This source file includes following definitions.
- dma_debug_disabled
- dump_entry_trace
- driver_filter
- hash_fn
- get_hash_bucket
- put_hash_bucket
- exact_match
- containing_match
- __hash_bucket_find
- bucket_find_exact
- bucket_find_contain
- hash_bucket_add
- hash_bucket_del
- phys_addr
- debug_dma_dump_mappings
- to_cacheline_number
- active_cacheline_read_overlap
- active_cacheline_set_overlap
- active_cacheline_inc_overlap
- active_cacheline_dec_overlap
- active_cacheline_insert
- active_cacheline_remove
- debug_dma_assert_idle
- add_dma_entry
- dma_debug_create_entries
- __dma_entry_alloc
- __dma_entry_alloc_check_leak
- dma_entry_alloc
- dma_entry_free
- filter_read
- filter_write
- dump_show
- dma_debug_fs_init
- device_dma_allocations
- dma_debug_device_change
- dma_debug_add_bus
- dma_debug_init
- dma_debug_cmdline
- dma_debug_entries_cmdline
- check_unmap
- check_for_stack
- overlap
- check_for_illegal_area
- check_sync
- check_sg_segment
- debug_dma_map_single
- debug_dma_map_page
- debug_dma_mapping_error
- debug_dma_unmap_page
- debug_dma_map_sg
- get_nr_mapped_entries
- debug_dma_unmap_sg
- debug_dma_alloc_coherent
- debug_dma_free_coherent
- debug_dma_map_resource
- debug_dma_unmap_resource
- debug_dma_sync_single_for_cpu
- debug_dma_sync_single_for_device
- debug_dma_sync_sg_for_cpu
- debug_dma_sync_sg_for_device
- dma_debug_driver_setup
1
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5
6
7
8 #define pr_fmt(fmt) "DMA-API: " fmt
9
10 #include <linux/sched/task_stack.h>
11 #include <linux/scatterlist.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/sched/task.h>
14 #include <linux/stacktrace.h>
15 #include <linux/dma-debug.h>
16 #include <linux/spinlock.h>
17 #include <linux/vmalloc.h>
18 #include <linux/debugfs.h>
19 #include <linux/uaccess.h>
20 #include <linux/export.h>
21 #include <linux/device.h>
22 #include <linux/types.h>
23 #include <linux/sched.h>
24 #include <linux/ctype.h>
25 #include <linux/list.h>
26 #include <linux/slab.h>
27
28 #include <asm/sections.h>
29
30 #define HASH_SIZE 1024ULL
31 #define HASH_FN_SHIFT 13
32 #define HASH_FN_MASK (HASH_SIZE - 1)
33
34 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
35
36 #define DMA_DEBUG_DYNAMIC_ENTRIES (PAGE_SIZE / sizeof(struct dma_debug_entry))
37
38 enum {
39 dma_debug_single,
40 dma_debug_sg,
41 dma_debug_coherent,
42 dma_debug_resource,
43 };
44
45 enum map_err_types {
46 MAP_ERR_CHECK_NOT_APPLICABLE,
47 MAP_ERR_NOT_CHECKED,
48 MAP_ERR_CHECKED,
49 };
50
51 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
52
53
54
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56
57
58
59
60
61
62
63
64
65
66
67 struct dma_debug_entry {
68 struct list_head list;
69 struct device *dev;
70 int type;
71 unsigned long pfn;
72 size_t offset;
73 u64 dev_addr;
74 u64 size;
75 int direction;
76 int sg_call_ents;
77 int sg_mapped_ents;
78 enum map_err_types map_err_type;
79 #ifdef CONFIG_STACKTRACE
80 unsigned int stack_len;
81 unsigned long stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
82 #endif
83 };
84
85 typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
86
87 struct hash_bucket {
88 struct list_head list;
89 spinlock_t lock;
90 } ____cacheline_aligned_in_smp;
91
92
93 static struct hash_bucket dma_entry_hash[HASH_SIZE];
94
95 static LIST_HEAD(free_entries);
96
97 static DEFINE_SPINLOCK(free_entries_lock);
98
99
100 static bool global_disable __read_mostly;
101
102
103 static bool dma_debug_initialized __read_mostly;
104
105 static inline bool dma_debug_disabled(void)
106 {
107 return global_disable || !dma_debug_initialized;
108 }
109
110
111 static u32 error_count;
112
113
114 static u32 show_all_errors __read_mostly;
115
116 static u32 show_num_errors = 1;
117
118 static u32 num_free_entries;
119 static u32 min_free_entries;
120 static u32 nr_total_entries;
121
122
123 static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
124
125
126
127 #define NAME_MAX_LEN 64
128
129 static char current_driver_name[NAME_MAX_LEN] __read_mostly;
130 static struct device_driver *current_driver __read_mostly;
131
132 static DEFINE_RWLOCK(driver_name_lock);
133
134 static const char *const maperr2str[] = {
135 [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
136 [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
137 [MAP_ERR_CHECKED] = "dma map error checked",
138 };
139
140 static const char *type2name[] = {
141 [dma_debug_single] = "single",
142 [dma_debug_sg] = "scather-gather",
143 [dma_debug_coherent] = "coherent",
144 [dma_debug_resource] = "resource",
145 };
146
147 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
148 "DMA_FROM_DEVICE", "DMA_NONE" };
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163 static inline void dump_entry_trace(struct dma_debug_entry *entry)
164 {
165 #ifdef CONFIG_STACKTRACE
166 if (entry) {
167 pr_warning("Mapped at:\n");
168 stack_trace_print(entry->stack_entries, entry->stack_len, 0);
169 }
170 #endif
171 }
172
173 static bool driver_filter(struct device *dev)
174 {
175 struct device_driver *drv;
176 unsigned long flags;
177 bool ret;
178
179
