dma-mapping: move all DMA mapping code to kernel/dma

Currently the code is split over various files with dma- prefixes in the
lib/ and drives/base directories, and the number of files keeps growing.
Move them into a single directory to keep the code together and remove
the file name prefixes.  To match the irq infrastructure this directory
is placed under the kernel/ directory.

Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 0 insertions, 1773 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
deleted file mode 100644
index c007d25bee09..000000000000
--- a/lib/dma-debug.c
+++ /dev/null
@@ -1,1773 +0,0 @@
-/*
- * Copyright (C) 2008 Advanced Micro Devices, Inc.
- *
- * Author: Joerg Roedel <joerg.roedel@amd.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
- */
-
-#include <linux/sched/task_stack.h>
-#include <linux/scatterlist.h>
-#include <linux/dma-mapping.h>
-#include <linux/sched/task.h>
-#include <linux/stacktrace.h>
-#include <linux/dma-debug.h>
-#include <linux/spinlock.h>
-#include <linux/vmalloc.h>
-#include <linux/debugfs.h>
-#include <linux/uaccess.h>
-#include <linux/export.h>
-#include <linux/device.h>
-#include <linux/types.h>
-#include <linux/sched.h>
-#include <linux/ctype.h>
-#include <linux/list.h>
-#include <linux/slab.h>
-
-#include <asm/sections.h>
-
-#define HASH_SIZE       1024ULL
-#define HASH_FN_SHIFT   13
-#define HASH_FN_MASK    (HASH_SIZE - 1)
-
-/* allow architectures to override this if absolutely required */
-#ifndef PREALLOC_DMA_DEBUG_ENTRIES
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-#endif
-
-enum {
-	dma_debug_single,
-	dma_debug_page,
-	dma_debug_sg,
-	dma_debug_coherent,
-	dma_debug_resource,
-};
-
-enum map_err_types {
-	MAP_ERR_CHECK_NOT_APPLICABLE,
-	MAP_ERR_NOT_CHECKED,
-	MAP_ERR_CHECKED,
-};
-
-#define DMA_DEBUG_STACKTRACE_ENTRIES 5
-
-/**
- * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
- * @list: node on pre-allocated free_entries list
- * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
- * @type: single, page, sg, coherent
- * @pfn: page frame of the start address
- * @offset: offset of mapping relative to pfn
- * @size: length of the mapping
- * @direction: enum dma_data_direction
- * @sg_call_ents: 'nents' from dma_map_sg
- * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
- * @map_err_type: track whether dma_mapping_error() was checked
- * @stacktrace: support backtraces when a violation is detected
- */
-struct dma_debug_entry {
-	struct list_head list;
-	struct device    *dev;
-	int              type;
-	unsigned long	 pfn;
-	size_t		 offset;
-	u64              dev_addr;
-	u64              size;
-	int              direction;
-	int		 sg_call_ents;
-	int		 sg_mapped_ents;
-	enum map_err_types  map_err_type;
-#ifdef CONFIG_STACKTRACE
-	struct		 stack_trace stacktrace;
-	unsigned long	 st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
-#endif
-};
-
-typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);
-
-struct hash_bucket {
-	struct list_head list;
-	spinlock_t lock;
-} ____cacheline_aligned_in_smp;
-
-/* Hash list to save the allocated dma addresses */
-static struct hash_bucket dma_entry_hash[HASH_SIZE];
-/* List of pre-allocated dma_debug_entry's */
-static LIST_HEAD(free_entries);
-/* Lock for the list above */
-static DEFINE_SPINLOCK(free_entries_lock);
-
-/* Global disable flag - will be set in case of an error */
-static bool global_disable __read_mostly;
-
-/* Early initialization disable flag, set at the end of dma_debug_init */
-static bool dma_debug_initialized __read_mostly;
-
-static inline bool dma_debug_disabled(void)
-{
-	return global_disable || !dma_debug_initialized;
-}
-
-/* Global error count */
-static u32 error_count;
-
-/* Global error show enable*/
-static u32 show_all_errors __read_mostly;
-/* Number of errors to show */
-static u32 show_num_errors = 1;
-
-static u32 num_free_entries;
