projects/linux·blob v4.0-rc2 · refs

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1/*
2 * Copyright (C) 2008 Advanced Micro Devices, Inc.
3 *
4 * Author: Joerg Roedel <[email protected]>
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/uaccess.h>
27#include <linux/export.h>
28#include <linux/device.h>
29#include <linux/types.h>
30#include <linux/sched.h>
31#include <linux/ctype.h>
32#include <linux/list.h>
33#include <linux/slab.h>
34
35#include <asm/sections.h>
36
37#define HASH_SIZE 1024ULL
38#define HASH_FN_SHIFT 13
39#define HASH_FN_MASK (HASH_SIZE - 1)
40
41enum {
42 dma_debug_single,
43 dma_debug_page,
44 dma_debug_sg,
45 dma_debug_coherent,
46};
47
48enum map_err_types {
49 MAP_ERR_CHECK_NOT_APPLICABLE,
50 MAP_ERR_NOT_CHECKED,
51 MAP_ERR_CHECKED,
52};
53
54#define DMA_DEBUG_STACKTRACE_ENTRIES 5
55
56/**
57 * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
58 * @list: node on pre-allocated free_entries list
59 * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
60 * @type: single, page, sg, coherent
61 * @pfn: page frame of the start address
62 * @offset: offset of mapping relative to pfn
63 * @size: length of the mapping
64 * @direction: enum dma_data_direction
65 * @sg_call_ents: 'nents' from dma_map_sg
66 * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
67 * @map_err_type: track whether dma_mapping_error() was checked
68 * @stacktrace: support backtraces when a violation is detected
69 */
70struct dma_debug_entry {
71 struct list_head list;
72 struct device *dev;
73 int type;
74 unsigned long pfn;
75 size_t offset;
76 u64 dev_addr;
77 u64 size;
78 int direction;
79 int sg_call_ents;
80 int sg_mapped_ents;
81 enum map_err_types map_err_type;
82#ifdef CONFIG_STACKTRACE
83 struct stack_trace stacktrace;
84 unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
85#endif
86};
87
88typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
89
90struct hash_bucket {
91 struct list_head list;
92 spinlock_t lock;
93} ____cacheline_aligned_in_smp;
94
95/* Hash list to save the allocated dma addresses */
96static struct hash_bucket dma_entry_hash[HASH_SIZE];
97/* List of pre-allocated dma_debug_entry's */
98static LIST_HEAD(free_entries);
99/* Lock for the list above */
100static DEFINE_SPINLOCK(free_entries_lock);
101
102/* Global disable flag - will be set in case of an error */
103static u32 global_disable __read_mostly;
104
105/* Early initialization disable flag, set at the end of dma_debug_init */
106static bool dma_debug_initialized __read_mostly;
107
108static inline bool dma_debug_disabled(void)
109{
110 return global_disable || !dma_debug_initialized;
111}
112
113/* Global error count */
114static u32 error_count;
115
116/* Global error show enable*/
117static u32 show_all_errors __read_mostly;
118/* Number of errors to show */
119static u32 show_num_errors = 1;
120
121static u32 num_free_entries;
122static u32 min_free_entries;
123static u32 nr_total_entries;
124
125/* number of preallocated entries requested by kernel cmdline */
126static u32 req_entries;
127
128/* debugfs dentry's for the stuff above */
129static struct dentry *dma_debug_dent __read_mostly;
130static struct dentry *global_disable_dent __read_mostly;
131static struct dentry *error_count_dent __read_mostly;
132static struct dentry *show_all_errors_dent __read_mostly;
133static struct dentry *show_num_errors_dent __read_mostly;
134static struct dentry *num_free_entries_dent __read_mostly;
135static struct dentry *min_free_entries_dent __read_mostly;
136static struct dentry *filter_dent __read_mostly;
137
138/* per-driver filter related state */
139
140#define NAME_MAX_LEN 64
141
142static char current_driver_name[NAME_MAX_LEN] __read_mostly;
143static struct device_driver *current_driver __read_mostly;
144
145static DEFINE_RWLOCK(driver_name_lock);
146
147static const char *const maperr2str[] = {
148 [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
149 [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
150 [MAP_ERR_CHECKED] = "dma map error checked",
151};
152
153static const char *type2name[4] = { "single", "page",
154 "scather-gather", "coherent" };
155
156static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
157 "DMA_FROM_DEVICE", "DMA_NONE" };
158
159/*
160 * The access to some variables in this macro is racy. We can't use atomic_t
161 * here because all these variables are exported to debugfs. Some of them even
162 * writeable. This is also the reason why a lock won't help much. But anyway,
163 * the races are no big deal. Here is why:
164 *
165 * error_count: the addition is racy, but the worst thing that can happen is
166 * that we don't count some errors
167 * show_num_errors: the subtraction is racy. Also no big deal because in
168 * worst case this will result in one warning more in the
169 * system log than the user configured. This variable is
170 * writeable via debugfs.
171 */
172static inline void dump_entry_trace(struct dma_debug_entry *entry)
173{
174#ifdef CONFIG_STACKTRACE
175 if (entry) {
176 pr_warning("Mapped at:\n");
177 print_stack_trace(&entry->stacktrace, 0);
178 }
179#endif
180}
181
182static bool driver_filter(struct device *dev)
183{
184 struct device_driver *drv;
185 unsigned long flags;
186 bool ret;
187
188 /* driver filter off */
189 if (likely(!current_driver_name[0]))
190 return true;
191
192 /* driver filter on and initialized */
193 if (current_driver && dev && dev->driver == current_driver)
194 return true;
195
196 /* driver filter on, but we can't filter on a NULL device... */
197 if (!dev)
198 return false;
199
200 if (current_driver || !current_driver_name[0])
201 return false;
202
203 /* driver filter on but not yet initialized */
204 drv = dev->driver;
205 if (!drv)
206 return false;
207
208 /* lock to protect against change of current_driver_name */
209 read_lock_irqsave(&driver_name_lock, flags);
210
211 ret = false;
212 if (drv->name &&
213 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
214 current_driver = drv;
215 ret = true;
216 }
217
218 read_unlock_irqrestore(&driver_name_lock, flags);
219
220 return ret;
221}
222
223#define err_printk(dev, entry, format, arg...) do { \
224 error_count += 1; \
225 if (driver_filter(dev) && \
226 (show_all_errors || show_num_errors > 0)) { \
227 WARN(1, "%s %s: " format, \
228 dev ? dev_driver_string(dev) : "NULL", \
229 dev ? dev_name(dev) : "NULL", ## arg); \
230 dump_entry_trace(entry); \
231 } \
232 if (!show_all_errors && show_num_errors > 0) \
233 show_num_errors -= 1; \
234 } while (0);
235
236/*
237 * Hash related functions
238 *
239 * Every DMA-API request is saved into a struct dma_debug_entry. To
240 * have quick access to these structs they are stored into a hash.
