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-rw-r--r--lib/dma-debug.c1246
1 files changed, 1246 insertions, 0 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
new file mode 100644
index 000000000000..ad65fc0317d9
--- /dev/null
+++ b/lib/dma-debug.c
@@ -0,0 +1,1246 @@
1/*
2 * Copyright (C) 2008 Advanced Micro Devices, Inc.
3 *
4 * Author: Joerg Roedel <joerg.roedel@amd.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/scatterlist.h>
21#include <linux/dma-mapping.h>
22#include <linux/stacktrace.h>
23#include <linux/dma-debug.h>
24#include <linux/spinlock.h>
25#include <linux/debugfs.h>
26#include <linux/uaccess.h>
27#include <linux/device.h>
28#include <linux/types.h>
29#include <linux/sched.h>
30#include <linux/ctype.h>
31#include <linux/list.h>
32#include <linux/slab.h>
33
34#include <asm/sections.h>
35
36#define HASH_SIZE 1024ULL
37#define HASH_FN_SHIFT 13
38#define HASH_FN_MASK (HASH_SIZE - 1)
39
40enum {
41 dma_debug_single,
42 dma_debug_page,
43 dma_debug_sg,
44 dma_debug_coherent,
45};
46
47#define DMA_DEBUG_STACKTRACE_ENTRIES 5
48
49struct dma_debug_entry {
50 struct list_head list;
51 struct device *dev;
52 int type;
53 phys_addr_t paddr;
54 u64 dev_addr;
55 u64 size;
56 int direction;
57 int sg_call_ents;
58 int sg_mapped_ents;
59#ifdef CONFIG_STACKTRACE
60 struct stack_trace stacktrace;
61 unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
62#endif
63};
64
65struct hash_bucket {
66 struct list_head list;
67 spinlock_t lock;
68} ____cacheline_aligned_in_smp;
69
70/* Hash list to save the allocated dma addresses */
71static struct hash_bucket dma_entry_hash[HASH_SIZE];
72/* List of pre-allocated dma_debug_entry's */
73static LIST_HEAD(free_entries);
74/* Lock for the list above */
75static DEFINE_SPINLOCK(free_entries_lock);
76
77/* Global disable flag - will be set in case of an error */
78static bool global_disable __read_mostly;
79
80/* Global error count */
81static u32 error_count;
82
83/* Global error show enable*/
84static u32 show_all_errors __read_mostly;
85/* Number of errors to show */
86static u32 show_num_errors = 1;
87
88static u32 num_free_entries;
89static u32 min_free_entries;
90static u32 nr_total_entries;
91
92/* number of preallocated entries requested by kernel cmdline */
93static u32 req_entries;
94
95/* debugfs dentry's for the stuff above */
96static struct dentry *dma_debug_dent __read_mostly;
97static struct dentry *global_disable_dent __read_mostly;
98static struct dentry *error_count_dent __read_mostly;
99static struct dentry *show_all_errors_dent __read_mostly;
100static struct dentry *show_num_errors_dent __read_mostly;
101static struct dentry *num_free_entries_dent __read_mostly;
102static struct dentry *min_free_entries_dent __read_mostly;
103static struct dentry *filter_dent __read_mostly;
104
105/* per-driver filter related state */
106
107#define NAME_MAX_LEN 64
108
109static char current_driver_name[NAME_MAX_LEN] __read_mostly;
110static struct device_driver *current_driver __read_mostly;
111
112static DEFINE_RWLOCK(driver_name_lock);
113
114static const char *type2name[4] = { "single", "page",
115 "scather-gather", "coherent" };
116
117static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
118 "DMA_FROM_DEVICE", "DMA_NONE" };
119
120/* little merge helper - remove it after the merge window */
121#ifndef BUS_NOTIFY_UNBOUND_DRIVER
122#define BUS_NOTIFY_UNBOUND_DRIVER 0x0005
123#endif
124
125/*
126 * The access to some variables in this macro is racy. We can't use atomic_t
127 * here because all these variables are exported to debugfs. Some of them even
128 * writeable. This is also the reason why a lock won't help much. But anyway,
129 * the races are no big deal. Here is why:
130 *
131 * error_count: the addition is racy, but the worst thing that can happen is
132 * that we don't count some errors
133 * show_num_errors: the subtraction is racy. Also no big deal because in
134 * worst case this will result in one warning more in the
135 * system log than the user configured. This variable is
136 * writeable via debugfs.