-static u32 min_free_entries;
-static u32 nr_total_entries;
-
-/* number of preallocated entries requested by kernel cmdline */
-static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
-
-/* debugfs dentry's for the stuff above */
-static struct dentry *dma_debug_dent        __read_mostly;
-static struct dentry *global_disable_dent   __read_mostly;
-static struct dentry *error_count_dent      __read_mostly;
-static struct dentry *show_all_errors_dent  __read_mostly;
-static struct dentry *show_num_errors_dent  __read_mostly;
-static struct dentry *num_free_entries_dent __read_mostly;
-static struct dentry *min_free_entries_dent __read_mostly;
-static struct dentry *filter_dent           __read_mostly;
-
-/* per-driver filter related state */
-
-#define NAME_MAX_LEN	64
-
-static char                  current_driver_name[NAME_MAX_LEN] __read_mostly;
-static struct device_driver *current_driver                    __read_mostly;
-
-static DEFINE_RWLOCK(driver_name_lock);
-
-static const char *const maperr2str[] = {
-	[MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
-	[MAP_ERR_NOT_CHECKED] = "dma map error not checked",
-	[MAP_ERR_CHECKED] = "dma map error checked",
-};
-
-static const char *type2name[5] = { "single", "page",
-				    "scather-gather", "coherent",
-				    "resource" };
-
-static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
-				   "DMA_FROM_DEVICE", "DMA_NONE" };
-
-/*
- * The access to some variables in this macro is racy. We can't use atomic_t
- * here because all these variables are exported to debugfs. Some of them even
- * writeable. This is also the reason why a lock won't help much. But anyway,
- * the races are no big deal. Here is why:
- *
- *   error_count: the addition is racy, but the worst thing that can happen is
- *                that we don't count some errors
- *   show_num_errors: the subtraction is racy. Also no big deal because in
- *                    worst case this will result in one warning more in the
- *                    system log than the user configured. This variable is
- *                    writeable via debugfs.
- */
-static inline void dump_entry_trace(struct dma_debug_entry *entry)
-{
-#ifdef CONFIG_STACKTRACE
-	if (entry) {
-		pr_warning("Mapped at:\n");
-		print_stack_trace(&entry->stacktrace, 0);
-	}
-#endif
-}
-
-static bool driver_filter(struct device *dev)
-{
-	struct device_driver *drv;
-	unsigned long flags;
-	bool ret;
-
-	/* driver filter off */
-	if (likely(!current_driver_name[0]))
-		return true;
-
-	/* driver filter on and initialized */
-	if (current_driver && dev && dev->driver == current_driver)
-		return true;
-
-	/* driver filter on, but we can't filter on a NULL device... */
-	if (!dev)
-		return false;
-
-	if (current_driver || !current_driver_name[0])
-		return false;
-
-	/* driver filter on but not yet initialized */
-	drv = dev->driver;
-	if (!drv)
-		return false;
-
-	/* lock to protect against change of current_driver_name */
-	read_lock_irqsave(&driver_name_lock, flags);
-
-	ret = false;
-	if (drv->name &&
-	    strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
-		current_driver = drv;
-		ret = true;
-	}
-
-	read_unlock_irqrestore(&driver_name_lock, flags);
-
-	return ret;
-}
-
-#define err_printk(dev, entry, format, arg...) do {			\
-		error_count += 1;					\
-		if (driver_filter(dev) &&				\
-		    (show_all_errors || show_num_errors > 0)) {		\
-			WARN(1, "%s %s: " format,			\
-			     dev ? dev_driver_string(dev) : "NULL",	\
-			     dev ? dev_name(dev) : "NULL", ## arg);	\
-			dump_entry_trace(entry);			\
-		}							\
-		if (!show_all_errors && show_num_errors > 0)		\
-			show_num_errors -= 1;				\
-	} while (0);
-
-/*
- * Hash related functions
- *
- * Every DMA-API request is saved into a struct dma_debug_entry. To
- * have quick access to these structs they are stored into a hash.
