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/uaccess.h>
  27 #include <linux/export.h>
  28 #include <linux/device.h>
  29 #include <linux/types.h>
  30 #include <linux/sched.h>
  31 #include <linux/ctype.h>
  32 #include <linux/list.h>
  33 #include <linux/slab.h>
  34
  35 #include <asm/sections.h>
  36
  37 #define HASH_SIZE       1024ULL
  38 #define HASH_FN_SHIFT   13
  39 #define HASH_FN_MASK    (HASH_SIZE - 1)
  40
  41 enum {
  42         dma_debug_single,
  43         dma_debug_page,
  44         dma_debug_sg,
  45         dma_debug_coherent,
  46         dma_debug_resource,
  47 };
  48
  49 enum map_err_types {
  50         MAP_ERR_CHECK_NOT_APPLICABLE,
  51         MAP_ERR_NOT_CHECKED,
  52         MAP_ERR_CHECKED,
  53 };
  54
  55 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
  56
  57 /**
  58  * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
  59  * @list: node on pre-allocated free_entries list
  60  * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
  61  * @type: single, page, sg, coherent
  62  * @pfn: page frame of the start address
  63  * @offset: offset of mapping relative to pfn
  64  * @size: length of the mapping
  65  * @direction: enum dma_data_direction
  66  * @sg_call_ents: 'nents' from dma_map_sg
  67  * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
  68  * @map_err_type: track whether dma_mapping_error() was checked
  69  * @stacktrace: support backtraces when a violation is detected
  70  */
  71 struct dma_debug_entry {
  72         struct list_head list;
  73         struct device    *dev;
  74         int              type;
  75         unsigned long    pfn;
  76         size_t           offset;
  77         u64              dev_addr;
  78         u64              size;
  79         int              direction;
  80         int              sg_call_ents;
  81         int              sg_mapped_ents;
  82         enum map_err_types  map_err_type;
  83 #ifdef CONFIG_STACKTRACE
  84         struct           stack_trace stacktrace;
  85         unsigned long    st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
  86 #endif
  87 };
  88
  89 typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
  90
  91 struct hash_bucket {
  92         struct list_head list;
  93         spinlock_t lock;
  94 } ____cacheline_aligned_in_smp;
  95
  96 /* Hash list to save the allocated dma addresses */
  97 static struct hash_bucket dma_entry_hash[HASH_SIZE];
  98 /* List of pre-allocated dma_debug_entry's */
  99 static LIST_HEAD(free_entries);
 100 /* Lock for the list above */
 101 static DEFINE_SPINLOCK(free_entries_lock);
 102
 103 /* Global disable flag - will be set in case of an error */
 104 static bool global_disable __read_mostly;
 105
 106 /* Early initialization disable flag, set at the end of dma_debug_init */
 107 static bool dma_debug_initialized __read_mostly;
 108
 109 static inline bool dma_debug_disabled(void)
 110 {
 111         return global_disable || !dma_debug_initialized;
 112 }
 113
 114 /* Global error count */
 115 static u32 error_count;
 116
 117 /* Global error show enable*/
 118 static u32 show_all_errors __read_mostly;
 119 /* Number of errors to show */
 120 static u32 show_num_errors = 1;
 121
 122 static u32 num_free_entries;
 123 static u32 min_free_entries;
 124 static u32 nr_total_entries;
 125
 126 /* number of preallocated entries requested by kernel cmdline */
 127 static u32 req_entries;
 128
 129 /* debugfs dentry's for the stuff above */
 130 static struct dentry *dma_debug_dent        __read_mostly;
 131 static struct dentry *global_disable_dent   __read_mostly;
 132 static struct dentry *error_count_dent      __read_mostly;
 133 static struct dentry *show_all_errors_dent  __read_mostly;
 134 static struct dentry *show_num_errors_dent  __read_mostly;
 135 static struct dentry *num_free_entries_dent __read_mostly;
 136 static struct dentry *min_free_entries_dent __read_mostly;
 137 static struct dentry *filter_dent           __read_mostly;
 138
 139 /* per-driver filter related state */
 140
 141 #define NAME_MAX_LEN    64
 142
 143 static char                  current_driver_name[NAME_MAX_LEN] __read_mostly;
 144 static struct device_driver *current_driver                    __read_mostly;
 145
 146 static DEFINE_RWLOCK(driver_name_lock);
 147
 148 static const char *const maperr2str[] = {
 149         [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
 150         [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
 151         [MAP_ERR_CHECKED] = "dma map error checked",
 152 };
 153
 154 static const char *type2name[5] = { "single", "page",
 155                                     "scather-gather", "coherent",
 156                                     "resource" };
 157
 158 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
 159                                    "DMA_FROM_DEVICE", "DMA_NONE" };
 160
 161 /*
 162  * The access to some variables in this macro is racy. We can't use atomic_t
 163  * here because all these variables are exported to debugfs. Some of them even
 164  * writeable. This is also the reason why a lock won't help much. But anyway,
 165  * the races are no big deal. Here is why:
 166  *
 167  *   error_count: the addition is racy, but the worst thing that can happen is
 168  *                that we don't count some errors
 169  *   show_num_errors: the subtraction is racy. Also no big deal because in
 170  *                    worst case this will result in one warning more in the
 171  *                    system log than the user configured. This variable is
 172  *                    writeable via debugfs.
 173  */
 174 static inline void dump_entry_trace(struct dma_debug_entry *entry)
 175 {
 176 #ifdef CONFIG_STACKTRACE
 177         if (entry) {
 178                 pr_warning("Mapped at:\n");
 179                 print_stack_trace(&entry->stacktrace, 0);
 180         }
 181 #endif
 182 }
 183
 184 static bool driver_filter(struct device *dev)
 185 {
 186         struct device_driver *drv;
 187         unsigned long flags;
 188         bool ret;
 189
 190         /* driver filter off */
 191         if (likely(!current_driver_name[0]))
 192                 return true;
 193
 194         /* driver filter on and initialized */
 195         if (current_driver && dev && dev->driver == current_driver)
 196                 return true;
 197
 198         /* driver filter on, but we can't filter on a NULL device... */
 199         if (!dev)
 200                 return false;
 201
 202         if (current_driver || !current_driver_name[0])
 203                 return false;
 204
 205         /* driver filter on but not yet initialized */
 206         drv = dev->driver;
 207         if (!drv)
 208                 return false;
 209
 210         /* lock to protect against change of current_driver_name */
 211         read_lock_irqsave(&driver_name_lock, flags);
 212
 213         ret = false;
 214         if (drv->name &&
 215             strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
 216                 current_driver = drv;
 217                 ret = true;
 218         }
 219
 220         read_unlock_irqrestore(&driver_name_lock, flags);
 221
 222         return ret;
 223 }
 224
 225 #define err_printk(dev, entry, format, arg...) do {                     \
 226                 error_count += 1;                                       \
 227                 if (driver_filter(dev) &&                               \
 228                     (show_all_errors || show_num_errors > 0)) {         \
 229                         WARN(1, "%s %s: " format,                       \
 230                              dev ? dev_driver_string(dev) : "NULL",     \
 231                              dev ? dev_name(dev) : "NULL", ## arg);     \
 232                         dump_entry_trace(entry);                        \
 233                 }                                                       \
 234                 if (!show_all_errors && show_num_errors > 0)            \
 235                         show_num_errors -= 1;                           \
 236         } while (0);
 237
 238 /*
 239  * Hash related functions
 240  *
 241  * Every DMA-API request is saved into a struct dma_debug_entry. To
 242  * have quick access to these structs they are stored into a hash.
