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-rw-r--r--lib/dma-debug.c1297
1 files changed, 1297 insertions, 0 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
new file mode 100644
index 000000000000..58a9f9fc609a
--- /dev/null
+++ b/lib/dma-debug.c
@@ -0,0 +1,1297 @@
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 && dev->driver == current_driver)
160 return true;
161
162 /* driver filter on, but we can't filter on a NULL device... */
163 if (!dev)
164 return false;
165
166 if (current_driver || !current_driver_name[0])
167 return false;
168
169 /* driver filter on but not yet initialized */
170 drv = get_driver(dev->driver);
171 if (!drv)
172 return false;
173
174 /* lock to protect against change of current_driver_name */
175 read_lock_irqsave(&driver_name_lock, flags);
176
177 ret = false;
178 if (drv->name &&
179 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
180 current_driver = drv;
181 ret = true;
182 }
183
184 read_unlock_irqrestore(&driver_name_lock, flags);
185 put_driver(drv);
186
187 return ret;
188}
189
190#define err_printk(dev, entry, format, arg...) do { \
191 error_count += 1; \
192 if (driver_filter(dev) && \
193 (show_all_errors || show_num_errors > 0)) { \
194 WARN(1, "%s %s: " format, \
195 dev ? dev_driver_string(dev) : "NULL", \
196 dev ? dev_name(dev) : "NULL", ## arg); \
197 dump_entry_trace(entry); \
198 } \
199 if (!show_all_errors && show_num_errors > 0) \
200 show_num_errors -= 1; \
201 } while (0);
202
203/*
204 * Hash related functions
205 *
206 * Every DMA-API request is saved into a struct dma_debug_entry. To
207 * have quick access to these structs they are stored into a hash.
208 */
209static int hash_fn(struct dma_debug_entry *entry)
210{
211 /*
212 * Hash function is based on the dma address.
213 * We use bits 20-27 here as the index into the hash
214 */
215 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
216}
217
218/*
219 * Request exclusive access to a hash bucket for a given dma_debug_entry.
220 */
221static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
222 unsigned long *flags)
223{
224 int idx = hash_fn(entry);
225 unsigned long __flags;
226
227 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
228 *flags = __flags;
229 return &dma_entry_hash[idx];
230}
231
232/*
233 * Give up exclusive access to the hash bucket
234 */
235static void put_hash_bucket(struct hash_bucket *bucket,
236 unsigned long *flags)
237{
238 unsigned long __flags = *flags;
239
240 spin_unlock_irqrestore(&bucket->lock, __flags);
241}
242
243/*
244 * Search a given entry in the hash bucket list
245 */
246static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
247 struct dma_debug_entry *ref)
248{
249 struct dma_debug_entry *entry, *ret = NULL;
250 int matches = 0, match_lvl, last_lvl = 0;
251
252 list_for_each_entry(entry, &bucket->list, list) {
253 if ((entry->dev_addr != ref->dev_addr) ||
254 (entry->dev != ref->dev))
255 continue;
256
257 /*
258 * Some drivers map the same physical address multiple
259 * times. Without a hardware IOMMU this results in the
260 * same device addresses being put into the dma-debug
261 * hash multiple times too. This can result in false
262 * positives being reported. Therfore we implement a
263 * best-fit algorithm here which returns the entry from
264 * the hash which fits best to the reference value
265 * instead of the first-fit.
266 */
267 matches += 1;
268 match_lvl = 0;
269 entry->size == ref->size ? ++match_lvl : 0;
270 entry->type == ref->type ? ++match_lvl : 0;
271 entry->direction == ref->direction ? ++match_lvl : 0;
272 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
273
274 if (match_lvl == 4) {
275 /* perfect-fit - return the result */
276 return entry;
277 } else if (match_lvl > last_lvl) {
278 /*
279 * We found an entry that fits better then the
280 * previous one
281 */
282 last_lvl = match_lvl;
283 ret = entry;
284 }
285 }
286
287 /*
288 * If we have multiple matches but no perfect-fit, just return
289 * NULL.
