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Revert "ALSA: hda - Shut up pins at power-saving mode with Conexnat codecs"
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / lib / dma-debug.c
blob5e396accd3d02a8dce6d06cc2d6020e311b308b0
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/export.h>
28 #include <linux/device.h>
29 #include <linux/types.h>
30 #include <linux/sched.h>
31 #include <linux/ctype.h>
32 #include <linux/list.h>
33 #include <linux/slab.h>
34
35 #include <asm/sections.h>
36
37 #define HASH_SIZE 1024ULL
38 #define HASH_FN_SHIFT 13
39 #define HASH_FN_MASK (HASH_SIZE - 1)
40
41 enum {
42 dma_debug_single,
43 dma_debug_page,
44 dma_debug_sg,
45 dma_debug_coherent,
46 };
47
48 enum map_err_types {
49 MAP_ERR_CHECK_NOT_APPLICABLE,
50 MAP_ERR_NOT_CHECKED,
51 MAP_ERR_CHECKED,
52 };
53
54 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
55
56 struct dma_debug_entry {
57 struct list_head list;
58 struct device *dev;
59 int type;
60 phys_addr_t paddr;
61 u64 dev_addr;
62 u64 size;
63 int direction;
64 int sg_call_ents;
65 int sg_mapped_ents;
66 enum map_err_types map_err_type;
67 #ifdef CONFIG_STACKTRACE
68 struct stack_trace stacktrace;
69 unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
70 #endif
71 };
72
73 typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
74
75 struct hash_bucket {
76 struct list_head list;
77 spinlock_t lock;
78 } ____cacheline_aligned_in_smp;
79
80 /* Hash list to save the allocated dma addresses */
81 static struct hash_bucket dma_entry_hash[HASH_SIZE];
82 /* List of pre-allocated dma_debug_entry's */
83 static LIST_HEAD(free_entries);
84 /* Lock for the list above */
85 static DEFINE_SPINLOCK(free_entries_lock);
86
87 /* Global disable flag - will be set in case of an error */
88 static u32 global_disable __read_mostly;
89
90 /* Global error count */
91 static u32 error_count;
92
93 /* Global error show enable*/
94 static u32 show_all_errors __read_mostly;
95 /* Number of errors to show */
96 static u32 show_num_errors = 1;
97
98 static u32 num_free_entries;
99 static u32 min_free_entries;
100 static u32 nr_total_entries;
101
102 /* number of preallocated entries requested by kernel cmdline */
103 static u32 req_entries;
104
105 /* debugfs dentry's for the stuff above */
106 static struct dentry *dma_debug_dent __read_mostly;
107 static struct dentry *global_disable_dent __read_mostly;
108 static struct dentry *error_count_dent __read_mostly;
109 static struct dentry *show_all_errors_dent __read_mostly;
110 static struct dentry *show_num_errors_dent __read_mostly;
111 static struct dentry *num_free_entries_dent __read_mostly;
112 static struct dentry *min_free_entries_dent __read_mostly;
113 static struct dentry *filter_dent __read_mostly;
114
115 /* per-driver filter related state */
116
117 #define NAME_MAX_LEN 64
118
119 static char current_driver_name[NAME_MAX_LEN] __read_mostly;
120 static struct device_driver *current_driver __read_mostly;
121
122 static DEFINE_RWLOCK(driver_name_lock);
123
124 static const char *const maperr2str[] = {
125 [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
126 [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
127 [MAP_ERR_CHECKED] = "dma map error checked",
128 };
129
130 static const char *type2name[4] = { "single", "page",
131 "scather-gather", "coherent" };
132
133 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
134 "DMA_FROM_DEVICE", "DMA_NONE" };
135
136 /*
137 * The access to some variables in this macro is racy. We can't use atomic_t
138 * here because all these variables are exported to debugfs. Some of them even
139 * writeable. This is also the reason why a lock won't help much. But anyway,
140 * the races are no big deal. Here is why:
141 *
142 * error_count: the addition is racy, but the worst thing that can happen is
143 * that we don't count some errors
144 * show_num_errors: the subtraction is racy. Also no big deal because in
145 * worst case this will result in one warning more in the
146 * system log than the user configured. This variable is
147 * writeable via debugfs.
