GNU Linux-libre 4.4.284-gnu1
[releases.git] / 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 };
47
48 enum map_err_types {
49         MAP_ERR_CHECK_NOT_APPLICABLE,
50         MAP_ERR_NOT_CHECKED,
51         MAP_ERR_CHECKED,
52 };
53
54 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
55
56 /**
57  * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
58  * @list: node on pre-allocated free_entries list
59  * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
60  * @type: single, page, sg, coherent
61  * @pfn: page frame of the start address
62  * @offset: offset of mapping relative to pfn
63  * @size: length of the mapping
64  * @direction: enum dma_data_direction
65  * @sg_call_ents: 'nents' from dma_map_sg
66  * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
67  * @map_err_type: track whether dma_mapping_error() was checked
68  * @stacktrace: support backtraces when a violation is detected
69  */
70 struct dma_debug_entry {
71         struct list_head list;
72         struct device    *dev;
73         int              type;
74         unsigned long    pfn;
75         size_t           offset;
76         u64              dev_addr;
77         u64              size;
78         int              direction;
79         int              sg_call_ents;
80         int              sg_mapped_ents;
81         enum map_err_types  map_err_type;
82 #ifdef CONFIG_STACKTRACE
83         struct           stack_trace stacktrace;
84         unsigned long    st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
85 #endif
86 };
87
88 typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
89
90 struct hash_bucket {
91         struct list_head list;
92         spinlock_t lock;
93 } ____cacheline_aligned_in_smp;
94
95 /* Hash list to save the allocated dma addresses */
96 static struct hash_bucket dma_entry_hash[HASH_SIZE];
97 /* List of pre-allocated dma_debug_entry's */
98 static LIST_HEAD(free_entries);
99 /* Lock for the list above */
100 static DEFINE_SPINLOCK(free_entries_lock);
101
102 /* Global disable flag - will be set in case of an error */
103 static bool global_disable __read_mostly;
104
105 /* Early initialization disable flag, set at the end of dma_debug_init */
106 static bool dma_debug_initialized __read_mostly;
107
108 static inline bool dma_debug_disabled(void)
109 {
110         return global_disable || !dma_debug_initialized;
111 }
112
113 /* Global error count */
114 static u32 error_count;
115
116 /* Global error show enable*/
117 static u32 show_all_errors __read_mostly;
118 /* Number of errors to show */
119 static u32 show_num_errors = 1;
120
121 static u32 num_free_entries;
122 static u32 min_free_entries;
123 static u32 nr_total_entries;
124
125 /* number of preallocated entries requested by kernel cmdline */
126 static u32 req_entries;
127
128 /* debugfs dentry's for the stuff above */
129 static struct dentry *dma_debug_dent        __read_mostly;
130 static struct dentry *global_disable_dent   __read_mostly;
131 static struct dentry *error_count_dent      __read_mostly;
132 static struct dentry *show_all_errors_dent  __read_mostly;
133 static struct dentry *show_num_errors_dent  __read_mostly;
134 static struct dentry *num_free_entries_dent __read_mostly;
135 static struct dentry *min_free_entries_dent __read_mostly;
136 static struct dentry *filter_dent           __read_mostly;
137
138 /* per-driver filter related state */
139
140 #define NAME_MAX_LEN    64
141
142 static char                  current_driver_name[NAME_MAX_LEN] __read_mostly;
143 static struct device_driver *current_driver                    __read_mostly;
144
145 static DEFINE_RWLOCK(driver_name_lock);
146
147 static const char *const maperr2str[] = {
148         [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
149         [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
150         [MAP_ERR_CHECKED] = "dma map error checked",
151 };
152
153 static const char *type2name[4] = { "single", "page",
154                                     "scather-gather", "coherent" };
155
156 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
157                                    "DMA_FROM_DEVICE", "DMA_NONE" };
158
159 /*
160  * The access to some variables in this macro is racy. We can't use atomic_t
161  * here because all these variables are exported to debugfs. Some of them even
162  * writeable. This is also the reason why a lock won't help much. But anyway,
163  * the races are no big deal. Here is why:
164  *
165  *   error_count: the addition is racy, but the worst thing that can happen is
166  *                that we don't count some errors
167  *   show_num_errors: the subtraction is racy. Also no big deal because in
168  *                    worst case this will result in one warning more in the
169  *                    system log than the user configured. This variable is
170  *                    writeable via debugfs.
171  */
172 static inline void dump_entry_trace(struct dma_debug_entry *entry)
173 {
174 #ifdef CONFIG_STACKTRACE
175         if (entry) {
176                 pr_warning("Mapped at:\n");
177                 print_stack_trace(&entry->stacktrace, 0);
178         }
179 #endif
180 }
181
182 static bool driver_filter(struct device *dev)
183 {
184         struct device_driver *drv;
185         unsigned long flags;
186         bool ret;
187
188         /* driver filter off */
189         if (likely(!current_driver_name[0]))
190                 return true;
191
192         /* driver filter on and initialized */
193         if (current_driver && dev && dev->driver == current_driver)
194                 return true;
195
196         /* driver filter on, but we can't filter on a NULL device... */
197         if (!dev)
198                 return false;
199
200         if (current_driver || !current_driver_name[0])
201                 return false;
202
203         /* driver filter on but not yet initialized */
204         drv = dev->driver;
205         if (!drv)
206                 return false;
207
208         /* lock to protect against change of current_driver_name */
209         read_lock_irqsave(&driver_name_lock, flags);
210
211         ret = false;
212         if (drv->name &&
213             strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
214                 current_driver = drv;
215                 ret = true;
216         }
217
218         read_unlock_irqrestore(&driver_name_lock, flags);
219
220         return ret;
221 }
222
223 #define err_printk(dev, entry, format, arg...) do {                     \
224                 error_count += 1;                                       \
225                 if (driver_filter(dev) &&                               \
226                     (show_all_errors || show_num_errors > 0)) {         \
227                         WARN(1, "%s %s: " format,                       \
228                              dev ? dev_driver_string(dev) : "NULL",     \
229                              dev ? dev_name(dev) : "NULL", ## arg);     \
230                         dump_entry_trace(entry);                        \
231                 }                                                       \
232                 if (!show_all_errors && show_num_errors > 0)            \
233                         show_num_errors -= 1;                           \
234         } while (0);
235
236 /*
237  * Hash related functions
238  *
239  * Every DMA-API request is saved into a struct dma_debug_entry. To
240  * have quick access to these structs they are stored into a hash.
