1	// SPDX-License-Identifier: GPL-2.0-only
2	/*
3	* Copyright (C) 2008 Advanced Micro Devices, Inc.
4	*
5	* Author: Joerg Roedel <joerg.roedel@amd.com>
6	*/
7
8	#define pr_fmt(fmt) "DMA-API: " fmt
9
10	#include <linux/sched/task_stack.h>
11	#include <linux/scatterlist.h>
12	#include <linux/dma-map-ops.h>
13	#include <linux/sched/task.h>
14	#include <linux/stacktrace.h>
15	#include <linux/spinlock.h>
16	#include <linux/vmalloc.h>
17	#include <linux/debugfs.h>
18	#include <linux/uaccess.h>
19	#include <linux/export.h>
20	#include <linux/device.h>
21	#include <linux/types.h>
22	#include <linux/sched.h>
23	#include <linux/ctype.h>
24	#include <linux/list.h>
25	#include <linux/slab.h>
26	#include <asm/sections.h>
27	#include "debug.h"
28
29	#define HASH_SIZE 16384ULL
30	#define HASH_FN_SHIFT 13
31	#define HASH_FN_MASK (HASH_SIZE - 1)
32
33	#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
34	/* If the pool runs out, add this many new entries at once */
35	#define DMA_DEBUG_DYNAMIC_ENTRIES (PAGE_SIZE / sizeof(struct dma_debug_entry))
36
37	enum {
38	dma_debug_single,
39	dma_debug_sg,
40	dma_debug_coherent,
41	dma_debug_resource,
42	};
43
44	enum map_err_types {
45	MAP_ERR_CHECK_NOT_APPLICABLE,
46	MAP_ERR_NOT_CHECKED,
47	MAP_ERR_CHECKED,
48	};
49
50	#define DMA_DEBUG_STACKTRACE_ENTRIES 5
51
52	/**
53	* struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
54	* @list: node on pre-allocated free_entries list
55	* @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
56	* @dev_addr: dma address
57	* @size: length of the mapping
58	* @type: single, page, sg, coherent
59	* @direction: enum dma_data_direction
60	* @sg_call_ents: 'nents' from dma_map_sg
61	* @sg_mapped_ents: 'mapped_ents' from dma_map_sg
62	* @pfn: page frame of the start address
63	* @offset: offset of mapping relative to pfn
64	* @map_err_type: track whether dma_mapping_error() was checked
65	* @stack_len: number of backtrace entries in @stack_entries
66	* @stack_entries: stack of backtrace history
67	*/
68	struct dma_debug_entry {
69	struct list_head list;
70	struct device *dev;
71	u64 dev_addr;
72	u64 size;
73	int type;
74	int direction;
75	int sg_call_ents;
76	int sg_mapped_ents;
77	unsigned long pfn;
78	size_t offset;
79	enum map_err_types map_err_type;
80	#ifdef CONFIG_STACKTRACE
81	unsigned int stack_len;
82	unsigned long stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
83	#endif
84	} ____cacheline_aligned_in_smp;
85
86	typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
87
88	struct hash_bucket {
89	struct list_head list;
90	spinlock_t lock;
91	};
92
93	/* Hash list to save the allocated dma addresses */
94	static struct hash_bucket dma_entry_hash[HASH_SIZE];
95	/* List of pre-allocated dma_debug_entry's */
96	static LIST_HEAD(free_entries);
97	/* Lock for the list above */
98	static DEFINE_SPINLOCK(free_entries_lock);
99
100	/* Global disable flag - will be set in case of an error */
101	static bool global_disable __read_mostly;
102
103	/* Early initialization disable flag, set at the end of dma_debug_init */
104	static bool dma_debug_initialized __read_mostly;
105
106	static inline bool dma_debug_disabled(void)
107	{
108	return global_disable || !dma_debug_initialized;
109	}
110
111	/* Global error count */
112	static u32 error_count;
113
114	/* Global error show enable*/
115	static u32 show_all_errors __read_mostly;
116	/* Number of errors to show */
117	static u32 show_num_errors = 1;
118
119	static u32 num_free_entries;
120	static u32 min_free_entries;
121	static u32 nr_total_entries;
122
123	/* number of preallocated entries requested by kernel cmdline */
124	static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
125
126	/* per-driver filter related state */
127
128	#define NAME_MAX_LEN 64
129
130	static char current_driver_name[NAME_MAX_LEN] __read_mostly;
131	static struct device_driver *current_driver __read_mostly;
132
133	static DEFINE_RWLOCK(driver_name_lock);
134
135	static const char *const maperr2str[] = {
136	[MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
137	[MAP_ERR_NOT_CHECKED] = "dma map error not checked",
138	[MAP_ERR_CHECKED] = "dma map error checked",
139	};
140
141	static const char *type2name[] = {
142	[dma_debug_single] = "single",
143	[dma_debug_sg] = "scatter-gather",
144	[dma_debug_coherent] = "coherent",
145	[dma_debug_resource] = "resource",
146	};
147
148	static const char *dir2name[] = {
149	[DMA_BIDIRECTIONAL] = "DMA_BIDIRECTIONAL",
150	[DMA_TO_DEVICE] = "DMA_TO_DEVICE",
151	[DMA_FROM_DEVICE] = "DMA_FROM_DEVICE",
152	[DMA_NONE] = "DMA_NONE",
153	};
154
155	/*
156	* The access to some variables in this macro is racy. We can't use atomic_t
157	* here because all these variables are exported to debugfs. Some of them even
158	* writeable. This is also the reason why a lock won't help much. But anyway,
159	* the races are no big deal. Here is why:
160	*
161	* error_count: the addition is racy, but the worst thing that can happen is
162	* that we don't count some errors
163	* show_num_errors: the subtraction is racy. Also no big deal because in
164	* worst case this will result in one warning more in the
165	* system log than the user configured. This variable is
166	* writeable via debugfs.
