2 * Copyright (C) 2008 Advanced Micro Devices, Inc.
4 * Author: Joerg Roedel <joerg.roedel@amd.com>
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.
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.
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
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>
35 #include <asm/sections.h>
37 #define HASH_SIZE 1024ULL
38 #define HASH_FN_SHIFT 13
39 #define HASH_FN_MASK (HASH_SIZE - 1)
50 MAP_ERR_CHECK_NOT_APPLICABLE
,
55 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
58 * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
59 * @list: node on pre-allocated free_entries list
60 * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
61 * @type: single, page, sg, coherent
62 * @pfn: page frame of the start address
63 * @offset: offset of mapping relative to pfn
64 * @size: length of the mapping
65 * @direction: enum dma_data_direction
66 * @sg_call_ents: 'nents' from dma_map_sg
67 * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
68 * @map_err_type: track whether dma_mapping_error() was checked
69 * @stacktrace: support backtraces when a violation is detected
71 struct dma_debug_entry
{
72 struct list_head list
;
82 enum map_err_types map_err_type
;
83 #ifdef CONFIG_STACKTRACE
84 struct stack_trace stacktrace
;
85 unsigned long st_entries
[DMA_DEBUG_STACKTRACE_ENTRIES
];
89 typedef bool (*match_fn
)(struct dma_debug_entry
*, struct dma_debug_entry
*);
92 struct list_head list
;
94 } ____cacheline_aligned_in_smp
;
96 /* Hash list to save the allocated dma addresses */
97 static struct hash_bucket dma_entry_hash
[HASH_SIZE
];
98 /* List of pre-allocated dma_debug_entry's */
99 static LIST_HEAD(free_entries
);
100 /* Lock for the list above */
101 static DEFINE_SPINLOCK(free_entries_lock
);
103 /* Global disable flag - will be set in case of an error */
104 static bool global_disable __read_mostly
;
106 /* Early initialization disable flag, set at the end of dma_debug_init */
107 static bool dma_debug_initialized __read_mostly
;
109 static inline bool dma_debug_disabled(void)
111 return global_disable
|| !dma_debug_initialized
;
114 /* Global error count */
115 static u32 error_count
;
117 /* Global error show enable*/
118 static u32 show_all_errors __read_mostly
;
119 /* Number of errors to show */
120 static u32 show_num_errors
= 1;
122 static u32 num_free_entries
;
123 static u32 min_free_entries
;
124 static u32 nr_total_entries
;
126 /* number of preallocated entries requested by kernel cmdline */
127 static u32 req_entries
;
129 /* debugfs dentry's for the stuff above */
130 static struct dentry
*dma_debug_dent __read_mostly
;
131 static struct dentry
*global_disable_dent __read_mostly
;
132 static struct dentry
*error_count_dent __read_mostly
;
133 static struct dentry
*show_all_errors_dent __read_mostly
;
134 static struct dentry
*show_num_errors_dent __read_mostly
;
135 static struct dentry
*num_free_entries_dent __read_mostly
;
136 static struct dentry
*min_free_entries_dent __read_mostly
;
137 static struct dentry
*filter_dent __read_mostly
;
139 /* per-driver filter related state */
141 #define NAME_MAX_LEN 64
143 static char current_driver_name
[NAME_MAX_LEN
] __read_mostly
;
144 static struct device_driver
*current_driver __read_mostly
;
146 static DEFINE_RWLOCK(driver_name_lock
);
148 static const char *const maperr2str
[] = {
149 [MAP_ERR_CHECK_NOT_APPLICABLE
] = "dma map error check not applicable",
150 [MAP_ERR_NOT_CHECKED
] = "dma map error not checked",
151 [MAP_ERR_CHECKED
] = "dma map error checked",
154 static const char *type2name
[5] = { "single", "page",
155 "scather-gather", "coherent",
158 static const char *dir2name
[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
159 "DMA_FROM_DEVICE", "DMA_NONE" };
162 * The access to some variables in this macro is racy. We can't use atomic_t
163 * here because all these variables are exported to debugfs. Some of them even
164 * writeable. This is also the reason why a lock won't help much. But anyway,
165 * the races are no big deal. Here is why:
167 * error_count: the addition is racy, but the worst thing that can happen is
168 * that we don't count some errors
169 * show_num_errors: the subtraction is racy. Also no big deal because in
170 * worst case this will result in one warning more in the
171 * system log than the user configured. This variable is
172 * writeable via debugfs.
174 static inline void dump_entry_trace(struct dma_debug_entry
*entry
)
176 #ifdef CONFIG_STACKTRACE
178 pr_warning("Mapped at:\n");
179 print_stack_trace(&entry
->stacktrace
, 0);
184 static bool driver_filter(struct device
*dev
)
186 struct device_driver
*drv
;
190 /* driver filter off */
191 if (likely(!current_driver_name
[0]))
194 /* driver filter on and initialized */
195 if (current_driver
&& dev
&& dev
->driver
== current_driver
)
198 /* driver filter on, but we can't filter on a NULL device... */
202 if (current_driver
|| !current_driver_name
[0])
205 /* driver filter on but not yet initialized */
210 /* lock to protect against change of current_driver_name */
211 read_lock_irqsave(&driver_name_lock
, flags
);
215 strncmp(current_driver_name
, drv
->name
, NAME_MAX_LEN
- 1) == 0) {
216 current_driver
= drv
;
220 read_unlock_irqrestore(&driver_name_lock
, flags
);
225 #define err_printk(dev, entry, format, arg...) do { \
227 if (driver_filter(dev) && \
228 (show_all_errors || show_num_errors > 0)) { \
229 WARN(1, "%s %s: " format, \
230 dev ? dev_driver_string(dev) : "NULL", \
231 dev ? dev_name(dev) : "NULL", ## arg); \
232 dump_entry_trace(entry); \
234 if (!show_all_errors && show_num_errors > 0) \
235 show_num_errors -= 1; \
239 * Hash related functions
241 * Every DMA-API request is saved into a struct dma_debug_entry. To
242 * have quick access to these structs they are stored into a hash.
244 static int hash_fn(struct dma_debug_entry
*entry
)
247 * Hash function is based on the dma address.