137 */
138static inline void dump_entry_trace(struct dma_debug_entry *entry)
139{
140#ifdef CONFIG_STACKTRACE
141 if (entry) {
142 pr_warning("Mapped at:\n");
143 print_stack_trace(&entry->stacktrace, 0);
144 }
145#endif
146}
147
148static bool driver_filter(struct device *dev)
149{
150 struct device_driver *drv;
151 unsigned long flags;
152 bool ret;
153
154 /* driver filter off */
155 if (likely(!current_driver_name[0]))
156 return true;
157
158 /* driver filter on and initialized */
159 if (current_driver && dev->driver == current_driver)
160 return true;
161
162 if (current_driver || !current_driver_name[0])
163 return false;
164
165 /* driver filter on but not yet initialized */
166 drv = get_driver(dev->driver);
167 if (!drv)
168 return false;
169
170 /* lock to protect against change of current_driver_name */
171 read_lock_irqsave(&driver_name_lock, flags);
172
173 ret = false;
174 if (drv->name &&
175 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
176 current_driver = drv;
177 ret = true;
178 }
179
180 read_unlock_irqrestore(&driver_name_lock, flags);
181 put_driver(drv);
182
183 return ret;
184}
185
186#define err_printk(dev, entry, format, arg...) do { \
187 error_count += 1; \
188 if (driver_filter(dev) && \
189 (show_all_errors || show_num_errors > 0)) { \
190 WARN(1, "%s %s: " format, \
191 dev_driver_string(dev), \
192 dev_name(dev) , ## arg); \
193 dump_entry_trace(entry); \
194 } \
195 if (!show_all_errors && show_num_errors > 0) \
196 show_num_errors -= 1; \
197 } while (0);
198
199/*
200 * Hash related functions
201 *
202 * Every DMA-API request is saved into a struct dma_debug_entry. To
203 * have quick access to these structs they are stored into a hash.
204 */
205static int hash_fn(struct dma_debug_entry *entry)
206{
207 /*
208 * Hash function is based on the dma address.
209 * We use bits 20-27 here as the index into the hash
210 */
211 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
212}
213
214/*
215 * Request exclusive access to a hash bucket for a given dma_debug_entry.
216 */
217static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
218 unsigned long *flags)
219{
220 int idx = hash_fn(entry);
221 unsigned long __flags;
222
223 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
224 *flags = __flags;
225 return &dma_entry_hash[idx];
226}
227
228/*
229 * Give up exclusive access to the hash bucket
230 */
231static void put_hash_bucket(struct hash_bucket *bucket,
232 unsigned long *flags)
233{
234 unsigned long __flags = *flags;
235
236 spin_unlock_irqrestore(&bucket->lock, __flags);
237}
238
239/*
240 * Search a given entry in the hash bucket list
241 */
242static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
243 struct dma_debug_entry *ref)
244{
245 struct dma_debug_entry *entry, *ret = NULL;
246 int matches = 0, match_lvl, last_lvl = 0;
247
248 list_for_each_entry(entry, &bucket->list, list) {
249 if ((entry->dev_addr != ref->dev_addr) ||
250 (entry->dev != ref->dev))
251 continue;
252
253 /*
254 * Some drivers map the same physical address multiple
255 * times. Without a hardware IOMMU this results in the
256 * same device addresses being put into the dma-debug
257 * hash multiple times too. This can result in false
258 * positives being reported. Therfore we implement a
259 * best-fit algorithm here which returns the entry from
260 * the hash which fits best to the reference value
261 * instead of the first-fit.
262 */
263 matches += 1;
264 match_lvl = 0;
265 entry->size == ref->size ? ++match_lvl : match_lvl;
266 entry->type == ref->type ? ++match_lvl : match_lvl;
267 entry->direction == ref->direction ? ++match_lvl : match_lvl;
268
269 if (match_lvl == 3) {
270 /* perfect-fit - return the result */
271 return entry;
272 } else if (match_lvl > last_lvl) {
273 /*
274 * We found an entry that fits better then the
275 * previous one
276 */
277 last_lvl = match_lvl;
278 ret = entry;
279 }
280 }
281
282 /*
283 * If we have multiple matches but no perfect-fit, just return
284 * NULL.