148 */
149 static inline void dump_entry_trace(struct dma_debug_entry *entry)
150 {
151 #ifdef CONFIG_STACKTRACE
152 if (entry) {
153 pr_warning("Mapped at:\n");
154 print_stack_trace(&entry->stacktrace, 0);
155 }
156 #endif
157 }
158
159 static bool driver_filter(struct device *dev)
160 {
161 struct device_driver *drv;
162 unsigned long flags;
163 bool ret;
164
165 /* driver filter off */
166 if (likely(!current_driver_name[0]))
167 return true;
168
169 /* driver filter on and initialized */
170 if (current_driver && dev && dev->driver == current_driver)
171 return true;
172
173 /* driver filter on, but we can't filter on a NULL device... */
174 if (!dev)
175 return false;
176
177 if (current_driver || !current_driver_name[0])
178 return false;
179
180 /* driver filter on but not yet initialized */
181 drv = dev->driver;
182 if (!drv)
183 return false;
184
185 /* lock to protect against change of current_driver_name */
186 read_lock_irqsave(&driver_name_lock, flags);
187
188 ret = false;
189 if (drv->name &&
190 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
191 current_driver = drv;
192 ret = true;
193 }
194
195 read_unlock_irqrestore(&driver_name_lock, flags);
196
197 return ret;
198 }
199
200 #define err_printk(dev, entry, format, arg...) do { \
201 error_count += 1; \
202 if (driver_filter(dev) && \
203 (show_all_errors || show_num_errors > 0)) { \
204 WARN(1, "%s %s: " format, \
205 dev ? dev_driver_string(dev) : "NULL", \
206 dev ? dev_name(dev) : "NULL", ## arg); \
207 dump_entry_trace(entry); \
208 } \
209 if (!show_all_errors && show_num_errors > 0) \
210 show_num_errors -= 1; \
211 } while (0);
212
213 /*
214 * Hash related functions
215 *
216 * Every DMA-API request is saved into a struct dma_debug_entry. To
217 * have quick access to these structs they are stored into a hash.
218 */
219 static int hash_fn(struct dma_debug_entry *entry)
220 {
221 /*
222 * Hash function is based on the dma address.
223 * We use bits 20-27 here as the index into the hash
224 */
225 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
226 }
227
228 /*
229 * Request exclusive access to a hash bucket for a given dma_debug_entry.
230 */
231 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
232 unsigned long *flags)
233 {
234 int idx = hash_fn(entry);
235 unsigned long __flags;
236
237 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
238 *flags = __flags;
239 return &dma_entry_hash[idx];
240 }
241
242 /*
243 * Give up exclusive access to the hash bucket
244 */
245 static void put_hash_bucket(struct hash_bucket *bucket,
246 unsigned long *flags)
247 {
248 unsigned long __flags = *flags;
249
250 spin_unlock_irqrestore(&bucket->lock, __flags);
251 }
252
253 static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
254 {
255 return ((a->dev_addr == b->dev_addr) &&
256 (a->dev == b->dev)) ? true : false;
257 }
258
259 static bool containing_match(struct dma_debug_entry *a,
260 struct dma_debug_entry *b)
261 {
262 if (a->dev != b->dev)
263 return false;
264
265 if ((b->dev_addr <= a->dev_addr) &&
266 ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
267 return true;
268
269 return false;
270 }
271
272 /*
273 * Search a given entry in the hash bucket list
274 */
275 static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
276 struct dma_debug_entry *ref,
277 match_fn match)
278 {
279 struct dma_debug_entry *entry, *ret = NULL;
280 int matches = 0, match_lvl, last_lvl = -1;
281
282 list_for_each_entry(entry, &bucket->list, list) {
283 if (!match(ref, entry))
284 continue;
285
286 /*
287 * Some drivers map the same physical address multiple
288 * times. Without a hardware IOMMU this results in the
289 * same device addresses being put into the dma-debug
290 * hash multiple times too. This can result in false
291 * positives being reported. Therefore we implement a
292 * best-fit algorithm here which returns the entry from
293 * the hash which fits best to the reference value
294 * instead of the first-fit.
295 */
296 matches += 1;
297 match_lvl = 0;
298 entry->size == ref->size ? ++match_lvl : 0;
299 entry->type == ref->type ? ++match_lvl : 0;
300 entry->direction == ref->direction ? ++match_lvl : 0;
301 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
302
303 if (match_lvl == 4) {
304 /* perfect-fit - return the result */
305 return entry;
306 } else if (match_lvl > last_lvl) {
307 /*
308 * We found an entry that fits better then the
309 * previous one or it is the 1st match.
310 */
311 last_lvl = match_lvl;
312 ret = entry;
313 }
314 }
315
316 /*
317 * If we have multiple matches but no perfect-fit, just return
318 * NULL.
