cgroup, cpuset: remove cgroup_subsys->post_clone()
[linux-2.6/libata-dev.git] / lib / dma-debug.c
blobd84beb994f36f1c0b6d7e82fa02fc558a13f88c9
1 /*
2 * Copyright (C) 2008 Advanced Micro Devices, Inc.
4 * Author: Joerg Roedel <joerg.roedel@amd.com>
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.
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.
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
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>
35 #include <asm/sections.h>
37 #define HASH_SIZE 1024ULL
38 #define HASH_FN_SHIFT 13
39 #define HASH_FN_MASK (HASH_SIZE - 1)
41 enum {
42 dma_debug_single,
43 dma_debug_page,
44 dma_debug_sg,
45 dma_debug_coherent,
48 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
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
66 typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
68 struct hash_bucket {
69 struct list_head list;
70 spinlock_t lock;
71 } ____cacheline_aligned_in_smp;
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);
80 /* Global disable flag - will be set in case of an error */
81 static u32 global_disable __read_mostly;
83 /* Global error count */
84 static u32 error_count;
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;
91 static u32 num_free_entries;
92 static u32 min_free_entries;
93 static u32 nr_total_entries;
95 /* number of preallocated entries requested by kernel cmdline */
96 static u32 req_entries;
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;
108 /* per-driver filter related state */
110 #define NAME_MAX_LEN 64
112 static char current_driver_name[NAME_MAX_LEN] __read_mostly;
113 static struct device_driver *current_driver __read_mostly;
115 static DEFINE_RWLOCK(driver_name_lock);
117 static const char *type2name[4] = { "single", "page",
118 "scather-gather", "coherent" };
120 static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
121 "DMA_FROM_DEVICE", "DMA_NONE" };
124 * The access to some variables in this macro is racy. We can't use atomic_t
125 * here because all these variables are exported to debugfs. Some of them even
126 * writeable. This is also the reason why a lock won't help much. But anyway,
127 * the races are no big deal. Here is why:
129 * error_count: the addition is racy, but the worst thing that can happen is
130 * that we don't count some errors
131 * show_num_errors: the subtraction is racy. Also no big deal because in
132 * worst case this will result in one warning more in the
133 * system log than the user configured. This variable is
134 * writeable via debugfs.
136 static inline void dump_entry_trace(struct dma_debug_entry *entry)
138 #ifdef CONFIG_STACKTRACE
139 if (entry) {
140 pr_warning("Mapped at:\n");
141 print_stack_trace(&entry->stacktrace, 0);
143 #endif
146 static bool driver_filter(struct device *dev)
148 struct device_driver *drv;
149 unsigned long flags;
150 bool ret;
152 /* driver filter off */
153 if (likely(!current_driver_name[0]))
154 return true;
156 /* driver filter on and initialized */
157 if (current_driver && dev && dev->driver == current_driver)
158 return true;
160 /* driver filter on, but we can't filter on a NULL device... */
161 if (!dev)
162 return false;
164 if (current_driver || !current_driver_name[0])
165 return false;
167 /* driver filter on but not yet initialized */
168 drv = dev->driver;
169 if (!drv)
170 return false;
172 /* lock to protect against change of current_driver_name */
173 read_lock_irqsave(&driver_name_lock, flags);
175 ret = false;
176 if (drv->name &&
177 strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
178 current_driver = drv;
179 ret = true;
182 read_unlock_irqrestore(&driver_name_lock, flags);
184 return ret;
187 #define err_printk(dev, entry, format, arg...) do { \
188 error_count += 1; \
189 if (driver_filter(dev) && \
190 (show_all_errors || show_num_errors > 0)) { \
191 WARN(1, "%s %s: " format, \
192 dev ? dev_driver_string(dev) : "NULL", \
193 dev ? dev_name(dev) : "NULL", ## arg); \
194 dump_entry_trace(entry); \
196 if (!show_all_errors && show_num_errors > 0) \
197 show_num_errors -= 1; \
198 } while (0);
201 * Hash related functions
203 * Every DMA-API request is saved into a struct dma_debug_entry. To
204 * have quick access to these structs they are stored into a hash.
206 static int hash_fn(struct dma_debug_entry *entry)
209 * Hash function is based on the dma address.
210 * We use bits 20-27 here as the index into the hash
212 return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
216 * Request exclusive access to a hash bucket for a given dma_debug_entry.