180 if (likely(!current_driver_name[0]))
181 return true;
182
183
184 if (current_driver && dev && dev->driver == current_driver)
185 return true;
186
187
188 if (!dev)
189 return false;
190
191 if (current_driver || !current_driver_name[0])
192 return false;
193
194
195 drv = dev->driver;
196 if (!drv)
197 return false;
198
199
200 read_lock_irqsave(&driver_name_lock, flags);
201
202 ret = false;
203 if (drv->name &&
204 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
205 current_driver = drv;
206 ret = true;
207 }
208
209 read_unlock_irqrestore(&driver_name_lock, flags);
210
211 return ret;
212 }
213
214 #define err_printk(dev, entry, format, arg...) do { \
215 error_count += 1; \
216 if (driver_filter(dev) && \
217 (show_all_errors || show_num_errors > 0)) { \
218 WARN(1, pr_fmt("%s %s: ") format, \
219 dev ? dev_driver_string(dev) : "NULL", \
220 dev ? dev_name(dev) : "NULL", ## arg); \
221 dump_entry_trace(entry); \
222 } \
223 if (!show_all_errors && show_num_errors > 0) \
224 show_num_errors -= 1; \
225 } while (0);
226
227
228
229
230
231
232
233 static int hash_fn(struct dma_debug_entry *entry)
234 {
235
236
237
238
239 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
240 }
241
242
243
244
245 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
246 unsigned long *flags)
247 __acquires(&dma_entry_hash[idx].lock)
248 {
249 int idx = hash_fn(entry);
250 unsigned long __flags;
251
252 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
253 *flags = __flags;
254 return &dma_entry_hash[idx];
255 }
256
257
258
259
260 static void put_hash_bucket(struct hash_bucket *bucket,
261 unsigned long *flags)
262 __releases(&bucket->lock)
263 {
264 unsigned long __flags = *flags;
265
266 spin_unlock_irqrestore(&bucket->lock, __flags);
267 }
268
269 static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
270 {
271 return ((a->dev_addr == b->dev_addr) &&
272 (a->dev == b->dev)) ? true : false;
273 }
274
275 static bool containing_match(struct dma_debug_entry *a,
276 struct dma_debug_entry *b)
277 {
278 if (a->dev != b->dev)
279 return false;
280
281 if ((b->dev_addr <= a->dev_addr) &&
282 ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
283 return true;
284
285 return false;
286 }
287
288
289
290
291 static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
292 struct dma_debug_entry *ref,
293 match_fn match)
294 {
295 struct dma_debug_entry *entry, *ret = NULL;
296 int matches = 0, match_lvl, last_lvl = -1;
297
298 list_for_each_entry(entry, &bucket->list, list) {
299 if (!match(ref, entry))
300 continue;
301
302
303
304
305
306
307
308
309
310
311
312 matches += 1;
313 match_lvl = 0;
314 entry->size == ref->size ? ++match_lvl : 0;
315 entry->type == ref->type ? ++match_lvl : 0;
316 entry->direction == ref->direction ? ++match_lvl : 0;
317 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
318
319 if (match_lvl == 4) {
320
321 return entry;
322 } else if (match_lvl > last_lvl) {
323
324
325
326
327 last_lvl = match_lvl;
328 ret = entry;
329 }
330 }
331
332
333
334
335
336 ret = (matches == 1) ? ret : NULL;
337
338 return ret;
339 }
340
341 static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
342 struct dma_debug_entry *ref)
343 {
344 return __hash_bucket_find(bucket, ref, exact_match);
345 }
346
347 static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
348 struct dma_debug_entry *ref,
349 unsigned long *flags)
350 {
351
352 unsigned int max_range = dma_get_max_seg_size(ref->dev);
353 struct dma_debug_entry *entry, index = *ref;
354 unsigned int range = 0;
355
356 while (range <= max_range) {
357 entry = __hash_bucket_find(*bucket, ref, containing_match);
358
359 if (entry)
360 return entry;
361
362
363
364
365 put_hash_bucket(*bucket, flags);
366 range += (1 << HASH_FN_SHIFT);
367 index.dev_addr -= (1 << HASH_FN_SHIFT);
368 *bucket = get_hash_bucket(&index, flags);
369 }
370
371 return NULL;
372 }
373
374
375
376
377 static void hash_bucket_add(struct hash_bucket *bucket,
378 struct dma_debug_entry *entry)
379 {
380 list_add_tail(&entry->list, &bucket->list);
381 }
382
383
384
385
386 static void hash_bucket_del(struct dma_debug_entry *entry)
387 {
388 list_del(&entry->list);
389 }
390
391 static unsigned long long phys_addr(struct dma_debug_entry *entry)
392 {
393 if (entry->type == dma_debug_resource)
394 return __pfn_to_phys(entry->pfn) + entry->offset;
395
396 return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
397 }
398
399
400
401
402 void debug_dma_dump_mappings(struct device *dev)
403 {
404 int idx;
405
406 for (idx = 0; idx < HASH_SIZE; idx++) {
407 struct hash_bucket *bucket = &dma_entry_hash[idx];
408 struct dma_debug_entry *entry;
409 unsigned long flags;
410
411 spin_lock_irqsave(&bucket->lock, flags);
412
413 list_for_each_entry(entry, &bucket->list, list) {
414 if (!dev || dev == entry->dev) {
415 dev_info(entry->dev,
416 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
417 type2name[entry->type], idx,
418 phys_addr(entry), entry->pfn,
419 entry->dev_addr, entry->size,
420 dir2name[entry->direction],
421 maperr2str[entry->map_err_type]);
422 }
423 }
424