241  */
242 static int hash_fn(struct dma_debug_entry *entry)
243 {
244         /*
245          * Hash function is based on the dma address.
246          * We use bits 20-27 here as the index into the hash
247          */
248         return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
249 }
250
251 /*
252  * Request exclusive access to a hash bucket for a given dma_debug_entry.
253  */
254 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
255                                            unsigned long *flags)
256 {
257         int idx = hash_fn(entry);
258         unsigned long __flags;
259
260         spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
261         *flags = __flags;
262         return &dma_entry_hash[idx];
263 }
264
265 /*
266  * Give up exclusive access to the hash bucket
267  */
268 static void put_hash_bucket(struct hash_bucket *bucket,
269                             unsigned long *flags)
270 {
271         unsigned long __flags = *flags;
272
273         spin_unlock_irqrestore(&bucket->lock, __flags);
274 }
275
276 static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
277 {
278         return ((a->dev_addr == b->dev_addr) &&
279                 (a->dev == b->dev)) ? true : false;
280 }
281
282 static bool containing_match(struct dma_debug_entry *a,
283                              struct dma_debug_entry *b)
284 {
285         if (a->dev != b->dev)
286                 return false;
287
288         if ((b->dev_addr <= a->dev_addr) &&
289             ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
290                 return true;
291
292         return false;
293 }
294
295 /*
296  * Search a given entry in the hash bucket list
297  */
298 static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
299                                                   struct dma_debug_entry *ref,
300                                                   match_fn match)
301 {
302         struct dma_debug_entry *entry, *ret = NULL;
303         int matches = 0, match_lvl, last_lvl = -1;
304
305         list_for_each_entry(entry, &bucket->list, list) {
306                 if (!match(ref, entry))
307                         continue;
308
309                 /*
310                  * Some drivers map the same physical address multiple
311                  * times. Without a hardware IOMMU this results in the
312                  * same device addresses being put into the dma-debug
313                  * hash multiple times too. This can result in false
314                  * positives being reported. Therefore we implement a
315                  * best-fit algorithm here which returns the entry from
316                  * the hash which fits best to the reference value
317                  * instead of the first-fit.
318                  */
319                 matches += 1;
320                 match_lvl = 0;
321                 entry->size         == ref->size         ? ++match_lvl : 0;
322                 entry->type         == ref->type         ? ++match_lvl : 0;
323                 entry->direction    == ref->direction    ? ++match_lvl : 0;
324                 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
325
326                 if (match_lvl == 4) {
327                         /* perfect-fit - return the result */
328                         return entry;
329                 } else if (match_lvl > last_lvl) {
330                         /*
331                          * We found an entry that fits better then the
332                          * previous one or it is the 1st match.
333                          */
334                         last_lvl = match_lvl;
335                         ret      = entry;
336                 }
337         }
338
339         /*
340          * If we have multiple matches but no perfect-fit, just return
341          * NULL.
342          */
343         ret = (matches == 1) ? ret : NULL;
344
345         return ret;
346 }
347
348 static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
349                                                  struct dma_debug_entry *ref)
350 {
351         return __hash_bucket_find(bucket, ref, exact_match);
352 }
353
354 static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
355                                                    struct dma_debug_entry *ref,
356                                                    unsigned long *flags)
357 {
358
359         unsigned int max_range = dma_get_max_seg_size(ref->dev);
360         struct dma_debug_entry *entry, index = *ref;
361         unsigned int range = 0;
362
363         while (range <= max_range) {
364                 entry = __hash_bucket_find(*bucket, ref, containing_match);
365
366                 if (entry)
367                         return entry;
368
369                 /*
370                  * Nothing found, go back a hash bucket
371                  */
372                 put_hash_bucket(*bucket, flags);
373                 range          += (1 << HASH_FN_SHIFT);
374                 index.dev_addr -= (1 << HASH_FN_SHIFT);
375                 *bucket = get_hash_bucket(&index, flags);
376         }
377
378         return NULL;
379 }
380
381 /*
382  * Add an entry to a hash bucket
383  */
384 static void hash_bucket_add(struct hash_bucket *bucket,
385                             struct dma_debug_entry *entry)
386 {
387         list_add_tail(&entry->list, &bucket->list);
388 }
389
390 /*
391  * Remove entry from a hash bucket list
392  */
393 static void hash_bucket_del(struct dma_debug_entry *entry)
394 {
395         list_del(&entry->list);
396 }
397
398 static unsigned long long phys_addr(struct dma_debug_entry *entry)
399 {
400         return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
401 }
402
403 /*
404  * Dump mapping entries for debugging purposes
405  */
406 void debug_dma_dump_mappings(struct device *dev)
407 {
408         int idx;
409
410         for (idx = 0; idx < HASH_SIZE; idx++) {
411                 struct hash_bucket *bucket = &dma_entry_hash[idx];
412                 struct dma_debug_entry *entry;
413                 unsigned long flags;
414
415                 spin_lock_irqsave(&bucket->lock, flags);
416
417                 list_for_each_entry(entry, &bucket->list, list) {
418                         if (!dev || dev == entry->dev) {
419                                 dev_info(entry->dev,
420                                          "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
421                                          type2name[entry->type], idx,
422                                          phys_addr(entry), entry->pfn,
423                                          entry->dev_addr, entry->size,
424                                          dir2name[entry->direction],
425                                          maperr2str[entry->map_err_type]);
426                         }
427                 }
428
429                 spin_unlock_irqrestore(&bucket->lock, flags);
430                 cond_resched();
431         }
432 }
433 EXPORT_SYMBOL(debug_dma_dump_mappings);
434
435 /*
436  * For each mapping (initial cacheline in the case of
437  * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
438  * scatterlist, or the cacheline specified in dma_map_single) insert
439  * into this tree using the cacheline as the key. At
440  * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry.  If
441  * the entry already exists at insertion time add a tag as a reference
442  * count for the overlapping mappings.  For now, the overlap tracking
443  * just ensures that 'unmaps' balance 'maps' before marking the
444  * cacheline idle, but we should also be flagging overlaps as an API
445  * violation.