 243  */
 244 static int hash_fn(struct dma_debug_entry *entry)
 245 {
 246         /*
 247          * Hash function is based on the dma address.
 248          * We use bits 20-27 here as the index into the hash
 249          */
 250         return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
 251 }
 252
 253 /*
 254  * Request exclusive access to a hash bucket for a given dma_debug_entry.
 255  */
 256 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
 257                                            unsigned long *flags)
 258         __acquires(&dma_entry_hash[idx].lock)
 259 {
 260         int idx = hash_fn(entry);
 261         unsigned long __flags;
 262
 263         spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
 264         *flags = __flags;
 265         return &dma_entry_hash[idx];
 266 }
 267
 268 /*
 269  * Give up exclusive access to the hash bucket
 270  */
 271 static void put_hash_bucket(struct hash_bucket *bucket,
 272                             unsigned long *flags)
 273         __releases(&bucket->lock)
 274 {
 275         unsigned long __flags = *flags;
 276
 277         spin_unlock_irqrestore(&bucket->lock, __flags);
 278 }
 279
 280 static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
 281 {
 282         return ((a->dev_addr == b->dev_addr) &&
 283                 (a->dev == b->dev)) ? true : false;
 284 }
 285
 286 static bool containing_match(struct dma_debug_entry *a,
 287                              struct dma_debug_entry *b)
 288 {
 289         if (a->dev != b->dev)
 290                 return false;
 291
 292         if ((b->dev_addr <= a->dev_addr) &&
 293             ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
 294                 return true;
 295
 296         return false;
 297 }
 298
 299 /*
 300  * Search a given entry in the hash bucket list
 301  */
 302 static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
 303                                                   struct dma_debug_entry *ref,
 304                                                   match_fn match)
 305 {
 306         struct dma_debug_entry *entry, *ret = NULL;
 307         int matches = 0, match_lvl, last_lvl = -1;
 308
 309         list_for_each_entry(entry, &bucket->list, list) {
 310                 if (!match(ref, entry))
 311                         continue;
 312
 313                 /*
 314                  * Some drivers map the same physical address multiple
 315                  * times. Without a hardware IOMMU this results in the
 316                  * same device addresses being put into the dma-debug
 317                  * hash multiple times too. This can result in false
 318                  * positives being reported. Therefore we implement a
 319                  * best-fit algorithm here which returns the entry from
 320                  * the hash which fits best to the reference value
 321                  * instead of the first-fit.
 322                  */
 323                 matches += 1;
 324                 match_lvl = 0;
 325                 entry->size         == ref->size         ? ++match_lvl : 0;
 326                 entry->type         == ref->type         ? ++match_lvl : 0;
 327                 entry->direction    == ref->direction    ? ++match_lvl : 0;
 328                 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
 329
 330                 if (match_lvl == 4) {
 331                         /* perfect-fit - return the result */
 332                         return entry;
 333                 } else if (match_lvl > last_lvl) {
 334                         /*
 335                          * We found an entry that fits better then the
 336                          * previous one or it is the 1st match.
 337                          */
 338                         last_lvl = match_lvl;
 339                         ret      = entry;
 340                 }
 341         }
 342
 343         /*
 344          * If we have multiple matches but no perfect-fit, just return
 345          * NULL.
 346          */
 347         ret = (matches == 1) ? ret : NULL;
 348
 349         return ret;
 350 }
 351
 352 static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
 353                                                  struct dma_debug_entry *ref)
 354 {
 355         return __hash_bucket_find(bucket, ref, exact_match);
 356 }
 357
 358 static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
 359                                                    struct dma_debug_entry *ref,
 360                                                    unsigned long *flags)
 361 {
 362
 363         unsigned int max_range = dma_get_max_seg_size(ref->dev);
 364         struct dma_debug_entry *entry, index = *ref;
 365         unsigned int range = 0;
 366
 367         while (range <= max_range) {
 368                 entry = __hash_bucket_find(*bucket, ref, containing_match);
 369
 370                 if (entry)
 371                         return entry;
 372
 373                 /*
 374                  * Nothing found, go back a hash bucket
 375                  */
 376                 put_hash_bucket(*bucket, flags);
 377                 range          += (1 << HASH_FN_SHIFT);
 378                 index.dev_addr -= (1 << HASH_FN_SHIFT);
 379                 *bucket = get_hash_bucket(&index, flags);
 380         }
 381
 382         return NULL;
 383 }
 384
 385 /*
 386  * Add an entry to a hash bucket
 387  */
 388 static void hash_bucket_add(struct hash_bucket *bucket,
 389                             struct dma_debug_entry *entry)
 390 {
 391         list_add_tail(&entry->list, &bucket->list);
 392 }
 393
 394 /*
 395  * Remove entry from a hash bucket list
 396  */
 397 static void hash_bucket_del(struct dma_debug_entry *entry)
 398 {
 399         list_del(&entry->list);
 400 }
 401
 402 static unsigned long long phys_addr(struct dma_debug_entry *entry)
 403 {
 404         if (entry->type == dma_debug_resource)
 405                 return __pfn_to_phys(entry->pfn) + entry->offset;
 406
 407         return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
 408 }
 409
 410 /*
 411  * Dump mapping entries for debugging purposes
 412  */
 413 void debug_dma_dump_mappings(struct device *dev)
 414 {
 415         int idx;
 416
 417         for (idx = 0; idx < HASH_SIZE; idx++) {
 418                 struct hash_bucket *bucket = &dma_entry_hash[idx];
 419                 struct dma_debug_entry *entry;
 420                 unsigned long flags;
 421
 422                 spin_lock_irqsave(&bucket->lock, flags);
 423
 424                 list_for_each_entry(entry, &bucket->list, list) {
 425                         if (!dev || dev == entry->dev) {
 426                                 dev_info(entry->dev,
 427                                          "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
 428                                          type2name[entry->type], idx,
 429                                          phys_addr(entry), entry->pfn,
 430                                          entry->dev_addr, entry->size,
 431                                          dir2name[entry->direction],
 432                                          maperr2str[entry->map_err_type]);
 433                         }
 434                 }
 435
 436                 spin_unlock_irqrestore(&bucket->lock, flags);
 437         }
 438 }
 439 EXPORT_SYMBOL(debug_dma_dump_mappings);
 440
 441 /*
 442  * For each mapping (initial cacheline in the case of
 443  * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
 444  * scatterlist, or the cacheline specified in dma_map_single) insert
 445  * into this tree using the cacheline as the key. At
 446  * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry.  If
 447  * the entry already exists at insertion time add a tag as a reference
 448  * count for the overlapping mappings.  For now, the overlap tracking
 449  * just ensures that 'unmaps' balance 'maps' before marking the
 450  * cacheline idle, but we should also be flagging overlaps as an API
 451  * violation.