425 spin_unlock_irqrestore(&bucket->lock, flags);
426 cond_resched();
427 }
428 }
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453 static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
454 static DEFINE_SPINLOCK(radix_lock);
455 #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
456 #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
457 #define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
458
459 static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
460 {
461 return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
462 (entry->offset >> L1_CACHE_SHIFT);
463 }
464
465 static int active_cacheline_read_overlap(phys_addr_t cln)
466 {
467 int overlap = 0, i;
468
469 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
470 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
471 overlap |= 1 << i;
472 return overlap;
473 }
474
475 static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
476 {
477 int i;
478
479 if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
480 return overlap;
481
482 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
483 if (overlap & 1 << i)
484 radix_tree_tag_set(&dma_active_cacheline, cln, i);
485 else
486 radix_tree_tag_clear(&dma_active_cacheline, cln, i);
487
488 return overlap;
489 }
490
491 static void active_cacheline_inc_overlap(phys_addr_t cln)
492 {
493 int overlap = active_cacheline_read_overlap(cln);
494
495 overlap = active_cacheline_set_overlap(cln, ++overlap);
496
497
498
499
500
501
502
503 WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
504 pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
505 ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
506 }
507
508 static int active_cacheline_dec_overlap(phys_addr_t cln)
509 {
510 int overlap = active_cacheline_read_overlap(cln);
511
512 return active_cacheline_set_overlap(cln, --overlap);
513 }
514
515 static int active_cacheline_insert(struct dma_debug_entry *entry)
516 {
517 phys_addr_t cln = to_cacheline_number(entry);
518 unsigned long flags;
519 int rc;
520
521
522
523
524
525 if (entry->direction == DMA_TO_DEVICE)
526 return 0;
527
528 spin_lock_irqsave(&radix_lock, flags);
529 rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
530 if (rc == -EEXIST)
531 active_cacheline_inc_overlap(cln);
532 spin_unlock_irqrestore(&radix_lock, flags);
533
534 return rc;
535 }
536
537 static void active_cacheline_remove(struct dma_debug_entry *entry)
538 {
539 phys_addr_t cln = to_cacheline_number(entry);
540 unsigned long flags;
541
542
543 if (entry->direction == DMA_TO_DEVICE)
544 return;
545
546 spin_lock_irqsave(&radix_lock, flags);
547
548
549
550
551 if (active_cacheline_dec_overlap(cln) < 0)
552 radix_tree_delete(&dma_active_cacheline, cln);
553 spin_unlock_irqrestore(&radix_lock, flags);
554 }
555
556
557
558
559
560
561
562
563
564 void debug_dma_assert_idle(struct page *page)
565 {
566 static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
567 struct dma_debug_entry *entry = NULL;
568 void **results = (void **) &ents;
569 unsigned int nents, i;
570 unsigned long flags;
571 phys_addr_t cln;
572
573 if (dma_debug_disabled())
574 return;
575
576 if (!page)
577 return;
578
579 cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
580 spin_lock_irqsave(&radix_lock, flags);
581 nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
582 CACHELINES_PER_PAGE);
583 for (i = 0; i < nents; i++) {
584 phys_addr_t ent_cln = to_cacheline_number(ents[i]);
585
586 if (ent_cln == cln) {
587 entry = ents[i];
588 break;
589 } else if (ent_cln >= cln + CACHELINES_PER_PAGE)
590 break;
591 }
592 spin_unlock_irqrestore(&radix_lock, flags);
593
594 if (!entry)
595 return;
596
597 cln = to_cacheline_number(entry);
598 err_printk(entry->dev, entry,
599 "cpu touching an active dma mapped cacheline [cln=%pa]\n",
600 &cln);
601 }
602
603
604
605
606
607 static void add_dma_entry(struct dma_debug_entry *entry)
608 {
609 struct hash_bucket *bucket;
610 unsigned long flags;
611 int rc;
612
613 bucket = get_hash_bucket(entry, &flags);
614 hash_bucket_add(bucket, entry);
615 put_hash_bucket(bucket, &flags);
616
617 rc = active_cacheline_insert(entry);
618 if (rc == -ENOMEM) {
619 pr_err("cacheline tracking ENOMEM, dma-debug disabled\n");
620 global_disable = true;
621 }
622
623
624
625
626 }
627
628 static int dma_debug_create_entries(gfp_t gfp)
629 {
630 struct dma_debug_entry *entry;
631 int i;
632
633 entry = (void *)get_zeroed_page(gfp);
634 if (!entry)
635 return -ENOMEM;
636
637 for (i = 0; i < DMA_DEBUG_DYNAMIC_ENTRIES; i++)
638 list_add_tail(&entry[i].list, &free_entries);
639
640 num_free_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
641 nr_total_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
642
643 return 0;
644 }
645
646 static struct dma_debug_entry *__dma_entry_alloc(void)
647 {
648 struct dma_debug_entry *entry;
649
650 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
651 list_del(&entry->list);
652 memset(entry, 0, sizeof(*entry));
653
654 num_free_entries -= 1;
655 if (num_free_entries < min_free_entries)
656 min_free_entries = num_free_entries;
