dma-debug: add a check dma memory leaks
[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 static int device_dma_allocations(struct device *dev)
404 {
405         struct dma_debug_entry *entry;
406         unsigned long flags;
407         int count = 0, i;
408
409         for (i = 0; i < HASH_SIZE; ++i) {
410                 spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
411                 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
412                         if (entry->dev == dev)
413                                 count += 1;
414                 }
415                 spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
416         }
417
418         return count;
419 }
420
421 static int dma_debug_device_change(struct notifier_block *nb,
422                                     unsigned long action, void *data)
423 {
424         struct device *dev = data;
425         int count;
426
427
428         switch (action) {
429         case BUS_NOTIFY_UNBIND_DRIVER:
430                 count = device_dma_allocations(dev);
431                 if (count == 0)
432                         break;
433                 err_printk(dev, NULL, "DMA-API: device driver has pending "
434                                 "DMA allocations while released from device "
435                                 "[count=%d]\n", count);
436                 break;
437         default:
438                 break;
439         }
440
441         return 0;
442 }
443
444 void dma_debug_add_bus(struct bus_type *bus)
445 {
446         struct notifier_block *nb;
447
448         nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
449         if (nb == NULL) {
450                 printk(KERN_ERR "dma_debug_add_bus: out of memory\n");
451                 return;
452         }
453
454         nb->notifier_call = dma_debug_device_change;
455
456         bus_register_notifier(bus, nb);
457 }
458
459 /*
460  * Let the architectures decide how many entries should be preallocated.
461  */
462 void dma_debug_init(u32 num_entries)
463 {
464         int i;
465
466         if (global_disable)
467                 return;
468
469         for (i = 0; i < HASH_SIZE; ++i) {
470                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
471                 dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
472         }
473
474         if (dma_debug_fs_init() != 0) {
475                 printk(KERN_ERR "DMA-API: error creating debugfs entries "
476                                 "- disabling\n");
477                 global_disable = true;
478
479                 return;
480         }
481
482         if (req_entries)
483                 num_entries = req_entries;
484
485         if (prealloc_memory(num_entries) != 0) {
486                 printk(KERN_ERR "DMA-API: debugging out of memory error "
487                                 "- disabled\n");
488                 global_disable = true;
489
490                 return;
491         }
492
493         printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
494 }
495
496 static __init int dma_debug_cmdline(char *str)
497 {
498         if (!str)
499                 return -EINVAL;
500
501         if (strncmp(str, "off", 3) == 0) {
502                 printk(KERN_INFO "DMA-API: debugging disabled on kernel "
503                                  "command line\n");
504                 global_disable = true;
505         }
506
507         return 0;
508 }
509
510 static __init int dma_debug_entries_cmdline(char *str)
511 {
512         int res;
513
514         if (!str)
515                 return -EINVAL;
516
517         res = get_option(&str, &req_entries);
518
519         if (!res)
520                 req_entries = 0;
521
522         return 0;
523 }
524
525 __setup("dma_debug=", dma_debug_cmdline);
526 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
527
528 static void check_unmap(struct dma_debug_entry *ref)
529 {
530         struct dma_debug_entry *entry;
531         struct hash_bucket *bucket;
532         unsigned long flags;
533
534         if (dma_mapping_error(ref->dev, ref->dev_addr))
535                 return;
536
537         bucket = get_hash_bucket(ref, &flags);
538         entry = hash_bucket_find(bucket, ref);
539
540         if (!entry) {
541                 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
542                            "to free DMA memory it has not allocated "
543                            "[device address=0x%016llx] [size=%llu bytes]\n",
544                            ref->dev_addr, ref->size);
545                 goto out;
546         }
547
548         if (ref->size != entry->size) {
549                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
550                            "DMA memory with different size "
551                            "[device address=0x%016llx] [map size=%llu bytes] "
552                            "[unmap size=%llu bytes]\n",
553                            ref->dev_addr, entry->size, ref->size);
554         }
555
556         if (ref->type != entry->type) {
557                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