285 */
286 ret = (matches == 1) ? ret : NULL;
287
288 return ret;
289}
290
291/*
292 * Add an entry to a hash bucket
293 */
294static void hash_bucket_add(struct hash_bucket *bucket,
295 struct dma_debug_entry *entry)
296{
297 list_add_tail(&entry->list, &bucket->list);
298}
299
300/*
301 * Remove entry from a hash bucket list
302 */
303static void hash_bucket_del(struct dma_debug_entry *entry)
304{
305 list_del(&entry->list);
306}
307
308/*
309 * Dump mapping entries for debugging purposes
310 */
311void debug_dma_dump_mappings(struct device *dev)
312{
313 int idx;
314
315 for (idx = 0; idx < HASH_SIZE; idx++) {
316 struct hash_bucket *bucket = &dma_entry_hash[idx];
317 struct dma_debug_entry *entry;
318 unsigned long flags;
319
320 spin_lock_irqsave(&bucket->lock, flags);
321
322 list_for_each_entry(entry, &bucket->list, list) {
323 if (!dev || dev == entry->dev) {
324 dev_info(entry->dev,
325 "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
326 type2name[entry->type], idx,
327 (unsigned long long)entry->paddr,
328 entry->dev_addr, entry->size,
329 dir2name[entry->direction]);
330 }
331 }
332
333 spin_unlock_irqrestore(&bucket->lock, flags);
334 }
335}
336EXPORT_SYMBOL(debug_dma_dump_mappings);
337
338/*
339 * Wrapper function for adding an entry to the hash.
340 * This function takes care of locking itself.
341 */
342static void add_dma_entry(struct dma_debug_entry *entry)
343{
344 struct hash_bucket *bucket;
345 unsigned long flags;
346
347 bucket = get_hash_bucket(entry, &flags);
348 hash_bucket_add(bucket, entry);
349 put_hash_bucket(bucket, &flags);
350}
351
352static struct dma_debug_entry *__dma_entry_alloc(void)
353{
354 struct dma_debug_entry *entry;
355
356 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
357 list_del(&entry->list);
358 memset(entry, 0, sizeof(*entry));
359
360 num_free_entries -= 1;
361 if (num_free_entries < min_free_entries)
362 min_free_entries = num_free_entries;
363
364 return entry;
365}
366
367/* struct dma_entry allocator
368 *
369 * The next two functions implement the allocator for
370 * struct dma_debug_entries.
371 */
372static struct dma_debug_entry *dma_entry_alloc(void)
373{
374 struct dma_debug_entry *entry = NULL;
375 unsigned long flags;
376
377 spin_lock_irqsave(&free_entries_lock, flags);
378
379 if (list_empty(&free_entries)) {
380 pr_err("DMA-API: debugging out of memory - disabling\n");
381 global_disable = true;
382 goto out;
383 }
384
385 entry = __dma_entry_alloc();
386
387#ifdef CONFIG_STACKTRACE
388 entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
389 entry->stacktrace.entries = entry->st_entries;
390 entry->stacktrace.skip = 2;
391 save_stack_trace(&entry->stacktrace);
392#endif
393
394out:
395 spin_unlock_irqrestore(&free_entries_lock, flags);
396
397 return entry;
398}
399
400static void dma_entry_free(struct dma_debug_entry *entry)
401{
402 unsigned long flags;
403
404 /*
405 * add to beginning of the list - this way the entries are
406 * more likely cache hot when they are reallocated.
407 */
408 spin_lock_irqsave(&free_entries_lock, flags);
409 list_add(&entry->list, &free_entries);
410 num_free_entries += 1;
411 spin_unlock_irqrestore(&free_entries_lock, flags);
412}
413
414int dma_debug_resize_entries(u32 num_entries)
415{
416 int i, delta, ret = 0;
417 unsigned long flags;
418 struct dma_debug_entry *entry;
419 LIST_HEAD(tmp);
420
421 spin_lock_irqsave(&free_entries_lock, flags);
422
423 if (nr_total_entries < num_entries) {
424 delta = num_entries - nr_total_entries;
425
426 spin_unlock_irqrestore(&free_entries_lock, flags);
427
428 for (i = 0; i < delta; i++) {
429 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
430 if (!entry)
431 break;
432
433 list_add_tail(&entry->list, &tmp);
434 }
435
436 spin_lock_irqsave(&free_entries_lock, flags);
437
438 list_splice(&tmp, &free_entries);
439 nr_total_entries += i;
440 num_free_entries += i;
441 } else {
442 delta = nr_total_entries - num_entries;
443
444 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
445 entry = __dma_entry_alloc();
446 kfree(entry);
447 }
448
449 nr_total_entries -= i;
450 }
451
452 if (nr_total_entries != num_entries)
453 ret = 1;
454
455 spin_unlock_irqrestore(&free_entries_lock, flags);
456
457 return ret;
458}
459EXPORT_SYMBOL(dma_debug_resize_entries);
460
461/*
462 * DMA-API debugging init code
463 *
464 * The init code does two things:
465 * 1. Initialize core data structures
466 * 2. Preallocate a given number of dma_debug_entry structs
467 */
468
469static int prealloc_memory(u32 num_entries)
470{
471 struct dma_debug_entry *entry, *next_entry;
472 int i;
473
474 for (i = 0; i < num_entries; ++i) {
475 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
476 if (!entry)
477 goto out_err;
478
479 list_add_tail(&entry->list, &free_entries);
480 }
481
482 num_free_entries = num_entries;
483 min_free_entries = num_entries;
484
485 pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
486
487 return 0;
488
489out_err:
490
491 list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
492 list_del(&entry->list);
493 kfree(entry);
494 }
495
496 return -ENOMEM;
497}
498
499static ssize_t filter_read(struct file *file, char __user *user_buf,
500 size_t count, loff_t *ppos)
501{
502 char buf[NAME_MAX_LEN + 1];
503 unsigned long flags;
504 int len;
505
506 if (!current_driver_name[0])
507 return 0;
508
509 /*
510 * We can't copy to userspace directly because current_driver_name can
511 * only be read under the driver_name_lock with irqs disabled. So
512 * create a temporary copy first.
