dma-debug: add checks for kernel text and rodata
[linux-3.10.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/device.h>
27 #include <linux/types.h>
28 #include <linux/sched.h>
29 #include <linux/list.h>
30 #include <linux/slab.h>
31
32 #include <asm/sections.h>
33
34 #define HASH_SIZE       1024ULL
35 #define HASH_FN_SHIFT   13
36 #define HASH_FN_MASK    (HASH_SIZE - 1)
37
38 enum {
39         dma_debug_single,
40         dma_debug_page,
41         dma_debug_sg,
42         dma_debug_coherent,
43 };
44
45 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
46
47 struct dma_debug_entry {
48         struct list_head list;
49         struct device    *dev;
50         int              type;
51         phys_addr_t      paddr;
52         u64              dev_addr;
53         u64              size;
54         int              direction;
55         int              sg_call_ents;
56         int              sg_mapped_ents;
57 #ifdef CONFIG_STACKTRACE
58         struct           stack_trace stacktrace;
59         unsigned long    st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
60 #endif
61 };
62
63 struct hash_bucket {
64         struct list_head list;
65         spinlock_t lock;
66 } ____cacheline_aligned_in_smp;
67
68 /* Hash list to save the allocated dma addresses */
69 static struct hash_bucket dma_entry_hash[HASH_SIZE];
70 /* List of pre-allocated dma_debug_entry's */
71 static LIST_HEAD(free_entries);
72 /* Lock for the list above */
73 static DEFINE_SPINLOCK(free_entries_lock);
74
75 /* Global disable flag - will be set in case of an error */
76 static bool global_disable __read_mostly;
77
78 /* Global error count */
79 static u32 error_count;
80
81 /* Global error show enable*/
82 static u32 show_all_errors __read_mostly;
83 /* Number of errors to show */
84 static u32 show_num_errors = 1;
85
86 static u32 num_free_entries;
87 static u32 min_free_entries;
88
89 /* number of preallocated entries requested by kernel cmdline */
90 static u32 req_entries;
91
92 /* debugfs dentry's for the stuff above */
93 static struct dentry *dma_debug_dent        __read_mostly;
94 static struct dentry *global_disable_dent   __read_mostly;
95 static struct dentry *error_count_dent      __read_mostly;
96 static struct dentry *show_all_errors_dent  __read_mostly;
97 static struct dentry *show_num_errors_dent  __read_mostly;
98 static struct dentry *num_free_entries_dent __read_mostly;
99 static struct dentry *min_free_entries_dent __read_mostly;
100
101 static const char *type2name[4] = { "single", "page",
102                                     "scather-gather", "coherent" };
103
104 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
105                                    "DMA_FROM_DEVICE", "DMA_NONE" };
106
107 /*
108  * The access to some variables in this macro is racy. We can't use atomic_t
109  * here because all these variables are exported to debugfs. Some of them even
110  * writeable. This is also the reason why a lock won't help much. But anyway,
111  * the races are no big deal. Here is why:
112  *
113  *   error_count: the addition is racy, but the worst thing that can happen is
114  *                that we don't count some errors
115  *   show_num_errors: the subtraction is racy. Also no big deal because in
116  *                    worst case this will result in one warning more in the
117  *                    system log than the user configured. This variable is
118  *                    writeable via debugfs.
119  */
120 static inline void dump_entry_trace(struct dma_debug_entry *entry)
121 {
122 #ifdef CONFIG_STACKTRACE
123         if (entry) {
124                 printk(KERN_WARNING "Mapped at:\n");
125                 print_stack_trace(&entry->stacktrace, 0);
126         }
127 #endif
128 }
129
130 #define err_printk(dev, entry, format, arg...) do {             \
131                 error_count += 1;                               \
132                 if (show_all_errors || show_num_errors > 0) {   \
133                         WARN(1, "%s %s: " format,               \
134                              dev_driver_string(dev),            \
135                              dev_name(dev) , ## arg);           \
136                         dump_entry_trace(entry);                \
137                 }                                               \
138                 if (!show_all_errors && show_num_errors > 0)    \
139                         show_num_errors -= 1;                   \
140         } while (0);
141
142 /*
143  * Hash related functions
144  *
145  * Every DMA-API request is saved into a struct dma_debug_entry. To
146  * have quick access to these structs they are stored into a hash.
147  */
148 static int hash_fn(struct dma_debug_entry *entry)
149 {
150         /*
151          * Hash function is based on the dma address.
