || dev == entry->dev) {
 233                                 dev_info(entry->dev,
 234                                          "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
 235                                          type2name[entry->type], idx,
 236                                          (unsigned long long)entry->paddr,
 237                                          entry->dev_addr, entry->size,
 238                                          dir2name[entry->direction]);
 239                         }
 240                 }
 241
 242                 spin_unlock_irqrestore(&bucket->lock, flags);
 243         }
 244 }
 245 EXPORT_SYMBOL(debug_dma_dump_mappings);
 246
 247 /*
 248  * Wrapper function for adding an entry to the hash.
 249  * This function takes care of locking itself.
 250  */
 251 static void add_dma_entry(struct dma_debug_entry *entry)
 252 {
 253         struct hash_bucket *bucket;
 254         unsigned long flags;
 255
 256         bucket = get_hash_bucket(entry, &flags);
 257         hash_bucket_add(bucket, entry);
 258         put_hash_bucket(bucket, &flags);
 259 }
 260
 261 static struct dma_debug_entry *__dma_entry_alloc(void)
 262 {
 263         struct dma_debug_entry *entry;
 264
 265         entry = list_entry(free_entries.next, struct dma_debug_entry, list);
 266         list_del(&entry->list);
 267         memset(entry, 0, sizeof(*entry));
 268
 269         num_free_entries -= 1;
 270         if (num_free_entries < min_free_entries)
 271                 min_free_entries = num_free_entries;
 272
 273         return entry;
 274 }
 275
 276 /* struct dma_entry allocator
 277  *
 278  * The next two functions implement the allocator for
 279  * struct dma_debug_entries.
 280  */
 281 static struct dma_debug_entry *dma_entry_alloc(void)
 282 {
 283         struct dma_debug_entry *entry = NULL;
 284         unsigned long flags;
 285
 286         spin_lock_irqsave(&free_entries_lock, flags);
 287
 288         if (list_empty(&free_entries)) {
 289                 printk(KERN_ERR "DMA-API: debugging out of memory "
 290                                 "- disabling\n");
 291                 global_disable = true;
 292                 goto out;
 293         }
 294
 295         entry = __dma_entry_alloc();
 296
 297 #ifdef CONFIG_STACKTRACE
 298         entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
 299         entry->stacktrace.entries = entry->st_entries;
 300         entry->stacktrace.skip = 2;
 301         save_stack_trace(&entry->stacktrace);
 302 #endif
 303
 304 out:
 305         spin_unlock_irqrestore(&free_entries_lock, flags);
 306
 307         return entry;
 308 }
 309
 310 static void dma_entry_free(struct dma_debug_entry *entry)
 311 {
 312         unsigned long flags;
 313
 314         /*
 315          * add to beginning of the list - this way the entries are
 316          * more likely cache hot when they are reallocated.