- */
-static int hash_fn(struct dma_debug_entry *entry)
-{
-	/*
-	 * Hash function is based on the dma address.
-	 * We use bits 20-27 here as the index into the hash
-	 */
-	return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
-}
-
-/*
- * Request exclusive access to a hash bucket for a given dma_debug_entry.
- */
-static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
-					   unsigned long *flags)
-	__acquires(&dma_entry_hash[idx].lock)
-{
-	int idx = hash_fn(entry);
-	unsigned long __flags;
-
-	spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
-	*flags = __flags;
-	return &dma_entry_hash[idx];
-}
-
-/*
- * Give up exclusive access to the hash bucket
- */
-static void put_hash_bucket(struct hash_bucket *bucket,
-			    unsigned long *flags)
-	__releases(&bucket->lock)
-{
-	unsigned long __flags = *flags;
-
-	spin_unlock_irqrestore(&bucket->lock, __flags);
-}
-
-static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
-{
-	return ((a->dev_addr == b->dev_addr) &&
-		(a->dev == b->dev)) ? true : false;
-}
-
-static bool containing_match(struct dma_debug_entry *a,
-			     struct dma_debug_entry *b)
-{
-	if (a->dev != b->dev)
-		return false;
-
-	if ((b->dev_addr <= a->dev_addr) &&
-	    ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
-		return true;
-
-	return false;
-}
-
-/*
- * Search a given entry in the hash bucket list
- */
-static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
-						  struct dma_debug_entry *ref,
-						  match_fn match)
-{
-	struct dma_debug_entry *entry, *ret = NULL;
-	int matches = 0, match_lvl, last_lvl = -1;
-
-	list_for_each_entry(entry, &bucket->list, list) {
-		if (!match(ref, entry))
-			continue;
-
-		/*
-		 * Some drivers map the same physical address multiple
-		 * times. Without a hardware IOMMU this results in the
-		 * same device addresses being put into the dma-debug
-		 * hash multiple times too. This can result in false
-		 * positives being reported. Therefore we implement a
-		 * best-fit algorithm here which returns the entry from
-		 * the hash which fits best to the reference value
-		 * instead of the first-fit.
-		 */
-		matches += 1;
-		match_lvl = 0;
-		entry->size         == ref->size         ? ++match_lvl : 0;
-		entry->type         == ref->type         ? ++match_lvl : 0;
-		entry->direction    == ref->direction    ? ++match_lvl : 0;
-		entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;
-
-		if (match_lvl == 4) {
-			/* perfect-fit - return the result */
-			return entry;
-		} else if (match_lvl > last_lvl) {
-			/*
-			 * We found an entry that fits better then the
-			 * previous one or it is the 1st match.
-			 */
-			last_lvl = match_lvl;
-			ret      = entry;
-		}
-	}
-
-	/*
-	 * If we have multiple matches but no perfect-fit, just return
-	 * NULL.