152          * We use bits 20-27 here as the index into the hash
153          */
154         return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
155 }
156
157 /*
158  * Request exclusive access to a hash bucket for a given dma_debug_entry.
159  */
160 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
161                                            unsigned long *flags)
162 {
163         int idx = hash_fn(entry);
164         unsigned long __flags;
165
166         spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
167         *flags = __flags;
168         return &dma_entry_hash[idx];
169 }
170
171 /*
172  * Give up exclusive access to the hash bucket
173  */
174 static void put_hash_bucket(struct hash_bucket *bucket,
175                             unsigned long *flags)
176 {
177         unsigned long __flags = *flags;
178
179         spin_unlock_irqrestore(&bucket->lock, __flags);
180 }
181
182 /*
183  * Search a given entry in the hash bucket list
184  */
185 static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
186                                                 struct dma_debug_entry *ref)
187 {
188         struct dma_debug_entry *entry;
189
190         list_for_each_entry(entry, &bucket->list, list) {
191                 if ((entry->dev_addr == ref->dev_addr) &&
192                     (entry->dev == ref->dev))
193                         return entry;
194         }
195
196         return NULL;
197 }
198
199 /*
200  * Add an entry to a hash bucket
201  */
202 static void hash_bucket_add(struct hash_bucket *bucket,
203                             struct dma_debug_entry *entry)
204 {
205         list_add_tail(&entry->list, &bucket->list);
206 }
207
208 /*
209  * Remove entry from a hash bucket list
210  */
211 static void hash_bucket_del(struct dma_debug_entry *entry)
212 {
213         list_del(&entry->list);
214 }
215
216 /*
217  * Dump mapping entries for debugging purposes
218  */
219 void debug_dma_dump_mappings(struct device *dev)
220 {
221         int idx;
222
223         for (idx = 0; idx < HASH_SIZE; idx++) {
224                 struct hash_bucket *bucket = &dma_entry_hash[idx];
225                 struct dma_debug_entry *entry;
226                 unsigned long flags;
227
228                 spin_lock_irqsave(&bucket->lock, flags);
229
230                 list_for_each_entry(entry, &bucket->list, list) {
231                         if (!dev || dev == entry->dev) {
232                                 dev_info(entry->dev,
233                                          "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
234                                          type2name[entry->type], idx,
235                                          (unsigned long long)entry->paddr,
236                                          entry->dev_addr, entry->size,
237                                          dir2name[entry->direction]);
238                         }
239                 }
240
241                 spin_unlock_irqrestore(&bucket->lock, flags);
242         }
243 }
244 EXPORT_SYMBOL(debug_dma_dump_mappings);
245
246 /*
247  * Wrapper function for adding an entry to the hash.
248  * This function takes care of locking itself.
249  */
250 static void add_dma_entry(struct dma_debug_entry *entry)
251 {
252         struct hash_bucket *bucket;
253         unsigned long flags;
254
255         bucket = get_hash_bucket(entry, &flags);
256         hash_bucket_add(bucket, entry);
257         put_hash_bucket(bucket, &flags);
258 }
259
260 /* struct dma_entry allocator
261  *
262  * The next two functions implement the allocator for
263  * struct dma_debug_entries.
264  */
265 static struct dma_debug_entry *dma_entry_alloc(void)
266 {
267         struct dma_debug_entry *entry = NULL;
268         unsigned long flags;
269
270         spin_lock_irqsave(&free_entries_lock, flags);
271
272         if (list_empty(&free_entries)) {
273                 printk(KERN_ERR "DMA-API: debugging out of memory "
274                                 "- disabling\n");
275                 global_disable = true;
276                 goto out;
277         }
278
279         entry = list_entry(free_entries.next, struct dma_debug_entry, list);
280         list_del(&entry->list);
281         memset(entry, 0, sizeof(*entry));
282
283 #ifdef CONFIG_STACKTRACE
284         entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
285         entry->stacktrace.entries = entry->st_entries;
286         entry->stacktrace.skip = 2;
287         save_stack_trace(&entry->stacktrace);
288 #endif
289         num_free_entries -= 1;
290         if (num_free_entries < min_free_entries)
291                 min_free_entries = num_free_entries;
292
293 out:
294         spin_unlock_irqrestore(&free_entries_lock, flags);
295
296         return entry;
297 }
298
299 static void dma_entry_free(struct dma_debug_entry *entry)
300 {
301         unsigned long flags;
302
303         /*
304          * add to beginning of the list - this way the entries are
305          * more likely cache hot when they are reallocated.