 452  *
 453  * Memory usage is mostly constrained by the maximum number of available
 454  * dma-debug entries in that we need a free dma_debug_entry before
 455  * inserting into the tree.  In the case of dma_map_page and
 456  * dma_alloc_coherent there is only one dma_debug_entry and one
 457  * dma_active_cacheline entry to track per event.  dma_map_sg(), on the
 458  * other hand, consumes a single dma_debug_entry, but inserts 'nents'
 459  * entries into the tree.
 460  *
 461  * At any time debug_dma_assert_idle() can be called to trigger a
 462  * warning if any cachelines in the given page are in the active set.
 463  */
 464 static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
 465 static DEFINE_SPINLOCK(radix_lock);
 466 #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
 467 #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
 468 #define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
 469
 470 static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
 471 {
 472         return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
 473                 (entry->offset >> L1_CACHE_SHIFT);
 474 }
 475
 476 static int active_cacheline_read_overlap(phys_addr_t cln)
 477 {
 478         int overlap = 0, i;
 479
 480         for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
 481                 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
 482                         overlap |= 1 << i;
 483         return overlap;
 484 }
 485
 486 static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
 487 {
 488         int i;
 489
 490         if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
 491                 return overlap;
 492
 493         for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
 494                 if (overlap & 1 << i)
 495                         radix_tree_tag_set(&dma_active_cacheline, cln, i);
 496                 else
 497                         radix_tree_tag_clear(&dma_active_cacheline, cln, i);
 498
 499         return overlap;
 500 }
 501
 502 static void active_cacheline_inc_overlap(phys_addr_t cln)
 503 {
 504         int overlap = active_cacheline_read_overlap(cln);
 505
 506         overlap = active_cacheline_set_overlap(cln, ++overlap);
 507
 508         /* If we overflowed the overlap counter then we're potentially
 509          * leaking dma-mappings.  Otherwise, if maps and unmaps are
 510          * balanced then this overflow may cause false negatives in
 511          * debug_dma_assert_idle() as the cacheline may be marked idle
 512          * prematurely.
 513          */
 514         WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
 515                   "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
 516                   ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
 517 }
 518
 519 static int active_cacheline_dec_overlap(phys_addr_t cln)
 520 {
 521         int overlap = active_cacheline_read_overlap(cln);
 522
 523         return active_cacheline_set_overlap(cln, --overlap);
 524 }
 525
 526 static int active_cacheline_insert(struct dma_debug_entry *entry)
 527 {
 528         phys_addr_t cln = to_cacheline_number(entry);
 529         unsigned long flags;
 530         int rc;
 531
 532         /* If the device is not writing memory then we don't have any
 533          * concerns about the cpu consuming stale data.  This mitigates
 534          * legitimate usages of overlapping mappings.
 535          */
 536         if (entry->direction == DMA_TO_DEVICE)
 537                 return 0;
 538
 539         spin_lock_irqsave(&radix_lock, flags);
 540         rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
 541         if (rc == -EEXIST)
 542                 active_cacheline_inc_overlap(cln);
 543         spin_unlock_irqrestore(&radix_lock, flags);
 544
 545         return rc;
 546 }
 547
 548 static void active_cacheline_remove(struct dma_debug_entry *entry)
 549 {
 550         phys_addr_t cln = to_cacheline_number(entry);
 551         unsigned long flags;
 552
 553         /* ...mirror the insert case */
 554         if (entry->direction == DMA_TO_DEVICE)
 555                 return;
 556
 557         spin_lock_irqsave(&radix_lock, flags);
 558         /* since we are counting overlaps the final put of the
 559          * cacheline will occur when the overlap count is 0.
 560          * active_cacheline_dec_overlap() returns -1 in that case
 561          */
 562         if (active_cacheline_dec_overlap(cln) < 0)
 563                 radix_tree_delete(&dma_active_cacheline, cln);
 564         spin_unlock_irqrestore(&radix_lock, flags);
 565 }
 566
 567 /**
 568  * debug_dma_assert_idle() - assert that a page is not undergoing dma
 569  * @page: page to lookup in the dma_active_cacheline tree
 570  *
 571  * Place a call to this routine in cases where the cpu touching the page
 572  * before the dma completes (page is dma_unmapped) will lead to data
 573  * corruption.
 574  */
 575 void debug_dma_assert_idle(struct page *page)
 576 {
 577         static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
 578         struct dma_debug_entry *entry = NULL;
 579         void **results = (void **) &ents;
 580         unsigned int nents, i;
 581         unsigned long flags;
 582         phys_addr_t cln;
 583
 584         if (dma_debug_disabled())
 585                 return;
 586
 587         if (!page)
 588                 return;
 589
 590         cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
 591         spin_lock_irqsave(&radix_lock, flags);
 592         nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
 593                                        CACHELINES_PER_PAGE);
 594         for (i = 0; i < nents; i++) {
 595                 phys_addr_t ent_cln = to_cacheline_number(ents[i]);
 596
 597                 if (ent_cln == cln) {
 598                         entry = ents[i];
 599                         break;
 600                 } else if (ent_cln >= cln + CACHELINES_PER_PAGE)
 601                         break;
 602         }
 603         spin_unlock_irqrestore(&radix_lock, flags);
 604
 605         if (!entry)
 606                 return;
 607
 608         cln = to_cacheline_number(entry);
 609         err_printk(entry->dev, entry,
 610                    "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
 611                    &cln);
 612 }
 613
 614 /*
 615  * Wrapper function for adding an entry to the hash.
 616  * This function takes care of locking itself.
 617  */
 618 static void add_dma_entry(struct dma_debug_entry *entry)
 619 {
 620         struct hash_bucket *bucket;
 621         unsigned long flags;
 622         int rc;
 623
 624         bucket = get_hash_bucket(entry, &flags);
 625         hash_bucket_add(bucket, entry);
 626         put_hash_bucket(bucket, &flags);
 627
 628         rc = active_cacheline_insert(entry);
 629         if (rc == -ENOMEM) {
 630                 pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
 631                 global_disable = true;
 632         }
 633
 634         /* TODO: report -EEXIST errors here as overlapping mappings are
 635          * not supported by the DMA API
 636          */
 637 }
 638
 639 static struct dma_debug_entry *__dma_entry_alloc(void)
 640 {
 641         struct dma_debug_entry *entry;
 642
 643         entry = list_entry(free_entries.next, struct dma_debug_entry, list);
 644         list_del(&entry->list);
 645         memset(entry, 0, sizeof(*entry));
 646
 647         num_free_entries -= 1;
 648         if (num_free_entries < min_free_entries)
 649                 min_free_entries = num_free_entries;
 650
 651         return entry;
 652 }
 653
 654 /* struct dma_entry allocator
 655  *
 656  * The next two functions implement the allocator for
 657  * struct dma_debug_entries.