248 * We use bits 20-27 here as the index into the hash
250 return (entry
->dev_addr
>> HASH_FN_SHIFT
) & HASH_FN_MASK
;
254 * Request exclusive access to a hash bucket for a given dma_debug_entry.
256 static struct hash_bucket
*get_hash_bucket(struct dma_debug_entry
*entry
,
257 unsigned long *flags
)
258 __acquires(&dma_entry_hash
[idx
].lock
)
260 int idx
= hash_fn(entry
);
261 unsigned long __flags
;
263 spin_lock_irqsave(&dma_entry_hash
[idx
].lock
, __flags
);
265 return &dma_entry_hash
[idx
];
269 * Give up exclusive access to the hash bucket
271 static void put_hash_bucket(struct hash_bucket
*bucket
,
272 unsigned long *flags
)
273 __releases(&bucket
->lock
)
275 unsigned long __flags
= *flags
;
277 spin_unlock_irqrestore(&bucket
->lock
, __flags
);
280 static bool exact_match(struct dma_debug_entry
*a
, struct dma_debug_entry
*b
)
282 return ((a
->dev_addr
== b
->dev_addr
) &&
283 (a
->dev
== b
->dev
)) ? true : false;
286 static bool containing_match(struct dma_debug_entry
*a
,
287 struct dma_debug_entry
*b
)
289 if (a
->dev
!= b
->dev
)
292 if ((b
->dev_addr
<= a
->dev_addr
) &&
293 ((b
->dev_addr
+ b
->size
) >= (a
->dev_addr
+ a
->size
)))
300 * Search a given entry in the hash bucket list
302 static struct dma_debug_entry
*__hash_bucket_find(struct hash_bucket
*bucket
,
303 struct dma_debug_entry
*ref
,
306 struct dma_debug_entry
*entry
, *ret
= NULL
;
307 int matches
= 0, match_lvl
, last_lvl
= -1;
309 list_for_each_entry(entry
, &bucket
->list
, list
) {
310 if (!match(ref
, entry
))
314 * Some drivers map the same physical address multiple
315 * times. Without a hardware IOMMU this results in the
316 * same device addresses being put into the dma-debug
317 * hash multiple times too. This can result in false
318 * positives being reported. Therefore we implement a
319 * best-fit algorithm here which returns the entry from
320 * the hash which fits best to the reference value
321 * instead of the first-fit.
325 entry
->size
== ref
->size
? ++match_lvl
: 0;
326 entry
->type
== ref
->type
? ++match_lvl
: 0;
327 entry
->direction
== ref
->direction
? ++match_lvl
: 0;
328 entry
->sg_call_ents
== ref
->sg_call_ents
? ++match_lvl
: 0;
330 if (match_lvl
== 4) {
331 /* perfect-fit - return the result */
333 } else if (match_lvl
> last_lvl
) {
335 * We found an entry that fits better then the
336 * previous one or it is the 1st match.
338 last_lvl
= match_lvl
;
344 * If we have multiple matches but no perfect-fit, just return
347 ret
= (matches
== 1) ? ret
: NULL
;
352 static struct dma_debug_entry
*bucket_find_exact(struct hash_bucket
*bucket
,
353 struct dma_debug_entry
*ref
)
355 return __hash_bucket_find(bucket
, ref
, exact_match
);
358 static struct dma_debug_entry
*bucket_find_contain(struct hash_bucket
**bucket
,
359 struct dma_debug_entry
*ref
,
360 unsigned long *flags
)
363 unsigned int max_range
= dma_get_max_seg_size(ref
->dev
);
364 struct dma_debug_entry
*entry
, index
= *ref
;
365 unsigned int range
= 0;
367 while (range
<= max_range
) {
368 entry
= __hash_bucket_find(*bucket
, ref
, containing_match
);
374 * Nothing found, go back a hash bucket
376 put_hash_bucket(*bucket
, flags
);
377 range
+= (1 << HASH_FN_SHIFT
);
378 index
.dev_addr
-= (1 << HASH_FN_SHIFT
);
379 *bucket
= get_hash_bucket(&index
, flags
);
386 * Add an entry to a hash bucket
388 static void hash_bucket_add(struct hash_bucket
*bucket
,
389 struct dma_debug_entry
*entry
)
391 list_add_tail(&entry
->list
, &bucket
->list
);
395 * Remove entry from a hash bucket list
397 static void hash_bucket_del(struct dma_debug_entry
*entry
)
399 list_del(&entry
->list
);
402 static unsigned long long phys_addr(struct dma_debug_entry
*entry
)
404 if (entry
->type
== dma_debug_resource
)
405 return __pfn_to_phys(entry
->pfn
) + entry
->offset
;
407 return page_to_phys(pfn_to_page(entry
->pfn
)) + entry
->offset
;
411 * Dump mapping entries for debugging purposes
413 void debug_dma_dump_mappings(struct device
*dev
)
417 for (idx
= 0; idx
< HASH_SIZE
; idx
++) {
418 struct hash_bucket
*bucket
= &dma_entry_hash
[idx
];
419 struct dma_debug_entry
*entry
;
422 spin_lock_irqsave(&bucket
->lock
, flags
);
424 list_for_each_entry(entry
, &bucket
->list
, list
) {
425 if (!dev
|| dev
== entry
->dev
) {
427 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
428 type2name
[entry
->type
], idx
,
429 phys_addr(entry
), entry
->pfn
,
430 entry
->dev_addr
, entry
->size
,
431 dir2name
[entry
->direction
],
432 maperr2str
[entry
->map_err_type
]);
436 spin_unlock_irqrestore(&bucket
->lock
, flags
);
439 EXPORT_SYMBOL(debug_dma_dump_mappings
);
442 * For each mapping (initial cacheline in the case of
443 * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
444 * scatterlist, or the cacheline specified in dma_map_single) insert
445 * into this tree using the cacheline as the key. At
446 * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If
447 * the entry already exists at insertion time add a tag as a reference
448 * count for the overlapping mappings. For now, the overlap tracking
449 * just ensures that 'unmaps' balance 'maps' before marking the
450 * cacheline idle, but we should also be flagging overlaps as an API
453 * Memory usage is mostly constrained by the maximum number of available
454 * dma-debug entries in that we need a free dma_debug_entry before
455 * inserting into the tree. In the case of dma_map_page and
456 * dma_alloc_coherent there is only one dma_debug_entry and one
457 * dma_active_cacheline entry to track per event. dma_map_sg(), on the
458 * other hand, consumes a single dma_debug_entry, but inserts 'nents'
459 * entries into the tree.
