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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 | #define DMA_DEBUG_STACKTRACE_ENTRIES 5 |
49 | |
50 | struct dma_debug_entry { |
51 | struct list_head list; |
52 | struct device *dev; |
53 | int type; |
54 | phys_addr_t paddr; |
55 | u64 dev_addr; |
56 | u64 size; |
57 | int direction; |
58 | int sg_call_ents; |
59 | int sg_mapped_ents; |
60 | #ifdef CONFIG_STACKTRACE |
61 | struct stack_trace stacktrace; |
62 | unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES]; |
63 | #endif |
64 | }; |
65 | |
66 | typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *); |
67 | |
68 | struct hash_bucket { |
69 | struct list_head list; |
70 | spinlock_t lock; |
71 | } ____cacheline_aligned_in_smp; |
72 | |
73 | /* Hash list to save the allocated dma addresses */ |
74 | static struct hash_bucket dma_entry_hash[HASH_SIZE]; |
75 | /* List of pre-allocated dma_debug_entry's */ |
76 | static LIST_HEAD(free_entries); |
77 | /* Lock for the list above */ |
78 | static DEFINE_SPINLOCK(free_entries_lock); |
79 | |
80 | /* Global disable flag - will be set in case of an error */ |
81 | static bool global_disable __read_mostly; |
82 | |
83 | /* Global error count */ |
84 | static u32 error_count; |
85 | |
86 | /* Global error show enable*/ |
87 | static u32 show_all_errors __read_mostly; |
88 | /* Number of errors to show */ |
89 | static u32 show_num_errors = 1; |
90 | |
91 | static u32 num_free_entries; |
92 | static u32 min_free_entries; |
93 | static u32 nr_total_entries; |
94 | |
95 | /* number of preallocated entries requested by kernel cmdline */ |
96 | static u32 req_entries; |
97 | |
98 | /* debugfs dentry's for the stuff above */ |
99 | static struct dentry *dma_debug_dent __read_mostly; |
100 | static struct dentry *global_disable_dent __read_mostly; |
101 | static struct dentry *error_count_dent __read_mostly; |
102 | static struct dentry *show_all_errors_dent __read_mostly; |
103 | static struct dentry *show_num_errors_dent __read_mostly; |
104 | static struct dentry *num_free_entries_dent __read_mostly; |
105 | static struct dentry *min_free_entries_dent __read_mostly; |
106 | static struct dentry *filter_dent __read_mostly; |
107 | |
108 | /* per-driver filter related state */ |
109 | |
110 | #define NAME_MAX_LEN 64 |
111 | |
112 | static char current_driver_name[NAME_MAX_LEN] __read_mostly; |
113 | static struct device_driver *current_driver __read_mostly; |
114 | |
115 | static DEFINE_RWLOCK(driver_name_lock); |
116 | |
117 | static const char *type2name[4] = { "single", "page", |
118 | "scather-gather", "coherent" }; |
119 | |
120 | static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE", |
121 | "DMA_FROM_DEVICE", "DMA_NONE" }; |
122 | |
123 | /* little merge helper - remove it after the merge window */ |
124 | #ifndef BUS_NOTIFY_UNBOUND_DRIVER |
125 | #define BUS_NOTIFY_UNBOUND_DRIVER 0x0005 |
126 | #endif |
127 | |
128 | /* |
129 | * The access to some variables in this macro is racy. We can't use atomic_t |
130 | * here because all these variables are exported to debugfs. Some of them even |
131 | * writeable. This is also the reason why a lock won't help much. But anyway, |
132 | * the races are no big deal. Here is why: |
133 | * |
134 | * error_count: the addition is racy, but the worst thing that can happen is |
135 | * that we don't count some errors |
136 | * show_num_errors: the subtraction is racy. Also no big deal because in |
137 | * worst case this will result in one warning more in the |
138 | * system log than the user configured. This variable is |
139 | * writeable via debugfs. |
140 | */ |
141 | static inline void dump_entry_trace(struct dma_debug_entry *entry) |
142 | { |
143 | #ifdef CONFIG_STACKTRACE |
144 | if (entry) { |
145 | pr_warning("Mapped at:\n"); |
146 | print_stack_trace(&entry->stacktrace, 0); |
147 | } |
148 | #endif |
149 | } |
150 | |
151 | static bool driver_filter(struct device *dev) |
152 | { |
153 | struct device_driver *drv; |
154 | unsigned long flags; |
155 | bool ret; |
156 | |
157 | /* driver filter off */ |
158 | if (likely(!current_driver_name[0])) |
159 | return true; |
160 | |
161 | /* driver filter on and initialized */ |
162 | if (current_driver && dev && dev->driver == current_driver) |
163 | return true; |
164 | |
165 | /* driver filter on, but we can't filter on a NULL device... */ |
166 | if (!dev) |
167 | return false; |
168 | |
169 | if (current_driver || !current_driver_name[0]) |
170 | return false; |
171 | |
172 | /* driver filter on but not yet initialized */ |
173 | drv = get_driver(dev->driver); |
174 | if (!drv) |
175 | return false; |
176 | |
177 | /* lock to protect against change of current_driver_name */ |
178 | read_lock_irqsave(&driver_name_lock, flags); |
179 | |
180 | ret = false; |
181 | if (drv->name && |
182 | strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) { |
183 | current_driver = drv; |
184 | ret = true; |
185 | } |
186 | |
187 | read_unlock_irqrestore(&driver_name_lock, flags); |