 658  */
 659 static struct dma_debug_entry *dma_entry_alloc(void)
 660 {
 661         struct dma_debug_entry *entry;
 662         unsigned long flags;
 663
 664         spin_lock_irqsave(&free_entries_lock, flags);
 665
 666         if (list_empty(&free_entries)) {
 667                 global_disable = true;
 668                 spin_unlock_irqrestore(&free_entries_lock, flags);
 669                 pr_err("DMA-API: debugging out of memory - disabling\n");
 670                 return NULL;
 671         }
 672
 673         entry = __dma_entry_alloc();
 674
 675         spin_unlock_irqrestore(&free_entries_lock, flags);
 676
 677 #ifdef CONFIG_STACKTRACE
 678         entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
 679         entry->stacktrace.entries = entry->st_entries;
 680         entry->stacktrace.skip = 2;
 681         save_stack_trace(&entry->stacktrace);
 682 #endif
 683
 684         return entry;
 685 }
 686
 687 static void dma_entry_free(struct dma_debug_entry *entry)
 688 {
 689         unsigned long flags;
 690
 691         active_cacheline_remove(entry);
 692
 693         /*
 694          * add to beginning of the list - this way the entries are
 695          * more likely cache hot when they are reallocated.
 696          */
 697         spin_lock_irqsave(&free_entries_lock, flags);
 698         list_add(&entry->list, &free_entries);
 699         num_free_entries += 1;
 700         spin_unlock_irqrestore(&free_entries_lock, flags);
 701 }
 702
 703 int dma_debug_resize_entries(u32 num_entries)
 704 {
 705         int i, delta, ret = 0;
 706         unsigned long flags;
 707         struct dma_debug_entry *entry;
 708         LIST_HEAD(tmp);
 709
 710         spin_lock_irqsave(&free_entries_lock, flags);
 711
 712         if (nr_total_entries < num_entries) {
 713                 delta = num_entries - nr_total_entries;
 714
 715                 spin_unlock_irqrestore(&free_entries_lock, flags);
 716
 717                 for (i = 0; i < delta; i++) {
 718                         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 719                         if (!entry)
 720                                 break;
 721
 722                         list_add_tail(&entry->list, &tmp);
 723                 }
 724
 725                 spin_lock_irqsave(&free_entries_lock, flags);
 726
 727                 list_splice(&tmp, &free_entries);
 728                 nr_total_entries += i;
 729                 num_free_entries += i;
 730         } else {
 731                 delta = nr_total_entries - num_entries;
 732
 733                 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
 734                         entry = __dma_entry_alloc();
 735                         kfree(entry);
 736                 }
 737
 738                 nr_total_entries -= i;
 739         }
 740
 741         if (nr_total_entries != num_entries)
 742                 ret = 1;
 743
 744         spin_unlock_irqrestore(&free_entries_lock, flags);
 745
 746         return ret;
 747 }
 748 EXPORT_SYMBOL(dma_debug_resize_entries);
 749
 750 /*
 751  * DMA-API debugging init code
 752  *
 753  * The init code does two things:
 754  *   1. Initialize core data structures
 755  *   2. Preallocate a given number of dma_debug_entry structs
 756  */
 757
 758 static int prealloc_memory(u32 num_entries)
 759 {
 760         struct dma_debug_entry *entry, *next_entry;
 761         int i;
 762
 763         for (i = 0; i < num_entries; ++i) {
 764                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 765                 if (!entry)
 766                         goto out_err;
 767
 768                 list_add_tail(&entry->list, &free_entries);
 769         }
 770
 771         num_free_entries = num_entries;
 772         min_free_entries = num_entries;
 773
 774         pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
 775
 776         return 0;
 777
 778 out_err:
 779
 780         list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
 781                 list_del(&entry->list);
 782                 kfree(entry);
 783         }
 784
 785         return -ENOMEM;
 786 }
 787
 788 static ssize_t filter_read(struct file *file, char __user *user_buf,
 789                            size_t count, loff_t *ppos)
 790 {
 791         char buf[NAME_MAX_LEN + 1];
 792         unsigned long flags;
 793         int len;
 794
 795         if (!current_driver_name[0])
 796                 return 0;
 797
 798         /*
 799          * We can't copy to userspace directly because current_driver_name can
 800          * only be read under the driver_name_lock with irqs disabled. So
 801          * create a temporary copy first.
 802          */
 803         read_lock_irqsave(&driver_name_lock, flags);
 804         len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
 805         read_unlock_irqrestore(&driver_name_lock, flags);
 806
 807         return simple_read_from_buffer(user_buf, count, ppos, buf, len);
 808 }
 809
 810 static ssize_t filter_write(struct file *file, const char __user *userbuf,
 811                             size_t count, loff_t *ppos)
 812 {
 813         char buf[NAME_MAX_LEN];
 814         unsigned long flags;
 815         size_t len;
 816         int i;
 817
 818         /*
 819          * We can't copy from userspace directly. Access to
 820          * current_driver_name is protected with a write_lock with irqs
 821          * disabled. Since copy_from_user can fault and may sleep we
 822          * need to copy to temporary buffer first
 823          */
 824         len = min(count, (size_t)(NAME_MAX_LEN - 1));
 825         if (copy_from_user(buf, userbuf, len))
 826                 return -EFAULT;
 827
 828         buf[len] = 0;
 829
 830         write_lock_irqsave(&driver_name_lock, flags);
 831
 832         /*
 833          * Now handle the string we got from userspace very carefully.
 834          * The rules are:
 835          *         - only use the first token we got
 836          *         - token delimiter is everything looking like a space
 837          *           character (' ', '\n', '\t' ...)
 838          *
 839          */
 840         if (!isalnum(buf[0])) {
 841                 /*
 842                  * If the first character userspace gave us is not
 843                  * alphanumerical then assume the filter should be
 844                  * switched off.
 845                  */
 846                 if (current_driver_name[0])
 847                         pr_info("DMA-API: switching off dma-debug driver filter\n");
 848                 current_driver_name[0] = 0;
 849                 current_driver = NULL;
 850                 goto out_unlock;
 851         }
 852
 853         /*
 854          * Now parse out the first token and use it as the name for the
 855          * driver to filter for.