218 static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
219 unsigned long *flags)
221 int idx = hash_fn(entry);
222 unsigned long __flags;
224 spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
225 *flags = __flags;
226 return &dma_entry_hash[idx];
230 * Give up exclusive access to the hash bucket
232 static void put_hash_bucket(struct hash_bucket *bucket,
233 unsigned long *flags)
235 unsigned long __flags = *flags;
237 spin_unlock_irqrestore(&bucket->lock, __flags);
240 static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
242 return ((a->dev_addr == b->dev_addr) &&
243 (a->dev == b->dev)) ? true : false;
246 static bool containing_match(struct dma_debug_entry *a,
247 struct dma_debug_entry *b)
249 if (a->dev != b->dev)
250 return false;
252 if ((b->dev_addr <= a->dev_addr) &&
253 ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
254 return true;
256 return false;
260 * Search a given entry in the hash bucket list
262 static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
263 struct dma_debug_entry *ref,
264 match_fn match)
266 struct dma_debug_entry *entry, *ret = NULL;
267 int matches = 0, match_lvl, last_lvl = -1;
269 list_for_each_entry(entry, &bucket->list, list) {
270 if (!match(ref, entry))
271 continue;
274 * Some drivers map the same physical address multiple
275 * times. Without a hardware IOMMU this results in the
276 * same device addresses being put into the dma-debug
277 * hash multiple times too. This can result in false
278 * positives being reported. Therefore we implement a
279 * best-fit algorithm here which returns the entry from
280 * the hash which fits best to the reference value
281 * instead of the first-fit.
283 matches += 1;
284 match_lvl = 0;
285 entry->size == ref->size ? ++match_lvl : 0;
286 entry->type == ref->type ? ++match_lvl : 0;
287 entry->direction == ref->direction ? ++match_lvl : 0;
288 entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
290 if (match_lvl == 4) {
291 /* perfect-fit - return the result */
292 return entry;
293 } else if (match_lvl > last_lvl) {
295 * We found an entry that fits better then the
296 * previous one or it is the 1st match.
298 last_lvl = match_lvl;
299 ret = entry;
304 * If we have multiple matches but no perfect-fit, just return
305 * NULL.
307 ret = (matches == 1) ? ret : NULL;
309 return ret;
312 static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
313 struct dma_debug_entry *ref)
315 return __hash_bucket_find(bucket, ref, exact_match);
318 static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
319 struct dma_debug_entry *ref,
320 unsigned long *flags)
323 unsigned int max_range = dma_get_max_seg_size(ref->dev);
324 struct dma_debug_entry *entry, index = *ref;
325 unsigned int range = 0;
327 while (range <= max_range) {
328 entry = __hash_bucket_find(*bucket, &index, containing_match);
330 if (entry)
331 return entry;
334 * Nothing found, go back a hash bucket
336 put_hash_bucket(*bucket, flags);
337 range += (1 << HASH_FN_SHIFT);
338 index.dev_addr -= (1 << HASH_FN_SHIFT);
339 *bucket = get_hash_bucket(&index, flags);
342 return NULL;
346 * Add an entry to a hash bucket
348 static void hash_bucket_add(struct hash_bucket *bucket,
349 struct dma_debug_entry *entry)
351 list_add_tail(&entry->list, &bucket->list);
355 * Remove entry from a hash bucket list
357 static void hash_bucket_del(struct dma_debug_entry *entry)
359 list_del(&entry->list);
363 * Dump mapping entries for debugging purposes
365 void debug_dma_dump_mappings(struct device *dev)
367 int idx;
369 for (idx = 0; idx < HASH_SIZE; idx++) {
370 struct hash_bucket *bucket = &dma_entry_hash[idx];
371 struct dma_debug_entry *entry;
372 unsigned long flags;
374 spin_lock_irqsave(&bucket->lock, flags);
376 list_for_each_entry(entry, &bucket->list, list) {
377 if (!dev || dev == entry->dev) {
378 dev_info(entry->dev,
379 "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
380 type2name[entry->type], idx,
381 (unsigned long long)entry->paddr,
382 entry->dev_addr, entry->size,
383 dir2name[entry->direction]);
387 spin_unlock_irqrestore(&bucket->lock, flags);
390 EXPORT_SYMBOL(debug_dma_dump_mappings);
393 * Wrapper function for adding an entry to the hash.
394 * This function takes care of locking itself.