241 */
242static int hash_fn(struct dma_debug_entry *entry)
243{
244 /*
245 * Hash function is based on the dma address.
246 * We use bits 20-27 here as the index into the hash
247 */
248 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
249}
250
251/*
252 * Request exclusive access to a hash bucket for a given dma_debug_entry.
253 */
254static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
255 unsigned long *flags)
256{
257 int idx = hash_fn(entry);
258 unsigned long __flags;
259
260 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
261 *flags = __flags;
262 return &dma_entry_hash[idx];
263}
264
265/*
266 * Give up exclusive access to the hash bucket
267 */
268static void put_hash_bucket(struct hash_bucket *bucket,
269 unsigned long *flags)
270{
271 unsigned long __flags = *flags;
272
273 spin_unlock_irqrestore(&bucket->lock, __flags);
274}
275
276static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
277{
278 return ((a->dev_addr == b->dev_addr) &&
279 (a->dev == b->dev)) ? true : false;
280}
281
282static bool containing_match(struct dma_debug_entry *a,
283 struct dma_debug_entry *b)
284{
285 if (a->dev != b->dev)
286 return false;
287
288 if ((b->dev_addr <= a->dev_addr) &&
289 ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
290 return true;
291
292 return false;
293}
294
295/*
296 * Search a given entry in the hash bucket list
297 */
298static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
299 struct dma_debug_entry *ref,
300 match_fn match)
301{
302 struct dma_debug_entry *entry, *ret = NULL;
303 int matches = 0, match_lvl, last_lvl = -1;
304
305 list_for_each_entry(entry, &bucket->list, list) {
306 if (!match(ref, entry))
307 continue;
308
309 /*
310 * Some drivers map the same physical address multiple
311 * times. Without a hardware IOMMU this results in the
312 * same device addresses being put into the dma-debug
313 * hash multiple times too. This can result in false
314 * positives being reported. Therefore we implement a
315 * best-fit algorithm here which returns the entry from
316 * the hash which fits best to the reference value
317 * instead of the first-fit.
318 */
319 matches += 1;
320 match_lvl = 0;
321 entry->size == ref->size ? ++match_lvl : 0;
322 entry->type == ref->type ? ++match_lvl : 0;
323 entry->direction == ref->direction ? ++match_lvl : 0;
324 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
325
326 if (match_lvl == 4) {
327 /* perfect-fit - return the result */
328 return entry;
329 } else if (match_lvl > last_lvl) {
330 /*
331 * We found an entry that fits better then the
332 * previous one or it is the 1st match.
333 */
334 last_lvl = match_lvl;
335 ret = entry;
336 }
337 }
338
339 /*
340 * If we have multiple matches but no perfect-fit, just return
341 * NULL.
342 */
343 ret = (matches == 1) ? ret : NULL;
344
345 return ret;
346}
347
348static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
349 struct dma_debug_entry *ref)
350{
351 return __hash_bucket_find(bucket, ref, exact_match);
352}
353
354static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
355 struct dma_debug_entry *ref,
356 unsigned long *flags)
357{
358
359 unsigned int max_range = dma_get_max_seg_size(ref->dev);
360 struct dma_debug_entry *entry, index = *ref;
361 unsigned int range = 0;
362
363 while (range <= max_range) {
364 entry = __hash_bucket_find(*bucket, &index, containing_match);
365
366 if (entry)
367 return entry;
368
369 /*
370 * Nothing found, go back a hash bucket
371 */
372 put_hash_bucket(*bucket, flags);
373 range += (1 << HASH_FN_SHIFT);
374 index.dev_addr -= (1 << HASH_FN_SHIFT);
375 *bucket = get_hash_bucket(&index, flags);
376 }
377
378 return NULL;
379}
380
381/*
382 * Add an entry to a hash bucket
383 */
384static void hash_bucket_add(struct hash_bucket *bucket,
385 struct dma_debug_entry *entry)
386{
387 list_add_tail(&entry->list, &bucket->list);
388}
389
390/*
391 * Remove entry from a hash bucket list
392 */
393static void hash_bucket_del(struct dma_debug_entry *entry)
394{
395 list_del(&entry->list);
396}
397
398static unsigned long long phys_addr(struct dma_debug_entry *entry)
399{
400 return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
401}
402
403/*
404 * Dump mapping entries for debugging purposes
405 */
406void debug_dma_dump_mappings(struct device *dev)
407{
408 int idx;
409
410 for (idx = 0; idx < HASH_SIZE; idx++) {
411 struct hash_bucket *bucket = &dma_entry_hash[idx];
412 struct dma_debug_entry *entry;
413 unsigned long flags;
414
415 spin_lock_irqsave(&bucket->lock, flags);
416
417 list_for_each_entry(entry, &bucket->list, list) {
418 if (!dev || dev == entry->dev) {
419 dev_info(entry->dev,
420 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
421 type2name[entry->type], idx,
422 phys_addr(entry), entry->pfn,
423 entry->dev_addr, entry->size,
424 dir2name[entry->direction],
425 maperr2str[entry->map_err_type]);
426 }
427 }
428
429 spin_unlock_irqrestore(&bucket->lock, flags);
430 }
431}
432EXPORT_SYMBOL(debug_dma_dump_mappings);
433
434/*
435 * For each mapping (initial cacheline in the case of
436 * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
437 * scatterlist, or the cacheline specified in dma_map_single) insert
438 * into this tree using the cacheline as the key. At
439 * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If
440 * the entry already exists at insertion time add a tag as a reference
441 * count for the overlapping mappings. For now, the overlap tracking
442 * just ensures that 'unmaps' balance 'maps' before marking the
443 * cacheline idle, but we should also be flagging overlaps as an API
444 * violation.