446  *
447  * Memory usage is mostly constrained by the maximum number of available
448  * dma-debug entries in that we need a free dma_debug_entry before
449  * inserting into the tree.  In the case of dma_map_page and
450  * dma_alloc_coherent there is only one dma_debug_entry and one
451  * dma_active_cacheline entry to track per event.  dma_map_sg(), on the
452  * other hand, consumes a single dma_debug_entry, but inserts 'nents'
453  * entries into the tree.
454  *
455  * At any time debug_dma_assert_idle() can be called to trigger a
456  * warning if any cachelines in the given page are in the active set.
457  */
458 static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
459 static DEFINE_SPINLOCK(radix_lock);
460 #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
461 #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
462 #define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
463
464 static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
465 {
466         return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
467                 (entry->offset >> L1_CACHE_SHIFT);
468 }
469
470 static int active_cacheline_read_overlap(phys_addr_t cln)
471 {
472         int overlap = 0, i;
473
474         for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
475                 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
476                         overlap |= 1 << i;
477         return overlap;
478 }
479
480 static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
481 {
482         int i;
483
484         if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
485                 return overlap;
486
487         for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
488                 if (overlap & 1 << i)
489                         radix_tree_tag_set(&dma_active_cacheline, cln, i);
490                 else
491                         radix_tree_tag_clear(&dma_active_cacheline, cln, i);
492
493         return overlap;
494 }
495
496 static void active_cacheline_inc_overlap(phys_addr_t cln)
497 {
498         int overlap = active_cacheline_read_overlap(cln);
499
500         overlap = active_cacheline_set_overlap(cln, ++overlap);
501
502         /* If we overflowed the overlap counter then we're potentially
503          * leaking dma-mappings.  Otherwise, if maps and unmaps are
504          * balanced then this overflow may cause false negatives in
505          * debug_dma_assert_idle() as the cacheline may be marked idle
506          * prematurely.
507          */
508         WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
509                   "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
510                   ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
511 }
512
513 static int active_cacheline_dec_overlap(phys_addr_t cln)
514 {
515         int overlap = active_cacheline_read_overlap(cln);
516
517         return active_cacheline_set_overlap(cln, --overlap);
518 }
519
520 static int active_cacheline_insert(struct dma_debug_entry *entry)
521 {
522         phys_addr_t cln = to_cacheline_number(entry);
523         unsigned long flags;
524         int rc;
525
526         /* If the device is not writing memory then we don't have any
527          * concerns about the cpu consuming stale data.  This mitigates
528          * legitimate usages of overlapping mappings.
529          */
530         if (entry->direction == DMA_TO_DEVICE)
531                 return 0;
532
533         spin_lock_irqsave(&radix_lock, flags);
534         rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
535         if (rc == -EEXIST)
536                 active_cacheline_inc_overlap(cln);
537         spin_unlock_irqrestore(&radix_lock, flags);
538
539         return rc;
540 }
541
542 static void active_cacheline_remove(struct dma_debug_entry *entry)
543 {
544         phys_addr_t cln = to_cacheline_number(entry);
545         unsigned long flags;
546
547         /* ...mirror the insert case */
548         if (entry->direction == DMA_TO_DEVICE)
549                 return;
550
551         spin_lock_irqsave(&radix_lock, flags);
552         /* since we are counting overlaps the final put of the
553          * cacheline will occur when the overlap count is 0.
554          * active_cacheline_dec_overlap() returns -1 in that case
555          */
556         if (active_cacheline_dec_overlap(cln) < 0)
557                 radix_tree_delete(&dma_active_cacheline, cln);
558         spin_unlock_irqrestore(&radix_lock, flags);
559 }
560
561 /**
562  * debug_dma_assert_idle() - assert that a page is not undergoing dma
563  * @page: page to lookup in the dma_active_cacheline tree
564  *
565  * Place a call to this routine in cases where the cpu touching the page
566  * before the dma completes (page is dma_unmapped) will lead to data
567  * corruption.
568  */
569 void debug_dma_assert_idle(struct page *page)
570 {
571         static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
572         struct dma_debug_entry *entry = NULL;
573         void **results = (void **) &ents;
574         unsigned int nents, i;
575         unsigned long flags;
576         phys_addr_t cln;
577
578         if (dma_debug_disabled())
579                 return;
580
581         if (!page)
582                 return;
583
584         cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
585         spin_lock_irqsave(&radix_lock, flags);
586         nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
587                                        CACHELINES_PER_PAGE);
588         for (i = 0; i < nents; i++) {
589                 phys_addr_t ent_cln = to_cacheline_number(ents[i]);
590
591                 if (ent_cln == cln) {
592                         entry = ents[i];
593                         break;
594                 } else if (ent_cln >= cln + CACHELINES_PER_PAGE)
595                         break;
596         }
597         spin_unlock_irqrestore(&radix_lock, flags);
598
599         if (!entry)
600                 return;
601
602         cln = to_cacheline_number(entry);
603         err_printk(entry->dev, entry,
604                    "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
605                    &cln);
606 }
607
608 /*
609  * Wrapper function for adding an entry to the hash.
610  * This function takes care of locking itself.
611  */
612 static void add_dma_entry(struct dma_debug_entry *entry)
613 {
614         struct hash_bucket *bucket;
615         unsigned long flags;
616         int rc;
617
618         bucket = get_hash_bucket(entry, &flags);
619         hash_bucket_add(bucket, entry);
620         put_hash_bucket(bucket, &flags);
621
622         rc = active_cacheline_insert(entry);
623         if (rc == -ENOMEM) {
624                 pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
625                 global_disable = true;
626         }
627
628         /* TODO: report -EEXIST errors here as overlapping mappings are
629          * not supported by the DMA API
630          */
631 }
632
633 static struct dma_debug_entry *__dma_entry_alloc(void)
634 {
635         struct dma_debug_entry *entry;
636
637         entry = list_entry(free_entries.next, struct dma_debug_entry, list);
638         list_del(&entry->list);
639         memset(entry, 0, sizeof(*entry));
640
641         num_free_entries -= 1;
642         if (num_free_entries < min_free_entries)
643                 min_free_entries = num_free_entries;
644
645         return entry;
646 }
647
648 /* struct dma_entry allocator
649  *
650  * The next two functions implement the allocator for
651  * struct dma_debug_entries.