290 */
291 ret = (matches == 1) ? ret : NULL;
292
293 return ret;
294}
295
296/*
297 * Add an entry to a hash bucket
298 */
299static void hash_bucket_add(struct hash_bucket *bucket,
300 struct dma_debug_entry *entry)
301{
302 list_add_tail(&entry->list, &bucket->list);
303}
304
305/*
306 * Remove entry from a hash bucket list
307 */
308static void hash_bucket_del(struct dma_debug_entry *entry)
309{
310 list_del(&entry->list);
311}
312
313/*
314 * Dump mapping entries for debugging purposes
315 */
316void debug_dma_dump_mappings(struct device *dev)
317{
318 int idx;
319
320 for (idx = 0; idx < HASH_SIZE; idx++) {
321 struct hash_bucket *bucket = &dma_entry_hash[idx];
322 struct dma_debug_entry *entry;
323 unsigned long flags;
324
325 spin_lock_irqsave(&bucket->lock, flags);
326
327 list_for_each_entry(entry, &bucket->list, list) {
328 if (!dev || dev == entry->dev) {
329 dev_info(entry->dev,
330 "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
331 type2name[entry->type], idx,
332 (unsigned long long)entry->paddr,
333 entry->dev_addr, entry->size,
334 dir2name[entry->direction]);
335 }
336 }
337
338 spin_unlock_irqrestore(&bucket->lock, flags);
339 }
340}
341EXPORT_SYMBOL(debug_dma_dump_mappings);
342
343/*
344 * Wrapper function for adding an entry to the hash.
345 * This function takes care of locking itself.
346 */
347static void add_dma_entry(struct dma_debug_entry *entry)
348{
349 struct hash_bucket *bucket;
350 unsigned long flags;
351
352 bucket = get_hash_bucket(entry, &flags);
353 hash_bucket_add(bucket, entry);
354 put_hash_bucket(bucket, &flags);
355}
356
357static struct dma_debug_entry *__dma_entry_alloc(void)
358{
359 struct dma_debug_entry *entry;
360
361 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
362 list_del(&entry->list);
363 memset(entry, 0, sizeof(*entry));
364
365 num_free_entries -= 1;
366 if (num_free_entries < min_free_entries)
367 min_free_entries = num_free_entries;
368
369 return entry;
370}
371
372/* struct dma_entry allocator
373 *
374 * The next two functions implement the allocator for
375 * struct dma_debug_entries.
376 */
377static struct dma_debug_entry *dma_entry_alloc(void)
378{
379 struct dma_debug_entry *entry = NULL;
380 unsigned long flags;
381
382 spin_lock_irqsave(&free_entries_lock, flags);
383
384 if (list_empty(&free_entries)) {
385 pr_err("DMA-API: debugging out of memory - disabling\n");
386 global_disable = true;
387 goto out;
388 }
389
390 entry = __dma_entry_alloc();
391
392#ifdef CONFIG_STACKTRACE
393 entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
394 entry->stacktrace.entries = entry->st_entries;
395 entry->stacktrace.skip = 2;
396 save_stack_trace(&entry->stacktrace);
397#endif
398
399out:
400 spin_unlock_irqrestore(&free_entries_lock, flags);
401
402 return entry;
403}
404
405static void dma_entry_free(struct dma_debug_entry *entry)
406{
407 unsigned long flags;
408
409 /*
410 * add to beginning of the list - this way the entries are
411 * more likely cache hot when they are reallocated.
