projects/linux·blob v6.6 · refs

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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 * @dev_addr: dma address
57 * @size: length of the mapping
58 * @type: single, page, sg, coherent
59 * @direction: enum dma_data_direction
60 * @sg_call_ents: 'nents' from dma_map_sg
61 * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
62 * @pfn: page frame of the start address
63 * @offset: offset of mapping relative to pfn
64 * @map_err_type: track whether dma_mapping_error() was checked
65 * @stacktrace: support backtraces when a violation is detected
66 */
67struct dma_debug_entry {
68 struct list_head list;
69 struct device *dev;
70 u64 dev_addr;
71 u64 size;
72 int type;
73 int direction;
74 int sg_call_ents;
75 int sg_mapped_ents;
76 unsigned long pfn;
77 size_t offset;
78 enum map_err_types map_err_type;
79#ifdef CONFIG_STACKTRACE
80 unsigned int stack_len;
81 unsigned long stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
82#endif
83} ____cacheline_aligned_in_smp;
84
85typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
86
87struct hash_bucket {
88 struct list_head list;
89 spinlock_t lock;
90};
91
92/* Hash list to save the allocated dma addresses */
93static struct hash_bucket dma_entry_hash[HASH_SIZE];
94/* List of pre-allocated dma_debug_entry's */
95static LIST_HEAD(free_entries);
96/* Lock for the list above */
97static DEFINE_SPINLOCK(free_entries_lock);
98
99/* Global disable flag - will be set in case of an error */
100static bool global_disable __read_mostly;
101
102/* Early initialization disable flag, set at the end of dma_debug_init */
103static bool dma_debug_initialized __read_mostly;
104
105static inline bool dma_debug_disabled(void)
106{
107 return global_disable || !dma_debug_initialized;
108}
109
110/* Global error count */
111static u32 error_count;
112
113/* Global error show enable*/
114static u32 show_all_errors __read_mostly;
115/* Number of errors to show */
116static u32 show_num_errors = 1;
117
118static u32 num_free_entries;
119static u32 min_free_entries;
120static u32 nr_total_entries;
121
122/* number of preallocated entries requested by kernel cmdline */
123static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
124
125/* per-driver filter related state */
126
127#define NAME_MAX_LEN 64
128
129static char current_driver_name[NAME_MAX_LEN] __read_mostly;
130static struct device_driver *current_driver __read_mostly;
131
132static DEFINE_RWLOCK(driver_name_lock);
133
134static const char *const maperr2str[] = {
135 [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
136 [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
137 [MAP_ERR_CHECKED] = "dma map error checked",
138};
139
140static const char *type2name[] = {
141 [dma_debug_single] = "single",
142 [dma_debug_sg] = "scather-gather",
143 [dma_debug_coherent] = "coherent",
144 [dma_debug_resource] = "resource",
145};
146
147static const char *dir2name[] = {
148 [DMA_BIDIRECTIONAL] = "DMA_BIDIRECTIONAL",
149 [DMA_TO_DEVICE] = "DMA_TO_DEVICE",
150 [DMA_FROM_DEVICE] = "DMA_FROM_DEVICE",
151 [DMA_NONE] = "DMA_NONE",
152};
153
154/*
155 * The access to some variables in this macro is racy. We can't use atomic_t
156 * here because all these variables are exported to debugfs. Some of them even
157 * writeable. This is also the reason why a lock won't help much. But anyway,
158 * the races are no big deal. Here is why:
159 *
160 * error_count: the addition is racy, but the worst thing that can happen is
161 * that we don't count some errors
162 * show_num_errors: the subtraction is racy. Also no big deal because in
163 * worst case this will result in one warning more in the
164 * system log than the user configured. This variable is
165 * writeable via debugfs.
166 */
167static inline void dump_entry_trace(struct dma_debug_entry *entry)
168{
169#ifdef CONFIG_STACKTRACE
170 if (entry) {
171 pr_warn("Mapped at:\n");
172 stack_trace_print(entry->stack_entries, entry->stack_len, 0);
173 }
174#endif
175}
176
177static bool driver_filter(struct device *dev)
178{
179 struct device_driver *drv;
180 unsigned long flags;
181 bool ret;
182
183 /* driver filter off */
184 if (likely(!current_driver_name[0]))
185 return true;
186
187 /* driver filter on and initialized */
188 if (current_driver && dev && dev->driver == current_driver)
189 return true;
190
191 /* driver filter on, but we can't filter on a NULL device... */
192 if (!dev)
193 return false;
194
195 if (current_driver || !current_driver_name[0])
196 return false;
197
198 /* driver filter on but not yet initialized */
199 drv = dev->driver;
200 if (!drv)
201 return false;
202
203 /* lock to protect against change of current_driver_name */
204 read_lock_irqsave(&driver_name_lock, flags);
205
206 ret = false;
207 if (drv->name &&
208 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
209 current_driver = drv;
210 ret = true;
211 }
212
213 read_unlock_irqrestore(&driver_name_lock, flags);
214
215 return ret;
216}
217
218#define err_printk(dev, entry, format, arg...) do { \
219 error_count += 1; \
220 if (driver_filter(dev) && \
221 (show_all_errors || show_num_errors > 0)) { \
222 WARN(1, pr_fmt("%s %s: ") format, \
223 dev ? dev_driver_string(dev) : "NULL", \
224 dev ? dev_name(dev) : "NULL", ## arg); \
225 dump_entry_trace(entry); \
226 } \
227 if (!show_all_errors && show_num_errors > 0) \
228 show_num_errors -= 1; \
229 } while (0);
230
231/*
232 * Hash related functions
233 *
234 * Every DMA-API request is saved into a struct dma_debug_entry. To
235 * have quick access to these structs they are stored into a hash.
236 */
237static int hash_fn(struct dma_debug_entry *entry)
238{
239 /*
240 * Hash function is based on the dma address.
241 * We use bits 20-27 here as the index into the hash
242 */
243 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
244}
245
246/*
247 * Request exclusive access to a hash bucket for a given dma_debug_entry.