306          */
307         spin_lock_irqsave(&free_entries_lock, flags);
308         list_add(&entry->list, &free_entries);
309         num_free_entries += 1;
310         spin_unlock_irqrestore(&free_entries_lock, flags);
311 }
312
313 /*
314  * DMA-API debugging init code
315  *
316  * The init code does two things:
317  *   1. Initialize core data structures
318  *   2. Preallocate a given number of dma_debug_entry structs
319  */
320
321 static int prealloc_memory(u32 num_entries)
322 {
323         struct dma_debug_entry *entry, *next_entry;
324         int i;
325
326         for (i = 0; i < num_entries; ++i) {
327                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
328                 if (!entry)
329                         goto out_err;
330
331                 list_add_tail(&entry->list, &free_entries);
332         }
333
334         num_free_entries = num_entries;
335         min_free_entries = num_entries;
336
337         printk(KERN_INFO "DMA-API: preallocated %d debug entries\n",
338                         num_entries);
339
340         return 0;
341
342 out_err:
343
344         list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
345                 list_del(&entry->list);
346                 kfree(entry);
347         }
348
349         return -ENOMEM;
350 }
351
352 static int dma_debug_fs_init(void)
353 {
354         dma_debug_dent = debugfs_create_dir("dma-api", NULL);
355         if (!dma_debug_dent) {
356                 printk(KERN_ERR "DMA-API: can not create debugfs directory\n");
357                 return -ENOMEM;
358         }
359
360         global_disable_dent = debugfs_create_bool("disabled", 0444,
361                         dma_debug_dent,
362                         (u32 *)&global_disable);
363         if (!global_disable_dent)
364                 goto out_err;
365
366         error_count_dent = debugfs_create_u32("error_count", 0444,
367                         dma_debug_dent, &error_count);
368         if (!error_count_dent)
369                 goto out_err;
370
371         show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
372                         dma_debug_dent,
373                         &show_all_errors);
374         if (!show_all_errors_dent)
375                 goto out_err;
376
377         show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
378                         dma_debug_dent,
379                         &show_num_errors);
380         if (!show_num_errors_dent)
381                 goto out_err;
382
383         num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
384                         dma_debug_dent,
385                         &num_free_entries);
386         if (!num_free_entries_dent)
387                 goto out_err;
388
389         min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
390                         dma_debug_dent,
391                         &min_free_entries);
392         if (!min_free_entries_dent)
393                 goto out_err;
394
395         return 0;
396
397 out_err:
398         debugfs_remove_recursive(dma_debug_dent);
399
400         return -ENOMEM;
401 }
402
403
404 /*
405  * Let the architectures decide how many entries should be preallocated.
406  */
407 void dma_debug_init(u32 num_entries)
408 {
409         int i;
410
411         if (global_disable)
412                 return;
413
414         for (i = 0; i < HASH_SIZE; ++i) {
415                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
416                 dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
417         }
418
419         if (dma_debug_fs_init() != 0) {
420                 printk(KERN_ERR "DMA-API: error creating debugfs entries "
421                                 "- disabling\n");
422                 global_disable = true;
423
424                 return;
425         }
426
427         if (req_entries)
428                 num_entries = req_entries;
429
430         if (prealloc_memory(num_entries) != 0) {
431                 printk(KERN_ERR "DMA-API: debugging out of memory error "
432                                 "- disabled\n");
433                 global_disable = true;
434
435                 return;
436         }
437
438         printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
439 }
440
441 static __init int dma_debug_cmdline(char *str)
442 {
443         if (!str)
444                 return -EINVAL;
445
446         if (strncmp(str, "off", 3) == 0) {
447                 printk(KERN_INFO "DMA-API: debugging disabled on kernel "
448                                  "command line\n");
449                 global_disable = true;
450         }
451
452         return 0;
453 }
454
455 static __init int dma_debug_entries_cmdline(char *str)
456 {
457         int res;
458
459         if (!str)
460                 return -EINVAL;
461
462         res = get_option(&str, &req_entries);
463
464         if (!res)
465                 req_entries = 0;
466
467         return 0;
468 }
469
470 __setup("dma_debug=", dma_debug_cmdline);
471 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
472
473 static void check_unmap(struct dma_debug_entry *ref)
474 {
475         struct dma_debug_entry *entry;
476         struct hash_bucket *bucket;
477         unsigned long flags;
478
479         if (dma_mapping_error(ref->dev, ref->dev_addr))
480                 return;
481
482         bucket = get_hash_bucket(ref, &flags);