513 */
514 read_lock_irqsave(&driver_name_lock, flags);
515 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
516 read_unlock_irqrestore(&driver_name_lock, flags);
517
518 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
519}
520
521static ssize_t filter_write(struct file *file, const char __user *userbuf,
522 size_t count, loff_t *ppos)
523{
524 char buf[NAME_MAX_LEN];
525 unsigned long flags;
526 size_t len;
527 int i;
528
529 /*
530 * We can't copy from userspace directly. Access to
531 * current_driver_name is protected with a write_lock with irqs
532 * disabled. Since copy_from_user can fault and may sleep we
533 * need to copy to temporary buffer first
534 */
535 len = min(count, (size_t)(NAME_MAX_LEN - 1));
536 if (copy_from_user(buf, userbuf, len))
537 return -EFAULT;
538
539 buf[len] = 0;
540
541 write_lock_irqsave(&driver_name_lock, flags);
542
543 /*
544 * Now handle the string we got from userspace very carefully.
545 * The rules are:
546 * - only use the first token we got
547 * - token delimiter is everything looking like a space
548 * character (' ', '\n', '\t' ...)
549 *
550 */
551 if (!isalnum(buf[0])) {
552 /*
553 * If the first character userspace gave us is not
554 * alphanumerical then assume the filter should be
555 * switched off.
556 */
557 if (current_driver_name[0])
558 pr_info("DMA-API: switching off dma-debug driver filter\n");
559 current_driver_name[0] = 0;
560 current_driver = NULL;
561 goto out_unlock;
562 }
563
564 /*
565 * Now parse out the first token and use it as the name for the
566 * driver to filter for.
567 */
568 for (i = 0; i < NAME_MAX_LEN; ++i) {
569 current_driver_name[i] = buf[i];
570 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
571 break;
572 }
573 current_driver_name[i] = 0;
574 current_driver = NULL;
575
576 pr_info("DMA-API: enable driver filter for driver [%s]\n",
577 current_driver_name);
578
579out_unlock:
580 write_unlock_irqrestore(&driver_name_lock, flags);
581
582 return count;
583}
584
585const struct file_operations filter_fops = {
586 .read = filter_read,
587 .write = filter_write,
588};
589
590static int dma_debug_fs_init(void)
591{
592 dma_debug_dent = debugfs_create_dir("dma-api", NULL);
593 if (!dma_debug_dent) {
594 pr_err("DMA-API: can not create debugfs directory\n");
595 return -ENOMEM;
596 }
597
598 global_disable_dent = debugfs_create_bool("disabled", 0444,
599 dma_debug_dent,
600 (u32 *)&global_disable);
601 if (!global_disable_dent)
602 goto out_err;
603
604 error_count_dent = debugfs_create_u32("error_count", 0444,
605 dma_debug_dent, &error_count);
606 if (!error_count_dent)
607 goto out_err;
608
609 show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
610 dma_debug_dent,
611 &show_all_errors);
612 if (!show_all_errors_dent)
613 goto out_err;
614
615 show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
616 dma_debug_dent,
617 &show_num_errors);
618 if (!show_num_errors_dent)
619 goto out_err;
620
621 num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
622 dma_debug_dent,
623 &num_free_entries);
624 if (!num_free_entries_dent)
625 goto out_err;
626
627 min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
628 dma_debug_dent,
629 &min_free_entries);
630 if (!min_free_entries_dent)
631 goto out_err;
632
633 filter_dent = debugfs_create_file("driver_filter", 0644,
634 dma_debug_dent, NULL, &filter_fops);
635 if (!filter_dent)
636 goto out_err;
637
638 return 0;
639
640out_err:
641 debugfs_remove_recursive(dma_debug_dent);
642
643 return -ENOMEM;
644}
645
646static int device_dma_allocations(struct device *dev)
647{
648 struct dma_debug_entry *entry;
649 unsigned long flags;
650 int count = 0, i;
651
652 local_irq_save(flags);
653
654 for (i = 0; i < HASH_SIZE; ++i) {
655 spin_lock(&dma_entry_hash[i].lock);
656 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
657 if (entry->dev == dev)