319 */
320 ret = (matches == 1) ? ret : NULL;
321
322 return ret;
323 }
324
325 static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
326 struct dma_debug_entry *ref)
327 {
328 return __hash_bucket_find(bucket, ref, exact_match);
329 }
330
331 static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
332 struct dma_debug_entry *ref,
333 unsigned long *flags)
334 {
335
336 unsigned int max_range = dma_get_max_seg_size(ref->dev);
337 struct dma_debug_entry *entry, index = *ref;
338 unsigned int range = 0;
339
340 while (range <= max_range) {
341 entry = __hash_bucket_find(*bucket, &index, containing_match);
342
343 if (entry)
344 return entry;
345
346 /*
347 * Nothing found, go back a hash bucket
348 */
349 put_hash_bucket(*bucket, flags);
350 range += (1 << HASH_FN_SHIFT);
351 index.dev_addr -= (1 << HASH_FN_SHIFT);
352 *bucket = get_hash_bucket(&index, flags);
353 }
354
355 return NULL;
356 }
357
358 /*
359 * Add an entry to a hash bucket
360 */
361 static void hash_bucket_add(struct hash_bucket *bucket,
362 struct dma_debug_entry *entry)
363 {
364 list_add_tail(&entry->list, &bucket->list);
365 }
366
367 /*
368 * Remove entry from a hash bucket list
369 */
370 static void hash_bucket_del(struct dma_debug_entry *entry)
371 {
372 list_del(&entry->list);
373 }
374
375 /*
376 * Dump mapping entries for debugging purposes
377 */
378 void debug_dma_dump_mappings(struct device *dev)
379 {
380 int idx;
381
382 for (idx = 0; idx < HASH_SIZE; idx++) {
383 struct hash_bucket *bucket = &dma_entry_hash[idx];
384 struct dma_debug_entry *entry;
385 unsigned long flags;
386
387 spin_lock_irqsave(&bucket->lock, flags);
388
389 list_for_each_entry(entry, &bucket->list, list) {
390 if (!dev || dev == entry->dev) {
391 dev_info(entry->dev,
392 "%s idx %d P=%Lx D=%Lx L=%Lx %s %s\n",
393 type2name[entry->type], idx,
394 (unsigned long long)entry->paddr,
395 entry->dev_addr, entry->size,
396 dir2name[entry->direction],
397 maperr2str[entry->map_err_type]);
398 }
399 }
400
401 spin_unlock_irqrestore(&bucket->lock, flags);
402 }
403 }
404 EXPORT_SYMBOL(debug_dma_dump_mappings);
405
406 /*
407 * Wrapper function for adding an entry to the hash.
408 * This function takes care of locking itself.
409 */
410 static void add_dma_entry(struct dma_debug_entry *entry)
411 {
412 struct hash_bucket *bucket;
413 unsigned long flags;
414
415 bucket = get_hash_bucket(entry, &flags);
416 hash_bucket_add(bucket, entry);
417 put_hash_bucket(bucket, &flags);
418 }
419
420 static struct dma_debug_entry *__dma_entry_alloc(void)
421 {
422 struct dma_debug_entry *entry;
423
424 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
425 list_del(&entry->list);
426 memset(entry, 0, sizeof(*entry));
427
428 num_free_entries -= 1;
429 if (num_free_entries < min_free_entries)
430 min_free_entries = num_free_entries;
431
432 return entry;
433 }
434
435 /* struct dma_entry allocator
436 *
437 * The next two functions implement the allocator for
438 * struct dma_debug_entries.
439 */
440 static struct dma_debug_entry *dma_entry_alloc(void)
441 {
442 struct dma_debug_entry *entry;
443 unsigned long flags;
444
445 spin_lock_irqsave(&free_entries_lock, flags);
446
447 if (list_empty(&free_entries)) {
448 pr_err("DMA-API: debugging out of memory - disabling\n");
449 global_disable = true;
450 spin_unlock_irqrestore(&free_entries_lock, flags);
451 return NULL;
452 }
453
454 entry = __dma_entry_alloc();
455
456 spin_unlock_irqrestore(&free_entries_lock, flags);
457
458 #ifdef CONFIG_STACKTRACE
459 entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
460 entry->stacktrace.entries = entry->st_entries;
461 entry->stacktrace.skip = 2;
462 save_stack_trace(&entry->stacktrace);
463 #endif
464
465 return entry;
466 }
467
468 static void dma_entry_free(struct dma_debug_entry *entry)
469 {
470 unsigned long flags;
471
472 /*
473 * add to beginning of the list - this way the entries are
474 * more likely cache hot when they are reallocated.
475 */
476 spin_lock_irqsave(&free_entries_lock, flags);
477 list_add(&entry->list, &free_entries);
478 num_free_entries += 1;
479 spin_unlock_irqrestore(&free_entries_lock, flags);
480 }
481
482 int dma_debug_resize_entries(u32 num_entries)
483 {
484 int i, delta, ret = 0;
485 unsigned long flags;
486 struct dma_debug_entry *entry;
487 LIST_HEAD(tmp);
488
489 spin_lock_irqsave(&free_entries_lock, flags);
490
491 if (nr_total_entries < num_entries) {
492 delta = num_entries - nr_total_entries;
493
494 spin_unlock_irqrestore(&free_entries_lock, flags);
495
496 for (i = 0; i < delta; i++) {
497 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
498 if (!entry)
499 break;
500
501 list_add_tail(&entry->list, &tmp);
502 }
503
504 spin_lock_irqsave(&free_entries_lock, flags);
505
506 list_splice(&tmp, &free_entries);
507 nr_total_entries += i;
508 num_free_entries += i;
509 } else {
510 delta = nr_total_entries - num_entries;
511
512 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
513 entry = __dma_entry_alloc();
514 kfree(entry);
515 }
516
517 nr_total_entries -= i;
518 }
519
520 if (nr_total_entries != num_entries)
521 ret = 1;
522
523 spin_unlock_irqrestore(&free_entries_lock, flags);
524
525 return ret;
526 }
527 EXPORT_SYMBOL(dma_debug_resize_entries);
528
529 /*
530 * DMA-API debugging init code
531 *
532 * The init code does two things:
533 * 1. Initialize core data structures
534 * 2. Preallocate a given number of dma_debug_entry structs
535 */
536
537 static int prealloc_memory(u32 num_entries)
538 {
539 struct dma_debug_entry *entry, *next_entry;
540 int i;
541
542 for (i = 0; i < num_entries; ++i) {
543 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
544 if (!entry)
545 goto out_err;
546
547 list_add_tail(&entry->list, &free_entries);
548 }
549
550 num_free_entries = num_entries;
551 min_free_entries = num_entries;
552
553 pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
554
555 return 0;
556
557 out_err:
558
559 list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
560 list_del(&entry->list);
561 kfree(entry);
562 }
563
564 return -ENOMEM;
565 }
566
567 static ssize_t filter_read(struct file *file, char __user *user_buf,
568 size_t count, loff_t *ppos)
569 {
570 char buf[NAME_MAX_LEN + 1];
571 unsigned long flags;
572 int len;
573
574 if (!current_driver_name[0])
575 return 0;
576
577 /*
578 * We can't copy to userspace directly because current_driver_name can
579 * only be read under the driver_name_lock with irqs disabled. So
580 * create a temporary copy first.
