Merge branch 'v4.4/topic/ro-vdso' into linux-linaro-lsk-v4.4
[firefly-linux-kernel-4.4.55.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         }
431 }
432 EXPORT_SYMBOL(debug_dma_dump_mappings);
433
434 /*
435  * For each mapping (initial cacheline in the case of
436  * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
437  * scatterlist, or the cacheline specified in dma_map_single) insert
438  * into this tree using the cacheline as the key. At
439  * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry.  If
440  * the entry already exists at insertion time add a tag as a reference
441  * count for the overlapping mappings.  For now, the overlap tracking
442  * just ensures that 'unmaps' balance 'maps' before marking the
443  * cacheline idle, but we should also be flagging overlaps as an API
444  * violation.
445  *
446  * Memory usage is mostly constrained by the maximum number of available
447  * dma-debug entries in that we need a free dma_debug_entry before
448  * inserting into the tree.  In the case of dma_map_page and
449  * dma_alloc_coherent there is only one dma_debug_entry and one
450  * dma_active_cacheline entry to track per event.  dma_map_sg(), on the
451  * other hand, consumes a single dma_debug_entry, but inserts 'nents'
452  * entries into the tree.
453  *
454  * At any time debug_dma_assert_idle() can be called to trigger a
455  * warning if any cachelines in the given page are in the active set.
456  */
457 static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
458 static DEFINE_SPINLOCK(radix_lock);
459 #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
460 #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
461 #define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
462
463 static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
464 {
465         return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
466                 (entry->offset >> L1_CACHE_SHIFT);
467 }
468
469 static int active_cacheline_read_overlap(phys_addr_t cln)
470 {
471         int overlap = 0, i;
472
473         for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
474                 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
475                         overlap |= 1 << i;
476         return overlap;
477 }
478
479 static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
480 {
481         int i;
482
483         if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
484                 return overlap;
485
486         for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
487                 if (overlap & 1 << i)
488                         radix_tree_tag_set(&dma_active_cacheline, cln, i);
489                 else
490                         radix_tree_tag_clear(&dma_active_cacheline, cln, i);
491
492         return overlap;
493 }
494
495 static void active_cacheline_inc_overlap(phys_addr_t cln)
496 {
497         int overlap = active_cacheline_read_overlap(cln);
498
499         overlap = active_cacheline_set_overlap(cln, ++overlap);
500
501         /* If we overflowed the overlap counter then we're potentially
502          * leaking dma-mappings.  Otherwise, if maps and unmaps are
503          * balanced then this overflow may cause false negatives in
504          * debug_dma_assert_idle() as the cacheline may be marked idle
505          * prematurely.
506          */
507         WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
508                   "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
509                   ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
510 }
511
512 static int active_cacheline_dec_overlap(phys_addr_t cln)
513 {
514         int overlap = active_cacheline_read_overlap(cln);
515
516         return active_cacheline_set_overlap(cln, --overlap);
517 }
518
519 static int active_cacheline_insert(struct dma_debug_entry *entry)
520 {
521         phys_addr_t cln = to_cacheline_number(entry);
522         unsigned long flags;
523         int rc;
524
525         /* If the device is not writing memory then we don't have any
526          * concerns about the cpu consuming stale data.  This mitigates
527          * legitimate usages of overlapping mappings.
528          */
529         if (entry->direction == DMA_TO_DEVICE)
530                 return 0;
531
532         spin_lock_irqsave(&radix_lock, flags);
533         rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
534         if (rc == -EEXIST)
535                 active_cacheline_inc_overlap(cln);
536         spin_unlock_irqrestore(&radix_lock, flags);
537
538         return rc;
539 }
540
541 static void active_cacheline_remove(struct dma_debug_entry *entry)
542 {
543         phys_addr_t cln = to_cacheline_number(entry);
544         unsigned long flags;
545
546         /* ...mirror the insert case */
547         if (entry->direction == DMA_TO_DEVICE)
548                 return;
549
550         spin_lock_irqsave(&radix_lock, flags);
551         /* since we are counting overlaps the final put of the
552          * cacheline will occur when the overlap count is 0.
553          * active_cacheline_dec_overlap() returns -1 in that case
554          */
555         if (active_cacheline_dec_overlap(cln) < 0)
556                 radix_tree_delete(&dma_active_cacheline, cln);
557         spin_unlock_irqrestore(&radix_lock, flags);
558 }
559
560 /**
561  * debug_dma_assert_idle() - assert that a page is not undergoing dma
562  * @page: page to lookup in the dma_active_cacheline tree
563  *
564  * Place a call to this routine in cases where the cpu touching the page
565  * before the dma completes (page is dma_unmapped) will lead to data
566  * corruption.