412 */
413 spin_lock_irqsave(&free_entries_lock, flags);
414 list_add(&entry->list, &free_entries);
415 num_free_entries += 1;
416 spin_unlock_irqrestore(&free_entries_lock, flags);
417}
418
419int dma_debug_resize_entries(u32 num_entries)
420{
421 int i, delta, ret = 0;
422 unsigned long flags;
423 struct dma_debug_entry *entry;
424 LIST_HEAD(tmp);
425
426 spin_lock_irqsave(&free_entries_lock, flags);
427
428 if (nr_total_entries < num_entries) {
429 delta = num_entries - nr_total_entries;
430
431 spin_unlock_irqrestore(&free_entries_lock, flags);
432
433 for (i = 0; i < delta; i++) {
434 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
435 if (!entry)
436 break;
437
438 list_add_tail(&entry->list, &tmp);
439 }
440
441 spin_lock_irqsave(&free_entries_lock, flags);
442
443 list_splice(&tmp, &free_entries);
444 nr_total_entries += i;
445 num_free_entries += i;
446 } else {
447 delta = nr_total_entries - num_entries;
448
449 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
450 entry = __dma_entry_alloc();
451 kfree(entry);
452 }
453
454 nr_total_entries -= i;
455 }
456
457 if (nr_total_entries != num_entries)
458 ret = 1;
459
460 spin_unlock_irqrestore(&free_entries_lock, flags);
461
462 return ret;
463}
464EXPORT_SYMBOL(dma_debug_resize_entries);
465
466/*
467 * DMA-API debugging init code
468 *
469 * The init code does two things:
470 * 1. Initialize core data structures
471 * 2. Preallocate a given number of dma_debug_entry structs
472 */
473
474static int prealloc_memory(u32 num_entries)
475{
476 struct dma_debug_entry *entry, *next_entry;
477 int i;
478
479 for (i = 0; i < num_entries; ++i) {
480 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
481 if (!entry)
482 goto out_err;
483
484 list_add_tail(&entry->list, &free_entries);
485 }
486
487 num_free_entries = num_entries;
488 min_free_entries = num_entries;
489
490 pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
491
492 return 0;
493
494out_err:
495
496 list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
497 list_del(&entry->list);
498 kfree(entry);
499 }
500
501 return -ENOMEM;
502}
503
504static ssize_t filter_read(struct file *file, char __user *user_buf,
505 size_t count, loff_t *ppos)
506{
507 char buf[NAME_MAX_LEN + 1];
508 unsigned long flags;
509 int len;
510
511 if (!current_driver_name[0])
512 return 0;
513
514 /*
515 * We can't copy to userspace directly because current_driver_name can
516 * only be read under the driver_name_lock with irqs disabled. So
517 * create a temporary copy first.
518 */
519 read_lock_irqsave(&driver_name_lock, flags);
520 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
521 read_unlock_irqrestore(&driver_name_lock, flags);
522
523 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
524}
525
526static ssize_t filter_write(struct file *file, const char __user *userbuf,
527 size_t count, loff_t *ppos)
528{
529 char buf[NAME_MAX_LEN];
530 unsigned long flags;
531 size_t len;
532 int i;
533
534 /*
535 * We can't copy from userspace directly. Access to
536 * current_driver_name is protected with a write_lock with irqs
537 * disabled. Since copy_from_user can fault and may sleep we
538 * need to copy to temporary buffer first
539 */
540 len = min(count, (size_t)(NAME_MAX_LEN - 1));
541 if (copy_from_user(buf, userbuf, len))
542 return -EFAULT;
543
544 buf[len] = 0;
545
546 write_lock_irqsave(&driver_name_lock, flags);
547
548 /*
549 * Now handle the string we got from userspace very carefully.
550 * The rules are:
551 * - only use the first token we got
552 * - token delimiter is everything looking like a space
553 * character (' ', '\n', '\t' ...)
554 *
555 */
556 if (!isalnum(buf[0])) {
557 /*
558 * If the first character userspace gave us is not
559 * alphanumerical then assume the filter should be
560 * switched off.
561 */
562 if (current_driver_name[0])
563 pr_info("DMA-API: switching off dma-debug driver filter\n");
564 current_driver_name[0] = 0;
565 current_driver = NULL;
566 goto out_unlock;
567 }
568
569 /*
570 * Now parse out the first token and use it as the name for the
571 * driver to filter for.