657
658 return entry;
659 }
660
661 void __dma_entry_alloc_check_leak(void)
662 {
663 u32 tmp = nr_total_entries % nr_prealloc_entries;
664
665
666 if (tmp < DMA_DEBUG_DYNAMIC_ENTRIES) {
667 pr_info("dma_debug_entry pool grown to %u (%u00%%)\n",
668 nr_total_entries,
669 (nr_total_entries / nr_prealloc_entries));
670 }
671 }
672
673
674
675
676
677
678 static struct dma_debug_entry *dma_entry_alloc(void)
679 {
680 struct dma_debug_entry *entry;
681 unsigned long flags;
682
683 spin_lock_irqsave(&free_entries_lock, flags);
684 if (num_free_entries == 0) {
685 if (dma_debug_create_entries(GFP_ATOMIC)) {
686 global_disable = true;
687 spin_unlock_irqrestore(&free_entries_lock, flags);
688 pr_err("debugging out of memory - disabling\n");
689 return NULL;
690 }
691 __dma_entry_alloc_check_leak();
692 }
693
694 entry = __dma_entry_alloc();
695
696 spin_unlock_irqrestore(&free_entries_lock, flags);
697
698 #ifdef CONFIG_STACKTRACE
699 entry->stack_len = stack_trace_save(entry->stack_entries,
700 ARRAY_SIZE(entry->stack_entries),
701 1);
702 #endif
703 return entry;
704 }
705
706 static void dma_entry_free(struct dma_debug_entry *entry)
707 {
708 unsigned long flags;
709
710 active_cacheline_remove(entry);
711
712
713
714
715
716 spin_lock_irqsave(&free_entries_lock, flags);
717 list_add(&entry->list, &free_entries);
718 num_free_entries += 1;
719 spin_unlock_irqrestore(&free_entries_lock, flags);
720 }
721
722
723
724
725
726
727
728
729
730 static ssize_t filter_read(struct file *file, char __user *user_buf,
731 size_t count, loff_t *ppos)
732 {
733 char buf[NAME_MAX_LEN + 1];
734 unsigned long flags;
735 int len;
736
737 if (!current_driver_name[0])
738 return 0;
739
740
741
742
743
744
745 read_lock_irqsave(&driver_name_lock, flags);
746 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
747 read_unlock_irqrestore(&driver_name_lock, flags);
748
749 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
750 }
751
752 static ssize_t filter_write(struct file *file, const char __user *userbuf,
753 size_t count, loff_t *ppos)
754 {
755 char buf[NAME_MAX_LEN];
756 unsigned long flags;
757 size_t len;
758 int i;
759
760
761
762
763
764
765
766 len = min(count, (size_t)(NAME_MAX_LEN - 1));
767 if (copy_from_user(buf, userbuf, len))
768 return -EFAULT;
769
770 buf[len] = 0;
771
772 write_lock_irqsave(&driver_name_lock, flags);
773
774
775
776
777
778
779
780
781
782 if (!isalnum(buf[0])) {
783
784
785
786
787
788 if (current_driver_name[0])
789 pr_info("switching off dma-debug driver filter\n");
790 current_driver_name[0] = 0;
791 current_driver = NULL;
792 goto out_unlock;
793 }
794
795
796
797
798
799 for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
800 current_driver_name[i] = buf[i];
801 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
802 break;
803 }
804 current_driver_name[i] = 0;
805 current_driver = NULL;
806
807 pr_info("enable driver filter for driver [%s]\n",
808 current_driver_name);
809
810 out_unlock:
811 write_unlock_irqrestore(&driver_name_lock, flags);
812
813 return count;
814 }
815
816 static const struct file_operations filter_fops = {
817 .read = filter_read,
818 .write = filter_write,
819 .llseek = default_llseek,
820 };
821
822 static int dump_show(struct seq_file *seq, void *v)
823 {
824 int idx;
825
826 for (idx = 0; idx < HASH_SIZE; idx++) {
827 struct hash_bucket *bucket = &dma_entry_hash[idx];
828 struct dma_debug_entry *entry;
829 unsigned long flags;
830
831 spin_lock_irqsave(&bucket->lock, flags);
832 list_for_each_entry(entry, &bucket->list, list) {
833 seq_printf(seq,
834 "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n",
835 dev_name(entry->dev),
836 dev_driver_string(entry->dev),
837 type2name[entry->type], idx,
838 phys_addr(entry), entry->pfn,
839 entry->dev_addr, entry->size,
840 dir2name[entry->direction],
841 maperr2str[entry->map_err_type]);
842 }
843 spin_unlock_irqrestore(&bucket->lock, flags);
844 }
845 return 0;
846 }
847 DEFINE_SHOW_ATTRIBUTE(dump);
848
849 static void dma_debug_fs_init(void)
850 {
851 struct dentry *dentry = debugfs_create_dir("dma-api", NULL);
852
853 debugfs_create_bool("disabled", 0444, dentry, &global_disable);
854 debugfs_create_u32("error_count", 0444, dentry, &error_count);
855 debugfs_create_u32("all_errors", 0644, dentry, &show_all_errors);
856 debugfs_create_u32("num_errors", 0644, dentry, &show_num_errors);
857 debugfs_create_u32("num_free_entries", 0444, dentry, &num_free_entries);
858 debugfs_create_u32("min_free_entries", 0444, dentry, &min_free_entries);
859 debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries);
860 debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops);
861 debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops);
862 }
863
864 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
865 {
866 struct dma_debug_entry *entry;
867 unsigned long flags;
868 int count = 0, i;
869
870 for (i = 0; i < HASH_SIZE; ++i) {
871 spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
872 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
873 if (entry->dev == dev) {
874 count += 1;
875 *out_entry = entry;