167	*/
168	static inline void dump_entry_trace(struct dma_debug_entry *entry)
169	{
170	#ifdef CONFIG_STACKTRACE
171	if (entry) {
172	pr_warn("Mapped at:\n");
173	stack_trace_print(trace: entry->stack_entries, nr_entries: entry->stack_len, spaces: 0);
174	}
175	#endif
176	}
177
178	static bool driver_filter(struct device *dev)
179	{
180	struct device_driver *drv;
181	unsigned long flags;
182	bool ret;
183
184	/* driver filter off */
185	if (likely(!current_driver_name[0]))
186	return true;
187
188	/* driver filter on and initialized */
189	if (current_driver && dev && dev->driver == current_driver)
190	return true;
191
192	/* driver filter on, but we can't filter on a NULL device... */
193	if (!dev)
194	return false;
195
196	if (current_driver || !current_driver_name[0])
197	return false;
198
199	/* driver filter on but not yet initialized */
200	drv = dev->driver;
201	if (!drv)
202	return false;
203
204	/* lock to protect against change of current_driver_name */
205	read_lock_irqsave(&driver_name_lock, flags);
206
207	ret = false;
208	if (drv->name &&
209	strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
210	current_driver = drv;
211	ret = true;
212	}
213
214	read_unlock_irqrestore(&driver_name_lock, flags);
215
216	return ret;
217	}
218
219	#define err_printk(dev, entry, format, arg...) do { \
220	error_count += 1; \
221	if (driver_filter(dev) && \
222	(show_all_errors || show_num_errors > 0)) { \
223	WARN(1, pr_fmt("%s %s: ") format, \
224	dev ? dev_driver_string(dev) : "NULL", \
225	dev ? dev_name(dev) : "NULL", ## arg); \
226	dump_entry_trace(entry); \
227	} \
228	if (!show_all_errors && show_num_errors > 0) \
229	show_num_errors -= 1; \
230	} while (0);
231
232	/*
233	* Hash related functions
234	*
235	* Every DMA-API request is saved into a struct dma_debug_entry. To
236	* have quick access to these structs they are stored into a hash.
237	*/
238	static int hash_fn(struct dma_debug_entry *entry)
239	{
240	/*
241	* Hash function is based on the dma address.
242	* We use bits 20-27 here as the index into the hash
243	*/
244	return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
245	}
246
247	/*
248	* Request exclusive access to a hash bucket for a given dma_debug_entry.
249	*/
250	static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
251	unsigned long *flags)
252	__acquires(&dma_entry_hash[idx].lock)
253	{
254	int idx = hash_fn(entry);
255	unsigned long __flags;
256
257	spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
258	*flags = __flags;
259	return &dma_entry_hash[idx];
260	}
261
262	/*
263	* Give up exclusive access to the hash bucket
264	*/
265	static void put_hash_bucket(struct hash_bucket *bucket,
266	unsigned long flags)
267	__releases(&bucket->lock)
268	{
269	spin_unlock_irqrestore(lock: &bucket->lock, flags);
270	}
271
272	static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
273	{
274	return ((a->dev_addr == b->dev_addr) &&
275	(a->dev == b->dev)) ? true : false;
276	}
277
278	static bool containing_match(struct dma_debug_entry *a,
279	struct dma_debug_entry *b)
280	{
281	if (a->dev != b->dev)
282	return false;
283
284	if ((b->dev_addr <= a->dev_addr) &&
285	((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
286	return true;
287
288	return false;
289	}
290
291	/*
292	* Search a given entry in the hash bucket list
293	*/
294	static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
295	struct dma_debug_entry *ref,
296	match_fn match)
297	{
298	struct dma_debug_entry *entry, *ret = NULL;
299	int matches = 0, match_lvl, last_lvl = -1;
300
301	list_for_each_entry(entry, &bucket->list, list) {
302	if (!match(ref, entry))
303	continue;
304
305	/*
306	* Some drivers map the same physical address multiple
307	* times. Without a hardware IOMMU this results in the
308	* same device addresses being put into the dma-debug
309	* hash multiple times too. This can result in false
310	* positives being reported. Therefore we implement a
311	* best-fit algorithm here which returns the entry from
312	* the hash which fits best to the reference value
313	* instead of the first-fit.
314	*/
315	matches += 1;
316	match_lvl = 0;
317	entry->size == ref->size ? ++match_lvl : 0;
318	entry->type == ref->type ? ++match_lvl : 0;
319	entry->direction == ref->direction ? ++match_lvl : 0;
320	entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
321
322	if (match_lvl == 4) {
323	/* perfect-fit - return the result */
324	return entry;
325	} else if (match_lvl > last_lvl) {
326	/*
327	* We found an entry that fits better then the
328	* previous one or it is the 1st match.
329	*/
330	last_lvl = match_lvl;
331	ret = entry;
332	}
333	}
334
335	/*
336	* If we have multiple matches but no perfect-fit, just return
337	* NULL.
338	*/
339	ret = (matches == 1) ? ret : NULL;
340
341	return ret;
342	}
343
344	static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
345	struct dma_debug_entry *ref)
346	{
347	return __hash_bucket_find(bucket, ref, match: exact_match);
348	}
349
350	static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
351	struct dma_debug_entry *ref,
352	unsigned long *flags)
353	{
354
355	struct dma_debug_entry *entry, index = *ref;
356	int limit = min(HASH_SIZE, (index.dev_addr >> HASH_FN_SHIFT) + 1);
357
358	for (int i = 0; i < limit; i++) {
359	entry = __hash_bucket_find(bucket: *bucket, ref, match: containing_match);
360
361	if (entry)
362	return entry;
363
364	/*
365	* Nothing found, go back a hash bucket
366	*/
367	put_hash_bucket(bucket: *bucket, flags: *flags);
368	index.dev_addr -= (1 << HASH_FN_SHIFT);
369	*bucket = get_hash_bucket(entry: &index, flags);
370	}
371
372	return NULL;
373	}
374
375	/*
376	* Add an entry to a hash bucket
377	*/
378	static void hash_bucket_add(struct hash_bucket *bucket,
379	struct dma_debug_entry *entry)
380	{
381	list_add_tail(new: &entry->list, head: &bucket->list);
382	}
383
384	/*
385	* Remove entry from a hash bucket list
386	*/
387	static void hash_bucket_del(struct dma_debug_entry *entry)
388	{
389	list_del(entry: &entry->list);
390	}
391
392	static unsigned long long phys_addr(struct dma_debug_entry *entry)
393	{
394	if (entry->type == dma_debug_resource)
395	return __pfn_to_phys(entry->pfn) + entry->offset;
396
397	return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
398	}
399
400	/*
401	* For each mapping (initial cacheline in the case of
402	* dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
403	* scatterlist, or the cacheline specified in dma_map_single) insert
404	* into this tree using the cacheline as the key. At
405	* dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If
406	* the entry already exists at insertion time add a tag as a reference
407	* count for the overlapping mappings. For now, the overlap tracking
408	* just ensures that 'unmaps' balance 'maps' before marking the
409	* cacheline idle, but we should also be flagging overlaps as an API
410	* violation.
411	*
412	* Memory usage is mostly constrained by the maximum number of available
413	* dma-debug entries in that we need a free dma_debug_entry before
414	* inserting into the tree. In the case of dma_map_page and
415	* dma_alloc_coherent there is only one dma_debug_entry and one
416	* dma_active_cacheline entry to track per event. dma_map_sg(), on the
417	* other hand, consumes a single dma_debug_entry, but inserts 'nents'
418	* entries into the tree.