188 | put_driver(drv); |
189 | |
190 | return ret; |
191 | } |
192 | |
193 | #define err_printk(dev, entry, format, arg...) do { \ |
194 | error_count += 1; \ |
195 | if (driver_filter(dev) && \ |
196 | (show_all_errors || show_num_errors > 0)) { \ |
197 | WARN(1, "%s %s: " format, \ |
198 | dev ? dev_driver_string(dev) : "NULL", \ |
199 | dev ? dev_name(dev) : "NULL", ## arg); \ |
200 | dump_entry_trace(entry); \ |
201 | } \ |
202 | if (!show_all_errors && show_num_errors > 0) \ |
203 | show_num_errors -= 1; \ |
204 | } while (0); |
205 | |
206 | /* |
207 | * Hash related functions |
208 | * |
209 | * Every DMA-API request is saved into a struct dma_debug_entry. To |
210 | * have quick access to these structs they are stored into a hash. |
211 | */ |
212 | static int hash_fn(struct dma_debug_entry *entry) |
213 | { |
214 | /* |
215 | * Hash function is based on the dma address. |
216 | * We use bits 20-27 here as the index into the hash |
217 | */ |
218 | return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK; |
219 | } |
220 | |
221 | /* |
222 | * Request exclusive access to a hash bucket for a given dma_debug_entry. |
223 | */ |
224 | static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry, |
225 | unsigned long *flags) |
226 | { |
227 | int idx = hash_fn(entry); |
228 | unsigned long __flags; |
229 | |
230 | spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags); |
231 | *flags = __flags; |
232 | return &dma_entry_hash[idx]; |
233 | } |
234 | |
235 | /* |
236 | * Give up exclusive access to the hash bucket |
237 | */ |
238 | static void put_hash_bucket(struct hash_bucket *bucket, |
239 | unsigned long *flags) |
240 | { |
241 | unsigned long __flags = *flags; |
242 | |
243 | spin_unlock_irqrestore(&bucket->lock, __flags); |
244 | } |
245 | |
246 | static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b) |
247 | { |
248 | return ((a->dev_addr == b->dev_addr) && |
249 | (a->dev == b->dev)) ? true : false; |
250 | } |
251 | |
252 | static bool containing_match(struct dma_debug_entry *a, |
253 | struct dma_debug_entry *b) |
254 | { |
255 | if (a->dev != b->dev) |
256 | return false; |
257 | |
258 | if ((b->dev_addr <= a->dev_addr) && |
259 | ((b->dev_addr + b->size) >= (a->dev_addr + a->size))) |
260 | return true; |
261 | |
262 | return false; |
263 | } |
264 | |
265 | /* |
266 | * Search a given entry in the hash bucket list |
267 | */ |
268 | static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket, |
269 | struct dma_debug_entry *ref, |
270 | match_fn match) |
271 | { |
272 | struct dma_debug_entry *entry, *ret = NULL; |
273 | int matches = 0, match_lvl, last_lvl = 0; |
274 | |
275 | list_for_each_entry(entry, &bucket->list, list) { |
276 | if (!match(ref, entry)) |
277 | continue; |
278 | |
279 | /* |
280 | * Some drivers map the same physical address multiple |
281 | * times. Without a hardware IOMMU this results in the |
282 | * same device addresses being put into the dma-debug |
283 | * hash multiple times too. This can result in false |
284 | * positives being reported. Therefore we implement a |
285 | * best-fit algorithm here which returns the entry from |
286 | * the hash which fits best to the reference value |
287 | * instead of the first-fit. |
288 | */ |
289 | matches += 1; |
290 | match_lvl = 0; |
291 | entry->size == ref->size ? ++match_lvl : 0; |
292 | entry->type == ref->type ? ++match_lvl : 0; |
293 | entry->direction == ref->direction ? ++match_lvl : 0; |
294 | entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0; |
295 | |
296 | if (match_lvl == 4) { |
297 | /* perfect-fit - return the result */ |
298 | return entry; |
299 | } else if (match_lvl > last_lvl) { |
300 | /* |
301 | * We found an entry that fits better then the |
302 | * previous one |
303 | */ |
304 | last_lvl = match_lvl; |
305 | ret = entry; |
306 | } |
307 | } |
308 | |
309 | /* |
310 | * If we have multiple matches but no perfect-fit, just return |
311 | * NULL. |
312 | */ |
313 | ret = (matches == 1) ? ret : NULL; |
314 | |
315 | return ret; |
316 | } |
317 | |
318 | static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket, |
319 | struct dma_debug_entry *ref) |
320 | { |
321 | return __hash_bucket_find(bucket, ref, exact_match); |
322 | } |
323 | |
324 | static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket, |
325 | struct dma_debug_entry *ref, |
326 | unsigned long *flags) |
327 | { |
328 | |
329 | unsigned int max_range = dma_get_max_seg_size(ref->dev); |
330 | struct dma_debug_entry *entry, index = *ref; |
331 | unsigned int range = 0; |
332 | |
333 | while (range <= max_range) { |
334 | entry = __hash_bucket_find(*bucket, &index, containing_match); |
335 | |
336 | if (entry) |
337 | return entry; |
338 | |
339 | /* |
340 | * Nothing found, go back a hash bucket |
341 | */ |
342 | put_hash_bucket(*bucket, flags); |
343 | range += (1 << HASH_FN_SHIFT); |
344 | index.dev_addr -= (1 << HASH_FN_SHIFT); |
345 | *bucket = get_hash_bucket(&index, flags); |
346 | } |
347 | |
348 | return NULL; |
349 | } |