876 }
877 }
878 spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
879 }
880
881 return count;
882 }
883
884 static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
885 {
886 struct device *dev = data;
887 struct dma_debug_entry *uninitialized_var(entry);
888 int count;
889
890 if (dma_debug_disabled())
891 return 0;
892
893 switch (action) {
894 case BUS_NOTIFY_UNBOUND_DRIVER:
895 count = device_dma_allocations(dev, &entry);
896 if (count == 0)
897 break;
898 err_printk(dev, entry, "device driver has pending "
899 "DMA allocations while released from device "
900 "[count=%d]\n"
901 "One of leaked entries details: "
902 "[device address=0x%016llx] [size=%llu bytes] "
903 "[mapped with %s] [mapped as %s]\n",
904 count, entry->dev_addr, entry->size,
905 dir2name[entry->direction], type2name[entry->type]);
906 break;
907 default:
908 break;
909 }
910
911 return 0;
912 }
913
914 void dma_debug_add_bus(struct bus_type *bus)
915 {
916 struct notifier_block *nb;
917
918 if (dma_debug_disabled())
919 return;
920
921 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
922 if (nb == NULL) {
923 pr_err("dma_debug_add_bus: out of memory\n");
924 return;
925 }
926
927 nb->notifier_call = dma_debug_device_change;
928
929 bus_register_notifier(bus, nb);
930 }
931
932 static int dma_debug_init(void)
933 {
934 int i, nr_pages;
935
936
937
938
939 if (global_disable)
940 return 0;
941
942 for (i = 0; i < HASH_SIZE; ++i) {
943 INIT_LIST_HEAD(&dma_entry_hash[i].list);
944 spin_lock_init(&dma_entry_hash[i].lock);
945 }
946
947 dma_debug_fs_init();
948
949 nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES);
950 for (i = 0; i < nr_pages; ++i)
951 dma_debug_create_entries(GFP_KERNEL);
952 if (num_free_entries >= nr_prealloc_entries) {
953 pr_info("preallocated %d debug entries\n", nr_total_entries);
954 } else if (num_free_entries > 0) {
955 pr_warn("%d debug entries requested but only %d allocated\n",
956 nr_prealloc_entries, nr_total_entries);
957 } else {
958 pr_err("debugging out of memory error - disabled\n");
959 global_disable = true;
960
961 return 0;
962 }
963 min_free_entries = num_free_entries;
964
965 dma_debug_initialized = true;
966
967 pr_info("debugging enabled by kernel config\n");
968 return 0;
969 }
970 core_initcall(dma_debug_init);
971
972 static __init int dma_debug_cmdline(char *str)
973 {
974 if (!str)
975 return -EINVAL;
976
977 if (strncmp(str, "off", 3) == 0) {
978 pr_info("debugging disabled on kernel command line\n");
979 global_disable = true;
980 }
981
982 return 0;
983 }
984
985 static __init int dma_debug_entries_cmdline(char *str)
986 {
987 if (!str)
988 return -EINVAL;
989 if (!get_option(&str, &nr_prealloc_entries))
990 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
991 return 0;
992 }
993
994 __setup("dma_debug=", dma_debug_cmdline);
995 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
996
997 static void check_unmap(struct dma_debug_entry *ref)
998 {
999 struct dma_debug_entry *entry;
1000 struct hash_bucket *bucket;
1001 unsigned long flags;
1002
1003 bucket = get_hash_bucket(ref, &flags);
1004 entry = bucket_find_exact(bucket, ref);
1005
1006 if (!entry) {
1007
1008 put_hash_bucket(bucket, &flags);
1009
1010 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
1011 err_printk(ref->dev, NULL,
1012 "device driver tries to free an "
1013 "invalid DMA memory address\n");
1014 } else {
1015 err_printk(ref->dev, NULL,
1016 "device driver tries to free DMA "
1017 "memory it has not allocated [device "
1018 "address=0x%016llx] [size=%llu bytes]\n",
1019 ref->dev_addr, ref->size);
1020 }
1021 return;
1022 }
1023
1024 if (ref->size != entry->size) {
1025 err_printk(ref->dev, entry, "device driver frees "
1026 "DMA memory with different size "
1027 "[device address=0x%016llx] [map size=%llu bytes] "
1028 "[unmap size=%llu bytes]\n",
1029 ref->dev_addr, entry->size, ref->size);
1030 }
1031
1032 if (ref->type != entry->type) {
1033 err_printk(ref->dev, entry, "device driver frees "
1034 "DMA memory with wrong function "
1035 "[device address=0x%016llx] [size=%llu bytes] "
1036 "[mapped as %s] [unmapped as %s]\n",
1037 ref->dev_addr, ref->size,
1038 type2name[entry->type], type2name[ref->type]);
1039 } else if ((entry->type == dma_debug_coherent) &&
1040 (phys_addr(ref) != phys_addr(entry))) {
1041 err_printk(ref->dev, entry, "device driver frees "
1042 "DMA memory with different CPU address "
1043 "[device address=0x%016llx] [size=%llu bytes] "
1044 "[cpu alloc address=0x%016llx] "
1045 "[cpu free address=0x%016llx]",
1046 ref->dev_addr, ref->size,
1047 phys_addr(entry),
1048 phys_addr(ref));
1049 }
1050
1051 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1052 ref->sg_call_ents != entry->sg_call_ents) {
1053 err_printk(ref->dev, entry, "device driver frees "
1054 "DMA sg list with different entry count "
1055 "[map count=%d] [unmap count=%d]\n",
1056 entry->sg_call_ents, ref->sg_call_ents);
1057 }
1058
1059
1060
1061
1062
1063 if (ref->direction != entry->direction) {
1064 err_printk(ref->dev, entry, "device driver frees "
1065 "DMA memory with different direction "