248 */
249static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
250 unsigned long *flags)
251 __acquires(&dma_entry_hash[idx].lock)
252{
253 int idx = hash_fn(entry);
254 unsigned long __flags;
255
256 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
257 *flags = __flags;
258 return &dma_entry_hash[idx];
259}
260
261/*
262 * Give up exclusive access to the hash bucket
263 */
264static void put_hash_bucket(struct hash_bucket *bucket,
265 unsigned long flags)
266 __releases(&bucket->lock)
267{
268 spin_unlock_irqrestore(&bucket->lock, flags);
269}
270
271static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
272{
273 return ((a->dev_addr == b->dev_addr) &&
274 (a->dev == b->dev)) ? true : false;
275}
276
277static bool containing_match(struct dma_debug_entry *a,
278 struct dma_debug_entry *b)
279{
280 if (a->dev != b->dev)
281 return false;
282
283 if ((b->dev_addr <= a->dev_addr) &&
284 ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
285 return true;
286
287 return false;
288}
289
290/*
291 * Search a given entry in the hash bucket list
292 */
293static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
294 struct dma_debug_entry *ref,
295 match_fn match)
296{
297 struct dma_debug_entry *entry, *ret = NULL;
298 int matches = 0, match_lvl, last_lvl = -1;
299
300 list_for_each_entry(entry, &bucket->list, list) {
301 if (!match(ref, entry))
302 continue;
303
304 /*
305 * Some drivers map the same physical address multiple
306 * times. Without a hardware IOMMU this results in the
307 * same device addresses being put into the dma-debug
308 * hash multiple times too. This can result in false
309 * positives being reported. Therefore we implement a
310 * best-fit algorithm here which returns the entry from
311 * the hash which fits best to the reference value
312 * instead of the first-fit.
313 */
314 matches += 1;
315 match_lvl = 0;
316 entry->size == ref->size ? ++match_lvl : 0;
317 entry->type == ref->type ? ++match_lvl : 0;
318 entry->direction == ref->direction ? ++match_lvl : 0;
319 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
320
321 if (match_lvl == 4) {
322 /* perfect-fit - return the result */
323 return entry;
324 } else if (match_lvl > last_lvl) {
325 /*
326 * We found an entry that fits better then the
327 * previous one or it is the 1st match.
328 */
329 last_lvl = match_lvl;
330 ret = entry;
331 }
332 }
333
334 /*
335 * If we have multiple matches but no perfect-fit, just return
336 * NULL.
337 */
338 ret = (matches == 1) ? ret : NULL;
339
340 return ret;
341}
342
343static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
344 struct dma_debug_entry *ref)
345{
346 return __hash_bucket_find(bucket, ref, exact_match);
347}
348
349static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
350 struct dma_debug_entry *ref,
351 unsigned long *flags)
352{
353
354 struct dma_debug_entry *entry, index = *ref;
355 int limit = min(HASH_SIZE, (index.dev_addr >> HASH_FN_SHIFT) + 1);
356
357 for (int i = 0; i < limit; i++) {
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 index.dev_addr -= (1 << HASH_FN_SHIFT);
368 *bucket = get_hash_bucket(&index, flags);
369 }
370
371 return NULL;
372}
373
374/*
375 * Add an entry to a hash bucket
376 */
377static void hash_bucket_add(struct hash_bucket *bucket,
378 struct dma_debug_entry *entry)
379{
380 list_add_tail(&entry->list, &bucket->list);
381}
382
383/*
384 * Remove entry from a hash bucket list
385 */
386static void hash_bucket_del(struct dma_debug_entry *entry)
387{
388 list_del(&entry->list);
389}
390
391static unsigned long long phys_addr(struct dma_debug_entry *entry)
392{
393 if (entry->type == dma_debug_resource)
394 return __pfn_to_phys(entry->pfn) + entry->offset;
395
396 return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
397}
398
399/*
400 * For each mapping (initial cacheline in the case of
401 * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
402 * scatterlist, or the cacheline specified in dma_map_single) insert
403 * into this tree using the cacheline as the key. At
404 * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If
405 * the entry already exists at insertion time add a tag as a reference
406 * count for the overlapping mappings. For now, the overlap tracking
407 * just ensures that 'unmaps' balance 'maps' before marking the
408 * cacheline idle, but we should also be flagging overlaps as an API
409 * violation.
410 *
411 * Memory usage is mostly constrained by the maximum number of available
412 * dma-debug entries in that we need a free dma_debug_entry before
413 * inserting into the tree. In the case of dma_map_page and
414 * dma_alloc_coherent there is only one dma_debug_entry and one
415 * dma_active_cacheline entry to track per event. dma_map_sg(), on the
416 * other hand, consumes a single dma_debug_entry, but inserts 'nents'
417 * entries into the tree.
418 */
419static RADIX_TREE(dma_active_cacheline, GFP_ATOMIC);
420static DEFINE_SPINLOCK(radix_lock);
421#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
422#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
423#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
424
425static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
426{
427 return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
428 (entry->offset >> L1_CACHE_SHIFT);
429}
430
431static int active_cacheline_read_overlap(phys_addr_t cln)
432{
433 int overlap = 0, i;
434
435 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
436 if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
437 overlap |= 1 << i;
438 return overlap;
439}
440
441static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
442{
443 int i;
444
445 if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
446 return overlap;
447
448 for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
449 if (overlap & 1 << i)
450 radix_tree_tag_set(&dma_active_cacheline, cln, i);
451 else
452 radix_tree_tag_clear(&dma_active_cacheline, cln, i);
453
454 return overlap;
455}
456
457static void active_cacheline_inc_overlap(phys_addr_t cln)
458{
459 int overlap = active_cacheline_read_overlap(cln);
460
461 overlap = active_cacheline_set_overlap(cln, ++overlap);
462
463 /* If we overflowed the overlap counter then we're potentially
464 * leaking dma-mappings.