396 static void add_dma_entry(struct dma_debug_entry *entry)
398 struct hash_bucket *bucket;
399 unsigned long flags;
401 bucket = get_hash_bucket(entry, &flags);
402 hash_bucket_add(bucket, entry);
403 put_hash_bucket(bucket, &flags);
406 static struct dma_debug_entry *__dma_entry_alloc(void)
408 struct dma_debug_entry *entry;
410 entry = list_entry(free_entries.next, struct dma_debug_entry, list);
411 list_del(&entry->list);
412 memset(entry, 0, sizeof(*entry));
414 num_free_entries -= 1;
415 if (num_free_entries < min_free_entries)
416 min_free_entries = num_free_entries;
418 return entry;
421 /* struct dma_entry allocator
423 * The next two functions implement the allocator for
424 * struct dma_debug_entries.
426 static struct dma_debug_entry *dma_entry_alloc(void)
428 struct dma_debug_entry *entry;
429 unsigned long flags;
431 spin_lock_irqsave(&free_entries_lock, flags);
433 if (list_empty(&free_entries)) {
434 pr_err("DMA-API: debugging out of memory - disabling\n");
435 global_disable = true;
436 spin_unlock_irqrestore(&free_entries_lock, flags);
437 return NULL;
440 entry = __dma_entry_alloc();
442 spin_unlock_irqrestore(&free_entries_lock, flags);
444 #ifdef CONFIG_STACKTRACE
445 entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
446 entry->stacktrace.entries = entry->st_entries;
447 entry->stacktrace.skip = 2;
448 save_stack_trace(&entry->stacktrace);
449 #endif
451 return entry;
454 static void dma_entry_free(struct dma_debug_entry *entry)
456 unsigned long flags;
459 * add to beginning of the list - this way the entries are
460 * more likely cache hot when they are reallocated.
462 spin_lock_irqsave(&free_entries_lock, flags);
463 list_add(&entry->list, &free_entries);
464 num_free_entries += 1;
465 spin_unlock_irqrestore(&free_entries_lock, flags);
468 int dma_debug_resize_entries(u32 num_entries)
470 int i, delta, ret = 0;
471 unsigned long flags;
472 struct dma_debug_entry *entry;
473 LIST_HEAD(tmp);
475 spin_lock_irqsave(&free_entries_lock, flags);
477 if (nr_total_entries < num_entries) {
478 delta = num_entries - nr_total_entries;
480 spin_unlock_irqrestore(&free_entries_lock, flags);
482 for (i = 0; i < delta; i++) {
483 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
484 if (!entry)
485 break;
487 list_add_tail(&entry->list, &tmp);
490 spin_lock_irqsave(&free_entries_lock, flags);
492 list_splice(&tmp, &free_entries);
493 nr_total_entries += i;
494 num_free_entries += i;
495 } else {
496 delta = nr_total_entries - num_entries;
498 for (i = 0; i < delta && !list_empty(&free_entries); i++) {
499 entry = __dma_entry_alloc();
500 kfree(entry);
503 nr_total_entries -= i;
506 if (nr_total_entries != num_entries)
507 ret = 1;
509 spin_unlock_irqrestore(&free_entries_lock, flags);
511 return ret;
513 EXPORT_SYMBOL(dma_debug_resize_entries);
516 * DMA-API debugging init code
518 * The init code does two things:
519 * 1. Initialize core data structures
520 * 2. Preallocate a given number of dma_debug_entry structs
523 static int prealloc_memory(u32 num_entries)
525 struct dma_debug_entry *entry, *next_entry;
526 int i;
528 for (i = 0; i < num_entries; ++i) {
529 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
530 if (!entry)
531 goto out_err;
533 list_add_tail(&entry->list, &free_entries);
536 num_free_entries = num_entries;
537 min_free_entries = num_entries;
539 pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
541 return 0;
543 out_err:
545 list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
546 list_del(&entry->list);
547 kfree(entry);
550 return -ENOMEM;
553 static ssize_t filter_read(struct file *file, char __user *user_buf,
554 size_t count, loff_t *ppos)
556 char buf[NAME_MAX_LEN + 1];
557 unsigned long flags;
558 int len;
560 if (!current_driver_name[0])
561 return 0;
564 * We can't copy to userspace directly because current_driver_name can
565 * only be read under the driver_name_lock with irqs disabled. So
566 * create a temporary copy first.