567  */
568 void debug_dma_assert_idle(struct page *page)
569 {
570         static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
571         struct dma_debug_entry *entry = NULL;
572         void **results = (void **) &ents;
573         unsigned int nents, i;
574         unsigned long flags;
575         phys_addr_t cln;
576
577         if (dma_debug_disabled())
578                 return;
579
580         if (!page)
581                 return;
582
583         cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
584         spin_lock_irqsave(&radix_lock, flags);
585         nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
586                                        CACHELINES_PER_PAGE);
587         for (i = 0; i < nents; i++) {
588                 phys_addr_t ent_cln = to_cacheline_number(ents[i]);
589
590                 if (ent_cln == cln) {
591                         entry = ents[i];
592                         break;
593                 } else if (ent_cln >= cln + CACHELINES_PER_PAGE)
594                         break;
595         }
596         spin_unlock_irqrestore(&radix_lock, flags);
597
598         if (!entry)
599                 return;
600
601         cln = to_cacheline_number(entry);
602         err_printk(entry->dev, entry,
603                    "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
604                    &cln);
605 }
606
607 /*
608  * Wrapper function for adding an entry to the hash.
609  * This function takes care of locking itself.
610  */
611 static void add_dma_entry(struct dma_debug_entry *entry)
612 {
613         struct hash_bucket *bucket;
614         unsigned long flags;
615         int rc;
616
617         bucket = get_hash_bucket(entry, &flags);
618         hash_bucket_add(bucket, entry);
619         put_hash_bucket(bucket, &flags);
620
621         rc = active_cacheline_insert(entry);
622         if (rc == -ENOMEM) {
623                 pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
624                 global_disable = true;
625         }
626
627         /* TODO: report -EEXIST errors here as overlapping mappings are
628          * not supported by the DMA API
629          */
630 }
631
632 static struct dma_debug_entry *__dma_entry_alloc(void)
633 {
634         struct dma_debug_entry *entry;
635
636         entry = list_entry(free_entries.next, struct dma_debug_entry, list);
637         list_del(&entry->list);
638         memset(entry, 0, sizeof(*entry));
639
640         num_free_entries -= 1;
641         if (num_free_entries < min_free_entries)
642                 min_free_entries = num_free_entries;
643
644         return entry;
645 }
646
647 /* struct dma_entry allocator
648  *
649  * The next two functions implement the allocator for
650  * struct dma_debug_entries.
651  */
652 static struct dma_debug_entry *dma_entry_alloc(void)
653 {
654         struct dma_debug_entry *entry;
655         unsigned long flags;
656
657         spin_lock_irqsave(&free_entries_lock, flags);
658
659         if (list_empty(&free_entries)) {
660                 pr_err("DMA-API: debugging out of memory - disabling\n");
661                 global_disable = true;
662                 spin_unlock_irqrestore(&free_entries_lock, flags);
663                 return NULL;
664         }
665
666         entry = __dma_entry_alloc();
667
668         spin_unlock_irqrestore(&free_entries_lock, flags);
669
670 #ifdef CONFIG_STACKTRACE
671         entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
672         entry->stacktrace.entries = entry->st_entries;
673         entry->stacktrace.skip = 2;
674         save_stack_trace(&entry->stacktrace);
675 #endif
676
677         return entry;
678 }
679
680 static void dma_entry_free(struct dma_debug_entry *entry)
681 {
682         unsigned long flags;
683
684         active_cacheline_remove(entry);
685
686         /*
687          * add to beginning of the list - this way the entries are
688          * more likely cache hot when they are reallocated.
689          */
690         spin_lock_irqsave(&free_entries_lock, flags);
691         list_add(&entry->list, &free_entries);
692         num_free_entries += 1;
693         spin_unlock_irqrestore(&free_entries_lock, flags);
694 }
695
696 int dma_debug_resize_entries(u32 num_entries)
697 {
698         int i, delta, ret = 0;
699         unsigned long flags;
700         struct dma_debug_entry *entry;
701         LIST_HEAD(tmp);
702
703         spin_lock_irqsave(&free_entries_lock, flags);
704
705         if (nr_total_entries < num_entries) {
706                 delta = num_entries - nr_total_entries;
707
708                 spin_unlock_irqrestore(&free_entries_lock, flags);
709
710                 for (i = 0; i < delta; i++) {
711                         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
712                         if (!entry)
713                                 break;
714
715                         list_add_tail(&entry->list, &tmp);
716                 }
717
718                 spin_lock_irqsave(&free_entries_lock, flags);
719
720                 list_splice(&tmp, &free_entries);
721                 nr_total_entries += i;
722                 num_free_entries += i;
723         } else {
724                 delta = nr_total_entries - num_entries;
725
726                 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
727                         entry = __dma_entry_alloc();
728                         kfree(entry);
729                 }
730
731                 nr_total_entries -= i;
732         }
733
734         if (nr_total_entries != num_entries)
735                 ret = 1;
736
737         spin_unlock_irqrestore(&free_entries_lock, flags);
738
739         return ret;
740 }
741 EXPORT_SYMBOL(dma_debug_resize_entries);
742
743 /*
744  * DMA-API debugging init code
745  *
746  * The init code does two things:
747  *   1. Initialize core data structures
748  *   2. Preallocate a given number of dma_debug_entry structs
749  */
750
751 static int prealloc_memory(u32 num_entries)
752 {
753         struct dma_debug_entry *entry, *next_entry;
754         int i;
755
756         for (i = 0; i < num_entries; ++i) {
757                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
758                 if (!entry)
759                         goto out_err;
760
761                 list_add_tail(&entry->list, &free_entries);
762         }
763
764         num_free_entries = num_entries;
765         min_free_entries = num_entries;
766
767         pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
768
769         return 0;
770
771 out_err:
772
773         list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
774                 list_del(&entry->list);
775                 kfree(entry);
776         }
777
778         return -ENOMEM;
779 }
780
781 static ssize_t filter_read(struct file *file, char __user *user_buf,
782                            size_t count, loff_t *ppos)
783 {
784         char buf[NAME_MAX_LEN + 1];
785         unsigned long flags;
786         int len;
787
788         if (!current_driver_name[0])
789                 return 0;
790
791         /*
792          * We can't copy to userspace directly because current_driver_name can
793          * only be read under the driver_name_lock with irqs disabled. So
794          * create a temporary copy first.