652  */
653 static struct dma_debug_entry *dma_entry_alloc(void)
654 {
655         struct dma_debug_entry *entry;
656         unsigned long flags;
657
658         spin_lock_irqsave(&free_entries_lock, flags);
659
660         if (list_empty(&free_entries)) {
661                 global_disable = true;
662                 spin_unlock_irqrestore(&free_entries_lock, flags);
663                 pr_err("DMA-API: debugging out of memory - disabling\n");
664                 return NULL;
665         }
666
667         entry = __dma_entry_alloc();
668
669         spin_unlock_irqrestore(&free_entries_lock, flags);
670
671 #ifdef CONFIG_STACKTRACE
672         entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
673         entry->stacktrace.entries = entry->st_entries;
674         entry->stacktrace.skip = 2;
675         save_stack_trace(&entry->stacktrace);
676 #endif
677
678         return entry;
679 }
680
681 static void dma_entry_free(struct dma_debug_entry *entry)
682 {
683         unsigned long flags;
684
685         active_cacheline_remove(entry);
686
687         /*
688          * add to beginning of the list - this way the entries are
689          * more likely cache hot when they are reallocated.
690          */
691         spin_lock_irqsave(&free_entries_lock, flags);
692         list_add(&entry->list, &free_entries);
693         num_free_entries += 1;
694         spin_unlock_irqrestore(&free_entries_lock, flags);
695 }
696
697 int dma_debug_resize_entries(u32 num_entries)
698 {
699         int i, delta, ret = 0;
700         unsigned long flags;
701         struct dma_debug_entry *entry;
702         LIST_HEAD(tmp);
703
704         spin_lock_irqsave(&free_entries_lock, flags);
705
706         if (nr_total_entries < num_entries) {
707                 delta = num_entries - nr_total_entries;
708
709                 spin_unlock_irqrestore(&free_entries_lock, flags);
710
711                 for (i = 0; i < delta; i++) {
712                         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
713                         if (!entry)
714                                 break;
715
716                         list_add_tail(&entry->list, &tmp);
717                 }
718
719                 spin_lock_irqsave(&free_entries_lock, flags);
720
721                 list_splice(&tmp, &free_entries);
722                 nr_total_entries += i;
723                 num_free_entries += i;
724         } else {
725                 delta = nr_total_entries - num_entries;
726
727                 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
728                         entry = __dma_entry_alloc();
729                         kfree(entry);
730                 }
731
732                 nr_total_entries -= i;
733         }
734
735         if (nr_total_entries != num_entries)
736                 ret = 1;
737
738         spin_unlock_irqrestore(&free_entries_lock, flags);
739
740         return ret;
741 }
742 EXPORT_SYMBOL(dma_debug_resize_entries);
743
744 /*
745  * DMA-API debugging init code
746  *
747  * The init code does two things:
748  *   1. Initialize core data structures
749  *   2. Preallocate a given number of dma_debug_entry structs
750  */
751
752 static int prealloc_memory(u32 num_entries)
753 {
754         struct dma_debug_entry *entry, *next_entry;
755         int i;
756
757         for (i = 0; i < num_entries; ++i) {
758                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
759                 if (!entry)
760                         goto out_err;
761
762                 list_add_tail(&entry->list, &free_entries);
763         }
764
765         num_free_entries = num_entries;
766         min_free_entries = num_entries;
767
768         pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
769
770         return 0;
771
772 out_err:
773
774         list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
775                 list_del(&entry->list);
776                 kfree(entry);
777         }
778
779         return -ENOMEM;
780 }
781
782 static ssize_t filter_read(struct file *file, char __user *user_buf,
783                            size_t count, loff_t *ppos)
784 {
785         char buf[NAME_MAX_LEN + 1];
786         unsigned long flags;
787         int len;
788
789         if (!current_driver_name[0])
790                 return 0;
791
792         /*
793          * We can't copy to userspace directly because current_driver_name can
794          * only be read under the driver_name_lock with irqs disabled. So
795          * create a temporary copy first.
796          */
797         read_lock_irqsave(&driver_name_lock, flags);
798         len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
799         read_unlock_irqrestore(&driver_name_lock, flags);
800
801         return simple_read_from_buffer(user_buf, count, ppos, buf, len);
802 }
803
804 static ssize_t filter_write(struct file *file, const char __user *userbuf,
805                             size_t count, loff_t *ppos)
806 {
807         char buf[NAME_MAX_LEN];
808         unsigned long flags;
809         size_t len;
810         int i;
811
812         /*
813          * We can't copy from userspace directly. Access to
814          * current_driver_name is protected with a write_lock with irqs
815          * disabled. Since copy_from_user can fault and may sleep we
816          * need to copy to temporary buffer first
817          */
818         len = min(count, (size_t)(NAME_MAX_LEN - 1));
819         if (copy_from_user(buf, userbuf, len))
820                 return -EFAULT;
821
822         buf[len] = 0;
823
824         write_lock_irqsave(&driver_name_lock, flags);
825
826         /*
827          * Now handle the string we got from userspace very carefully.
828          * The rules are:
829          *         - only use the first token we got
830          *         - token delimiter is everything looking like a space
831          *           character (' ', '\n', '\t' ...)
832          *
833          */
834         if (!isalnum(buf[0])) {
835                 /*
836                  * If the first character userspace gave us is not
837                  * alphanumerical then assume the filter should be
838                  * switched off.
839                  */
840                 if (current_driver_name[0])
841                         pr_info("DMA-API: switching off dma-debug driver filter\n");
842                 current_driver_name[0] = 0;
843                 current_driver = NULL;
844                 goto out_unlock;
845         }
846
847         /*
848          * Now parse out the first token and use it as the name for the
849          * driver to filter for.