1066 "[device address=0x%016llx] [size=%llu bytes] "
1067 "[mapped with %s] [unmapped with %s]\n",
1068 ref->dev_addr, ref->size,
1069 dir2name[entry->direction],
1070 dir2name[ref->direction]);
1071 }
1072
1073
1074
1075
1076
1077
1078 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1079 err_printk(ref->dev, entry,
1080 "device driver failed to check map error"
1081 "[device address=0x%016llx] [size=%llu bytes] "
1082 "[mapped as %s]",
1083 ref->dev_addr, ref->size,
1084 type2name[entry->type]);
1085 }
1086
1087 hash_bucket_del(entry);
1088 dma_entry_free(entry);
1089
1090 put_hash_bucket(bucket, &flags);
1091 }
1092
1093 static void check_for_stack(struct device *dev,
1094 struct page *page, size_t offset)
1095 {
1096 void *addr;
1097 struct vm_struct *stack_vm_area = task_stack_vm_area(current);
1098
1099 if (!stack_vm_area) {
1100
1101 if (PageHighMem(page))
1102 return;
1103 addr = page_address(page) + offset;
1104 if (object_is_on_stack(addr))
1105 err_printk(dev, NULL, "device driver maps memory from stack [addr=%p]\n", addr);
1106 } else {
1107
1108 int i;
1109
1110 for (i = 0; i < stack_vm_area->nr_pages; i++) {
1111 if (page != stack_vm_area->pages[i])
1112 continue;
1113
1114 addr = (u8 *)current->stack + i * PAGE_SIZE + offset;
1115 err_printk(dev, NULL, "device driver maps memory from stack [probable addr=%p]\n", addr);
1116 break;
1117 }
1118 }
1119 }
1120
1121 static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
1122 {
1123 unsigned long a1 = (unsigned long)addr;
1124 unsigned long b1 = a1 + len;
1125 unsigned long a2 = (unsigned long)start;
1126 unsigned long b2 = (unsigned long)end;
1127
1128 return !(b1 <= a2 || a1 >= b2);
1129 }
1130
1131 static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1132 {
1133 if (overlap(addr, len, _stext, _etext) ||
1134 overlap(addr, len, __start_rodata, __end_rodata))
1135 err_printk(dev, NULL, "device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1136 }
1137
1138 static void check_sync(struct device *dev,
1139 struct dma_debug_entry *ref,
1140 bool to_cpu)
1141 {
1142 struct dma_debug_entry *entry;
1143 struct hash_bucket *bucket;
1144 unsigned long flags;
1145
1146 bucket = get_hash_bucket(ref, &flags);
1147
1148 entry = bucket_find_contain(&bucket, ref, &flags);
1149
1150 if (!entry) {
1151 err_printk(dev, NULL, "device driver tries "
1152 "to sync DMA memory it has not allocated "
1153 "[device address=0x%016llx] [size=%llu bytes]\n",
1154 (unsigned long long)ref->dev_addr, ref->size);
1155 goto out;
1156 }
1157
1158 if (ref->size > entry->size) {
1159 err_printk(dev, entry, "device driver syncs"
1160 " DMA memory outside allocated range "
1161 "[device address=0x%016llx] "
1162 "[allocation size=%llu bytes] "
1163 "[sync offset+size=%llu]\n",
1164 entry->dev_addr, entry->size,
1165 ref->size);
1166 }
1167
1168 if (entry->direction == DMA_BIDIRECTIONAL)
1169 goto out;
1170
1171 if (ref->direction != entry->direction) {
1172 err_printk(dev, entry, "device driver syncs "
1173 "DMA memory with different direction "
1174 "[device address=0x%016llx] [size=%llu bytes] "
1175 "[mapped with %s] [synced with %s]\n",
1176 (unsigned long long)ref->dev_addr, entry->size,
1177 dir2name[entry->direction],
1178 dir2name[ref->direction]);
1179 }
1180
1181 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1182 !(ref->direction == DMA_TO_DEVICE))
1183 err_printk(dev, entry, "device driver syncs "
1184 "device read-only DMA memory for cpu "
1185 "[device address=0x%016llx] [size=%llu bytes] "
1186 "[mapped with %s] [synced with %s]\n",
1187 (unsigned long long)ref->dev_addr, entry->size,
1188 dir2name[entry->direction],
1189 dir2name[ref->direction]);
1190
1191 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1192 !(ref->direction == DMA_FROM_DEVICE))
1193 err_printk(dev, entry, "device driver syncs "
1194 "device write-only DMA memory to device "
1195 "[device address=0x%016llx] [size=%llu bytes] "
1196 "[mapped with %s] [synced with %s]\n",
1197 (unsigned long long)ref->dev_addr, entry->size,
1198 dir2name[entry->direction],
1199 dir2name[ref->direction]);
1200
1201 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1202 ref->sg_call_ents != entry->sg_call_ents) {
1203 err_printk(ref->dev, entry, "device driver syncs "
1204 "DMA sg list with different entry count "
1205 "[map count=%d] [sync count=%d]\n",
1206 entry->sg_call_ents, ref->sg_call_ents);
1207 }
1208
1209 out:
1210 put_hash_bucket(bucket, &flags);
1211 }
1212
1213 static void check_sg_segment(struct device *dev, struct scatterlist *sg)
1214 {
1215 #ifdef CONFIG_DMA_API_DEBUG_SG
1216 unsigned int max_seg = dma_get_max_seg_size(dev);
1217 u64 start, end, boundary = dma_get_seg_boundary(dev);
1218
1219
1220
1221
1222
1223 if (sg->length > max_seg)
1224 err_printk(dev, NULL, "mapping sg segment longer than device claims to support [len=%u] [max=%u]\n",
1225 sg->length, max_seg);
1226
1227
1228
1229
1230
1231 start = sg_dma_address(sg);
1232 end = start + sg_dma_len(sg) - 1;
1233 if ((start ^ end) & ~boundary)
1234 err_printk(dev, NULL, "mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n",