 856          */
 857         for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
 858                 current_driver_name[i] = buf[i];
 859                 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
 860                         break;
 861         }
 862         current_driver_name[i] = 0;
 863         current_driver = NULL;
 864
 865         pr_info("DMA-API: enable driver filter for driver [%s]\n",
 866                 current_driver_name);
 867
 868 out_unlock:
 869         write_unlock_irqrestore(&driver_name_lock, flags);
 870
 871         return count;
 872 }
 873
 874 static const struct file_operations filter_fops = {
 875         .read  = filter_read,
 876         .write = filter_write,
 877         .llseek = default_llseek,
 878 };
 879
 880 static int dma_debug_fs_init(void)
 881 {
 882         dma_debug_dent = debugfs_create_dir("dma-api", NULL);
 883         if (!dma_debug_dent) {
 884                 pr_err("DMA-API: can not create debugfs directory\n");
 885                 return -ENOMEM;
 886         }
 887
 888         global_disable_dent = debugfs_create_bool("disabled", 0444,
 889                         dma_debug_dent,
 890                         &global_disable);
 891         if (!global_disable_dent)
 892                 goto out_err;
 893
 894         error_count_dent = debugfs_create_u32("error_count", 0444,
 895                         dma_debug_dent, &error_count);
 896         if (!error_count_dent)
 897                 goto out_err;
 898
 899         show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
 900                         dma_debug_dent,
 901                         &show_all_errors);
 902         if (!show_all_errors_dent)
 903                 goto out_err;
 904
 905         show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
 906                         dma_debug_dent,
 907                         &show_num_errors);
 908         if (!show_num_errors_dent)
 909                 goto out_err;
 910
 911         num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
 912                         dma_debug_dent,
 913                         &num_free_entries);
 914         if (!num_free_entries_dent)
 915                 goto out_err;
 916
 917         min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
 918                         dma_debug_dent,
 919                         &min_free_entries);
 920         if (!min_free_entries_dent)
 921                 goto out_err;
 922
 923         filter_dent = debugfs_create_file("driver_filter", 0644,
 924                                           dma_debug_dent, NULL, &filter_fops);
 925         if (!filter_dent)
 926                 goto out_err;
 927
 928         return 0;
 929
 930 out_err:
 931         debugfs_remove_recursive(dma_debug_dent);
 932
 933         return -ENOMEM;
 934 }
 935
 936 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
 937 {
 938         struct dma_debug_entry *entry;
 939         unsigned long flags;
 940         int count = 0, i;
 941
 942         local_irq_save(flags);
 943
 944         for (i = 0; i < HASH_SIZE; ++i) {
 945                 spin_lock(&dma_entry_hash[i].lock);
 946                 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
 947                         if (entry->dev == dev) {
 948                                 count += 1;
 949                                 *out_entry = entry;
 950                         }
 951                 }
 952                 spin_unlock(&dma_entry_hash[i].lock);
 953         }
 954
 955         local_irq_restore(flags);
 956
 957         return count;
 958 }
 959
 960 static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
 961 {
 962         struct device *dev = data;
 963         struct dma_debug_entry *uninitialized_var(entry);
 964         int count;
 965
 966         if (dma_debug_disabled())
 967                 return 0;
 968
 969         switch (action) {
 970         case BUS_NOTIFY_UNBOUND_DRIVER:
 971                 count = device_dma_allocations(dev, &entry);
 972                 if (count == 0)
 973                         break;
 974                 err_printk(dev, entry, "DMA-API: device driver has pending "
 975                                 "DMA allocations while released from device "
 976                                 "[count=%d]\n"
 977                                 "One of leaked entries details: "
 978                                 "[device address=0x%016llx] [size=%llu bytes] "
 979                                 "[mapped with %s] [mapped as %s]\n",
 980                         count, entry->dev_addr, entry->size,
 981                         dir2name[entry->direction], type2name[entry->type]);
 982                 break;
 983         default:
 984                 break;
 985         }
 986
 987         return 0;
 988 }
 989
 990 void dma_debug_add_bus(struct bus_type *bus)
 991 {
 992         struct notifier_block *nb;
 993
 994         if (dma_debug_disabled())
 995                 return;
 996
 997         nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
 998         if (nb == NULL) {
 999                 pr_err("dma_debug_add_bus: out of memory\n");
1000                 return;
1001         }
1002
1003         nb->notifier_call = dma_debug_device_change;
1004
1005         bus_register_notifier(bus, nb);
1006 }
1007
1008 /*
1009  * Let the architectures decide how many entries should be preallocated.
1010  */
1011 void dma_debug_init(u32 num_entries)
1012 {
1013         int i;
1014
1015         /* Do not use dma_debug_initialized here, since we really want to be
1016          * called to set dma_debug_initialized
1017          */
1018         if (global_disable)
1019                 return;
1020
1021         for (i = 0; i < HASH_SIZE; ++i) {
1022                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
1023                 spin_lock_init(&dma_entry_hash[i].lock);
1024         }
1025
1026         if (dma_debug_fs_init() != 0) {
1027                 pr_err("DMA-API: error creating debugfs entries - disabling\n");
1028                 global_disable = true;
1029
1030                 return;
1031         }
1032
1033         if (req_entries)
1034                 num_entries = req_entries;
1035
1036         if (prealloc_memory(num_entries) != 0) {
1037                 pr_err("DMA-API: debugging out of memory error - disabled\n");
1038                 global_disable = true;
1039
1040                 return;
1041         }
1042
1043         nr_total_entries = num_free_entries;
1044
1045         dma_debug_initialized = true;
1046
1047         pr_info("DMA-API: debugging enabled by kernel config\n");
1048 }
1049
1050 static __init int dma_debug_cmdline(char *str)
1051 {
1052         if (!str)
1053                 return -EINVAL;
1054
1055         if (strncmp(str, "off", 3) == 0) {
1056                 pr_info("DMA-API: debugging disabled on kernel command line\n");
1057                 global_disable = true;
1058         }
1059
1060         return 0;
1061 }
1062
1063 static __init int dma_debug_entries_cmdline(char *str)
1064 {
1065         int res;
1066
1067         if (!str)
1068                 return -EINVAL;
1069
1070         res = get_option(&str, &req_entries);
1071
1072         if (!res)
1073                 req_entries = 0;
1074
1075         return 0;
1076 }
1077
1078 __setup("dma_debug=", dma_debug_cmdline);
1079 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
1080
1081 static void check_unmap(struct dma_debug_entry *ref)
1082 {
1083         struct dma_debug_entry *entry;
1084         struct hash_bucket *bucket;
1085         unsigned long flags;
1086
1087         bucket = get_hash_bucket(ref, &flags);
1088         entry = bucket_find_exact(bucket, ref);
1089
1090         if (!entry) {
1091                 /* must drop lock before calling dma_mapping_error */
1092                 put_hash_bucket(bucket, &flags);
1093
1094                 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
1095                         err_printk(ref->dev, NULL,
1096                                    "DMA-API: device driver tries to free an "