445 *
446 * Memory usage is mostly constrained by the maximum number of available
447 * dma-debug entries in that we need a free dma_debug_entry before
448 * inserting into the tree. In the case of dma_map_page and
449 * dma_alloc_coherent there is only one dma_debug_entry and one
450 * dma_active_cacheline entry to track per event. dma_map_sg(), on the
451 * other hand, consumes a single dma_debug_entry, but inserts 'nents'
452 * entries into the tree.
453 *
454 * At any time debug_dma_assert_idle() can be called to trigger a
455 * warning if any cachelines in the given page are in the active set.
456 */
457static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
458static DEFINE_SPINLOCK(radix_lock);
459#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
460#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
461#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
462
463static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
464{
465 return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
466 (entry->offset >> L1_CACHE_SHIFT);
467}
468
469static int active_cacheline_read_overlap(phys_addr_t cln)
470{
471 int overlap = 0, i;
472
473 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
474 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
475 overlap |= 1 << i;
476 return overlap;
477}
478
479static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
480{
481 int i;
482
483 if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
484 return overlap;
485
486 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
487 if (overlap & 1 << i)
488 radix_tree_tag_set(&dma_active_cacheline, cln, i);
489 else
490 radix_tree_tag_clear(&dma_active_cacheline, cln, i);
491
492 return overlap;
493}
494
495static void active_cacheline_inc_overlap(phys_addr_t cln)
496{
497 int overlap = active_cacheline_read_overlap(cln);
498
499 overlap = active_cacheline_set_overlap(cln, ++overlap);
500
501 /* If we overflowed the overlap counter then we're potentially
502 * leaking dma-mappings. Otherwise, if maps and unmaps are
503 * balanced then this overflow may cause false negatives in
504 * debug_dma_assert_idle() as the cacheline may be marked idle
505 * prematurely.
506 */
507 WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
508 "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
509 ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
510}
511
512static int active_cacheline_dec_overlap(phys_addr_t cln)
513{
514 int overlap = active_cacheline_read_overlap(cln);
515
516 return active_cacheline_set_overlap(cln, --overlap);
517}
518
519static int active_cacheline_insert(struct dma_debug_entry *entry)
520{
521 phys_addr_t cln = to_cacheline_number(entry);
522 unsigned long flags;
523 int rc;
524
525 /* If the device is not writing memory then we don't have any
526 * concerns about the cpu consuming stale data. This mitigates
527 * legitimate usages of overlapping mappings.
528 */
529 if (entry->direction == DMA_TO_DEVICE)
530 return 0;
531
532 spin_lock_irqsave(&radix_lock, flags);
533 rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
534 if (rc == -EEXIST)
535 active_cacheline_inc_overlap(cln);
536 spin_unlock_irqrestore(&radix_lock, flags);
537
538 return rc;
539}
540
541static void active_cacheline_remove(struct dma_debug_entry *entry)
542{
543 phys_addr_t cln = to_cacheline_number(entry);
544 unsigned long flags;
545
546 /* ...mirror the insert case */
547 if (entry->direction == DMA_TO_DEVICE)
548 return;
549
550 spin_lock_irqsave(&radix_lock, flags);
551 /* since we are counting overlaps the final put of the
552 * cacheline will occur when the overlap count is 0.
553 * active_cacheline_dec_overlap() returns -1 in that case
554 */
555 if (active_cacheline_dec_overlap(cln) < 0)
556 radix_tree_delete(&dma_active_cacheline, cln);
557 spin_unlock_irqrestore(&radix_lock, flags);
558}
559
560/**
561 * debug_dma_assert_idle() - assert that a page is not undergoing dma
562 * @page: page to lookup in the dma_active_cacheline tree
563 *
564 * Place a call to this routine in cases where the cpu touching the page
565 * before the dma completes (page is dma_unmapped) will lead to data
566 * corruption.
567 */
568void debug_dma_assert_idle(struct page *page)
569{
570 static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
571 struct dma_debug_entry *entry = NULL;
572 void **results = (void **) &ents;
573 unsigned int nents, i;
574 unsigned long flags;
575 phys_addr_t cln;
576
577 if (!page)
578 return;
579
580 cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
581 spin_lock_irqsave(&radix_lock, flags);
582 nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
583 CACHELINES_PER_PAGE);
584 for (i = 0; i < nents; i++) {
585 phys_addr_t ent_cln = to_cacheline_number(ents[i]);
586
587 if (ent_cln == cln) {
588 entry = ents[i];
589 break;
590 } else if (ent_cln >= cln + CACHELINES_PER_PAGE)
591 break;
592 }
593 spin_unlock_irqrestore(&radix_lock, flags);
594
595 if (!entry)
596 return;
597
598 cln = to_cacheline_number(entry);
599 err_printk(entry->dev, entry,
600 "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
601 &cln);
602}
603
604/*
605 * Wrapper function for adding an entry to the hash.
606 * This function takes care of locking itself.
607 */
608static void add_dma_entry(struct dma_debug_entry *entry)
609{
610 struct hash_bucket *bucket;
611 unsigned long flags;
612 int rc;
613
614 bucket = get_hash_bucket(entry, &flags);
615 hash_bucket_add(bucket, entry);
616 put_hash_bucket(bucket, &flags);
617
618 rc = active_cacheline_insert(entry);
619 if (rc == -ENOMEM) {
620 pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
621 global_disable = true;
622 }
623
624 /* TODO: report -EEXIST errors here as overlapping mappings are
625 * not supported by the DMA API
626 */
627}
628
629static struct dma_debug_entry *__dma_entry_alloc(void)
630{
631 struct dma_debug_entry *entry;
632
633 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
634 list_del(&entry->list);
635 memset(entry, 0, sizeof(*entry));
636
637 num_free_entries -= 1;
638 if (num_free_entries < min_free_entries)
639 min_free_entries = num_free_entries;
640
641 return entry;
642}
643
644/* struct dma_entry allocator
645 *
646 * The next two functions implement the allocator for
647 * struct dma_debug_entries.
