projects/linux·blob v5.15-rc5 · refs

1589 lines · 41.1 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2008 Advanced Micro Devices, Inc.
4 *
5 * Author: Joerg Roedel <[email protected]>
6 */
7
8#define pr_fmt(fmt) "DMA-API: " fmt
9
10#include <linux/sched/task_stack.h>
11#include <linux/scatterlist.h>
12#include <linux/dma-map-ops.h>
13#include <linux/sched/task.h>
14#include <linux/stacktrace.h>
15#include <linux/spinlock.h>
16#include <linux/vmalloc.h>
17#include <linux/debugfs.h>
18#include <linux/uaccess.h>
19#include <linux/export.h>
20#include <linux/device.h>
21#include <linux/types.h>
22#include <linux/sched.h>
23#include <linux/ctype.h>
24#include <linux/list.h>
25#include <linux/slab.h>
26#include <asm/sections.h>
27#include "debug.h"
28
29#define HASH_SIZE 16384ULL
30#define HASH_FN_SHIFT 13
31#define HASH_FN_MASK (HASH_SIZE - 1)
32
33#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
34/* If the pool runs out, add this many new entries at once */
35#define DMA_DEBUG_DYNAMIC_ENTRIES (PAGE_SIZE / sizeof(struct dma_debug_entry))
36
37enum {
38 dma_debug_single,
39 dma_debug_sg,
40 dma_debug_coherent,
41 dma_debug_resource,
42};
43
44enum map_err_types {
45 MAP_ERR_CHECK_NOT_APPLICABLE,
46 MAP_ERR_NOT_CHECKED,
47 MAP_ERR_CHECKED,
48};
49
50#define DMA_DEBUG_STACKTRACE_ENTRIES 5
51
52/**
53 * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
54 * @list: node on pre-allocated free_entries list
55 * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
56 * @size: length of the mapping
57 * @type: single, page, sg, coherent
58 * @direction: enum dma_data_direction
59 * @sg_call_ents: 'nents' from dma_map_sg
60 * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
61 * @pfn: page frame of the start address
62 * @offset: offset of mapping relative to pfn
63 * @map_err_type: track whether dma_mapping_error() was checked
64 * @stacktrace: support backtraces when a violation is detected
65 */
66struct dma_debug_entry {
67 struct list_head list;
68 struct device *dev;
69 u64 dev_addr;
70 u64 size;
71 int type;
72 int direction;
73 int sg_call_ents;
74 int sg_mapped_ents;
75 unsigned long pfn;
76 size_t offset;
77 enum map_err_types map_err_type;
78#ifdef CONFIG_STACKTRACE
79 unsigned int stack_len;
80 unsigned long stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
81#endif
82} ____cacheline_aligned_in_smp;
83
84typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
85
86struct hash_bucket {
87 struct list_head list;
88 spinlock_t lock;
89};
90
91/* Hash list to save the allocated dma addresses */
92static struct hash_bucket dma_entry_hash[HASH_SIZE];
93/* List of pre-allocated dma_debug_entry's */
94static LIST_HEAD(free_entries);
95/* Lock for the list above */
96static DEFINE_SPINLOCK(free_entries_lock);
97
98/* Global disable flag - will be set in case of an error */
99static bool global_disable __read_mostly;
100
101/* Early initialization disable flag, set at the end of dma_debug_init */
102static bool dma_debug_initialized __read_mostly;
103
104static inline bool dma_debug_disabled(void)
105{
106 return global_disable || !dma_debug_initialized;
107}
108
109/* Global error count */
110static u32 error_count;
111
112/* Global error show enable*/
113static u32 show_all_errors __read_mostly;
114/* Number of errors to show */
115static u32 show_num_errors = 1;
116
117static u32 num_free_entries;
118static u32 min_free_entries;
119static u32 nr_total_entries;
120
121/* number of preallocated entries requested by kernel cmdline */
122static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
123
124/* per-driver filter related state */
125
126#define NAME_MAX_LEN 64
127
128static char current_driver_name[NAME_MAX_LEN] __read_mostly;
129static struct device_driver *current_driver __read_mostly;
130
131static DEFINE_RWLOCK(driver_name_lock);
132
133static const char *const maperr2str[] = {
134 [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
135 [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
136 [MAP_ERR_CHECKED] = "dma map error checked",
137};
138
139static const char *type2name[] = {
140 [dma_debug_single] = "single",
141 [dma_debug_sg] = "scather-gather",
142 [dma_debug_coherent] = "coherent",
143 [dma_debug_resource] = "resource",
144};
145
146static const char *dir2name[] = {
147 [DMA_BIDIRECTIONAL] = "DMA_BIDIRECTIONAL",
148 [DMA_TO_DEVICE] = "DMA_TO_DEVICE",
149 [DMA_FROM_DEVICE] = "DMA_FROM_DEVICE",
150 [DMA_NONE] = "DMA_NONE",
151};
152
153/*
154 * The access to some variables in this macro is racy. We can't use atomic_t
155 * here because all these variables are exported to debugfs. Some of them even
156 * writeable. This is also the reason why a lock won't help much. But anyway,
157 * the races are no big deal. Here is why:
158 *
159 * error_count: the addition is racy, but the worst thing that can happen is
160 * that we don't count some errors
161 * show_num_errors: the subtraction is racy. Also no big deal because in
162 * worst case this will result in one warning more in the
163 * system log than the user configured. This variable is
164 * writeable via debugfs.