1097                                    "invalid DMA memory address\n");
1098                 } else {
1099                         err_printk(ref->dev, NULL,
1100                                    "DMA-API: device driver tries to free DMA "
1101                                    "memory it has not allocated [device "
1102                                    "address=0x%016llx] [size=%llu bytes]\n",
1103                                    ref->dev_addr, ref->size);
1104                 }
1105                 return;
1106         }
1107
1108         if (ref->size != entry->size) {
1109                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1110                            "DMA memory with different size "
1111                            "[device address=0x%016llx] [map size=%llu bytes] "
1112                            "[unmap size=%llu bytes]\n",
1113                            ref->dev_addr, entry->size, ref->size);
1114         }
1115
1116         if (ref->type != entry->type) {
1117                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1118                            "DMA memory with wrong function "
1119                            "[device address=0x%016llx] [size=%llu bytes] "
1120                            "[mapped as %s] [unmapped as %s]\n",
1121                            ref->dev_addr, ref->size,
1122                            type2name[entry->type], type2name[ref->type]);
1123         } else if ((entry->type == dma_debug_coherent) &&
1124                    (phys_addr(ref) != phys_addr(entry))) {
1125                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1126                            "DMA memory with different CPU address "
1127                            "[device address=0x%016llx] [size=%llu bytes] "
1128                            "[cpu alloc address=0x%016llx] "
1129                            "[cpu free address=0x%016llx]",
1130                            ref->dev_addr, ref->size,
1131                            phys_addr(entry),
1132                            phys_addr(ref));
1133         }
1134
1135         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1136             ref->sg_call_ents != entry->sg_call_ents) {
1137                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1138                            "DMA sg list with different entry count "
1139                            "[map count=%d] [unmap count=%d]\n",
1140                            entry->sg_call_ents, ref->sg_call_ents);
1141         }
1142
1143         /*
1144          * This may be no bug in reality - but most implementations of the
1145          * DMA API don't handle this properly, so check for it here
1146          */
1147         if (ref->direction != entry->direction) {
1148                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1149                            "DMA memory with different direction "
1150                            "[device address=0x%016llx] [size=%llu bytes] "
1151                            "[mapped with %s] [unmapped with %s]\n",
1152                            ref->dev_addr, ref->size,
1153                            dir2name[entry->direction],
1154                            dir2name[ref->direction]);
1155         }
1156
1157         if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1158                 err_printk(ref->dev, entry,
1159                            "DMA-API: device driver failed to check map error"
1160                            "[device address=0x%016llx] [size=%llu bytes] "
1161                            "[mapped as %s]",
1162                            ref->dev_addr, ref->size,
1163                            type2name[entry->type]);
1164         }
1165
1166         hash_bucket_del(entry);
1167         dma_entry_free(entry);
1168
1169         put_hash_bucket(bucket, &flags);
1170 }
1171
1172 static void check_for_stack(struct device *dev, void *addr)
1173 {
1174         if (object_is_on_stack(addr))
1175                 err_printk(dev, NULL, "DMA-API: device driver maps memory from "
1176                                 "stack [addr=%p]\n", addr);
1177 }
1178
1179 static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
1180 {
1181         unsigned long a1 = (unsigned long)addr;
1182         unsigned long b1 = a1 + len;
1183         unsigned long a2 = (unsigned long)start;
1184         unsigned long b2 = (unsigned long)end;
1185
1186         return !(b1 <= a2 || a1 >= b2);
1187 }
1188
1189 static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1190 {
1191         if (overlap(addr, len, _stext, _etext) ||
1192             overlap(addr, len, __start_rodata, __end_rodata))
1193                 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1194 }
1195
1196 static void check_sync(struct device *dev,
1197                        struct dma_debug_entry *ref,
1198                        bool to_cpu)
1199 {
1200         struct dma_debug_entry *entry;
1201         struct hash_bucket *bucket;
1202         unsigned long flags;
1203
1204         bucket = get_hash_bucket(ref, &flags);
1205
1206         entry = bucket_find_contain(&bucket, ref, &flags);
1207
1208         if (!entry) {
1209                 err_printk(dev, NULL, "DMA-API: device driver tries "
1210                                 "to sync DMA memory it has not allocated "
1211                                 "[device address=0x%016llx] [size=%llu bytes]\n",
1212                                 (unsigned long long)ref->dev_addr, ref->size);
1213                 goto out;
1214         }
1215
1216         if (ref->size > entry->size) {
1217                 err_printk(dev, entry, "DMA-API: device driver syncs"
1218                                 " DMA memory outside allocated range "
1219                                 "[device address=0x%016llx] "
1220                                 "[allocation size=%llu bytes] "
1221                                 "[sync offset+size=%llu]\n",
1222                                 entry->dev_addr, entry->size,
1223                                 ref->size);
1224         }
1225
1226         if (entry->direction == DMA_BIDIRECTIONAL)
1227                 goto out;
1228
1229         if (ref->direction != entry->direction) {
1230                 err_printk(dev, entry, "DMA-API: device driver syncs "
1231                                 "DMA memory with different direction "
1232                                 "[device address=0x%016llx] [size=%llu bytes] "
1233                                 "[mapped with %s] [synced with %s]\n",
1234                                 (unsigned long long)ref->dev_addr, entry->size,
1235                                 dir2name[entry->direction],
1236                                 dir2name[ref->direction]);
1237         }
1238
1239         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1240                       !(ref->direction == DMA_TO_DEVICE))
1241                 err_printk(dev, entry, "DMA-API: device driver syncs "
1242                                 "device read-only DMA memory for cpu "
1243                                 "[device address=0x%016llx] [size=%llu bytes] "
1244                                 "[mapped with %s] [synced with %s]\n",
1245                                 (unsigned long long)ref->dev_addr, entry->size,
1246                                 dir2name[entry->direction],
1247                                 dir2name[ref->direction]);
1248
1249         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1250                        !(ref->direction == DMA_FROM_DEVICE))
1251                 err_printk(dev, entry, "DMA-API: device driver syncs "
1252                                 "device write-only DMA memory to device "
1253                                 "[device address=0x%016llx] [size=%llu bytes] "
1254                                 "[mapped with %s] [synced with %s]\n",
1255                                 (unsigned long long)ref->dev_addr, entry->size,
1256                                 dir2name[entry->direction],
1257                                 dir2name[ref->direction]);
1258