648 */
649static struct dma_debug_entry *dma_entry_alloc(void)
650{
651 struct dma_debug_entry *entry;
652 unsigned long flags;
653
654 spin_lock_irqsave(&free_entries_lock, flags);
655
656 if (list_empty(&free_entries)) {
657 pr_err("DMA-API: debugging out of memory - disabling\n");
658 global_disable = true;
659 spin_unlock_irqrestore(&free_entries_lock, flags);
660 return NULL;
661 }
662
663 entry = __dma_entry_alloc();
664
665 spin_unlock_irqrestore(&free_entries_lock, flags);
666
667#ifdef CONFIG_STACKTRACE
668 entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
669 entry->stacktrace.entries = entry->st_entries;
670 entry->stacktrace.skip = 2;
671 save_stack_trace(&entry->stacktrace);
672#endif
673
674 return entry;
675}
676
677static void dma_entry_free(struct dma_debug_entry *entry)
678{
679 unsigned long flags;
680
681 active_cacheline_remove(entry);
682
683 /*
684 * add to beginning of the list - this way the entries are
685 * more likely cache hot when they are reallocated.
686 */
687 spin_lock_irqsave(&free_entries_lock, flags);
688 list_add(&entry->list, &free_entries);
689 num_free_entries += 1;
690 spin_unlock_irqrestore(&free_entries_lock, flags);
691}
692
693int dma_debug_resize_entries(u32 num_entries)
694{
695 int i, delta, ret = 0;
696 unsigned long flags;
697 struct dma_debug_entry *entry;
698 LIST_HEAD(tmp);
699
700 spin_lock_irqsave(&free_entries_lock, flags);
701
702 if (nr_total_entries < num_entries) {
703 delta = num_entries - nr_total_entries;
704
705 spin_unlock_irqrestore(&free_entries_lock, flags);
706
707 for (i = 0; i < delta; i++) {
708 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
709 if (!entry)
710 break;
711
712 list_add_tail(&entry->list, &tmp);
713 }
714
715 spin_lock_irqsave(&free_entries_lock, flags);
716
717 list_splice(&tmp, &free_entries);
718 nr_total_entries += i;
719 num_free_entries += i;
720 } else {
721 delta = nr_total_entries - num_entries;
722
723 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
724 entry = __dma_entry_alloc();
725 kfree(entry);
726 }
727
728 nr_total_entries -= i;
729 }
730
731 if (nr_total_entries != num_entries)
732 ret = 1;
733
734 spin_unlock_irqrestore(&free_entries_lock, flags);
735
736 return ret;
737}
738EXPORT_SYMBOL(dma_debug_resize_entries);
739
740/*
741 * DMA-API debugging init code
742 *
743 * The init code does two things:
744 * 1. Initialize core data structures
745 * 2. Preallocate a given number of dma_debug_entry structs
746 */
747
748static int prealloc_memory(u32 num_entries)
749{
750 struct dma_debug_entry *entry, *next_entry;
751 int i;
752
753 for (i = 0; i < num_entries; ++i) {
754 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
755 if (!entry)
756 goto out_err;
757
758 list_add_tail(&entry->list, &free_entries);
759 }
760
761 num_free_entries = num_entries;
762 min_free_entries = num_entries;
763
764 pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
765
766 return 0;
767
768out_err:
769
770 list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
771 list_del(&entry->list);
772 kfree(entry);
773 }
774
775 return -ENOMEM;
776}
777
778static ssize_t filter_read(struct file *file, char __user *user_buf,
779 size_t count, loff_t *ppos)
780{
781 char buf[NAME_MAX_LEN + 1];
782 unsigned long flags;
783 int len;
784
785 if (!current_driver_name[0])
786 return 0;
787
788 /*
789 * We can't copy to userspace directly because current_driver_name can
790 * only be read under the driver_name_lock with irqs disabled. So
791 * create a temporary copy first.
792 */
793 read_lock_irqsave(&driver_name_lock, flags);
794 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
795 read_unlock_irqrestore(&driver_name_lock, flags);
796
797 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
798}
799
800static ssize_t filter_write(struct file *file, const char __user *userbuf,
801 size_t count, loff_t *ppos)
802{
803 char buf[NAME_MAX_LEN];
804 unsigned long flags;
805 size_t len;
806 int i;
807
808 /*
809 * We can't copy from userspace directly. Access to
810 * current_driver_name is protected with a write_lock with irqs
811 * disabled. Since copy_from_user can fault and may sleep we
812 * need to copy to temporary buffer first
813 */
814 len = min(count, (size_t)(NAME_MAX_LEN - 1));
815 if (copy_from_user(buf, userbuf, len))
816 return -EFAULT;
817
818 buf[len] = 0;
819
820 write_lock_irqsave(&driver_name_lock, flags);
821
822 /*
823 * Now handle the string we got from userspace very carefully.
824 * The rules are:
825 * - only use the first token we got
826 * - token delimiter is everything looking like a space
827 * character (' ', '\n', '\t' ...)
828 *
829 */
830 if (!isalnum(buf[0])) {
831 /*
832 * If the first character userspace gave us is not
833 * alphanumerical then assume the filter should be
834 * switched off.
835 */
836 if (current_driver_name[0])
837 pr_info("DMA-API: switching off dma-debug driver filter\n");
838 current_driver_name[0] = 0;
839 current_driver = NULL;
840 goto out_unlock;
841 }
842
843 /*
844 * Now parse out the first token and use it as the name for the
845 * driver to filter for.