581 */
582 read_lock_irqsave(&driver_name_lock, flags);
583 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
584 read_unlock_irqrestore(&driver_name_lock, flags);
585
586 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
587 }
588
589 static ssize_t filter_write(struct file *file, const char __user *userbuf,
590 size_t count, loff_t *ppos)
591 {
592 char buf[NAME_MAX_LEN];
593 unsigned long flags;
594 size_t len;
595 int i;
596
597 /*
598 * We can't copy from userspace directly. Access to
599 * current_driver_name is protected with a write_lock with irqs
600 * disabled. Since copy_from_user can fault and may sleep we
601 * need to copy to temporary buffer first
602 */
603 len = min(count, (size_t)(NAME_MAX_LEN - 1));
604 if (copy_from_user(buf, userbuf, len))
605 return -EFAULT;
606
607 buf[len] = 0;
608
609 write_lock_irqsave(&driver_name_lock, flags);
610
611 /*
612 * Now handle the string we got from userspace very carefully.
613 * The rules are:
614 * - only use the first token we got
615 * - token delimiter is everything looking like a space
616 * character (' ', '\n', '\t' ...)
617 *
618 */
619 if (!isalnum(buf[0])) {
620 /*
621 * If the first character userspace gave us is not
622 * alphanumerical then assume the filter should be
623 * switched off.
624 */
625 if (current_driver_name[0])
626 pr_info("DMA-API: switching off dma-debug driver filter\n");
627 current_driver_name[0] = 0;
628 current_driver = NULL;
629 goto out_unlock;
630 }
631
632 /*
633 * Now parse out the first token and use it as the name for the
634 * driver to filter for.
635 */
636 for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
637 current_driver_name[i] = buf[i];
638 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
639 break;
640 }
641 current_driver_name[i] = 0;
642 current_driver = NULL;
643
644 pr_info("DMA-API: enable driver filter for driver [%s]\n",
645 current_driver_name);
646
647 out_unlock:
648 write_unlock_irqrestore(&driver_name_lock, flags);
649
650 return count;
651 }
652
653 static const struct file_operations filter_fops = {
654 .read = filter_read,
655 .write = filter_write,
656 .llseek = default_llseek,
657 };
658
659 static int dma_debug_fs_init(void)
660 {
661 dma_debug_dent = debugfs_create_dir("dma-api", NULL);
662 if (!dma_debug_dent) {
663 pr_err("DMA-API: can not create debugfs directory\n");
664 return -ENOMEM;
665 }
666
667 global_disable_dent = debugfs_create_bool("disabled", 0444,
668 dma_debug_dent,
669 &global_disable);
670 if (!global_disable_dent)
671 goto out_err;
672
673 error_count_dent = debugfs_create_u32("error_count", 0444,
674 dma_debug_dent, &error_count);
675 if (!error_count_dent)
676 goto out_err;
677
678 show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
679 dma_debug_dent,
680 &show_all_errors);
681 if (!show_all_errors_dent)
682 goto out_err;
683
684 show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
685 dma_debug_dent,
686 &show_num_errors);
687 if (!show_num_errors_dent)
688 goto out_err;
689
690 num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
691 dma_debug_dent,
692 &num_free_entries);
693 if (!num_free_entries_dent)
694 goto out_err;
695
696 min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
697 dma_debug_dent,
698 &min_free_entries);
699 if (!min_free_entries_dent)
700 goto out_err;
701
702 filter_dent = debugfs_create_file("driver_filter", 0644,
703 dma_debug_dent, NULL, &filter_fops);
704 if (!filter_dent)
705 goto out_err;
706
707 return 0;
708
709 out_err:
710 debugfs_remove_recursive(dma_debug_dent);
711
712 return -ENOMEM;
713 }
714
715 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
716 {
717 struct dma_debug_entry *entry;
718 unsigned long flags;
719 int count = 0, i;
720
721 local_irq_save(flags);
722
723 for (i = 0; i < HASH_SIZE; ++i) {
724 spin_lock(&dma_entry_hash[i].lock);
725 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
726 if (entry->dev == dev) {
727 count += 1;
728 *out_entry = entry;
729 }
730 }
731 spin_unlock(&dma_entry_hash[i].lock);
732 }
733
734 local_irq_restore(flags);
735
736 return count;
737 }
738
739 static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
740 {
741 struct device *dev = data;
742 struct dma_debug_entry *uninitialized_var(entry);
743 int count;
744
745 if (global_disable)
746 return 0;
747
748 switch (action) {
749 case BUS_NOTIFY_UNBOUND_DRIVER:
750 count = device_dma_allocations(dev, &entry);
751 if (count == 0)
752 break;
753 err_printk(dev, entry, "DMA-API: device driver has pending "
754 "DMA allocations while released from device "
755 "[count=%d]\n"
756 "One of leaked entries details: "
757 "[device address=0x%016llx] [size=%llu bytes] "
758 "[mapped with %s] [mapped as %s]\n",
759 count, entry->dev_addr, entry->size,
760 dir2name[entry->direction], type2name[entry->type]);
761 break;
762 default:
763 break;
764 }
765
766 return 0;
767 }
768
769 void dma_debug_add_bus(struct bus_type *bus)
770 {
771 struct notifier_block *nb;
772
773 if (global_disable)
774 return;
775
776 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
777 if (nb == NULL) {
778 pr_err("dma_debug_add_bus: out of memory\n");
779 return;
780 }
781
782 nb->notifier_call = dma_debug_device_change;
783
784 bus_register_notifier(bus, nb);
785 }
786
787 /*
788 * Let the architectures decide how many entries should be preallocated.