850          */
851         for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
852                 current_driver_name[i] = buf[i];
853                 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
854                         break;
855         }
856         current_driver_name[i] = 0;
857         current_driver = NULL;
858
859         pr_info("DMA-API: enable driver filter for driver [%s]\n",
860                 current_driver_name);
861
862 out_unlock:
863         write_unlock_irqrestore(&driver_name_lock, flags);
864
865         return count;
866 }
867
868 static const struct file_operations filter_fops = {
869         .read  = filter_read,
870         .write = filter_write,
871         .llseek = default_llseek,
872 };
873
874 static int dma_debug_fs_init(void)
875 {
876         dma_debug_dent = debugfs_create_dir("dma-api", NULL);
877         if (!dma_debug_dent) {
878                 pr_err("DMA-API: can not create debugfs directory\n");
879                 return -ENOMEM;
880         }
881
882         global_disable_dent = debugfs_create_bool("disabled", 0444,
883                         dma_debug_dent,
884                         &global_disable);
885         if (!global_disable_dent)
886                 goto out_err;
887
888         error_count_dent = debugfs_create_u32("error_count", 0444,
889                         dma_debug_dent, &error_count);
890         if (!error_count_dent)
891                 goto out_err;
892
893         show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
894                         dma_debug_dent,
895                         &show_all_errors);
896         if (!show_all_errors_dent)
897                 goto out_err;
898
899         show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
900                         dma_debug_dent,
901                         &show_num_errors);
902         if (!show_num_errors_dent)
903                 goto out_err;
904
905         num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
906                         dma_debug_dent,
907                         &num_free_entries);
908         if (!num_free_entries_dent)
909                 goto out_err;
910
911         min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
912                         dma_debug_dent,
913                         &min_free_entries);
914         if (!min_free_entries_dent)
915                 goto out_err;
916
917         filter_dent = debugfs_create_file("driver_filter", 0644,
918                                           dma_debug_dent, NULL, &filter_fops);
919         if (!filter_dent)
920                 goto out_err;
921
922         return 0;
923
924 out_err:
925         debugfs_remove_recursive(dma_debug_dent);
926
927         return -ENOMEM;
928 }
929
930 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
931 {
932         struct dma_debug_entry *entry;
933         unsigned long flags;
934         int count = 0, i;
935
936         local_irq_save(flags);
937
938         for (i = 0; i < HASH_SIZE; ++i) {
939                 spin_lock(&dma_entry_hash[i].lock);
940                 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
941                         if (entry->dev == dev) {
942                                 count += 1;
943                                 *out_entry = entry;
944                         }
945                 }
946                 spin_unlock(&dma_entry_hash[i].lock);
947         }
948
949         local_irq_restore(flags);
950
951         return count;
952 }
953
954 static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
955 {
956         struct device *dev = data;
957         struct dma_debug_entry *uninitialized_var(entry);
958         int count;
959
960         if (dma_debug_disabled())
961                 return 0;
962
963         switch (action) {
964         case BUS_NOTIFY_UNBOUND_DRIVER:
965                 count = device_dma_allocations(dev, &entry);
966                 if (count == 0)
967                         break;
968                 err_printk(dev, entry, "DMA-API: device driver has pending "
969                                 "DMA allocations while released from device "
970                                 "[count=%d]\n"
971                                 "One of leaked entries details: "
972                                 "[device address=0x%016llx] [size=%llu bytes] "
973                                 "[mapped with %s] [mapped as %s]\n",
974                         count, entry->dev_addr, entry->size,
975                         dir2name[entry->direction], type2name[entry->type]);
976                 break;
977         default:
978                 break;
979         }
980
981         return 0;
982 }
983
984 void dma_debug_add_bus(struct bus_type *bus)
985 {
986         struct notifier_block *nb;
987
988         if (dma_debug_disabled())
989                 return;
990
991         nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
992         if (nb == NULL) {
993                 pr_err("dma_debug_add_bus: out of memory\n");
994                 return;
995         }
996
997         nb->notifier_call = dma_debug_device_change;
998
999         bus_register_notifier(bus, nb);
1000 }
1001
1002 /*
1003  * Let the architectures decide how many entries should be preallocated.
1004  */
1005 void dma_debug_init(u32 num_entries)
1006 {
1007         int i;
1008
1009         /* Do not use dma_debug_initialized here, since we really want to be
1010          * called to set dma_debug_initialized
1011          */
1012         if (global_disable)
1013                 return;
1014
1015         for (i = 0; i < HASH_SIZE; ++i) {
1016                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
1017                 spin_lock_init(&dma_entry_hash[i].lock);
1018         }
1019
1020         if (dma_debug_fs_init() != 0) {
1021                 pr_err("DMA-API: error creating debugfs entries - disabling\n");
1022                 global_disable = true;
1023
1024                 return;
1025         }
1026
1027         if (req_entries)
1028                 num_entries = req_entries;
1029
1030         if (prealloc_memory(num_entries) != 0) {
1031                 pr_err("DMA-API: debugging out of memory error - disabled\n");
1032                 global_disable = true;
1033
1034                 return;
1035         }
1036
1037         nr_total_entries = num_free_entries;
1038
1039         dma_debug_initialized = true;
1040
1041         pr_info("DMA-API: debugging enabled by kernel config\n");
1042 }
1043
1044 static __init int dma_debug_cmdline(char *str)
1045 {
1046         if (!str)
1047                 return -EINVAL;
1048
1049         if (strncmp(str, "off", 3) == 0) {
1050                 pr_info("DMA-API: debugging disabled on kernel command line\n");
1051                 global_disable = true;
1052         }
1053
1054         return 0;
1055 }
1056
1057 static __init int dma_debug_entries_cmdline(char *str)
1058 {
1059         int res;
1060
1061         if (!str)
1062                 return -EINVAL;
1063
1064         res = get_option(&str, &req_entries);
1065
1066         if (!res)
1067                 req_entries = 0;
1068
1069         return 0;
1070 }
1071
1072 __setup("dma_debug=", dma_debug_cmdline);
1073 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
1074
1075 static void check_unmap(struct dma_debug_entry *ref)
1076 {
1077         struct dma_debug_entry *entry;
1078         struct hash_bucket *bucket;
1079         unsigned long flags;
1080
1081         bucket = get_hash_bucket(ref, &flags);
1082         entry = bucket_find_exact(bucket, ref);
1083
1084         if (!entry) {
1085                 /* must drop lock before calling dma_mapping_error */