419	*/
420	static RADIX_TREE(dma_active_cacheline, GFP_ATOMIC);
421	static DEFINE_SPINLOCK(radix_lock);
422	#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
423	#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
424	#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
425
426	static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
427	{
428	return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
429	(entry->offset >> L1_CACHE_SHIFT);
430	}
431
432	static int active_cacheline_read_overlap(phys_addr_t cln)
433	{
434	int overlap = 0, i;
435
436	for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
437	if (radix_tree_tag_get(&dma_active_cacheline, index: cln, tag: i))
438	overlap |= 1 << i;
439	return overlap;
440	}
441
442	static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
443	{
444	int i;
445
446	if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
447	return overlap;
448
449	for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
450	if (overlap & 1 << i)
451	radix_tree_tag_set(&dma_active_cacheline, index: cln, tag: i);
452	else
453	radix_tree_tag_clear(&dma_active_cacheline, index: cln, tag: i);
454
455	return overlap;
456	}
457
458	static void active_cacheline_inc_overlap(phys_addr_t cln)
459	{
460	int overlap = active_cacheline_read_overlap(cln);
461
462	overlap = active_cacheline_set_overlap(cln, overlap: ++overlap);
463
464	/* If we overflowed the overlap counter then we're potentially
465	* leaking dma-mappings.
466	*/
467	WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
468	pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
469	ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
470	}
471
472	static int active_cacheline_dec_overlap(phys_addr_t cln)
473	{
474	int overlap = active_cacheline_read_overlap(cln);
475
476	return active_cacheline_set_overlap(cln, overlap: --overlap);
477	}
478
479	static int active_cacheline_insert(struct dma_debug_entry *entry)
480	{
481	phys_addr_t cln = to_cacheline_number(entry);
482	unsigned long flags;
483	int rc;
484
485	/* If the device is not writing memory then we don't have any
486	* concerns about the cpu consuming stale data. This mitigates
487	* legitimate usages of overlapping mappings.
488	*/
489	if (entry->direction == DMA_TO_DEVICE)
490	return 0;
491
492	spin_lock_irqsave(&radix_lock, flags);
493	rc = radix_tree_insert(&dma_active_cacheline, index: cln, entry);
494	if (rc == -EEXIST)
495	active_cacheline_inc_overlap(cln);
496	spin_unlock_irqrestore(lock: &radix_lock, flags);
497
498	return rc;
499	}
500
501	static void active_cacheline_remove(struct dma_debug_entry *entry)
502	{
503	phys_addr_t cln = to_cacheline_number(entry);
504	unsigned long flags;
505
506	/* ...mirror the insert case */
507	if (entry->direction == DMA_TO_DEVICE)
508	return;
509
510	spin_lock_irqsave(&radix_lock, flags);
511	/* since we are counting overlaps the final put of the
512	* cacheline will occur when the overlap count is 0.
513	* active_cacheline_dec_overlap() returns -1 in that case
514	*/
515	if (active_cacheline_dec_overlap(cln) < 0)
516	radix_tree_delete(&dma_active_cacheline, cln);
517	spin_unlock_irqrestore(lock: &radix_lock, flags);
518	}
519
520	/*
521	* Dump mappings entries on kernel space for debugging purposes
522	*/
523	void debug_dma_dump_mappings(struct device *dev)
524	{
525	int idx;
526	phys_addr_t cln;
527
528	for (idx = 0; idx < HASH_SIZE; idx++) {
529	struct hash_bucket *bucket = &dma_entry_hash[idx];
530	struct dma_debug_entry *entry;
531	unsigned long flags;
532
533	spin_lock_irqsave(&bucket->lock, flags);
534	list_for_each_entry(entry, &bucket->list, list) {
535	if (!dev || dev == entry->dev) {
536	cln = to_cacheline_number(entry);
537	dev_info(entry->dev,
538	"%s idx %d P=%llx N=%lx D=%llx L=%llx cln=%pa %s %s\n",
539	type2name[entry->type], idx,
540	phys_addr(entry), entry->pfn,
541	entry->dev_addr, entry->size,
542	&cln, dir2name[entry->direction],
543	maperr2str[entry->map_err_type]);
544	}
545	}
546	spin_unlock_irqrestore(lock: &bucket->lock, flags);
547
548	cond_resched();
549	}
550	}
551
552	/*
553	* Dump mappings entries on user space via debugfs
554	*/
555	static int dump_show(struct seq_file *seq, void *v)
556	{
557	int idx;
558	phys_addr_t cln;
559
560	for (idx = 0; idx < HASH_SIZE; idx++) {
561	struct hash_bucket *bucket = &dma_entry_hash[idx];
562	struct dma_debug_entry *entry;
563	unsigned long flags;
564
565	spin_lock_irqsave(&bucket->lock, flags);
566	list_for_each_entry(entry, &bucket->list, list) {
567	cln = to_cacheline_number(entry);
568	seq_printf(m: seq,
569	fmt: "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx cln=%pa %s %s\n",
570	dev_driver_string(dev: entry->dev),
571	dev_name(dev: entry->dev),
572	type2name[entry->type], idx,
573	phys_addr(entry), entry->pfn,
574	entry->dev_addr, entry->size,
575	&cln, dir2name[entry->direction],
576	maperr2str[entry->map_err_type]);
577	}
578	spin_unlock_irqrestore(lock: &bucket->lock, flags);
579	}
580	return 0;
581	}
582	DEFINE_SHOW_ATTRIBUTE(dump);
583
584	/*
585	* Wrapper function for adding an entry to the hash.
586	* This function takes care of locking itself.
587	*/
588	static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
589	{
590	struct hash_bucket *bucket;
591	unsigned long flags;
592	int rc;
593
594	bucket = get_hash_bucket(entry, flags: &flags);
595	hash_bucket_add(bucket, entry);
596	put_hash_bucket(bucket, flags);
597
598	rc = active_cacheline_insert(entry);
599	if (rc == -ENOMEM) {
600	pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n");
601	global_disable = true;
602	} else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
603	err_printk(entry->dev, entry,
604	"cacheline tracking EEXIST, overlapping mappings aren't supported\n");
605	}
606	}
607
608	static int dma_debug_create_entries(gfp_t gfp)
609	{
610	struct dma_debug_entry *entry;
611	int i;
612
613	entry = (void *)get_zeroed_page(gfp_mask: gfp);
614	if (!entry)
615	return -ENOMEM;
616
617	for (i = 0; i < DMA_DEBUG_DYNAMIC_ENTRIES; i++)
618	list_add_tail(new: &entry[i].list, head: &free_entries);
619
620	num_free_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
621	nr_total_entries += DMA_DEBUG_DYNAMIC_ENTRIES;
622
623	return 0;
624	}
625
626	static struct dma_debug_entry *__dma_entry_alloc(void)
627	{
628	struct dma_debug_entry *entry;
629
630	entry = list_entry(free_entries.next, struct dma_debug_entry, list);
631	list_del(entry: &entry->list);
632	memset(entry, 0, sizeof(*entry));
633
634	num_free_entries -= 1;
635	if (num_free_entries < min_free_entries)
636	min_free_entries = num_free_entries;
637
638	return entry;
639	}
640
641	/*
642	* This should be called outside of free_entries_lock scope to avoid potential
643	* deadlocks with serial consoles that use DMA.