789 */
790 void dma_debug_init(u32 num_entries)
791 {
792 int i;
793
794 if (global_disable)
795 return;
796
797 for (i = 0; i < HASH_SIZE; ++i) {
798 INIT_LIST_HEAD(&dma_entry_hash[i].list);
799 spin_lock_init(&dma_entry_hash[i].lock);
800 }
801
802 if (dma_debug_fs_init() != 0) {
803 pr_err("DMA-API: error creating debugfs entries - disabling\n");
804 global_disable = true;
805
806 return;
807 }
808
809 if (req_entries)
810 num_entries = req_entries;
811
812 if (prealloc_memory(num_entries) != 0) {
813 pr_err("DMA-API: debugging out of memory error - disabled\n");
814 global_disable = true;
815
816 return;
817 }
818
819 nr_total_entries = num_free_entries;
820
821 pr_info("DMA-API: debugging enabled by kernel config\n");
822 }
823
824 static __init int dma_debug_cmdline(char *str)
825 {
826 if (!str)
827 return -EINVAL;
828
829 if (strncmp(str, "off", 3) == 0) {
830 pr_info("DMA-API: debugging disabled on kernel command line\n");
831 global_disable = true;
832 }
833
834 return 0;
835 }
836
837 static __init int dma_debug_entries_cmdline(char *str)
838 {
839 int res;
840
841 if (!str)
842 return -EINVAL;
843
844 res = get_option(&str, &req_entries);
845
846 if (!res)
847 req_entries = 0;
848
849 return 0;
850 }
851
852 __setup("dma_debug=", dma_debug_cmdline);
853 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
854
855 static void check_unmap(struct dma_debug_entry *ref)
856 {
857 struct dma_debug_entry *entry;
858 struct hash_bucket *bucket;
859 unsigned long flags;
860
861 bucket = get_hash_bucket(ref, &flags);
862 entry = bucket_find_exact(bucket, ref);
863
864 if (!entry) {
865 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
866 err_printk(ref->dev, NULL,
867 "DMA-API: device driver tries "
868 "to free an invalid DMA memory address\n");
869 return;
870 }
871 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
872 "to free DMA memory it has not allocated "
873 "[device address=0x%016llx] [size=%llu bytes]\n",
874 ref->dev_addr, ref->size);
875 goto out;
876 }
877
878 if (ref->size != entry->size) {
879 err_printk(ref->dev, entry, "DMA-API: device driver frees "
880 "DMA memory with different size "
881 "[device address=0x%016llx] [map size=%llu bytes] "
882 "[unmap size=%llu bytes]\n",
883 ref->dev_addr, entry->size, ref->size);
884 }
885
886 if (ref->type != entry->type) {
887 err_printk(ref->dev, entry, "DMA-API: device driver frees "
888 "DMA memory with wrong function "
889 "[device address=0x%016llx] [size=%llu bytes] "
890 "[mapped as %s] [unmapped as %s]\n",
891 ref->dev_addr, ref->size,
892 type2name[entry->type], type2name[ref->type]);
893 } else if ((entry->type == dma_debug_coherent) &&
894 (ref->paddr != entry->paddr)) {
895 err_printk(ref->dev, entry, "DMA-API: device driver frees "
896 "DMA memory with different CPU address "
897 "[device address=0x%016llx] [size=%llu bytes] "
898 "[cpu alloc address=0x%016llx] "
899 "[cpu free address=0x%016llx]",
900 ref->dev_addr, ref->size,
901 (unsigned long long)entry->paddr,
902 (unsigned long long)ref->paddr);
903 }
904
905 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
906 ref->sg_call_ents != entry->sg_call_ents) {
907 err_printk(ref->dev, entry, "DMA-API: device driver frees "
908 "DMA sg list with different entry count "
909 "[map count=%d] [unmap count=%d]\n",
910 entry->sg_call_ents, ref->sg_call_ents);
911 }
912
913 /*
914 * This may be no bug in reality - but most implementations of the
915 * DMA API don't handle this properly, so check for it here
916 */
917 if (ref->direction != entry->direction) {
918 err_printk(ref->dev, entry, "DMA-API: device driver frees "
919 "DMA memory with different direction "
920 "[device address=0x%016llx] [size=%llu bytes] "
921 "[mapped with %s] [unmapped with %s]\n",
922 ref->dev_addr, ref->size,
923 dir2name[entry->direction],
924 dir2name[ref->direction]);
925 }
926
927 if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
928 err_printk(ref->dev, entry,
929 "DMA-API: device driver failed to check map error"
930 "[device address=0x%016llx] [size=%llu bytes] "