558                            "DMA memory with wrong function "
559                            "[device address=0x%016llx] [size=%llu bytes] "
560                            "[mapped as %s] [unmapped as %s]\n",
561                            ref->dev_addr, ref->size,
562                            type2name[entry->type], type2name[ref->type]);
563         } else if ((entry->type == dma_debug_coherent) &&
564                    (ref->paddr != entry->paddr)) {
565                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
566                            "DMA memory with different CPU address "
567                            "[device address=0x%016llx] [size=%llu bytes] "
568                            "[cpu alloc address=%p] [cpu free address=%p]",
569                            ref->dev_addr, ref->size,
570                            (void *)entry->paddr, (void *)ref->paddr);
571         }
572
573         if (ref->sg_call_ents && ref->type == dma_debug_sg &&
574             ref->sg_call_ents != entry->sg_call_ents) {
575                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
576                            "DMA sg list with different entry count "
577                            "[map count=%d] [unmap count=%d]\n",
578                            entry->sg_call_ents, ref->sg_call_ents);
579         }
580
581         /*
582          * This may be no bug in reality - but most implementations of the
583          * DMA API don't handle this properly, so check for it here
584          */
585         if (ref->direction != entry->direction) {
586                 err_printk(ref->dev, entry, "DMA-API: device driver frees "
587                            "DMA memory with different direction "
588                            "[device address=0x%016llx] [size=%llu bytes] "
589                            "[mapped with %s] [unmapped with %s]\n",
590                            ref->dev_addr, ref->size,
591                            dir2name[entry->direction],
592                            dir2name[ref->direction]);
593         }
594
595         hash_bucket_del(entry);
596         dma_entry_free(entry);
597
598 out:
599         put_hash_bucket(bucket, &flags);
600 }
601
602 static void check_for_stack(struct device *dev, void *addr)
603 {
604         if (object_is_on_stack(addr))
605                 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
606                                 "stack [addr=%p]\n", addr);
607 }
608
609 static inline bool overlap(void *addr, u64 size, void *start, void *end)
610 {
611         void *addr2 = (char *)addr + size;
612
613         return ((addr >= start && addr < end) ||
614                 (addr2 >= start && addr2 < end) ||
615                 ((addr < start) && (addr2 >= end)));
616 }
617
618 static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
619 {
620         if (overlap(addr, size, _text, _etext) ||
621             overlap(addr, size, __start_rodata, __end_rodata))
622                 err_printk(dev, NULL, "DMA-API: device driver maps "
623                                 "memory from kernel text or rodata "
624                                 "[addr=%p] [size=%llu]\n", addr, size);
625 }
626
627 static void check_sync(struct device *dev, dma_addr_t addr,
628                        u64 size, u64 offset, int direction, bool to_cpu)
629 {
630         struct dma_debug_entry ref = {
631                 .dev            = dev,
632                 .dev_addr       = addr,
633                 .size           = size,
634                 .direction      = direction,
635         };
636         struct dma_debug_entry *entry;
637         struct hash_bucket *bucket;
638         unsigned long flags;
639
640         bucket = get_hash_bucket(&ref, &flags);
641
642         entry = hash_bucket_find(bucket, &ref);
643
644         if (!entry) {
645                 err_printk(dev, NULL, "DMA-API: device driver tries "
646                                 "to sync DMA memory it has not allocated "
647                                 "[device address=0x%016llx] [size=%llu bytes]\n",
648                                 addr, size);
649                 goto out;
650         }
651
652         if ((offset + size) > entry->size) {
653                 err_printk(dev, entry, "DMA-API: device driver syncs"
654                                 " DMA memory outside allocated range "
655                                 "[device address=0x%016llx] "
656                                 "[allocation size=%llu bytes] [sync offset=%llu] "
657                                 "[sync size=%llu]\n", entry->dev_addr, entry->size,
658                                 offset, size);
659         }
660
661         if (direction != entry->direction) {
662                 err_printk(dev, entry, "DMA-API: device driver syncs "
663                                 "DMA memory with different direction "
664                                 "[device address=0x%016llx] [size=%llu bytes] "
665                                 "[mapped with %s] [synced with %s]\n",
666                                 addr, entry->size,