644	*/
645	static void __dma_entry_alloc_check_leak(u32 nr_entries)
646	{
647	u32 tmp = nr_entries % nr_prealloc_entries;
648
649	/* Shout each time we tick over some multiple of the initial pool */
650	if (tmp < DMA_DEBUG_DYNAMIC_ENTRIES) {
651	pr_info("dma_debug_entry pool grown to %u (%u00%%)\n",
652	nr_entries,
653	(nr_entries / nr_prealloc_entries));
654	}
655	}
656
657	/* struct dma_entry allocator
658	*
659	* The next two functions implement the allocator for
660	* struct dma_debug_entries.
661	*/
662	static struct dma_debug_entry *dma_entry_alloc(void)
663	{
664	bool alloc_check_leak = false;
665	struct dma_debug_entry *entry;
666	unsigned long flags;
667	u32 nr_entries;
668
669	spin_lock_irqsave(&free_entries_lock, flags);
670	if (num_free_entries == 0) {
671	if (dma_debug_create_entries(GFP_ATOMIC)) {
672	global_disable = true;
673	spin_unlock_irqrestore(lock: &free_entries_lock, flags);
674	pr_err("debugging out of memory - disabling\n");
675	return NULL;
676	}
677	alloc_check_leak = true;
678	nr_entries = nr_total_entries;
679	}
680
681	entry = __dma_entry_alloc();
682
683	spin_unlock_irqrestore(lock: &free_entries_lock, flags);
684
685	if (alloc_check_leak)
686	__dma_entry_alloc_check_leak(nr_entries);
687
688	#ifdef CONFIG_STACKTRACE
689	entry->stack_len = stack_trace_save(store: entry->stack_entries,
690	ARRAY_SIZE(entry->stack_entries),
691	skipnr: 1);
692	#endif
693	return entry;
694	}
695
696	static void dma_entry_free(struct dma_debug_entry *entry)
697	{
698	unsigned long flags;
699
700	active_cacheline_remove(entry);
701
702	/*
703	* add to beginning of the list - this way the entries are
704	* more likely cache hot when they are reallocated.
705	*/
706	spin_lock_irqsave(&free_entries_lock, flags);
707	list_add(new: &entry->list, head: &free_entries);
708	num_free_entries += 1;
709	spin_unlock_irqrestore(lock: &free_entries_lock, flags);
710	}
711
712	/*
713	* DMA-API debugging init code
714	*
715	* The init code does two things:
716	* 1. Initialize core data structures
717	* 2. Preallocate a given number of dma_debug_entry structs
718	*/
719
720	static ssize_t filter_read(struct file *file, char __user *user_buf,
721	size_t count, loff_t *ppos)
722	{
723	char buf[NAME_MAX_LEN + 1];
724	unsigned long flags;
725	int len;
726
727	if (!current_driver_name[0])
728	return 0;
729
730	/*
731	* We can't copy to userspace directly because current_driver_name can
732	* only be read under the driver_name_lock with irqs disabled. So
733	* create a temporary copy first.
734	*/
735	read_lock_irqsave(&driver_name_lock, flags);
736	len = scnprintf(buf, NAME_MAX_LEN + 1, fmt: "%s\n", current_driver_name);
737	read_unlock_irqrestore(&driver_name_lock, flags);
738
739	return simple_read_from_buffer(to: user_buf, count, ppos, from: buf, available: len);
740	}
741
742	static ssize_t filter_write(struct file *file, const char __user *userbuf,
743	size_t count, loff_t *ppos)
744	{
745	char buf[NAME_MAX_LEN];
746	unsigned long flags;
747	size_t len;
748	int i;
749
750	/*
751	* We can't copy from userspace directly. Access to
752	* current_driver_name is protected with a write_lock with irqs
753	* disabled. Since copy_from_user can fault and may sleep we
754	* need to copy to temporary buffer first
755	*/
756	len = min(count, (size_t)(NAME_MAX_LEN - 1));
757	if (copy_from_user(to: buf, from: userbuf, n: len))
758	return -EFAULT;
759
760	buf[len] = 0;
761
762	write_lock_irqsave(&driver_name_lock, flags);
763
764	/*
765	* Now handle the string we got from userspace very carefully.
766	* The rules are:
767	* - only use the first token we got
768	* - token delimiter is everything looking like a space
769	* character (' ', '\n', '\t' ...)
770	*
771	*/
772	if (!isalnum(buf[0])) {
773	/*
774	* If the first character userspace gave us is not
775	* alphanumerical then assume the filter should be
776	* switched off.
777	*/
778	if (current_driver_name[0])
779	pr_info("switching off dma-debug driver filter\n");
780	current_driver_name[0] = 0;
781	current_driver = NULL;
782	goto out_unlock;
783	}
784
785	/*
786	* Now parse out the first token and use it as the name for the
787	* driver to filter for.