931 "[mapped as %s]",
932 ref->dev_addr, ref->size,
933 type2name[entry->type]);
934 }
935
936 hash_bucket_del(entry);
937 dma_entry_free(entry);
938
939 out:
940 put_hash_bucket(bucket, &flags);
941 }
942
943 static void check_for_stack(struct device *dev, void *addr)
944 {
945 if (object_is_on_stack(addr))
946 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
947 "stack [addr=%p]\n", addr);
948 }
949
950 static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
951 {
952 unsigned long a1 = (unsigned long)addr;
953 unsigned long b1 = a1 + len;
954 unsigned long a2 = (unsigned long)start;
955 unsigned long b2 = (unsigned long)end;
956
957 return !(b1 <= a2 || a1 >= b2);
958 }
959
960 static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
961 {
962 if (overlap(addr, len, _text, _etext) ||
963 overlap(addr, len, __start_rodata, __end_rodata))
964 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
965 }
966
967 static void check_sync(struct device *dev,
968 struct dma_debug_entry *ref,
969 bool to_cpu)
970 {
971 struct dma_debug_entry *entry;
972 struct hash_bucket *bucket;
973 unsigned long flags;
974
975 bucket = get_hash_bucket(ref, &flags);
976
977 entry = bucket_find_contain(&bucket, ref, &flags);
978
979 if (!entry) {
980 err_printk(dev, NULL, "DMA-API: device driver tries "
981 "to sync DMA memory it has not allocated "
982 "[device address=0x%016llx] [size=%llu bytes]\n",
983 (unsigned long long)ref->dev_addr, ref->size);
984 goto out;
985 }
986
987 if (ref->size > entry->size) {
988 err_printk(dev, entry, "DMA-API: device driver syncs"
989 " DMA memory outside allocated range "
990 "[device address=0x%016llx] "
991 "[allocation size=%llu bytes] "
992 "[sync offset+size=%llu]\n",
993 entry->dev_addr, entry->size,
994 ref->size);
995 }
996
997 if (entry->direction == DMA_BIDIRECTIONAL)
998 goto out;
999
1000 if (ref->direction != entry->direction) {
1001 err_printk(dev, entry, "DMA-API: device driver syncs "
1002 "DMA memory with different direction "
1003 "[device address=0x%016llx] [size=%llu bytes] "
1004 "[mapped with %s] [synced with %s]\n",
1005 (unsigned long long)ref->dev_addr, entry->size,
1006 dir2name[entry->direction],
1007 dir2name[ref->direction]);
1008 }
1009
1010 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1011 !(ref->direction == DMA_TO_DEVICE))
1012 err_printk(dev, entry, "DMA-API: device driver syncs "
1013 "device read-only DMA memory for cpu "
1014 "[device address=0x%016llx] [size=%llu bytes] "
1015 "[mapped with %s] [synced with %s]\n",
1016 (unsigned long long)ref->dev_addr, entry->size,
1017 dir2name[entry->direction],
1018 dir2name[ref->direction]);
1019
1020 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1021 !(ref->direction == DMA_FROM_DEVICE))
1022 err_printk(dev, entry, "DMA-API: device driver syncs "
1023 "device write-only DMA memory to device "
1024 "[device address=0x%016llx] [size=%llu bytes] "
1025 "[mapped with %s] [synced with %s]\n",
1026 (unsigned long long)ref->dev_addr, entry->size,
1027 dir2name[entry->direction],
1028 dir2name[ref->direction]);
1029
1030 out:
1031 put_hash_bucket(bucket, &flags);
1032 }
1033
1034 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1035 size_t size, int direction, dma_addr_t dma_addr,
1036 bool map_single)
1037 {
1038 struct dma_debug_entry *entry;
1039
1040 if (unlikely(global_disable))
1041 return;
1042
1043 if (dma_mapping_error(dev, dma_addr))
1044 return;
1045
1046 entry = dma_entry_alloc();
1047 if (!entry)
1048 return;
1049
1050 entry->dev = dev;
1051 entry->type = dma_debug_page;
1052 entry->paddr = page_to_phys(page) + offset;
1053 entry->dev_addr = dma_addr;
1054 entry->size = size;
1055 entry->direction = direction;
1056 entry->map_err_type = MAP_ERR_NOT_CHECKED;
1057
1058 if (map_single)
1059 entry->type = dma_debug_single;
1060
1061 if (!PageHighMem(page)) {
1062 void *addr = page_address(page) + offset;
1063
1064 check_for_stack(dev, addr);
1065 check_for_illegal_area(dev, addr, size);
1066 }
1067
1068 add_dma_entry(entry);
1069 }
1070 EXPORT_SYMBOL(debug_dma_map_page);
1071