465 */
466 WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
467 pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
468 ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
469}
470
471static int active_cacheline_dec_overlap(phys_addr_t cln)
472{
473 int overlap = active_cacheline_read_overlap(cln);
474
475 return active_cacheline_set_overlap(cln, --overlap);
476}
477
478static int active_cacheline_insert(struct dma_debug_entry *entry)
479{
480 phys_addr_t cln = to_cacheline_number(entry);
481 unsigned long flags;
482 int rc;
483
484 /* If the device is not writing memory then we don't have any
485 * concerns about the cpu consuming stale data. This mitigates
486 * legitimate usages of overlapping mappings.
487 */
488 if (entry->direction == DMA_TO_DEVICE)
489 return 0;
490
491 spin_lock_irqsave(&radix_lock, flags);
492 rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
493 if (rc == -EEXIST)
494 active_cacheline_inc_overlap(cln);
495 spin_unlock_irqrestore(&radix_lock, flags);
496
497 return rc;
498}
499
500static void active_cacheline_remove(struct dma_debug_entry *entry)
501{
502 phys_addr_t cln = to_cacheline_number(entry);
503 unsigned long flags;
504
505 /* ...mirror the insert case */
506 if (entry->direction == DMA_TO_DEVICE)
507 return;
508
509 spin_lock_irqsave(&radix_lock, flags);
510 /* since we are counting overlaps the final put of the
511 * cacheline will occur when the overlap count is 0.
512 * active_cacheline_dec_overlap() returns -1 in that case
513 */
514 if (active_cacheline_dec_overlap(cln) < 0)
515 radix_tree_delete(&dma_active_cacheline, cln);
516 spin_unlock_irqrestore(&radix_lock, flags);
517}
518
519/*
520 * Dump mappings entries on kernel space for debugging purposes
521 */
522void debug_dma_dump_mappings(struct device *dev)
523{
524 int idx;
525 phys_addr_t cln;
526
527 for (idx = 0; idx < HASH_SIZE; idx++) {
528 struct hash_bucket *bucket = &dma_entry_hash[idx];
529 struct dma_debug_entry *entry;
530 unsigned long flags;
531
532 spin_lock_irqsave(&bucket->lock, flags);
533 list_for_each_entry(entry, &bucket->list, list) {
534 if (!dev || dev == entry->dev) {
535 cln = to_cacheline_number(entry);
536 dev_info(entry->dev,
537 "%s idx %d P=%llx N=%lx D=%llx L=%llx cln=%pa %s %s\n",
538 type2name[entry->type], idx,
539 phys_addr(entry), entry->pfn,
540 entry->dev_addr, entry->size,
541 &cln, dir2name[entry->direction],
542 maperr2str[entry->map_err_type]);
543 }
544 }
545 spin_unlock_irqrestore(&bucket->lock, flags);
546
547 cond_resched();
548 }
549}
550
551/*
552 * Dump mappings entries on user space via debugfs
553 */
554static int dump_show(struct seq_file *seq, void *v)
555{
556 int idx;
557 phys_addr_t cln;
558
559 for (idx = 0; idx < HASH_SIZE; idx++) {
560 struct hash_bucket *bucket = &dma_entry_hash[idx];
561 struct dma_debug_entry *entry;
562 unsigned long flags;
563
564 spin_lock_irqsave(&bucket->lock, flags);
565 list_for_each_entry(entry, &bucket->list, list) {
566 cln = to_cacheline_number(entry);
567 seq_printf(seq,
568 "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx cln=%pa %s %s\n",
569 dev_driver_string(entry->dev),
570 dev_name(entry->dev),
571 type2name[entry->type], idx,
572 phys_addr(entry), entry->pfn,
573 entry->dev_addr, entry->size,
574 &cln, dir2name[entry->direction],
575 maperr2str[entry->map_err_type]);
576 }
577 spin_unlock_irqrestore(&bucket->lock, flags);
578 }
579 return 0;
580}
581DEFINE_SHOW_ATTRIBUTE(dump);
582
583/*
584 * Wrapper function for adding an entry to the hash.
585 * This function takes care of locking itself.
586 */
587static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
588{
589 struct hash_bucket *bucket;
590 unsigned long flags;
591 int rc;
592
593 bucket = get_hash_bucket(entry, &flags);
594 hash_bucket_add(bucket, entry);
595 put_hash_bucket(bucket, flags);
596
597 rc = active_cacheline_insert(entry);
598 if (rc == -ENOMEM) {
599 pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n");
600 global_disable = true;
601 } else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
602 err_printk(entry->dev, entry,
603 "cacheline tracking EEXIST, overlapping mappings aren't supported\n");
604 }
605}
606
607static int dma_debug_create_entries(gfp_t gfp)
608{
609 struct dma_debug_entry *entry;
610 int i;
611
612 entry = (void *)get_zeroed_page(gfp);
613 if (!entry)
614 return -ENOMEM;
615
616 for (i = 0; i < DMA_DEBUG_DYNAMIC_ENTRIES; i++)
617 list_add_tail(&entry[i].list, &free_entries);
618
619 num_free_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
620 nr_total_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
621
622 return 0;
623}
624
625static struct dma_debug_entry *__dma_entry_alloc(void)
626{
627 struct dma_debug_entry *entry;
628
629 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
630 list_del(&entry->list);
631 memset(entry, 0, sizeof(*entry));
632
633 num_free_entries -= 1;
634 if (num_free_entries < min_free_entries)
635 min_free_entries = num_free_entries;
636
637 return entry;
638}
639
640/*
641 * This should be called outside of free_entries_lock scope to avoid potential
642 * deadlocks with serial consoles that use DMA.
643 */
644static void __dma_entry_alloc_check_leak(u32 nr_entries)
645{
646 u32 tmp = nr_entries % nr_prealloc_entries;
647
648 /* Shout each time we tick over some multiple of the initial pool */
649 if (tmp < DMA_DEBUG_DYNAMIC_ENTRIES) {
650 pr_info("dma_debug_entry pool grown to %u (%u00%%)\n",
651 nr_entries,
652 (nr_entries / nr_prealloc_entries));
653 }
654}
655
656/* struct dma_entry allocator
657 *
658 * The next two functions implement the allocator for
659 * struct dma_debug_entries.