667                                 dir2name[entry->direction],
668                                 dir2name[direction]);
669         }
670
671         if (entry->direction == DMA_BIDIRECTIONAL)
672                 goto out;
673
674         if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
675                       !(direction == DMA_TO_DEVICE))
676                 err_printk(dev, entry, "DMA-API: device driver syncs "
677                                 "device read-only DMA memory for cpu "
678                                 "[device address=0x%016llx] [size=%llu bytes] "
679                                 "[mapped with %s] [synced with %s]\n",
680                                 addr, entry->size,
681                                 dir2name[entry->direction],
682                                 dir2name[direction]);
683
684         if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
685                        !(direction == DMA_FROM_DEVICE))
686                 err_printk(dev, entry, "DMA-API: device driver syncs "
687                                 "device write-only DMA memory to device "
688                                 "[device address=0x%016llx] [size=%llu bytes] "
689                                 "[mapped with %s] [synced with %s]\n",
690                                 addr, entry->size,
691                                 dir2name[entry->direction],
692                                 dir2name[direction]);
693
694 out:
695         put_hash_bucket(bucket, &flags);
696
697 }
698
699 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
700                         size_t size, int direction, dma_addr_t dma_addr,
701                         bool map_single)
702 {
703         struct dma_debug_entry *entry;
704
705         if (unlikely(global_disable))
706                 return;
707
708         if (unlikely(dma_mapping_error(dev, dma_addr)))
709                 return;
710
711         entry = dma_entry_alloc();
712         if (!entry)
713                 return;
714
715         entry->dev       = dev;
716         entry->type      = dma_debug_page;
717         entry->paddr     = page_to_phys(page) + offset;
718         entry->dev_addr  = dma_addr;
719         entry->size      = size;
720         entry->direction = direction;
721
722         if (map_single) {
723                 void *addr = ((char *)page_address(page)) + offset;
724
725                 entry->type = dma_debug_single;
726                 check_for_stack(dev, addr);
727                 check_for_illegal_area(dev, addr, size);
728         }
729
730         add_dma_entry(entry);
731 }
732 EXPORT_SYMBOL(debug_dma_map_page);
733
734 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
735                           size_t size, int direction, bool map_single)
736 {
737         struct dma_debug_entry ref = {
738                 .type           = dma_debug_page,
739                 .dev            = dev,
740                 .dev_addr       = addr,
741                 .size           = size,
742                 .direction      = direction,
743         };
744
745         if (unlikely(global_disable))
746                 return;
747
748         if (map_single)
749                 ref.type = dma_debug_single;
750
751         check_unmap(&ref);
752 }
753 EXPORT_SYMBOL(debug_dma_unmap_page);
754
755 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
756                       int nents, int mapped_ents, int direction)
757 {
758         struct dma_debug_entry *entry;
759         struct scatterlist *s;
760         int i;
761
762         if (unlikely(global_disable))
763                 return;
764
765         for_each_sg(sg, s, mapped_ents, i) {
766                 entry = dma_entry_alloc();
767                 if (!entry)
768                         return;
769
770                 entry->type           = dma_debug_sg;
771                 entry->dev            = dev;
772                 entry->paddr          = sg_phys(s);
773                 entry->size           = s->length;
774                 entry->dev_addr       = s->dma_address;
775                 entry->direction      = direction;
776                 entry->sg_call_ents   = nents;
777                 entry->sg_mapped_ents = mapped_ents;
778
779                 check_for_stack(dev, sg_virt(s));
780                 check_for_illegal_area(dev, sg_virt(s), s->length);
781
782                 add_dma_entry(entry);
783         }
784 }
785 EXPORT_SYMBOL(debug_dma_map_sg);
786
787 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
788                         int nelems, int dir)
789 {
790         struct dma_debug_entry *entry;
791         struct scatterlist *s;
792         int mapped_ents = 0, i;
793         unsigned long flags;
794
795         if (unlikely(global_disable))
796                 return;
797
798         for_each_sg(sglist, s, nelems, i) {
799
800                 struct dma_debug_entry ref = {
801                         .type           = dma_debug_sg,
802                         .dev            = dev,
803                         .paddr          = sg_phys(s),