658 count += 1;
659 }
660 spin_unlock(&dma_entry_hash[i].lock);
661 }
662
663 local_irq_restore(flags);
664
665 return count;
666}
667
668static int dma_debug_device_change(struct notifier_block *nb,
669 unsigned long action, void *data)
670{
671 struct device *dev = data;
672 int count;
673
674
675 switch (action) {
676 case BUS_NOTIFY_UNBOUND_DRIVER:
677 count = device_dma_allocations(dev);
678 if (count == 0)
679 break;
680 err_printk(dev, NULL, "DMA-API: device driver has pending "
681 "DMA allocations while released from device "
682 "[count=%d]\n", count);
683 break;
684 default:
685 break;
686 }
687
688 return 0;
689}
690
691void dma_debug_add_bus(struct bus_type *bus)
692{
693 struct notifier_block *nb;
694
695 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
696 if (nb == NULL) {
697 pr_err("dma_debug_add_bus: out of memory\n");
698 return;
699 }
700
701 nb->notifier_call = dma_debug_device_change;
702
703 bus_register_notifier(bus, nb);
704}
705
706/*
707 * Let the architectures decide how many entries should be preallocated.
708 */
709void dma_debug_init(u32 num_entries)
710{
711 int i;
712
713 if (global_disable)
714 return;
715
716 for (i = 0; i < HASH_SIZE; ++i) {
717 INIT_LIST_HEAD(&dma_entry_hash[i].list);
718 dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
719 }
720
721 if (dma_debug_fs_init() != 0) {
722 pr_err("DMA-API: error creating debugfs entries - disabling\n");
723 global_disable = true;
724
725 return;
726 }
727
728 if (req_entries)
729 num_entries = req_entries;
730
731 if (prealloc_memory(num_entries) != 0) {
732 pr_err("DMA-API: debugging out of memory error - disabled\n");
733 global_disable = true;
734
735 return;
736 }
737
738 nr_total_entries = num_free_entries;
739
740 pr_info("DMA-API: debugging enabled by kernel config\n");
741}
742
743static __init int dma_debug_cmdline(char *str)
744{
745 if (!str)
746 return -EINVAL;
747
748 if (strncmp(str, "off", 3) == 0) {
749 pr_info("DMA-API: debugging disabled on kernel command line\n");
750 global_disable = true;
751 }
752
753 return 0;
754}
755
756static __init int dma_debug_entries_cmdline(char *str)
757{
758 int res;
759
760 if (!str)
761 return -EINVAL;
762
763 res = get_option(&str, &req_entries);
764
765 if (!res)
766 req_entries = 0;
767
768 return 0;
769}
770
771__setup("dma_debug=", dma_debug_cmdline);
772__setup("dma_debug_entries=", dma_debug_entries_cmdline);
773
774static void check_unmap(struct dma_debug_entry *ref)
775{
776 struct dma_debug_entry *entry;
777 struct hash_bucket *bucket;
778 unsigned long flags;
779
780 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
781 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
782 "to free an invalid DMA memory address\n");
783 return;
784 }
785
786 bucket = get_hash_bucket(ref, &flags);
787 entry = hash_bucket_find(bucket, ref);
788
789 if (!entry) {
790 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
791 "to free DMA memory it has not allocated "
792 "[device address=0x%016llx] [size=%llu bytes]\n",
793 ref->dev_addr, ref->size);
794 goto out;
795 }
796
797 if (ref->size != entry->size) {
798 err_printk(ref->dev, entry, "DMA-API: device driver frees "
799 "DMA memory with different size "
800 "[device address=0x%016llx] [map size=%llu bytes] "
801 "[unmap size=%llu bytes]\n",
802 ref->dev_addr, entry->size, ref->size);
803 }
804
805 if (ref->type != entry->type) {
806 err_printk(ref->dev, entry, "DMA-API: device driver frees "
807 "DMA memory with wrong function "
808 "[device address=0x%016llx] [size=%llu bytes] "
809 "[mapped as %s] [unmapped as %s]\n",
810 ref->dev_addr, ref->size,
811 type2name[entry->type], type2name[ref->type]);
812 } else if ((entry->type == dma_debug_coherent) &&
813 (ref->paddr != entry->paddr)) {
814 err_printk(ref->dev, entry, "DMA-API: device driver frees "
815 "DMA memory with different CPU address "