461 * At any time debug_dma_assert_idle() can be called to trigger a
462 * warning if any cachelines in the given page are in the active set.
464 static RADIX_TREE(dma_active_cacheline
, GFP_NOWAIT
);
465 static DEFINE_SPINLOCK(radix_lock
);
466 #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
467 #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
468 #define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
470 static phys_addr_t
to_cacheline_number(struct dma_debug_entry
*entry
)
472 return (entry
->pfn
<< CACHELINE_PER_PAGE_SHIFT
) +
473 (entry
->offset
>> L1_CACHE_SHIFT
);
476 static int active_cacheline_read_overlap(phys_addr_t cln
)
480 for (i
= RADIX_TREE_MAX_TAGS
- 1; i
>= 0; i
--)
481 if (radix_tree_tag_get(&dma_active_cacheline
, cln
, i
))
486 static int active_cacheline_set_overlap(phys_addr_t cln
, int overlap
)
490 if (overlap
> ACTIVE_CACHELINE_MAX_OVERLAP
|| overlap
< 0)
493 for (i
= RADIX_TREE_MAX_TAGS
- 1; i
>= 0; i
--)
494 if (overlap
& 1 << i
)
495 radix_tree_tag_set(&dma_active_cacheline
, cln
, i
);
497 radix_tree_tag_clear(&dma_active_cacheline
, cln
, i
);
502 static void active_cacheline_inc_overlap(phys_addr_t cln
)
504 int overlap
= active_cacheline_read_overlap(cln
);
506 overlap
= active_cacheline_set_overlap(cln
, ++overlap
);
508 /* If we overflowed the overlap counter then we're potentially
509 * leaking dma-mappings. Otherwise, if maps and unmaps are
510 * balanced then this overflow may cause false negatives in
511 * debug_dma_assert_idle() as the cacheline may be marked idle
514 WARN_ONCE(overlap
> ACTIVE_CACHELINE_MAX_OVERLAP
,
515 "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
516 ACTIVE_CACHELINE_MAX_OVERLAP
, &cln
);
519 static int active_cacheline_dec_overlap(phys_addr_t cln
)
521 int overlap
= active_cacheline_read_overlap(cln
);
523 return active_cacheline_set_overlap(cln
, --overlap
);
526 static int active_cacheline_insert(struct dma_debug_entry
*entry
)
528 phys_addr_t cln
= to_cacheline_number(entry
);
532 /* If the device is not writing memory then we don't have any
533 * concerns about the cpu consuming stale data. This mitigates
534 * legitimate usages of overlapping mappings.
536 if (entry
->direction
== DMA_TO_DEVICE
)
539 spin_lock_irqsave(&radix_lock
, flags
);
540 rc
= radix_tree_insert(&dma_active_cacheline
, cln
, entry
);
542 active_cacheline_inc_overlap(cln
);
543 spin_unlock_irqrestore(&radix_lock
, flags
);
548 static void active_cacheline_remove(struct dma_debug_entry
*entry
)
550 phys_addr_t cln
= to_cacheline_number(entry
);
553 /* ...mirror the insert case */
554 if (entry
->direction
== DMA_TO_DEVICE
)
557 spin_lock_irqsave(&radix_lock
, flags
);
558 /* since we are counting overlaps the final put of the
559 * cacheline will occur when the overlap count is 0.
560 * active_cacheline_dec_overlap() returns -1 in that case
562 if (active_cacheline_dec_overlap(cln
) < 0)
563 radix_tree_delete(&dma_active_cacheline
, cln
);
564 spin_unlock_irqrestore(&radix_lock
, flags
);
568 * debug_dma_assert_idle() - assert that a page is not undergoing dma
569 * @page: page to lookup in the dma_active_cacheline tree
571 * Place a call to this routine in cases where the cpu touching the page
572 * before the dma completes (page is dma_unmapped) will lead to data
575 void debug_dma_assert_idle(struct page
*page
)
577 static struct dma_debug_entry
*ents
[CACHELINES_PER_PAGE
];
578 struct dma_debug_entry
*entry
= NULL
;
579 void **results
= (void **) &ents
;
580 unsigned int nents
, i
;
584 if (dma_debug_disabled())
590 cln
= (phys_addr_t
) page_to_pfn(page
) << CACHELINE_PER_PAGE_SHIFT
;
591 spin_lock_irqsave(&radix_lock
, flags
);
592 nents
= radix_tree_gang_lookup(&dma_active_cacheline
, results
, cln
,
593 CACHELINES_PER_PAGE
);
594 for (i
= 0; i
< nents
; i
++) {
595 phys_addr_t ent_cln
= to_cacheline_number(ents
[i
]);
597 if (ent_cln
== cln
) {
600 } else if (ent_cln
>= cln
+ CACHELINES_PER_PAGE
)
603 spin_unlock_irqrestore(&radix_lock
, flags
);
608 cln
= to_cacheline_number(entry
);
609 err_printk(entry
->dev
, entry
,
610 "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
615 * Wrapper function for adding an entry to the hash.
616 * This function takes care of locking itself.
618 static void add_dma_entry(struct dma_debug_entry
*entry
)
620 struct hash_bucket
*bucket
;
624 bucket
= get_hash_bucket(entry
, &flags
);
625 hash_bucket_add(bucket
, entry
);
626 put_hash_bucket(bucket
, &flags
);
628 rc
= active_cacheline_insert(entry
);
630 pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
631 global_disable
= true;
634 /* TODO: report -EEXIST errors here as overlapping mappings are
635 * not supported by the DMA API
639 static struct dma_debug_entry
*__dma_entry_alloc(void)
641 struct dma_debug_entry
*entry
;
643 entry
= list_entry(free_entries
.next
, struct dma_debug_entry
, list
);
644 list_del(&entry
->list
);
645 memset(entry
, 0, sizeof(*entry
));
647 num_free_entries
-= 1;
648 if (num_free_entries
< min_free_entries
)
649 min_free_entries
= num_free_entries
;
654 /* struct dma_entry allocator
656 * The next two functions implement the allocator for
657 * struct dma_debug_entries.