350 | |
351 | /* |
352 | * Add an entry to a hash bucket |
353 | */ |
354 | static void hash_bucket_add(struct hash_bucket *bucket, |
355 | struct dma_debug_entry *entry) |
356 | { |
357 | list_add_tail(&entry->list, &bucket->list); |
358 | } |
359 | |
360 | /* |
361 | * Remove entry from a hash bucket list |
362 | */ |
363 | static void hash_bucket_del(struct dma_debug_entry *entry) |
364 | { |
365 | list_del(&entry->list); |
366 | } |
367 | |
368 | /* |
369 | * Dump mapping entries for debugging purposes |
370 | */ |
371 | void debug_dma_dump_mappings(struct device *dev) |
372 | { |
373 | int idx; |
374 | |
375 | for (idx = 0; idx < HASH_SIZE; idx++) { |
376 | struct hash_bucket *bucket = &dma_entry_hash[idx]; |
377 | struct dma_debug_entry *entry; |
378 | unsigned long flags; |
379 | |
380 | spin_lock_irqsave(&bucket->lock, flags); |
381 | |
382 | list_for_each_entry(entry, &bucket->list, list) { |
383 | if (!dev || dev == entry->dev) { |
384 | dev_info(entry->dev, |
385 | "%s idx %d P=%Lx D=%Lx L=%Lx %s\n", |
386 | type2name[entry->type], idx, |
387 | (unsigned long long)entry->paddr, |
388 | entry->dev_addr, entry->size, |
389 | dir2name[entry->direction]); |
390 | } |
391 | } |
392 | |
393 | spin_unlock_irqrestore(&bucket->lock, flags); |
394 | } |
395 | } |
396 | EXPORT_SYMBOL(debug_dma_dump_mappings); |
397 | |
398 | /* |
399 | * Wrapper function for adding an entry to the hash. |
400 | * This function takes care of locking itself. |
401 | */ |
402 | static void add_dma_entry(struct dma_debug_entry *entry) |
403 | { |
404 | struct hash_bucket *bucket; |
405 | unsigned long flags; |
406 | |
407 | bucket = get_hash_bucket(entry, &flags); |
408 | hash_bucket_add(bucket, entry); |
409 | put_hash_bucket(bucket, &flags); |
410 | } |
411 | |
412 | static struct dma_debug_entry *__dma_entry_alloc(void) |
413 | { |
414 | struct dma_debug_entry *entry; |
415 | |
416 | entry = list_entry(free_entries.next, struct dma_debug_entry, list); |
417 | list_del(&entry->list); |
418 | memset(entry, 0, sizeof(*entry)); |
419 | |
420 | num_free_entries -= 1; |
421 | if (num_free_entries < min_free_entries) |
422 | min_free_entries = num_free_entries; |
423 | |
424 | return entry; |
425 | } |
426 | |
427 | /* struct dma_entry allocator |
428 | * |
429 | * The next two functions implement the allocator for |
430 | * struct dma_debug_entries. |
431 | */ |
432 | static struct dma_debug_entry *dma_entry_alloc(void) |
433 | { |
434 | struct dma_debug_entry *entry = NULL; |
435 | unsigned long flags; |
436 | |
437 | spin_lock_irqsave(&free_entries_lock, flags); |
438 | |
439 | if (list_empty(&free_entries)) { |
440 | pr_err("DMA-API: debugging out of memory - disabling\n"); |
441 | global_disable = true; |
442 | goto out; |
443 | } |
444 | |
445 | entry = __dma_entry_alloc(); |
446 | |
447 | #ifdef CONFIG_STACKTRACE |
448 | entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES; |
449 | entry->stacktrace.entries = entry->st_entries; |
450 | entry->stacktrace.skip = 2; |
451 | save_stack_trace(&entry->stacktrace); |
452 | #endif |
453 | |
454 | out: |
455 | spin_unlock_irqrestore(&free_entries_lock, flags); |
456 | |
457 | return entry; |
458 | } |
459 | |
460 | static void dma_entry_free(struct dma_debug_entry *entry) |
461 | { |
462 | unsigned long flags; |
463 | |
464 | /* |
465 | * add to beginning of the list - this way the entries are |
466 | * more likely cache hot when they are reallocated. |
467 | */ |
468 | spin_lock_irqsave(&free_entries_lock, flags); |
469 | list_add(&entry->list, &free_entries); |
470 | num_free_entries += 1; |
471 | spin_unlock_irqrestore(&free_entries_lock, flags); |
472 | } |
473 | |
474 | int dma_debug_resize_entries(u32 num_entries) |
475 | { |
476 | int i, delta, ret = 0; |
477 | unsigned long flags; |
478 | struct dma_debug_entry *entry; |
479 | LIST_HEAD(tmp); |
480 | |
481 | spin_lock_irqsave(&free_entries_lock, flags); |
482 | |
483 | if (nr_total_entries < num_entries) { |
484 | delta = num_entries - nr_total_entries; |
485 | |
486 | spin_unlock_irqrestore(&free_entries_lock, flags); |
487 | |
488 | for (i = 0; i < delta; i++) { |
489 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
490 | if (!entry) |
491 | break; |
492 | |
493 | list_add_tail(&entry->list, &tmp); |
494 | } |
495 | |
496 | spin_lock_irqsave(&free_entries_lock, flags); |
497 | |
498 | list_splice(&tmp, &free_entries); |
499 | nr_total_entries += i; |
500 | num_free_entries += i; |
501 | } else { |
502 | delta = nr_total_entries - num_entries; |
503 | |
504 | for (i = 0; i < delta && !list_empty(&free_entries); i++) { |
505 | entry = __dma_entry_alloc(); |
506 | kfree(entry); |
507 | } |
508 | |
509 | nr_total_entries -= i; |
510 | } |
511 | |
512 | if (nr_total_entries != num_entries) |
513 | ret = 1; |
514 | |
515 | spin_unlock_irqrestore(&free_entries_lock, flags); |
516 | |
517 | return ret; |
518 | } |
519 | EXPORT_SYMBOL(dma_debug_resize_entries); |
520 | |
521 | /* |
522 | * DMA-API debugging init code |
523 | * |
524 | * The init code does two things: |
