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