568 read_lock_irqsave(&driver_name_lock, flags);
569 len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
570 read_unlock_irqrestore(&driver_name_lock, flags);
572 return simple_read_from_buffer(user_buf, count, ppos, buf, len);
575 static ssize_t filter_write(struct file *file, const char __user *userbuf,
576 size_t count, loff_t *ppos)
578 char buf[NAME_MAX_LEN];
579 unsigned long flags;
580 size_t len;
581 int i;
584 * We can't copy from userspace directly. Access to
585 * current_driver_name is protected with a write_lock with irqs
586 * disabled. Since copy_from_user can fault and may sleep we
587 * need to copy to temporary buffer first
589 len = min(count, (size_t)(NAME_MAX_LEN - 1));
590 if (copy_from_user(buf, userbuf, len))
591 return -EFAULT;
593 buf[len] = 0;
595 write_lock_irqsave(&driver_name_lock, flags);
598 * Now handle the string we got from userspace very carefully.
599 * The rules are:
600 * - only use the first token we got
601 * - token delimiter is everything looking like a space
602 * character (' ', '\n', '\t' ...)
605 if (!isalnum(buf[0])) {
607 * If the first character userspace gave us is not
608 * alphanumerical then assume the filter should be
609 * switched off.
611 if (current_driver_name[0])
612 pr_info("DMA-API: switching off dma-debug driver filter\n");
613 current_driver_name[0] = 0;
614 current_driver = NULL;
615 goto out_unlock;
619 * Now parse out the first token and use it as the name for the
620 * driver to filter for.
622 for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
623 current_driver_name[i] = buf[i];
624 if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
625 break;
627 current_driver_name[i] = 0;
628 current_driver = NULL;
630 pr_info("DMA-API: enable driver filter for driver [%s]\n",
631 current_driver_name);
633 out_unlock:
634 write_unlock_irqrestore(&driver_name_lock, flags);
636 return count;
639 static const struct file_operations filter_fops = {
640 .read = filter_read,
641 .write = filter_write,
642 .llseek = default_llseek,
645 static int dma_debug_fs_init(void)
647 dma_debug_dent = debugfs_create_dir("dma-api", NULL);
648 if (!dma_debug_dent) {
649 pr_err("DMA-API: can not create debugfs directory\n");
650 return -ENOMEM;
653 global_disable_dent = debugfs_create_bool("disabled", 0444,
654 dma_debug_dent,
655 &global_disable);
656 if (!global_disable_dent)
657 goto out_err;
659 error_count_dent = debugfs_create_u32("error_count", 0444,
660 dma_debug_dent, &error_count);
661 if (!error_count_dent)
662 goto out_err;
664 show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
665 dma_debug_dent,
666 &show_all_errors);
667 if (!show_all_errors_dent)
668 goto out_err;
670 show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
671 dma_debug_dent,
672 &show_num_errors);
673 if (!show_num_errors_dent)
674 goto out_err;
676 num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
677 dma_debug_dent,
678 &num_free_entries);
679 if (!num_free_entries_dent)
680 goto out_err;
682 min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
683 dma_debug_dent,
684 &min_free_entries);
685 if (!min_free_entries_dent)
686 goto out_err;
688 filter_dent = debugfs_create_file("driver_filter", 0644,
689 dma_debug_dent, NULL, &filter_fops);
690 if (!filter_dent)
691 goto out_err;
693 return 0;
695 out_err:
696 debugfs_remove_recursive(dma_debug_dent);
698 return -ENOMEM;
701 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
703 struct dma_debug_entry *entry;
704 unsigned long flags;
705 int count = 0, i;
707 local_irq_save(flags);
709 for (i = 0; i < HASH_SIZE; ++i) {
710 spin_lock(&dma_entry_hash[i].lock);
711 list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
712 if (entry->dev == dev) {
713 count += 1;
714 *out_entry = entry;
717 spin_unlock(&dma_entry_hash[i].lock);
720 local_irq_restore(flags);
722 return count;
725 static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
727 struct device *dev = data;
728 struct dma_debug_entry *uninitialized_var(entry);
729 int count;
731 if (global_disable)
732 return 0;
734 switch (action) {
735 case BUS_NOTIFY_UNBOUND_DRIVER:
736 count = device_dma_allocations(dev, &entry);
737 if (count == 0)
738 break;
739 err_printk(dev, entry, "DMA-API: device driver has pending "
740 "DMA allocations while released from device "
741 "[count=%d]\n"
742 "One of leaked entries details: "
743 "[device address=0x%016llx] [size=%llu bytes] "
744 "[mapped with %s] [mapped as %s]\n",
745 count, entry->dev_addr, entry->size,
746 dir2name[entry->direction], type2name[entry->type]);
747 break;
748 default:
749 break;
752 return 0;
755 void dma_debug_add_bus(struct bus_type *bus)
757 struct notifier_block *nb;
759 if (global_disable)
760 return;
762 nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
763 if (nb == NULL) {
764 pr_err("dma_debug_add_bus: out of memory\n");
765 return;
768 nb->notifier_call = dma_debug_device_change;
770 bus_register_notifier(bus, nb);
774 * Let the architectures decide how many entries should be preallocated.