 317          */
 318         spin_lock_irqsave(&free_entries_lock, flags);
 319         list_add(&entry->list, &free_entries);
 320         num_free_entries += 1;
 321         spin_unlock_irqrestore(&free_entries_lock, flags);
 322 }
 323
 324 int dma_debug_resize_entries(u32 num_entries)
 325 {
 326         int i, delta, ret = 0;
 327         unsigned long flags;
 328         struct dma_debug_entry *entry;
 329         LIST_HEAD(tmp);
 330
 331         spin_lock_irqsave(&free_entries_lock, flags);
 332
 333         if (nr_total_entries < num_entries) {
 334                 delta = num_entries - nr_total_entries;
 335
 336                 spin_unlock_irqrestore(&free_entries_lock, flags);
 337
 338                 for (i = 0; i < delta; i++) {
 339                         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 340                         if (!entry)
 341                                 break;
 342
 343                         list_add_tail(&entry->list, &tmp);
 344                 }
 345
 346                 spin_lock_irqsave(&free_entries_lock, flags);
 347
 348                 list_splice(&tmp, &free_entries);
 349                 nr_total_entries += i;
 350                 num_free_entries += i;
 351         } else {
 352                 delta = nr_total_entries - num_entries;
 353
 354                 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
 355                         entry = __dma_entry_alloc();
 356                         kfree(entry);
 357                 }
 358
 359                 nr_total_entries -= i;
 360         }
 361
 362         if (nr_total_entries != num_entries)
 363                 ret = 1;
 364
 365         spin_unlock_irqrestore(&free_entries_lock, flags);
 366
 367         return ret;
 368 }
 369 EXPORT_SYMBOL(dma_debug_resize_entries);
 370
 371 /*
 372  * DMA-API debugging init code
 373  *
 374  * The init code does two things:
 375  *   1. Initialize core data structures
 376  *   2. Preallocate a given number of dma_debug_entry structs
 377  */
 378
 379 static int prealloc_memory(u32 num_entries)
 380 {
 381         struct dma_debug_entry *entry, *next_entry;
 382         int i;
 383
 384         for (i = 0; i < num_entries; ++i) {
 385                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 386                 if (!entry)
 387                         goto out_err;
 388
 389                 list_add_tail(&entry->list, &free_entries);
 390         }
 391
 392         num_free_entries = num_entries;
 393         min_free_entries = num_entries;
 394
 395         printk(KERN_INFO "DMA-API: preallocated %d debug entries\n",
 396                         num_entries);
 397
 398         return 0;
 399
 400 out_err:
 401
 402         list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
 403                 list_del(&entry->list);
 404                 kfree(entry);
 405         }
 406
 407         return -ENOMEM;
 408 }
 409
 410 static int dma_debug_fs_init(void)
 411 {
 412         dma_debug_dent = debugfs_create_dir("dma-api", NULL);
 413         if (!dma_debug_dent) {
 414                 printk(KERN_ERR "DMA-API: can not create debugfs directory\n");
 415                 return -ENOMEM;
 416         }
 417
 418         global_disable_dent = debugfs_create_bool("disabled", 0444,
 419                         dma_debug_dent,
 420                         (u32 *)&global_disable);
 421         if (!global_disable_dent)
 422                 goto out_err;
 423
 424         error_count_dent = debugfs_create_u32("error_count", 0444,
 425                         dma_debug_dent, &error_count);
 426         if (!error_count_dent)
 427                 goto out_err;
 428
 429         show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
 430                         dma_debug_dent,
 431                         &show_all_errors);
 432         if (!show_all_errors_dent)
 433                 goto out_err;
 434
 435         show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
 436                         dma_debug_dent,
 437                         &show_num_errors);
 438         if (!show_num_errors_dent)
 439                 goto out_err;
 440
 441         num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
 442                         dma_debug_dent,
 443                         &num_free_entries);
 444         if (!num_free_entries_dent)
 445                 goto out_err;
 446
 447         min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
 448                         dma_debug_dent,
 449                         &min_free_entries);
 450         if (!min_free_entries_dent)
 451                 goto out_err;
 452
 453         return 0;
 454
 455 out_err:
 456         debugfs_remove_recursive(dma_debug_dent);
 457
 458         return -ENOMEM;
 459 }
 460
 461 void dma_debug_add_bus(struct bus_type *bus)
 462 {
 463         /* FIXME: register notifier */
 464 }
 465
 466 /*
 467  * Let the architectures decide how many entries should be preallocated.