660 */
661static struct dma_debug_entry *dma_entry_alloc(void)
662{
663 bool alloc_check_leak = false;
664 struct dma_debug_entry *entry;
665 unsigned long flags;
666 u32 nr_entries;
667
668 spin_lock_irqsave(&free_entries_lock, flags);
669 if (num_free_entries == 0) {
670 if (dma_debug_create_entries(GFP_ATOMIC)) {
671 global_disable = true;
672 spin_unlock_irqrestore(&free_entries_lock, flags);
673 pr_err("debugging out of memory - disabling\n");
674 return NULL;
675 }
676 alloc_check_leak = true;
677 nr_entries = nr_total_entries;
678 }
679
680 entry = __dma_entry_alloc();
681
682 spin_unlock_irqrestore(&free_entries_lock, flags);
683
684 if (alloc_check_leak)
685 __dma_entry_alloc_check_leak(nr_entries);
686
687#ifdef CONFIG_STACKTRACE
688 entry->stack_len = stack_trace_save(entry->stack_entries,
689 ARRAY_SIZE(entry->stack_entries),
690 1);
691#endif
692 return entry;
693}
694
695static void dma_entry_free(struct dma_debug_entry *entry)
696{
697 unsigned long flags;
698
699 active_cacheline_remove(entry);
700
701 /*
702 * add to beginning of the list - this way the entries are
703 * more likely cache hot when they are reallocated.
704 */
705 spin_lock_irqsave(&free_entries_lock, flags);
706 list_add(&entry->list, &free_entries);
707 num_free_entries += 1;
708 spin_unlock_irqrestore(&free_entries_lock, flags);
709}
710
711/*
712 * DMA-API debugging init code
713 *
714 * The init code does two things:
715 * 1. Initialize core data structures
716 * 2. Preallocate a given number of dma_debug_entry structs
717 */
718
719static ssize_t filter_read(struct file *file, char __user *user_buf,
720 size_t count, loff_t *ppos)
721{
722 char buf[NAME_MAX_LEN + 1];
723 unsigned long flags;
724 int len;
725
726 if (!current_driver_name[0])
727 return 0;
728
729 /*
730 * We can't copy to userspace directly because current_driver_name can
731 * only be read under the driver_name_lock with irqs disabled. So
732 * create a temporary copy first.
733 */
734 read_lock_irqsave(&driver_name_lock, flags);
735 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
736 read_unlock_irqrestore(&driver_name_lock, flags);
737
738 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
739}
740
741static ssize_t filter_write(struct file *file, const char __user *userbuf,
742 size_t count, loff_t *ppos)
743{
744 char buf[NAME_MAX_LEN];
745 unsigned long flags;
746 size_t len;
747 int i;
748
749 /*
750 * We can't copy from userspace directly. Access to
751 * current_driver_name is protected with a write_lock with irqs
752 * disabled. Since copy_from_user can fault and may sleep we
753 * need to copy to temporary buffer first
754 */
755 len = min(count, (size_t)(NAME_MAX_LEN - 1));
756 if (copy_from_user(buf, userbuf, len))
757 return -EFAULT;
758
759 buf[len] = 0;
760
761 write_lock_irqsave(&driver_name_lock, flags);
762
763 /*
764 * Now handle the string we got from userspace very carefully.
765 * The rules are:
766 * - only use the first token we got
767 * - token delimiter is everything looking like a space
768 * character (' ', '\n', '\t' ...)
769 *
770 */
771 if (!isalnum(buf[0])) {
772 /*
773 * If the first character userspace gave us is not
774 * alphanumerical then assume the filter should be
775 * switched off.
776 */
777 if (current_driver_name[0])
778 pr_info("switching off dma-debug driver filter\n");
779 current_driver_name[0] = 0;
780 current_driver = NULL;
781 goto out_unlock;
782 }
783
784 /*
785 * Now parse out the first token and use it as the name for the
786 * driver to filter for.
787 */
788 for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
789 current_driver_name[i] = buf[i];
790 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
791 break;
792 }
793 current_driver_name[i] = 0;
794 current_driver = NULL;
795
796 pr_info("enable driver filter for driver [%s]\n",
797 current_driver_name);
798
799out_unlock:
800 write_unlock_irqrestore(&driver_name_lock, flags);
801
802 return count;
803}
804
805static const struct file_operations filter_fops = {
806 .read = filter_read,
807 .write = filter_write,
808 .llseek = default_llseek,
809};
810
811static int __init dma_debug_fs_init(void)
812{
813 struct dentry *dentry = debugfs_create_dir("dma-api", NULL);
814
815 debugfs_create_bool("disabled", 0444, dentry, &global_disable);
816 debugfs_create_u32("error_count", 0444, dentry, &error_count);
817 debugfs_create_u32("all_errors", 0644, dentry, &show_all_errors);
818 debugfs_create_u32("num_errors", 0644, dentry, &show_num_errors);
819 debugfs_create_u32("num_free_entries", 0444, dentry, &num_free_entries);
820 debugfs_create_u32("min_free_entries", 0444, dentry, &min_free_entries);
821 debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries);
822 debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops);
823 debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops);
824
825 return 0;
826}
827core_initcall_sync(dma_debug_fs_init);
828
829static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
830{
831 struct dma_debug_entry *entry;
832 unsigned long flags;
833 int count = 0, i;
834
835 for (i = 0; i < HASH_SIZE; ++i) {
836 spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
837 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
838 if (entry->dev == dev) {
839 count += 1;
840 *out_entry = entry;
841 }
842 }
843 spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
844 }
845
846 return count;
847}
848
849static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