-	 */
-	ret = (matches == 1) ? ret : NULL;
-
-	return ret;
-}
-
-static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
-						 struct dma_debug_entry *ref)
-{
-	return __hash_bucket_find(bucket, ref, exact_match);
-}
-
-static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
-						   struct dma_debug_entry *ref,
-						   unsigned long *flags)
-{
-
-	unsigned int max_range = dma_get_max_seg_size(ref->dev);
-	struct dma_debug_entry *entry, index = *ref;
-	unsigned int range = 0;
-
-	while (range <= max_range) {
-		entry = __hash_bucket_find(*bucket, ref, containing_match);
-
-		if (entry)
-			return entry;
-
-		/*
-		 * Nothing found, go back a hash bucket
-		 */
-		put_hash_bucket(*bucket, flags);
-		range          += (1 << HASH_FN_SHIFT);
-		index.dev_addr -= (1 << HASH_FN_SHIFT);
-		*bucket = get_hash_bucket(&index, flags);
-	}
-
-	return NULL;
-}
-
-/*
- * Add an entry to a hash bucket
- */
-static void hash_bucket_add(struct hash_bucket *bucket,
-			    struct dma_debug_entry *entry)
-{
-	list_add_tail(&entry->list, &bucket->list);
-}
-
-/*
- * Remove entry from a hash bucket list
- */
-static void hash_bucket_del(struct dma_debug_entry *entry)
-{
-	list_del(&entry->list);
-}
-
-static unsigned long long phys_addr(struct dma_debug_entry *entry)
-{
-	if (entry->type == dma_debug_resource)
-		return __pfn_to_phys(entry->pfn) + entry->offset;
-
-	return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
-}
-
-/*
- * Dump mapping entries for debugging purposes
- */
-void debug_dma_dump_mappings(struct device *dev)
-{
-	int idx;
-
-	for (idx = 0; idx < HASH_SIZE; idx++) {
-		struct hash_bucket *bucket = &dma_entry_hash[idx];
-		struct dma_debug_entry *entry;
-		unsigned long flags;
-
-		spin_lock_irqsave(&bucket->lock, flags);
-
-		list_for_each_entry(entry, &bucket->list, list) {
-			if (!dev || dev == entry->dev) {
-				dev_info(entry->dev,
-					 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
-					 type2name[entry->type], idx,
-					 phys_addr(entry), entry->pfn,
-					 entry->dev_addr, entry->size,
-					 dir2name[entry->direction],
-					 maperr2str[entry->map_err_type]);
-			}
-		}
-
-		spin_unlock_irqrestore(&bucket->lock, flags);
-	}
-}
-
-/*
- * For each mapping (initial cacheline in the case of
- * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
- * scatterlist, or the cacheline specified in dma_map_single) insert
- * into this tree using the cacheline as the key. At
- * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry.  If
- * the entry already exists at insertion time add a tag as a reference
- * count for the overlapping mappings.  For now, the overlap tracking
- * just ensures that 'unmaps' balance 'maps' before marking the
- * cacheline idle, but we should also be flagging overlaps as an API
- * violation.
- *
- * Memory usage is mostly constrained by the maximum number of available
- * dma-debug entries in that we need a free dma_debug_entry before
- * inserting into the tree.  In the case of dma_map_page and
- * dma_alloc_coherent there is only one dma_debug_entry and one
- * dma_active_cacheline entry to track per event.  dma_map_sg(), on the
- * other hand, consumes a single dma_debug_entry, but inserts 'nents'
- * entries into the tree.
- *
- * At any time debug_dma_assert_idle() can be called to trigger a
- * warning if any cachelines in the given page are in the active set.
- */
-static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
-static DEFINE_SPINLOCK(radix_lock);
-#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
-#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
-#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
-
-static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
-{
-	return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
-		(entry->offset >> L1_CACHE_SHIFT);
-}
-
-static int active_cacheline_read_overlap(phys_addr_t cln)
-{
-	int overlap = 0, i;
-
-	for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
-		if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
-			overlap |= 1 << i;
-	return overlap;
-}
-
-static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
-{
-	int i;
-
-	if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
-		return overlap;
-
-	for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
-		if (overlap & 1 << i)
-			radix_tree_tag_set(&dma_active_cacheline, cln, i);
-		else
-			radix_tree_tag_clear(&dma_active_cacheline, cln, i);
-
-	return overlap;
-}
-
-static void active_cacheline_inc_overlap(phys_addr_t cln)
-{
-	int overlap = active_cacheline_read_overlap(cln);
-
-	overlap = active_cacheline_set_overlap(cln, ++overlap);
-
-	/* If we overflowed the overlap counter then we're potentially
-	 * leaking dma-mappings.  Otherwise, if maps and unmaps are
-	 * balanced then this overflow may cause false negatives in
-	 * debug_dma_assert_idle() as the cacheline may be marked idle
-	 * prematurely.