788	*/
789	for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
790	current_driver_name[i] = buf[i];
791	if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
792	break;
793	}
794	current_driver_name[i] = 0;
795	current_driver = NULL;
796
797	pr_info("enable driver filter for driver [%s]\n",
798	current_driver_name);
799
800	out_unlock:
801	write_unlock_irqrestore(&driver_name_lock, flags);
802
803	return count;
804	}
805
806	static const struct file_operations filter_fops = {
807	.read = filter_read,
808	.write = filter_write,
809	.llseek = default_llseek,
810	};
811
812	static int __init dma_debug_fs_init(void)
813	{
814	struct dentry *dentry = debugfs_create_dir(name: "dma-api", NULL);
815
816	debugfs_create_bool(name: "disabled", mode: 0444, parent: dentry, value: &global_disable);
817	debugfs_create_u32(name: "error_count", mode: 0444, parent: dentry, value: &error_count);
818	debugfs_create_u32(name: "all_errors", mode: 0644, parent: dentry, value: &show_all_errors);
819	debugfs_create_u32(name: "num_errors", mode: 0644, parent: dentry, value: &show_num_errors);
820	debugfs_create_u32(name: "num_free_entries", mode: 0444, parent: dentry, value: &num_free_entries);
821	debugfs_create_u32(name: "min_free_entries", mode: 0444, parent: dentry, value: &min_free_entries);
822	debugfs_create_u32(name: "nr_total_entries", mode: 0444, parent: dentry, value: &nr_total_entries);
823	debugfs_create_file(name: "driver_filter", mode: 0644, parent: dentry, NULL, fops: &filter_fops);
824	debugfs_create_file(name: "dump", mode: 0444, parent: dentry, NULL, fops: &dump_fops);
825
826	return 0;
827	}
828	core_initcall_sync(dma_debug_fs_init);
829
830	static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
831	{
832	struct dma_debug_entry *entry;
833	unsigned long flags;
834	int count = 0, i;
835
836	for (i = 0; i < HASH_SIZE; ++i) {
837	spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
838	list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
839	if (entry->dev == dev) {
840	count += 1;
841	*out_entry = entry;
842	}
843	}
844	spin_unlock_irqrestore(lock: &dma_entry_hash[i].lock, flags);
845	}
846
847	return count;
848	}
849
850	static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
851	{
852	struct device *dev = data;
853	struct dma_debug_entry *entry;
854	int count;
855
856	if (dma_debug_disabled())
857	return 0;
858
859	switch (action) {
860	case BUS_NOTIFY_UNBOUND_DRIVER:
861	count = device_dma_allocations(dev, out_entry: &entry);
862	if (count == 0)
863	break;
864	err_printk(dev, entry, "device driver has pending "
865	"DMA allocations while released from device "
866	"[count=%d]\n"
867	"One of leaked entries details: "
868	"[device address=0x%016llx] [size=%llu bytes] "
869	"[mapped with %s] [mapped as %s]\n",
870	count, entry->dev_addr, entry->size,
871	dir2name[entry->direction], type2name[entry->type]);
872	break;
873	default:
874	break;
875	}
876
877	return 0;
878	}
879
880	void dma_debug_add_bus(const struct bus_type *bus)
881	{
882	struct notifier_block *nb;
883
884	if (dma_debug_disabled())
885	return;
886
887	nb = kzalloc(size: sizeof(struct notifier_block), GFP_KERNEL);
888	if (nb == NULL) {
889	pr_err("dma_debug_add_bus: out of memory\n");
890	return;
891	}
892
893	nb->notifier_call = dma_debug_device_change;
894
895	bus_register_notifier(bus, nb);
896	}
897
898	static int dma_debug_init(void)
899	{
900	int i, nr_pages;
901
902	/* Do not use dma_debug_initialized here, since we really want to be
903	* called to set dma_debug_initialized
904	*/
905	if (global_disable)
906	return 0;
907
908	for (i = 0; i < HASH_SIZE; ++i) {
909	INIT_LIST_HEAD(list: &dma_entry_hash[i].list);
910	spin_lock_init(&dma_entry_hash[i].lock);
911	}
912
913	nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES);
914	for (i = 0; i < nr_pages; ++i)
915	dma_debug_create_entries(GFP_KERNEL);
916	if (num_free_entries >= nr_prealloc_entries) {
917	pr_info("preallocated %d debug entries\n", nr_total_entries);
918	} else if (num_free_entries > 0) {
919	pr_warn("%d debug entries requested but only %d allocated\n",
920	nr_prealloc_entries, nr_total_entries);
921	} else {
922	pr_err("debugging out of memory error - disabled\n");
923	global_disable = true;
924
925	return 0;
926	}
927	min_free_entries = num_free_entries;
928
929	dma_debug_initialized = true;
930
931	pr_info("debugging enabled by kernel config\n");
932	return 0;
933	}
934	core_initcall(dma_debug_init);
935
936	static __init int dma_debug_cmdline(char *str)
937	{
938	if (!str)
939	return -EINVAL;
940
941	if (strncmp(str, "off", 3) == 0) {
942	pr_info("debugging disabled on kernel command line\n");
943	global_disable = true;
944	}
945
946	return 1;
947	}
948
949	static __init int dma_debug_entries_cmdline(char *str)
950	{
951	if (!str)
952	return -EINVAL;
953	if (!get_option(str: &str, pint: &nr_prealloc_entries))
954	nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
955	return 1;
956	}
957
958	__setup("dma_debug=", dma_debug_cmdline);
959	__setup("dma_debug_entries=", dma_debug_entries_cmdline);
960
961	static void check_unmap(struct dma_debug_entry *ref)
962	{
963	struct dma_debug_entry *entry;
964	struct hash_bucket *bucket;
965	unsigned long flags;
966
967	bucket = get_hash_bucket(entry: ref, flags: &flags);
968	entry = bucket_find_exact(bucket, ref);
969
970	if (!entry) {
971	/* must drop lock before calling dma_mapping_error */
972	put_hash_bucket(bucket, flags);
973
974	if (dma_mapping_error(dev: ref->dev, dma_addr: ref->dev_addr)) {
975	err_printk(ref->dev, NULL,
976	"device driver tries to free an "
977	"invalid DMA memory address\n");
978	} else {
979	err_printk(ref->dev, NULL,
980	"device driver tries to free DMA "
981	"memory it has not allocated [device "
982	"address=0x%016llx] [size=%llu bytes]\n",
983	ref->dev_addr, ref->size);
984	}
985	return;
986	}
987
988	if (ref->size != entry->size) {
989	err_printk(ref->dev, entry, "device driver frees "
990	"DMA memory with different size "
991	"[device address=0x%016llx] [map size=%llu bytes] "
992	"[unmap size=%llu bytes]\n",
993	ref->dev_addr, entry->size, ref->size);
994	}
995
996	if (ref->type != entry->type) {
997	err_printk(ref->dev, entry, "device driver frees "
998	"DMA memory with wrong function "
999	"[device address=0x%016llx] [size=%llu bytes] "
1000	"[mapped as %s] [unmapped as %s]\n",
1001	ref->dev_addr, ref->size,
1002	type2name[entry->type], type2name[ref->type]);
1003	} else if ((entry->type == dma_debug_coherent) &&
1004	(phys_addr(entry: ref) != phys_addr(entry))) {
1005	err_printk(ref->dev, entry, "device driver frees "
1006	"DMA memory with different CPU address "
1007	"[device address=0x%016llx] [size=%llu bytes] "
1008	"[cpu alloc address=0x%016llx] "
1009	"[cpu free address=0x%016llx]",
1010	ref->dev_addr, ref->size,
1011	phys_addr(entry),
1012	phys_addr(ref));
1013	}
1014
1015	if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1016	ref->sg_call_ents != entry->sg_call_ents) {
1017	err_printk(ref->dev, entry, "device driver frees "
1018	"DMA sg list with different entry count "
1019	"[map count=%d] [unmap count=%d]\n",
1020	entry->sg_call_ents, ref->sg_call_ents);
1021	}
1022
1023	/*
1024	* This may be no bug in reality - but most implementations of the
1025	* DMA API don't handle this properly, so check for it here
1026	*/
1027	if (ref->direction != entry->direction) {
1028	err_printk(ref->dev, entry, "device driver frees "
1029	"DMA memory with different direction "
1030	"[device address=0x%016llx] [size=%llu bytes] "
1031	"[mapped with %s] [unmapped with %s]\n",
1032	ref->dev_addr, ref->size,
1033	dir2name[entry->direction],
1034	dir2name[ref->direction]);
1035	}
1036
1037	/*
1038	* Drivers should use dma_mapping_error() to check the returned
1039	* addresses of dma_map_single() and dma_map_page().