 468  */
 469 void dma_debug_init(u32 num_entries)
 470 {
 471         int i;
 472
 473         if (global_disable)
 474                 return;
 475
 476         for (i = 0; i < HASH_SIZE; ++i) {
 477                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
 478                 dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
 479         }
 480
 481         if (dma_debug_fs_init() != 0) {
 482                 printk(KERN_ERR "DMA-API: error creating debugfs entries "
 483                                 "- disabling\n");
 484                 global_disable = true;
 485
 486                 return;
 487         }
 488
 489         if (req_entries)
 490                 num_entries = req_entries;
 491
 492         if (prealloc_memory(num_entries) != 0) {
 493                 printk(KERN_ERR "DMA-API: debugging out of memory error "
 494                                 "- disabled\n");
 495                 global_disable = true;
 496
 497                 return;
 498         }
 499
 500         nr_total_entries = num_free_entries;
 501
 502         printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
 503 }
 504
 505 static __init int dma_debug_cmdline(char *str)
 506 {
 507         if (!str)
 508                 return -EINVAL;
 509
 510         if (strncmp(str, "off", 3) == 0) {
 511                 printk(KERN_INFO "DMA-API: debugging disabled on kernel "
 512                                  "command line\n");
 513                 global_disable = true;
 514         }
 515
 516         return 0;
 517 }
 518
 519 static __init int dma_debug_entries_cmdline(char *str)
 520 {
 521         int res;
 522
 523         if (!str)
 524                 return -EINVAL;
 525
 526         res = get_option(&str, &req_entries);
 527
 528         if (!res)
 529                 req_entries = 0;
 530
 531         return 0;
 532 }
 533
 534 __setup("dma_debug=", dma_debug_cmdline);
 535 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
 536
 537 static void check_unmap(struct dma_debug_entry *ref)
 538 {
 539         struct dma_debug_entry *entry;
 540         struct hash_bucket *bucket;
 541         unsigned long flags;
 542
 543         if (dma_mapping_error(ref->dev, ref->dev_addr)) {
 544                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
 545                            "to free an invalid DMA memory address\n");
 546                 return;
 547         }
 548
 549         bucket = get_hash_bucket(ref, &flags);
 550         entry = hash_bucket_find(bucket, ref);
 551
 552         if (!entry) {
 553                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
 554                            "to free DMA memory it has not allocated "
 555                            "[device address=0x%016llx] [size=%llu bytes]\n",
 556                            ref->dev_addr, ref->size);
 557                 goto out;
 558         }
 559
 560         if (ref->size != entry->size) {
 561                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 562                            "DMA memory with different size "
 563                            "[device address=0x%016llx] [map size=%llu bytes] "
 564                            "[unmap size=%llu bytes]\n",
 565                            ref->dev_addr, entry->size, ref->size);
 566         }
 567
 568         if (ref->type != entry->type) {
 569                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 570                            "DMA memory with wrong function "
 571                            "[device address=0x%016llx] [size=%llu bytes] "
 572                            "[mapped as %s] [unmapped as %s]\n",
 573                            ref->dev_addr, ref->size,
 574                            type2name[entry->type], type2name[ref->type]);
 575         } else if ((entry->type == dma_debug_coherent) &&
 576                    (ref->paddr != entry->paddr)) {
 577                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 578                            "DMA memory with different CPU address "
 579                            "[device address=0x%016llx] [size=%llu bytes] "
 580                            "[cpu alloc address=%p] [cpu free address=%p]",
 581                            ref->dev_addr, ref->size,
 582                            (void *)entry->paddr, (void *)ref->paddr);
 583         }
 584
 585         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
 586             ref->sg_call_ents != entry->sg_call_ents) {
 587                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 588                            "DMA sg list with different entry count "
 589                            "[map count=%d] [unmap count=%d]\n",
 590                            entry->sg_call_ents, ref->sg_call_ents);
 591         }
 592
 593         /*