483         entry = hash_bucket_find(bucket, ref);
484
485         if (!entry) {
486                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
487                            "to free DMA memory it has not allocated "
488                            "[device address=0x%016llx] [size=%llu bytes]\n",
489                            ref->dev_addr, ref->size);
490                 goto out;
491         }
492
493         if (ref->size != entry->size) {
494                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
495                            "DMA memory with different size "
496                            "[device address=0x%016llx] [map size=%llu bytes] "
497                            "[unmap size=%llu bytes]\n",
498                            ref->dev_addr, entry->size, ref->size);
499         }
500
501         if (ref->type != entry->type) {
502                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
503                            "DMA memory with wrong function "
504                            "[device address=0x%016llx] [size=%llu bytes] "
505                            "[mapped as %s] [unmapped as %s]\n",
506                            ref->dev_addr, ref->size,
507                            type2name[entry->type], type2name[ref->type]);
508         } else if ((entry->type == dma_debug_coherent) &&
509                    (ref->paddr != entry->paddr)) {
510                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
511                            "DMA memory with different CPU address "
512                            "[device address=0x%016llx] [size=%llu bytes] "
513                            "[cpu alloc address=%p] [cpu free address=%p]",
514                            ref->dev_addr, ref->size,
515                            (void *)entry->paddr, (void *)ref->paddr);
516         }
517
518         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
519             ref->sg_call_ents != entry->sg_call_ents) {
520                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
521                            "DMA sg list with different entry count "
522                            "[map count=%d] [unmap count=%d]\n",
523                            entry->sg_call_ents, ref->sg_call_ents);
524         }
525
526         /*
527          * This may be no bug in reality - but most implementations of the
528          * DMA API don't handle this properly, so check for it here
529          */
530         if (ref->direction != entry->direction) {
531                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
532                            "DMA memory with different direction "
533                            "[device address=0x%016llx] [size=%llu bytes] "
534                            "[mapped with %s] [unmapped with %s]\n",
535                            ref->dev_addr, ref->size,
536                            dir2name[entry->direction],
537                            dir2name[ref->direction]);
538         }
539
540         hash_bucket_del(entry);
541         dma_entry_free(entry);
542
543 out:
544         put_hash_bucket(bucket, &flags);
545 }
546
547 static void check_for_stack(struct device *dev, void *addr)
548 {
549         if (object_is_on_stack(addr))
550                 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
551                                 "stack [addr=%p]\n", addr);
552 }
553
554 static inline bool overlap(void *addr, u64 size, void *start, void *end)
555 {
556         void *addr2 = (char *)addr + size;
557
558         return ((addr >= start && addr < end) ||
559                 (addr2 >= start && addr2 < end) ||
560                 ((addr < start) && (addr2 >= end)));
561 }
562
563 static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
564 {
565         if (overlap(addr, size, _text, _etext) ||
566             overlap(addr, size, __start_rodata, __end_rodata))
567                 err_printk(dev, NULL, "DMA-API: device driver maps "
568                                 "memory from kernel text or rodata "
569                                 "[addr=%p] [size=%llu]\n", addr, size);
570 }
571
572 static void check_sync(struct device *dev, dma_addr_t addr,
573                        u64 size, u64 offset, int direction, bool to_cpu)
574 {
575         struct dma_debug_entry ref = {
576                 .dev            = dev,
577                 .dev_addr       = addr,
578                 .size           = size,
579                 .direction      = direction,
580         };
581         struct dma_debug_entry *entry;
582         struct hash_bucket *bucket;
583         unsigned long flags;
584
585         bucket = get_hash_bucket(&ref, &flags);
586
587         entry = hash_bucket_find(bucket, &ref);
588
589         if (!entry) {
590                 err_printk(dev, NULL, "DMA-API: device driver tries "
591                                 "to sync DMA memory it has not allocated "
592                                 "[device address=0x%016llx] [size=%llu bytes]\n",
593                                 addr, size);
594                 goto out;
595         }
596
597         if ((offset + size) > entry->size) {
598                 err_printk(dev, entry, "DMA-API: device driver syncs"
599                                 " DMA memory outside allocated range "
600                                 "[device address=0x%016llx] "
601                                 "[allocation size=%llu bytes] [sync offset=%llu] "