572 */
573 for (i = 0; i < NAME_MAX_LEN; ++i) {
574 current_driver_name[i] = buf[i];
575 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
576 break;
577 }
578 current_driver_name[i] = 0;
579 current_driver = NULL;
580
581 pr_info("DMA-API: enable driver filter for driver [%s]\n",
582 current_driver_name);
583
584out_unlock:
585 write_unlock_irqrestore(&driver_name_lock, flags);
586
587 return count;
588}
589
590const struct file_operations filter_fops = {
591 .read = filter_read,
592 .write = filter_write,
593};
594
595static int dma_debug_fs_init(void)
596{
597 dma_debug_dent = debugfs_create_dir("dma-api", NULL);
598 if (!dma_debug_dent) {
599 pr_err("DMA-API: can not create debugfs directory\n");
600 return -ENOMEM;
601 }
602
603 global_disable_dent = debugfs_create_bool("disabled", 0444,
604 dma_debug_dent,
605 (u32 *)&global_disable);
606 if (!global_disable_dent)
607 goto out_err;
608
609 error_count_dent = debugfs_create_u32("error_count", 0444,
610 dma_debug_dent, &error_count);
611 if (!error_count_dent)
612 goto out_err;
613
614 show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
615 dma_debug_dent,
616 &show_all_errors);
617 if (!show_all_errors_dent)
618 goto out_err;
619
620 show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
621 dma_debug_dent,
622 &show_num_errors);
623 if (!show_num_errors_dent)
624 goto out_err;
625
626 num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
627 dma_debug_dent,
628 &num_free_entries);
629 if (!num_free_entries_dent)
630 goto out_err;
631
632 min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
633 dma_debug_dent,
634 &min_free_entries);
635 if (!min_free_entries_dent)
636 goto out_err;
637
638 filter_dent = debugfs_create_file("driver_filter", 0644,
639 dma_debug_dent, NULL, &filter_fops);
640 if (!filter_dent)
641 goto out_err;
642
643 return 0;
644
645out_err:
646 debugfs_remove_recursive(dma_debug_dent);
647
648 return -ENOMEM;
649}
650
651static int device_dma_allocations(struct device *dev)
652{
653 struct dma_debug_entry *entry;
654 unsigned long flags;
655 int count = 0, i;
656
657 local_irq_save(flags);
658
659 for (i = 0; i < HASH_SIZE; ++i) {
660 spin_lock(&dma_entry_hash[i].lock);
661 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
662 if (entry->dev == dev)
663 count += 1;
664 }
665 spin_unlock(&dma_entry_hash[i].lock);
666 }
667
668 local_irq_restore(flags);
669
670 return count;
671}
672
673static int dma_debug_device_change(struct notifier_block *nb,
674 unsigned long action, void *data)
675{
676 struct device *dev = data;
677 int count;
678
679
680 switch (action) {
681 case BUS_NOTIFY_UNBOUND_DRIVER:
682 count = device_dma_allocations(dev);
683 if (count == 0)
684 break;
685 err_printk(dev, NULL, "DMA-API: device driver has pending "
686 "DMA allocations while released from device "
687 "[count=%d]\n", count);
688 break;
689 default:
690 break;
691 }
692
693 return 0;
694}
695
696void dma_debug_add_bus(struct bus_type *bus)
697{
698 struct notifier_block *nb;
699
700 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
701 if (nb == NULL) {
702 pr_err("dma_debug_add_bus: out of memory\n");
703 return;
704 }
705
706 nb->notifier_call = dma_debug_device_change;
707
708 bus_register_notifier(bus, nb);
709}
710
711/*
712 * Let the architectures decide how many entries should be preallocated.