776 void dma_debug_init(u32 num_entries)
778 int i;
780 if (global_disable)
781 return;
783 for (i = 0; i < HASH_SIZE; ++i) {
784 INIT_LIST_HEAD(&dma_entry_hash[i].list);
785 spin_lock_init(&dma_entry_hash[i].lock);
788 if (dma_debug_fs_init() != 0) {
789 pr_err("DMA-API: error creating debugfs entries - disabling\n");
790 global_disable = true;
792 return;
795 if (req_entries)
796 num_entries = req_entries;
798 if (prealloc_memory(num_entries) != 0) {
799 pr_err("DMA-API: debugging out of memory error - disabled\n");
800 global_disable = true;
802 return;
805 nr_total_entries = num_free_entries;
807 pr_info("DMA-API: debugging enabled by kernel config\n");
810 static __init int dma_debug_cmdline(char *str)
812 if (!str)
813 return -EINVAL;
815 if (strncmp(str, "off", 3) == 0) {
816 pr_info("DMA-API: debugging disabled on kernel command line\n");
817 global_disable = true;
820 return 0;
823 static __init int dma_debug_entries_cmdline(char *str)
825 int res;
827 if (!str)
828 return -EINVAL;
830 res = get_option(&str, &req_entries);
832 if (!res)
833 req_entries = 0;
835 return 0;
838 __setup("dma_debug=", dma_debug_cmdline);
839 __setup("dma_debug_entries=", dma_debug_entries_cmdline);
841 static void check_unmap(struct dma_debug_entry *ref)
843 struct dma_debug_entry *entry;
844 struct hash_bucket *bucket;
845 unsigned long flags;
847 if (dma_mapping_error(ref->dev, ref->dev_addr)) {
848 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
849 "to free an invalid DMA memory address\n");
850 return;
853 bucket = get_hash_bucket(ref, &flags);
854 entry = bucket_find_exact(bucket, ref);
856 if (!entry) {
857 err_printk(ref->dev, NULL, "DMA-API: device driver tries "
858 "to free DMA memory it has not allocated "
859 "[device address=0x%016llx] [size=%llu bytes]\n",
860 ref->dev_addr, ref->size);
861 goto out;
864 if (ref->size != entry->size) {
865 err_printk(ref->dev, entry, "DMA-API: device driver frees "
866 "DMA memory with different size "
867 "[device address=0x%016llx] [map size=%llu bytes] "
868 "[unmap size=%llu bytes]\n",
869 ref->dev_addr, entry->size, ref->size);
872 if (ref->type != entry->type) {
873 err_printk(ref->dev, entry, "DMA-API: device driver frees "
874 "DMA memory with wrong function "
875 "[device address=0x%016llx] [size=%llu bytes] "
876 "[mapped as %s] [unmapped as %s]\n",
877 ref->dev_addr, ref->size,
878 type2name[entry->type], type2name[ref->type]);
879 } else if ((entry->type == dma_debug_coherent) &&
880 (ref->paddr != entry->paddr)) {
881 err_printk(ref->dev, entry, "DMA-API: device driver frees "
882 "DMA memory with different CPU address "
883 "[device address=0x%016llx] [size=%llu bytes] "
884 "[cpu alloc address=0x%016llx] "
885 "[cpu free address=0x%016llx]",
886 ref->dev_addr, ref->size,
887 (unsigned long long)entry->paddr,
888 (unsigned long long)ref->paddr);
891 if (ref->sg_call_ents && ref->type == dma_debug_sg &&
892 ref->sg_call_ents != entry->sg_call_ents) {
893 err_printk(ref->dev, entry, "DMA-API: device driver frees "
894 "DMA sg list with different entry count "
895 "[map count=%d] [unmap count=%d]\n",
896 entry->sg_call_ents, ref->sg_call_ents);
900 * This may be no bug in reality - but most implementations of the
901 * DMA API don't handle this properly, so check for it here
903 if (ref->direction != entry->direction) {
904 err_printk(ref->dev, entry, "DMA-API: device driver frees "
905 "DMA memory with different direction "
906 "[device address=0x%016llx] [size=%llu bytes] "
907 "[mapped with %s] [unmapped with %s]\n",
908 ref->dev_addr, ref->size,
909 dir2name[entry->direction],
910 dir2name[ref->direction]);
913 hash_bucket_del(entry);
914 dma_entry_free(entry);
916 out:
917 put_hash_bucket(bucket, &flags);
920 static void check_for_stack(struct device *dev, void *addr)
922 if (object_is_on_stack(addr))
923 err_printk(dev, NULL, "DMA-API: device driver maps memory from"
924 "stack [addr=%p]\n", addr);
927 static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
929 unsigned long a1 = (unsigned long)addr;
930 unsigned long b1 = a1 + len;
931 unsigned long a2 = (unsigned long)start;
932 unsigned long b2 = (unsigned long)end;
934 return !(b1 <= a2 || a1 >= b2);
937 static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
939 if (overlap(addr, len, _text, _etext) ||
940 overlap(addr, len, __start_rodata, __end_rodata))
941 err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
944 static void check_sync(struct device *dev,
945 struct dma_debug_entry *ref,
946 bool to_cpu)
948 struct dma_debug_entry *entry;
949 struct hash_bucket *bucket;
950 unsigned long flags;
952 bucket = get_hash_bucket(ref, &flags);
954 entry = bucket_find_contain(&bucket, ref, &flags);
956 if (!entry) {
957 err_printk(dev, NULL, "DMA-API: device driver tries "
958 "to sync DMA memory it has not allocated "
959 "[device address=0x%016llx] [size=%llu bytes]\n",
960 (unsigned long long)ref->dev_addr, ref->size);
961 goto out;
964 if (ref->size > entry->size) {
965 err_printk(dev, entry, "DMA-API: device driver syncs"
966 " DMA memory outside allocated range "
967 "[device address=0x%016llx] "
968 "[allocation size=%llu bytes] "
969 "[sync offset+size=%llu]\n",
970 entry->dev_addr, entry->size,
971 ref->size);
974 if (entry->direction == DMA_BIDIRECTIONAL)
975 goto out;
977 if (ref->direction != entry->direction) {
978 err_printk(dev, entry, "DMA-API: device driver syncs "
979 "DMA memory with different direction "
980 "[device address=0x%016llx] [size=%llu bytes] "
981 "[mapped with %s] [synced with %s]\n",
982 (unsigned long long)ref->dev_addr, entry->size,
983 dir2name[entry->direction],
984 dir2name[ref->direction]);
987 if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
988 !(ref->direction == DMA_TO_DEVICE))
989 err_printk(dev, entry, "DMA-API: device driver syncs "
990 "device read-only DMA memory for cpu "
991 "[device address=0x%016llx] [size=%llu bytes] "
992 "[mapped with %s] [synced with %s]\n",
993 (unsigned long long)ref->dev_addr, entry->size,
994 dir2name[entry->direction],
995 dir2name[ref->direction]);
997 if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
998 !(ref->direction == DMA_FROM_DEVICE))
999 err_printk(dev, entry, "DMA-API: device driver syncs "
1000 "device write-only DMA memory to device "
1001 "[device address=0x%016llx] [size=%llu bytes] "
1002 "[mapped with %s] [synced with %s]\n",
1003 (unsigned long long)ref->dev_addr, entry->size,
1004 dir2name[entry->direction],
1005 dir2name[ref->direction]);
1007 out:
1008 put_hash_bucket(bucket, &flags);
1011 void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1012 size_t size, int direction, dma_addr_t dma_addr,
1013 bool map_single)
1015 struct dma_debug_entry *entry;
1017 if (unlikely(global_disable))
1018 return;
1020 if (unlikely(dma_mapping_error(dev, dma_addr)))
1021 return;
1023 entry = dma_entry_alloc();
1024 if (!entry)
1025 return;
1027 entry->dev = dev;
1028 entry->type = dma_debug_page;
1029 entry->paddr = page_to_phys(page) + offset;
1030 entry->dev_addr = dma_addr;
1031 entry->size = size;
1032 entry->direction = direction;
1034 if (map_single)
1035 entry->type = dma_debug_single;
1037 if (!PageHighMem(page)) {