816 "[device address=0x%016llx] [size=%llu bytes] "
817 "[cpu alloc address=%p] [cpu free address=%p]",
818 ref->dev_addr, ref->size,
819 (void *)entry->paddr, (void *)ref->paddr);
820 }
821
822 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
823 ref->sg_call_ents != entry->sg_call_ents) {
824 err_printk(ref->dev, entry, "DMA-API: device driver frees "
825 "DMA sg list with different entry count "
826 "[map count=%d] [unmap count=%d]\n",
827 entry->sg_call_ents, ref->sg_call_ents);
828 }
829
830 /*
831 * This may be no bug in reality - but most implementations of the
832 * DMA API don't handle this properly, so check for it here
833 */
834 if (ref->direction != entry->direction) {
835 err_printk(ref->dev, entry, "DMA-API: device driver frees "
836 "DMA memory with different direction "
837 "[device address=0x%016llx] [size=%llu bytes] "
838 "[mapped with %s] [unmapped with %s]\n",
839 ref->dev_addr, ref->size,
840 dir2name[entry->direction],
841 dir2name[ref->direction]);
842 }
843
844 hash_bucket_del(entry);
845 dma_entry_free(entry);
846
847out:
848 put_hash_bucket(bucket, &flags);
849}
850
851static void check_for_stack(struct device *dev, void *addr)
852{
853 if (object_is_on_stack(addr))
854 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
855 "stack [addr=%p]\n", addr);
856}
857
858static inline bool overlap(void *addr, u64 size, void *start, void *end)
859{
860 void *addr2 = (char *)addr + size;
861
862 return ((addr >= start && addr < end) ||
863 (addr2 >= start && addr2 < end) ||
864 ((addr < start) && (addr2 >= end)));
865}
866
867static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
868{
869 if (overlap(addr, size, _text, _etext) ||
870 overlap(addr, size, __start_rodata, __end_rodata))
871 err_printk(dev, NULL, "DMA-API: device driver maps "
872 "memory from kernel text or rodata "
873 "[addr=%p] [size=%llu]\n", addr, size);
874}
875
876static void check_sync(struct device *dev, dma_addr_t addr,
877 u64 size, u64 offset, int direction, bool to_cpu)
878{
879 struct dma_debug_entry ref = {
880 .dev = dev,
881 .dev_addr = addr,
882 .size = size,
883 .direction = direction,
884 };
885 struct dma_debug_entry *entry;
886 struct hash_bucket *bucket;
887 unsigned long flags;
888
889 bucket = get_hash_bucket(&ref, &flags);
890
891 entry = hash_bucket_find(bucket, &ref);
892
893 if (!entry) {
894 err_printk(dev, NULL, "DMA-API: device driver tries "
895 "to sync DMA memory it has not allocated "
896 "[device address=0x%016llx] [size=%llu bytes]\n",
897 (unsigned long long)addr, size);
898 goto out;
899 }
900
901 if ((offset + size) > entry->size) {
902 err_printk(dev, entry, "DMA-API: device driver syncs"
903 " DMA memory outside allocated range "
904 "[device address=0x%016llx] "
905 "[allocation size=%llu bytes] [sync offset=%llu] "
906 "[sync size=%llu]\n", entry->dev_addr, entry->size,
907 offset, size);
908 }
909
910 if (direction != entry->direction) {
911 err_printk(dev, entry, "DMA-API: device driver syncs "
912 "DMA memory with different direction "
913 "[device address=0x%016llx] [size=%llu bytes] "
914 "[mapped with %s] [synced with %s]\n",
915 (unsigned long long)addr, entry->size,
916 dir2name[entry->direction],
917 dir2name[direction]);
918 }
919
920 if (entry->direction == DMA_BIDIRECTIONAL)
921 goto out;
922
923 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
924 !(direction == DMA_TO_DEVICE))
925 err_printk(dev, entry, "DMA-API: device driver syncs "
926 "device read-only DMA memory for cpu "
927 "[device address=0x%016llx] [size=%llu bytes] "
928 "[mapped with %s] [synced with %s]\n",
929 (unsigned long long)addr, entry->size,
930 dir2name[entry->direction],
931 dir2name[direction]);
932
933 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
934 !(direction == DMA_FROM_DEVICE))
935 err_printk(dev, entry, "DMA-API: device driver syncs "