165 */
166static inline void dump_entry_trace(struct dma_debug_entry *entry)
167{
168#ifdef CONFIG_STACKTRACE
169 if (entry) {
170 pr_warn("Mapped at:\n");
171 stack_trace_print(entry->stack_entries, entry->stack_len, 0);
172 }
173#endif
174}
175
176static bool driver_filter(struct device *dev)
177{
178 struct device_driver *drv;
179 unsigned long flags;
180 bool ret;
181
182 /* driver filter off */
183 if (likely(!current_driver_name[0]))
184 return true;
185
186 /* driver filter on and initialized */
187 if (current_driver && dev && dev->driver == current_driver)
188 return true;
189
190 /* driver filter on, but we can't filter on a NULL device... */
191 if (!dev)
192 return false;
193
194 if (current_driver || !current_driver_name[0])
195 return false;
196
197 /* driver filter on but not yet initialized */
198 drv = dev->driver;
199 if (!drv)
200 return false;
201
202 /* lock to protect against change of current_driver_name */
203 read_lock_irqsave(&driver_name_lock, flags);
204
205 ret = false;
206 if (drv->name &&
207 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
208 current_driver = drv;
209 ret = true;
210 }
211
212 read_unlock_irqrestore(&driver_name_lock, flags);
213
214 return ret;
215}
216
217#define err_printk(dev, entry, format, arg...) do { \
218 error_count += 1; \
219 if (driver_filter(dev) && \
220 (show_all_errors || show_num_errors > 0)) { \
221 WARN(1, pr_fmt("%s %s: ") format, \
222 dev ? dev_driver_string(dev) : "NULL", \
223 dev ? dev_name(dev) : "NULL", ## arg); \
224 dump_entry_trace(entry); \
225 } \
226 if (!show_all_errors && show_num_errors > 0) \
227 show_num_errors -= 1; \
228 } while (0);
229
230/*
231 * Hash related functions
232 *
233 * Every DMA-API request is saved into a struct dma_debug_entry. To
234 * have quick access to these structs they are stored into a hash.
235 */
236static int hash_fn(struct dma_debug_entry *entry)
237{
238 /*
239 * Hash function is based on the dma address.
240 * We use bits 20-27 here as the index into the hash
241 */
242 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
243}
244
245/*
246 * Request exclusive access to a hash bucket for a given dma_debug_entry.
247 */
248static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
249 unsigned long *flags)
250 __acquires(&dma_entry_hash[idx].lock)
251{
252 int idx = hash_fn(entry);
253 unsigned long __flags;
254
255 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
256 *flags = __flags;
257 return &dma_entry_hash[idx];
258}
259
260/*
261 * Give up exclusive access to the hash bucket
262 */
263static void put_hash_bucket(struct hash_bucket *bucket,
264 unsigned long flags)
265 __releases(&bucket->lock)
266{
267 spin_unlock_irqrestore(&bucket->lock, flags);
268}
269
270static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
271{
272 return ((a->dev_addr == b->dev_addr) &&
273 (a->dev == b->dev)) ? true : false;
274}
275
276static bool containing_match(struct dma_debug_entry *a,
277 struct dma_debug_entry *b)
278{
279 if (a->dev != b->dev)
280 return false;
281
282 if ((b->dev_addr <= a->dev_addr) &&
283 ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
284 return true;
285
286 return false;
287}
288
289/*
290 * Search a given entry in the hash bucket list
291 */
292static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
293 struct dma_debug_entry *ref,
294 match_fn match)
295{
296 struct dma_debug_entry *entry, *ret = NULL;
297 int matches = 0, match_lvl, last_lvl = -1;
298
299 list_for_each_entry(entry, &bucket->list, list) {
300 if (!match(ref, entry))
301 continue;
302
303 /*
304 * Some drivers map the same physical address multiple
305 * times. Without a hardware IOMMU this results in the
306 * same device addresses being put into the dma-debug
307 * hash multiple times too. This can result in false
308 * positives being reported. Therefore we implement a
309 * best-fit algorithm here which returns the entry from
310 * the hash which fits best to the reference value
311 * instead of the first-fit.
312 */
313 matches += 1;
314 match_lvl = 0;
315 entry->size == ref->size ? ++match_lvl : 0;
316 entry->type == ref->type ? ++match_lvl : 0;
317 entry->direction == ref->direction ? ++match_lvl : 0;
318 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
319
320 if (match_lvl == 4) {
321 /* perfect-fit - return the result */
322 return entry;
323 } else if (match_lvl > last_lvl) {
324 /*
325 * We found an entry that fits better then the
326 * previous one or it is the 1st match.
327 */
328 last_lvl = match_lvl;
329 ret = entry;
330 }
331 }
332
333 /*
334 * If we have multiple matches but no perfect-fit, just return
335 * NULL.
336 */
337 ret = (matches == 1) ? ret : NULL;
338
339 return ret;
340}
341
342static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
343 struct dma_debug_entry *ref)
344{
345 return __hash_bucket_find(bucket, ref, exact_match);
346}
347
348static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
349 struct dma_debug_entry *ref,
350 unsigned long *flags)
351{
352
353 unsigned int max_range = dma_get_max_seg_size(ref->dev);
354 struct dma_debug_entry *entry, index = *ref;
355 unsigned int range = 0;
356
357 while (range <= max_range) {
358 entry = __hash_bucket_find(*bucket, ref, containing_match);
359
360 if (entry)
361 return entry;
362
363 /*
364 * Nothing found, go back a hash bucket
365 */
366 put_hash_bucket(*bucket, *flags);
367 range += (1 << HASH_FN_SHIFT);
368 index.dev_addr -= (1 << HASH_FN_SHIFT);
369 *bucket = get_hash_bucket(&index, flags);
370 }
371
372 return NULL;
373}
374
375/*
376 * Add an entry to a hash bucket
377 */
378static void hash_bucket_add(struct hash_bucket *bucket,
379 struct dma_debug_entry *entry)
380{
381 list_add_tail(&entry->list, &bucket->list);
382}
383
384/*
385 * Remove entry from a hash bucket list
386 */
387static void hash_bucket_del(struct dma_debug_entry *entry)
388{
389 list_del(&entry->list);
390}
391
392static unsigned long long phys_addr(struct dma_debug_entry *entry)
393{
394 if (entry->type == dma_debug_resource)
395 return __pfn_to_phys(entry->pfn) + entry->offset;
396
397 return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
398}
399
400/*
401 * Dump mapping entries for debugging purposes
402 */
403void debug_dma_dump_mappings(struct device *dev)
404{
405 int idx;
406
407 for (idx = 0; idx < HASH_SIZE; idx++) {
408 struct hash_bucket *bucket = &dma_entry_hash[idx];
409 struct dma_debug_entry *entry;
410 unsigned long flags;
411
412 spin_lock_irqsave(&bucket->lock, flags);
413
414 list_for_each_entry(entry, &bucket->list, list) {
415 if (!dev || dev == entry->dev) {
416 dev_info(entry->dev,
417 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
418 type2name[entry->type], idx,
419 phys_addr(entry), entry->pfn,
420 entry->dev_addr, entry->size,
421 dir2name[entry->direction],
422 maperr2str[entry->map_err_type]);
423 }
424 }
425
426 spin_unlock_irqrestore(&bucket->lock, flags);
427 cond_resched();
428 }
429}
430
431/*
432 * For each mapping (initial cacheline in the case of
433 * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
434 * scatterlist, or the cacheline specified in dma_map_single) insert
435 * into this tree using the cacheline as the key. At
436 * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If
437 * the entry already exists at insertion time add a tag as a reference
438 * count for the overlapping mappings. For now, the overlap tracking
439 * just ensures that 'unmaps' balance 'maps' before marking the
440 * cacheline idle, but we should also be flagging overlaps as an API
441 * violation.