804                         .dev_addr       = s->dma_address,
805                         .size           = s->length,
806                         .direction      = dir,
807                         .sg_call_ents   = 0,
808                 };
809
810                 if (mapped_ents && i >= mapped_ents)
811                         break;
812
813                 if (mapped_ents == 0) {
814                         struct hash_bucket *bucket;
815                         ref.sg_call_ents = nelems;
816                         bucket = get_hash_bucket(&ref, &flags);
817                         entry = hash_bucket_find(bucket, &ref);
818                         if (entry)
819                                 mapped_ents = entry->sg_mapped_ents;
820                         put_hash_bucket(bucket, &flags);
821                 }
822
823                 check_unmap(&ref);
824         }
825 }
826 EXPORT_SYMBOL(debug_dma_unmap_sg);
827
828 void debug_dma_alloc_coherent(struct device *dev, size_t size,
829                               dma_addr_t dma_addr, void *virt)
830 {
831         struct dma_debug_entry *entry;
832
833         if (unlikely(global_disable))
834                 return;
835
836         if (unlikely(virt == NULL))
837                 return;
838
839         entry = dma_entry_alloc();
840         if (!entry)
841                 return;
842
843         entry->type      = dma_debug_coherent;
844         entry->dev       = dev;
845         entry->paddr     = virt_to_phys(virt);
846         entry->size      = size;
847         entry->dev_addr  = dma_addr;
848         entry->direction = DMA_BIDIRECTIONAL;
849
850         add_dma_entry(entry);
851 }
852 EXPORT_SYMBOL(debug_dma_alloc_coherent);
853
854 void debug_dma_free_coherent(struct device *dev, size_t size,
855                          void *virt, dma_addr_t addr)
856 {
857         struct dma_debug_entry ref = {
858                 .type           = dma_debug_coherent,
859                 .dev            = dev,
860                 .paddr          = virt_to_phys(virt),
861                 .dev_addr       = addr,
862                 .size           = size,
863                 .direction      = DMA_BIDIRECTIONAL,
864         };
865
866         if (unlikely(global_disable))
867                 return;
868
869         check_unmap(&ref);
870 }
871 EXPORT_SYMBOL(debug_dma_free_coherent);
872
873 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
874                                    size_t size, int direction)
875 {
876         if (unlikely(global_disable))
877                 return;
878
879         check_sync(dev, dma_handle, size, 0, direction, true);
880 }
881 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
882
883 void debug_dma_sync_single_for_device(struct device *dev,
884                                       dma_addr_t dma_handle, size_t size,
885                                       int direction)
886 {
887         if (unlikely(global_disable))
888                 return;
889
890         check_sync(dev, dma_handle, size, 0, direction, false);
891 }
892 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
893
894 void debug_dma_sync_single_range_for_cpu(struct device *dev,
895                                          dma_addr_t dma_handle,
896                                          unsigned long offset, size_t size,
897                                          int direction)
898 {
899         if (unlikely(global_disable))
900                 return;
901
902         check_sync(dev, dma_handle, size, offset, direction, true);
903 }
904 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
905
906 void debug_dma_sync_single_range_for_device(struct device *dev,
907                                             dma_addr_t dma_handle,
908                                             unsigned long offset,
909                                             size_t size, int direction)
910 {
911         if (unlikely(global_disable))
912                 return;
913
914         check_sync(dev, dma_handle, size, offset, direction, false);
915 }
916 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
917
918 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
919                                int nelems, int direction)
920 {
921         struct scatterlist *s;
922         int i;
923
924         if (unlikely(global_disable))
925                 return;
926
927         for_each_sg(sg, s, nelems, i) {
928                 check_sync(dev, s->dma_address, s->dma_length, 0,
929                                 direction, true);
930         }
931 }
932 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
933
934 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
935                                   int nelems, int direction)
936 {
937         struct scatterlist *s;
938         int i;
939
940         if (unlikely(global_disable))
941                 return;
942
943         for_each_sg(sg, s, nelems, i) {
944                 check_sync(dev, s->dma_address, s->dma_length, 0,
945                                 direction, false);
946         }
947 }
948 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
949