850{
851 struct device *dev = data;
852 struct dma_debug_entry *entry;
853 int count;
854
855 if (dma_debug_disabled())
856 return 0;
857
858 switch (action) {
859 case BUS_NOTIFY_UNBOUND_DRIVER:
860 count = device_dma_allocations(dev, &entry);
861 if (count == 0)
862 break;
863 err_printk(dev, entry, "device driver has pending "
864 "DMA allocations while released from device "
865 "[count=%d]\n"
866 "One of leaked entries details: "
867 "[device address=0x%016llx] [size=%llu bytes] "
868 "[mapped with %s] [mapped as %s]\n",
869 count, entry->dev_addr, entry->size,
870 dir2name[entry->direction], type2name[entry->type]);
871 break;
872 default:
873 break;
874 }
875
876 return 0;
877}
878
879void dma_debug_add_bus(struct bus_type *bus)
880{
881 struct notifier_block *nb;
882
883 if (dma_debug_disabled())
884 return;
885
886 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
887 if (nb == NULL) {
888 pr_err("dma_debug_add_bus: out of memory\n");
889 return;
890 }
891
892 nb->notifier_call = dma_debug_device_change;
893
894 bus_register_notifier(bus, nb);
895}
896
897static int dma_debug_init(void)
898{
899 int i, nr_pages;
900
901 /* Do not use dma_debug_initialized here, since we really want to be
902 * called to set dma_debug_initialized
903 */
904 if (global_disable)
905 return 0;
906
907 for (i = 0; i < HASH_SIZE; ++i) {
908 INIT_LIST_HEAD(&dma_entry_hash[i].list);
909 spin_lock_init(&dma_entry_hash[i].lock);
910 }
911
912 nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES);
913 for (i = 0; i < nr_pages; ++i)
914 dma_debug_create_entries(GFP_KERNEL);
915 if (num_free_entries >= nr_prealloc_entries) {
916 pr_info("preallocated %d debug entries\n", nr_total_entries);
917 } else if (num_free_entries > 0) {
918 pr_warn("%d debug entries requested but only %d allocated\n",
919 nr_prealloc_entries, nr_total_entries);
920 } else {
921 pr_err("debugging out of memory error - disabled\n");
922 global_disable = true;
923
924 return 0;
925 }
926 min_free_entries = num_free_entries;
927
928 dma_debug_initialized = true;
929
930 pr_info("debugging enabled by kernel config\n");
931 return 0;
932}
933core_initcall(dma_debug_init);
934
935static __init int dma_debug_cmdline(char *str)
936{
937 if (!str)
938 return -EINVAL;
939
940 if (strncmp(str, "off", 3) == 0) {
941 pr_info("debugging disabled on kernel command line\n");
942 global_disable = true;
943 }
944
945 return 1;
946}
947
948static __init int dma_debug_entries_cmdline(char *str)
949{
950 if (!str)
951 return -EINVAL;
952 if (!get_option(&str, &nr_prealloc_entries))
953 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
954 return 1;
955}
956
957__setup("dma_debug=", dma_debug_cmdline);
958__setup("dma_debug_entries=", dma_debug_entries_cmdline);
959
960static void check_unmap(struct dma_debug_entry *ref)
961{
962 struct dma_debug_entry *entry;
963 struct hash_bucket *bucket;
964 unsigned long flags;
965
966 bucket = get_hash_bucket(ref, &flags);
967 entry = bucket_find_exact(bucket, ref);
968
969 if (!entry) {
970 /* must drop lock before calling dma_mapping_error */
971 put_hash_bucket(bucket, flags);
972
973 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
974 err_printk(ref->dev, NULL,
975 "device driver tries to free an "
976 "invalid DMA memory address\n");
977 } else {
978 err_printk(ref->dev, NULL,
979 "device driver tries to free DMA "
980 "memory it has not allocated [device "
981 "address=0x%016llx] [size=%llu bytes]\n",
982 ref->dev_addr, ref->size);
983 }
984 return;
985 }
986
987 if (ref->size != entry->size) {
988 err_printk(ref->dev, entry, "device driver frees "
989 "DMA memory with different size "
990 "[device address=0x%016llx] [map size=%llu bytes] "
991 "[unmap size=%llu bytes]\n",
992 ref->dev_addr, entry->size, ref->size);
993 }
994
995 if (ref->type != entry->type) {
996 err_printk(ref->dev, entry, "device driver frees "
997 "DMA memory with wrong function "
998 "[device address=0x%016llx] [size=%llu bytes] "
999 "[mapped as %s] [unmapped as %s]\n",
1000 ref->dev_addr, ref->size,
1001 type2name[entry->type], type2name[ref->type]);
1002 } else if ((entry->type == dma_debug_coherent) &&
1003 (phys_addr(ref) != phys_addr(entry))) {
1004 err_printk(ref->dev, entry, "device driver frees "
1005 "DMA memory with different CPU address "
1006 "[device address=0x%016llx] [size=%llu bytes] "
1007 "[cpu alloc address=0x%016llx] "
1008 "[cpu free address=0x%016llx]",
1009 ref->dev_addr, ref->size,
1010 phys_addr(entry),
1011 phys_addr(ref));
1012 }
1013
1014 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1015 ref->sg_call_ents != entry->sg_call_ents) {
1016 err_printk(ref->dev, entry, "device driver frees "
1017 "DMA sg list with different entry count "
1018 "[map count=%d] [unmap count=%d]\n",
1019 entry->sg_call_ents, ref->sg_call_ents);
1020 }
1021
1022 /*
1023 * This may be no bug in reality - but most implementations of the
1024 * DMA API don't handle this properly, so check for it here
1025 */
1026 if (ref->direction != entry->direction) {
1027 err_printk(ref->dev, entry, "device driver frees "
1028 "DMA memory with different direction "
1029 "[device address=0x%016llx] [size=%llu bytes] "
1030 "[mapped with %s] [unmapped with %s]\n",
1031 ref->dev_addr, ref->size,
1032 dir2name[entry->direction],
1033 dir2name[ref->direction]);
1034 }
1035
1036 /*
1037 * Drivers should use dma_mapping_error() to check the returned
1038 * addresses of dma_map_single() and dma_map_page().