846 */
847 for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
848 current_driver_name[i] = buf[i];
849 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
850 break;
851 }
852 current_driver_name[i] = 0;
853 current_driver = NULL;
854
855 pr_info("DMA-API: enable driver filter for driver [%s]\n",
856 current_driver_name);
857
858out_unlock:
859 write_unlock_irqrestore(&driver_name_lock, flags);
860
861 return count;
862}
863
864static const struct file_operations filter_fops = {
865 .read = filter_read,
866 .write = filter_write,
867 .llseek = default_llseek,
868};
869
870static int dma_debug_fs_init(void)
871{
872 dma_debug_dent = debugfs_create_dir("dma-api", NULL);
873 if (!dma_debug_dent) {
874 pr_err("DMA-API: can not create debugfs directory\n");
875 return -ENOMEM;
876 }
877
878 global_disable_dent = debugfs_create_bool("disabled", 0444,
879 dma_debug_dent,
880 &global_disable);
881 if (!global_disable_dent)
882 goto out_err;
883
884 error_count_dent = debugfs_create_u32("error_count", 0444,
885 dma_debug_dent, &error_count);
886 if (!error_count_dent)
887 goto out_err;
888
889 show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
890 dma_debug_dent,
891 &show_all_errors);
892 if (!show_all_errors_dent)
893 goto out_err;
894
895 show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
896 dma_debug_dent,
897 &show_num_errors);
898 if (!show_num_errors_dent)
899 goto out_err;
900
901 num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
902 dma_debug_dent,
903 &num_free_entries);
904 if (!num_free_entries_dent)
905 goto out_err;
906
907 min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
908 dma_debug_dent,
909 &min_free_entries);
910 if (!min_free_entries_dent)
911 goto out_err;
912
913 filter_dent = debugfs_create_file("driver_filter", 0644,
914 dma_debug_dent, NULL, &filter_fops);
915 if (!filter_dent)
916 goto out_err;
917
918 return 0;
919
920out_err:
921 debugfs_remove_recursive(dma_debug_dent);
922
923 return -ENOMEM;
924}
925
926static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
927{
928 struct dma_debug_entry *entry;
929 unsigned long flags;
930 int count = 0, i;
931
932 local_irq_save(flags);
933
934 for (i = 0; i < HASH_SIZE; ++i) {
935 spin_lock(&dma_entry_hash[i].lock);
936 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
937 if (entry->dev == dev) {
938 count += 1;
939 *out_entry = entry;
940 }
941 }
942 spin_unlock(&dma_entry_hash[i].lock);
943 }
944
945 local_irq_restore(flags);
946
947 return count;
948}
949
950static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
951{
952 struct device *dev = data;
953 struct dma_debug_entry *uninitialized_var(entry);
954 int count;
955
956 if (dma_debug_disabled())
957 return 0;
958
959 switch (action) {
960 case BUS_NOTIFY_UNBOUND_DRIVER:
961 count = device_dma_allocations(dev, &entry);
962 if (count == 0)
963 break;
964 err_printk(dev, entry, "DMA-API: device driver has pending "
965 "DMA allocations while released from device "
966 "[count=%d]\n"
967 "One of leaked entries details: "
968 "[device address=0x%016llx] [size=%llu bytes] "
969 "[mapped with %s] [mapped as %s]\n",
970 count, entry->dev_addr, entry->size,
971 dir2name[entry->direction], type2name[entry->type]);
972 break;
973 default:
974 break;
975 }
976
977 return 0;
978}
979
980void dma_debug_add_bus(struct bus_type *bus)
981{
982 struct notifier_block *nb;
983
984 if (dma_debug_disabled())
985 return;
986
987 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
988 if (nb == NULL) {
989 pr_err("dma_debug_add_bus: out of memory\n");
990 return;
991 }
992
993 nb->notifier_call = dma_debug_device_change;
994
995 bus_register_notifier(bus, nb);
996}
997
998/*
999 * Let the architectures decide how many entries should be preallocated.
1000 */
1001void dma_debug_init(u32 num_entries)
1002{
1003 int i;
1004
1005 /* Do not use dma_debug_initialized here, since we really want to be
1006 * called to set dma_debug_initialized
1007 */
1008 if (global_disable)
1009 return;
1010
1011 for (i = 0; i < HASH_SIZE; ++i) {
1012 INIT_LIST_HEAD(&dma_entry_hash[i].list);
1013 spin_lock_init(&dma_entry_hash[i].lock);
1014 }
1015
1016 if (dma_debug_fs_init() != 0) {
1017 pr_err("DMA-API: error creating debugfs entries - disabling\n");
1018 global_disable = true;
1019
1020 return;
1021 }
1022
1023 if (req_entries)
1024 num_entries = req_entries;
1025
1026 if (prealloc_memory(num_entries) != 0) {
1027 pr_err("DMA-API: debugging out of memory error - disabled\n");
1028 global_disable = true;
1029
1030 return;
1031 }
1032
1033 nr_total_entries = num_free_entries;
1034
1035 dma_debug_initialized = true;
1036
1037 pr_info("DMA-API: debugging enabled by kernel config\n");
1038}
1039
1040static __init int dma_debug_cmdline(char *str)
1041{
1042 if (!str)
1043 return -EINVAL;
1044
1045 if (strncmp(str, "off", 3) == 0) {
1046 pr_info("DMA-API: debugging disabled on kernel command line\n");
1047 global_disable = true;
1048 }
1049
1050 return 0;
1051}
1052
1053static __init int dma_debug_entries_cmdline(char *str)
1054{
1055 int res;
1056
1057 if (!str)
1058 return -EINVAL;
1059
1060 res = get_option(&str, &req_entries);
1061
1062 if (!res)
1063 req_entries = 0;
1064
1065 return 0;
1066}
1067
1068__setup("dma_debug=", dma_debug_cmdline);
1069__setup("dma_debug_entries=", dma_debug_entries_cmdline);