795          */
796         read_lock_irqsave(&driver_name_lock, flags);
797         len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
798         read_unlock_irqrestore(&driver_name_lock, flags);
799
800         return simple_read_from_buffer(user_buf, count, ppos, buf, len);
801 }
802
803 static ssize_t filter_write(struct file *file, const char __user *userbuf,
804                             size_t count, loff_t *ppos)
805 {
806         char buf[NAME_MAX_LEN];
807         unsigned long flags;
808         size_t len;
809         int i;
810
811         /*
812          * We can't copy from userspace directly. Access to
813          * current_driver_name is protected with a write_lock with irqs
814          * disabled. Since copy_from_user can fault and may sleep we
815          * need to copy to temporary buffer first
816          */
817         len = min(count, (size_t)(NAME_MAX_LEN - 1));
818         if (copy_from_user(buf, userbuf, len))
819                 return -EFAULT;
820
821         buf[len] = 0;
822
823         write_lock_irqsave(&driver_name_lock, flags);
824
825         /*
826          * Now handle the string we got from userspace very carefully.
827          * The rules are:
828          *         - only use the first token we got
829          *         - token delimiter is everything looking like a space
830          *           character (' ', '\n', '\t' ...)
831          *
832          */
833         if (!isalnum(buf[0])) {
834                 /*
835                  * If the first character userspace gave us is not
836                  * alphanumerical then assume the filter should be
837                  * switched off.
838                  */
839                 if (current_driver_name[0])
840                         pr_info("DMA-API: switching off dma-debug driver filter\n");
841                 current_driver_name[0] = 0;
842                 current_driver = NULL;
843                 goto out_unlock;
844         }
845
846         /*
847          * Now parse out the first token and use it as the name for the
848          * driver to filter for.
849          */
850         for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
851                 current_driver_name[i] = buf[i];
852                 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
853                         break;
854         }
855         current_driver_name[i] = 0;
856         current_driver = NULL;
857
858         pr_info("DMA-API: enable driver filter for driver [%s]\n",
859                 current_driver_name);
860
861 out_unlock:
862         write_unlock_irqrestore(&driver_name_lock, flags);
863
864         return count;
865 }
866
867 static const struct file_operations filter_fops = {
868         .read  = filter_read,
869         .write = filter_write,
870         .llseek = default_llseek,
871 };
872
873 static int dma_debug_fs_init(void)
874 {
875         dma_debug_dent = debugfs_create_dir("dma-api", NULL);
876         if (!dma_debug_dent) {
877                 pr_err("DMA-API: can not create debugfs directory\n");
878                 return -ENOMEM;
879         }
880
881         global_disable_dent = debugfs_create_bool("disabled", 0444,
882                         dma_debug_dent,
883                         &global_disable);
884         if (!global_disable_dent)
885                 goto out_err;
886
887         error_count_dent = debugfs_create_u32("error_count", 0444,
888                         dma_debug_dent, &error_count);
889         if (!error_count_dent)
890                 goto out_err;
891
892         show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
893                         dma_debug_dent,
894                         &show_all_errors);
895         if (!show_all_errors_dent)
896                 goto out_err;
897
898         show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
899                         dma_debug_dent,
900                         &show_num_errors);
901         if (!show_num_errors_dent)
902                 goto out_err;
903
904         num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
905                         dma_debug_dent,
906                         &num_free_entries);
907         if (!num_free_entries_dent)
908                 goto out_err;
909
910         min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
911                         dma_debug_dent,
912                         &min_free_entries);
913         if (!min_free_entries_dent)
914                 goto out_err;
915
916         filter_dent = debugfs_create_file("driver_filter", 0644,
917                                           dma_debug_dent, NULL, &filter_fops);
918         if (!filter_dent)
919                 goto out_err;
920
921         return 0;
922
923 out_err:
924         debugfs_remove_recursive(dma_debug_dent);
925
926         return -ENOMEM;
927 }
928
929 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
930 {
931         struct dma_debug_entry *entry;
932         unsigned long flags;
933         int count = 0, i;
934
935         local_irq_save(flags);
936
937         for (i = 0; i < HASH_SIZE; ++i) {
938                 spin_lock(&dma_entry_hash[i].lock);
939                 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
940                         if (entry->dev == dev) {