442 *
443 * Memory usage is mostly constrained by the maximum number of available
444 * dma-debug entries in that we need a free dma_debug_entry before
445 * inserting into the tree. In the case of dma_map_page and
446 * dma_alloc_coherent there is only one dma_debug_entry and one
447 * dma_active_cacheline entry to track per event. dma_map_sg(), on the
448 * other hand, consumes a single dma_debug_entry, but inserts 'nents'
449 * entries into the tree.
450 */
451static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
452static DEFINE_SPINLOCK(radix_lock);
453#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
454#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
455#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
456
457static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
458{
459 return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
460 (entry->offset >> L1_CACHE_SHIFT);
461}
462
463static int active_cacheline_read_overlap(phys_addr_t cln)
464{
465 int overlap = 0, i;
466
467 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
468 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
469 overlap |= 1 << i;
470 return overlap;
471}
472
473static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
474{
475 int i;
476
477 if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
478 return overlap;
479
480 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
481 if (overlap & 1 << i)
482 radix_tree_tag_set(&dma_active_cacheline, cln, i);
483 else
484 radix_tree_tag_clear(&dma_active_cacheline, cln, i);
485
486 return overlap;
487}
488
489static void active_cacheline_inc_overlap(phys_addr_t cln)
490{
491 int overlap = active_cacheline_read_overlap(cln);
492
493 overlap = active_cacheline_set_overlap(cln, ++overlap);
494
495 /* If we overflowed the overlap counter then we're potentially
496 * leaking dma-mappings.
497 */
498 WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
499 pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
500 ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
501}
502
503static int active_cacheline_dec_overlap(phys_addr_t cln)
504{
505 int overlap = active_cacheline_read_overlap(cln);
506
507 return active_cacheline_set_overlap(cln, --overlap);
508}
509
510static int active_cacheline_insert(struct dma_debug_entry *entry)
511{
512 phys_addr_t cln = to_cacheline_number(entry);
513 unsigned long flags;
514 int rc;
515
516 /* If the device is not writing memory then we don't have any
517 * concerns about the cpu consuming stale data. This mitigates
518 * legitimate usages of overlapping mappings.
519 */
520 if (entry->direction == DMA_TO_DEVICE)
521 return 0;
522
523 spin_lock_irqsave(&radix_lock, flags);
524 rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
525 if (rc == -EEXIST)
526 active_cacheline_inc_overlap(cln);
527 spin_unlock_irqrestore(&radix_lock, flags);
528
529 return rc;
530}
531
532static void active_cacheline_remove(struct dma_debug_entry *entry)
533{
534 phys_addr_t cln = to_cacheline_number(entry);
535 unsigned long flags;
536
537 /* ...mirror the insert case */
538 if (entry->direction == DMA_TO_DEVICE)
539 return;
540
541 spin_lock_irqsave(&radix_lock, flags);
542 /* since we are counting overlaps the final put of the
543 * cacheline will occur when the overlap count is 0.
544 * active_cacheline_dec_overlap() returns -1 in that case
545 */
546 if (active_cacheline_dec_overlap(cln) < 0)
547 radix_tree_delete(&dma_active_cacheline, cln);
548 spin_unlock_irqrestore(&radix_lock, flags);
549}
550
551/*
552 * Wrapper function for adding an entry to the hash.
553 * This function takes care of locking itself.
554 */
555static void add_dma_entry(struct dma_debug_entry *entry)
556{
557 struct hash_bucket *bucket;
558 unsigned long flags;
559 int rc;
560
561 bucket = get_hash_bucket(entry, &flags);
562 hash_bucket_add(bucket, entry);
563 put_hash_bucket(bucket, flags);
564
565 rc = active_cacheline_insert(entry);
566 if (rc == -ENOMEM) {
567 pr_err("cacheline tracking ENOMEM, dma-debug disabled\n");
568 global_disable = true;
569 } else if (rc == -EEXIST) {
570 err_printk(entry->dev, entry,
571 "cacheline tracking EEXIST, overlapping mappings aren't supported\n");
572 }
573}
574
575static int dma_debug_create_entries(gfp_t gfp)
576{
577 struct dma_debug_entry *entry;
578 int i;
579
580 entry = (void *)get_zeroed_page(gfp);
581 if (!entry)
582 return -ENOMEM;
583
584 for (i = 0; i < DMA_DEBUG_DYNAMIC_ENTRIES; i++)
585 list_add_tail(&entry[i].list, &free_entries);
586
587 num_free_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
588 nr_total_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
589
590 return 0;
591}
592
593static struct dma_debug_entry *__dma_entry_alloc(void)
594{
595 struct dma_debug_entry *entry;
596
597 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
598 list_del(&entry->list);
599 memset(entry, 0, sizeof(*entry));
600
601 num_free_entries -= 1;
602 if (num_free_entries < min_free_entries)
603 min_free_entries = num_free_entries;
604
605 return entry;
606}
607
608static void __dma_entry_alloc_check_leak(void)
609{
610 u32 tmp = nr_total_entries % nr_prealloc_entries;
611
612 /* Shout each time we tick over some multiple of the initial pool */
613 if (tmp < DMA_DEBUG_DYNAMIC_ENTRIES) {
614 pr_info("dma_debug_entry pool grown to %u (%u00%%)\n",
615 nr_total_entries,
616 (nr_total_entries / nr_prealloc_entries));
617 }
618}
619
620/* struct dma_entry allocator
621 *
622 * The next two functions implement the allocator for
623 * struct dma_debug_entries.