659 static struct dma_debug_entry
*dma_entry_alloc(void)
661 struct dma_debug_entry
*entry
;
664 spin_lock_irqsave(&free_entries_lock
, flags
);
666 if (list_empty(&free_entries
)) {
667 global_disable
= true;
668 spin_unlock_irqrestore(&free_entries_lock
, flags
);
669 pr_err("DMA-API: debugging out of memory - disabling\n");
673 entry
= __dma_entry_alloc();
675 spin_unlock_irqrestore(&free_entries_lock
, flags
);
677 #ifdef CONFIG_STACKTRACE
678 entry
->stacktrace
.max_entries
= DMA_DEBUG_STACKTRACE_ENTRIES
;
679 entry
->stacktrace
.entries
= entry
->st_entries
;
680 entry
->stacktrace
.skip
= 2;
681 save_stack_trace(&entry
->stacktrace
);
687 static void dma_entry_free(struct dma_debug_entry
*entry
)
691 active_cacheline_remove(entry
);
694 * add to beginning of the list - this way the entries are
695 * more likely cache hot when they are reallocated.
697 spin_lock_irqsave(&free_entries_lock
, flags
);
698 list_add(&entry
->list
, &free_entries
);
699 num_free_entries
+= 1;
700 spin_unlock_irqrestore(&free_entries_lock
, flags
);
703 int dma_debug_resize_entries(u32 num_entries
)
705 int i
, delta
, ret
= 0;
707 struct dma_debug_entry
*entry
;
710 spin_lock_irqsave(&free_entries_lock
, flags
);
712 if (nr_total_entries
< num_entries
) {
713 delta
= num_entries
- nr_total_entries
;
715 spin_unlock_irqrestore(&free_entries_lock
, flags
);
717 for (i
= 0; i
< delta
; i
++) {
718 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
722 list_add_tail(&entry
->list
, &tmp
);
725 spin_lock_irqsave(&free_entries_lock
, flags
);
727 list_splice(&tmp
, &free_entries
);
728 nr_total_entries
+= i
;
729 num_free_entries
+= i
;
731 delta
= nr_total_entries
- num_entries
;
733 for (i
= 0; i
< delta
&& !list_empty(&free_entries
); i
++) {
734 entry
= __dma_entry_alloc();
738 nr_total_entries
-= i
;
741 if (nr_total_entries
!= num_entries
)
744 spin_unlock_irqrestore(&free_entries_lock
, flags
);
748 EXPORT_SYMBOL(dma_debug_resize_entries
);
751 * DMA-API debugging init code
753 * The init code does two things:
754 * 1. Initialize core data structures
755 * 2. Preallocate a given number of dma_debug_entry structs
758 static int prealloc_memory(u32 num_entries
)
760 struct dma_debug_entry
*entry
, *next_entry
;
763 for (i
= 0; i
< num_entries
; ++i
) {
764 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
768 list_add_tail(&entry
->list
, &free_entries
);
771 num_free_entries
= num_entries
;
772 min_free_entries
= num_entries
;
774 pr_info("DMA-API: preallocated %d debug entries\n", num_entries
);
780 list_for_each_entry_safe(entry
, next_entry
, &free_entries
, list
) {
781 list_del(&entry
->list
);
788 static ssize_t
filter_read(struct file
*file
, char __user
*user_buf
,
789 size_t count
, loff_t
*ppos
)
791 char buf
[NAME_MAX_LEN
+ 1];
795 if (!current_driver_name
[0])
799 * We can't copy to userspace directly because current_driver_name can
800 * only be read under the driver_name_lock with irqs disabled. So
801 * create a temporary copy first.
803 read_lock_irqsave(&driver_name_lock
, flags
);
804 len
= scnprintf(buf
, NAME_MAX_LEN
+ 1, "%s\n", current_driver_name
);
805 read_unlock_irqrestore(&driver_name_lock
, flags
);
807 return simple_read_from_buffer(user_buf
, count
, ppos
, buf
, len
);
810 static ssize_t
filter_write(struct file
*file
, const char __user
*userbuf
,
811 size_t count
, loff_t
*ppos
)
813 char buf
[NAME_MAX_LEN
];
819 * We can't copy from userspace directly. Access to
820 * current_driver_name is protected with a write_lock with irqs
821 * disabled. Since copy_from_user can fault and may sleep we
822 * need to copy to temporary buffer first
824 len
= min(count
, (size_t)(NAME_MAX_LEN
- 1));
825 if (copy_from_user(buf
, userbuf
, len
))
830 write_lock_irqsave(&driver_name_lock
, flags
);
833 * Now handle the string we got from userspace very carefully.
835 * - only use the first token we got
836 * - token delimiter is everything looking like a space
837 * character (' ', '\n', '\t' ...)
840 if (!isalnum(buf
[0])) {
842 * If the first character userspace gave us is not
843 * alphanumerical then assume the filter should be
846 if (current_driver_name
[0])
847 pr_info("DMA-API: switching off dma-debug driver filter\n");
848 current_driver_name
[0] = 0;
849 current_driver
= NULL
;
854 * Now parse out the first token and use it as the name for the
855 * driver to filter for.