941                                 count += 1;
942                                 *out_entry = entry;
943                         }
944                 }
945                 spin_unlock(&dma_entry_hash[i].lock);
946         }
947
948         local_irq_restore(flags);
949
950         return count;
951 }
952
953 static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
954 {
955         struct device *dev = data;
956         struct dma_debug_entry *uninitialized_var(entry);
957         int count;
958
959         if (dma_debug_disabled())
960                 return 0;
961
962         switch (action) {
963         case BUS_NOTIFY_UNBOUND_DRIVER:
964                 count = device_dma_allocations(dev, &entry);
965                 if (count == 0)
966                         break;
967                 err_printk(dev, entry, "DMA-API: device driver has pending "
968                                 "DMA allocations while released from device "
969                                 "[count=%d]\n"
970                                 "One of leaked entries details: "
971                                 "[device address=0x%016llx] [size=%llu bytes] "
972                                 "[mapped with %s] [mapped as %s]\n",
973                         count, entry->dev_addr, entry->size,
974                         dir2name[entry->direction], type2name[entry->type]);
975                 break;
976         default:
977                 break;
978         }
979
980         return 0;
981 }
982
983 void dma_debug_add_bus(struct bus_type *bus)
984 {
985         struct notifier_block *nb;
986
987         if (dma_debug_disabled())
988                 return;
989
990         nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
991         if (nb == NULL) {
992                 pr_err("dma_debug_add_bus: out of memory\n");
993                 return;
994         }
995
996         nb->notifier_call = dma_debug_device_change;
997
998         bus_register_notifier(bus, nb);
999 }
1000
1001 /*
1002  * Let the architectures decide how many entries should be preallocated.
1003  */
1004 void dma_debug_init(u32 num_entries)
1005 {
1006         int i;
1007
1008         /* Do not use dma_debug_initialized here, since we really want to be
1009          * called to set dma_debug_initialized
1010          */
1011         if (global_disable)
1012                 return;
1013
1014         for (i = 0; i < HASH_SIZE; ++i) {
1015                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
1016                 spin_lock_init(&dma_entry_hash[i].lock);
1017         }
1018
1019         if (dma_debug_fs_init() != 0) {
1020                 pr_err("DMA-API: error creating debugfs entries - disabling\n");
1021                 global_disable = true;
1022
1023                 return;
1024         }
1025
1026         if (req_entries)
1027                 num_entries = req_entries;
1028
1029         if (prealloc_memory(num_entries) != 0) {
1030                 pr_err("DMA-API: debugging out of memory error - disabled\n");
1031                 global_disable = true;
1032
1033                 return;
1034         }
1035
1036         nr_total_entries = num_free_entries;
1037
1038         dma_debug_initialized = true;
1039
1040         pr_info("DMA-API: debugging enabled by kernel config\n");
1041 }
1042
1043 static __init int dma_debug_cmdline(char *str)
1044 {
1045         if (!str)
1046                 return -EINVAL;
1047
1048         if (strncmp(str, "off", 3) == 0) {
1049                 pr_info("DMA-API: debugging disabled on kernel command line\n");
1050                 global_disable = true;
1051         }
1052
1053         return 0;
1054 }
1055
1056 static __init int dma_debug_entries_cmdline(char *str)
1057 {
1058         int res;
1059
1060         if (!str)
1061                 return -EINVAL;
1062
1063         res = get_option(&str, &req_entries);
1064
1065         if (!res)
1066                 req_entries = 0;
1067
1068         return 0;
1069 }
1070
1071 __setup("dma_debug=", dma_debug_cmdline);
1072 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
1073
1074 static void check_unmap(struct dma_debug_entry *ref)
1075 {
1076         struct dma_debug_entry *entry;
1077         struct hash_bucket *bucket;
1078         unsigned long flags;
1079
1080         bucket = get_hash_bucket(ref, &flags);
1081         entry = bucket_find_exact(bucket, ref);
1082
1083         if (!entry) {
1084                 /* must drop lock before calling dma_mapping_error */
1085                 put_hash_bucket(bucket, &flags);
1086
1087                 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
1088                         err_printk(ref->dev, NULL,
1089                                    "DMA-API: device driver tries to free an "
1090                                    "invalid DMA memory address\n");
1091                 } else {
1092                         err_printk(ref->dev, NULL,
1093                                    "DMA-API: device driver tries to free DMA "
1094                                    "memory it has not allocated [device "
1095                                    "address=0x%016llx] [size=%llu bytes]\n",
1096                                    ref->dev_addr, ref->size);
1097                 }