713 */
714void dma_debug_init(u32 num_entries)
715{
716 int i;
717
718 if (global_disable)
719 return;
720
721 for (i = 0; i < HASH_SIZE; ++i) {
722 INIT_LIST_HEAD(&dma_entry_hash[i].list);
723 spin_lock_init(&dma_entry_hash[i].lock);
724 }
725
726 if (dma_debug_fs_init() != 0) {
727 pr_err("DMA-API: error creating debugfs entries - disabling\n");
728 global_disable = true;
729
730 return;
731 }
732
733 if (req_entries)
734 num_entries = req_entries;
735
736 if (prealloc_memory(num_entries) != 0) {
737 pr_err("DMA-API: debugging out of memory error - disabled\n");
738 global_disable = true;
739
740 return;
741 }
742
743 nr_total_entries = num_free_entries;
744
745 pr_info("DMA-API: debugging enabled by kernel config\n");
746}
747
748static __init int dma_debug_cmdline(char *str)
749{
750 if (!str)
751 return -EINVAL;
752
753 if (strncmp(str, "off", 3) == 0) {
754 pr_info("DMA-API: debugging disabled on kernel command line\n");
755 global_disable = true;
756 }
757
758 return 0;
759}
760
761static __init int dma_debug_entries_cmdline(char *str)
762{
763 int res;
764
765 if (!str)
766 return -EINVAL;
767
768 res = get_option(&str, &req_entries);
769
770 if (!res)
771 req_entries = 0;
772
773 return 0;
774}
775
776__setup("dma_debug=", dma_debug_cmdline);
777__setup("dma_debug_entries=", dma_debug_entries_cmdline);
778
779static void check_unmap(struct dma_debug_entry *ref)
780{
781 struct dma_debug_entry *entry;
782 struct hash_bucket *bucket;
783 unsigned long flags;
784
785 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
786 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
787 "to free an invalid DMA memory address\n");
788 return;
789 }
790
791 bucket = get_hash_bucket(ref, &flags);
792 entry = hash_bucket_find(bucket, ref);
793
794 if (!entry) {
795 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
796 "to free DMA memory it has not allocated "
797 "[device address=0x%016llx] [size=%llu bytes]\n",
798 ref->dev_addr, ref->size);
799 goto out;
800 }
801
802 if (ref->size != entry->size) {
803 err_printk(ref->dev, entry, "DMA-API: device driver frees "
804 "DMA memory with different size "
805 "[device address=0x%016llx] [map size=%llu bytes] "
806 "[unmap size=%llu bytes]\n",
807 ref->dev_addr, entry->size, ref->size);
808 }
809
810 if (ref->type != entry->type) {
811 err_printk(ref->dev, entry, "DMA-API: device driver frees "
812 "DMA memory with wrong function "
813 "[device address=0x%016llx] [size=%llu bytes] "
814 "[mapped as %s] [unmapped as %s]\n",
815 ref->dev_addr, ref->size,
816 type2name[entry->type], type2name[ref->type]);
817 } else if ((entry->type == dma_debug_coherent) &&
818 (ref->paddr != entry->paddr)) {
819 err_printk(ref->dev, entry, "DMA-API: device driver frees "
820 "DMA memory with different CPU address "
821 "[device address=0x%016llx] [size=%llu bytes] "
822 "[cpu alloc address=%p] [cpu free address=%p]",
823 ref->dev_addr, ref->size,
824 (void *)entry->paddr, (void *)ref->paddr);
825 }
826
827 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
828 ref->sg_call_ents != entry->sg_call_ents) {
829 err_printk(ref->dev, entry, "DMA-API: device driver frees "
830 "DMA sg list with different entry count "
831 "[map count=%d] [unmap count=%d]\n",
832 entry->sg_call_ents, ref->sg_call_ents);
833 }
834
835 /*
836 * This may be no bug in reality - but most implementations of the
837 * DMA API don't handle this properly, so check for it here
838 */
839 if (ref->direction != entry->direction) {