857 for (i
= 0; i
< NAME_MAX_LEN
- 1; ++i
) {
858 current_driver_name
[i
] = buf
[i
];
859 if (isspace(buf
[i
]) || buf
[i
] == ' ' || buf
[i
] == 0)
862 current_driver_name
[i
] = 0;
863 current_driver
= NULL
;
865 pr_info("DMA-API: enable driver filter for driver [%s]\n",
866 current_driver_name
);
869 write_unlock_irqrestore(&driver_name_lock
, flags
);
874 static const struct file_operations filter_fops
= {
876 .write
= filter_write
,
877 .llseek
= default_llseek
,
880 static int dma_debug_fs_init(void)
882 dma_debug_dent
= debugfs_create_dir("dma-api", NULL
);
883 if (!dma_debug_dent
) {
884 pr_err("DMA-API: can not create debugfs directory\n");
888 global_disable_dent
= debugfs_create_bool("disabled", 0444,
891 if (!global_disable_dent
)
894 error_count_dent
= debugfs_create_u32("error_count", 0444,
895 dma_debug_dent
, &error_count
);
896 if (!error_count_dent
)
899 show_all_errors_dent
= debugfs_create_u32("all_errors", 0644,
902 if (!show_all_errors_dent
)
905 show_num_errors_dent
= debugfs_create_u32("num_errors", 0644,
908 if (!show_num_errors_dent
)
911 num_free_entries_dent
= debugfs_create_u32("num_free_entries", 0444,
914 if (!num_free_entries_dent
)
917 min_free_entries_dent
= debugfs_create_u32("min_free_entries", 0444,
920 if (!min_free_entries_dent
)
923 filter_dent
= debugfs_create_file("driver_filter", 0644,
924 dma_debug_dent
, NULL
, &filter_fops
);
931 debugfs_remove_recursive(dma_debug_dent
);
936 static int device_dma_allocations(struct device
*dev
, struct dma_debug_entry
**out_entry
)
938 struct dma_debug_entry
*entry
;
942 local_irq_save(flags
);
944 for (i
= 0; i
< HASH_SIZE
; ++i
) {
945 spin_lock(&dma_entry_hash
[i
].lock
);
946 list_for_each_entry(entry
, &dma_entry_hash
[i
].list
, list
) {
947 if (entry
->dev
== dev
) {
952 spin_unlock(&dma_entry_hash
[i
].lock
);
955 local_irq_restore(flags
);
960 static int dma_debug_device_change(struct notifier_block
*nb
, unsigned long action
, void *data
)
962 struct device
*dev
= data
;
963 struct dma_debug_entry
*uninitialized_var(entry
);
966 if (dma_debug_disabled())
970 case BUS_NOTIFY_UNBOUND_DRIVER
:
971 count
= device_dma_allocations(dev
, &entry
);
974 err_printk(dev
, entry
, "DMA-API: device driver has pending "
975 "DMA allocations while released from device "
977 "One of leaked entries details: "
978 "[device address=0x%016llx] [size=%llu bytes] "
979 "[mapped with %s] [mapped as %s]\n",
980 count
, entry
->dev_addr
, entry
->size
,
981 dir2name
[entry
->direction
], type2name
[entry
->type
]);
990 void dma_debug_add_bus(struct bus_type
*bus
)
992 struct notifier_block
*nb
;
994 if (dma_debug_disabled())
997 nb
= kzalloc(sizeof(struct notifier_block
), GFP_KERNEL
);
999 pr_err("dma_debug_add_bus: out of memory\n");
1003 nb
->notifier_call
= dma_debug_device_change
;
1005 bus_register_notifier(bus
, nb
);
1009 * Let the architectures decide how many entries should be preallocated.
1011 void dma_debug_init(u32 num_entries
)
1015 /* Do not use dma_debug_initialized here, since we really want to be
1016 * called to set dma_debug_initialized
1021 for (i
= 0; i
< HASH_SIZE
; ++i
) {
1022 INIT_LIST_HEAD(&dma_entry_hash
[i
].list
);
1023 spin_lock_init(&dma_entry_hash
[i
].lock
);
1026 if (dma_debug_fs_init() != 0) {
1027 pr_err("DMA-API: error creating debugfs entries - disabling\n");
1028 global_disable
= true;
1034 num_entries
= req_entries
;
1036 if (prealloc_memory(num_entries
) != 0) {
1037 pr_err("DMA-API: debugging out of memory error - disabled\n");
1038 global_disable
= true;
1043 nr_total_entries
= num_free_entries
;
1045 dma_debug_initialized
= true;
1047 pr_info("DMA-API: debugging enabled by kernel config\n");
1050 static __init
int dma_debug_cmdline(char *str
)
1055 if (strncmp(str
, "off", 3) == 0) {
1056 pr_info("DMA-API: debugging disabled on kernel command line\n");
1057 global_disable
= true;
1063 static __init
int dma_debug_entries_cmdline(char *str
)
1070 res
= get_option(&str
, &req_entries
);
1078 __setup("dma_debug=", dma_debug_cmdline
);
1079 __setup("dma_debug_entries=", dma_debug_entries_cmdline
);
1081 static void check_unmap(struct dma_debug_entry
*ref
)
1083 struct dma_debug_entry
*entry
;
1084 struct hash_bucket
*bucket
;
1085 unsigned long flags
;
1087 bucket
= get_hash_bucket(ref
, &flags
);
1088 entry
= bucket_find_exact(bucket
, ref
);
1091 /* must drop lock before calling dma_mapping_error */
1092 put_hash_bucket(bucket
, &flags
);
1094 if (dma_mapping_error(ref
->dev
, ref
->dev_addr
)) {
1095 err_printk(ref
->dev
, NULL
,
1096 "DMA-API: device driver tries to free an "
1097 "invalid DMA memory address\n");
1099 err_printk(ref
->dev
, NULL
,
1100 "DMA-API: device driver tries to free DMA "
1101 "memory it has not allocated [device "
1102 "address=0x%016llx] [size=%llu bytes]\n",
1103 ref
->dev_addr
, ref
->size
);
1108 if (ref
->size
!= entry
->size
) {
1109 err_printk(ref
->dev
, entry
, "DMA-API: device driver frees "
1110 "DMA memory with different size "
1111 "[device address=0x%016llx] [map size=%llu bytes] "
1112 "[unmap size=%llu bytes]\n",
1113 ref
->dev_addr
, entry
->size
, ref
->size
);
1116 if (ref
->type
!= entry
->type
) {
1117 err_printk(ref
->dev
, entry
, "DMA-API: device driver frees "
1118 "DMA memory with wrong function "
1119 "[device address=0x%016llx] [size=%llu bytes] "
1120 "[mapped as %s] [unmapped as %s]\n",
1121 ref
->dev_addr
, ref
->size
,
1122 type2name
[entry
->type
], type2name
[ref
->type
]);
1123 } else if ((entry
->type
== dma_debug_coherent
) &&
1124 (phys_addr(ref
) != phys_addr(entry
))) {
1125 err_printk(ref
->dev
, entry
, "DMA-API: device driver frees "
1126 "DMA memory with different CPU address "
1127 "[device address=0x%016llx] [size=%llu bytes] "
1128 "[cpu alloc address=0x%016llx] "
1129 "[cpu free address=0x%016llx]",
1130 ref
->dev_addr
, ref
->size
,
1135 if (ref
->sg_call_ents
&& ref
->type
== dma_debug_sg
&&
1136 ref