1086                 put_hash_bucket(bucket, &flags);
1087
1088                 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
1089                         err_printk(ref->dev, NULL,
1090                                    "DMA-API: device driver tries to free an "
1091                                    "invalid DMA memory address\n");
1092                 } else {
1093                         err_printk(ref->dev, NULL,
1094                                    "DMA-API: device driver tries to free DMA "
1095                                    "memory it has not allocated [device "
1096                                    "address=0x%016llx] [size=%llu bytes]\n",
1097                                    ref->dev_addr, ref->size);
1098                 }
1099                 return;
1100         }
1101
1102         if (ref->size != entry->size) {
1103                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1104                            "DMA memory with different size "
1105                            "[device address=0x%016llx] [map size=%llu bytes] "
1106                            "[unmap size=%llu bytes]\n",
1107                            ref->dev_addr, entry->size, ref->size);
1108         }
1109
1110         if (ref->type != entry->type) {
1111                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1112                            "DMA memory with wrong function "
1113                            "[device address=0x%016llx] [size=%llu bytes] "
1114                            "[mapped as %s] [unmapped as %s]\n",
1115                            ref->dev_addr, ref->size,
1116                            type2name[entry->type], type2name[ref->type]);
1117         } else if ((entry->type == dma_debug_coherent) &&
1118                    (phys_addr(ref) != phys_addr(entry))) {
1119                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1120                            "DMA memory with different CPU address "
1121                            "[device address=0x%016llx] [size=%llu bytes] "
1122                            "[cpu alloc address=0x%016llx] "
1123                            "[cpu free address=0x%016llx]",
1124                            ref->dev_addr, ref->size,
1125                            phys_addr(entry),
1126                            phys_addr(ref));
1127         }
1128
1129         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1130             ref->sg_call_ents != entry->sg_call_ents) {
1131                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1132                            "DMA sg list with different entry count "
1133                            "[map count=%d] [unmap count=%d]\n",
1134                            entry->sg_call_ents, ref->sg_call_ents);
1135         }
1136
1137         /*
1138          * This may be no bug in reality - but most implementations of the
1139          * DMA API don't handle this properly, so check for it here
1140          */
1141         if (ref->direction != entry->direction) {
1142                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1143                            "DMA memory with different direction "
1144                            "[device address=0x%016llx] [size=%llu bytes] "
1145                            "[mapped with %s] [unmapped with %s]\n",
1146                            ref->dev_addr, ref->size,
1147                            dir2name[entry->direction],
1148                            dir2name[ref->direction]);
1149         }
1150
1151         if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1152                 err_printk(ref->dev, entry,
1153                            "DMA-API: device driver failed to check map error"
1154                            "[device address=0x%016llx] [size=%llu bytes] "
1155                            "[mapped as %s]",
1156                            ref->dev_addr, ref->size,
1157                            type2name[entry->type]);
1158         }
1159
1160         hash_bucket_del(entry);
1161         dma_entry_free(entry);
1162
1163         put_hash_bucket(bucket, &flags);
1164 }
1165
1166 static void check_for_stack(struct device *dev, void *addr)
1167 {
1168         if (object_is_on_stack(addr))
1169                 err_printk(dev, NULL, "DMA-API: device driver maps memory from "
1170                                 "stack [addr=%p]\n", addr);
1171 }
1172
1173 static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
1174 {
1175         unsigned long a1 = (unsigned long)addr;
1176         unsigned long b1 = a1 + len;
1177         unsigned long a2 = (unsigned long)start;
1178         unsigned long b2 = (unsigned long)end;
1179
1180         return !(b1 <= a2 || a1 >= b2);
1181 }
1182
1183 static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1184 {
1185         if (overlap(addr, len, _stext, _etext) ||
1186             overlap(addr, len, __start_rodata, __end_rodata))
1187                 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1188 }
1189
1190 static void check_sync(struct device *dev,
1191                        struct dma_debug_entry *ref,
1192                        bool to_cpu)
1193 {
1194         struct dma_debug_entry *entry;
1195         struct hash_bucket *bucket;
1196         unsigned long flags;
1197
1198         bucket = get_hash_bucket(ref, &flags);
1199
1200         entry = bucket_find_contain(&bucket, ref, &flags);
1201
1202         if (!entry) {
1203                 err_printk(dev, NULL, "DMA-API: device driver tries "
1204                                 "to sync DMA memory it has not allocated "
1205                                 "[device address=0x%016llx] [size=%llu bytes]\n",
1206                                 (unsigned long long)ref->dev_addr, ref->size);
1207                 goto out;
1208         }
1209
1210         if (ref->size > entry->size) {
1211                 err_printk(dev, entry, "DMA-API: device driver syncs"
1212                                 " DMA memory outside allocated range "
1213                                 "[device address=0x%016llx] "
1214                                 "[allocation size=%llu bytes] "
1215                                 "[sync offset+size=%llu]\n",
1216                                 entry->dev_addr, entry->size,
1217                                 ref->size);
1218         }
1219
1220         if (entry->direction == DMA_BIDIRECTIONAL)
1221                 goto out;
1222
1223         if (ref->direction != entry->direction) {
1224                 err_printk(dev, entry, "DMA-API: device driver syncs "
1225                                 "DMA memory with different direction "
1226                                 "[device address=0x%016llx] [size=%llu bytes] "
1227                                 "[mapped with %s] [synced with %s]\n",
1228                                 (unsigned long long)ref->dev_addr, entry->size,
1229                                 dir2name[entry->direction],
1230                                 dir2name[ref->direction]);
1231         }
1232
1233         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1234                       !(ref->direction == DMA_TO_DEVICE))
1235                 err_printk(dev, entry, "DMA-API: device driver syncs "
1236                                 "device read-only DMA memory for cpu "
1237                                 "[device address=0x%016llx] [size=%llu bytes] "
1238                                 "[mapped with %s] [synced with %s]\n",
1239                                 (unsigned long long)ref->dev_addr, entry->size,
1240                                 dir2name[entry->direction],
1241                                 dir2name[ref->direction]);
1242