1070
1071static void check_unmap(struct dma_debug_entry *ref)
1072{
1073 struct dma_debug_entry *entry;
1074 struct hash_bucket *bucket;
1075 unsigned long flags;
1076
1077 bucket = get_hash_bucket(ref, &flags);
1078 entry = bucket_find_exact(bucket, ref);
1079
1080 if (!entry) {
1081 /* must drop lock before calling dma_mapping_error */
1082 put_hash_bucket(bucket, &flags);
1083
1084 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
1085 err_printk(ref->dev, NULL,
1086 "DMA-API: device driver tries to free an "
1087 "invalid DMA memory address\n");
1088 } else {
1089 err_printk(ref->dev, NULL,
1090 "DMA-API: device driver tries to free DMA "
1091 "memory it has not allocated [device "
1092 "address=0x%016llx] [size=%llu bytes]\n",
1093 ref->dev_addr, ref->size);
1094 }
1095 return;
1096 }
1097
1098 if (ref->size != entry->size) {
1099 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1100 "DMA memory with different size "
1101 "[device address=0x%016llx] [map size=%llu bytes] "
1102 "[unmap size=%llu bytes]\n",
1103 ref->dev_addr, entry->size, ref->size);
1104 }
1105
1106 if (ref->type != entry->type) {
1107 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1108 "DMA memory with wrong function "
1109 "[device address=0x%016llx] [size=%llu bytes] "
1110 "[mapped as %s] [unmapped as %s]\n",
1111 ref->dev_addr, ref->size,
1112 type2name[entry->type], type2name[ref->type]);
1113 } else if ((entry->type == dma_debug_coherent) &&
1114 (phys_addr(ref) != phys_addr(entry))) {
1115 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1116 "DMA memory with different CPU address "
1117 "[device address=0x%016llx] [size=%llu bytes] "
1118 "[cpu alloc address=0x%016llx] "
1119 "[cpu free address=0x%016llx]",
1120 ref->dev_addr, ref->size,
1121 phys_addr(entry),
1122 phys_addr(ref));
1123 }
1124
1125 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1126 ref->sg_call_ents != entry->sg_call_ents) {
1127 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1128 "DMA sg list with different entry count "
1129 "[map count=%d] [unmap count=%d]\n",
1130 entry->sg_call_ents, ref->sg_call_ents);
1131 }
1132
1133 /*
1134 * This may be no bug in reality - but most implementations of the
1135 * DMA API don't handle this properly, so check for it here
1136 */
1137 if (ref->direction != entry->direction) {
1138 err_printk(ref->dev, entry, "DMA-API: device driver frees "
1139 "DMA memory with different direction "
1140 "[device address=0x%016llx] [size=%llu bytes] "
1141 "[mapped with %s] [unmapped with %s]\n",
1142 ref->dev_addr, ref->size,
1143 dir2name[entry->direction],
1144 dir2name[ref->direction]);
1145 }
1146
1147 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1148 err_printk(ref->dev, entry,
1149 "DMA-API: device driver failed to check map error"
1150 "[device address=0x%016llx] [size=%llu bytes] "
1151 "[mapped as %s]",
1152 ref->dev_addr, ref->size,
1153 type2name[entry->type]);
1154 }
1155
1156 hash_bucket_del(entry);
1157 dma_entry_free(entry);
1158
1159 put_hash_bucket(bucket, &flags);
1160}
1161
1162static void check_for_stack(struct device *dev, void *addr)
1163{
1164 if (object_is_on_stack(addr))
1165 err_printk(dev, NULL, "DMA-API: device driver maps memory from "
1166 "stack [addr=%p]\n", addr);
1167}
1168
1169static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
1170{
1171 unsigned long a1 = (unsigned long)addr;
1172 unsigned long b1 = a1 + len;
1173 unsigned long a2 = (unsigned long)start;
1174 unsigned long b2 = (unsigned long)end;
1175
1176 return !(b1 <= a2 || a1 >= b2);
1177}
1178
1179static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1180{
1181 if (overlap(addr, len, _text, _etext) ||
1182 overlap(addr, len, __start_rodata, __end_rodata))
1183 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1184}
1185
1186static void check_sync(struct device *dev,
1187 struct dma_debug_entry *ref,
1188 bool to_cpu)
1189{
1190 struct dma_debug_entry *entry;
1191 struct hash_bucket *bucket;
1192 unsigned long flags;
1193
1194 bucket = get_hash_bucket(ref, &flags);
1195
1196 entry = bucket_find_contain(&bucket, ref, &flags);
1197
1198 if (!entry) {
1199 err_printk(dev, NULL, "DMA-API: device driver tries "
1200 "to sync DMA memory it has not allocated "
1201 "[device address=0x%016llx] [size=%llu bytes]\n",
1202 (unsigned long long)ref->dev_addr, ref->size);
1203 goto out;
1204 }
1205
1206 if (ref->size > entry->size) {
1207 err_printk(dev, entry, "DMA-API: device driver syncs"
1208 " DMA memory outside allocated range "
1209 "[device address=0x%016llx] "
1210 "[allocation size=%llu bytes] "
1211 "[sync offset+size=%llu]\n",
1212 entry->dev_addr, entry->size,
1213 ref->size);
1214 }
1215
1216 if (entry->direction == DMA_BIDIRECTIONAL)
1217 goto out;
1218
1219 if (ref->direction != entry->direction) {
1220 err_printk(dev, entry, "DMA-API: device driver syncs "
1221 "DMA memory with different direction "
1222 "[device address=0x%016llx] [size=%llu bytes] "
1223 "[mapped with %s] [synced with %s]\n",
1224 (unsigned long long)ref->dev_addr, entry->size,
1225 dir2name[entry->direction],
1226 dir2name[ref->direction]);
1227 }
1228
1229 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1230 !(ref->direction == DMA_TO_DEVICE))
1231 err_printk(dev, entry, "DMA-API: device driver syncs "
1232 "device read-only DMA memory for cpu "
1233 "[device address=0x%016llx] [size=%llu bytes] "
1234 "[mapped with %s] [synced with %s]\n",
1235 (unsigned long long)ref->dev_addr, entry->size,
1236 dir2name[entry->direction],
1237 dir2name[ref->direction]);
1238
1239 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1240 !(ref->direction == DMA_FROM_DEVICE))
1241 err_printk(dev, entry, "DMA-API: device driver syncs "
1242 "device write-only DMA memory to device "
1243 "[device address=0x%016llx] [size=%llu bytes] "
1244 "[mapped with %s] [synced with %s]\n",
1245 (unsigned long long)ref->dev_addr, entry->size,
1246 dir2name[entry->direction],
1247 dir2name[ref->direction]);
1248
1249out:
1250 put_hash_bucket(bucket, &flags);
1251}
1252
1253void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1254 size_t size, int direction, dma_addr_t dma_addr,
1255 bool map_single)
1256{
1257 struct dma_debug_entry *entry;
1258
1259 if (unlikely(dma_debug_disabled()))
1260 return;
1261
1262 if (dma_mapping_error(dev, dma_addr))
1263 return;
1264
1265 entry = dma_entry_alloc();
1266 if (!entry)
1267 return;
1268
1269 entry->dev = dev;
1270 entry->type = dma_debug_page;
1271 entry->pfn = page_to_pfn(page);
1272 entry->offset = offset,
1273 entry->dev_addr = dma_addr;
1274 entry->size = size;
1275 entry->direction = direction;
1276 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1277
1278 if (map_single)
1279 entry->type = dma_debug_single;
1280
1281 if (!PageHighMem(page)) {
1282 void *addr = page_address(page) + offset;
1283
1284 check_for_stack(dev, addr);
1285 check_for_illegal_area(dev, addr, size);
1286 }
1287
1288 add_dma_entry(entry);
1289}
1290EXPORT_SYMBOL(debug_dma_map_page);
1291
1292void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1293{
1294 struct dma_debug_entry ref;
1295 struct dma_debug_entry *entry;
1296 struct hash_bucket *bucket;
1297 unsigned long flags;
1298
1299 if (unlikely(dma_debug_disabled()))
1300 return;
1301
1302 ref.dev = dev;
1303 ref.dev_addr = dma_addr;
1304 bucket = get_hash_bucket(&ref, &flags);
1305
1306 list_for_each_entry(entry, &bucket->list, list) {
1307 if (!exact_match(&ref, entry))
1308 continue;
1309
1310 /*
1311 * The same physical address can be mapped multiple
1312 * times. Without a hardware IOMMU this results in the
1313 * same device addresses being put into the dma-debug
1314 * hash multiple times too. This can result in false
1315 * positives being reported. Therefore we implement a
1316 * best-fit algorithm here which updates the first entry
1317 * from the hash which fits the reference value and is
1318 * not currently listed as being checked.
1319 */
1320 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1321 entry->map_err_type = MAP_ERR_CHECKED;
1322 break;
1323 }
1324 }
1325
1326 put_hash_bucket(bucket, &flags);
1327}
1328EXPORT_SYMBOL(debug_dma_mapping_error);
1329
1330void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1331 size_t size, int direction, bool map_single)
1332{
1333 struct dma_debug_entry ref = {
1334 .type = dma_debug_page,
1335 .dev = dev,
1336 .dev_addr = addr,
1337 .size = size,
1338 .direction = direction,
1339 };
1340
1341 if (unlikely(dma_debug_disabled()))
1342 return;
1343
1344 if (map_single)
1345 ref.type = dma_debug_single;
1346
1347 check_unmap(&ref);
1348}
1349EXPORT_SYMBOL(debug_dma_unmap_page);
1350
1351void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1352 int nents, int mapped_ents, int direction)
1353{
1354 struct dma_debug_entry *entry;
1355 struct scatterlist *s;
1356 int i;
1357
1358 if (unlikely(dma_debug_disabled()))
1359 return;
1360
1361 for_each_sg(sg, s, mapped_ents, i) {
1362 entry = dma_entry_alloc();
1363 if (!entry)
1364 return;
1365
1366 entry->type = dma_debug_sg;
1367 entry->dev = dev;
1368 entry->pfn = page_to_pfn(sg_page(s));
1369 entry->offset = s->offset,
1370 entry->size = sg_dma_len(s);
1371 entry->dev_addr = sg_dma_address(s);
1372 entry->direction = direction;
1373 entry->sg_call_ents = nents;
1374 entry->sg_mapped_ents = mapped_ents;
1375
1376 if (!PageHighMem(sg_page(s))) {
1377 check_for_stack(dev, sg_virt(s));
1378 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1379 }
1380
1381 add_dma_entry(entry);
1382 }
1383}
1384EXPORT_SYMBOL(debug_dma_map_sg);
1385
1386static int get_nr_mapped_entries(struct device *dev,
1387 struct dma_debug_entry *ref)
1388{
1389 struct dma_debug_entry *entry;
1390 struct hash_bucket *bucket;
1391 unsigned long flags;
1392 int mapped_ents;
1393
1394 bucket = get_hash_bucket(ref, &flags);
1395 entry = bucket_find_exact(bucket, ref);
1396 mapped_ents = 0;
1397
1398 if (entry)
1399 mapped_ents = entry->sg_mapped_ents;
1400 put_hash_bucket(bucket, &flags);
1401
1402 return mapped_ents;
1403}
1404
1405void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1406 int nelems, int dir)
1407{
1408 struct scatterlist *s;
1409 int mapped_ents = 0, i;
1410
1411 if (unlikely(dma_debug_disabled()))
1412 return;
1413
1414 for_each_sg(sglist, s, nelems, i) {
1415
1416 struct dma_debug_entry ref = {
1417 .type = dma_debug_sg,
1418 .dev = dev,
1419 .pfn = page_to_pfn(sg_page(s)),
1420 .offset = s->offset,
1421 .dev_addr = sg_dma_address(s),
1422 .size = sg_dma_len(s),
1423 .direction = dir,
1424 .sg_call_ents = nelems,
1425 };
1426
1427 if (mapped_ents && i >= mapped_ents)
1428 break;
1429
1430 if (!i)