525 | * 1. Initialize core data structures |
526 | * 2. Preallocate a given number of dma_debug_entry structs |
527 | */ |
528 | |
529 | static int prealloc_memory(u32 num_entries) |
530 | { |
531 | struct dma_debug_entry *entry, *next_entry; |
532 | int i; |
533 | |
534 | for (i = 0; i < num_entries; ++i) { |
535 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
536 | if (!entry) |
537 | goto out_err; |
538 | |
539 | list_add_tail(&entry->list, &free_entries); |
540 | } |
541 | |
542 | num_free_entries = num_entries; |
543 | min_free_entries = num_entries; |
544 | |
545 | pr_info("DMA-API: preallocated %d debug entries\n", num_entries); |
546 | |
547 | return 0; |
548 | |
549 | out_err: |
550 | |
551 | list_for_each_entry_safe(entry, next_entry, &free_entries, list) { |
552 | list_del(&entry->list); |
553 | kfree(entry); |
554 | } |
555 | |
556 | return -ENOMEM; |
557 | } |
558 | |
559 | static ssize_t filter_read(struct file *file, char __user *user_buf, |
560 | size_t count, loff_t *ppos) |
561 | { |
562 | char buf[NAME_MAX_LEN + 1]; |
563 | unsigned long flags; |
564 | int len; |
565 | |
566 | if (!current_driver_name[0]) |
567 | return 0; |
568 | |
569 | /* |
570 | * We can't copy to userspace directly because current_driver_name can |
571 | * only be read under the driver_name_lock with irqs disabled. So |
572 | * create a temporary copy first. |
573 | */ |
574 | read_lock_irqsave(&driver_name_lock, flags); |
575 | len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name); |
576 | read_unlock_irqrestore(&driver_name_lock, flags); |
577 | |
578 | return simple_read_from_buffer(user_buf, count, ppos, buf, len); |
579 | } |
580 | |
581 | static ssize_t filter_write(struct file *file, const char __user *userbuf, |
582 | size_t count, loff_t *ppos) |
583 | { |
584 | char buf[NAME_MAX_LEN]; |
585 | unsigned long flags; |
586 | size_t len; |
587 | int i; |
588 | |
589 | /* |
590 | * We can't copy from userspace directly. Access to |
591 | * current_driver_name is protected with a write_lock with irqs |
592 | * disabled. Since copy_from_user can fault and may sleep we |
593 | * need to copy to temporary buffer first |
594 | */ |
595 | len = min(count, (size_t)(NAME_MAX_LEN - 1)); |
596 | if (copy_from_user(buf, userbuf, len)) |
597 | return -EFAULT; |
598 | |
599 | buf[len] = 0; |
600 | |
601 | write_lock_irqsave(&driver_name_lock, flags); |
602 | |
603 | /* |
604 | * Now handle the string we got from userspace very carefully. |
605 | * The rules are: |
606 | * - only use the first token we got |
607 | * - token delimiter is everything looking like a space |
608 | * character (' ', '\n', '\t' ...) |
609 | * |
610 | */ |
611 | if (!isalnum(buf[0])) { |
612 | /* |
613 | * If the first character userspace gave us is not |
614 | * alphanumerical then assume the filter should be |
615 | * switched off. |
616 | */ |
617 | if (current_driver_name[0]) |
618 | pr_info("DMA-API: switching off dma-debug driver filter\n"); |
619 | current_driver_name[0] = 0; |
620 | current_driver = NULL; |
621 | goto out_unlock; |
622 | } |
623 | |
624 | /* |
625 | * Now parse out the first token and use it as the name for the |
626 | * driver to filter for. |
627 | */ |
628 | for (i = 0; i < NAME_MAX_LEN - 1; ++i) { |
629 | current_driver_name[i] = buf[i]; |
630 | if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0) |
631 | break; |
632 | } |
633 | current_driver_name[i] = 0; |
634 | current_driver = NULL; |
635 | |
636 | pr_info("DMA-API: enable driver filter for driver [%s]\n", |
637 | current_driver_name); |
638 | |
639 | out_unlock: |
640 | write_unlock_irqrestore(&driver_name_lock, flags); |
641 | |
642 | return count; |
643 | } |
644 | |
645 | static const struct file_operations filter_fops = { |
646 | .read = filter_read, |
647 | .write = filter_write, |
648 | .llseek = default_llseek, |
649 | }; |
650 | |
651 | static int dma_debug_fs_init(void) |
652 | { |
653 | dma_debug_dent = debugfs_create_dir("dma-api", NULL); |
654 | if (!dma_debug_dent) { |
655 | pr_err("DMA-API: can not create debugfs directory\n"); |
656 | return -ENOMEM; |
657 | } |
658 | |
659 | global_disable_dent = debugfs_create_bool("disabled", 0444, |
660 | dma_debug_dent, |
661 | (u32 *)&global_disable); |
662 | if (!global_disable_dent) |
663 | goto out_err; |
664 | |
665 | error_count_dent = debugfs_create_u32("error_count", 0444, |
666 | dma_debug_dent, &error_count); |
667 | if (!error_count_dent) |
668 | goto out_err; |
669 | |
670 | show_all_errors_dent = debugfs_create_u32("all_errors", 0644, |
671 | dma_debug_dent, |
672 | &show_all_errors); |
673 | if (!show_all_errors_dent) |
674 | goto out_err; |
675 | |
676 | show_num_errors_dent = debugfs_create_u32("num_errors", 0644, |
677 | dma_debug_dent, |
678 | &show_num_errors); |
679 | if (!show_num_errors_dent) |
680 | goto out_err; |
681 | |
682 | num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444, |
683 | dma_debug_dent, |
684 | &num_free_entries); |
685 | if (!num_free_entries_dent) |
686 | goto out_err; |