 594          * This may be no bug in reality - but most implementations of the
 595          * DMA API don't handle this properly, so check for it here
 596          */
 597         if (ref->direction != entry->direction) {
 598                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
 599                            "DMA memory with different direction "
 600                            "[device address=0x%016llx] [size=%llu bytes] "
 601                            "[mapped with %s] [unmapped with %s]\n",
 602                            ref->dev_addr, ref->size,
 603                            dir2name[entry->direction],
 604                            dir2name[ref->direction]);
 605         }
 606
 607         hash_bucket_del(entry);
 608         dma_entry_free(entry);
 609
 610 out:
 611         put_hash_bucket(bucket, &flags);
 612 }
 613
 614 static void check_for_stack(struct device *dev, void *addr)
 615 {
 616         if (object_is_on_stack(addr))
 617                 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
 618                                 "stack [addr=%p]\n", addr);
 619 }
 620
 621 static inline bool overlap(void *addr, u64 size, void *start, void *end)
 622 {
 623         void *addr2 = (char *)addr + size;
 624
 625         return ((addr >= start && addr < end) ||
 626                 (addr2 >= start && addr2 < end) ||
 627                 ((addr < start) && (addr2 >= end)));
 628 }
 629
 630 static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
 631 {
 632         if (overlap(addr, size, _text, _etext) ||
 633             overlap(addr, size, __start_rodata, __end_rodata))
 634                 err_printk(dev, NULL, "DMA-API: device driver maps "
 635                                 "memory from kernel text or rodata "
 636                                 "[addr=%p] [size=%llu]\n", addr, size);
 637 }
 638
 639 static void check_sync(struct device *dev, dma_addr_t addr,
 640                        u64 size, u64 offset, int direction, bool to_cpu)
 641 {
 642         struct dma_debug_entry ref = {
 643                 .dev            = dev,
 644                 .dev_addr       = addr,
 645                 .size           = size,
 646                 .direction      = direction,
 647         };
 648         struct dma_debug_entry *entry;
 649         struct hash_bucket *bucket;
 650         unsigned long flags;
 651
 652         bucket = get_hash_bucket(&ref, &flags);
 653
 654         entry = hash_bucket_find(bucket, &ref);
 655
 656         if (!entry) {
 657                 err_printk(dev, NULL, "DMA-API: device driver tries "
 658                                 "to sync DMA memory it has not allocated "
 659                                 "[device address=0x%016llx] [size=%llu bytes]\n",
 660                                 (unsigned long long)addr, size);
 661                 goto out;
 662         }
 663
 664         if ((offset + size) > entry->size) {
 665                 err_printk(dev, entry, "DMA-API: device driver syncs"
 666                                 " DMA memory outside allocated range "
 667                                 "[device address=0x%016llx] "
 668                                 "[allocation size=%llu bytes] [sync offset=%llu] "
 669                                 "[sync size=%llu]\n", entry->dev_addr, entry->size,
 670                                 offset, size);
 671         }
 672
 673         if (direction != entry->direction) {
 674                 err_printk(dev, entry, "DMA-API: device driver syncs "
 675                                 "DMA memory with different direction "
 676                                 "[device address=0x%016llx] [size=%llu bytes] "
 677                                 "[mapped with %s] [synced with %s]\n",
 678                                 (unsigned long long)addr, entry->size,
 679                                 dir2name[entry->direction],
 680                                 dir2name[direction]);
 681         }
 682
 683         if (entry->direction == DMA_BIDIRECTIONAL)
 684                 goto out;
 685
 686         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
 687                       !(direction == DMA_TO_DEVICE))
 688                 err_printk(dev, entry, "DMA-API: device driver syncs "
 689                                 "device read-only DMA memory for cpu "
 690                                 "[device address=0x%016llx] [size=%llu bytes] "
 691                                 "[mapped with %s] [synced with %s]\n",
 692                                 (unsigned long long)addr, entry->size,
 693                                 dir2name[entry->direction],
 694                                 dir2name[direction]);
 695
 696         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
 697                        !(direction == DMA_FROM_DEVICE))