840 err_printk(ref->dev, entry, "DMA-API: device driver frees "
841 "DMA memory with different direction "
842 "[device address=0x%016llx] [size=%llu bytes] "
843 "[mapped with %s] [unmapped with %s]\n",
844 ref->dev_addr, ref->size,
845 dir2name[entry->direction],
846 dir2name[ref->direction]);
847 }
848
849 hash_bucket_del(entry);
850 dma_entry_free(entry);
851
852out:
853 put_hash_bucket(bucket, &flags);
854}
855
856static void check_for_stack(struct device *dev, void *addr)
857{
858 if (object_is_on_stack(addr))
859 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
860 "stack [addr=%p]\n", addr);
861}
862
863static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
864{
865 unsigned long a1 = (unsigned long)addr;
866 unsigned long b1 = a1 + len;
867 unsigned long a2 = (unsigned long)start;
868 unsigned long b2 = (unsigned long)end;
869
870 return !(b1 <= a2 || a1 >= b2);
871}
872
873static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
874{
875 if (overlap(addr, len, _text, _etext) ||
876 overlap(addr, len, __start_rodata, __end_rodata))
877 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
878}
879
880static void check_sync(struct device *dev,
881 struct dma_debug_entry *ref,
882 bool to_cpu)
883{
884 struct dma_debug_entry *entry;
885 struct hash_bucket *bucket;
886 unsigned long flags;
887
888 bucket = get_hash_bucket(ref, &flags);
889
890 entry = hash_bucket_find(bucket, ref);
891
892 if (!entry) {
893 err_printk(dev, NULL, "DMA-API: device driver tries "
894 "to sync DMA memory it has not allocated "
895 "[device address=0x%016llx] [size=%llu bytes]\n",
896 (unsigned long long)ref->dev_addr, ref->size);
897 goto out;
898 }
899
900 if (ref->size > entry->size) {
901 err_printk(dev, entry, "DMA-API: device driver syncs"
902 " DMA memory outside allocated range "
903 "[device address=0x%016llx] "
904 "[allocation size=%llu bytes] "
905 "[sync offset+size=%llu]\n",
906 entry->dev_addr, entry->size,
907 ref->size);
908 }
909
910 if (ref->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)ref->dev_addr, entry->size,
916 dir2name[entry->direction],
917 dir2name[ref->direction]);
918 }
919
920 if (entry->direction == DMA_BIDIRECTIONAL)
921 goto out;
922
923 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
924 !(ref->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)ref->dev_addr, entry->size,
930 dir2name[entry->direction],
931 dir2name[ref->direction]);
932
933 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
934 !(ref->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)ref->dev_addr, entry->size,
940 dir2name[entry->direction],
941 dir2name[ref->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 = page_address(page) + offset;
976
977 check_for_stack(dev, addr);
978 check_for_illegal_area(dev, addr, size);
979 }
980
981 add_dma_entry(entry);
982}
983EXPORT_SYMBOL(debug_dma_map_page);
984
985void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
986 size_t size, int direction, bool map_single)
987{
988 struct dma_debug_entry ref = {
989 .type = dma_debug_page,
990 .dev = dev,
991 .dev_addr = addr,
992 .size = size,
993 .direction = direction,
994 };
995
996 if (unlikely(global_disable))
997 return;
998
999 if (map_single)
1000 ref.type = dma_debug_single;
1001
1002 check_unmap(&ref);
1003}
1004EXPORT_SYMBOL(debug_dma_unmap_page);
1005
1006void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1007 int nents, int mapped_ents, int direction)
1008{