1040	* If not, print this warning message. See Documentation/core-api/dma-api.rst.
1041	*/
1042	if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1043	err_printk(ref->dev, entry,
1044	"device driver failed to check map error"
1045	"[device address=0x%016llx] [size=%llu bytes] "
1046	"[mapped as %s]",
1047	ref->dev_addr, ref->size,
1048	type2name[entry->type]);
1049	}
1050
1051	hash_bucket_del(entry);
1052	dma_entry_free(entry);
1053
1054	put_hash_bucket(bucket, flags);
1055	}
1056
1057	static void check_for_stack(struct device *dev,
1058	struct page *page, size_t offset)
1059	{
1060	void *addr;
1061	struct vm_struct *stack_vm_area = task_stack_vm_area(current);
1062
1063	if (!stack_vm_area) {
1064	/* Stack is direct-mapped. */
1065	if (PageHighMem(page))
1066	return;
1067	addr = page_address(page) + offset;
1068	if (object_is_on_stack(obj: addr))
1069	err_printk(dev, NULL, "device driver maps memory from stack [addr=%p]\n", addr);
1070	} else {
1071	/* Stack is vmalloced. */
1072	int i;
1073
1074	for (i = 0; i < stack_vm_area->nr_pages; i++) {
1075	if (page != stack_vm_area->pages[i])
1076	continue;
1077
1078	addr = (u8 *)current->stack + i * PAGE_SIZE + offset;
1079	err_printk(dev, NULL, "device driver maps memory from stack [probable addr=%p]\n", addr);
1080	break;
1081	}
1082	}
1083	}
1084
1085	static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
1086	{
1087	if (memory_intersects(begin: _stext, end: _etext, virt: addr, size: len) ||
1088	memory_intersects(begin: __start_rodata, end: __end_rodata, virt: addr, size: len))
1089	err_printk(dev, NULL, "device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
1090	}
1091
1092	static void check_sync(struct device *dev,
1093	struct dma_debug_entry *ref,
1094	bool to_cpu)
1095	{
1096	struct dma_debug_entry *entry;
1097	struct hash_bucket *bucket;
1098	unsigned long flags;
1099
1100	bucket = get_hash_bucket(entry: ref, flags: &flags);
1101
1102	entry = bucket_find_contain(bucket: &bucket, ref, flags: &flags);
1103
1104	if (!entry) {
1105	err_printk(dev, NULL, "device driver tries "
1106	"to sync DMA memory it has not allocated "
1107	"[device address=0x%016llx] [size=%llu bytes]\n",
1108	(unsigned long long)ref->dev_addr, ref->size);
1109	goto out;
1110	}
1111
1112	if (ref->size > entry->size) {
1113	err_printk(dev, entry, "device driver syncs"
1114	" DMA memory outside allocated range "
1115	"[device address=0x%016llx] "
1116	"[allocation size=%llu bytes] "
1117	"[sync offset+size=%llu]\n",
1118	entry->dev_addr, entry->size,
1119	ref->size);
1120	}
1121
1122	if (entry->direction == DMA_BIDIRECTIONAL)
1123	goto out;
1124
1125	if (ref->direction != entry->direction) {
1126	err_printk(dev, entry, "device driver syncs "
1127	"DMA memory with different direction "
1128	"[device address=0x%016llx] [size=%llu bytes] "
1129	"[mapped with %s] [synced with %s]\n",
1130	(unsigned long long)ref->dev_addr, entry->size,
1131	dir2name[entry->direction],
1132	dir2name[ref->direction]);
1133	}
1134
1135	if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
1136	!(ref->direction == DMA_TO_DEVICE))
1137	err_printk(dev, entry, "device driver syncs "
1138	"device read-only DMA memory for cpu "
1139	"[device address=0x%016llx] [size=%llu bytes] "
1140	"[mapped with %s] [synced with %s]\n",
1141	(unsigned long long)ref->dev_addr, entry->size,
1142	dir2name[entry->direction],
1143	dir2name[ref->direction]);
1144
1145	if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
1146	!(ref->direction == DMA_FROM_DEVICE))
1147	err_printk(dev, entry, "device driver syncs "
1148	"device write-only DMA memory to device "
1149	"[device address=0x%016llx] [size=%llu bytes] "
1150	"[mapped with %s] [synced with %s]\n",
1151	(unsigned long long)ref->dev_addr, entry->size,
1152	dir2name[entry->direction],
1153	dir2name[ref->direction]);
1154
1155	if (ref->sg_call_ents && ref->type == dma_debug_sg &&
1156	ref->sg_call_ents != entry->sg_call_ents) {
1157	err_printk(ref->dev, entry, "device driver syncs "
1158	"DMA sg list with different entry count "
1159	"[map count=%d] [sync count=%d]\n",
1160	entry->sg_call_ents, ref->sg_call_ents);
1161	}
1162
1163	out:
1164	put_hash_bucket(bucket, flags);
1165	}
1166
1167	static void check_sg_segment(struct device *dev, struct scatterlist *sg)
1168	{
1169	#ifdef CONFIG_DMA_API_DEBUG_SG
1170	unsigned int max_seg = dma_get_max_seg_size(dev);
1171	u64 start, end, boundary = dma_get_seg_boundary(dev);
1172
1173	/*
1174	* Either the driver forgot to set dma_parms appropriately, or
1175	* whoever generated the list forgot to check them.
1176	*/
1177	if (sg->length > max_seg)
1178	err_printk(dev, NULL, "mapping sg segment longer than device claims to support [len=%u] [max=%u]\n",
1179	sg->length, max_seg);
1180	/*
1181	* In some cases this could potentially be the DMA API
1182	* implementation's fault, but it would usually imply that
1183	* the scatterlist was built inappropriately to begin with.