1038 void *addr = page_address(page) + offset;
1040 check_for_stack(dev, addr);
1041 check_for_illegal_area(dev, addr, size);
1044 add_dma_entry(entry);
1046 EXPORT_SYMBOL(debug_dma_map_page);
1048 void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
1049 size_t size, int direction, bool map_single)
1051 struct dma_debug_entry ref = {
1052 .type = dma_debug_page,
1053 .dev = dev,
1054 .dev_addr = addr,
1055 .size = size,
1056 .direction = direction,
1059 if (unlikely(global_disable))
1060 return;
1062 if (map_single)
1063 ref.type = dma_debug_single;
1065 check_unmap(&ref);
1067 EXPORT_SYMBOL(debug_dma_unmap_page);
1069 void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1070 int nents, int mapped_ents, int direction)
1072 struct dma_debug_entry *entry;
1073 struct scatterlist *s;
1074 int i;
1076 if (unlikely(global_disable))
1077 return;
1079 for_each_sg(sg, s, mapped_ents, i) {
1080 entry = dma_entry_alloc();
1081 if (!entry)
1082 return;
1084 entry->type = dma_debug_sg;
1085 entry->dev = dev;
1086 entry->paddr = sg_phys(s);
1087 entry->size = sg_dma_len(s);
1088 entry->dev_addr = sg_dma_address(s);
1089 entry->direction = direction;
1090 entry->sg_call_ents = nents;
1091 entry->sg_mapped_ents = mapped_ents;
1093 if (!PageHighMem(sg_page(s))) {
1094 check_for_stack(dev, sg_virt(s));
1095 check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
1098 add_dma_entry(entry);
1101 EXPORT_SYMBOL(debug_dma_map_sg);
1103 static int get_nr_mapped_entries(struct device *dev,
1104 struct dma_debug_entry *ref)
1106 struct dma_debug_entry *entry;
1107 struct hash_bucket *bucket;
1108 unsigned long flags;
1109 int mapped_ents;
1111 bucket = get_hash_bucket(ref, &flags);
1112 entry = bucket_find_exact(bucket, ref);
1113 mapped_ents = 0;
1115 if (entry)
1116 mapped_ents = entry->sg_mapped_ents;
1117 put_hash_bucket(bucket, &flags);
1119 return mapped_ents;
1122 void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1123 int nelems, int dir)
1125 struct scatterlist *s;
1126 int mapped_ents = 0, i;
1128 if (unlikely(global_disable))
1129 return;
1131 for_each_sg(sglist, s, nelems, i) {
1133 struct dma_debug_entry ref = {
1134 .type = dma_debug_sg,
1135 .dev = dev,
1136 .paddr = sg_phys(s),
1137 .dev_addr = sg_dma_address(s),
1138 .size = sg_dma_len(s),
1139 .direction = dir,
1140 .sg_call_ents = nelems,
1143 if (mapped_ents && i >= mapped_ents)
1144 break;
1146 if (!i)
1147 mapped_ents = get_nr_mapped_entries(dev, &ref);
1149 check_unmap(&ref);
1152 EXPORT_SYMBOL(debug_dma_unmap_sg);
1154 void debug_dma_alloc_coherent(struct device *dev, size_t size,
1155 dma_addr_t dma_addr, void *virt)
1157 struct dma_debug_entry *entry;
1159 if (unlikely(global_disable))
1160 return;
1162 if (unlikely(virt == NULL))
1163 return;
1165 entry = dma_entry_alloc();
1166 if (!entry)
1167 return;
1169 entry->type = dma_debug_coherent;
1170 entry->dev = dev;
1171 entry->paddr = virt_to_phys(virt);
1172 entry->size = size;
1173 entry->dev_addr = dma_addr;
1174 entry->direction = DMA_BIDIRECTIONAL;
1176 add_dma_entry(entry);
1178 EXPORT_SYMBOL(debug_dma_alloc_coherent);
1180 void debug_dma_free_coherent(struct device *dev, size_t size,
1181 void *virt, dma_addr_t addr)
1183 struct dma_debug_entry ref = {
1184 .type = dma_debug_coherent,
1185 .dev = dev,
1186 .paddr = virt_to_phys(virt),
1187 .dev_addr = addr,
1188 .size = size,
1189 .direction = DMA_BIDIRECTIONAL,
1192 if (unlikely(global_disable))
1193 return;
1195 check_unmap(&ref);
1197 EXPORT_SYMBOL(debug_dma_free_coherent);
1199 void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1200 size_t size, int direction)