1098                 return;
1099         }
1100
1101         if (ref->size != entry->size) {
1102                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1103                            "DMA memory with different size "
1104                            "[device address=0x%016llx] [map size=%llu bytes] "
1105                            "[unmap size=%llu bytes]\n",
1106                            ref->dev_addr, entry->size, ref->size);
1107         }
1108
1109         if (ref->type != entry->type) {
1110                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1111                            "DMA memory with wrong function "
1112                            "[device address=0x%016llx] [size=%llu bytes] "
1113                            "[mapped as %s] [unmapped as %s]\n",
1114                            ref->dev_addr, ref->size,
1115                            type2name[entry->type], type2name[ref->type]);
1116         } else if ((entry->type == dma_debug_coherent) &&
1117                    (phys_addr(ref) != phys_addr(entry))) {
1118                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1119                            "DMA memory with different CPU address "
1120                            "[device address=0x%016llx] [size=%llu bytes] "
1121                            "[cpu alloc address=0x%016llx] "
1122                            "[cpu free address=0x%016llx]",
1123                            ref->dev_addr, ref->size,
1124                            phys_addr(entry),
1125                            phys_addr(ref));
1126         }
1127
1128         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1129             ref->sg_call_ents != entry->sg_call_ents) {
1130                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1131                            "DMA sg list with different entry count "
1132                            "[map count=%d] [unmap count=%d]\n",
1133                            entry->sg_call_ents, ref->sg_call_ents);
1134         }
1135
1136         /*
1137          * This may be no bug in reality - but most implementations of the
1138          * DMA API don't handle this properly, so check for it here
1139          */
1140         if (ref->direction != entry->direction) {
1141                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1142                            "DMA memory with different direction "
1143                            "[device address=0x%016llx] [size=%llu bytes] "
1144                            "[mapped with %s] [unmapped with %s]\n",
1145                            ref->dev_addr, ref->size,
1146                            dir2name[entry->direction],
1147                            dir2name[ref->direction]);
1148         }
1149
1150         if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1151                 err_printk(ref->dev, entry,
1152                            "DMA-API: device driver failed to check map error"
1153                            "[device address=0x%016llx] [size=%llu bytes] "
1154                            "[mapped as %s]",
1155                            ref->dev_addr, ref->size,
1156                            type2name[entry->type]);
1157         }
1158
1159         hash_bucket_del(entry);
1160         dma_entry_free(entry);
1161
1162         put_hash_bucket(bucket, &flags);
1163 }
1164
1165 static void check_for_stack(struct device *dev, void *addr)
1166 {
1167         if (object_is_on_stack(addr))
1168                 err_printk(dev, NULL, "DMA-API: device driver maps memory from "
1169                                 "stack [addr=%p]\n", addr);
1170 }
1171
1172 static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
1173 {
1174         unsigned long a1 = (unsigned long)addr;
1175         unsigned long b1 = a1 + len;
1176         unsigned long a2 = (unsigned long)start;
1177         unsigned long b2 = (unsigned long)end;
1178
1179         return !(b1 <= a2 || a1 >= b2);
1180 }
1181
1182 static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1183 {
1184         if (overlap(addr, len, _stext, _etext) ||
1185             overlap(addr, len, __start_rodata, __end_rodata))
1186                 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1187 }
1188
1189 static void check_sync(struct device *dev,
1190                        struct dma_debug_entry *ref,
1191                        bool to_cpu)
1192 {
1193         struct dma_debug_entry *entry;
1194         struct hash_bucket *bucket;
1195         unsigned long flags;
1196
1197         bucket = get_hash_bucket(ref, &flags);
1198
1199         entry = bucket_find_contain(&bucket, ref, &flags);
1200
1201         if (!entry) {
1202                 err_printk(dev, NULL, "DMA-API: device driver tries "
1203                                 "to sync DMA memory it has not allocated "
1204                                 "[device address=0x%016llx] [size=%llu bytes]\n",
1205                                 (unsigned long long)ref->dev_addr, ref->size);
1206                 goto out;
1207         }
1208
1209         if (ref->size > entry->size) {
1210                 err_printk(dev, entry, "DMA-API: device driver syncs"
1211                                 " DMA memory outside allocated range "
1212                                 "[device address=0x%016llx] "