1243         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1244                        !(ref->direction == DMA_FROM_DEVICE))
1245                 err_printk(dev, entry, "DMA-API: device driver syncs "
1246                                 "device write-only DMA memory to device "
1247                                 "[device address=0x%016llx] [size=%llu bytes] "
1248                                 "[mapped with %s] [synced with %s]\n",
1249                                 (unsigned long long)ref->dev_addr, entry->size,
1250                                 dir2name[entry->direction],
1251                                 dir2name[ref->direction]);
1252
1253         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1254             ref->sg_call_ents != entry->sg_call_ents) {
1255                 err_printk(ref->dev, entry, "DMA-API: device driver syncs "
1256                            "DMA sg list with different entry count "
1257                            "[map count=%d] [sync count=%d]\n",
1258                            entry->sg_call_ents, ref->sg_call_ents);
1259         }
1260
1261 out:
1262         put_hash_bucket(bucket, &flags);
1263 }
1264
1265 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1266                         size_t size, int direction, dma_addr_t dma_addr,
1267                         bool map_single)
1268 {
1269         struct dma_debug_entry *entry;
1270
1271         if (unlikely(dma_debug_disabled()))
1272                 return;
1273
1274         if (dma_mapping_error(dev, dma_addr))
1275                 return;
1276
1277         entry = dma_entry_alloc();
1278         if (!entry)
1279                 return;
1280
1281         entry->dev       = dev;
1282         entry->type      = dma_debug_page;
1283         entry->pfn       = page_to_pfn(page);
1284         entry->offset    = offset,
1285         entry->dev_addr  = dma_addr;
1286         entry->size      = size;
1287         entry->direction = direction;
1288         entry->map_err_type = MAP_ERR_NOT_CHECKED;
1289
1290         if (map_single)
1291                 entry->type = dma_debug_single;
1292
1293         if (!PageHighMem(page)) {
1294                 void *addr = page_address(page) + offset;
1295
1296                 check_for_stack(dev, addr);
1297                 check_for_illegal_area(dev, addr, size);
1298         }
1299
1300         add_dma_entry(entry);
1301 }
1302 EXPORT_SYMBOL(debug_dma_map_page);
1303
1304 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1305 {
1306         struct dma_debug_entry ref;
1307         struct dma_debug_entry *entry;
1308         struct hash_bucket *bucket;
1309         unsigned long flags;
1310
1311         if (unlikely(dma_debug_disabled()))
1312                 return;
1313
1314         ref.dev = dev;
1315         ref.dev_addr = dma_addr;
1316         bucket = get_hash_bucket(&ref, &flags);
1317
1318         list_for_each_entry(entry, &bucket->list, list) {
1319                 if (!exact_match(&ref, entry))
1320                         continue;
1321
1322                 /*
1323                  * The same physical address can be mapped multiple
1324                  * times. Without a hardware IOMMU this results in the
1325                  * same device addresses being put into the dma-debug
1326                  * hash multiple times too. This can result in false
1327                  * positives being reported. Therefore we implement a
1328                  * best-fit algorithm here which updates the first entry
1329                  * from the hash which fits the reference value and is
1330                  * not currently listed as being checked.
1331                  */
1332                 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1333                         entry->map_err_type = MAP_ERR_CHECKED;
1334                         break;
1335                 }
1336         }
1337
1338         put_hash_bucket(bucket, &flags);
1339 }
1340 EXPORT_SYMBOL(debug_dma_mapping_error);
1341
1342 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1343                           size_t size, int direction, bool map_single)
1344 {
1345         struct dma_debug_entry ref = {
1346                 .type           = dma_debug_page,
1347                 .dev            = dev,
1348                 .dev_addr       = addr,
1349                 .size           = size,
1350                 .direction      = direction,
1351         };
1352
1353         if (unlikely(dma_debug_disabled()))
1354                 return;
1355
1356         if (map_single)
1357                 ref.type = dma_debug_single;
1358
1359         check_unmap(&ref);
1360 }
1361 EXPORT_SYMBOL(debug_dma_unmap_page);
1362
1363 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1364                       int nents, int mapped_ents, int direction)
1365 {
1366         struct dma_debug_entry *entry;
1367         struct scatterlist *s;
1368         int i;
1369
1370         if (unlikely(dma_debug_disabled()))
1371                 return;
1372
1373         for_each_sg(sg, s, mapped_ents, i) {
1374                 entry = dma_entry_alloc();
1375                 if (!entry)
1376                         return;
1377
1378                 entry->type           = dma_debug_sg;
1379                 entry->dev            = dev;
1380                 entry->pfn            = page_to_pfn(sg_page(s));
1381                 entry->offset         = s->offset,
1382                 entry->size           = sg_dma_len(s);
1383                 entry->dev_addr       = sg_dma_address(s);
1384                 entry->direction      = direction;
1385                 entry->sg_call_ents   = nents;
1386                 entry->sg_mapped_ents = mapped_ents;
1387
1388                 if (!PageHighMem(sg_page(s))) {
1389                         check_for_stack(dev, sg_virt(s));
1390                         check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1391                 }
1392
1393                 add_dma_entry(entry);
1394         }
1395 }
1396 EXPORT_SYMBOL(debug_dma_map_sg);
1397
1398 static int get_nr_mapped_entries(struct device *dev,
1399                                  struct dma_debug_entry *ref)
1400 {
1401         struct dma_debug_entry *entry;
1402         struct hash_bucket *bucket;
1403         unsigned long flags;
1404         int mapped_ents;
1405
1406         bucket       = get_hash_bucket(ref, &flags);
1407         entry        = bucket_find_exact(bucket, ref);
1408         mapped_ents  = 0;
1409
1410         if (entry)
1411                 mapped_ents = entry->sg_mapped_ents;
1412         put_hash_bucket(bucket, &flags);
1413
1414         return mapped_ents;
1415 }
1416
1417 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1418                         int nelems, int dir)
1419 {
1420         struct scatterlist *s;
1421         int mapped_ents = 0, i;
1422
1423         if (unlikely(dma_debug_disabled()))
1424                 return;
1425
1426         for_each_sg(sglist, s, nelems, i) {
1427
1428                 struct dma_debug_entry ref = {
1429                         .type           = dma_debug_sg,
1430                         .dev            = dev,
1431                         .pfn            = page_to_pfn(sg_page(s)),
1432                         .offset         = s->offset,
1433                         .dev_addr       = sg_dma_address(s),
1434                         .size           = sg_dma_len(s),
1435                         .direction      = dir,
1436                         .sg_call_ents   = nelems,
1437                 };
1438
1439                 if (mapped_ents && i >= mapped_ents)
1440                         break;
1441
1442                 if (!i)
1443                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1444