1431 mapped_ents = get_nr_mapped_entries(dev, &ref);
1432
1433 check_unmap(&ref);
1434 }
1435}
1436EXPORT_SYMBOL(debug_dma_unmap_sg);
1437
1438void debug_dma_alloc_coherent(struct device *dev, size_t size,
1439 dma_addr_t dma_addr, void *virt)
1440{
1441 struct dma_debug_entry *entry;
1442
1443 if (unlikely(dma_debug_disabled()))
1444 return;
1445
1446 if (unlikely(virt == NULL))
1447 return;
1448
1449 entry = dma_entry_alloc();
1450 if (!entry)
1451 return;
1452
1453 entry->type = dma_debug_coherent;
1454 entry->dev = dev;
1455 entry->pfn = page_to_pfn(virt_to_page(virt));
1456 entry->offset = (size_t) virt & PAGE_MASK;
1457 entry->size = size;
1458 entry->dev_addr = dma_addr;
1459 entry->direction = DMA_BIDIRECTIONAL;
1460
1461 add_dma_entry(entry);
1462}
1463EXPORT_SYMBOL(debug_dma_alloc_coherent);
1464
1465void debug_dma_free_coherent(struct device *dev, size_t size,
1466 void *virt, dma_addr_t addr)
1467{
1468 struct dma_debug_entry ref = {
1469 .type = dma_debug_coherent,
1470 .dev = dev,
1471 .pfn = page_to_pfn(virt_to_page(virt)),
1472 .offset = (size_t) virt & PAGE_MASK,
1473 .dev_addr = addr,
1474 .size = size,
1475 .direction = DMA_BIDIRECTIONAL,
1476 };
1477
1478 if (unlikely(dma_debug_disabled()))
1479 return;
1480
1481 check_unmap(&ref);
1482}
1483EXPORT_SYMBOL(debug_dma_free_coherent);
1484
1485void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1486 size_t size, int direction)
1487{
1488 struct dma_debug_entry ref;
1489
1490 if (unlikely(dma_debug_disabled()))
1491 return;
1492
1493 ref.type = dma_debug_single;
1494 ref.dev = dev;
1495 ref.dev_addr = dma_handle;
1496 ref.size = size;
1497 ref.direction = direction;
1498 ref.sg_call_ents = 0;
1499
1500 check_sync(dev, &ref, true);
1501}
1502EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1503
1504void debug_dma_sync_single_for_device(struct device *dev,
1505 dma_addr_t dma_handle, size_t size,
1506 int direction)
1507{
1508 struct dma_debug_entry ref;
1509
1510 if (unlikely(dma_debug_disabled()))
1511 return;
1512
1513 ref.type = dma_debug_single;
1514 ref.dev = dev;
1515 ref.dev_addr = dma_handle;
1516 ref.size = size;
1517 ref.direction = direction;
1518 ref.sg_call_ents = 0;
1519
1520 check_sync(dev, &ref, false);
1521}
1522EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1523
1524void debug_dma_sync_single_range_for_cpu(struct device *dev,
1525 dma_addr_t dma_handle,
1526 unsigned long offset, size_t size,
1527 int direction)
1528{
1529 struct dma_debug_entry ref;
1530
1531 if (unlikely(dma_debug_disabled()))
1532 return;
1533
1534 ref.type = dma_debug_single;
1535 ref.dev = dev;
1536 ref.dev_addr = dma_handle;
1537 ref.size = offset + size;
1538 ref.direction = direction;
1539 ref.sg_call_ents = 0;
1540
1541 check_sync(dev, &ref, true);
1542}
1543EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1544
1545void debug_dma_sync_single_range_for_device(struct device *dev,
1546 dma_addr_t dma_handle,
1547 unsigned long offset,
1548 size_t size, int direction)
1549{
1550 struct dma_debug_entry ref;
1551
1552 if (unlikely(dma_debug_disabled()))
1553 return;
1554
1555 ref.type = dma_debug_single;
1556 ref.dev = dev;
1557 ref.dev_addr = dma_handle;
1558 ref.size = offset + size;
1559 ref.direction = direction;
1560 ref.sg_call_ents = 0;
1561
1562 check_sync(dev, &ref, false);
1563}
1564EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1565
1566void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1567 int nelems, int direction)
1568{
1569 struct scatterlist *s;
1570 int mapped_ents = 0, i;
1571
1572 if (unlikely(dma_debug_disabled()))
1573 return;
1574
1575 for_each_sg(sg, s, nelems, i) {
1576
1577 struct dma_debug_entry ref = {
1578 .type = dma_debug_sg,
1579 .dev = dev,
1580 .pfn = page_to_pfn(sg_page(s)),
1581 .offset = s->offset,
1582 .dev_addr = sg_dma_address(s),
1583 .size = sg_dma_len(s),
1584 .direction = direction,
1585 .sg_call_ents = nelems,
1586 };
1587
1588 if (!i)
1589 mapped_ents = get_nr_mapped_entries(dev, &ref);
1590
1591 if (i >= mapped_ents)
1592 break;
1593
1594 check_sync(dev, &ref, true);
1595 }
1596}
1597EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1598
1599void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1600 int nelems, int direction)
1601{
1602 struct scatterlist *s;
1603 int mapped_ents = 0, i;
1604
1605 if (unlikely(dma_debug_disabled()))
1606 return;
1607
1608 for_each_sg(sg, s, nelems, i) {
1609
1610 struct dma_debug_entry ref = {
1611 .type = dma_debug_sg,
1612 .dev = dev,
1613 .pfn = page_to_pfn(sg_page(s)),
1614 .offset = s->offset,
1615 .dev_addr = sg_dma_address(s),
1616 .size = sg_dma_len(s),
1617 .direction = direction,
1618 .sg_call_ents = nelems,
1619 };
1620 if (!i)
1621 mapped_ents = get_nr_mapped_entries(dev, &ref);
1622
1623 if (i >= mapped_ents)
1624 break;
1625
1626 check_sync(dev, &ref, false);
1627 }
1628}
1629EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1630
1631static int __init dma_debug_driver_setup(char *str)
1632{
1633 int i;
1634
1635 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1636 current_driver_name[i] = *str;
1637 if (*str == 0)
1638 break;
1639 }
1640
1641 if (current_driver_name[0])
1642 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1643 current_driver_name);
1644
1645
1646 return 1;
1647}
1648__setup("dma_debug_driver=", dma_debug_driver_setup);