1213                                 "[allocation size=%llu bytes] "
1214                                 "[sync offset+size=%llu]\n",
1215                                 entry->dev_addr, entry->size,
1216                                 ref->size);
1217         }
1218
1219         if (entry->direction == DMA_BIDIRECTIONAL)
1220                 goto out;
1221
1222         if (ref->direction != entry->direction) {
1223                 err_printk(dev, entry, "DMA-API: device driver syncs "
1224                                 "DMA memory with different direction "
1225                                 "[device address=0x%016llx] [size=%llu bytes] "
1226                                 "[mapped with %s] [synced with %s]\n",
1227                                 (unsigned long long)ref->dev_addr, entry->size,
1228                                 dir2name[entry->direction],
1229                                 dir2name[ref->direction]);
1230         }
1231
1232         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1233                       !(ref->direction == DMA_TO_DEVICE))
1234                 err_printk(dev, entry, "DMA-API: device driver syncs "
1235                                 "device read-only DMA memory for cpu "
1236                                 "[device address=0x%016llx] [size=%llu bytes] "
1237                                 "[mapped with %s] [synced with %s]\n",
1238                                 (unsigned long long)ref->dev_addr, entry->size,
1239                                 dir2name[entry->direction],
1240                                 dir2name[ref->direction]);
1241
1242         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1243                        !(ref->direction == DMA_FROM_DEVICE))
1244                 err_printk(dev, entry, "DMA-API: device driver syncs "
1245                                 "device write-only DMA memory to device "
1246                                 "[device address=0x%016llx] [size=%llu bytes] "
1247                                 "[mapped with %s] [synced with %s]\n",
1248                                 (unsigned long long)ref->dev_addr, entry->size,
1249                                 dir2name[entry->direction],
1250                                 dir2name[ref->direction]);
1251
1252         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1253             ref->sg_call_ents != entry->sg_call_ents) {
1254                 err_printk(ref->dev, entry, "DMA-API: device driver syncs "
1255                            "DMA sg list with different entry count "
1256                            "[map count=%d] [sync count=%d]\n",
1257                            entry->sg_call_ents, ref->sg_call_ents);
1258         }
1259
1260 out:
1261         put_hash_bucket(bucket, &flags);
1262 }
1263
1264 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1265                         size_t size, int direction, dma_addr_t dma_addr,
1266                         bool map_single)
1267 {
1268         struct dma_debug_entry *entry;
1269
1270         if (unlikely(dma_debug_disabled()))
1271                 return;
1272
1273         if (dma_mapping_error(dev, dma_addr))
1274                 return;
1275
1276         entry = dma_entry_alloc();
1277         if (!entry)
1278                 return;
1279
1280         entry->dev       = dev;
1281         entry->type      = dma_debug_page;
1282         entry->pfn       = page_to_pfn(page);
1283         entry->offset    = offset,
1284         entry->dev_addr  = dma_addr;
1285         entry->size      = size;
1286         entry->direction = direction;
1287         entry->map_err_type = MAP_ERR_NOT_CHECKED;
1288
1289         if (map_single)
1290                 entry->type = dma_debug_single;
1291
1292         if (!PageHighMem(page)) {
1293                 void *addr = page_address(page) + offset;
1294
1295                 check_for_stack(dev, addr);
1296                 check_for_illegal_area(dev, addr, size);
1297         }
1298
1299         add_dma_entry(entry);
1300 }
1301 EXPORT_SYMBOL(debug_dma_map_page);
1302
1303 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1304 {
1305         struct dma_debug_entry ref;
1306         struct dma_debug_entry *entry;
1307         struct hash_bucket *bucket;
1308         unsigned long flags;
1309
1310         if (unlikely(dma_debug_disabled()))
1311                 return;
1312
1313         ref.dev = dev;
1314         ref.dev_addr = dma_addr;
1315         bucket = get_hash_bucket(&ref, &flags);
1316
1317         list_for_each_entry(entry, &bucket->list, list) {
1318                 if (!exact_match(&ref, entry))
1319                         continue;
1320
1321                 /*
1322                  * The same physical address can be mapped multiple
1323                  * times. Without a hardware IOMMU this results in the
1324                  * same device addresses being put into the dma-debug
1325                  * hash multiple times too. This can result in false
1326                  * positives being reported. Therefore we implement a
1327                  * best-fit algorithm here which updates the first entry
1328                  * from the hash which fits the reference value and is
1329                  * not currently listed as being checked.