1202 struct dma_debug_entry ref;
1204 if (unlikely(global_disable))
1205 return;
1207 ref.type = dma_debug_single;
1208 ref.dev = dev;
1209 ref.dev_addr = dma_handle;
1210 ref.size = size;
1211 ref.direction = direction;
1212 ref.sg_call_ents = 0;
1214 check_sync(dev, &ref, true);
1216 EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
1218 void debug_dma_sync_single_for_device(struct device *dev,
1219 dma_addr_t dma_handle, size_t size,
1220 int direction)
1222 struct dma_debug_entry ref;
1224 if (unlikely(global_disable))
1225 return;
1227 ref.type = dma_debug_single;
1228 ref.dev = dev;
1229 ref.dev_addr = dma_handle;
1230 ref.size = size;
1231 ref.direction = direction;
1232 ref.sg_call_ents = 0;
1234 check_sync(dev, &ref, false);
1236 EXPORT_SYMBOL(debug_dma_sync_single_for_device);
1238 void debug_dma_sync_single_range_for_cpu(struct device *dev,
1239 dma_addr_t dma_handle,
1240 unsigned long offset, size_t size,
1241 int direction)
1243 struct dma_debug_entry ref;
1245 if (unlikely(global_disable))
1246 return;
1248 ref.type = dma_debug_single;
1249 ref.dev = dev;
1250 ref.dev_addr = dma_handle;
1251 ref.size = offset + size;
1252 ref.direction = direction;
1253 ref.sg_call_ents = 0;
1255 check_sync(dev, &ref, true);
1257 EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
1259 void debug_dma_sync_single_range_for_device(struct device *dev,
1260 dma_addr_t dma_handle,
1261 unsigned long offset,
1262 size_t size, int direction)
1264 struct dma_debug_entry ref;
1266 if (unlikely(global_disable))
1267 return;
1269 ref.type = dma_debug_single;
1270 ref.dev = dev;
1271 ref.dev_addr = dma_handle;
1272 ref.size = offset + size;
1273 ref.direction = direction;
1274 ref.sg_call_ents = 0;
1276 check_sync(dev, &ref, false);
1278 EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
1280 void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1281 int nelems, int direction)
1283 struct scatterlist *s;
1284 int mapped_ents = 0, i;
1286 if (unlikely(global_disable))
1287 return;
1289 for_each_sg(sg, s, nelems, i) {
1291 struct dma_debug_entry ref = {
1292 .type = dma_debug_sg,
1293 .dev = dev,
1294 .paddr = sg_phys(s),
1295 .dev_addr = sg_dma_address(s),
1296 .size = sg_dma_len(s),
1297 .direction = direction,
1298 .sg_call_ents = nelems,
1301 if (!i)
1302 mapped_ents = get_nr_mapped_entries(dev, &ref);
1304 if (i >= mapped_ents)
1305 break;
1307 check_sync(dev, &ref, true);
1310 EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
1312 void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1313 int nelems, int direction)
1315 struct scatterlist *s;
1316 int mapped_ents = 0, i;
1318 if (unlikely(global_disable))
1319 return;
1321 for_each_sg(sg, s, nelems, i) {
1323 struct dma_debug_entry ref = {
1324 .type = dma_debug_sg,
1325 .dev = dev,
1326 .paddr = sg_phys(s),
1327 .dev_addr = sg_dma_address(s),
1328 .size = sg_dma_len(s),
1329 .direction = direction,
1330 .sg_call_ents = nelems,
1332 if (!i)
1333 mapped_ents = get_nr_mapped_entries(dev, &ref);
1335 if (i >= mapped_ents)
1336 break;
1338 check_sync(dev, &ref, false);
1341 EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
1343 static int __init dma_debug_driver_setup(char *str)
1345 int i;
1347 for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1348 current_driver_name[i] = *str;
1349 if (*str == 0)
1350 break;
1353 if (current_driver_name[0])
1354 pr_info("DMA-API: enable driver filter for driver [%s]\n",
1355 current_driver_name);
1358 return 1;
1360 __setup("dma_debug_driver=", dma_debug_driver_setup);