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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
41enum {
42 dma_debug_single,
43 dma_debug_page,
44 dma_debug_sg,
45 dma_debug_coherent,
46};
47
48enum 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
58
59
60
61
62
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64
65
66
67
68
69
70struct 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
88typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
89
90struct hash_bucket {
91 struct list_head list;
92 spinlock_t lock;
93} ____cacheline_aligned_in_smp;
94
95
96static struct hash_bucket dma_entry_hash[HASH_SIZE];
97
98static LIST_HEAD(free_entries);
99
100static DEFINE_SPINLOCK(free_entries_lock);
101
102
103static bool global_disable __read_mostly;
104
105
106static bool dma_debug_initialized __read_mostly;
107
108static inline bool dma_debug_disabled(void)
109{
110 return global_disable || !dma_debug_initialized;
111}
112
113
114static u32 error_count;
115
116
117static u32 show_all_errors __read_mostly;
118
119static u32 show_num_errors = 1;
120
121static u32 num_free_entries;
122static u32 min_free_entries;
123static u32 nr_total_entries;
124
125
126static u32 req_entries;
127
128
129static struct dentry *dma_debug_dent __read_mostly;
130static struct dentry *global_disable_dent __read_mostly;
131static struct dentry *error_count_dent __read_mostly;
132static struct dentry *show_all_errors_dent __read_mostly;
133static struct dentry *show_num_errors_dent __read_mostly;
134static struct dentry *num_free_entries_dent __read_mostly;
135static struct dentry *min_free_entries_dent __read_mostly;
136static struct dentry *filter_dent __read_mostly;
137
138
139
140#define NAME_MAX_LEN 64
141
142static char current_driver_name[NAME_MAX_LEN] __read_mostly;
143static struct device_driver *current_driver __read_mostly;
144
145static DEFINE_RWLOCK(driver_name_lock);
146
147static 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
153static const char *type2name[4] = { "single", "page",
154 "scather-gather", "coherent" };
155
156static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
157 "DMA_FROM_DEVICE", "DMA_NONE" };
158
159
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169
170
171
172static 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
182static bool driver_filter(struct device *dev)
183{
184 struct device_driver *drv;
185 unsigned long flags;
186 bool ret;
187
188
189 if (likely(!current_driver_name[0]))
190 return true;
191
192
193 if (current_driver && dev && dev->driver == current_driver)
194 return true;
195
196
197 if (!dev)
198 return false;
199
200 if (current_driver || !current_driver_name[0])
201 return false;
202
203
204 drv = dev->driver;
205 if (!drv)
206 return false;
207
208
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
238
239
240
241
242static int hash_fn(struct dma_debug_entry *entry)
243{
244
245
246
247
248 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
249}
250
251
252
253
254static 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
267
268static 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
276static 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
282static 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
297
298static 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
311
312
313
314
315
316
317
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
328 return entry;
329 } else if (match_lvl > last_lvl) {
330
331
332
333
334 last_lvl = match_lvl;
335 ret = entry;
336 }
337 }
338
339
340
341
342
343 ret = (matches == 1) ? ret : NULL;
344
345 return ret;
346}
347
348static 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
354static 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
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
383
384static 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
392
393static void hash_bucket_del(struct dma_debug_entry *entry)
394{
395 list_del(&entry->list);
396}
397
398static 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
405
406void 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}
432EXPORT_SYMBOL(debug_dma_dump_mappings);
433
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454
455
456
457static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
458static 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
463static 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
469static 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
479static 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
495static 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
502
503
504
505
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
512static 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
519static 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
526
527
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
541static 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
547 if (entry->direction == DMA_TO_DEVICE)
548 return;
549
550 spin_lock_irqsave(&radix_lock, flags);
551
552
553
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
562
563
564
565
566
567
568void 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
609
610
611static 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
628
629
630}
631
632static 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
648
649
650
651
652static 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
680static void dma_entry_free(struct dma_debug_entry *entry)
681{
682 unsigned long flags;
683
684 active_cacheline_remove(entry);
685
686
687
688
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
696int 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}
741EXPORT_SYMBOL(dma_debug_resize_entries);
742
743
744
745
746
747
748
749
750
751static 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
771out_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
781static 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
793
794
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
803static 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
813
814
815
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
827
828
829
830
831
832
833 if (!isalnum(buf[0])) {
834
835
836
837
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
848
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
861out_unlock:
862 write_unlock_irqrestore(&driver_name_lock, flags);
863
864 return count;
865}
866
867static const struct file_operations filter_fops = {
868 .read = filter_read,
869 .write = filter_write,
870 .llseek = default_llseek,
871};
872
873static 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
923out_err:
924 debugfs_remove_recursive(dma_debug_dent);
925
926 return -ENOMEM;
927}
928
929static 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
953static 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
983void 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
1003
1004void dma_debug_init(u32 num_entries)
1005{
1006 int i;
1007
1008
1009
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
1043static __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
1056static __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
1074static 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
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
1138
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
1165static 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
1172static 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
1182static 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
1189static 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
1260out:
1261 put_hash_bucket(bucket, &flags);
1262}
1263
1264void 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}
1301EXPORT_SYMBOL(debug_dma_map_page);
1302
1303void 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
1323
1324
1325
1326
1327
1328
1329
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}
1339EXPORT_SYMBOL(debug_dma_mapping_error);
1340
1341void 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}
1360EXPORT_SYMBOL(debug_dma_unmap_page);
1361
1362void 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}
1395EXPORT_SYMBOL(debug_dma_map_sg);
1396
1397static 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
1416void 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}
1447EXPORT_SYMBOL(debug_dma_unmap_sg);
1448
1449void 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}
1474EXPORT_SYMBOL(debug_dma_alloc_coherent);
1475
1476void 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}
1494EXPORT_SYMBOL(debug_dma_free_coherent);
1495
1496void 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}
1513EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1514
1515void 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}
1533EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1534
1535void 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}
1554EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1555
1556void 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}
1575EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1576
1577void 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}
1608EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1609
1610void 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}
1640EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1641
1642static 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);
1660