1039 * If not, print this warning message. See Documentation/core-api/dma-api.rst.
1040 */
1041 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1042 err_printk(ref->dev, entry,
1043 "device driver failed to check map error"
1044 "[device address=0x%016llx] [size=%llu bytes] "
1045 "[mapped as %s]",
1046 ref->dev_addr, ref->size,
1047 type2name[entry->type]);
1048 }
1049
1050 hash_bucket_del(entry);
1051 dma_entry_free(entry);
1052
1053 put_hash_bucket(bucket, flags);
1054}
1055
1056static void check_for_stack(struct device *dev,
1057 struct page *page, size_t offset)
1058{
1059 void *addr;
1060 struct vm_struct *stack_vm_area = task_stack_vm_area(current);
1061
1062 if (!stack_vm_area) {
1063 /* Stack is direct-mapped. */
1064 if (PageHighMem(page))
1065 return;
1066 addr = page_address(page) + offset;
1067 if (object_is_on_stack(addr))
1068 err_printk(dev, NULL, "device driver maps memory from stack [addr=%p]\n", addr);
1069 } else {
1070 /* Stack is vmalloced. */
1071 int i;
1072
1073 for (i = 0; i < stack_vm_area->nr_pages; i++) {
1074 if (page != stack_vm_area->pages[i])
1075 continue;
1076
1077 addr = (u8 *)current->stack + i * PAGE_SIZE + offset;
1078 err_printk(dev, NULL, "device driver maps memory from stack [probable addr=%p]\n", addr);
1079 break;
1080 }
1081 }
1082}
1083
1084static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1085{
1086 if (memory_intersects(_stext, _etext, addr, len) ||
1087 memory_intersects(__start_rodata, __end_rodata, addr, len))
1088 err_printk(dev, NULL, "device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1089}
1090
1091static void check_sync(struct device *dev,
1092 struct dma_debug_entry *ref,
1093 bool to_cpu)
1094{
1095 struct dma_debug_entry *entry;
1096 struct hash_bucket *bucket;
1097 unsigned long flags;
1098
1099 bucket = get_hash_bucket(ref, &flags);
1100
1101 entry = bucket_find_contain(&bucket, ref, &flags);
1102
1103 if (!entry) {
1104 err_printk(dev, NULL, "device driver tries "
1105 "to sync DMA memory it has not allocated "
1106 "[device address=0x%016llx] [size=%llu bytes]\n",
1107 (unsigned long long)ref->dev_addr, ref->size);
1108 goto out;
1109 }
1110
1111 if (ref->size > entry->size) {
1112 err_printk(dev, entry, "device driver syncs"
1113 " DMA memory outside allocated range "
1114 "[device address=0x%016llx] "
1115 "[allocation size=%llu bytes] "
1116 "[sync offset+size=%llu]\n",
1117 entry->dev_addr, entry->size,
1118 ref->size);
1119 }
1120
1121 if (entry->direction == DMA_BIDIRECTIONAL)
1122 goto out;
1123
1124 if (ref->direction != entry->direction) {
1125 err_printk(dev, entry, "device driver syncs "
1126 "DMA memory with different direction "
1127 "[device address=0x%016llx] [size=%llu bytes] "
1128 "[mapped with %s] [synced with %s]\n",
1129 (unsigned long long)ref->dev_addr, entry->size,
1130 dir2name[entry->direction],
1131 dir2name[ref->direction]);
1132 }
1133
1134 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1135 !(ref->direction == DMA_TO_DEVICE))
1136 err_printk(dev, entry, "device driver syncs "
1137 "device read-only DMA memory for cpu "
1138 "[device address=0x%016llx] [size=%llu bytes] "
1139 "[mapped with %s] [synced with %s]\n",
1140 (unsigned long long)ref->dev_addr, entry->size,
1141 dir2name[entry->direction],
1142 dir2name[ref->direction]);
1143
1144 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1145 !(ref->direction == DMA_FROM_DEVICE))
1146 err_printk(dev, entry, "device driver syncs "
1147 "device write-only DMA memory to device "
1148 "[device address=0x%016llx] [size=%llu bytes] "
1149 "[mapped with %s] [synced with %s]\n",
1150 (unsigned long long)ref->dev_addr, entry->size,
1151 dir2name[entry->direction],
1152 dir2name[ref->direction]);
1153
1154 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1155 ref->sg_call_ents != entry->sg_call_ents) {
1156 err_printk(ref->dev, entry, "device driver syncs "
1157 "DMA sg list with different entry count "
1158 "[map count=%d] [sync count=%d]\n",
1159 entry->sg_call_ents, ref->sg_call_ents);
1160 }
1161
1162out:
1163 put_hash_bucket(bucket, flags);
1164}
1165
1166static void check_sg_segment(struct device *dev, struct scatterlist *sg)
1167{
1168#ifdef CONFIG_DMA_API_DEBUG_SG
1169 unsigned int max_seg = dma_get_max_seg_size(dev);
1170 u64 start, end, boundary = dma_get_seg_boundary(dev);
1171
1172 /*
1173 * Either the driver forgot to set dma_parms appropriately, or
1174 * whoever generated the list forgot to check them.
1175 */
1176 if (sg->length > max_seg)
1177 err_printk(dev, NULL, "mapping sg segment longer than device claims to support [len=%u] [max=%u]\n",
1178 sg->length, max_seg);
1179 /*
1180 * In some cases this could potentially be the DMA API
1181 * implementation's fault, but it would usually imply that
1182 * the scatterlist was built inappropriately to begin with.