624 */
625static struct dma_debug_entry *dma_entry_alloc(void)
626{
627 struct dma_debug_entry *entry;
628 unsigned long flags;
629
630 spin_lock_irqsave(&free_entries_lock, flags);
631 if (num_free_entries == 0) {
632 if (dma_debug_create_entries(GFP_ATOMIC)) {
633 global_disable = true;
634 spin_unlock_irqrestore(&free_entries_lock, flags);
635 pr_err("debugging out of memory - disabling\n");
636 return NULL;
637 }
638 __dma_entry_alloc_check_leak();
639 }
640
641 entry = __dma_entry_alloc();
642
643 spin_unlock_irqrestore(&free_entries_lock, flags);
644
645#ifdef CONFIG_STACKTRACE
646 entry->stack_len = stack_trace_save(entry->stack_entries,
647 ARRAY_SIZE(entry->stack_entries),
648 1);
649#endif
650 return entry;
651}
652
653static void dma_entry_free(struct dma_debug_entry *entry)
654{
655 unsigned long flags;
656
657 active_cacheline_remove(entry);
658
659 /*
660 * add to beginning of the list - this way the entries are
661 * more likely cache hot when they are reallocated.
662 */
663 spin_lock_irqsave(&free_entries_lock, flags);
664 list_add(&entry->list, &free_entries);
665 num_free_entries += 1;
666 spin_unlock_irqrestore(&free_entries_lock, flags);
667}
668
669/*
670 * DMA-API debugging init code
671 *
672 * The init code does two things:
673 * 1. Initialize core data structures
674 * 2. Preallocate a given number of dma_debug_entry structs
675 */
676
677static ssize_t filter_read(struct file *file, char __user *user_buf,
678 size_t count, loff_t *ppos)
679{
680 char buf[NAME_MAX_LEN + 1];
681 unsigned long flags;
682 int len;
683
684 if (!current_driver_name[0])
685 return 0;
686
687 /*
688 * We can't copy to userspace directly because current_driver_name can
689 * only be read under the driver_name_lock with irqs disabled. So
690 * create a temporary copy first.
691 */
692 read_lock_irqsave(&driver_name_lock, flags);
693 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
694 read_unlock_irqrestore(&driver_name_lock, flags);
695
696 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
697}
698
699static ssize_t filter_write(struct file *file, const char __user *userbuf,
700 size_t count, loff_t *ppos)
701{
702 char buf[NAME_MAX_LEN];
703 unsigned long flags;
704 size_t len;
705 int i;
706
707 /*
708 * We can't copy from userspace directly. Access to
709 * current_driver_name is protected with a write_lock with irqs
710 * disabled. Since copy_from_user can fault and may sleep we
711 * need to copy to temporary buffer first
712 */
713 len = min(count, (size_t)(NAME_MAX_LEN - 1));
714 if (copy_from_user(buf, userbuf, len))
715 return -EFAULT;
716
717 buf[len] = 0;
718
719 write_lock_irqsave(&driver_name_lock, flags);
720
721 /*
722 * Now handle the string we got from userspace very carefully.
723 * The rules are:
724 * - only use the first token we got
725 * - token delimiter is everything looking like a space
726 * character (' ', '\n', '\t' ...)
727 *
728 */
729 if (!isalnum(buf[0])) {
730 /*
731 * If the first character userspace gave us is not
732 * alphanumerical then assume the filter should be
733 * switched off.
734 */
735 if (current_driver_name[0])
736 pr_info("switching off dma-debug driver filter\n");
737 current_driver_name[0] = 0;
738 current_driver = NULL;
739 goto out_unlock;
740 }
741
742 /*
743 * Now parse out the first token and use it as the name for the
744 * driver to filter for.
745 */
746 for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
747 current_driver_name[i] = buf[i];
748 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
749 break;
750 }
751 current_driver_name[i] = 0;
752 current_driver = NULL;
753
754 pr_info("enable driver filter for driver [%s]\n",
755 current_driver_name);
756
757out_unlock:
758 write_unlock_irqrestore(&driver_name_lock, flags);
759
760 return count;
761}
762
763static const struct file_operations filter_fops = {
764 .read = filter_read,
765 .write = filter_write,
766 .llseek = default_llseek,
767};
768
769static int dump_show(struct seq_file *seq, void *v)
770{
771 int idx;
772
773 for (idx = 0; idx < HASH_SIZE; idx++) {
774 struct hash_bucket *bucket = &dma_entry_hash[idx];
775 struct dma_debug_entry *entry;
776 unsigned long flags;
777
778 spin_lock_irqsave(&bucket->lock, flags);
779 list_for_each_entry(entry, &bucket->list, list) {
780 seq_printf(seq,
781 "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n",
782 dev_name(entry->dev),
783 dev_driver_string(entry->dev),
784 type2name[entry->type], idx,
785 phys_addr(entry), entry->pfn,
786 entry->dev_addr, entry->size,
787 dir2name[entry->direction],
788 maperr2str[entry->map_err_type]);
789 }
790 spin_unlock_irqrestore(&bucket->lock, flags);
791 }
792 return 0;
793}
794DEFINE_SHOW_ATTRIBUTE(dump);
795
796static int __init dma_debug_fs_init(void)
797{
798 struct dentry *dentry = debugfs_create_dir("dma-api", NULL);
799
800 debugfs_create_bool("disabled", 0444, dentry, &global_disable);
801 debugfs_create_u32("error_count", 0444, dentry, &error_count);
802 debugfs_create_u32("all_errors", 0644, dentry, &show_all_errors);
803 debugfs_create_u32("num_errors", 0644, dentry, &show_num_errors);
804 debugfs_create_u32("num_free_entries", 0444, dentry, &num_free_entries);
805 debugfs_create_u32("min_free_entries", 0444, dentry, &min_free_entries);
806 debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries);
807 debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops);
808 debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops);
809
810 return 0;
811}
812core_initcall_sync(dma_debug_fs_init);
813
814static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
815{
816 struct dma_debug_entry *entry;
817 unsigned long flags;
818 int count = 0, i;
819
820 for (i = 0; i < HASH_SIZE; ++i) {
821 spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