687 | |
688 | min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444, |
689 | dma_debug_dent, |
690 | &min_free_entries); |
691 | if (!min_free_entries_dent) |
692 | goto out_err; |
693 | |
694 | filter_dent = debugfs_create_file("driver_filter", 0644, |
695 | dma_debug_dent, NULL, &filter_fops); |
696 | if (!filter_dent) |
697 | goto out_err; |
698 | |
699 | return 0; |
700 | |
701 | out_err: |
702 | debugfs_remove_recursive(dma_debug_dent); |
703 | |
704 | return -ENOMEM; |
705 | } |
706 | |
707 | static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry) |
708 | { |
709 | struct dma_debug_entry *entry; |
710 | unsigned long flags; |
711 | int count = 0, i; |
712 | |
713 | local_irq_save(flags); |
714 | |
715 | for (i = 0; i < HASH_SIZE; ++i) { |
716 | spin_lock(&dma_entry_hash[i].lock); |
717 | list_for_each_entry(entry, &dma_entry_hash[i].list, list) { |
718 | if (entry->dev == dev) { |
719 | count += 1; |
720 | *out_entry = entry; |
721 | } |
722 | } |
723 | spin_unlock(&dma_entry_hash[i].lock); |
724 | } |
725 | |
726 | local_irq_restore(flags); |
727 | |
728 | return count; |
729 | } |
730 | |
731 | static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data) |
732 | { |
733 | struct device *dev = data; |
734 | struct dma_debug_entry *uninitialized_var(entry); |
735 | int count; |
736 | |
737 | if (global_disable) |
738 | return 0; |
739 | |
740 | switch (action) { |
741 | case BUS_NOTIFY_UNBOUND_DRIVER: |
742 | count = device_dma_allocations(dev, &entry); |
743 | if (count == 0) |
744 | break; |
745 | err_printk(dev, entry, "DMA-API: device driver has pending " |
746 | "DMA allocations while released from device " |
747 | "[count=%d]\n" |
748 | "One of leaked entries details: " |
749 | "[device address=0x%016llx] [size=%llu bytes] " |
750 | "[mapped with %s] [mapped as %s]\n", |
751 | count, entry->dev_addr, entry->size, |
752 | dir2name[entry->direction], type2name[entry->type]); |
753 | break; |
754 | default: |
755 | break; |
756 | } |
757 | |
758 | return 0; |
759 | } |
760 | |
761 | void dma_debug_add_bus(struct bus_type *bus) |
762 | { |
763 | struct notifier_block *nb; |
764 | |
765 | if (global_disable) |
766 | return; |
767 | |
768 | nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL); |
769 | if (nb == NULL) { |
770 | pr_err("dma_debug_add_bus: out of memory\n"); |
771 | return; |
772 | } |
773 | |
774 | nb->notifier_call = dma_debug_device_change; |
775 | |
776 | bus_register_notifier(bus, nb); |
777 | } |
778 | |
779 | /* |
780 | * Let the architectures decide how many entries should be preallocated. |
781 | */ |
782 | void dma_debug_init(u32 num_entries) |
783 | { |
784 | int i; |
785 | |
786 | if (global_disable) |
787 | return; |
788 | |
789 | for (i = 0; i < HASH_SIZE; ++i) { |
790 | INIT_LIST_HEAD(&dma_entry_hash[i].list); |
791 | spin_lock_init(&dma_entry_hash[i].lock); |
792 | } |
793 | |
794 | if (dma_debug_fs_init() != 0) { |
795 | pr_err("DMA-API: error creating debugfs entries - disabling\n"); |
796 | global_disable = true; |
797 | |
798 | return; |
799 | } |
800 | |
801 | if (req_entries) |
802 | num_entries = req_entries; |
803 | |
804 | if (prealloc_memory(num_entries) != 0) { |
805 | pr_err("DMA-API: debugging out of memory error - disabled\n"); |
806 | global_disable = true; |
807 | |
808 | return; |
809 | } |
810 | |
811 | nr_total_entries = num_free_entries; |
812 | |
813 | pr_info("DMA-API: debugging enabled by kernel config\n"); |
814 | } |
815 | |
816 | static __init int dma_debug_cmdline(char *str) |
817 | { |
818 | if (!str) |
819 | return -EINVAL; |
820 | |
821 | if (strncmp(str, "off", 3) == 0) { |
822 | pr_info("DMA-API: debugging disabled on kernel command line\n"); |
823 | global_disable = true; |
824 | } |
825 | |
826 | return 0; |
827 | } |
828 | |
829 | static __init int dma_debug_entries_cmdline(char *str) |
830 | { |
831 | int res; |
832 | |
833 | if (!str) |
834 | return -EINVAL; |
835 | |
836 | res = get_option(&str, &req_entries); |
837 | |
838 | if (!res) |
839 | req_entries = 0; |
840 | |
841 | return 0; |
842 | } |
843 | |
844 | __setup("dma_debug=", dma_debug_cmdline); |
845 | __setup("dma_debug_entries=", dma_debug_entries_cmdline); |
846 | |
847 | static void check_unmap(struct dma_debug_entry *ref) |
848 | { |
849 | struct dma_debug_entry *entry; |
850 | struct hash_bucket *bucket; |
851 | unsigned long flags; |
852 | |
853 | if (dma_mapping_error(ref->dev, ref->dev_addr)) { |
854 | err_printk(ref->dev, NULL, "DMA-API: device driver tries " |
855 | "to free an invalid DMA memory address\n"); |
856 | return; |
857 | } |
858 | |
859 | bucket = get_hash_bucket(ref, &flags); |
860 | entry = bucket_find_exact(bucket, ref); |
861 | |
862 | if (!entry) { |
863 | err_printk(ref->dev, NULL, "DMA-API: device driver tries " |
864 | "to free DMA memory it has not allocated " |
865 | "[device address=0x%016llx] [size=%llu bytes]\n", |
866 | ref->dev_addr, ref->size); |
867 | goto out; |
868 | } |
869 | |
870 | if (ref->size != entry->size) { |