->sg_call_ents
!= entry
->sg_call_ents
) {
1137 err_printk(ref
->dev
, entry
, "DMA-API: device driver frees "
1138 "DMA sg list with different entry count "
1139 "[map count=%d] [unmap count=%d]\n",
1140 entry
->sg_call_ents
, ref
->sg_call_ents
);
1144 * This may be no bug in reality - but most implementations of the
1145 * DMA API don't handle this properly, so check for it here
1147 if (ref
->direction
!= entry
->direction
) {
1148 err_printk(ref
->dev
, entry
, "DMA-API: device driver frees "
1149 "DMA memory with different direction "
1150 "[device address=0x%016llx] [size=%llu bytes] "
1151 "[mapped with %s] [unmapped with %s]\n",
1152 ref
->dev_addr
, ref
->size
,
1153 dir2name
[entry
->direction
],
1154 dir2name
[ref
->direction
]);
1157 if (entry
->map_err_type
== MAP_ERR_NOT_CHECKED
) {
1158 err_printk(ref
->dev
, entry
,
1159 "DMA-API: device driver failed to check map error"
1160 "[device address=0x%016llx] [size=%llu bytes] "
1162 ref
->dev_addr
, ref
->size
,
1163 type2name
[entry
->type
]);
1166 hash_bucket_del(entry
);
1167 dma_entry_free(entry
);
1169 put_hash_bucket(bucket
, &flags
);
1172 static void check_for_stack(struct device
*dev
, void *addr
)
1174 if (object_is_on_stack(addr
))
1175 err_printk(dev
, NULL
, "DMA-API: device driver maps memory from "
1176 "stack [addr=%p]\n", addr
);
1179 static inline bool overlap(void *addr
, unsigned long len
, void *start
, void *end
)
1181 unsigned long a1
= (unsigned long)addr
;
1182 unsigned long b1
= a1
+ len
;
1183 unsigned long a2
= (unsigned long)start
;
1184 unsigned long b2
= (unsigned long)end
;
1186 return !(b1
<= a2
|| a1
>= b2
);
1189 static void check_for_illegal_area(struct device
*dev
, void *addr
, unsigned long len
)
1191 if (overlap(addr
, len
, _stext
, _etext
) ||
1192 overlap(addr
, len
, __start_rodata
, __end_rodata
))
1193 err_printk(dev
, NULL
, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr
, len
);
1196 static void check_sync(struct device
*dev
,
1197 struct dma_debug_entry
*ref
,
1200 struct dma_debug_entry
*entry
;
1201 struct hash_bucket
*bucket
;
1202 unsigned long flags
;
1204 bucket
= get_hash_bucket(ref
, &flags
);
1206 entry
= bucket_find_contain(&bucket
, ref
, &flags
);
1209 err_printk(dev
, NULL
, "DMA-API: device driver tries "
1210 "to sync DMA memory it has not allocated "
1211 "[device address=0x%016llx] [size=%llu bytes]\n",
1212 (unsigned long long)ref
->dev_addr
, ref
->size
);
1216 if (ref
->size
> entry
->size
) {
1217 err_printk(dev
, entry
, "DMA-API: device driver syncs"
1218 " DMA memory outside allocated range "
1219 "[device address=0x%016llx] "
1220 "[allocation size=%llu bytes] "
1221 "[sync offset+size=%llu]\n",
1222 entry
->dev_addr
, entry
->size
,
1226 if (entry
->direction
== DMA_BIDIRECTIONAL
)
1229 if (ref
->direction
!= entry
->direction
) {
1230 err_printk(dev
, entry
, "DMA-API: device driver syncs "
1231 "DMA memory with different direction "
1232 "[device address=0x%016llx] [size=%llu bytes] "
1233 "[mapped with %s] [synced with %s]\n",
1234 (unsigned long long)ref
->dev_addr
, entry
->size
,
1235 dir2name
[entry
->direction
],
1236 dir2name
[ref
->direction
]);
1239 if (to_cpu
&& !(entry
->direction
== DMA_FROM_DEVICE
) &&
1240 !(ref
->direction
== DMA_TO_DEVICE
))
1241 err_printk(dev
, entry
, "DMA-API: device driver syncs "
1242 "device read-only DMA memory for cpu "
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
]);
1249 if (!to_cpu
&& !(entry
->direction
== DMA_TO_DEVICE
) &&
1250 !(ref
->direction
== DMA_FROM_DEVICE
))
1251 err_printk(dev
, entry
, "DMA-API: device driver syncs "
1252 "device write-only DMA memory to device "
1253 "[device address=0x%016llx] [size=%llu bytes] "
1254 "[mapped with %s] [synced with %s]\n",
1255 (unsigned long long)ref
->dev_addr
, entry
->size
,
1256 dir2name
[entry
->direction
],
1257 dir2name
[ref
->direction
]);
1259 if (ref
->sg_call_ents
&& ref
->type
== dma_debug_sg
&&
1260 ref
->sg_call_ents
!= entry
->sg_call_ents
) {
1261 err_printk(ref
->dev
, entry
, "DMA-API: device driver syncs "
1262 "DMA sg list with different entry count "
1263 "[map count=%d] [sync count=%d]\n",
1264 entry
->sg_call_ents
, ref
->sg_call_ents
);
1268 put_hash_bucket(bucket
, &flags
);
1271 void debug_dma_map_page(struct device
*dev
, struct page
*page
, size_t offset
,
1272 size_t size
, int direction
, dma_addr_t dma_addr
,
1275 struct dma_debug_entry
*entry
;
1277 if (unlikely(dma_debug_disabled()))
1280 if (dma_mapping_error(dev
, dma_addr
))
1283 entry
= dma_entry_alloc();
1288 entry
->type
= dma_debug_page
;
1289 entry
->pfn
= page_to_pfn(page
);
1290 entry
->offset
= offset
,
1291 entry
->dev_addr
= dma_addr
;
1293 entry
->direction
= direction
;
1294 entry
->map_err_type
= MAP_ERR_NOT_CHECKED
;
1297 entry
->type
= dma_debug_single
;
1299 if (!PageHighMem(page
)) {
1300 void *addr
= page_address(page
) + offset
;
1302 check_for_stack(dev
, addr
);
1303 check_for_illegal_area(dev
, addr
, size
);
1306 add_dma_entry(entry
);
1308 EXPORT_SYMBOL(debug_dma_map_page
);
1310 void debug_dma_mapping_error(struct device
*dev
, dma_addr_t dma_addr
)
1312 struct dma_debug_entry ref
;
1313 struct dma_debug_entry
*entry
;
1314 struct hash_bucket
*bucket
;
1315 unsigned long flags
;
1317 if (unlikely(dma_debug_disabled()))
1321 ref
.dev_addr
= dma_addr
;
1322 bucket
= get_hash_bucket(&ref
, &flags
);
1324 list_for_each_entry(entry
, &bucket
->list
, list
) {
1325 if (!exact_match(&ref
, entry
))
1329 * The same physical address can be mapped multiple
1330 * times. Without a hardware IOMMU this results in the
1331 * same device addresses being put into the dma-debug
1332 * hash multiple times too. This can result in false
1333 * positives being reported. Therefore we implement a
1334 * best-fit algorithm here which updates the first entry
1335 * from the hash which fits the reference value and is
1336 * not currently listed as being checked.