1259         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1260             ref->sg_call_ents != entry->sg_call_ents) {
1261                 err_printk(ref->dev, entry, "DMA-API: device driver syncs "
1262                            "DMA sg list with different entry count "
1263                            "[map count=%d] [sync count=%d]\n",
1264                            entry->sg_call_ents, ref->sg_call_ents);
1265         }
1266
1267 out:
1268         put_hash_bucket(bucket, &flags);
1269 }
1270
1271 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1272                         size_t size, int direction, dma_addr_t dma_addr,
1273                         bool map_single)
1274 {
1275         struct dma_debug_entry *entry;
1276
1277         if (unlikely(dma_debug_disabled()))
1278                 return;
1279
1280         if (dma_mapping_error(dev, dma_addr))
1281                 return;
1282
1283         entry = dma_entry_alloc();
1284         if (!entry)
1285                 return;
1286
1287         entry->dev       = dev;
1288         entry->type      = dma_debug_page;
1289         entry->pfn       = page_to_pfn(page);
1290         entry->offset    = offset,
1291         entry->dev_addr  = dma_addr;
1292         entry->size      = size;
1293         entry->direction = direction;
1294         entry->map_err_type = MAP_ERR_NOT_CHECKED;
1295
1296         if (map_single)
1297                 entry->type = dma_debug_single;
1298
1299         if (!PageHighMem(page)) {
1300                 void *addr = page_address(page) + offset;
1301
1302                 check_for_stack(dev, addr);
1303                 check_for_illegal_area(dev, addr, size);
1304         }
1305
1306         add_dma_entry(entry);
1307 }
1308 EXPORT_SYMBOL(debug_dma_map_page);
1309
1310 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1311 {
1312         struct dma_debug_entry ref;
1313         struct dma_debug_entry *entry;
1314         struct hash_bucket *bucket;
1315         unsigned long flags;
1316
1317         if (unlikely(dma_debug_disabled()))
1318                 return;
1319
1320         ref.dev = dev;
1321         ref.dev_addr = dma_addr;
1322         bucket = get_hash_bucket(&ref, &flags);
1323
1324         list_for_each_entry(entry, &bucket->list, list) {
1325                 if (!exact_match(&ref, entry))
1326                         continue;
1327
1328                 /*
1329                  * The same physical address can be mapped multiple
1330                  * times. Without a hardware IOMMU this results in the
1331                  * same device addresses being put into the dma-debug
1332                  * hash multiple times too. This can result in false
1333                  * positives being reported. Therefore we implement a
1334                  * best-fit algorithm here which updates the first entry
1335                  * from the hash which fits the reference value and is
1336                  * not currently listed as being checked.
1337                  */
1338                 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1339                         entry->map_err_type = MAP_ERR_CHECKED;
1340                         break;
1341                 }
1342         }
1343
1344         put_hash_bucket(bucket, &flags);
1345 }
1346 EXPORT_SYMBOL(debug_dma_mapping_error);
1347
1348 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1349                           size_t size, int direction, bool map_single)
1350 {
1351         struct dma_debug_entry ref = {
1352                 .type           = dma_debug_page,
1353                 .dev            = dev,
1354                 .dev_addr       = addr,
1355                 .size           = size,
1356                 .direction      = direction,
1357         };
1358
1359         if (unlikely(dma_debug_disabled()))
1360                 return;
1361
1362         if (map_single)
1363                 ref.type = dma_debug_single;
1364
1365         check_unmap(&ref);
1366 }
1367 EXPORT_SYMBOL(debug_dma_unmap_page);
1368
1369 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1370                       int nents, int mapped_ents, int direction)
1371 {
1372         struct dma_debug_entry *entry;
1373         struct scatterlist *s;
1374         int i;
1375
1376         if (unlikely(dma_debug_disabled()))
1377                 return;
1378
1379         for_each_sg(sg, s, mapped_ents, i) {
1380                 entry = dma_entry_alloc();
1381                 if (!entry)
1382                         return;
1383
1384                 entry->type           = dma_debug_sg;
1385                 entry->dev            = dev;
1386                 entry->pfn            = page_to_pfn(sg_page(s));
1387                 entry->offset         = s->offset,
1388                 entry->size           = sg_dma_len(s);
1389                 entry->dev_addr       = sg_dma_address(s);
1390                 entry->direction      = direction;
1391                 entry->sg_call_ents   = nents;
1392                 entry->sg_mapped_ents = mapped_ents;
1393
1394                 if (!PageHighMem(sg_page(s))) {
1395                         check_for_stack(dev, sg_virt(s));
1396                         check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1397                 }
1398
1399                 add_dma_entry(entry);
1400         }
1401 }
1402 EXPORT_SYMBOL(debug_dma_map_sg);
1403
1404 static int get_nr_mapped_entries(struct device *dev,
1405                                  struct dma_debug_entry *ref)
1406 {
1407         struct dma_debug_entry *entry;
1408         struct hash_bucket *bucket;
1409         unsigned long flags;
1410         int mapped_ents;
1411
1412         bucket       = get_hash_bucket(ref, &flags);
1413         entry        = bucket_find_exact(bucket, ref);
1414         mapped_ents  = 0;
1415
1416         if (entry)
1417                 mapped_ents = entry->sg_mapped_ents;
1418         put_hash_bucket(bucket, &flags);
1419
1420         return mapped_ents;
1421 }
1422
1423 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1424                         int nelems, int dir)
1425 {
1426         struct scatterlist *s;
1427         int mapped_ents = 0, i;
1428
1429         if (unlikely(dma_debug_disabled()))
1430                 return;
1431
1432         for_each_sg(sglist, s, nelems, i) {
1433
1434                 struct dma_debug_entry ref = {
1435                         .type           = dma_debug_sg,
1436                         .dev            = dev,
1437                         .pfn            = page_to_pfn(sg_page(s)),
1438                         .offset         = s->offset,
1439                         .dev_addr       = sg_dma_address(s),
1440                         .size           = sg_dma_len(s),
1441                         .direction      = dir,
1442                         .sg_call_ents   = nelems,
1443                 };
1444
1445                 if (mapped_ents && i >= mapped_ents)
1446                         break;
1447
1448                 if (!i)
1449                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1450
1451                 check_unmap(&ref);
1452         }
1453 }
1454 EXPORT_SYMBOL(debug_dma_unmap_sg);
1455
1456 void debug_dma_alloc_coherent(struct device *dev, size_t size,
1457                               dma_addr_t dma_addr, void *virt)
1458 {
1459         struct dma_debug_entry *entry;
1460
1461         if (unlikely(dma_debug_disabled()))
1462                 return;
1463
1464         if (unlikely(virt == NULL))
1465                 return;
1466
1467         entry = dma_entry_alloc();
1468         if (!entry)
1469                 return;
1470
1471         entry->type      = dma_debug_coherent;
1472         entry->dev       = dev;
1473         entry->pfn       = page_to_pfn(virt_to_page(virt));
1474         entry->offset    = (size_t) virt & ~PAGE_MASK;
1475         entry->size      = size;
1476         entry->dev_addr  = dma_addr;
1477         entry->direction = DMA_BIDIRECTIONAL;
1478
1479         add_dma_entry(entry);
1480 }
1481 EXPORT_SYMBOL(debug_dma_alloc_coherent);
1482
1483 void debug_dma_free_coherent(struct device *dev, size_t size,