871 | err_printk(ref->dev, entry, "DMA-API: device driver frees " |
872 | "DMA memory with different size " |
873 | "[device address=0x%016llx] [map size=%llu bytes] " |
874 | "[unmap size=%llu bytes]\n", |
875 | ref->dev_addr, entry->size, ref->size); |
876 | } |
877 | |
878 | if (ref->type != entry->type) { |
879 | err_printk(ref->dev, entry, "DMA-API: device driver frees " |
880 | "DMA memory with wrong function " |
881 | "[device address=0x%016llx] [size=%llu bytes] " |
882 | "[mapped as %s] [unmapped as %s]\n", |
883 | ref->dev_addr, ref->size, |
884 | type2name[entry->type], type2name[ref->type]); |
885 | } else if ((entry->type == dma_debug_coherent) && |
886 | (ref->paddr != entry->paddr)) { |
887 | err_printk(ref->dev, entry, "DMA-API: device driver frees " |
888 | "DMA memory with different CPU address " |
889 | "[device address=0x%016llx] [size=%llu bytes] " |
890 | "[cpu alloc address=0x%016llx] " |
891 | "[cpu free address=0x%016llx]", |
892 | ref->dev_addr, ref->size, |
893 | (unsigned long long)entry->paddr, |
894 | (unsigned long long)ref->paddr); |
895 | } |
896 | |
897 | if (ref->sg_call_ents && ref->type == dma_debug_sg && |
898 | ref->sg_call_ents != entry->sg_call_ents) { |
899 | err_printk(ref->dev, entry, "DMA-API: device driver frees " |
900 | "DMA sg list with different entry count " |
901 | "[map count=%d] [unmap count=%d]\n", |
902 | entry->sg_call_ents, ref->sg_call_ents); |
903 | } |
904 | |
905 | /* |
906 | * This may be no bug in reality - but most implementations of the |
907 | * DMA API don't handle this properly, so check for it here |
908 | */ |
909 | if (ref->direction != entry->direction) { |
910 | err_printk(ref->dev, entry, "DMA-API: device driver frees " |
911 | "DMA memory with different direction " |
912 | "[device address=0x%016llx] [size=%llu bytes] " |
913 | "[mapped with %s] [unmapped with %s]\n", |
914 | ref->dev_addr, ref->size, |
915 | dir2name[entry->direction], |
916 | dir2name[ref->direction]); |
917 | } |
918 | |
919 | hash_bucket_del(entry); |
920 | dma_entry_free(entry); |
921 | |
922 | out: |
923 | put_hash_bucket(bucket, &flags); |
924 | } |
925 | |
926 | static void check_for_stack(struct device *dev, void *addr) |
927 | { |
928 | if (object_is_on_stack(addr)) |
929 | err_printk(dev, NULL, "DMA-API: device driver maps memory from" |
930 | "stack [addr=%p]\n", addr); |
931 | } |
932 | |
933 | static inline bool overlap(void *addr, unsigned long len, void *start, void *end) |
934 | { |
935 | unsigned long a1 = (unsigned long)addr; |
936 | unsigned long b1 = a1 + len; |
937 | unsigned long a2 = (unsigned long)start; |
938 | unsigned long b2 = (unsigned long)end; |
939 | |
940 | return !(b1 <= a2 || a1 >= b2); |
941 | } |
942 | |
943 | static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len) |
944 | { |
945 | if (overlap(addr, len, _text, _etext) || |
946 | overlap(addr, len, __start_rodata, __end_rodata)) |
947 | err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len); |
948 | } |
949 | |
950 | static void check_sync(struct device *dev, |
951 | struct dma_debug_entry *ref, |
952 | bool to_cpu) |
953 | { |
954 | struct dma_debug_entry *entry; |
955 | struct hash_bucket *bucket; |
956 | unsigned long flags; |
957 | |
958 | bucket = get_hash_bucket(ref, &flags); |
959 | |
960 | entry = bucket_find_contain(&bucket, ref, &flags); |
961 | |
962 | if (!entry) { |
963 | err_printk(dev, NULL, "DMA-API: device driver tries " |
964 | "to sync DMA memory it has not allocated " |
965 | "[device address=0x%016llx] [size=%llu bytes]\n", |
966 | (unsigned long long)ref->dev_addr, ref->size); |
967 | goto out; |
968 | } |
969 | |
970 | if (ref->size > entry->size) { |
971 | err_printk(dev, entry, "DMA-API: device driver syncs" |
972 | " DMA memory outside allocated range " |
973 | "[device address=0x%016llx] " |
974 | "[allocation size=%llu bytes] " |
975 | "[sync offset+size=%llu]\n", |
976 | entry->dev_addr, entry->size, |
977 | ref->size); |
978 | } |
979 | |
980 | if (entry->direction == DMA_BIDIRECTIONAL) |
981 | goto out; |
982 | |
983 | if (ref->direction != entry->direction) { |
984 | err_printk(dev, entry, "DMA-API: device driver syncs " |
985 | "DMA memory with different direction " |
986 | "[device address=0x%016llx] [size=%llu bytes] " |
987 | "[mapped with %s] [synced with %s]\n", |
988 | (unsigned long long)ref->dev_addr, entry->size, |
989 | dir2name[entry->direction], |
990 | dir2name[ref->direction]); |
991 | } |
992 | |
993 | if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) && |
994 | !(ref->direction == DMA_TO_DEVICE)) |
995 | err_printk(dev, entry, "DMA-API: device driver syncs " |
996 | "device read-only DMA memory for cpu " |
997 | "[device address=0x%016llx] [size=%llu bytes] " |
998 | "[mapped with %s] [synced with %s]\n", |
999 | (unsigned long long)ref->dev_addr, entry->size, |
1000 | dir2name[entry->direction], |
1001 | dir2name[ref->direction]); |
1002 | |
1003 | if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) && |
1004 | !(ref->direction == DMA_FROM_DEVICE)) |