1338 if (entry
->map_err_type
== MAP_ERR_NOT_CHECKED
) {
1339 entry
->map_err_type
= MAP_ERR_CHECKED
;
1344 put_hash_bucket(bucket
, &flags
);
1346 EXPORT_SYMBOL(debug_dma_mapping_error
);
1348 void debug_dma_unmap_page(struct device
*dev
, dma_addr_t addr
,
1349 size_t size
, int direction
, bool map_single
)
1351 struct dma_debug_entry ref
= {
1352 .type
= dma_debug_page
,
1356 .direction
= direction
,
1359 if (unlikely(dma_debug_disabled()))
1363 ref
.type
= dma_debug_single
;
1367 EXPORT_SYMBOL(debug_dma_unmap_page
);
1369 void debug_dma_map_sg(struct device
*dev
, struct scatterlist
*sg
,
1370 int nents
, int mapped_ents
, int direction
)
1372 struct dma_debug_entry
*entry
;
1373 struct scatterlist
*s
;
1376 if (unlikely(dma_debug_disabled()))
1379 for_each_sg(sg
, s
, mapped_ents
, i
) {
1380 entry
= dma_entry_alloc();
1384 entry
->type
= dma_debug_sg
;
1386 entry
->pfn
= page_to_pfn(sg_page(s
));
1387 entry
->offset
= s
->offset
,
1388 entry
->size
= sg_dma_len(s
);
1389 entry
->dev_addr
= sg_dma_address(s
);
1390 entry
->direction
= direction
;
1391 entry
->sg_call_ents
= nents
;
1392 entry
->sg_mapped_ents
= mapped_ents
;
1394 if (!PageHighMem(sg_page(s
))) {
1395 check_for_stack(dev
, sg_virt(s
));
1396 check_for_illegal_area(dev
, sg_virt(s
), sg_dma_len(s
));
1399 add_dma_entry(entry
);
1402 EXPORT_SYMBOL(debug_dma_map_sg
);
1404 static int get_nr_mapped_entries(struct device
*dev
,
1405 struct dma_debug_entry
*ref
)
1407 struct dma_debug_entry
*entry
;
1408 struct hash_bucket
*bucket
;
1409 unsigned long flags
;
1412 bucket
= get_hash_bucket(ref
, &flags
);
1413 entry
= bucket_find_exact(bucket
, ref
);
1417 mapped_ents
= entry
->sg_mapped_ents
;
1418 put_hash_bucket(bucket
, &flags
);
1423 void debug_dma_unmap_sg(struct device
*dev
, struct scatterlist
*sglist
,
1424 int nelems
, int dir
)
1426 struct scatterlist
*s
;
1427 int mapped_ents
= 0, i
;
1429 if (unlikely(dma_debug_disabled()))
1432 for_each_sg(sglist
, s
, nelems
, i
) {
1434 struct dma_debug_entry ref
= {
1435 .type
= dma_debug_sg
,
1437 .pfn
= page_to_pfn(sg_page(s
)),
1438 .offset
= s
->offset
,
1439 .dev_addr
= sg_dma_address(s
),
1440 .size
= sg_dma_len(s
),
1442 .sg_call_ents
= nelems
,
1445 if (mapped_ents
&& i
>= mapped_ents
)
1449 mapped_ents
= get_nr_mapped_entries(dev
, &ref
);
1454 EXPORT_SYMBOL(debug_dma_unmap_sg
);
1456 void debug_dma_alloc_coherent(struct device
*dev
, size_t size
,
1457 dma_addr_t dma_addr
, void *virt
)
1459 struct dma_debug_entry
*entry
;
1461 if (unlikely(dma_debug_disabled()))
1464 if (unlikely(virt
== NULL
))
1467 entry
= dma_entry_alloc();
1471 entry
->type
= dma_debug_coherent
;
1473 entry
->pfn
= page_to_pfn(virt_to_page(virt
));
1474 entry
->offset
= (size_t) virt
& ~PAGE_MASK
;
1476 entry
->dev_addr
= dma_addr
;
1477 entry
->direction
= DMA_BIDIRECTIONAL
;
1479 add_dma_entry(entry
);
1481 EXPORT_SYMBOL(debug_dma_alloc_coherent
);
1483 void debug_dma_free_coherent(struct device
*dev
, size_t size
,
1484 void *virt
, dma_addr_t addr
)
1486 struct dma_debug_entry ref
= {
1487 .type
= dma_debug_coherent
,
1489 .pfn
= page_to_pfn(virt_to_page(virt
)),
1490 .offset
= (size_t) virt
& ~PAGE_MASK
,
1493 .direction
= DMA_BIDIRECTIONAL
,
1496 if (unlikely(dma_debug_disabled()))
1501 EXPORT_SYMBOL(debug_dma_free_coherent
);
1503 void debug_dma_map_resource(struct device
*dev
, phys_addr_t addr
, size_t size
,
1504 int direction
, dma_addr_t dma_addr
)
1506 struct dma_debug_entry
*entry
;
1508 if (unlikely(dma_debug_disabled()))
1511 entry
= dma_entry_alloc();
1515 entry
->type
= dma_debug_resource
;
1517 entry
->pfn
= __phys_to_pfn(addr
);
1518 entry
->offset
= offset_in_page(addr
);
1520 entry
->dev_addr
= dma_addr
;
1521 entry
->direction
= direction
;
1522 entry
->map_err_type
= MAP_ERR_NOT_CHECKED
;
1524 add_dma_entry(entry
);
1526 EXPORT_SYMBOL(debug_dma_map_resource
);