1009 struct dma_debug_entry *entry;
1010 struct scatterlist *s;
1011 int i;
1012
1013 if (unlikely(global_disable))
1014 return;
1015
1016 for_each_sg(sg, s, mapped_ents, i) {
1017 entry = dma_entry_alloc();
1018 if (!entry)
1019 return;
1020
1021 entry->type = dma_debug_sg;
1022 entry->dev = dev;
1023 entry->paddr = sg_phys(s);
1024 entry->size = sg_dma_len(s);
1025 entry->dev_addr = sg_dma_address(s);
1026 entry->direction = direction;
1027 entry->sg_call_ents = nents;
1028 entry->sg_mapped_ents = mapped_ents;
1029
1030 if (!PageHighMem(sg_page(s))) {
1031 check_for_stack(dev, sg_virt(s));
1032 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1033 }
1034
1035 add_dma_entry(entry);
1036 }
1037}
1038EXPORT_SYMBOL(debug_dma_map_sg);
1039
1040static int get_nr_mapped_entries(struct device *dev,
1041 struct dma_debug_entry *ref)
1042{
1043 struct dma_debug_entry *entry;
1044 struct hash_bucket *bucket;
1045 unsigned long flags;
1046 int mapped_ents;
1047
1048 bucket = get_hash_bucket(ref, &flags);
1049 entry = hash_bucket_find(bucket, ref);
1050 mapped_ents = 0;
1051
1052 if (entry)
1053 mapped_ents = entry->sg_mapped_ents;
1054 put_hash_bucket(bucket, &flags);
1055
1056 return mapped_ents;
1057}
1058
1059void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1060 int nelems, int dir)
1061{
1062 struct scatterlist *s;
1063 int mapped_ents = 0, i;
1064
1065 if (unlikely(global_disable))
1066 return;
1067
1068 for_each_sg(sglist, s, nelems, i) {
1069
1070 struct dma_debug_entry ref = {
1071 .type = dma_debug_sg,
1072 .dev = dev,
1073 .paddr = sg_phys(s),
1074 .dev_addr = sg_dma_address(s),
1075 .size = sg_dma_len(s),
1076 .direction = dir,
1077 .sg_call_ents = nelems,
1078 };
1079
1080 if (mapped_ents && i >= mapped_ents)
1081 break;
1082
1083 if (!i)
1084 mapped_ents = get_nr_mapped_entries(dev, &ref);
1085
1086 check_unmap(&ref);
1087 }
1088}
1089EXPORT_SYMBOL(debug_dma_unmap_sg);
1090
1091void debug_dma_alloc_coherent(struct device *dev, size_t size,
1092 dma_addr_t dma_addr, void *virt)
1093{
1094 struct dma_debug_entry *entry;
1095
1096 if (unlikely(global_disable))
1097 return;
1098
1099 if (unlikely(virt == NULL))
1100 return;
1101
1102 entry = dma_entry_alloc();
1103 if (!entry)
1104 return;
1105
1106 entry->type = dma_debug_coherent;
1107 entry->dev = dev;
1108 entry->paddr = virt_to_phys(virt);
1109 entry->size = size;
1110 entry->dev_addr = dma_addr;
1111 entry->direction = DMA_BIDIRECTIONAL;
1112
1113 add_dma_entry(entry);
1114}
1115EXPORT_SYMBOL(debug_dma_alloc_coherent);
1116
1117void debug_dma_free_coherent(struct device *dev, size_t size,
1118 void *virt, dma_addr_t addr)
1119{
1120 struct dma_debug_entry ref = {
1121 .type = dma_debug_coherent,
1122 .dev = dev,
1123 .paddr = virt_to_phys(virt),
1124 .dev_addr = addr,
1125 .size = size,
1126 .direction = DMA_BIDIRECTIONAL,
1127 };
1128
1129 if (unlikely(global_disable))
1130 return;
1131
1132 check_unmap(&ref);
1133}
1134EXPORT_SYMBOL(debug_dma_free_coherent);
1135
1136void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1137 size_t size, int direction)
1138{
1139 struct dma_debug_entry ref;
1140
1141 if (unlikely(global_disable))
1142 return;
1143
1144 ref.type = dma_debug_single;
1145 ref.dev = dev;
1146 ref.dev_addr = dma_handle;
1147 ref.size = size;
1148 ref.direction = direction;
1149 ref.sg_call_ents = 0;
1150
1151 check_sync(dev, &ref, true);
1152}
1153EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1154