 698                 err_printk(dev, entry, "DMA-API: device driver syncs "
 699                                 "device write-only DMA memory to device "
 700                                 "[device address=0x%016llx] [size=%llu bytes] "
 701                                 "[mapped with %s] [synced with %s]\n",
 702                                 (unsigned long long)addr, entry->size,
 703                                 dir2name[entry->direction],
 704                                 dir2name[direction]);
 705
 706 out:
 707         put_hash_bucket(bucket, &flags);
 708
 709 }
 710
 711 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
 712                         size_t size, int direction, dma_addr_t dma_addr,
 713                         bool map_single)
 714 {
 715         struct dma_debug_entry *entry;
 716
 717         if (unlikely(global_disable))
 718                 return;
 719
 720         if (unlikely(dma_mapping_error(dev, dma_addr)))
 721                 return;
 722
 723         entry = dma_entry_alloc();
 724         if (!entry)
 725                 return;
 726
 727         entry->dev       = dev;
 728         entry->type      = dma_debug_page;
 729         entry->paddr     = page_to_phys(page) + offset;
 730         entry->dev_addr  = dma_addr;
 731         entry->size      = size;
 732         entry->direction = direction;
 733
 734         if (map_single)
 735                 entry->type = dma_debug_single;
 736
 737         if (!PageHighMem(page)) {
 738                 void *addr = ((char *)page_address(page)) + offset;
 739                 check_for_stack(dev, addr);
 740                 check_for_illegal_area(dev, addr, size);
 741         }
 742
 743         add_dma_entry(entry);
 744 }
 745 EXPORT_SYMBOL(debug_dma_map_page);
 746
 747 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 748                           size_t size, int direction, bool map_single)
 749 {
 750         struct dma_debug_entry ref = {
 751                 .type           = dma_debug_page,
 752                 .dev            = dev,
 753                 .dev_addr       = addr,
 754                 .size           = size,
 755                 .direction      = direction,
 756         };
 757
 758         if (unlikely(global_disable))
 759                 return;
 760
 761         if (map_single)
 762                 ref.type = dma_debug_single;
 763
 764         check_unmap(&ref);
 765 }
 766 EXPORT_SYMBOL(debug_dma_unmap_page);
 767
 768 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
 769                       int nents, int mapped_ents, int direction)
 770 {
 771         struct dma_debug_entry *entry;
 772         struct scatterlist *s;
 773         int i;
 774
 775         if (unlikely(global_disable))
 776                 return;
 777
 778         for_each_sg(sg, s, mapped_ents, i) {
 779                 entry = dma_entry_alloc();
 780                 if (!entry)
 781                         return;
 782
 783                 entry->type           = dma_debug_sg;
 784                 entry->dev            = dev;
 785                 entry->paddr          = sg_phys(s);
 786                 entry->size           = s->length;
 787                 entry->dev_addr       = s->dma_address;
 788                 entry->direction      = direction;
 789                 entry->sg_call_ents   = nents;
 790                 entry->sg_mapped_ents = mapped_ents;
 791
 792                 if (!PageHighMem(sg_page(s))) {
 793                         check_for_stack(dev, sg_virt(s));
 794                         check_for_illegal_area(dev, sg_virt(s), s->length);
 795                 }
 796
 797                 add_dma_entry(entry);
 798         }
 799 }
 800 EXPORT_SYMBOL(debug_dma_map_sg);
 801
 802 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 803                         int nelems, int dir)
 804 {
 805         struct dma_debug_entry *entry;
 806         struct scatterlist *s;
 807         int mapped_ents = 0, i;
 808         unsigned long flags;
 809
 810         if (unlikely(global_disable))
 811                 return;
 812
 813         for_each_sg(sglist, s, nelems, i) {
 814
 815                 struct dma_debug_entry ref = {
 816                         .type           = dma_debug_sg,
 817                         .dev            = dev,
 818                         .paddr          = sg_phys(s),
 819                         .dev_addr       = s->dma_address,
 820                         .size           = s->length,
 821                         .direction      = dir,
 822                         .sg_call_ents   = 0,
 823                 };
 824
 825                 if (mapped_ents && i >= mapped_ents)
 826                         break;
 827
 828                 if (mapped_ents == 0) {
 829                         struct hash_bucket *bucket;