1330                  */
1331                 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1332                         entry->map_err_type = MAP_ERR_CHECKED;
1333                         break;
1334                 }
1335         }
1336
1337         put_hash_bucket(bucket, &flags);
1338 }
1339 EXPORT_SYMBOL(debug_dma_mapping_error);
1340
1341 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1342                           size_t size, int direction, bool map_single)
1343 {
1344         struct dma_debug_entry ref = {
1345                 .type           = dma_debug_page,
1346                 .dev            = dev,
1347                 .dev_addr       = addr,
1348                 .size           = size,
1349                 .direction      = direction,
1350         };
1351
1352         if (unlikely(dma_debug_disabled()))
1353                 return;
1354
1355         if (map_single)
1356                 ref.type = dma_debug_single;
1357
1358         check_unmap(&ref);
1359 }
1360 EXPORT_SYMBOL(debug_dma_unmap_page);
1361
1362 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1363                       int nents, int mapped_ents, int direction)
1364 {
1365         struct dma_debug_entry *entry;
1366         struct scatterlist *s;
1367         int i;
1368
1369         if (unlikely(dma_debug_disabled()))
1370                 return;
1371
1372         for_each_sg(sg, s, mapped_ents, i) {
1373                 entry = dma_entry_alloc();
1374                 if (!entry)
1375                         return;
1376
1377                 entry->type           = dma_debug_sg;
1378                 entry->dev            = dev;
1379                 entry->pfn            = page_to_pfn(sg_page(s));
1380                 entry->offset         = s->offset,
1381                 entry->size           = sg_dma_len(s);
1382                 entry->dev_addr       = sg_dma_address(s);
1383                 entry->direction      = direction;
1384                 entry->sg_call_ents   = nents;
1385                 entry->sg_mapped_ents = mapped_ents;
1386
1387                 if (!PageHighMem(sg_page(s))) {
1388                         check_for_stack(dev, sg_virt(s));
1389                         check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1390                 }
1391
1392                 add_dma_entry(entry);
1393         }
1394 }
1395 EXPORT_SYMBOL(debug_dma_map_sg);
1396
1397 static int get_nr_mapped_entries(struct device *dev,
1398                                  struct dma_debug_entry *ref)
1399 {
1400         struct dma_debug_entry *entry;
1401         struct hash_bucket *bucket;
1402         unsigned long flags;
1403         int mapped_ents;
1404
1405         bucket       = get_hash_bucket(ref, &flags);
1406         entry        = bucket_find_exact(bucket, ref);
1407         mapped_ents  = 0;
1408
1409         if (entry)
1410                 mapped_ents = entry->sg_mapped_ents;
1411         put_hash_bucket(bucket, &flags);
1412
1413         return mapped_ents;
1414 }
1415
1416 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1417                         int nelems, int dir)
1418 {
1419         struct scatterlist *s;
1420         int mapped_ents = 0, i;
1421
1422         if (unlikely(dma_debug_disabled()))
1423                 return;
1424
1425         for_each_sg(sglist, s, nelems, i) {
1426
1427                 struct dma_debug_entry ref = {
1428                         .type           = dma_debug_sg,
1429                         .dev            = dev,
1430                         .pfn            = page_to_pfn(sg_page(s)),
1431                         .offset         = s->offset,
1432                         .dev_addr       = sg_dma_address(s),
1433                         .size           = sg_dma_len(s),
1434                         .direction      = dir,
1435                         .sg_call_ents   = nelems,
1436                 };
1437
1438                 if (mapped_ents && i >= mapped_ents)
1439                         break;
1440
1441                 if (!i)
1442                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1443
1444                 check_unmap(&ref);
1445         }
1446 }
1447 EXPORT_SYMBOL(debug_dma_unmap_sg);
1448
1449 void debug_dma_alloc_coherent(struct device *dev, size_t size,
1450                               dma_addr_t dma_addr, void *virt)
1451 {
1452         struct dma_debug_entry *entry;
1453
1454         if (unlikely(dma_debug_disabled()))
1455                 return;
1456
1457         if (unlikely(virt == NULL))
1458                 return;
1459
1460         entry = dma_entry_alloc();
1461         if (!entry)
1462                 return;
1463
1464         entry->type      = dma_debug_coherent;
1465         entry->dev       = dev;
1466         entry->pfn       = page_to_pfn(virt_to_page(virt));
1467         entry->offset    = (size_t) virt & ~PAGE_MASK;
1468         entry->size      = size;
1469         entry->dev_addr  = dma_addr;
1470         entry->direction = DMA_BIDIRECTIONAL;
1471
1472         add_dma_entry(entry);
1473 }
1474 EXPORT_SYMBOL(debug_dma_alloc_coherent);
1475
1476 void debug_dma_free_coherent(struct device *dev, size_t size,
1477                          void *virt, dma_addr_t addr)
1478 {
1479         struct dma_debug_entry ref = {
1480                 .type           = dma_debug_coherent,
1481                 .dev            = dev,
1482                 .pfn            = page_to_pfn(virt_to_page(virt)),
1483                 .offset         = (size_t) virt & ~PAGE_MASK,
1484                 .dev_addr       = addr,
1485                 .size           = size,
1486                 .direction      = DMA_BIDIRECTIONAL,
1487         };
1488
1489         if (unlikely(dma_debug_disabled()))
1490                 return;
1491
1492         check_unmap(&ref);
1493 }
1494 EXPORT_SYMBOL(debug_dma_free_coherent);
1495