1155void debug_dma_sync_single_for_device(struct device *dev,
1156 dma_addr_t dma_handle, size_t size,
1157 int direction)
1158{
1159 struct dma_debug_entry ref;
1160
1161 if (unlikely(global_disable))
1162 return;
1163
1164 ref.type = dma_debug_single;
1165 ref.dev = dev;
1166 ref.dev_addr = dma_handle;
1167 ref.size = size;
1168 ref.direction = direction;
1169 ref.sg_call_ents = 0;
1170
1171 check_sync(dev, &ref, false);
1172}
1173EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1174
1175void debug_dma_sync_single_range_for_cpu(struct device *dev,
1176 dma_addr_t dma_handle,
1177 unsigned long offset, size_t size,
1178 int direction)
1179{
1180 struct dma_debug_entry ref;
1181
1182 if (unlikely(global_disable))
1183 return;
1184
1185 ref.type = dma_debug_single;
1186 ref.dev = dev;
1187 ref.dev_addr = dma_handle;
1188 ref.size = offset + size;
1189 ref.direction = direction;
1190 ref.sg_call_ents = 0;
1191
1192 check_sync(dev, &ref, true);
1193}
1194EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1195
1196void debug_dma_sync_single_range_for_device(struct device *dev,
1197 dma_addr_t dma_handle,
1198 unsigned long offset,
1199 size_t size, int direction)
1200{
1201 struct dma_debug_entry ref;
1202
1203 if (unlikely(global_disable))
1204 return;
1205
1206 ref.type = dma_debug_single;
1207 ref.dev = dev;
1208 ref.dev_addr = dma_handle;
1209 ref.size = offset + size;
1210 ref.direction = direction;
1211 ref.sg_call_ents = 0;
1212
1213 check_sync(dev, &ref, false);
1214}
1215EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1216
1217void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1218 int nelems, int direction)
1219{
1220 struct scatterlist *s;
1221 int mapped_ents = 0, i;
1222
1223 if (unlikely(global_disable))
1224 return;
1225
1226 for_each_sg(sg, s, nelems, i) {
1227
1228 struct dma_debug_entry ref = {
1229 .type = dma_debug_sg,
1230 .dev = dev,
1231 .paddr = sg_phys(s),
1232 .dev_addr = sg_dma_address(s),
1233 .size = sg_dma_len(s),
1234 .direction = direction,
1235 .sg_call_ents = nelems,
1236 };
1237
1238 if (!i)
1239 mapped_ents = get_nr_mapped_entries(dev, &ref);
1240
1241 if (i >= mapped_ents)
1242 break;
1243
1244 check_sync(dev, &ref, true);
1245 }
1246}
1247EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1248
1249void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1250 int nelems, int direction)
1251{
1252 struct scatterlist *s;
1253 int mapped_ents = 0, i;
1254
1255 if (unlikely(global_disable))
1256 return;
1257
1258 for_each_sg(sg, s, nelems, i) {
1259
1260 struct dma_debug_entry ref = {
1261 .type = dma_debug_sg,
1262 .dev = dev,
1263 .paddr = sg_phys(s),
1264 .dev_addr = sg_dma_address(s),
1265 .size = sg_dma_len(s),
1266 .direction = direction,
1267 .sg_call_ents = nelems,
1268 };
1269 if (!i)
1270 mapped_ents = get_nr_mapped_entries(dev, &ref);
1271
1272 if (i >= mapped_ents)
1273 break;
1274
1275 check_sync(dev, &ref, false);
1276 }
1277}
1278EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1279
1280static int __init dma_debug_driver_setup(char *str)
1281{
1282 int i;
1283
1284 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1285 current_driver_name[i] = *str;
1286 if (*str == 0)
1287 break;
1288 }
1289
1290 if (current_driver_name[0])
1291 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1292 current_driver_name);
1293
1294
1295 return 1;
1296}
1297__setup("dma_debug_driver=", dma_debug_driver_setup);
generated by cgit v1.2.2 (git 2.25.0) at 2025-05-07 03:47:10 -0400