-	 */
-	WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
-		  "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
-		  ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
-}
-
-static int active_cacheline_dec_overlap(phys_addr_t cln)
-{
-	int overlap = active_cacheline_read_overlap(cln);
-
-	return active_cacheline_set_overlap(cln, --overlap);
-}
-
-static int active_cacheline_insert(struct dma_debug_entry *entry)
-{
-	phys_addr_t cln = to_cacheline_number(entry);
-	unsigned long flags;
-	int rc;
-
-	/* If the device is not writing memory then we don't have any
-	 * concerns about the cpu consuming stale data.  This mitigates
-	 * legitimate usages of overlapping mappings.
-	 */
-	if (entry->direction == DMA_TO_DEVICE)
-		return 0;
-
-	spin_lock_irqsave(&radix_lock, flags);
-	rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
-	if (rc == -EEXIST)
-		active_cacheline_inc_overlap(cln);
-	spin_unlock_irqrestore(&radix_lock, flags);
-
-	return rc;
-}
-
-static void active_cacheline_remove(struct dma_debug_entry *entry)
-{
-	phys_addr_t cln = to_cacheline_number(entry);
-	unsigned long flags;
-
-	/* ...mirror the insert case */
-	if (entry->direction == DMA_TO_DEVICE)
-		return;
-
-	spin_lock_irqsave(&radix_lock, flags);
-	/* since we are counting overlaps the final put of the
-	 * cacheline will occur when the overlap count is 0.
-	 * active_cacheline_dec_overlap() returns -1 in that case
-	 */
-	if (active_cacheline_dec_overlap(cln) < 0)
-		radix_tree_delete(&dma_active_cacheline, cln);
-	spin_unlock_irqrestore(&radix_lock, flags);
-}
-
-/**
- * debug_dma_assert_idle() - assert that a page is not undergoing dma
- * @page: page to lookup in the dma_active_cacheline tree
- *
- * Place a call to this routine in cases where the cpu touching the page
- * before the dma completes (page is dma_unmapped) will lead to data
- * corruption.
- */
-void debug_dma_assert_idle(struct page *page)
-{
-	static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
-	struct dma_debug_entry *entry = NULL;
-	void **results = (void **) &ents;
-	unsigned int nents, i;
-	unsigned long flags;
-	phys_addr_t cln;
-
-	if (dma_debug_disabled())
-		return;
-
-	if (!page)
-		return;
-
-	cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
-	spin_lock_irqsave(&radix_lock, flags);
-	nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
-				       CACHELINES_PER_PAGE);
-	for (i = 0; i < nents; i++) {
-		phys_addr_t ent_cln = to_cacheline_number(ents[i]);
-
-		if (ent_cln == cln) {
-			entry = ents[i];
-			break;
-		} else if (ent_cln >= cln + CACHELINES_PER_PAGE)
-			break;
-	}
-	spin_unlock_irqrestore(&radix_lock, flags);
-
-	if (!entry)
-		return;
-
-	cln = to_cacheline_number(entry);
-	err_printk(entry->dev, entry,
-		   "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
-		   &cln);
-}
-
-/*
- * Wrapper function for adding an entry to the hash.
- * This function takes care of locking itself.