602                                 "[sync size=%llu]\n", entry->dev_addr, entry->size,
603                                 offset, size);
604         }
605
606         if (direction != entry->direction) {
607                 err_printk(dev, entry, "DMA-API: device driver syncs "
608                                 "DMA memory with different direction "
609                                 "[device address=0x%016llx] [size=%llu bytes] "
610                                 "[mapped with %s] [synced with %s]\n",
611                                 addr, entry->size,
612                                 dir2name[entry->direction],
613                                 dir2name[direction]);
614         }
615
616         if (entry->direction == DMA_BIDIRECTIONAL)
617                 goto out;
618
619         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
620                       !(direction == DMA_TO_DEVICE))
621                 err_printk(dev, entry, "DMA-API: device driver syncs "
622                                 "device read-only DMA memory for cpu "
623                                 "[device address=0x%016llx] [size=%llu bytes] "
624                                 "[mapped with %s] [synced with %s]\n",
625                                 addr, entry->size,
626                                 dir2name[entry->direction],
627                                 dir2name[direction]);
628
629         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
630                        !(direction == DMA_FROM_DEVICE))
631                 err_printk(dev, entry, "DMA-API: device driver syncs "
632                                 "device write-only DMA memory to device "
633                                 "[device address=0x%016llx] [size=%llu bytes] "
634                                 "[mapped with %s] [synced with %s]\n",
635                                 addr, entry->size,
636                                 dir2name[entry->direction],
637                                 dir2name[direction]);
638
639 out:
640         put_hash_bucket(bucket, &flags);
641
642 }
643
644 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
645                         size_t size, int direction, dma_addr_t dma_addr,
646                         bool map_single)
647 {
648         struct dma_debug_entry *entry;
649
650         if (unlikely(global_disable))
651                 return;
652
653         if (unlikely(dma_mapping_error(dev, dma_addr)))
654                 return;
655
656         entry = dma_entry_alloc();
657         if (!entry)
658                 return;
659
660         entry->dev       = dev;
661         entry->type      = dma_debug_page;
662         entry->paddr     = page_to_phys(page) + offset;
663         entry->dev_addr  = dma_addr;
664         entry->size      = size;
665         entry->direction = direction;
666
667         if (map_single) {
668                 void *addr = ((char *)page_address(page)) + offset;
669
670                 entry->type = dma_debug_single;
671                 check_for_stack(dev, addr);
672                 check_for_illegal_area(dev, addr, size);
673         }
674
675         add_dma_entry(entry);
676 }
677 EXPORT_SYMBOL(debug_dma_map_page);
678
679 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
680                           size_t size, int direction, bool map_single)
681 {
682         struct dma_debug_entry ref = {
683                 .type           = dma_debug_page,
684                 .dev            = dev,
685                 .dev_addr       = addr,
686                 .size           = size,
687                 .direction      = direction,
688         };
689
690         if (unlikely(global_disable))
691                 return;
692
693         if (map_single)
694                 ref.type = dma_debug_single;
695
696         check_unmap(&ref);
697 }
698 EXPORT_SYMBOL(debug_dma_unmap_page);
699
700 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
701                       int nents, int mapped_ents, int direction)
702 {
703         struct dma_debug_entry *entry;
704         struct scatterlist *s;
705         int i;
706
707         if (unlikely(global_disable))
708                 return;
709
710         for_each_sg(sg, s, mapped_ents, i) {
711                 entry = dma_entry_alloc();
712                 if (!entry)
713                         return;
714
715                 entry->type           = dma_debug_sg;
716                 entry->dev            = dev;
717                 entry->paddr          = sg_phys(s);
718                 entry->size           = s->length;
719                 entry->dev_addr       = s->dma_address;
720                 entry->direction      = direction;
721                 entry->sg_call_ents   = nents;
722                 entry->sg_mapped_ents = mapped_ents;
723
724                 check_for_stack(dev, sg_virt(s));
725                 check_for_illegal_area(dev, sg_virt(s), s->length);
726
727                 add_dma_entry(entry);
728         }
729 }
730 EXPORT_SYMBOL(debug_dma_map_sg);
731
732 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
733                         int nelems, int dir)
734 {
735         struct dma_debug_entry *entry;
736         struct scatterlist *s;
737         int mapped_ents = 0, i;
738         unsigned long flags;
739
740         if (unlikely(global_disable))
741                 return;