1183 */
1184 start = sg_dma_address(sg);
1185 end = start + sg_dma_len(sg) - 1;
1186 if ((start ^ end) & ~boundary)
1187 err_printk(dev, NULL, "mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n",
1188 start, end, boundary);
1189#endif
1190}
1191
1192void debug_dma_map_single(struct device *dev, const void *addr,
1193 unsigned long len)
1194{
1195 if (unlikely(dma_debug_disabled()))
1196 return;
1197
1198 if (!virt_addr_valid(addr))
1199 err_printk(dev, NULL, "device driver maps memory from invalid area [addr=%p] [len=%lu]\n",
1200 addr, len);
1201
1202 if (is_vmalloc_addr(addr))
1203 err_printk(dev, NULL, "device driver maps memory from vmalloc area [addr=%p] [len=%lu]\n",
1204 addr, len);
1205}
1206EXPORT_SYMBOL(debug_dma_map_single);
1207
1208void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1209 size_t size, int direction, dma_addr_t dma_addr,
1210 unsigned long attrs)
1211{
1212 struct dma_debug_entry *entry;
1213
1214 if (unlikely(dma_debug_disabled()))
1215 return;
1216
1217 if (dma_mapping_error(dev, dma_addr))
1218 return;
1219
1220 entry = dma_entry_alloc();
1221 if (!entry)
1222 return;
1223
1224 entry->dev = dev;
1225 entry->type = dma_debug_single;
1226 entry->pfn = page_to_pfn(page);
1227 entry->offset = offset;
1228 entry->dev_addr = dma_addr;
1229 entry->size = size;
1230 entry->direction = direction;
1231 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1232
1233 check_for_stack(dev, page, offset);
1234
1235 if (!PageHighMem(page)) {
1236 void *addr = page_address(page) + offset;
1237
1238 check_for_illegal_area(dev, addr, size);
1239 }
1240
1241 add_dma_entry(entry, attrs);
1242}
1243
1244void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1245{
1246 struct dma_debug_entry ref;
1247 struct dma_debug_entry *entry;
1248 struct hash_bucket *bucket;
1249 unsigned long flags;
1250
1251 if (unlikely(dma_debug_disabled()))
1252 return;
1253
1254 ref.dev = dev;
1255 ref.dev_addr = dma_addr;
1256 bucket = get_hash_bucket(&ref, &flags);
1257
1258 list_for_each_entry(entry, &bucket->list, list) {
1259 if (!exact_match(&ref, entry))
1260 continue;
1261
1262 /*
1263 * The same physical address can be mapped multiple
1264 * times. Without a hardware IOMMU this results in the
1265 * same device addresses being put into the dma-debug
1266 * hash multiple times too. This can result in false
1267 * positives being reported. Therefore we implement a
1268 * best-fit algorithm here which updates the first entry
1269 * from the hash which fits the reference value and is
1270 * not currently listed as being checked.
1271 */
1272 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1273 entry->map_err_type = MAP_ERR_CHECKED;
1274 break;
1275 }
1276 }
1277
1278 put_hash_bucket(bucket, flags);
1279}
1280EXPORT_SYMBOL(debug_dma_mapping_error);
1281
1282void debug_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
1283 size_t size, int direction)
1284{
1285 struct dma_debug_entry ref = {
1286 .type = dma_debug_single,
1287 .dev = dev,
1288 .dev_addr = dma_addr,
1289 .size = size,
1290 .direction = direction,
1291 };
1292
1293 if (unlikely(dma_debug_disabled()))
1294 return;
1295 check_unmap(&ref);
1296}
1297
1298void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1299 int nents, int mapped_ents, int direction,
1300 unsigned long attrs)
1301{
1302 struct dma_debug_entry *entry;
1303 struct scatterlist *s;
1304 int i;
1305
1306 if (unlikely(dma_debug_disabled()))
1307 return;
1308
1309 for_each_sg(sg, s, nents, i) {
1310 check_for_stack(dev, sg_page(s), s->offset);
1311 if (!PageHighMem(sg_page(s)))
1312 check_for_illegal_area(dev, sg_virt(s), s->length);
1313 }
1314
1315 for_each_sg(sg, s, mapped_ents, i) {
1316 entry = dma_entry_alloc();
1317 if (!entry)
1318 return;
1319
1320 entry->type = dma_debug_sg;
1321 entry->dev = dev;
1322 entry->pfn = page_to_pfn(sg_page(s));
1323 entry->offset = s->offset;
1324 entry->size = sg_dma_len(s);
1325 entry->dev_addr = sg_dma_address(s);
1326 entry->direction = direction;
1327 entry->sg_call_ents = nents;
1328 entry->sg_mapped_ents = mapped_ents;
1329
1330 check_sg_segment(dev, s);
1331
1332 add_dma_entry(entry, attrs);
1333 }
1334}
1335
1336static int get_nr_mapped_entries(struct device *dev,
1337 struct dma_debug_entry *ref)
1338{
1339 struct dma_debug_entry *entry;
1340 struct hash_bucket *bucket;
1341 unsigned long flags;
1342 int mapped_ents;
1343
1344 bucket = get_hash_bucket(ref, &flags);
1345 entry = bucket_find_exact(bucket, ref);
1346 mapped_ents = 0;
1347
1348 if (entry)
1349 mapped_ents = entry->sg_mapped_ents;
1350 put_hash_bucket(bucket, flags);
1351
1352 return mapped_ents;
1353}
1354
1355void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1356 int nelems, int dir)
1357{
1358 struct scatterlist *s;
1359 int mapped_ents = 0, i;
1360
1361 if (unlikely(dma_debug_disabled()))
1362 return;
1363
1364 for_each_sg(sglist, s, nelems, i) {
1365
1366 struct dma_debug_entry ref = {
1367 .type = dma_debug_sg,
1368 .dev = dev,
1369 .pfn = page_to_pfn(sg_page(s)),
1370 .offset = s->offset,
1371 .dev_addr = sg_dma_address(s),
1372 .size = sg_dma_len(s),
1373 .direction = dir,
1374 .sg_call_ents = nelems,
1375 };