1005 | err_printk(dev, entry, "DMA-API: device driver syncs " |
1006 | "device write-only DMA memory to device " |
1007 | "[device address=0x%016llx] [size=%llu bytes] " |
1008 | "[mapped with %s] [synced with %s]\n", |
1009 | (unsigned long long)ref->dev_addr, entry->size, |
1010 | dir2name[entry->direction], |
1011 | dir2name[ref->direction]); |
1012 | |
1013 | out: |
1014 | put_hash_bucket(bucket, &flags); |
1015 | } |
1016 | |
1017 | void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, |
1018 | size_t size, int direction, dma_addr_t dma_addr, |
1019 | bool map_single) |
1020 | { |
1021 | struct dma_debug_entry *entry; |
1022 | |
1023 | if (unlikely(global_disable)) |
1024 | return; |
1025 | |
1026 | if (unlikely(dma_mapping_error(dev, dma_addr))) |
1027 | return; |
1028 | |
1029 | entry = dma_entry_alloc(); |
1030 | if (!entry) |
1031 | return; |
1032 | |
1033 | entry->dev = dev; |
1034 | entry->type = dma_debug_page; |
1035 | entry->paddr = page_to_phys(page) + offset; |
1036 | entry->dev_addr = dma_addr; |
1037 | entry->size = size; |
1038 | entry->direction = direction; |
1039 | |
1040 | if (map_single) |
1041 | entry->type = dma_debug_single; |
1042 | |
1043 | if (!PageHighMem(page)) { |
1044 | void *addr = page_address(page) + offset; |
1045 | |
1046 | check_for_stack(dev, addr); |
1047 | check_for_illegal_area(dev, addr, size); |
1048 | } |
1049 | |
1050 | add_dma_entry(entry); |
1051 | } |
1052 | EXPORT_SYMBOL(debug_dma_map_page); |
1053 | |
1054 | void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, |
1055 | size_t size, int direction, bool map_single) |
1056 | { |
1057 | struct dma_debug_entry ref = { |
1058 | .type = dma_debug_page, |
1059 | .dev = dev, |
1060 | .dev_addr = addr, |
1061 | .size = size, |
1062 | .direction = direction, |
1063 | }; |
1064 | |
1065 | if (unlikely(global_disable)) |
1066 | return; |
1067 | |
1068 | if (map_single) |
1069 | ref.type = dma_debug_single; |
1070 | |
1071 | check_unmap(&ref); |
1072 | } |
1073 | EXPORT_SYMBOL(debug_dma_unmap_page); |
1074 | |
1075 | void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, |
1076 | int nents, int mapped_ents, int direction) |
1077 | { |
1078 | struct dma_debug_entry *entry; |
1079 | struct scatterlist *s; |
1080 | int i; |
1081 | |
1082 | if (unlikely(global_disable)) |
1083 | return; |
1084 | |
1085 | for_each_sg(sg, s, mapped_ents, i) { |
1086 | entry = dma_entry_alloc(); |
1087 | if (!entry) |
1088 | return; |
1089 | |
1090 | entry->type = dma_debug_sg; |
1091 | entry->dev = dev; |
1092 | entry->paddr = sg_phys(s); |
1093 | entry->size = sg_dma_len(s); |
1094 | entry->dev_addr = sg_dma_address(s); |
1095 | entry->direction = direction; |
1096 | entry->sg_call_ents = nents; |
1097 | entry->sg_mapped_ents = mapped_ents; |
1098 | |
1099 | if (!PageHighMem(sg_page(s))) { |
1100 | check_for_stack(dev, sg_virt(s)); |
1101 | check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s)); |
1102 | } |
1103 | |
1104 | add_dma_entry(entry); |
1105 | } |
1106 | } |
1107 | EXPORT_SYMBOL(debug_dma_map_sg); |
1108 | |
1109 | static int get_nr_mapped_entries(struct device *dev, |
1110 | struct dma_debug_entry *ref) |
1111 | { |
1112 | struct dma_debug_entry *entry; |
1113 | struct hash_bucket *bucket; |
1114 | unsigned long flags; |
1115 | int mapped_ents; |
1116 | |
1117 | bucket = get_hash_bucket(ref, &flags); |
1118 | entry = bucket_find_exact(bucket, ref); |
1119 | mapped_ents = 0; |
1120 | |
1121 | if (entry) |
1122 | mapped_ents = entry->sg_mapped_ents; |
1123 | put_hash_bucket(bucket, &flags); |
1124 | |
1125 | return mapped_ents; |
1126 | } |
1127 | |
1128 | void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, |
1129 | int nelems, int dir) |
1130 | { |
1131 | struct scatterlist *s; |
1132 | int mapped_ents = 0, i; |
1133 | |
1134 | if (unlikely(global_disable)) |
1135 | return; |
1136 | |
1137 | for_each_sg(sglist, s, nelems, i) { |
1138 | |
1139 | struct dma_debug_entry ref = { |
1140 | .type = dma_debug_sg, |
1141 | .dev = dev, |
1142 | .paddr = sg_phys(s), |
1143 | .dev_addr = sg_dma_address(s), |
1144 | .size = sg_dma_len(s), |
1145 | .direction = dir, |
1146 | .sg_call_ents = nelems, |
1147 | }; |
1148 | |
1149 | if (mapped_ents && i >= mapped_ents) |
1150 | break; |
1151 | |
1152 | if (!i) |
1153 | mapped_ents = get_nr_mapped_entries(dev, &ref); |
1154 | |
1155 | check_unmap(&ref); |
1156 | } |
1157 | } |
1158 | EXPORT_SYMBOL(debug_dma_unmap_sg); |
1159 | |
1160 | void debug_dma_alloc_coherent(struct device *dev, size_t size, |
1161 | dma_addr_t dma_addr, void *virt) |
1162 | { |
1163 | struct dma_debug_entry *entry; |
1164 | |
1165 | if (unlikely(global_disable)) |
1166 | return; |
1167 | |
1168 | if (unlikely(virt == NULL)) |
1169 | return; |
1170 | |
1171 | entry = dma_entry_alloc(); |
1172 | if (!entry) |
1173 | return; |
1174 | |
1175 | entry->type = dma_debug_coherent; |
1176 | entry->dev = dev; |
1177 | entry->paddr = virt_to_phys(virt); |
1178 | entry->size = size; |
1179 | entry->dev_addr = dma_addr; |
1180 | entry->direction = DMA_BIDIRECTIONAL; |