1235 start, end, boundary);
1236 #endif
1237 }
1238
1239 void debug_dma_map_single(struct device *dev, const void *addr,
1240 unsigned long len)
1241 {
1242 if (unlikely(dma_debug_disabled()))
1243 return;
1244
1245 if (!virt_addr_valid(addr))
1246 err_printk(dev, NULL, "device driver maps memory from invalid area [addr=%p] [len=%lu]\n",
1247 addr, len);
1248
1249 if (is_vmalloc_addr(addr))
1250 err_printk(dev, NULL, "device driver maps memory from vmalloc area [addr=%p] [len=%lu]\n",
1251 addr, len);
1252 }
1253 EXPORT_SYMBOL(debug_dma_map_single);
1254
1255 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1256 size_t size, int direction, dma_addr_t dma_addr)
1257 {
1258 struct dma_debug_entry *entry;
1259
1260 if (unlikely(dma_debug_disabled()))
1261 return;
1262
1263 if (dma_mapping_error(dev, dma_addr))
1264 return;
1265
1266 entry = dma_entry_alloc();
1267 if (!entry)
1268 return;
1269
1270 entry->dev = dev;
1271 entry->type = dma_debug_single;
1272 entry->pfn = page_to_pfn(page);
1273 entry->offset = offset,
1274 entry->dev_addr = dma_addr;
1275 entry->size = size;
1276 entry->direction = direction;
1277 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1278
1279 check_for_stack(dev, page, offset);
1280
1281 if (!PageHighMem(page)) {
1282 void *addr = page_address(page) + offset;
1283
1284 check_for_illegal_area(dev, addr, size);
1285 }
1286
1287 add_dma_entry(entry);
1288 }
1289 EXPORT_SYMBOL(debug_dma_map_page);
1290
1291 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1292 {
1293 struct dma_debug_entry ref;
1294 struct dma_debug_entry *entry;
1295 struct hash_bucket *bucket;
1296 unsigned long flags;
1297
1298 if (unlikely(dma_debug_disabled()))
1299 return;
1300
1301 ref.dev = dev;
1302 ref.dev_addr = dma_addr;
1303 bucket = get_hash_bucket(&ref, &flags);
1304
1305 list_for_each_entry(entry, &bucket->list, list) {
1306 if (!exact_match(&ref, entry))
1307 continue;
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1320 entry->map_err_type = MAP_ERR_CHECKED;
1321 break;
1322 }
1323 }
1324
1325 put_hash_bucket(bucket, &flags);
1326 }
1327 EXPORT_SYMBOL(debug_dma_mapping_error);
1328
1329 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1330 size_t size, int direction)
1331 {
1332 struct dma_debug_entry ref = {
1333 .type = dma_debug_single,
1334 .dev = dev,
1335 .dev_addr = addr,
1336 .size = size,
1337 .direction = direction,
1338 };
1339
1340 if (unlikely(dma_debug_disabled()))
1341 return;
1342 check_unmap(&ref);
1343 }
1344 EXPORT_SYMBOL(debug_dma_unmap_page);
1345
1346 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1347 int nents, int mapped_ents, int direction)
1348 {
1349 struct dma_debug_entry *entry;
1350 struct scatterlist *s;
1351 int i;
1352
1353 if (unlikely(dma_debug_disabled()))
1354 return;
1355
1356 for_each_sg(sg, s, mapped_ents, i) {
1357 entry = dma_entry_alloc();
1358 if (!entry)
1359 return;
1360
1361 entry->type = dma_debug_sg;
1362 entry->dev = dev;
1363 entry->pfn = page_to_pfn(sg_page(s));
1364 entry->offset = s->offset,
1365 entry->size = sg_dma_len(s);
1366 entry->dev_addr = sg_dma_address(s);
1367 entry->direction = direction;
1368 entry->sg_call_ents = nents;
1369 entry->sg_mapped_ents = mapped_ents;
1370
1371 check_for_stack(dev, sg_page(s), s->offset);
1372
1373 if (!PageHighMem(sg_page(s))) {
1374 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1375 }
1376
1377 check_sg_segment(dev, s);
1378
1379 add_dma_entry(entry);
1380 }
1381 }
1382 EXPORT_SYMBOL(debug_dma_map_sg);
1383
1384 static int get_nr_mapped_entries(struct device *dev,
1385 struct dma_debug_entry *ref)
1386 {
1387 struct dma_debug_entry *entry;
1388 struct hash_bucket *bucket;
1389 unsigned long flags;
1390 int mapped_ents;
1391
1392 bucket = get_hash_bucket(ref, &flags);
1393 entry = bucket_find_exact(bucket, ref);
1394 mapped_ents = 0;
1395
1396 if (entry)
1397 mapped_ents = entry->sg_mapped_ents;
1398 put_hash_bucket(bucket, &flags);
1399
1400 return mapped_ents;
1401 }
1402
1403 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1404 int nelems, int dir)
1405 {
1406 struct scatterlist *s;
1407 int mapped_ents = 0, i;
1408
1409 if (unlikely(dma_debug_disabled()))
1410 return;
1411
1412 for_each_sg(sglist, s, nelems, i) {
1413
1414 struct dma_debug_entry ref = {
1415 .type = dma_debug_sg,
1416 .dev = dev,
1417 .pfn = page_to_pfn(sg_page(s)),
1418 .offset = s->offset,
1419 .dev_addr = sg_dma_address(s),
1420 .size = sg_dma_len(s),
1421 .direction = dir,
1422 .sg_call_ents = nelems,
1423 };
1424
1425 if (mapped_ents && i >= mapped_ents)
1426 break;
1427
1428 if (!i)
1429 mapped_ents = get_nr_mapped_entries(dev, &ref);
1430
1431 check_unmap(&ref);
1432 }
1433 }
1434 EXPORT_SYMBOL(debug_dma_unmap_sg);
1435
1436 void debug_dma_alloc_coherent(struct device *dev, size_t size,
1437 dma_addr_t dma_addr, void *virt)
1438 {
1439 struct dma_debug_entry *entry;
1440
1441 if (unlikely(dma_debug_disabled()))
1442 return;
1443
1444 if (unlikely(virt == NULL))
1445 return;
1446
1447
1448 if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
1449 return;