1496 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1497                                    size_t size, int direction)
1498 {
1499         struct dma_debug_entry ref;
1500
1501         if (unlikely(dma_debug_disabled()))
1502                 return;
1503
1504         ref.type         = dma_debug_single;
1505         ref.dev          = dev;
1506         ref.dev_addr     = dma_handle;
1507         ref.size         = size;
1508         ref.direction    = direction;
1509         ref.sg_call_ents = 0;
1510
1511         check_sync(dev, &ref, true);
1512 }
1513 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1514
1515 void debug_dma_sync_single_for_device(struct device *dev,
1516                                       dma_addr_t dma_handle, size_t size,
1517                                       int direction)
1518 {
1519         struct dma_debug_entry ref;
1520
1521         if (unlikely(dma_debug_disabled()))
1522                 return;
1523
1524         ref.type         = dma_debug_single;
1525         ref.dev          = dev;
1526         ref.dev_addr     = dma_handle;
1527         ref.size         = size;
1528         ref.direction    = direction;
1529         ref.sg_call_ents = 0;
1530
1531         check_sync(dev, &ref, false);
1532 }
1533 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1534
1535 void debug_dma_sync_single_range_for_cpu(struct device *dev,
1536                                          dma_addr_t dma_handle,
1537                                          unsigned long offset, size_t size,
1538                                          int direction)
1539 {
1540         struct dma_debug_entry ref;
1541
1542         if (unlikely(dma_debug_disabled()))
1543                 return;
1544
1545         ref.type         = dma_debug_single;
1546         ref.dev          = dev;
1547         ref.dev_addr     = dma_handle;
1548         ref.size         = offset + size;
1549         ref.direction    = direction;
1550         ref.sg_call_ents = 0;
1551
1552         check_sync(dev, &ref, true);
1553 }
1554 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1555
1556 void debug_dma_sync_single_range_for_device(struct device *dev,
1557                                             dma_addr_t dma_handle,
1558                                             unsigned long offset,
1559                                             size_t size, int direction)
1560 {
1561         struct dma_debug_entry ref;
1562
1563         if (unlikely(dma_debug_disabled()))
1564                 return;
1565
1566         ref.type         = dma_debug_single;
1567         ref.dev          = dev;
1568         ref.dev_addr     = dma_handle;
1569         ref.size         = offset + size;
1570         ref.direction    = direction;
1571         ref.sg_call_ents = 0;
1572
1573         check_sync(dev, &ref, false);
1574 }
1575 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1576
1577 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1578                                int nelems, int direction)
1579 {
1580         struct scatterlist *s;
1581         int mapped_ents = 0, i;
1582
1583         if (unlikely(dma_debug_disabled()))
1584                 return;
1585
1586         for_each_sg(sg, s, nelems, i) {
1587
1588                 struct dma_debug_entry ref = {
1589                         .type           = dma_debug_sg,
1590                         .dev            = dev,
1591                         .pfn            = page_to_pfn(sg_page(s)),
1592                         .offset         = s->offset,
1593                         .dev_addr       = sg_dma_address(s),
1594                         .size           = sg_dma_len(s),
1595                         .direction      = direction,
1596                         .sg_call_ents   = nelems,
1597                 };
1598
1599                 if (!i)
1600                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1601
1602                 if (i >= mapped_ents)
1603                         break;
1604
1605                 check_sync(dev, &ref, true);
1606         }
1607 }
1608 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1609
1610 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1611                                   int nelems, int direction)
1612 {
1613         struct scatterlist *s;
1614         int mapped_ents = 0, i;
1615
1616         if (unlikely(dma_debug_disabled()))
1617                 return;
1618
1619         for_each_sg(sg, s, nelems, i) {
1620
1621                 struct dma_debug_entry ref = {
1622                         .type           = dma_debug_sg,
1623                         .dev            = dev,
1624                         .pfn            = page_to_pfn(sg_page(s)),
1625                         .offset         = s->offset,
1626                         .dev_addr       = sg_dma_address(s),
1627                         .size           = sg_dma_len(s),
1628                         .direction      = direction,
1629                         .sg_call_ents   = nelems,
1630                 };
1631                 if (!i)
1632                         mapped_ents = get_nr_mapped_entries(dev, &ref);
1633
1634                 if (i >= mapped_ents)
1635                         break;
1636
1637                 check_sync(dev, &ref, false);
1638         }
1639 }
1640 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1641
1642 static int __init dma_debug_driver_setup(char *str)
1643 {
1644         int i;
1645
1646         for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1647                 current_driver_name[i] = *str;
1648                 if (*str == 0)
1649                         break;
1650         }
1651
1652         if (current_driver_name[0])
1653                 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1654                         current_driver_name);
1655
1656
1657         return 1;
1658 }
1659 __setup("dma_debug_driver=", dma_debug_driver_setup);