1484                          void *virt, dma_addr_t addr)
1485 {
1486         struct dma_debug_entry ref = {
1487                 .type           = dma_debug_coherent,
1488                 .dev            = dev,
1489                 .pfn            = page_to_pfn(virt_to_page(virt)),
1490                 .offset         = (size_t) virt & ~PAGE_MASK,
1491                 .dev_addr       = addr,
1492                 .size           = size,
1493                 .direction      = DMA_BIDIRECTIONAL,
1494         };
1495
1496         if (unlikely(dma_debug_disabled()))
1497                 return;
1498
1499         check_unmap(&ref);
1500 }
1501 EXPORT_SYMBOL(debug_dma_free_coherent);
1502
1503 void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
1504                             int direction, dma_addr_t dma_addr)
1505 {
1506         struct dma_debug_entry *entry;
1507
1508         if (unlikely(dma_debug_disabled()))
1509                 return;
1510
1511         entry = dma_entry_alloc();
1512         if (!entry)
1513                 return;
1514
1515         entry->type             = dma_debug_resource;
1516         entry->dev              = dev;
1517         entry->pfn              = PHYS_PFN(addr);
1518         entry->offset           = offset_in_page(addr);
1519         entry->size             = size;
1520         entry->dev_addr         = dma_addr;
1521         entry->direction        = direction;
1522         entry->map_err_type     = MAP_ERR_NOT_CHECKED;
1523
1524         add_dma_entry(entry);
1525 }
1526 EXPORT_SYMBOL(debug_dma_map_resource);
1527
1528 void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
1529                               size_t size, int direction)
1530 {
1531         struct dma_debug_entry ref = {
1532                 .type           = dma_debug_resource,
1533                 .dev            = dev,
1534                 .dev_addr       = dma_addr,
1535                 .size           = size,
1536                 .direction      = direction,
1537         };
1538
1539         if (unlikely(dma_debug_disabled()))
1540                 return;
1541
1542         check_unmap(&ref);
1543 }
1544 EXPORT_SYMBOL(debug_dma_unmap_resource);
1545
1546 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1547                                    size_t size, int direction)
1548 {
1549         struct dma_debug_entry ref;
1550
1551         if (unlikely(dma_debug_disabled()))
1552                 return;
1553
1554         ref.type         = dma_debug_single;
1555         ref.dev          = dev;
1556         ref.dev_addr     = dma_handle;
1557         ref.size         = size;
1558         ref.direction    = direction;
1559         ref.sg_call_ents = 0;
1560
1561         check_sync(dev, &ref, true);
1562 }
1563 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1564
1565 void debug_dma_sync_single_for_device(struct device *dev,
1566                                       dma_addr_t dma_handle, size_t size,
1567                                       int direction)
1568 {
1569         struct dma_debug_entry ref;
1570
1571         if (unlikely(dma_debug_disabled()))
1572                 return;
1573
1574         ref.type         = dma_debug_single;
1575         ref.dev          = dev;
1576         ref.dev_addr     = dma_handle;
1577         ref.size         = size;
1578         ref.direction    = direction;
1579         ref.sg_call_ents = 0;
1580
1581         check_sync(dev, &ref, false);
1582 }
1583 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1584
1585 void debug_dma_sync_single_range_for_cpu(struct device *dev,
1586                                          dma_addr_t dma_handle,
1587                                          unsigned long offset, size_t size,
1588                                          int direction)
1589 {
1590         struct dma_debug_entry ref;
1591
1592         if (unlikely(dma_debug_disabled()))
1593                 return;
1594
1595         ref.type         = dma_debug_single;
1596         ref.dev          = dev;
1597         ref.dev_addr     = dma_handle;
1598         ref.size         = offset + size;
1599         ref.direction    = direction;
1600         ref.sg_call_ents = 0;
1601
1602         check_sync(dev, &ref, true);
1603 }
1604 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1605
1606 void debug_dma_sync_single_range_for_device(struct device *dev,
1607                                             dma_addr_t dma_handle,
1608                                             unsigned long offset,
1609                                             size_t size, int direction)
1610 {
1611         struct dma_debug_entry ref;
1612
1613         if (unlikely(dma_debug_disabled()))
1614                 return;
1615
1616         ref.type         = dma_debug_single;
1617         ref.dev          = dev;
1618         ref.dev_addr     = dma_handle;
1619         ref.size         = offset + size;
1620         ref.direction    = direction;
1621         ref.sg_call_ents = 0;
1622
1623         check_sync(dev, &ref, false);
1624 }
1625 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1626
1627 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1628                                int nelems, int direction)
1629 {
1630         struct scatterlist *s;
1631         int mapped_ents = 0, i;
1632
1633         if (unlikely(dma_debug_disabled()))
1634                 return;
1635
1636         for_each_sg(sg, s, nelems, i) {
1637
1638                 struct dma_debug_entry ref = {
1639                         .type           = dma_debug_sg,
1640                         .dev            = dev,
1641                         .pfn            = page_to_pfn(sg_page(s)),
1642                         .offset         = s->offset,
1643                         .dev_addr       = sg_dma_address(s),
1644                         .size           = sg_dma_len(s),
1645                         .direction      = direction,
1646                         .sg_call_ents   = nelems,
1647                 };
1648
1649                 if (!i)
1650                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1651
1652                 if (i >= mapped_ents)
1653                         break;
1654
1655                 check_sync(dev, &ref, true);
1656         }
1657 }
1658 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1659
1660 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1661                                   int nelems, int direction)
1662 {
1663         struct scatterlist *s;
1664         int mapped_ents = 0, i;
1665
1666         if (unlikely(dma_debug_disabled()))
1667                 return;
1668
1669         for_each_sg(sg, s, nelems, i) {
1670
1671                 struct dma_debug_entry ref = {
1672                         .type           = dma_debug_sg,
1673                         .dev            = dev,
1674                         .pfn            = page_to_pfn(sg_page(s)),
1675                         .offset         = s->offset,
1676                         .dev_addr       = sg_dma_address(s),
1677                         .size           = sg_dma_len(s),
1678                         .direction      = direction,
1679                         .sg_call_ents   = nelems,
1680                 };
1681                 if (!i)
1682                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1683
1684                 if (i >= mapped_ents)
1685                         break;
1686
1687                 check_sync(dev, &ref, false);
1688         }
1689 }
1690 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1691
1692 static int __init dma_debug_driver_setup(char *str)
1693 {
1694         int i;
1695
1696         for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1697                 current_driver_name[i] = *str;
1698                 if (*str == 0)
1699                         break;
1700         }
1701
1702         if (current_driver_name[0])
1703                 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1704                         current_driver_name);
1705
1706
1707         return 1;
1708 }
1709 __setup("dma_debug_driver=", dma_debug_driver_setup);