1376
1377 if (mapped_ents && i >= mapped_ents)
1378 break;
1379
1380 if (!i)
1381 mapped_ents = get_nr_mapped_entries(dev, &ref);
1382
1383 check_unmap(&ref);
1384 }
1385}
1386
1387void debug_dma_alloc_coherent(struct device *dev, size_t size,
1388 dma_addr_t dma_addr, void *virt,
1389 unsigned long attrs)
1390{
1391 struct dma_debug_entry *entry;
1392
1393 if (unlikely(dma_debug_disabled()))
1394 return;
1395
1396 if (unlikely(virt == NULL))
1397 return;
1398
1399 /* handle vmalloc and linear addresses */
1400 if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
1401 return;
1402
1403 entry = dma_entry_alloc();
1404 if (!entry)
1405 return;
1406
1407 entry->type = dma_debug_coherent;
1408 entry->dev = dev;
1409 entry->offset = offset_in_page(virt);
1410 entry->size = size;
1411 entry->dev_addr = dma_addr;
1412 entry->direction = DMA_BIDIRECTIONAL;
1413
1414 if (is_vmalloc_addr(virt))
1415 entry->pfn = vmalloc_to_pfn(virt);
1416 else
1417 entry->pfn = page_to_pfn(virt_to_page(virt));
1418
1419 add_dma_entry(entry, attrs);
1420}
1421
1422void debug_dma_free_coherent(struct device *dev, size_t size,
1423 void *virt, dma_addr_t dma_addr)
1424{
1425 struct dma_debug_entry ref = {
1426 .type = dma_debug_coherent,
1427 .dev = dev,
1428 .offset = offset_in_page(virt),
1429 .dev_addr = dma_addr,
1430 .size = size,
1431 .direction = DMA_BIDIRECTIONAL,
1432 };
1433
1434 /* handle vmalloc and linear addresses */
1435 if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
1436 return;
1437
1438 if (is_vmalloc_addr(virt))
1439 ref.pfn = vmalloc_to_pfn(virt);
1440 else
1441 ref.pfn = page_to_pfn(virt_to_page(virt));
1442
1443 if (unlikely(dma_debug_disabled()))
1444 return;
1445
1446 check_unmap(&ref);
1447}
1448
1449void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
1450 int direction, dma_addr_t dma_addr,
1451 unsigned long attrs)
1452{
1453 struct dma_debug_entry *entry;
1454
1455 if (unlikely(dma_debug_disabled()))
1456 return;
1457
1458 entry = dma_entry_alloc();
1459 if (!entry)
1460 return;
1461
1462 entry->type = dma_debug_resource;
1463 entry->dev = dev;
1464 entry->pfn = PHYS_PFN(addr);
1465 entry->offset = offset_in_page(addr);
1466 entry->size = size;
1467 entry->dev_addr = dma_addr;
1468 entry->direction = direction;
1469 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1470
1471 add_dma_entry(entry, attrs);
1472}
1473
1474void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
1475 size_t size, int direction)
1476{
1477 struct dma_debug_entry ref = {
1478 .type = dma_debug_resource,
1479 .dev = dev,
1480 .dev_addr = dma_addr,
1481 .size = size,
1482 .direction = direction,
1483 };
1484
1485 if (unlikely(dma_debug_disabled()))
1486 return;
1487
1488 check_unmap(&ref);
1489}
1490
1491void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1492 size_t size, 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, true);
1507}
1508
1509void debug_dma_sync_single_for_device(struct device *dev,
1510 dma_addr_t dma_handle, size_t size,
1511 int direction)
1512{
1513 struct dma_debug_entry ref;
1514
1515 if (unlikely(dma_debug_disabled()))
1516 return;
1517
1518 ref.type = dma_debug_single;
1519 ref.dev = dev;
1520 ref.dev_addr = dma_handle;
1521 ref.size = size;
1522 ref.direction = direction;
1523 ref.sg_call_ents = 0;
1524
1525 check_sync(dev, &ref, false);
1526}
1527
1528void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1529 int nelems, int direction)
1530{
1531 struct scatterlist *s;
1532 int mapped_ents = 0, i;
1533
1534 if (unlikely(dma_debug_disabled()))
1535 return;
1536
1537 for_each_sg(sg, s, nelems, i) {
1538
1539 struct dma_debug_entry ref = {
1540 .type = dma_debug_sg,
1541 .dev = dev,
1542 .pfn = page_to_pfn(sg_page(s)),
1543 .offset = s->offset,
1544 .dev_addr = sg_dma_address(s),
1545 .size = sg_dma_len(s),
1546 .direction = direction,
1547 .sg_call_ents = nelems,
1548 };
1549
1550 if (!i)
1551 mapped_ents = get_nr_mapped_entries(dev, &ref);
1552
1553 if (i >= mapped_ents)
1554 break;
1555
1556 check_sync(dev, &ref, true);
1557 }
1558}
1559
1560void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1561 int nelems, int direction)
1562{
1563 struct scatterlist *s;
1564 int mapped_ents = 0, i;
1565
1566 if (unlikely(dma_debug_disabled()))
1567 return;
1568
1569 for_each_sg(sg, s, nelems, i) {
1570
1571 struct dma_debug_entry ref = {
1572 .type = dma_debug_sg,
1573 .dev = dev,
1574 .pfn = page_to_pfn(sg_page(s)),
1575 .offset = s->offset,
1576 .dev_addr = sg_dma_address(s),
1577 .size = sg_dma_len(s),
1578 .direction = direction,
1579 .sg_call_ents = nelems,
1580 };
1581 if (!i)
1582 mapped_ents = get_nr_mapped_entries(dev, &ref);
1583
1584 if (i >= mapped_ents)
1585 break;
1586
1587 check_sync(dev, &ref, false);
1588 }
1589}
1590
1591static int __init dma_debug_driver_setup(char *str)
1592{
1593 int i;
1594
1595 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1596 current_driver_name[i] = *str;
1597 if (*str == 0)
1598 break;
1599 }
1600
1601 if (current_driver_name[0])
1602 pr_info("enable driver filter for driver [%s]\n",
1603 current_driver_name);
1604
1605
1606 return 1;
1607}
1608__setup("dma_debug_driver=", dma_debug_driver_setup);