1528 void debug_dma_unmap_resource(struct device
*dev
, dma_addr_t dma_addr
,
1529 size_t size
, int direction
)
1531 struct dma_debug_entry ref
= {
1532 .type
= dma_debug_resource
,
1534 .dev_addr
= dma_addr
,
1536 .direction
= direction
,
1539 if (unlikely(dma_debug_disabled()))
1544 EXPORT_SYMBOL(debug_dma_unmap_resource
);
1546 void debug_dma_sync_single_for_cpu(struct device
*dev
, dma_addr_t dma_handle
,
1547 size_t size
, int direction
)
1549 struct dma_debug_entry ref
;
1551 if (unlikely(dma_debug_disabled()))
1554 ref
.type
= dma_debug_single
;
1556 ref
.dev_addr
= dma_handle
;
1558 ref
.direction
= direction
;
1559 ref
.sg_call_ents
= 0;
1561 check_sync(dev
, &ref
, true);
1563 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu
);
1565 void debug_dma_sync_single_for_device(struct device
*dev
,
1566 dma_addr_t dma_handle
, size_t size
,
1569 struct dma_debug_entry ref
;
1571 if (unlikely(dma_debug_disabled()))
1574 ref
.type
= dma_debug_single
;
1576 ref
.dev_addr
= dma_handle
;
1578 ref
.direction
= direction
;
1579 ref
.sg_call_ents
= 0;
1581 check_sync(dev
, &ref
, false);
1583 EXPORT_SYMBOL(debug_dma_sync_single_for_device
);
1585 void debug_dma_sync_single_range_for_cpu(struct device
*dev
,
1586 dma_addr_t dma_handle
,
1587 unsigned long offset
, size_t size
,
1590 struct dma_debug_entry ref
;
1592 if (unlikely(dma_debug_disabled()))
1595 ref
.type
= dma_debug_single
;
1597 ref
.dev_addr
= dma_handle
;
1598 ref
.size
= offset
+ size
;
1599 ref
.direction
= direction
;
1600 ref
.sg_call_ents
= 0;
1602 check_sync(dev
, &ref
, true);
1604 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu
);
1606 void debug_dma_sync_single_range_for_device(struct device
*dev
,
1607 dma_addr_t dma_handle
,
1608 unsigned long offset
,
1609 size_t size
, int direction
)
1611 struct dma_debug_entry ref
;
1613 if (unlikely(dma_debug_disabled()))
1616 ref
.type
= dma_debug_single
;
1618 ref
.dev_addr
= dma_handle
;
1619 ref
.size
= offset
+ size
;
1620 ref
.direction
= direction
;
1621 ref
.sg_call_ents
= 0;
1623 check_sync(dev
, &ref
, false);
1625 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device
);
1627 void debug_dma_sync_sg_for_cpu(struct device
*dev
, struct scatterlist
*sg
,
1628 int nelems
, int direction
)
1630 struct scatterlist
*s
;
1631 int mapped_ents
= 0, i
;
1633 if (unlikely(dma_debug_disabled()))
1636 for_each_sg(sg
, s
, nelems
, i
) {
1638 struct dma_debug_entry ref
= {
1639 .type
= dma_debug_sg
,
1641 .pfn
= page_to_pfn(sg_page(s
)),
1642 .offset
= s
->offset
,
1643 .dev_addr
= sg_dma_address(s
),
1644 .size
= sg_dma_len(s
),
1645 .direction
= direction
,
1646 .sg_call_ents
= nelems
,
1650 mapped_ents
= get_nr_mapped_entries(dev
, &ref
);
1652 if (i
>= mapped_ents
)
1655 check_sync(dev
, &ref
, true);
1658 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu
);
1660 void debug_dma_sync_sg_for_device(struct device
*dev
, struct scatterlist
*sg
,
1661 int nelems
, int direction
)
1663 struct scatterlist
*s
;
1664 int mapped_ents
= 0, i
;
1666 if (unlikely(dma_debug_disabled()))
1669 for_each_sg(sg
, s
, nelems
, i
) {
1671 struct dma_debug_entry ref
= {
1672 .type
= dma_debug_sg
,
1674 .pfn
= page_to_pfn(sg_page(s
)),
1675 .offset
= s
->offset
,
1676 .dev_addr
= sg_dma_address(s
),
1677 .size
= sg_dma_len(s
),
1678 .direction
= direction
,
1679 .sg_call_ents
= nelems
,
1682 mapped_ents
= get_nr_mapped_entries(dev
, &ref
);
1684 if (i
>= mapped_ents
)
1687 check_sync(dev
, &ref
, false);
1690 EXPORT_SYMBOL(debug_dma_sync_sg_for_device
);
1692 static int __init
dma_debug_driver_setup(char *str
)
1696 for (i
= 0; i
< NAME_MAX_LEN
- 1; ++i
, ++str
) {
1697 current_driver_name
[i
] = *str
;
1702 if (current_driver_name
[0])
1703 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1704 current_driver_name
);
1709 __setup("dma_debug_driver=", dma_debug_driver_setup
);