936 "device write-only DMA memory to device "
937 "[device address=0x%016llx] [size=%llu bytes] "
938 "[mapped with %s] [synced with %s]\n",
939 (unsigned long long)addr, entry->size,
940 dir2name[entry->direction],
941 dir2name[direction]);
942
943out:
944 put_hash_bucket(bucket, &flags);
945
946}
947
948void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
949 size_t size, int direction, dma_addr_t dma_addr,
950 bool map_single)
951{
952 struct dma_debug_entry *entry;
953
954 if (unlikely(global_disable))
955 return;
956
957 if (unlikely(dma_mapping_error(dev, dma_addr)))
958 return;
959
960 entry = dma_entry_alloc();
961 if (!entry)
962 return;
963
964 entry->dev = dev;
965 entry->type = dma_debug_page;
966 entry->paddr = page_to_phys(page) + offset;
967 entry->dev_addr = dma_addr;
968 entry->size = size;
969 entry->direction = direction;
970
971 if (map_single)
972 entry->type = dma_debug_single;
973
974 if (!PageHighMem(page)) {
975 void *addr = ((char *)page_address(page)) + offset;
976 check_for_stack(dev, addr);
977 check_for_illegal_area(dev, addr, size);
978 }
979
980 add_dma_entry(entry);
981}
982EXPORT_SYMBOL(debug_dma_map_page);
983
984void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
985 size_t size, int direction, bool map_single)
986{
987 struct dma_debug_entry ref = {
988 .type = dma_debug_page,
989 .dev = dev,
990 .dev_addr = addr,
991 .size = size,
992 .direction = direction,
993 };
994
995 if (unlikely(global_disable))
996 return;
997
998 if (map_single)
999 ref.type = dma_debug_single;
1000
1001 check_unmap(&ref);
1002}
1003EXPORT_SYMBOL(debug_dma_unmap_page);
1004
1005void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1006 int nents, int mapped_ents, int direction)
1007{
1008 struct dma_debug_entry *entry;
1009 struct scatterlist *s;
1010 int i;
1011
1012 if (unlikely(global_disable))
1013 return;
1014
1015 for_each_sg(sg, s, mapped_ents, i) {
1016 entry = dma_entry_alloc();
1017 if (!entry)
1018 return;
1019
1020 entry->type = dma_debug_sg;
1021 entry->dev = dev;
1022 entry->paddr = sg_phys(s);
1023 entry->size = sg_dma_len(s);
1024 entry->dev_addr = sg_dma_address(s);
1025 entry->direction = direction;
1026 entry->sg_call_ents = nents;
1027 entry->sg_mapped_ents = mapped_ents;
1028
1029 if (!PageHighMem(sg_page(s))) {
1030 check_for_stack(dev, sg_virt(s));
1031 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1032 }
1033
1034 add_dma_entry(entry);
1035 }
1036}
1037EXPORT_SYMBOL(debug_dma_map_sg);
1038
1039static int get_nr_mapped_entries(struct device *dev, struct scatterlist *s)
1040{
1041 struct dma_debug_entry *entry, ref;
1042 struct hash_bucket *bucket;
1043 unsigned long flags;
1044 int mapped_ents;
1045
1046 ref.dev = dev;
1047 ref.dev_addr = sg_dma_address(s);
1048 ref.size = sg_dma_len(s),
1049
1050 bucket = get_hash_bucket(&ref, &flags);
1051 entry = hash_bucket_find(bucket, &ref);
1052 mapped_ents = 0;
1053
1054 if (entry)
1055 mapped_ents = entry->sg_mapped_ents;
1056 put_hash_bucket(bucket, &flags);
1057
1058 return mapped_ents;
1059}
1060
1061void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1062 int nelems, int dir)
1063{
1064 struct scatterlist *s;
1065 int mapped_ents = 0, i;
1066
1067 if (unlikely(global_disable))
1068 return;
1069
1070 for_each_sg(sglist, s, nelems, i) {
1071
1072 struct dma_debug_entry ref = {
1073 .type = dma_debug_sg,
1074 .dev = dev,
1075 .paddr = sg_phys(s),
1076 .dev_addr = sg_dma_address(s),
1077 .size = sg_dma_len(s),
1078 .direction = dir,
1079 .sg_call_ents = 0,
1080 };
1081
1082 if (mapped_ents && i >= mapped_ents)
1083 break;
1084
1085 if (!i) {
1086 ref.sg_call_ents = nelems;
1087 mapped_ents = get_nr_mapped_entries(dev, s);
1088 }
1089
1090 check_unmap(&ref);
1091 }
1092}
1093EXPORT_SYMBOL(debug_dma_unmap_sg);
1094
1095void debug_dma_alloc_coherent(struct device *dev, size_t size,