1072 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1073 {
1074 struct dma_debug_entry ref;
1075 struct dma_debug_entry *entry;
1076 struct hash_bucket *bucket;
1077 unsigned long flags;
1078
1079 if (unlikely(global_disable))
1080 return;
1081
1082 ref.dev = dev;
1083 ref.dev_addr = dma_addr;
1084 bucket = get_hash_bucket(&ref, &flags);
1085 entry = bucket_find_exact(bucket, &ref);
1086
1087 if (!entry)
1088 goto out;
1089
1090 entry->map_err_type = MAP_ERR_CHECKED;
1091 out:
1092 put_hash_bucket(bucket, &flags);
1093 }
1094 EXPORT_SYMBOL(debug_dma_mapping_error);
1095
1096 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1097 size_t size, int direction, bool map_single)
1098 {
1099 struct dma_debug_entry ref = {
1100 .type = dma_debug_page,
1101 .dev = dev,
1102 .dev_addr = addr,
1103 .size = size,
1104 .direction = direction,
1105 };
1106
1107 if (unlikely(global_disable))
1108 return;
1109
1110 if (map_single)
1111 ref.type = dma_debug_single;
1112
1113 check_unmap(&ref);
1114 }
1115 EXPORT_SYMBOL(debug_dma_unmap_page);
1116
1117 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1118 int nents, int mapped_ents, int direction)
1119 {
1120 struct dma_debug_entry *entry;
1121 struct scatterlist *s;
1122 int i;
1123
1124 if (unlikely(global_disable))
1125 return;
1126
1127 for_each_sg(sg, s, mapped_ents, i) {
1128 entry = dma_entry_alloc();
1129 if (!entry)
1130 return;
1131
1132 entry->type = dma_debug_sg;
1133 entry->dev = dev;
1134 entry->paddr = sg_phys(s);
1135 entry->size = sg_dma_len(s);
1136 entry->dev_addr = sg_dma_address(s);
1137 entry->direction = direction;
1138 entry->sg_call_ents = nents;
1139 entry->sg_mapped_ents = mapped_ents;
1140
1141 if (!PageHighMem(sg_page(s))) {
1142 check_for_stack(dev, sg_virt(s));
1143 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1144 }
1145
1146 add_dma_entry(entry);
1147 }
1148 }
1149 EXPORT_SYMBOL(debug_dma_map_sg);
1150
1151 static int get_nr_mapped_entries(struct device *dev,
1152 struct dma_debug_entry *ref)
1153 {
1154 struct dma_debug_entry *entry;
1155 struct hash_bucket *bucket;
1156 unsigned long flags;
1157 int mapped_ents;
1158
1159 bucket = get_hash_bucket(ref, &flags);
1160 entry = bucket_find_exact(bucket, ref);
1161 mapped_ents = 0;
1162
1163 if (entry)
1164 mapped_ents = entry->sg_mapped_ents;
1165 put_hash_bucket(bucket, &flags);
1166
1167 return mapped_ents;
1168 }
1169
1170 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1171 int nelems, int dir)
1172 {
1173 struct scatterlist *s;
1174 int mapped_ents = 0, i;
1175
1176 if (unlikely(global_disable))
1177 return;
1178
1179 for_each_sg(sglist, s, nelems, i) {
1180
1181 struct dma_debug_entry ref = {
1182 .type = dma_debug_sg,
1183 .dev = dev,
1184 .paddr = sg_phys(s),
1185 .dev_addr = sg_dma_address(s),
1186 .size = sg_dma_len(s),
1187 .direction = dir,
1188 .sg_call_ents = nelems,
1189 };
1190
1191 if (mapped_ents && i >= mapped_ents)
1192 break;
1193
1194 if (!i)
1195 mapped_ents = get_nr_mapped_entries(dev, &ref);
1196
1197 check_unmap(&ref);
1198 }
1199 }
1200 EXPORT_SYMBOL(debug_dma_unmap_sg);
1201
1202 void debug_dma_alloc_coherent(struct device *dev, size_t size,
1203 dma_addr_t dma_addr, void *virt)
1204 {
1205 struct dma_debug_entry *entry;
1206
1207 if (unlikely(global_disable))
1208 return;
1209
1210 if (unlikely(virt == NULL))
1211 return;
1212
1213 entry = dma_entry_alloc();
1214 if (!entry)
1215 return;
1216
1217 entry->type = dma_debug_coherent;
1218 entry->dev = dev;
1219 entry->paddr = virt_to_phys(virt);
1220 entry->size = size;
1221 entry->dev_addr = dma_addr;
1222 entry->direction = DMA_BIDIRECTIONAL;
1223
1224 add_dma_entry(entry);
1225 }
1226 EXPORT_SYMBOL(debug_dma_alloc_coherent);
1227
1228 void debug_dma_free_coherent(struct device *dev, size_t size,
1229 void *virt, dma_addr_t addr)
1230 {
1231 struct dma_debug_entry ref = {
1232 .type = dma_debug_coherent,
1233 .dev = dev,
1234 .paddr = virt_to_phys(virt),
1235 .dev_addr = addr,
1236 .size = size,
1237 .direction = DMA_BIDIRECTIONAL,
1238 };
1239
1240 if (unlikely(global_disable))