822 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
823 if (entry->dev == dev) {
824 count += 1;
825 *out_entry = entry;
826 }
827 }
828 spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
829 }
830
831 return count;
832}
833
834static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
835{
836 struct device *dev = data;
837 struct dma_debug_entry *entry;
838 int count;
839
840 if (dma_debug_disabled())
841 return 0;
842
843 switch (action) {
844 case BUS_NOTIFY_UNBOUND_DRIVER:
845 count = device_dma_allocations(dev, &entry);
846 if (count == 0)
847 break;
848 err_printk(dev, entry, "device driver has pending "
849 "DMA allocations while released from device "
850 "[count=%d]\n"
851 "One of leaked entries details: "
852 "[device address=0x%016llx] [size=%llu bytes] "
853 "[mapped with %s] [mapped as %s]\n",
854 count, entry->dev_addr, entry->size,
855 dir2name[entry->direction], type2name[entry->type]);
856 break;
857 default:
858 break;
859 }
860
861 return 0;
862}
863
864void dma_debug_add_bus(struct bus_type *bus)
865{
866 struct notifier_block *nb;
867
868 if (dma_debug_disabled())
869 return;
870
871 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
872 if (nb == NULL) {
873 pr_err("dma_debug_add_bus: out of memory\n");
874 return;
875 }
876
877 nb->notifier_call = dma_debug_device_change;
878
879 bus_register_notifier(bus, nb);
880}
881
882static int dma_debug_init(void)
883{
884 int i, nr_pages;
885
886 /* Do not use dma_debug_initialized here, since we really want to be
887 * called to set dma_debug_initialized
888 */
889 if (global_disable)
890 return 0;
891
892 for (i = 0; i < HASH_SIZE; ++i) {
893 INIT_LIST_HEAD(&dma_entry_hash[i].list);
894 spin_lock_init(&dma_entry_hash[i].lock);
895 }
896
897 nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES);
898 for (i = 0; i < nr_pages; ++i)
899 dma_debug_create_entries(GFP_KERNEL);
900 if (num_free_entries >= nr_prealloc_entries) {
901 pr_info("preallocated %d debug entries\n", nr_total_entries);
902 } else if (num_free_entries > 0) {
903 pr_warn("%d debug entries requested but only %d allocated\n",
904 nr_prealloc_entries, nr_total_entries);
905 } else {
906 pr_err("debugging out of memory error - disabled\n");
907 global_disable = true;
908
909 return 0;
910 }
911 min_free_entries = num_free_entries;
912
913 dma_debug_initialized = true;
914
915 pr_info("debugging enabled by kernel config\n");
916 return 0;
917}
918core_initcall(dma_debug_init);
919
920static __init int dma_debug_cmdline(char *str)
921{
922 if (!str)
923 return -EINVAL;
924
925 if (strncmp(str, "off", 3) == 0) {
926 pr_info("debugging disabled on kernel command line\n");
927 global_disable = true;
928 }
929
930 return 0;
931}
932
933static __init int dma_debug_entries_cmdline(char *str)
934{
935 if (!str)
936 return -EINVAL;
937 if (!get_option(&str, &nr_prealloc_entries))
938 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
939 return 0;
940}
941
942__setup("dma_debug=", dma_debug_cmdline);
943__setup("dma_debug_entries=", dma_debug_entries_cmdline);
944
945static void check_unmap(struct dma_debug_entry *ref)
946{
947 struct dma_debug_entry *entry;
948 struct hash_bucket *bucket;
949 unsigned long flags;
950
951 bucket = get_hash_bucket(ref, &flags);
952 entry = bucket_find_exact(bucket, ref);
953
954 if (!entry) {
955 /* must drop lock before calling dma_mapping_error */
956 put_hash_bucket(bucket, flags);
957
958 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
959 err_printk(ref->dev, NULL,
960 "device driver tries to free an "
961 "invalid DMA memory address\n");
962 } else {
963 err_printk(ref->dev, NULL,
964 "device driver tries to free DMA "
965 "memory it has not allocated [device "
966 "address=0x%016llx] [size=%llu bytes]\n",
967 ref->dev_addr, ref->size);
968 }
969 return;
970 }
971
972 if (ref->size != entry->size) {
973 err_printk(ref->dev, entry, "device driver frees "
974 "DMA memory with different size "
975 "[device address=0x%016llx] [map size=%llu bytes] "
976 "[unmap size=%llu bytes]\n",
977 ref->dev_addr, entry->size, ref->size);
978 }
979
980 if (ref->type != entry->type) {
981 err_printk(ref->dev, entry, "device driver frees "
982 "DMA memory with wrong function "
983 "[device address=0x%016llx] [size=%llu bytes] "
984 "[mapped as %s] [unmapped as %s]\n",
985 ref->dev_addr, ref->size,
986 type2name[entry->type], type2name[ref->type]);
987 } else if ((entry->type == dma_debug_coherent) &&
988 (phys_addr(ref) != phys_addr(entry))) {
989 err_printk(ref->dev, entry, "device driver frees "
990 "DMA memory with different CPU address "
991 "[device address=0x%016llx] [size=%llu bytes] "
992 "[cpu alloc address=0x%016llx] "
993 "[cpu free address=0x%016llx]",
994 ref->dev_addr, ref->size,
995 phys_addr(entry),
996 phys_addr(ref));
997 }
998
999 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1000 ref->sg_call_ents != entry->sg_call_ents) {
1001 err_printk(ref->dev, entry, "device driver frees "
1002 "DMA sg list with different entry count "
1003 "[map count=%d] [unmap count=%d]\n",
1004 entry->sg_call_ents, ref->sg_call_ents);
1005 }
1006
1007 /*
1008 * This may be no bug in reality - but most implementations of the
1009 * DMA API don't handle this properly, so check for it here
1010 */
1011 if (ref->direction != entry->direction) {
1012 err_printk(ref->dev, entry, "device driver frees "
1013 "DMA memory with different direction "
1014 "[device address=0x%016llx] [size=%llu bytes] "
1015 "[mapped with %s] [unmapped with %s]\n",
1016 ref->dev_addr, ref->size,
1017 dir2name[entry->direction],
1018 dir2name[ref->direction]);
1019 }
1020
1021 /*
1022 * Drivers should use dma_mapping_error() to check the returned
1023 * addresses of dma_map_single() and dma_map_page().