1184	*/
1185	start = sg_dma_address(sg);
1186	end = start + sg_dma_len(sg) - 1;
1187	if ((start ^ end) & ~boundary)
1188	err_printk(dev, NULL, "mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n",
1189	start, end, boundary);
1190	#endif
1191	}
1192
1193	void debug_dma_map_single(struct device *dev, const void *addr,
1194	unsigned long len)
1195	{
1196	if (unlikely(dma_debug_disabled()))
1197	return;
1198
1199	if (!virt_addr_valid(addr))
1200	err_printk(dev, NULL, "device driver maps memory from invalid area [addr=%p] [len=%lu]\n",
1201	addr, len);
1202
1203	if (is_vmalloc_addr(x: addr))
1204	err_printk(dev, NULL, "device driver maps memory from vmalloc area [addr=%p] [len=%lu]\n",
1205	addr, len);
1206	}
1207	EXPORT_SYMBOL(debug_dma_map_single);
1208
1209	void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
1210	size_t size, int direction, dma_addr_t dma_addr,
1211	unsigned long attrs)
1212	{
1213	struct dma_debug_entry *entry;
1214
1215	if (unlikely(dma_debug_disabled()))
1216	return;
1217
1218	if (dma_mapping_error(dev, dma_addr))
1219	return;
1220
1221	entry = dma_entry_alloc();
1222	if (!entry)
1223	return;
1224
1225	entry->dev = dev;
1226	entry->type = dma_debug_single;
1227	entry->pfn = page_to_pfn(page);
1228	entry->offset = offset;
1229	entry->dev_addr = dma_addr;
1230	entry->size = size;
1231	entry->direction = direction;
1232	entry->map_err_type = MAP_ERR_NOT_CHECKED;
1233
1234	check_for_stack(dev, page, offset);
1235
1236	if (!PageHighMem(page)) {
1237	void *addr = page_address(page) + offset;
1238
1239	check_for_illegal_area(dev, addr, len: size);
1240	}
1241
1242	add_dma_entry(entry, attrs);
1243	}
1244
1245	void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
1246	{
1247	struct dma_debug_entry ref;
1248	struct dma_debug_entry *entry;
1249	struct hash_bucket *bucket;
1250	unsigned long flags;
1251
1252	if (unlikely(dma_debug_disabled()))
1253	return;
1254
1255	ref.dev = dev;
1256	ref.dev_addr = dma_addr;
1257	bucket = get_hash_bucket(entry: &ref, flags: &flags);
1258
1259	list_for_each_entry(entry, &bucket->list, list) {
1260	if (!exact_match(a: &ref, b: entry))
1261	continue;
1262
1263	/*
1264	* The same physical address can be mapped multiple
1265	* times. Without a hardware IOMMU this results in the
1266	* same device addresses being put into the dma-debug
1267	* hash multiple times too. This can result in false
1268	* positives being reported. Therefore we implement a
1269	* best-fit algorithm here which updates the first entry
1270	* from the hash which fits the reference value and is
1271	* not currently listed as being checked.
1272	*/
1273	if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
1274	entry->map_err_type = MAP_ERR_CHECKED;
1275	break;
1276	}
1277	}
1278
1279	put_hash_bucket(bucket, flags);
1280	}
1281	EXPORT_SYMBOL(debug_dma_mapping_error);
1282
1283	void debug_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
1284	size_t size, int direction)
1285	{
1286	struct dma_debug_entry ref = {
1287	.type = dma_debug_single,
1288	.dev = dev,
1289	.dev_addr = dma_addr,
1290	.size = size,
1291	.direction = direction,
1292	};
1293
1294	if (unlikely(dma_debug_disabled()))
1295	return;
1296	check_unmap(ref: &ref);
1297	}
1298
1299	void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
1300	int nents, int mapped_ents, int direction,
1301	unsigned long attrs)
1302	{
1303	struct dma_debug_entry *entry;
1304	struct scatterlist *s;
1305	int i;
1306
1307	if (unlikely(dma_debug_disabled()))
1308	return;
1309
1310	for_each_sg(sg, s, nents, i) {
1311	check_for_stack(dev, page: sg_page(sg: s), offset: s->offset);
1312	if (!PageHighMem(page: sg_page(sg: s)))
1313	check_for_illegal_area(dev, addr: sg_virt(sg: s), len: s->length);
1314	}
1315
1316	for_each_sg(sg, s, mapped_ents, i) {
1317	entry = dma_entry_alloc();
1318	if (!entry)
1319	return;
1320
1321	entry->type = dma_debug_sg;
1322	entry->dev = dev;
1323	entry->pfn = page_to_pfn(sg_page(s));
1324	entry->offset = s->offset;
1325	entry->size = sg_dma_len(s);
1326	entry->dev_addr = sg_dma_address(s);
1327	entry->direction = direction;
1328	entry->sg_call_ents = nents;
1329	entry->sg_mapped_ents = mapped_ents;
1330
1331	check_sg_segment(dev, sg: s);
1332
1333	add_dma_entry(entry, attrs);
1334	}
1335	}
1336
1337	static int get_nr_mapped_entries(struct device *dev,
1338	struct dma_debug_entry *ref)
1339	{
1340	struct dma_debug_entry *entry;
1341	struct hash_bucket *bucket;
1342	unsigned long flags;
1343	int mapped_ents;
1344
1345	bucket = get_hash_bucket(entry: ref, flags: &flags);
1346	entry = bucket_find_exact(bucket, ref);
1347	mapped_ents = 0;
1348
1349	if (entry)
1350	mapped_ents = entry->sg_mapped_ents;
1351	put_hash_bucket(bucket, flags);
1352
1353	return mapped_ents;
1354	}
1355
1356	void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
1357	int nelems, int dir)
1358	{
1359	struct scatterlist *s;
1360	int mapped_ents = 0, i;
1361
1362	if (unlikely(dma_debug_disabled()))
1363	return;
1364
1365	for_each_sg(sglist, s, nelems, i) {
1366
1367	struct dma_debug_entry ref = {
1368	.type = dma_debug_sg,
1369	.dev = dev,
1370	.pfn = page_to_pfn(sg_page(s)),
1371	.offset = s->offset,
1372	.dev_addr = sg_dma_address(s),
1373	.size = sg_dma_len(s),
1374	.direction = dir,
1375	.sg_call_ents = nelems,
1376	};
1377
1378	if (mapped_ents && i >= mapped_ents)
1379	break;
1380
1381	if (!i)
1382	mapped_ents = get_nr_mapped_entries(dev, ref: &ref);
1383