1181 | |
1182 | add_dma_entry(entry); |
1183 | } |
1184 | EXPORT_SYMBOL(debug_dma_alloc_coherent); |
1185 | |
1186 | void debug_dma_free_coherent(struct device *dev, size_t size, |
1187 | void *virt, dma_addr_t addr) |
1188 | { |
1189 | struct dma_debug_entry ref = { |
1190 | .type = dma_debug_coherent, |
1191 | .dev = dev, |
1192 | .paddr = virt_to_phys(virt), |
1193 | .dev_addr = addr, |
1194 | .size = size, |
1195 | .direction = DMA_BIDIRECTIONAL, |
1196 | }; |
1197 | |
1198 | if (unlikely(global_disable)) |
1199 | return; |
1200 | |
1201 | check_unmap(&ref); |
1202 | } |
1203 | EXPORT_SYMBOL(debug_dma_free_coherent); |
1204 | |
1205 | void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, |
1206 | size_t size, int direction) |
1207 | { |
1208 | struct dma_debug_entry ref; |
1209 | |
1210 | if (unlikely(global_disable)) |
1211 | return; |
1212 | |
1213 | ref.type = dma_debug_single; |
1214 | ref.dev = dev; |
1215 | ref.dev_addr = dma_handle; |
1216 | ref.size = size; |
1217 | ref.direction = direction; |
1218 | ref.sg_call_ents = 0; |
1219 | |
1220 | check_sync(dev, &ref, true); |
1221 | } |
1222 | EXPORT_SYMBOL(debug_dma_sync_single_for_cpu); |
1223 | |
1224 | void debug_dma_sync_single_for_device(struct device *dev, |
1225 | dma_addr_t dma_handle, size_t size, |
1226 | int direction) |
1227 | { |
1228 | struct dma_debug_entry ref; |
1229 | |
1230 | if (unlikely(global_disable)) |
1231 | return; |
1232 | |
1233 | ref.type = dma_debug_single; |
1234 | ref.dev = dev; |
1235 | ref.dev_addr = dma_handle; |
1236 | ref.size = size; |
1237 | ref.direction = direction; |
1238 | ref.sg_call_ents = 0; |
1239 | |
1240 | check_sync(dev, &ref, false); |
1241 | } |
1242 | EXPORT_SYMBOL(debug_dma_sync_single_for_device); |
1243 | |
1244 | void debug_dma_sync_single_range_for_cpu(struct device *dev, |
1245 | dma_addr_t dma_handle, |
1246 | unsigned long offset, size_t size, |
1247 | int direction) |
1248 | { |
1249 | struct dma_debug_entry ref; |
1250 | |
1251 | if (unlikely(global_disable)) |
1252 | return; |
1253 | |
1254 | ref.type = dma_debug_single; |
1255 | ref.dev = dev; |
1256 | ref.dev_addr = dma_handle; |
1257 | ref.size = offset + size; |
1258 | ref.direction = direction; |
1259 | ref.sg_call_ents = 0; |
1260 | |
1261 | check_sync(dev, &ref, true); |
1262 | } |
1263 | EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu); |
1264 | |
1265 | void debug_dma_sync_single_range_for_device(struct device *dev, |
1266 | dma_addr_t dma_handle, |
1267 | unsigned long offset, |
1268 | size_t size, 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 = offset + 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_range_for_device); |
1285 | |
1286 | void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, |
1287 | int nelems, int direction) |
1288 | { |
1289 | struct scatterlist *s; |
1290 | int mapped_ents = 0, i; |
1291 | |
1292 | if (unlikely(global_disable)) |
1293 | return; |
1294 | |
1295 | for_each_sg(sg, s, nelems, i) { |
1296 | |
1297 | struct dma_debug_entry ref = { |
1298 | .type = dma_debug_sg, |
1299 | .dev = dev, |
1300 | .paddr = sg_phys(s), |
1301 | .dev_addr = sg_dma_address(s), |
1302 | .size = sg_dma_len(s), |
1303 | .direction = direction, |
1304 | .sg_call_ents = nelems, |
1305 | }; |
1306 | |
1307 | if (!i) |
1308 | mapped_ents = get_nr_mapped_entries(dev, &ref); |
1309 | |
1310 | if (i >= mapped_ents) |
1311 | break; |
1312 | |
1313 | check_sync(dev, &ref, true); |
1314 | } |
1315 | } |
1316 | EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu); |
1317 | |
1318 | void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, |
1319 | int nelems, int direction) |
1320 | { |
1321 | struct scatterlist *s; |
1322 | int mapped_ents = 0, i; |
1323 | |
1324 | if (unlikely(global_disable)) |
1325 | return; |
1326 | |
1327 | for_each_sg(sg, s, nelems, i) { |
1328 | |
1329 | struct dma_debug_entry ref = { |
1330 | .type = dma_debug_sg, |
1331 | .dev = dev, |
1332 | .paddr = sg_phys(s), |
1333 | .dev_addr = sg_dma_address(s), |
1334 | .size = sg_dma_len(s), |
1335 | .direction = direction, |
1336 | .sg_call_ents = nelems, |
1337 | }; |
1338 | if (!i) |
1339 | mapped_ents = get_nr_mapped_entries(dev, &ref); |
1340 | |
1341 | if (i >= mapped_ents) |
1342 | break; |
1343 | |
1344 | check_sync(dev, &ref, false); |
1345 | } |
1346 | } |
1347 | EXPORT_SYMBOL(debug_dma_sync_sg_for_device); |
1348 | |
1349 | static int __init dma_debug_driver_setup(char *str) |
1350 | { |
1351 | int i; |
1352 | |
1353 | for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) { |
1354 | current_driver_name[i] = *str; |
1355 | if (*str == 0) |
1356 | break; |
1357 | } |
1358 | |
1359 | if (current_driver_name[0]) |
1360 | pr_info("DMA-API: enable driver filter for driver [%s]\n", |
1361 | current_driver_name); |
1362 | |
1363 | |
1364 | return 1; |
1365 | } |
1366 | __setup("dma_debug_driver=", dma_debug_driver_setup); |
1367 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
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v3.9