1024 * If not, print this warning message. See Documentation/core-api/dma-api.rst.
1025 */
1026 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1027 err_printk(ref->dev, entry,
1028 "device driver failed to check map error"
1029 "[device address=0x%016llx] [size=%llu bytes] "
1030 "[mapped as %s]",
1031 ref->dev_addr, ref->size,
1032 type2name[entry->type]);
1033 }
1034
1035 hash_bucket_del(entry);
1036 dma_entry_free(entry);
1037
1038 put_hash_bucket(bucket, flags);
1039}
1040
1041static void check_for_stack(struct device *dev,
1042 struct page *page, size_t offset)
1043{
1044 void *addr;
1045 struct vm_struct *stack_vm_area = task_stack_vm_area(current);
1046
1047 if (!stack_vm_area) {
1048 /* Stack is direct-mapped. */
1049 if (PageHighMem(page))
1050 return;
1051 addr = page_address(page) + offset;
1052 if (object_is_on_stack(addr))
1053 err_printk(dev, NULL, "device driver maps memory from stack [addr=%p]\n", addr);
1054 } else {
1055 /* Stack is vmalloced. */
1056 int i;
1057
1058 for (i = 0; i < stack_vm_area->nr_pages; i++) {
1059 if (page != stack_vm_area->pages[i])
1060 continue;
1061
1062 addr = (u8 *)current->stack + i * PAGE_SIZE + offset;
1063 err_printk(dev, NULL, "device driver maps memory from stack [probable addr=%p]\n", addr);
1064 break;
1065 }
1066 }
1067}
1068
1069static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1070{
1071 if (memory_intersects(_stext, _etext, addr, len) ||
1072 memory_intersects(__start_rodata, __end_rodata, addr, len))
1073 err_printk(dev, NULL, "device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1074}
1075
1076static void check_sync(struct device *dev,
1077 struct dma_debug_entry *ref,
1078 bool to_cpu)
1079{
1080 struct dma_debug_entry *entry;
1081 struct hash_bucket *bucket;
1082 unsigned long flags;
1083
1084 bucket = get_hash_bucket(ref, &flags);
1085
1086 entry = bucket_find_contain(&bucket, ref, &flags);
1087
1088 if (!entry) {
1089 err_printk(dev, NULL, "device driver tries "
1090 "to sync DMA memory it has not allocated "
1091 "[device address=0x%016llx] [size=%llu bytes]\n",
1092 (unsigned long long)ref->dev_addr, ref->size);
1093 goto out;
1094 }
1095
1096 if (ref->size > entry->size) {
1097 err_printk(dev, entry, "device driver syncs"
1098 " DMA memory outside allocated range "
1099 "[device address=0x%016llx] "
1100 "[allocation size=%llu bytes] "
1101 "[sync offset+size=%llu]\n",
1102 entry->dev_addr, entry->size,
1103 ref->size);
1104 }
1105
1106 if (entry->direction == DMA_BIDIRECTIONAL)
1107 goto out;
1108
1109 if (ref->direction != entry->direction) {
1110 err_printk(dev, entry, "device driver syncs "
1111 "DMA memory with different direction "
1112 "[device address=0x%016llx] [size=%llu bytes] "
1113 "[mapped with %s] [synced with %s]\n",
1114 (unsigned long long)ref->dev_addr, entry->size,
1115 dir2name[entry->direction],
1116 dir2name[ref->direction]);
1117 }
1118
1119 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1120 !(ref->direction == DMA_TO_DEVICE))
1121 err_printk(dev, entry, "device driver syncs "
1122 "device read-only DMA memory for cpu "
1123 "[device address=0x%016llx] [size=%llu bytes] "
1124 "[mapped with %s] [synced with %s]\n",
1125 (unsigned long long)ref->dev_addr, entry->size,
1126 dir2name[entry->direction],
1127 dir2name[ref->direction]);
1128
1129 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1130 !(ref->direction == DMA_FROM_DEVICE))
1131 err_printk(dev, entry, "device driver syncs "
1132 "device write-only DMA memory to device "
1133 "[device address=0x%016llx] [size=%llu bytes] "
1134 "[mapped with %s] [synced with %s]\n",
1135 (unsigned long long)ref->dev_addr, entry->size,
1136 dir2name[entry->direction],
1137 dir2name[ref->direction]);
1138
1139 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1140 ref->sg_call_ents != entry->sg_call_ents) {
1141 err_printk(ref->dev, entry, "device driver syncs "
1142 "DMA sg list with different entry count "
1143 "[map count=%d] [sync count=%d]\n",
1144 entry->sg_call_ents, ref->sg_call_ents);
1145 }
1146
1147out:
1148 put_hash_bucket(bucket, flags);
1149}
1150
1151static void check_sg_segment(struct device *dev, struct scatterlist *sg)
1152{
1153#ifdef CONFIG_DMA_API_DEBUG_SG
1154 unsigned int max_seg = dma_get_max_seg_size(dev);
1155 u64 start, end, boundary = dma_get_seg_boundary(dev);
1156
1157 /*
1158 * Either the driver forgot to set dma_parms appropriately, or
1159 * whoever generated the list forgot to check them.
1160 */
1161 if (sg->length > max_seg)
1162 err_printk(dev, NULL, "mapping sg segment longer than device claims to support [len=%u] [max=%u]\n",
1163 sg->length, max_seg);
1164 /*
1165 * In some cases this could potentially be the DMA API
1166 * implementation's fault, but it would usually imply that
1167 * the scatterlist was built inappropriately to begin with.