1384	check_unmap(ref: &ref);
1385	}
1386	}
1387
1388	void debug_dma_alloc_coherent(struct device *dev, size_t size,
1389	dma_addr_t dma_addr, void *virt,
1390	unsigned long attrs)
1391	{
1392	struct dma_debug_entry *entry;
1393
1394	if (unlikely(dma_debug_disabled()))
1395	return;
1396
1397	if (unlikely(virt == NULL))
1398	return;
1399
1400	/* handle vmalloc and linear addresses */
1401	if (!is_vmalloc_addr(x: virt) && !virt_addr_valid(virt))
1402	return;
1403
1404	entry = dma_entry_alloc();
1405	if (!entry)
1406	return;
1407
1408	entry->type = dma_debug_coherent;
1409	entry->dev = dev;
1410	entry->offset = offset_in_page(virt);
1411	entry->size = size;
1412	entry->dev_addr = dma_addr;
1413	entry->direction = DMA_BIDIRECTIONAL;
1414
1415	if (is_vmalloc_addr(x: virt))
1416	entry->pfn = vmalloc_to_pfn(addr: virt);
1417	else
1418	entry->pfn = page_to_pfn(virt_to_page(virt));
1419
1420	add_dma_entry(entry, attrs);
1421	}
1422
1423	void debug_dma_free_coherent(struct device *dev, size_t size,
1424	void *virt, dma_addr_t dma_addr)
1425	{
1426	struct dma_debug_entry ref = {
1427	.type = dma_debug_coherent,
1428	.dev = dev,
1429	.offset = offset_in_page(virt),
1430	.dev_addr = dma_addr,
1431	.size = size,
1432	.direction = DMA_BIDIRECTIONAL,
1433	};
1434
1435	/* handle vmalloc and linear addresses */
1436	if (!is_vmalloc_addr(x: virt) && !virt_addr_valid(virt))
1437	return;
1438
1439	if (is_vmalloc_addr(x: virt))
1440	ref.pfn = vmalloc_to_pfn(addr: virt);
1441	else
1442	ref.pfn = page_to_pfn(virt_to_page(virt));
1443
1444	if (unlikely(dma_debug_disabled()))
1445	return;
1446
1447	check_unmap(ref: &ref);
1448	}
1449
1450	void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
1451	int direction, dma_addr_t dma_addr,
1452	unsigned long attrs)
1453	{
1454	struct dma_debug_entry *entry;
1455
1456	if (unlikely(dma_debug_disabled()))
1457	return;
1458
1459	entry = dma_entry_alloc();
1460	if (!entry)
1461	return;
1462
1463	entry->type = dma_debug_resource;
1464	entry->dev = dev;
1465	entry->pfn = PHYS_PFN(addr);
1466	entry->offset = offset_in_page(addr);
1467	entry->size = size;
1468	entry->dev_addr = dma_addr;
1469	entry->direction = direction;
1470	entry->map_err_type = MAP_ERR_NOT_CHECKED;
1471
1472	add_dma_entry(entry, attrs);
1473	}
1474
1475	void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
1476	size_t size, int direction)
1477	{
1478	struct dma_debug_entry ref = {
1479	.type = dma_debug_resource,
1480	.dev = dev,
1481	.dev_addr = dma_addr,
1482	.size = size,
1483	.direction = direction,
1484	};
1485
1486	if (unlikely(dma_debug_disabled()))
1487	return;
1488
1489	check_unmap(ref: &ref);
1490	}
1491
1492	void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
1493	size_t size, int direction)
1494	{
1495	struct dma_debug_entry ref;
1496
1497	if (unlikely(dma_debug_disabled()))
1498	return;
1499
1500	ref.type = dma_debug_single;
1501	ref.dev = dev;
1502	ref.dev_addr = dma_handle;
1503	ref.size = size;
1504	ref.direction = direction;
1505	ref.sg_call_ents = 0;
1506
1507	check_sync(dev, ref: &ref, to_cpu: true);
1508	}
1509
1510	void debug_dma_sync_single_for_device(struct device *dev,
1511	dma_addr_t dma_handle, size_t size,
1512	int direction)
1513	{
1514	struct dma_debug_entry ref;
1515
1516	if (unlikely(dma_debug_disabled()))
1517	return;
1518
1519	ref.type = dma_debug_single;
1520	ref.dev = dev;
1521	ref.dev_addr = dma_handle;
1522	ref.size = size;
1523	ref.direction = direction;
1524	ref.sg_call_ents = 0;
1525
1526	check_sync(dev, ref: &ref, to_cpu: false);
1527	}
1528
1529	void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1530	int nelems, int direction)
1531	{
1532	struct scatterlist *s;
1533	int mapped_ents = 0, i;
1534
1535	if (unlikely(dma_debug_disabled()))
1536	return;
1537
1538	for_each_sg(sg, s, nelems, i) {
1539
1540	struct dma_debug_entry ref = {
1541	.type = dma_debug_sg,
1542	.dev = dev,
1543	.pfn = page_to_pfn(sg_page(s)),
1544	.offset = s->offset,
1545	.dev_addr = sg_dma_address(s),
1546	.size = sg_dma_len(s),
1547	.direction = direction,
1548	.sg_call_ents = nelems,
1549	};
1550
1551	if (!i)
1552	mapped_ents = get_nr_mapped_entries(dev, ref: &ref);
1553
1554	if (i >= mapped_ents)
1555	break;
1556
1557	check_sync(dev, ref: &ref, to_cpu: true);
1558	}
1559	}
1560
1561	void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1562	int nelems, int direction)
1563	{
1564	struct scatterlist *s;
1565	int mapped_ents = 0, i;
1566
1567	if (unlikely(dma_debug_disabled()))
1568	return;
1569
1570	for_each_sg(sg, s, nelems, i) {
1571
1572	struct dma_debug_entry ref = {
1573	.type = dma_debug_sg,
1574	.dev = dev,
1575	.pfn = page_to_pfn(sg_page(s)),
1576	.offset = s->offset,
1577	.dev_addr = sg_dma_address(s),
1578	.size = sg_dma_len(s),
1579	.direction = direction,
1580	.sg_call_ents = nelems,
1581	};
1582	if (!i)
1583	mapped_ents = get_nr_mapped_entries(dev, ref: &ref);
1584
1585	if (i >= mapped_ents)
1586	break;
1587
1588	check_sync(dev, ref: &ref, to_cpu: false);
1589	}
1590	}
1591
1592	static int __init dma_debug_driver_setup(char *str)
1593	{
1594	int i;
1595
1596	for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
1597	current_driver_name[i] = *str;
1598	if (*str == 0)
1599	break;
1600	}
1601
1602	if (current_driver_name[0])
1603	pr_info("enable driver filter for driver [%s]\n",
1604	current_driver_name);
1605
1606
1607	return 1;
1608	}
1609	__setup("dma_debug_driver=", dma_debug_driver_setup);
1610