1445                 check_unmap(&ref);
1446         }
1447 }
1448 EXPORT_SYMBOL(debug_dma_unmap_sg);
1449
1450 void debug_dma_alloc_coherent(struct device *dev, size_t size,
1451                               dma_addr_t dma_addr, void *virt)
1452 {
1453         struct dma_debug_entry *entry;
1454
1455         if (unlikely(dma_debug_disabled()))
1456                 return;
1457
1458         if (unlikely(virt == NULL))
1459                 return;
1460
1461         entry = dma_entry_alloc();
1462         if (!entry)
1463                 return;
1464
1465         entry->type      = dma_debug_coherent;
1466         entry->dev       = dev;
1467         entry->pfn       = page_to_pfn(virt_to_page(virt));
1468         entry->offset    = (size_t) virt & ~PAGE_MASK;
1469         entry->size      = size;
1470         entry->dev_addr  = dma_addr;
1471         entry->direction = DMA_BIDIRECTIONAL;
1472
1473         add_dma_entry(entry);
1474 }
1475 EXPORT_SYMBOL(debug_dma_alloc_coherent);
1476
1477 void debug_dma_free_coherent(struct device *dev, size_t size,
1478                          void *virt, dma_addr_t addr)
1479 {
1480         struct dma_debug_entry ref = {
1481                 .type           = dma_debug_coherent,
1482                 .dev            = dev,
1483                 .pfn            = page_to_pfn(virt_to_page(virt)),
1484                 .offset         = (size_t) virt & ~PAGE_MASK,
1485                 .dev_addr       = addr,
1486                 .size           = size,
1487                 .direction      = DMA_BIDIRECTIONAL,
1488         };
1489
1490         if (unlikely(dma_debug_disabled()))
1491                 return;
1492
1493         check_unmap(&ref);
1494 }
1495 EXPORT_SYMBOL(debug_dma_free_coherent);
1496
1497 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1498                                    size_t size, int direction)
1499 {
1500         struct dma_debug_entry ref;
1501
1502         if (unlikely(dma_debug_disabled()))
1503                 return;
1504
1505         ref.type         = dma_debug_single;
1506         ref.dev          = dev;
1507         ref.dev_addr     = dma_handle;
1508         ref.size         = size;
1509         ref.direction    = direction;
1510         ref.sg_call_ents = 0;
1511
1512         check_sync(dev, &ref, true);
1513 }
1514 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1515
1516 void debug_dma_sync_single_for_device(struct device *dev,
1517                                       dma_addr_t dma_handle, size_t size,
1518                                       int direction)
1519 {
1520         struct dma_debug_entry ref;
1521
1522         if (unlikely(dma_debug_disabled()))
1523                 return;
1524
1525         ref.type         = dma_debug_single;
1526         ref.dev          = dev;
1527         ref.dev_addr     = dma_handle;
1528         ref.size         = size;
1529         ref.direction    = direction;
1530         ref.sg_call_ents = 0;
1531
1532         check_sync(dev, &ref, false);
1533 }
1534 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1535
1536 void debug_dma_sync_single_range_for_cpu(struct device *dev,
1537                                          dma_addr_t dma_handle,
1538                                          unsigned long offset, size_t size,
1539                                          int direction)
1540 {
1541         struct dma_debug_entry ref;
1542
1543         if (unlikely(dma_debug_disabled()))
1544                 return;
1545
1546         ref.type         = dma_debug_single;
1547         ref.dev          = dev;
1548         ref.dev_addr     = dma_handle;
1549         ref.size         = offset + size;
1550         ref.direction    = direction;
1551         ref.sg_call_ents = 0;
1552
1553         check_sync(dev, &ref, true);
1554 }
1555 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1556
1557 void debug_dma_sync_single_range_for_device(struct device *dev,
1558                                             dma_addr_t dma_handle,
1559                                             unsigned long offset,
1560                                             size_t size, int direction)
1561 {
1562         struct dma_debug_entry ref;
1563
1564         if (unlikely(dma_debug_disabled()))
1565                 return;
1566
1567         ref.type         = dma_debug_single;
1568         ref.dev          = dev;
1569         ref.dev_addr     = dma_handle;
1570         ref.size         = offset + size;
1571         ref.direction    = direction;
1572         ref.sg_call_ents = 0;
1573
1574         check_sync(dev, &ref, false);
1575 }
1576 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1577
1578 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1579                                int nelems, int direction)
1580 {
1581         struct scatterlist *s;
1582         int mapped_ents = 0, i;
1583
1584         if (unlikely(dma_debug_disabled()))
1585                 return;
1586
1587         for_each_sg(sg, s, nelems, i) {
1588
1589                 struct dma_debug_entry ref = {
1590                         .type           = dma_debug_sg,
1591                         .dev            = dev,
1592                         .pfn            = page_to_pfn(sg_page(s)),
1593                         .offset         = s->offset,
1594                         .dev_addr       = sg_dma_address(s),
1595                         .size           = sg_dma_len(s),
1596                         .direction      = direction,
1597                         .sg_call_ents   = nelems,
1598                 };
1599
1600                 if (!i)
1601                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1602
1603                 if (i >= mapped_ents)
1604                         break;
1605
1606                 check_sync(dev, &ref, true);
1607         }
1608 }
1609 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1610
1611 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1612                                   int nelems, int direction)
1613 {
1614         struct scatterlist *s;
1615         int mapped_ents = 0, i;
1616
1617         if (unlikely(dma_debug_disabled()))
1618                 return;
1619
1620         for_each_sg(sg, s, nelems, i) {
1621
1622                 struct dma_debug_entry ref = {
1623                         .type           = dma_debug_sg,
1624                         .dev            = dev,
1625                         .pfn            = page_to_pfn(sg_page(s)),
1626                         .offset         = s->offset,
1627                         .dev_addr       = sg_dma_address(s),
1628                         .size           = sg_dma_len(s),
1629                         .direction      = direction,
1630                         .sg_call_ents   = nelems,
1631                 };
1632                 if (!i)
1633                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1634
1635                 if (i >= mapped_ents)
1636                         break;
1637
1638                 check_sync(dev, &ref, false);
1639         }
1640 }
1641 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1642
1643 static int __init dma_debug_driver_setup(char *str)
1644 {
1645         int i;
1646
1647         for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1648                 current_driver_name[i] = *str;
1649                 if (*str == 0)
1650                         break;
1651         }
1652
1653         if (current_driver_name[0])
1654                 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1655                         current_driver_name);
1656
1657
1658         return 1;
1659 }
1660 __setup("dma_debug_driver=", dma_debug_driver_setup);