1168 */
1169 start = sg_dma_address(sg);
1170 end = start + sg_dma_len(sg) - 1;
1171 if ((start ^ end) & ~boundary)
1172 err_printk(dev, NULL, "mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n",
1173 start, end, boundary);
1174#endif
1175}
1176
1177void debug_dma_map_single(struct device *dev, const void *addr,
1178 unsigned long len)
1179{
1180 if (unlikely(dma_debug_disabled()))
1181 return;
1182
1183 if (!virt_addr_valid(addr))
1184 err_printk(dev, NULL, "device driver maps memory from invalid area [addr=%p] [len=%lu]\n",
1185 addr, len);
1186
1187 if (is_vmalloc_addr(addr))
1188 err_printk(dev, NULL, "device driver maps memory from vmalloc area [addr=%p] [len=%lu]\n",
1189 addr, len);
1190}
1191EXPORT_SYMBOL(debug_dma_map_single);
1192
1193void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1194 size_t size, int direction, dma_addr_t dma_addr)
1195{
1196 struct dma_debug_entry *entry;
1197
1198 if (unlikely(dma_debug_disabled()))
1199 return;
1200
1201 if (dma_mapping_error(dev, dma_addr))
1202 return;
1203
1204 entry = dma_entry_alloc();
1205 if (!entry)
1206 return;
1207
1208 entry->dev = dev;
1209 entry->type = dma_debug_single;
1210 entry->pfn = page_to_pfn(page);
1211 entry->offset = offset;
1212 entry->dev_addr = dma_addr;
1213 entry->size = size;
1214 entry->direction = direction;
1215 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1216
1217 check_for_stack(dev, page, offset);
1218
1219 if (!PageHighMem(page)) {
1220 void *addr = page_address(page) + offset;
1221
1222 check_for_illegal_area(dev, addr, size);
1223 }
1224
1225 add_dma_entry(entry);
1226}
1227
1228void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1229{
1230 struct dma_debug_entry ref;
1231 struct dma_debug_entry *entry;
1232 struct hash_bucket *bucket;
1233 unsigned long flags;
1234
1235 if (unlikely(dma_debug_disabled()))
1236 return;
1237
1238 ref.dev = dev;
1239 ref.dev_addr = dma_addr;
1240 bucket = get_hash_bucket(&ref, &flags);
1241
1242 list_for_each_entry(entry, &bucket->list, list) {
1243 if (!exact_match(&ref, entry))
1244 continue;
1245
1246 /*
1247 * The same physical address can be mapped multiple
1248 * times. Without a hardware IOMMU this results in the
1249 * same device addresses being put into the dma-debug
1250 * hash multiple times too. This can result in false
1251 * positives being reported. Therefore we implement a
1252 * best-fit algorithm here which updates the first entry
1253 * from the hash which fits the reference value and is
1254 * not currently listed as being checked.
1255 */
1256 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1257 entry->map_err_type = MAP_ERR_CHECKED;
1258 break;
1259 }
1260 }
1261
1262 put_hash_bucket(bucket, flags);
1263}
1264EXPORT_SYMBOL(debug_dma_mapping_error);
1265
1266void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1267 size_t size, int direction)
1268{
1269 struct dma_debug_entry ref = {
1270 .type = dma_debug_single,
1271 .dev = dev,
1272 .dev_addr = addr,
1273 .size = size,
1274 .direction = direction,
1275 };
1276
1277 if (unlikely(dma_debug_disabled()))
1278 return;
1279 check_unmap(&ref);
1280}
1281
1282void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1283 int nents, int mapped_ents, int direction)
1284{
1285 struct dma_debug_entry *entry;
1286 struct scatterlist *s;
1287 int i;
1288
1289 if (unlikely(dma_debug_disabled()))
1290 return;
1291
1292 for_each_sg(sg, s, mapped_ents, i) {
1293 entry = dma_entry_alloc();
1294 if (!entry)
1295 return;
1296
1297 entry->type = dma_debug_sg;
1298 entry->dev = dev;
1299 entry->pfn = page_to_pfn(sg_page(s));
1300 entry->offset = s->offset;
1301 entry->size = sg_dma_len(s);
1302 entry->dev_addr = sg_dma_address(s);
1303 entry->direction = direction;
1304 entry->sg_call_ents = nents;
1305 entry->sg_mapped_ents = mapped_ents;
1306
1307 check_for_stack(dev, sg_page(s), s->offset);
1308
1309 if (!PageHighMem(sg_page(s))) {
1310 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1311 }
1312
1313 check_sg_segment(dev, s);
1314
1315 add_dma_entry(entry);
1316 }
1317}
1318
1319static int get_nr_mapped_entries(struct device *dev,
1320 struct dma_debug_entry *ref)
1321{
1322 struct dma_debug_entry *entry;
1323 struct hash_bucket *bucket;
1324 unsigned long flags;
1325 int mapped_ents;
1326
1327 bucket = get_hash_bucket(ref, &flags);
1328 entry = bucket_find_exact(bucket, ref);
1329 mapped_ents = 0;
1330
1331 if (entry)
1332 mapped_ents = entry->sg_mapped_ents;
1333 put_hash_bucket(bucket, flags);
1334
1335 return mapped_ents;
1336}
1337
1338void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1339 int nelems, int dir)
1340{
1341 struct scatterlist *s;
1342 int mapped_ents = 0, i;
1343
1344 if (unlikely(dma_debug_disabled()))
1345 return;
1346
1347 for_each_sg(sglist, s, nelems, i) {
1348
1349 struct dma_debug_entry ref = {
1350 .type = dma_debug_sg,
1351 .dev = dev,
1352 .pfn = page_to_pfn(sg_page(s)),
1353 .offset = s->offset,
1354 .dev_addr = sg_dma_address(s),
1355 .size = sg_dma_len(s),
1356 .direction = dir,
1357 .sg_call_ents = nelems,
1358 };
1359
1360 if (mapped_ents && i >= mapped_ents)
1361 break;
1362
1363 if (!i)
1364 mapped_ents = get_nr_mapped_entries(dev, &ref);
1365
1366 check_unmap(&ref);