 830                         ref.sg_call_ents = nelems;
 831                         bucket = get_hash_bucket(&ref, &flags);
 832                         entry = hash_bucket_find(bucket, &ref);
 833                         if (entry)
 834                                 mapped_ents = entry->sg_mapped_ents;
 835                         put_hash_bucket(bucket, &flags);
 836                 }
 837
 838                 check_unmap(&ref);
 839         }
 840 }
 841 EXPORT_SYMBOL(debug_dma_unmap_sg);
 842
 843 void debug_dma_alloc_coherent(struct device *dev, size_t size,
 844                               dma_addr_t dma_addr, void *virt)
 845 {
 846         struct dma_debug_entry *entry;
 847
 848         if (unlikely(global_disable))
 849                 return;
 850
 851         if (unlikely(virt == NULL))
 852                 return;
 853
 854         entry = dma_entry_alloc();
 855         if (!entry)
 856                 return;
 857
 858         entry->type      = dma_debug_coherent;
 859         entry->dev       = dev;
 860         entry->paddr     = virt_to_phys(virt);
 861         entry->size      = size;
 862         entry->dev_addr  = dma_addr;
 863         entry->direction = DMA_BIDIRECTIONAL;
 864
 865         add_dma_entry(entry);
 866 }
 867 EXPORT_SYMBOL(debug_dma_alloc_coherent);
 868
 869 void debug_dma_free_coherent(struct device *dev, size_t size,
 870                          void *virt, dma_addr_t addr)
 871 {
 872         struct dma_debug_entry ref = {
 873                 .type           = dma_debug_coherent,
 874                 .dev            = dev,
 875                 .paddr          = virt_to_phys(virt),
 876                 .dev_addr       = addr,
 877                 .size           = size,
 878                 .direction      = DMA_BIDIRECTIONAL,
 879         };
 880
 881         if (unlikely(global_disable))
 882                 return;
 883
 884         check_unmap(&ref);
 885 }
 886 EXPORT_SYMBOL(debug_dma_free_coherent);
 887
 888 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 889                                    size_t size, int direction)
 890 {
 891         if (unlikely(global_disable))
 892                 return;
 893
 894         check_sync(dev, dma_handle, size, 0, direction, true);
 895 }
 896 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
 897
 898 void debug_dma_sync_single_for_device(struct device *dev,
 899                                       dma_addr_t dma_handle, size_t size,
 900                                       int direction)
 901 {
 902         if (unlikely(global_disable))
 903                 return;
 904
 905         check_sync(dev, dma_handle, size, 0, direction, false);
 906 }
 907 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
 908
 909 void debug_dma_sync_single_range_for_cpu(struct device *dev,
 910                                          dma_addr_t dma_handle,
 911                                          unsigned long offset, size_t size,
 912                                          int direction)
 913 {
 914         if (unlikely(global_disable))
 915                 return;
 916
 917         check_sync(dev, dma_handle, size, offset, direction, true);
 918 }
 919 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
 920
 921 void debug_dma_sync_single_range_for_device(struct device *dev,
 922                                             dma_addr_t dma_handle,
 923                                             unsigned long offset,
 924                                             size_t size, int direction)
 925 {
 926         if (unlikely(global_disable))
 927                 return;
 928
 929         check_sync(dev, dma_handle, size, offset, direction, false);
 930 }
 931 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
 932
 933 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 934                                int nelems, int direction)
 935 {
 936         struct scatterlist *s;
 937         int i;
 938
 939         if (unlikely(global_disable))
 940                 return;
 941
 942         for_each_sg(sg, s, nelems, i) {
 943                 check_sync(dev, s->dma_address, s->dma_length, 0,
 944                                 direction, true);
 945         }
 946 }
 947 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
 948
 949 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 950                                   int nelems, int direction)
 951 {
 952         struct scatterlist *s;
 953         int i;
 954
 955         if (unlikely(global_disable))
 956                 return;
 957
 958         for_each_sg(sg, s, nelems, i) {
 959                 check_sync(dev, s->dma_address, s->dma_length, 0,
 960                                 direction, false);
 961         }
 962 }
 963 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
 964