1241 return;
1242
1243 check_unmap(&ref);
1244 }
1245 EXPORT_SYMBOL(debug_dma_free_coherent);
1246
1247 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1248 size_t size, int direction)
1249 {
1250 struct dma_debug_entry ref;
1251
1252 if (unlikely(global_disable))
1253 return;
1254
1255 ref.type = dma_debug_single;
1256 ref.dev = dev;
1257 ref.dev_addr = dma_handle;
1258 ref.size = size;
1259 ref.direction = direction;
1260 ref.sg_call_ents = 0;
1261
1262 check_sync(dev, &ref, true);
1263 }
1264 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1265
1266 void debug_dma_sync_single_for_device(struct device *dev,
1267 dma_addr_t dma_handle, size_t size,
1268 int direction)
1269 {
1270 struct dma_debug_entry ref;
1271
1272 if (unlikely(global_disable))
1273 return;
1274
1275 ref.type = dma_debug_single;
1276 ref.dev = dev;
1277 ref.dev_addr = dma_handle;
1278 ref.size = size;
1279 ref.direction = direction;
1280 ref.sg_call_ents = 0;
1281
1282 check_sync(dev, &ref, false);
1283 }
1284 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1285
1286 void debug_dma_sync_single_range_for_cpu(struct device *dev,
1287 dma_addr_t dma_handle,
1288 unsigned long offset, size_t size,
1289 int direction)
1290 {
1291 struct dma_debug_entry ref;
1292
1293 if (unlikely(global_disable))
1294 return;
1295
1296 ref.type = dma_debug_single;
1297 ref.dev = dev;
1298 ref.dev_addr = dma_handle;
1299 ref.size = offset + size;
1300 ref.direction = direction;
1301 ref.sg_call_ents = 0;
1302
1303 check_sync(dev, &ref, true);
1304 }
1305 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1306
1307 void debug_dma_sync_single_range_for_device(struct device *dev,
1308 dma_addr_t dma_handle,
1309 unsigned long offset,
1310 size_t size, int direction)
1311 {
1312 struct dma_debug_entry ref;
1313
1314 if (unlikely(global_disable))
1315 return;
1316
1317 ref.type = dma_debug_single;
1318 ref.dev = dev;
1319 ref.dev_addr = dma_handle;
1320 ref.size = offset + size;
1321 ref.direction = direction;
1322 ref.sg_call_ents = 0;
1323
1324 check_sync(dev, &ref, false);
1325 }
1326 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1327
1328 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1329 int nelems, int direction)
1330 {
1331 struct scatterlist *s;
1332 int mapped_ents = 0, i;
1333
1334 if (unlikely(global_disable))
1335 return;
1336
1337 for_each_sg(sg, s, nelems, i) {
1338
1339 struct dma_debug_entry ref = {
1340 .type = dma_debug_sg,
1341 .dev = dev,
1342 .paddr = sg_phys(s),
1343 .dev_addr = sg_dma_address(s),
1344 .size = sg_dma_len(s),
1345 .direction = direction,
1346 .sg_call_ents = nelems,
1347 };
1348
1349 if (!i)
1350 mapped_ents = get_nr_mapped_entries(dev, &ref);
1351
1352 if (i >= mapped_ents)
1353 break;
1354
1355 check_sync(dev, &ref, true);
1356 }
1357 }
1358 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1359
1360 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1361 int nelems, int direction)
1362 {
1363 struct scatterlist *s;
1364 int mapped_ents = 0, i;
1365
1366 if (unlikely(global_disable))
1367 return;
1368
1369 for_each_sg(sg, s, nelems, i) {
1370
1371 struct dma_debug_entry ref = {
1372 .type = dma_debug_sg,
1373 .dev = dev,
1374 .paddr = sg_phys(s),
1375 .dev_addr = sg_dma_address(s),
1376 .size = sg_dma_len(s),
1377 .direction = direction,
1378 .sg_call_ents = nelems,
1379 };
1380 if (!i)
1381 mapped_ents = get_nr_mapped_entries(dev, &ref);
1382
1383 if (i >= mapped_ents)
1384 break;
1385
1386 check_sync(dev, &ref, false);
1387 }
1388 }
1389 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1390
1391 static int __init dma_debug_driver_setup(char *str)
1392 {
1393 int i;
1394
1395 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1396 current_driver_name[i] = *str;
1397 if (*str == 0)
1398 break;
1399 }
1400
1401 if (current_driver_name[0])
1402 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1403 current_driver_name);
1404
1405
1406 return 1;
1407 }
1408 __setup("dma_debug_driver=", dma_debug_driver_setup);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree