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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/vmalloc.h>
26#include <linux/debugfs.h>
27#include <linux/uaccess.h>
28#include <linux/export.h>
29#include <linux/device.h>
30#include <linux/types.h>
31#include <linux/sched.h>
32#include <linux/ctype.h>
33#include <linux/list.h>
34#include <linux/slab.h>
35
36#include <asm/sections.h>
37
38#define HASH_SIZE 1024ULL
39#define HASH_FN_SHIFT 13
40#define HASH_FN_MASK (HASH_SIZE - 1)
41
42enum {
43 dma_debug_single,
44 dma_debug_page,
45 dma_debug_sg,
46 dma_debug_coherent,
47 dma_debug_resource,
48};
49
50enum map_err_types {
51 MAP_ERR_CHECK_NOT_APPLICABLE,
52 MAP_ERR_NOT_CHECKED,
53 MAP_ERR_CHECKED,
54};
55
56#define DMA_DEBUG_STACKTRACE_ENTRIES 5
57
58/**
59 * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
60 * @list: node on pre-allocated free_entries list
61 * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
62 * @type: single, page, sg, coherent
63 * @pfn: page frame of the start address
64 * @offset: offset of mapping relative to pfn
65 * @size: length of the mapping
66 * @direction: enum dma_data_direction
67 * @sg_call_ents: 'nents' from dma_map_sg
68 * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
69 * @map_err_type: track whether dma_mapping_error() was checked
70 * @stacktrace: support backtraces when a violation is detected
71 */
72struct dma_debug_entry {
73 struct list_head list;
74 struct device *dev;
75 int type;
76 unsigned long pfn;
77 size_t offset;
78 u64 dev_addr;
79 u64 size;
80 int direction;
81 int sg_call_ents;
82 int sg_mapped_ents;
83 enum map_err_types map_err_type;
84#ifdef CONFIG_STACKTRACE
85 struct stack_trace stacktrace;
86 unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
87#endif
88};
89
90typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
91
92struct hash_bucket {
93 struct list_head list;
94 spinlock_t lock;
95} ____cacheline_aligned_in_smp;
96
97/* Hash list to save the allocated dma addresses */
98static struct hash_bucket dma_entry_hash[HASH_SIZE];
99/* List of pre-allocated dma_debug_entry's */
100static LIST_HEAD(free_entries);
101/* Lock for the list above */
102static DEFINE_SPINLOCK(free_entries_lock);
103
104/* Global disable flag - will be set in case of an error */
105static bool global_disable __read_mostly;
106
107/* Early initialization disable flag, set at the end of dma_debug_init */
108static bool dma_debug_initialized __read_mostly;
109
110static inline bool dma_debug_disabled(void)
111{
112 return global_disable || !dma_debug_initialized;
113}
114
115/* Global error count */
116static u32 error_count;
117
118/* Global error show enable*/
119static u32 show_all_errors __read_mostly;
120/* Number of errors to show */
121static u32 show_num_errors = 1;
122
123static u32 num_free_entries;
124static u32 min_free_entries;
125static u32 nr_total_entries;
126
127/* number of preallocated entries requested by kernel cmdline */
128static u32 req_entries;
129
130/* debugfs dentry's for the stuff above */
131static struct dentry *dma_debug_dent __read_mostly;
132static struct dentry *global_disable_dent __read_mostly;
133static struct dentry *error_count_dent __read_mostly;
134static struct dentry *show_all_errors_dent __read_mostly;
135static struct dentry *show_num_errors_dent __read_mostly;
136static struct dentry *num_free_entries_dent __read_mostly;
137static struct dentry *min_free_entries_dent __read_mostly;
138static struct dentry *filter_dent __read_mostly;
139
140/* per-driver filter related state */
141
142#define NAME_MAX_LEN 64
143
144static char current_driver_name[NAME_MAX_LEN] __read_mostly;
145static struct device_driver *current_driver __read_mostly;
146
147static DEFINE_RWLOCK(driver_name_lock);
148
149static const char *const maperr2str[] = {
150 [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
151 [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
152 [MAP_ERR_CHECKED] = "dma map error checked",
153};
154
155static const char *type2name[5] = { "single", "page",
156 "scather-gather", "coherent",
157 "resource" };
158
159static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
160 "DMA_FROM_DEVICE", "DMA_NONE" };
161
162/*
163 * The access to some variables in this macro is racy. We can't use atomic_t
164 * here because all these variables are exported to debugfs. Some of them even
165 * writeable. This is also the reason why a lock won't help much. But anyway,
166 * the races are no big deal. Here is why:
167 *
168 * error_count: the addition is racy, but the worst thing that can happen is
169 * that we don't count some errors
170 * show_num_errors: the subtraction is racy. Also no big deal because in
171 * worst case this will result in one warning more in the
172 * system log than the user configured. This variable is
173 * writeable via debugfs.
174 */
175static inline void dump_entry_trace(struct dma_debug_entry *entry)
176{
177#ifdef CONFIG_STACKTRACE
178 if (entry) {
179 pr_warning("Mapped at:\n");
180 print_stack_trace(&entry->stacktrace, 0);
181 }
182#endif
183}
184
185static bool driver_filter(struct device *dev)
186{
187 struct device_driver *drv;
188 unsigned long flags;
189 bool ret;
190
191 /* driver filter off */
192 if (likely(!current_driver_name[0]))
193 return true;
194
195 /* driver filter on and initialized */
196 if (current_driver && dev && dev->driver == current_driver)
197 return true;
198
199 /* driver filter on, but we can't filter on a NULL device... */
200 if (!dev)
201 return false;
202
203 if (current_driver || !current_driver_name[0])
204 return false;
205
206 /* driver filter on but not yet initialized */
207 drv = dev->driver;
208 if (!drv)
209 return false;
210
211 /* lock to protect against change of current_driver_name */
212 read_lock_irqsave(&driver_name_lock, flags);
213
214 ret = false;
215 if (drv->name &&
216 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
217 current_driver = drv;
218 ret = true;
219 }
220
221 read_unlock_irqrestore(&driver_name_lock, flags);
222
223 return ret;
224}
225
226#define err_printk(dev, entry, format, arg...) do { \
227 error_count += 1; \
228 if (driver_filter(dev) && \
229 (show_all_errors || show_num_errors > 0)) { \
230 WARN(1, "%s %s: " format, \
231 dev ? dev_driver_string(dev) : "NULL", \
232 dev ? dev_name(dev) : "NULL", ## arg); \
233 dump_entry_trace(entry); \
234 } \
235 if (!show_all_errors && show_num_errors > 0) \
236 show_num_errors -= 1; \
237 } while (0);
238
239/*
240 * Hash related functions
241 *
242 * Every DMA-API request is saved into a struct dma_debug_entry. To
243 * have quick access to these structs they are stored into a hash.
244 */
245static int hash_fn(struct dma_debug_entry *entry)
246{
247 /*
248 * Hash function is based on the dma address.
249 * We use bits 20-27 here as the index into the hash
250 */
251 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
252}
253
254/*
255 * Request exclusive access to a hash bucket for a given dma_debug_entry.
256 */
257static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
258 unsigned long *flags)
259 __acquires(&dma_entry_hash[idx].lock)
260{
261 int idx = hash_fn(entry);
262 unsigned long __flags;
263
264 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
265 *flags = __flags;
266 return &dma_entry_hash[idx];
267}
268
269/*
270 * Give up exclusive access to the hash bucket
271 */
272static void put_hash_bucket(struct hash_bucket *bucket,
273 unsigned long *flags)
274 __releases(&bucket->lock)
275{
276 unsigned long __flags = *flags;
277
278 spin_unlock_irqrestore(&bucket->lock, __flags);
279}
280
281static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
282{
283 return ((a->dev_addr == b->dev_addr) &&
284 (a->dev == b->dev)) ? true : false;
285}
286
287static bool containing_match(struct dma_debug_entry *a,
288 struct dma_debug_entry *b)
289{
290 if (a->dev != b->dev)
291 return false;
292
293 if ((b->dev_addr <= a->dev_addr) &&
294 ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
295 return true;
296
297 return false;
298}
299
300/*
301 * Search a given entry in the hash bucket list
302 */
303static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
304 struct dma_debug_entry *ref,
305 match_fn match)
306{
307 struct dma_debug_entry *entry, *ret = NULL;
308 int matches = 0, match_lvl, last_lvl = -1;
309
310 list_for_each_entry(entry, &bucket->list, list) {
311 if (!match(ref, entry))
312 continue;
313
314 /*
315 * Some drivers map the same physical address multiple
316 * times. Without a hardware IOMMU this results in the
317 * same device addresses being put into the dma-debug
318 * hash multiple times too. This can result in false
319 * positives being reported. Therefore we implement a
320 * best-fit algorithm here which returns the entry from
321 * the hash which fits best to the reference value
322 * instead of the first-fit.
323 */
324 matches += 1;
325 match_lvl = 0;
326 entry->size == ref->size ? ++match_lvl : 0;
327 entry->type == ref->type ? ++match_lvl : 0;
328 entry->direction == ref->direction ? ++match_lvl : 0;
329 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
330
331 if (match_lvl == 4) {
332 /* perfect-fit - return the result */
333 return entry;
334 } else if (match_lvl > last_lvl) {
335 /*
336 * We found an entry that fits better then the
337 * previous one or it is the 1st match.
338 */
339 last_lvl = match_lvl;
340 ret = entry;
341 }
342 }
343
344 /*
345 * If we have multiple matches but no perfect-fit, just return
346 * NULL.
347 */
348 ret = (matches == 1) ? ret : NULL;
349
350 return ret;
351}
352
353static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
354 struct dma_debug_entry *ref)
355{
356 return __hash_bucket_find(bucket, ref, exact_match);
357}
358
359static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
360 struct dma_debug_entry *ref,
361 unsigned long *flags)
362{
363
364 unsigned int max_range = dma_get_max_seg_size(ref->dev);
365 struct dma_debug_entry *entry, index = *ref;
366 unsigned int range = 0;
367
368 while (range <= max_range) {
369 entry = __hash_bucket_find(*bucket, ref, containing_match);
370
371 if (entry)
372 return entry;
373
374 /*
375 * Nothing found, go back a hash bucket
376 */
377 put_hash_bucket(*bucket, flags);
378 range += (1 << HASH_FN_SHIFT);
379 index.dev_addr -= (1 << HASH_FN_SHIFT);
380 *bucket = get_hash_bucket(&index, flags);
381 }
382
383 return NULL;
384}
385
386/*
387 * Add an entry to a hash bucket
388 */
389static void hash_bucket_add(struct hash_bucket *bucket,
390 struct dma_debug_entry *entry)
391{
392 list_add_tail(&entry->list, &bucket->list);
393}
394
395/*
396 * Remove entry from a hash bucket list
397 */
398static void hash_bucket_del(struct dma_debug_entry *entry)
399{
400 list_del(&entry->list);
401}
402
403static unsigned long long phys_addr(struct dma_debug_entry *entry)
404{
405 if (entry->type == dma_debug_resource)
406 return __pfn_to_phys(entry->pfn) + entry->offset;
407
408 return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
409}
410
411/*
412 * Dump mapping entries for debugging purposes
413 */
414void debug_dma_dump_mappings(struct device *dev)
415{
416 int idx;
417
418 for (idx = 0; idx < HASH_SIZE; idx++) {
419 struct hash_bucket *bucket = &dma_entry_hash[idx];
420 struct dma_debug_entry *entry;
421 unsigned long flags;
422
423 spin_lock_irqsave(&bucket->lock, flags);
424
425 list_for_each_entry(entry, &bucket->list, list) {
426 if (!dev || dev == entry->dev) {
427 dev_info(entry->dev,
428 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
429 type2name[entry->type], idx,
430 phys_addr(entry), entry->pfn,
431 entry->dev_addr, entry->size,
432 dir2name[entry->direction],
433 maperr2str[entry->map_err_type]);
434 }
435 }
436
437 spin_unlock_irqrestore(&bucket->lock, flags);
438 }
439}
440EXPORT_SYMBOL(debug_dma_dump_mappings);
441
442/*
443 * For each mapping (initial cacheline in the case of
444 * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
445 * scatterlist, or the cacheline specified in dma_map_single) insert
446 * into this tree using the cacheline as the key. At
447 * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If
448 * the entry already exists at insertion time add a tag as a reference
449 * count for the overlapping mappings. For now, the overlap tracking
450 * just ensures that 'unmaps' balance 'maps' before marking the
451 * cacheline idle, but we should also be flagging overlaps as an API
452 * violation.
453 *
454 * Memory usage is mostly constrained by the maximum number of available
455 * dma-debug entries in that we need a free dma_debug_entry before
456 * inserting into the tree. In the case of dma_map_page and
457 * dma_alloc_coherent there is only one dma_debug_entry and one
458 * dma_active_cacheline entry to track per event. dma_map_sg(), on the
459 * other hand, consumes a single dma_debug_entry, but inserts 'nents'
460 * entries into the tree.
461 *
462 * At any time debug_dma_assert_idle() can be called to trigger a
463 * warning if any cachelines in the given page are in the active set.
464 */
465static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
466static DEFINE_SPINLOCK(radix_lock);
467#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
468#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
469#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
470
471static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
472{
473 return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
474 (entry->offset >> L1_CACHE_SHIFT);
475}
476
477static int active_cacheline_read_overlap(phys_addr_t cln)
478{
479 int overlap = 0, i;
480
481 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
482 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
483 overlap |= 1 << i;
484 return overlap;
485}
486
487static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
488{
489 int i;
490
491 if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
492 return overlap;
493
494 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
495 if (overlap & 1 << i)
496 radix_tree_tag_set(&dma_active_cacheline, cln, i);
497 else
498 radix_tree_tag_clear(&dma_active_cacheline, cln, i);
499
500 return overlap;
501}
502
503static void active_cacheline_inc_overlap(phys_addr_t cln)
504{
505 int overlap = active_cacheline_read_overlap(cln);
506
507 overlap = active_cacheline_set_overlap(cln, ++overlap);
508
509 /* If we overflowed the overlap counter then we're potentially
510 * leaking dma-mappings. Otherwise, if maps and unmaps are
511 * balanced then this overflow may cause false negatives in
512 * debug_dma_assert_idle() as the cacheline may be marked idle
513 * prematurely.
514 */
515 WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
516 "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
517 ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
518}
519
520static int active_cacheline_dec_overlap(phys_addr_t cln)
521{
522 int overlap = active_cacheline_read_overlap(cln);
523
524 return active_cacheline_set_overlap(cln, --overlap);
525}
526
527static int active_cacheline_insert(struct dma_debug_entry *entry)
528{
529 phys_addr_t cln = to_cacheline_number(entry);
530 unsigned long flags;
531 int rc;
532
533 /* If the device is not writing memory then we don't have any
534 * concerns about the cpu consuming stale data. This mitigates
535 * legitimate usages of overlapping mappings.
536 */
537 if (entry->direction == DMA_TO_DEVICE)
538 return 0;
539
540 spin_lock_irqsave(&radix_lock, flags);
541 rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
542 if (rc == -EEXIST)
543 active_cacheline_inc_overlap(cln);
544 spin_unlock_irqrestore(&radix_lock, flags);
545
546 return rc;
547}
548
549static void active_cacheline_remove(struct dma_debug_entry *entry)
550{
551 phys_addr_t cln = to_cacheline_number(entry);
552 unsigned long flags;
553
554 /* ...mirror the insert case */
555 if (entry->direction == DMA_TO_DEVICE)
556 return;
557
558 spin_lock_irqsave(&radix_lock, flags);
559 /* since we are counting overlaps the final put of the
560 * cacheline will occur when the overlap count is 0.
561 * active_cacheline_dec_overlap() returns -1 in that case
562 */
563 if (active_cacheline_dec_overlap(cln) < 0)
564 radix_tree_delete(&dma_active_cacheline, cln);
565 spin_unlock_irqrestore(&radix_lock, flags);
566}
567
568/**
569 * debug_dma_assert_idle() - assert that a page is not undergoing dma
570 * @page: page to lookup in the dma_active_cacheline tree
571 *
572 * Place a call to this routine in cases where the cpu touching the page
573 * before the dma completes (page is dma_unmapped) will lead to data
574 * corruption.
575 */
576void debug_dma_assert_idle(struct page *page)
577{
578 static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
579 struct dma_debug_entry *entry = NULL;
580 void **results = (void **) &ents;
581 unsigned int nents, i;
582 unsigned long flags;
583 phys_addr_t cln;
584
585 if (dma_debug_disabled())
586 return;
587
588 if (!page)
589 return;
590
591 cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
592 spin_lock_irqsave(&radix_lock, flags);
593 nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
594 CACHELINES_PER_PAGE);
595 for (i = 0; i < nents; i++) {
596 phys_addr_t ent_cln = to_cacheline_number(ents[i]);
597
598 if (ent_cln == cln) {
599 entry = ents[i];
600 break;
601 } else if (ent_cln >= cln + CACHELINES_PER_PAGE)
602 break;
603 }
604 spin_unlock_irqrestore(&radix_lock, flags);
605
606 if (!entry)
607 return;
608
609 cln = to_cacheline_number(entry);
610 err_printk(entry->dev, entry,
611 "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
612 &cln);
613}
614
615/*
616 * Wrapper function for adding an entry to the hash.
617 * This function takes care of locking itself.
618 */
619static void add_dma_entry(struct dma_debug_entry *entry)
620{
621 struct hash_bucket *bucket;
622 unsigned long flags;
623 int rc;
624
625 bucket = get_hash_bucket(entry, &flags);
626 hash_bucket_add(bucket, entry);
627 put_hash_bucket(bucket, &flags);
628
629 rc = active_cacheline_insert(entry);
630 if (rc == -ENOMEM) {
631 pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
632 global_disable = true;
633 }
634
635 /* TODO: report -EEXIST errors here as overlapping mappings are
636 * not supported by the DMA API
637 */
638}
639
640static struct dma_debug_entry *__dma_entry_alloc(void)
641{
642 struct dma_debug_entry *entry;
643
644 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
645 list_del(&entry->list);
646 memset(entry, 0, sizeof(*entry));
647
648 num_free_entries -= 1;
649 if (num_free_entries < min_free_entries)
650 min_free_entries = num_free_entries;
651
652 return entry;
653}
654
655/* struct dma_entry allocator
656 *
657 * The next two functions implement the allocator for
658 * struct dma_debug_entries.
659 */
660static struct dma_debug_entry *dma_entry_alloc(void)
661{
662 struct dma_debug_entry *entry;
663 unsigned long flags;
664
665 spin_lock_irqsave(&free_entries_lock, flags);
666
667 if (list_empty(&free_entries)) {
668 global_disable = true;
669 spin_unlock_irqrestore(&free_entries_lock, flags);
670 pr_err("DMA-API: debugging out of memory - disabling\n");
671 return NULL;
672 }
673
674 entry = __dma_entry_alloc();
675
676 spin_unlock_irqrestore(&free_entries_lock, flags);
677
678#ifdef CONFIG_STACKTRACE
679 entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
680 entry->stacktrace.entries = entry->st_entries;
681 entry->stacktrace.skip = 2;
682 save_stack_trace(&entry->stacktrace);
683#endif
684
685 return entry;
686}
687
688static void dma_entry_free(struct dma_debug_entry *entry)
689{
690 unsigned long flags;
691
692 active_cacheline_remove(entry);
693
694 /*
695 * add to beginning of the list - this way the entries are
696 * more likely cache hot when they are reallocated.
697 */
698 spin_lock_irqsave(&free_entries_lock, flags);
699 list_add(&entry->list, &free_entries);
700 num_free_entries += 1;
701 spin_unlock_irqrestore(&free_entries_lock, flags);
702}
703
704int dma_debug_resize_entries(u32 num_entries)
705{
706 int i, delta, ret = 0;
707 unsigned long flags;
708 struct dma_debug_entry *entry;
709 LIST_HEAD(tmp);
710
711 spin_lock_irqsave(&free_entries_lock, flags);
712
713 if (nr_total_entries < num_entries) {
714 delta = num_entries - nr_total_entries;
715
716 spin_unlock_irqrestore(&free_entries_lock, flags);
717
718 for (i = 0; i < delta; i++) {
719 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
720 if (!entry)
721 break;
722
723 list_add_tail(&entry->list, &tmp);
724 }
725
726 spin_lock_irqsave(&free_entries_lock, flags);
727
728 list_splice(&tmp, &free_entries);
729 nr_total_entries += i;
730 num_free_entries += i;
731 } else {
732 delta = nr_total_entries - num_entries;
733
734 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
735 entry = __dma_entry_alloc();
736 kfree(entry);
737 }
738
739 nr_total_entries -= i;
740 }
741
742 if (nr_total_entries != num_entries)
743 ret = 1;
744
745 spin_unlock_irqrestore(&free_entries_lock, flags);
746
747 return ret;
748}
749EXPORT_SYMBOL(dma_debug_resize_entries);
750
751/*
752 * DMA-API debugging init code
753 *
754 * The init code does two things:
755 * 1. Initialize core data structures
756 * 2. Preallocate a given number of dma_debug_entry structs
757 */
758
759static int prealloc_memory(u32 num_entries)
760{
761 struct dma_debug_entry *entry, *next_entry;
762 int i;
763
764 for (i = 0; i < num_entries; ++i) {
765 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
766 if (!entry)
767 goto out_err;
768
769 list_add_tail(&entry->list, &free_entries);
770 }
771
772 num_free_entries = num_entries;
773 min_free_entries = num_entries;
774
775 pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
776
777 return 0;
778
779out_err:
780
781 list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
782 list_del(&entry->list);
783 kfree(entry);
784 }
785
786 return -ENOMEM;
787}
788
789static ssize_t filter_read(struct file *file, char __user *user_buf,
790 size_t count, loff_t *ppos)
791{
792 char buf[NAME_MAX_LEN + 1];
793 unsigned long flags;
794 int len;
795
796 if (!current_driver_name[0])
797 return 0;
798
799 /*
800 * We can't copy to userspace directly because current_driver_name can
801 * only be read under the driver_name_lock with irqs disabled. So
802 * create a temporary copy first.
803 */
804 read_lock_irqsave(&driver_name_lock, flags);
805 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
806 read_unlock_irqrestore(&driver_name_lock, flags);
807
808 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
809}
810
811static ssize_t filter_write(struct file *file, const char __user *userbuf,
812 size_t count, loff_t *ppos)
813{
814 char buf[NAME_MAX_LEN];
815 unsigned long flags;
816 size_t len;
817 int i;
818
819 /*
820 * We can't copy from userspace directly. Access to
821 * current_driver_name is protected with a write_lock with irqs
822 * disabled. Since copy_from_user can fault and may sleep we
823 * need to copy to temporary buffer first
824 */
825 len = min(count, (size_t)(NAME_MAX_LEN - 1));
826 if (copy_from_user(buf, userbuf, len))
827 return -EFAULT;
828
829 buf[len] = 0;
830
831 write_lock_irqsave(&driver_name_lock, flags);
832
833 /*
834 * Now handle the string we got from userspace very carefully.
835 * The rules are:
836 * - only use the first token we got
837 * - token delimiter is everything looking like a space
838 * character (' ', '\n', '\t' ...)
839 *
840 */
841 if (!isalnum(buf[0])) {
842 /*
843 * If the first character userspace gave us is not
844 * alphanumerical then assume the filter should be
845 * switched off.
846 */
847 if (current_driver_name[0])
848 pr_info("DMA-API: switching off dma-debug driver filter\n");
849 current_driver_name[0] = 0;
850 current_driver = NULL;
851 goto out_unlock;
852 }
853
854 /*
855 * Now parse out the first token and use it as the name for the
856 * driver to filter for.
857 */
858 for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
859 current_driver_name[i] = buf[i];
860 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
861 break;
862 }
863 current_driver_name[i] = 0;
864 current_driver = NULL;
865
866 pr_info("DMA-API: enable driver filter for driver [%s]\n",
867 current_driver_name);
868
869out_unlock:
870 write_unlock_irqrestore(&driver_name_lock, flags);
871
872 return count;
873}
874
875static const struct file_operations filter_fops = {
876 .read = filter_read,
877 .write = filter_write,
878 .llseek = default_llseek,
879};
880
881static int dma_debug_fs_init(void)
882{
883 dma_debug_dent = debugfs_create_dir("dma-api", NULL);
884 if (!dma_debug_dent) {
885 pr_err("DMA-API: can not create debugfs directory\n");
886 return -ENOMEM;
887 }
888
889 global_disable_dent = debugfs_create_bool("disabled", 0444,
890 dma_debug_dent,
891 &global_disable);
892 if (!global_disable_dent)
893 goto out_err;
894
895 error_count_dent = debugfs_create_u32("error_count", 0444,
896 dma_debug_dent, &error_count);
897 if (!error_count_dent)
898 goto out_err;
899
900 show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
901 dma_debug_dent,
902 &show_all_errors);
903 if (!show_all_errors_dent)
904 goto out_err;
905
906 show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
907 dma_debug_dent,
908 &show_num_errors);
909 if (!show_num_errors_dent)
910 goto out_err;
911
912 num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
913 dma_debug_dent,
914 &num_free_entries);
915 if (!num_free_entries_dent)
916 goto out_err;
917
918 min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
919 dma_debug_dent,
920 &min_free_entries);
921 if (!min_free_entries_dent)
922 goto out_err;
923
924 filter_dent = debugfs_create_file("driver_filter", 0644,
925 dma_debug_dent, NULL, &filter_fops);
926 if (!filter_dent)
927 goto out_err;
928
929 return 0;
930
931out_err:
932 debugfs_remove_recursive(dma_debug_dent);
933
934 return -ENOMEM;
935}
936
937static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
938{
939 struct dma_debug_entry *entry;
940 unsigned long flags;
941 int count = 0, i;
942
943 local_irq_save(flags);
944
945 for (i = 0; i < HASH_SIZE; ++i) {
946 spin_lock(&dma_entry_hash[i].lock);
947 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
948 if (entry->dev == dev) {
949 count += 1;
950 *out_entry = entry;
951 }
952 }
953 spin_unlock(&dma_entry_hash[i].lock);
954 }
955
956 local_irq_restore(flags);
957
958 return count;
959}
960
961static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
962{
963 struct device *dev = data;
964 struct dma_debug_entry *uninitialized_var(entry);
965 int count;
966
967 if (dma_debug_disabled())
968 return 0;
969
970 switch (action) {
971 case BUS_NOTIFY_UNBOUND_DRIVER:
972 count = device_dma_allocations(dev, &entry);
973 if (count == 0)
974 break;
975 err_printk(dev, entry, "DMA-API: device driver has pending "
976 "DMA allocations while released from device "
977 "[count=%d]\n"
978 "One of leaked entries details: "
979 "[device address=0x%016llx] [size=%llu bytes] "
980 "[mapped with %s] [mapped as %s]\n",
981 count, entry->dev_addr, entry->size,
982 dir2name[entry->direction], type2name[entry->type]);
983 break;
984 default:
985 break;
986 }
987
988 return 0;
989}
990
991void dma_debug_add_bus(struct bus_type *bus)
992{
993 struct notifier_block *nb;
994
995 if (dma_debug_disabled())
996 return;
997
998 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
999 if (nb == NULL) {
1000 pr_err("dma_debug_add_bus: out of memory\n");
1001 return;
1002 }
1003
1004 nb->notifier_call = dma_debug_device_change;
1005
1006 bus_register_notifier(bus, nb);
1007}
1008
1009/*
1010 * Let the architectures decide how many entries should be preallocated.
1011 */
1012void dma_debug_init(u32 num_entries)
1013{
1014 int i;
1015
1016 /* Do not use dma_debug_initialized here, since we really want to be
1017 * called to set dma_debug_initialized
1018 */
1019 if (global_disable)
1020 return;
1021
1022 for (i = 0; i < HASH_SIZE; ++i) {
1023 INIT_LIST_HEAD(&dma_entry_hash[i].list);
1024 spin_lock_init(&dma_entry_hash[i].lock);
1025 }
1026
1027 if (dma_debug_fs_init() != 0) {
1028 pr_err("DMA-API: error creating debugfs entries - disabling\n");
1029 global_disable = true;
1030
1031 return;
1032 }
1033
1034 if (req_entries)
1035 num_entries = req_entries;
1036
1037 if (prealloc_memory(num_entries) != 0) {
1038 pr_err("DMA-API: debugging out of memory error - disabled\n");
1039 global_disable = true;
1040
1041 return;
1042 }
1043
1044 nr_total_entries = num_free_entries;
1045
1046 dma_debug_initialized = true;
1047
1048 pr_info("DMA-API: debugging enabled by kernel config\n");
1049}
1050
1051static __init int dma_debug_cmdline(char *str)
1052{
1053 if (!str)
1054 return -EINVAL;
1055
1056 if (strncmp(str, "off", 3) == 0) {
1057 pr_info("DMA-API: debugging disabled on kernel command line\n");
1058 global_disable = true;
1059 }
1060
1061 return 0;
1062}
1063
1064static __init int dma_debug_entries_cmdline(char *str)
1065{
1066 int res;
1067
1068 if (!str)
1069 return -EINVAL;
1070
1071 res = get_option(&str, &req_entries);
1072
1073 if (!res)
1074 req_entries = 0;
1075
1076 return 0;
1077}
1078
1079__setup("dma_debug=", dma_debug_cmdline);
1080__setup("dma_debug_entries=", dma_debug_entries_cmdline);
1081
1082static void check_unmap(struct dma_debug_entry *ref)
1083{
1084 struct dma_debug_entry *entry;
1085 struct hash_bucket *bucket;
1086 unsigned long flags;
1087
1088 bucket = get_hash_bucket(ref, &flags);
1089 entry = bucket_find_exact(bucket, ref);
1090
1091 if (!entry) {
1092 /* must drop lock before calling dma_mapping_error */
1093 put_hash_bucket(bucket, &flags);
1094
1095 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
1096 err_printk(ref->dev, NULL,
1097 "DMA-API: device driver tries to free an "
1098 "invalid DMA memory address\n");
1099 } else {
1100 err_printk(ref->dev, NULL,
1101 "DMA-API: device driver tries to free DMA "
1102 "memory it has not allocated [device "
1103 "address=0x%016llx] [size=%llu bytes]\n",
1104 ref->dev_addr, ref->size);
1105 }
1106 return;
1107 }
1108
1109 if (ref->size != entry->size) {
1110 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1111 "DMA memory with different size "
1112 "[device address=0x%016llx] [map size=%llu bytes] "
1113 "[unmap size=%llu bytes]\n",
1114 ref->dev_addr, entry->size, ref->size);
1115 }
1116
1117 if (ref->type != entry->type) {
1118 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1119 "DMA memory with wrong function "
1120 "[device address=0x%016llx] [size=%llu bytes] "
1121 "[mapped as %s] [unmapped as %s]\n",
1122 ref->dev_addr, ref->size,
1123 type2name[entry->type], type2name[ref->type]);
1124 } else if ((entry->type == dma_debug_coherent) &&
1125 (phys_addr(ref) != phys_addr(entry))) {
1126 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1127 "DMA memory with different CPU address "
1128 "[device address=0x%016llx] [size=%llu bytes] "
1129 "[cpu alloc address=0x%016llx] "
1130 "[cpu free address=0x%016llx]",
1131 ref->dev_addr, ref->size,
1132 phys_addr(entry),
1133 phys_addr(ref));
1134 }
1135
1136 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1137 ref->sg_call_ents != entry->sg_call_ents) {
1138 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1139 "DMA sg list with different entry count "
1140 "[map count=%d] [unmap count=%d]\n",
1141 entry->sg_call_ents, ref->sg_call_ents);
1142 }
1143
1144 /*
1145 * This may be no bug in reality - but most implementations of the
1146 * DMA API don't handle this properly, so check for it here
1147 */
1148 if (ref->direction != entry->direction) {
1149 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1150 "DMA memory with different direction "
1151 "[device address=0x%016llx] [size=%llu bytes] "
1152 "[mapped with %s] [unmapped with %s]\n",
1153 ref->dev_addr, ref->size,
1154 dir2name[entry->direction],
1155 dir2name[ref->direction]);
1156 }
1157
1158 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1159 err_printk(ref->dev, entry,
1160 "DMA-API: device driver failed to check map error"
1161 "[device address=0x%016llx] [size=%llu bytes] "
1162 "[mapped as %s]",
1163 ref->dev_addr, ref->size,
1164 type2name[entry->type]);
1165 }
1166
1167 hash_bucket_del(entry);
1168 dma_entry_free(entry);
1169
1170 put_hash_bucket(bucket, &flags);
1171}
1172
1173static void check_for_stack(struct device *dev,
1174 struct page *page, size_t offset)
1175{
1176 void *addr;
1177 struct vm_struct *stack_vm_area = task_stack_vm_area(current);
1178
1179 if (!stack_vm_area) {
1180 /* Stack is direct-mapped. */
1181 if (PageHighMem(page))
1182 return;
1183 addr = page_address(page) + offset;
1184 if (object_is_on_stack(addr))
1185 err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [addr=%p]\n", addr);
1186 } else {
1187 /* Stack is vmalloced. */
1188 int i;
1189
1190 for (i = 0; i < stack_vm_area->nr_pages; i++) {
1191 if (page != stack_vm_area->pages[i])
1192 continue;
1193
1194 addr = (u8 *)current->stack + i * PAGE_SIZE + offset;
1195 err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [probable addr=%p]\n", addr);
1196 break;
1197 }
1198 }
1199}
1200
1201static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
1202{
1203 unsigned long a1 = (unsigned long)addr;
1204 unsigned long b1 = a1 + len;
1205 unsigned long a2 = (unsigned long)start;
1206 unsigned long b2 = (unsigned long)end;
1207
1208 return !(b1 <= a2 || a1 >= b2);
1209}
1210
1211static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1212{
1213 if (overlap(addr, len, _stext, _etext) ||
1214 overlap(addr, len, __start_rodata, __end_rodata))
1215 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1216}
1217
1218static void check_sync(struct device *dev,
1219 struct dma_debug_entry *ref,
1220 bool to_cpu)
1221{
1222 struct dma_debug_entry *entry;
1223 struct hash_bucket *bucket;
1224 unsigned long flags;
1225
1226 bucket = get_hash_bucket(ref, &flags);
1227
1228 entry = bucket_find_contain(&bucket, ref, &flags);
1229
1230 if (!entry) {
1231 err_printk(dev, NULL, "DMA-API: device driver tries "
1232 "to sync DMA memory it has not allocated "
1233 "[device address=0x%016llx] [size=%llu bytes]\n",
1234 (unsigned long long)ref->dev_addr, ref->size);
1235 goto out;
1236 }
1237
1238 if (ref->size > entry->size) {
1239 err_printk(dev, entry, "DMA-API: device driver syncs"
1240 " DMA memory outside allocated range "
1241 "[device address=0x%016llx] "
1242 "[allocation size=%llu bytes] "
1243 "[sync offset+size=%llu]\n",
1244 entry->dev_addr, entry->size,
1245 ref->size);
1246 }
1247
1248 if (entry->direction == DMA_BIDIRECTIONAL)
1249 goto out;
1250
1251 if (ref->direction != entry->direction) {
1252 err_printk(dev, entry, "DMA-API: device driver syncs "
1253 "DMA memory with different direction "
1254 "[device address=0x%016llx] [size=%llu bytes] "
1255 "[mapped with %s] [synced with %s]\n",
1256 (unsigned long long)ref->dev_addr, entry->size,
1257 dir2name[entry->direction],
1258 dir2name[ref->direction]);
1259 }
1260
1261 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1262 !(ref->direction == DMA_TO_DEVICE))
1263 err_printk(dev, entry, "DMA-API: device driver syncs "
1264 "device read-only DMA memory for cpu "
1265 "[device address=0x%016llx] [size=%llu bytes] "
1266 "[mapped with %s] [synced with %s]\n",
1267 (unsigned long long)ref->dev_addr, entry->size,
1268 dir2name[entry->direction],
1269 dir2name[ref->direction]);
1270
1271 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1272 !(ref->direction == DMA_FROM_DEVICE))
1273 err_printk(dev, entry, "DMA-API: device driver syncs "
1274 "device write-only DMA memory to device "
1275 "[device address=0x%016llx] [size=%llu bytes] "
1276 "[mapped with %s] [synced with %s]\n",
1277 (unsigned long long)ref->dev_addr, entry->size,
1278 dir2name[entry->direction],
1279 dir2name[ref->direction]);
1280
1281 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1282 ref->sg_call_ents != entry->sg_call_ents) {
1283 err_printk(ref->dev, entry, "DMA-API: device driver syncs "
1284 "DMA sg list with different entry count "
1285 "[map count=%d] [sync count=%d]\n",
1286 entry->sg_call_ents, ref->sg_call_ents);
1287 }
1288
1289out:
1290 put_hash_bucket(bucket, &flags);
1291}
1292
1293void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1294 size_t size, int direction, dma_addr_t dma_addr,
1295 bool map_single)
1296{
1297 struct dma_debug_entry *entry;
1298
1299 if (unlikely(dma_debug_disabled()))
1300 return;
1301
1302 if (dma_mapping_error(dev, dma_addr))
1303 return;
1304
1305 entry = dma_entry_alloc();
1306 if (!entry)
1307 return;
1308
1309 entry->dev = dev;
1310 entry->type = dma_debug_page;
1311 entry->pfn = page_to_pfn(page);
1312 entry->offset = offset,
1313 entry->dev_addr = dma_addr;
1314 entry->size = size;
1315 entry->direction = direction;
1316 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1317
1318 if (map_single)
1319 entry->type = dma_debug_single;
1320
1321 check_for_stack(dev, page, offset);
1322
1323 if (!PageHighMem(page)) {
1324 void *addr = page_address(page) + offset;
1325
1326 check_for_illegal_area(dev, addr, size);
1327 }
1328
1329 add_dma_entry(entry);
1330}
1331EXPORT_SYMBOL(debug_dma_map_page);
1332
1333void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1334{
1335 struct dma_debug_entry ref;
1336 struct dma_debug_entry *entry;
1337 struct hash_bucket *bucket;
1338 unsigned long flags;
1339
1340 if (unlikely(dma_debug_disabled()))
1341 return;
1342
1343 ref.dev = dev;
1344 ref.dev_addr = dma_addr;
1345 bucket = get_hash_bucket(&ref, &flags);
1346
1347 list_for_each_entry(entry, &bucket->list, list) {
1348 if (!exact_match(&ref, entry))
1349 continue;
1350
1351 /*
1352 * The same physical address can be mapped multiple
1353 * times. Without a hardware IOMMU this results in the
1354 * same device addresses being put into the dma-debug
1355 * hash multiple times too. This can result in false
1356 * positives being reported. Therefore we implement a
1357 * best-fit algorithm here which updates the first entry
1358 * from the hash which fits the reference value and is
1359 * not currently listed as being checked.
1360 */
1361 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1362 entry->map_err_type = MAP_ERR_CHECKED;
1363 break;
1364 }
1365 }
1366
1367 put_hash_bucket(bucket, &flags);
1368}
1369EXPORT_SYMBOL(debug_dma_mapping_error);
1370
1371void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1372 size_t size, int direction, bool map_single)
1373{
1374 struct dma_debug_entry ref = {
1375 .type = dma_debug_page,
1376 .dev = dev,
1377 .dev_addr = addr,
1378 .size = size,
1379 .direction = direction,
1380 };
1381
1382 if (unlikely(dma_debug_disabled()))
1383 return;
1384
1385 if (map_single)
1386 ref.type = dma_debug_single;
1387
1388 check_unmap(&ref);
1389}
1390EXPORT_SYMBOL(debug_dma_unmap_page);
1391
1392void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1393 int nents, int mapped_ents, int direction)
1394{
1395 struct dma_debug_entry *entry;
1396 struct scatterlist *s;
1397 int i;
1398
1399 if (unlikely(dma_debug_disabled()))
1400 return;
1401
1402 for_each_sg(sg, s, mapped_ents, i) {
1403 entry = dma_entry_alloc();
1404 if (!entry)
1405 return;
1406
1407 entry->type = dma_debug_sg;
1408 entry->dev = dev;
1409 entry->pfn = page_to_pfn(sg_page(s));
1410 entry->offset = s->offset,
1411 entry->size = sg_dma_len(s);
1412 entry->dev_addr = sg_dma_address(s);
1413 entry->direction = direction;
1414 entry->sg_call_ents = nents;
1415 entry->sg_mapped_ents = mapped_ents;
1416
1417 check_for_stack(dev, sg_page(s), s->offset);
1418
1419 if (!PageHighMem(sg_page(s))) {
1420 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1421 }
1422
1423 add_dma_entry(entry);
1424 }
1425}
1426EXPORT_SYMBOL(debug_dma_map_sg);
1427
1428static int get_nr_mapped_entries(struct device *dev,
1429 struct dma_debug_entry *ref)
1430{
1431 struct dma_debug_entry *entry;
1432 struct hash_bucket *bucket;
1433 unsigned long flags;
1434 int mapped_ents;
1435
1436 bucket = get_hash_bucket(ref, &flags);
1437 entry = bucket_find_exact(bucket, ref);
1438 mapped_ents = 0;
1439
1440 if (entry)
1441 mapped_ents = entry->sg_mapped_ents;
1442 put_hash_bucket(bucket, &flags);
1443
1444 return mapped_ents;
1445}
1446
1447void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1448 int nelems, int dir)
1449{
1450 struct scatterlist *s;
1451 int mapped_ents = 0, i;
1452
1453 if (unlikely(dma_debug_disabled()))
1454 return;
1455
1456 for_each_sg(sglist, s, nelems, i) {
1457
1458 struct dma_debug_entry ref = {
1459 .type = dma_debug_sg,
1460 .dev = dev,
1461 .pfn = page_to_pfn(sg_page(s)),
1462 .offset = s->offset,
1463 .dev_addr = sg_dma_address(s),
1464 .size = sg_dma_len(s),
1465 .direction = dir,
1466 .sg_call_ents = nelems,
1467 };
1468
1469 if (mapped_ents && i >= mapped_ents)
1470 break;
1471
1472 if (!i)
1473 mapped_ents = get_nr_mapped_entries(dev, &ref);
1474
1475 check_unmap(&ref);
1476 }
1477}
1478EXPORT_SYMBOL(debug_dma_unmap_sg);
1479
1480void debug_dma_alloc_coherent(struct device *dev, size_t size,
1481 dma_addr_t dma_addr, void *virt)
1482{
1483 struct dma_debug_entry *entry;
1484
1485 if (unlikely(dma_debug_disabled()))
1486 return;
1487
1488 if (unlikely(virt == NULL))
1489 return;
1490
1491 entry = dma_entry_alloc();
1492 if (!entry)
1493 return;
1494
1495 entry->type = dma_debug_coherent;
1496 entry->dev = dev;
1497 entry->pfn = page_to_pfn(virt_to_page(virt));
1498 entry->offset = (size_t) virt & ~PAGE_MASK;
1499 entry->size = size;
1500 entry->dev_addr = dma_addr;
1501 entry->direction = DMA_BIDIRECTIONAL;
1502
1503 add_dma_entry(entry);
1504}
1505EXPORT_SYMBOL(debug_dma_alloc_coherent);
1506
1507void debug_dma_free_coherent(struct device *dev, size_t size,
1508 void *virt, dma_addr_t addr)
1509{
1510 struct dma_debug_entry ref = {
1511 .type = dma_debug_coherent,
1512 .dev = dev,
1513 .pfn = page_to_pfn(virt_to_page(virt)),
1514 .offset = (size_t) virt & ~PAGE_MASK,
1515 .dev_addr = addr,
1516 .size = size,
1517 .direction = DMA_BIDIRECTIONAL,
1518 };
1519
1520 if (unlikely(dma_debug_disabled()))
1521 return;
1522
1523 check_unmap(&ref);
1524}
1525EXPORT_SYMBOL(debug_dma_free_coherent);
1526
1527void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
1528 int direction, dma_addr_t dma_addr)
1529{
1530 struct dma_debug_entry *entry;
1531
1532 if (unlikely(dma_debug_disabled()))
1533 return;
1534
1535 entry = dma_entry_alloc();
1536 if (!entry)
1537 return;
1538
1539 entry->type = dma_debug_resource;
1540 entry->dev = dev;
1541 entry->pfn = PHYS_PFN(addr);
1542 entry->offset = offset_in_page(addr);
1543 entry->size = size;
1544 entry->dev_addr = dma_addr;
1545 entry->direction = direction;
1546 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1547
1548 add_dma_entry(entry);
1549}
1550EXPORT_SYMBOL(debug_dma_map_resource);
1551
1552void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
1553 size_t size, int direction)
1554{
1555 struct dma_debug_entry ref = {
1556 .type = dma_debug_resource,
1557 .dev = dev,
1558 .dev_addr = dma_addr,
1559 .size = size,
1560 .direction = direction,
1561 };
1562
1563 if (unlikely(dma_debug_disabled()))
1564 return;
1565
1566 check_unmap(&ref);
1567}
1568EXPORT_SYMBOL(debug_dma_unmap_resource);
1569
1570void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1571 size_t size, int direction)
1572{
1573 struct dma_debug_entry ref;
1574
1575 if (unlikely(dma_debug_disabled()))
1576 return;
1577
1578 ref.type = dma_debug_single;
1579 ref.dev = dev;
1580 ref.dev_addr = dma_handle;
1581 ref.size = size;
1582 ref.direction = direction;
1583 ref.sg_call_ents = 0;
1584
1585 check_sync(dev, &ref, true);
1586}
1587EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1588
1589void debug_dma_sync_single_for_device(struct device *dev,
1590 dma_addr_t dma_handle, size_t size,
1591 int direction)
1592{
1593 struct dma_debug_entry ref;
1594
1595 if (unlikely(dma_debug_disabled()))
1596 return;
1597
1598 ref.type = dma_debug_single;
1599 ref.dev = dev;
1600 ref.dev_addr = dma_handle;
1601 ref.size = size;
1602 ref.direction = direction;
1603 ref.sg_call_ents = 0;
1604
1605 check_sync(dev, &ref, false);
1606}
1607EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1608
1609void debug_dma_sync_single_range_for_cpu(struct device *dev,
1610 dma_addr_t dma_handle,
1611 unsigned long offset, size_t size,
1612 int direction)
1613{
1614 struct dma_debug_entry ref;
1615
1616 if (unlikely(dma_debug_disabled()))
1617 return;
1618
1619 ref.type = dma_debug_single;
1620 ref.dev = dev;
1621 ref.dev_addr = dma_handle;
1622 ref.size = offset + size;
1623 ref.direction = direction;
1624 ref.sg_call_ents = 0;
1625
1626 check_sync(dev, &ref, true);
1627}
1628EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1629
1630void debug_dma_sync_single_range_for_device(struct device *dev,
1631 dma_addr_t dma_handle,
1632 unsigned long offset,
1633 size_t size, int direction)
1634{
1635 struct dma_debug_entry ref;
1636
1637 if (unlikely(dma_debug_disabled()))
1638 return;
1639
1640 ref.type = dma_debug_single;
1641 ref.dev = dev;
1642 ref.dev_addr = dma_handle;
1643 ref.size = offset + size;
1644 ref.direction = direction;
1645 ref.sg_call_ents = 0;
1646
1647 check_sync(dev, &ref, false);
1648}
1649EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1650
1651void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1652 int nelems, int direction)
1653{
1654 struct scatterlist *s;
1655 int mapped_ents = 0, i;
1656
1657 if (unlikely(dma_debug_disabled()))
1658 return;
1659
1660 for_each_sg(sg, s, nelems, i) {
1661
1662 struct dma_debug_entry ref = {
1663 .type = dma_debug_sg,
1664 .dev = dev,
1665 .pfn = page_to_pfn(sg_page(s)),
1666 .offset = s->offset,
1667 .dev_addr = sg_dma_address(s),
1668 .size = sg_dma_len(s),
1669 .direction = direction,
1670 .sg_call_ents = nelems,
1671 };
1672
1673 if (!i)
1674 mapped_ents = get_nr_mapped_entries(dev, &ref);
1675
1676 if (i >= mapped_ents)
1677 break;
1678
1679 check_sync(dev, &ref, true);
1680 }
1681}
1682EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1683
1684void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1685 int nelems, int direction)
1686{
1687 struct scatterlist *s;
1688 int mapped_ents = 0, i;
1689
1690 if (unlikely(dma_debug_disabled()))
1691 return;
1692
1693 for_each_sg(sg, s, nelems, i) {
1694
1695 struct dma_debug_entry ref = {
1696 .type = dma_debug_sg,
1697 .dev = dev,
1698 .pfn = page_to_pfn(sg_page(s)),
1699 .offset = s->offset,
1700 .dev_addr = sg_dma_address(s),
1701 .size = sg_dma_len(s),
1702 .direction = direction,
1703 .sg_call_ents = nelems,
1704 };
1705 if (!i)
1706 mapped_ents = get_nr_mapped_entries(dev, &ref);
1707
1708 if (i >= mapped_ents)
1709 break;
1710
1711 check_sync(dev, &ref, false);
1712 }
1713}
1714EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1715
1716static int __init dma_debug_driver_setup(char *str)
1717{
1718 int i;
1719
1720 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1721 current_driver_name[i] = *str;
1722 if (*str == 0)
1723 break;
1724 }
1725
1726 if (current_driver_name[0])
1727 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1728 current_driver_name);
1729
1730
1731 return 1;
1732}
1733__setup("dma_debug_driver=", dma_debug_driver_setup);