742
743         for_each_sg(sglist, s, nelems, i) {
744
745                 struct dma_debug_entry ref = {
746                         .type           = dma_debug_sg,
747                         .dev            = dev,
748                         .paddr          = sg_phys(s),
749                         .dev_addr       = s->dma_address,
750                         .size           = s->length,
751                         .direction      = dir,
752                         .sg_call_ents   = 0,
753                 };
754
755                 if (mapped_ents && i >= mapped_ents)
756                         break;
757
758                 if (mapped_ents == 0) {
759                         struct hash_bucket *bucket;
760                         ref.sg_call_ents = nelems;
761                         bucket = get_hash_bucket(&ref, &flags);
762                         entry = hash_bucket_find(bucket, &ref);
763                         if (entry)
764                                 mapped_ents = entry->sg_mapped_ents;
765                         put_hash_bucket(bucket, &flags);
766                 }
767
768                 check_unmap(&ref);
769         }
770 }
771 EXPORT_SYMBOL(debug_dma_unmap_sg);
772
773 void debug_dma_alloc_coherent(struct device *dev, size_t size,
774                               dma_addr_t dma_addr, void *virt)
775 {
776         struct dma_debug_entry *entry;
777
778         if (unlikely(global_disable))
779                 return;
780
781         if (unlikely(virt == NULL))
782                 return;
783
784         entry = dma_entry_alloc();
785         if (!entry)
786                 return;
787
788         entry->type      = dma_debug_coherent;
789         entry->dev       = dev;
790         entry->paddr     = virt_to_phys(virt);
791         entry->size      = size;
792         entry->dev_addr  = dma_addr;
793         entry->direction = DMA_BIDIRECTIONAL;
794
795         add_dma_entry(entry);
796 }
797 EXPORT_SYMBOL(debug_dma_alloc_coherent);
798
799 void debug_dma_free_coherent(struct device *dev, size_t size,
800                          void *virt, dma_addr_t addr)
801 {
802         struct dma_debug_entry ref = {
803                 .type           = dma_debug_coherent,
804                 .dev            = dev,
805                 .paddr          = virt_to_phys(virt),
806                 .dev_addr       = addr,
807                 .size           = size,
808                 .direction      = DMA_BIDIRECTIONAL,
809         };
810
811         if (unlikely(global_disable))
812                 return;
813
814         check_unmap(&ref);
815 }
816 EXPORT_SYMBOL(debug_dma_free_coherent);
817
818 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
819                                    size_t size, int direction)
820 {
821         if (unlikely(global_disable))
822                 return;
823
824         check_sync(dev, dma_handle, size, 0, direction, true);
825 }
826 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
827
828 void debug_dma_sync_single_for_device(struct device *dev,
829                                       dma_addr_t dma_handle, size_t size,
830                                       int direction)
831 {
832         if (unlikely(global_disable))
833                 return;
834
835         check_sync(dev, dma_handle, size, 0, direction, false);
836 }
837 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
838
839 void debug_dma_sync_single_range_for_cpu(struct device *dev,
840                                          dma_addr_t dma_handle,
841                                          unsigned long offset, size_t size,
842                                          int direction)
843 {
844         if (unlikely(global_disable))
845                 return;
846
847         check_sync(dev, dma_handle, size, offset, direction, true);
848 }
849 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
850
851 void debug_dma_sync_single_range_for_device(struct device *dev,
852                                             dma_addr_t dma_handle,
853                                             unsigned long offset,
854                                             size_t size, int direction)
855 {
856         if (unlikely(global_disable))
857                 return;
858
859         check_sync(dev, dma_handle, size, offset, direction, false);
860 }
861 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
862
863 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
864                                int nelems, int direction)
865 {
866         struct scatterlist *s;
867         int i;
868
869         if (unlikely(global_disable))
870                 return;
871
872         for_each_sg(sg, s, nelems, i) {
873                 check_sync(dev, s->dma_address, s->dma_length, 0,
874                                 direction, true);
875         }
876 }
877 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
878
879 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
880                                   int nelems, int direction)
881 {
882         struct scatterlist *s;
883         int i;
884
885         if (unlikely(global_disable))
886                 return;
887
888         for_each_sg(sg, s, nelems, i) {
889                 check_sync(dev, s->dma_address, s->dma_length, 0,
890                                 direction, false);
891         }
892 }
893 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
894