1450
1451 entry = dma_entry_alloc();
1452 if (!entry)
1453 return;
1454
1455 entry->type = dma_debug_coherent;
1456 entry->dev = dev;
1457 entry->offset = offset_in_page(virt);
1458 entry->size = size;
1459 entry->dev_addr = dma_addr;
1460 entry->direction = DMA_BIDIRECTIONAL;
1461
1462 if (is_vmalloc_addr(virt))
1463 entry->pfn = vmalloc_to_pfn(virt);
1464 else
1465 entry->pfn = page_to_pfn(virt_to_page(virt));
1466
1467 add_dma_entry(entry);
1468 }
1469
1470 void debug_dma_free_coherent(struct device *dev, size_t size,
1471 void *virt, dma_addr_t addr)
1472 {
1473 struct dma_debug_entry ref = {
1474 .type = dma_debug_coherent,
1475 .dev = dev,
1476 .offset = offset_in_page(virt),
1477 .dev_addr = addr,
1478 .size = size,
1479 .direction = DMA_BIDIRECTIONAL,
1480 };
1481
1482
1483 if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
1484 return;
1485
1486 if (is_vmalloc_addr(virt))
1487 ref.pfn = vmalloc_to_pfn(virt);
1488 else
1489 ref.pfn = page_to_pfn(virt_to_page(virt));
1490
1491 if (unlikely(dma_debug_disabled()))
1492 return;
1493
1494 check_unmap(&ref);
1495 }
1496
1497 void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
1498 int direction, dma_addr_t dma_addr)
1499 {
1500 struct dma_debug_entry *entry;
1501
1502 if (unlikely(dma_debug_disabled()))
1503 return;
1504
1505 entry = dma_entry_alloc();
1506 if (!entry)
1507 return;
1508
1509 entry->type = dma_debug_resource;
1510 entry->dev = dev;
1511 entry->pfn = PHYS_PFN(addr);
1512 entry->offset = offset_in_page(addr);
1513 entry->size = size;
1514 entry->dev_addr = dma_addr;
1515 entry->direction = direction;
1516 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1517
1518 add_dma_entry(entry);
1519 }
1520 EXPORT_SYMBOL(debug_dma_map_resource);
1521
1522 void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
1523 size_t size, int direction)
1524 {
1525 struct dma_debug_entry ref = {
1526 .type = dma_debug_resource,
1527 .dev = dev,
1528 .dev_addr = dma_addr,
1529 .size = size,
1530 .direction = direction,
1531 };
1532
1533 if (unlikely(dma_debug_disabled()))
1534 return;
1535
1536 check_unmap(&ref);
1537 }
1538 EXPORT_SYMBOL(debug_dma_unmap_resource);
1539
1540 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1541 size_t size, int direction)
1542 {
1543 struct dma_debug_entry ref;
1544
1545 if (unlikely(dma_debug_disabled()))
1546 return;
1547
1548 ref.type = dma_debug_single;
1549 ref.dev = dev;
1550 ref.dev_addr = dma_handle;
1551 ref.size = size;
1552 ref.direction = direction;
1553 ref.sg_call_ents = 0;
1554
1555 check_sync(dev, &ref, true);
1556 }
1557 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1558
1559 void debug_dma_sync_single_for_device(struct device *dev,
1560 dma_addr_t dma_handle, size_t size,
1561 int direction)
1562 {
1563 struct dma_debug_entry ref;
1564
1565 if (unlikely(dma_debug_disabled()))
1566 return;
1567
1568 ref.type = dma_debug_single;
1569 ref.dev = dev;
1570 ref.dev_addr = dma_handle;
1571 ref.size = size;
1572 ref.direction = direction;
1573 ref.sg_call_ents = 0;
1574
1575 check_sync(dev, &ref, false);
1576 }
1577 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1578
1579 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1580 int nelems, int direction)
1581 {
1582 struct scatterlist *s;
1583 int mapped_ents = 0, i;
1584
1585 if (unlikely(dma_debug_disabled()))
1586 return;
1587
1588 for_each_sg(sg, s, nelems, i) {
1589
1590 struct dma_debug_entry ref = {
1591 .type = dma_debug_sg,
1592 .dev = dev,
1593 .pfn = page_to_pfn(sg_page(s)),
1594 .offset = s->offset,
1595 .dev_addr = sg_dma_address(s),
1596 .size = sg_dma_len(s),
1597 .direction = direction,
1598 .sg_call_ents = nelems,
1599 };
1600
1601 if (!i)
1602 mapped_ents = get_nr_mapped_entries(dev, &ref);
1603
1604 if (i >= mapped_ents)
1605 break;
1606
1607 check_sync(dev, &ref, true);
1608 }
1609 }
1610 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1611
1612 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1613 int nelems, int direction)
1614 {
1615 struct scatterlist *s;
1616 int mapped_ents = 0, i;
1617
1618 if (unlikely(dma_debug_disabled()))
1619 return;
1620
1621 for_each_sg(sg, s, nelems, i) {
1622
1623 struct dma_debug_entry ref = {
1624 .type = dma_debug_sg,
1625 .dev = dev,
1626 .pfn = page_to_pfn(sg_page(s)),
1627 .offset = s->offset,
1628 .dev_addr = sg_dma_address(s),
1629 .size = sg_dma_len(s),
1630 .direction = direction,
1631 .sg_call_ents = nelems,
1632 };
1633 if (!i)
1634 mapped_ents = get_nr_mapped_entries(dev, &ref);
1635
1636 if (i >= mapped_ents)
1637 break;
1638
1639 check_sync(dev, &ref, false);
1640 }
1641 }
1642 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1643
1644 static int __init dma_debug_driver_setup(char *str)
1645 {
1646 int i;
1647
1648 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1649 current_driver_name[i] = *str;
1650 if (*str == 0)
1651 break;
1652 }
1653
1654 if (current_driver_name[0])
1655 pr_info("enable driver filter for driver [%s]\n",
1656 current_driver_name);
1657
1658
1659 return 1;
1660 }
1661 __setup("dma_debug_driver=", dma_debug_driver_setup);