1096 dma_addr_t dma_addr, void *virt)
1097{
1098 struct dma_debug_entry *entry;
1099
1100 if (unlikely(global_disable))
1101 return;
1102
1103 if (unlikely(virt == NULL))
1104 return;
1105
1106 entry = dma_entry_alloc();
1107 if (!entry)
1108 return;
1109
1110 entry->type = dma_debug_coherent;
1111 entry->dev = dev;
1112 entry->paddr = virt_to_phys(virt);
1113 entry->size = size;
1114 entry->dev_addr = dma_addr;
1115 entry->direction = DMA_BIDIRECTIONAL;
1116
1117 add_dma_entry(entry);
1118}
1119EXPORT_SYMBOL(debug_dma_alloc_coherent);
1120
1121void debug_dma_free_coherent(struct device *dev, size_t size,
1122 void *virt, dma_addr_t addr)
1123{
1124 struct dma_debug_entry ref = {
1125 .type = dma_debug_coherent,
1126 .dev = dev,
1127 .paddr = virt_to_phys(virt),
1128 .dev_addr = addr,
1129 .size = size,
1130 .direction = DMA_BIDIRECTIONAL,
1131 };
1132
1133 if (unlikely(global_disable))
1134 return;
1135
1136 check_unmap(&ref);
1137}
1138EXPORT_SYMBOL(debug_dma_free_coherent);
1139
1140void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1141 size_t size, int direction)
1142{
1143 if (unlikely(global_disable))
1144 return;
1145
1146 check_sync(dev, dma_handle, size, 0, direction, true);
1147}
1148EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1149
1150void debug_dma_sync_single_for_device(struct device *dev,
1151 dma_addr_t dma_handle, size_t size,
1152 int direction)
1153{
1154 if (unlikely(global_disable))
1155 return;
1156
1157 check_sync(dev, dma_handle, size, 0, direction, false);
1158}
1159EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1160
1161void debug_dma_sync_single_range_for_cpu(struct device *dev,
1162 dma_addr_t dma_handle,
1163 unsigned long offset, size_t size,
1164 int direction)
1165{
1166 if (unlikely(global_disable))
1167 return;
1168
1169 check_sync(dev, dma_handle, size, offset, direction, true);
1170}
1171EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1172
1173void debug_dma_sync_single_range_for_device(struct device *dev,
1174 dma_addr_t dma_handle,
1175 unsigned long offset,
1176 size_t size, int direction)
1177{
1178 if (unlikely(global_disable))
1179 return;
1180
1181 check_sync(dev, dma_handle, size, offset, direction, false);
1182}
1183EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1184
1185void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1186 int nelems, int direction)
1187{
1188 struct scatterlist *s;
1189 int mapped_ents = 0, i;
1190
1191 if (unlikely(global_disable))
1192 return;
1193
1194 for_each_sg(sg, s, nelems, i) {
1195 if (!i)
1196 mapped_ents = get_nr_mapped_entries(dev, s);
1197
1198 if (i >= mapped_ents)
1199 break;
1200
1201 check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0,
1202 direction, true);
1203 }
1204}
1205EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1206
1207void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1208 int nelems, int direction)
1209{
1210 struct scatterlist *s;
1211 int mapped_ents = 0, i;
1212
1213 if (unlikely(global_disable))
1214 return;
1215
1216 for_each_sg(sg, s, nelems, i) {
1217 if (!i)
1218 mapped_ents = get_nr_mapped_entries(dev, s);
1219
1220 if (i >= mapped_ents)
1221 break;
1222
1223 check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0,
1224 direction, false);
1225 }
1226}
1227EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1228
1229static int __init dma_debug_driver_setup(char *str)
1230{
1231 int i;
1232
1233 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1234 current_driver_name[i] = *str;
1235 if (*str == 0)
1236 break;
1237 }
1238
1239 if (current_driver_name[0])
1240 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1241 current_driver_name);
1242
1243
1244 return 1;
1245}
1246__setup("dma_debug_driver=", dma_debug_driver_setup);
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-03 13:43:15 -0500