1367 }
1368}
1369
1370void debug_dma_alloc_coherent(struct device *dev, size_t size,
1371 dma_addr_t dma_addr, void *virt)
1372{
1373 struct dma_debug_entry *entry;
1374
1375 if (unlikely(dma_debug_disabled()))
1376 return;
1377
1378 if (unlikely(virt == NULL))
1379 return;
1380
1381 /* handle vmalloc and linear addresses */
1382 if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
1383 return;
1384
1385 entry = dma_entry_alloc();
1386 if (!entry)
1387 return;
1388
1389 entry->type = dma_debug_coherent;
1390 entry->dev = dev;
1391 entry->offset = offset_in_page(virt);
1392 entry->size = size;
1393 entry->dev_addr = dma_addr;
1394 entry->direction = DMA_BIDIRECTIONAL;
1395
1396 if (is_vmalloc_addr(virt))
1397 entry->pfn = vmalloc_to_pfn(virt);
1398 else
1399 entry->pfn = page_to_pfn(virt_to_page(virt));
1400
1401 add_dma_entry(entry);
1402}
1403
1404void debug_dma_free_coherent(struct device *dev, size_t size,
1405 void *virt, dma_addr_t addr)
1406{
1407 struct dma_debug_entry ref = {
1408 .type = dma_debug_coherent,
1409 .dev = dev,
1410 .offset = offset_in_page(virt),
1411 .dev_addr = addr,
1412 .size = size,
1413 .direction = DMA_BIDIRECTIONAL,
1414 };
1415
1416 /* handle vmalloc and linear addresses */
1417 if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
1418 return;
1419
1420 if (is_vmalloc_addr(virt))
1421 ref.pfn = vmalloc_to_pfn(virt);
1422 else
1423 ref.pfn = page_to_pfn(virt_to_page(virt));
1424
1425 if (unlikely(dma_debug_disabled()))
1426 return;
1427
1428 check_unmap(&ref);
1429}
1430
1431void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
1432 int direction, dma_addr_t dma_addr)
1433{
1434 struct dma_debug_entry *entry;
1435
1436 if (unlikely(dma_debug_disabled()))
1437 return;
1438
1439 entry = dma_entry_alloc();
1440 if (!entry)
1441 return;
1442
1443 entry->type = dma_debug_resource;
1444 entry->dev = dev;
1445 entry->pfn = PHYS_PFN(addr);
1446 entry->offset = offset_in_page(addr);
1447 entry->size = size;
1448 entry->dev_addr = dma_addr;
1449 entry->direction = direction;
1450 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1451
1452 add_dma_entry(entry);
1453}
1454
1455void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
1456 size_t size, int direction)
1457{
1458 struct dma_debug_entry ref = {
1459 .type = dma_debug_resource,
1460 .dev = dev,
1461 .dev_addr = dma_addr,
1462 .size = size,
1463 .direction = direction,
1464 };
1465
1466 if (unlikely(dma_debug_disabled()))
1467 return;
1468
1469 check_unmap(&ref);
1470}
1471
1472void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1473 size_t size, int direction)
1474{
1475 struct dma_debug_entry ref;
1476
1477 if (unlikely(dma_debug_disabled()))
1478 return;
1479
1480 ref.type = dma_debug_single;
1481 ref.dev = dev;
1482 ref.dev_addr = dma_handle;
1483 ref.size = size;
1484 ref.direction = direction;
1485 ref.sg_call_ents = 0;
1486
1487 check_sync(dev, &ref, true);
1488}
1489
1490void debug_dma_sync_single_for_device(struct device *dev,
1491 dma_addr_t dma_handle, size_t size,
1492 int direction)
1493{
1494 struct dma_debug_entry ref;
1495
1496 if (unlikely(dma_debug_disabled()))
1497 return;
1498
1499 ref.type = dma_debug_single;
1500 ref.dev = dev;
1501 ref.dev_addr = dma_handle;
1502 ref.size = size;
1503 ref.direction = direction;
1504 ref.sg_call_ents = 0;
1505
1506 check_sync(dev, &ref, false);
1507}
1508
1509void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1510 int nelems, int direction)
1511{
1512 struct scatterlist *s;
1513 int mapped_ents = 0, i;
1514
1515 if (unlikely(dma_debug_disabled()))
1516 return;
1517
1518 for_each_sg(sg, s, nelems, i) {
1519
1520 struct dma_debug_entry ref = {
1521 .type = dma_debug_sg,
1522 .dev = dev,
1523 .pfn = page_to_pfn(sg_page(s)),
1524 .offset = s->offset,
1525 .dev_addr = sg_dma_address(s),
1526 .size = sg_dma_len(s),
1527 .direction = direction,
1528 .sg_call_ents = nelems,
1529 };
1530
1531 if (!i)
1532 mapped_ents = get_nr_mapped_entries(dev, &ref);
1533
1534 if (i >= mapped_ents)
1535 break;
1536
1537 check_sync(dev, &ref, true);
1538 }
1539}
1540
1541void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1542 int nelems, int direction)
1543{
1544 struct scatterlist *s;
1545 int mapped_ents = 0, i;
1546
1547 if (unlikely(dma_debug_disabled()))
1548 return;
1549
1550 for_each_sg(sg, s, nelems, i) {
1551
1552 struct dma_debug_entry ref = {
1553 .type = dma_debug_sg,
1554 .dev = dev,
1555 .pfn = page_to_pfn(sg_page(s)),
1556 .offset = s->offset,
1557 .dev_addr = sg_dma_address(s),
1558 .size = sg_dma_len(s),
1559 .direction = direction,
1560 .sg_call_ents = nelems,
1561 };
1562 if (!i)
1563 mapped_ents = get_nr_mapped_entries(dev, &ref);
1564
1565 if (i >= mapped_ents)
1566 break;
1567
1568 check_sync(dev, &ref, false);
1569 }
1570}
1571
1572static int __init dma_debug_driver_setup(char *str)
1573{
1574 int i;
1575
1576 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1577 current_driver_name[i] = *str;
1578 if (*str == 0)
1579 break;
1580 }
1581
1582 if (current_driver_name[0])
1583 pr_info("enable driver filter for driver [%s]\n",
1584 current_driver_name);
1585
1586
1587 return 1;
1588}
1589__setup("dma_debug_driver=", dma_debug_driver_setup);