- */
-static void add_dma_entry(struct dma_debug_entry *entry)
-{
-	struct hash_bucket *bucket;
-	unsigned long flags;
-	int rc;
-
-	bucket = get_hash_bucket(entry, &flags);
-	hash_bucket_add(bucket, entry);
-	put_hash_bucket(bucket, &flags);
-
-	rc = active_cacheline_insert(entry);
-	if (rc == -ENOMEM) {
-		pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
-		global_disable = true;
-	}
-
-	/* TODO: report -EEXIST errors here as overlapping mappings are
-	 * not supported by the DMA API
-	 */
-}
-
-static struct dma_debug_entry *__dma_entry_alloc(void)
-{
-	struct dma_debug_entry *entry;
-
-	entry = list_entry(free_entries.next, struct dma_debug_entry, list);
-	list_del(&entry->list);
-	memset(entry, 0, sizeof(*entry));
-
-	num_free_entries -= 1;
-	if (num_free_entries < min_free_entries)
-		min_free_entries = num_free_entries;
-
-	return entry;
-}
-
-/* struct dma_entry allocator
- *
- * The next two functions implement the allocator for
- * struct dma_debug_entries.
- */
-static struct dma_debug_entry *dma_entry_alloc(void)
-{
-	struct dma_debug_entry *entry;
-	unsigned long flags;
-
-	spin_lock_irqsave(&free_entries_lock, flags);
-
-	if (list_empty(&free_entries)) {
-		global_disable = true;
-		spin_unlock_irqrestore(&free_entries_lock, flags);
-		pr_err("DMA-API: debugging out of memory - disabling\n");
-		return NULL;
-	}
-
-	entry = __dma_entry_alloc();
-
-	spin_unlock_irqrestore(&free_entries_lock, flags);
-
-#ifdef CONFIG_STACKTRACE
-	entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
-	entry->stacktrace.entries = entry->st_entries;
-	entry->stacktrace.skip = 2;
-	save_stack_trace(&entry->stacktrace);
-#endif
-
-	return entry;
-}
-
-static void dma_entry_free(struct dma_debug_entry *entry)
-{
-	unsigned long flags;
-
-	active_cacheline_remove(entry);
-
-	/*
-	 * add to beginning of the list - this way the entries are
-	 * more likely cache hot when they are reallocated.
-	 */
-	spin_lock_irqsave(&free_entries_lock, flags);
-	list_add(&entry->list, &free_entries);
-	num_free_entries += 1;
-	spin_unlock_irqrestore(&free_entries_lock, flags);
-}
-
-int dma_debug_resize_entries(u32 num_entries)
-{
-	int i, delta, ret = 0;
-	unsigned long flags;
-	struct dma_debug_entry *entry;
-	LIST_HEAD(tmp);
-
-	spin_lock_irqsave(&free_entries_lock, flags);
-
-	if (nr_total_entries < num_entries) {
-		delta = num_entries - nr_total_entries;
-
-		spin_unlock_irqrestore(&free_entries_lock, flags);
-
-		for (i = 0; i < delta; i++) {
-			entry = kzalloc(sizeof(*entry), GFP_KERNEL);
-			if (!entry)
-				break;
-
-			list_add_tail(&entry->list, &tmp);
-		}
-
-		spin_lock_irqsave(&free_entries_lock, flags);
-
-		list_splice(&tmp, &free_entries);
-		nr_total_entries += i;
-		num_free_entries += i;
-	} else {
-		delta = nr_total_entries - num_entries;
-
-		for (i = 0; i < delta && !list_empty(&free_entries); i++) {
-			entry = __dma_entry_alloc();
-			kfree(entry);
-		}
-
-		nr_total_entries -= i;
-	}
-
-	if (nr_total_entries != num_entries)
-		ret = 1;
-
-	spin_unlock_irqrestore(&free_entries_lock, flags);
-
-	return ret;
-}
-
-/*
- * DMA-API debugging init code
- *
- * The init code does two things:
- *   1. Initialize core data structures
- *   2. Preallocate a given number of dma_debug_entry structs
- */
-
-static int prealloc_memory(u32 num_entries)
-{
-	struct dma_debug_entry *entry, *next_entry;
-	int i;
-
-	for (i = 0; i < num_entries; ++i) {
-		entry = kzalloc(sizeof(*entry), GFP_KERNEL);
-		if (!entry)
-			goto out_err;
-
-		list_add_tail(&entry->list, &free_entries);
-	}
-
-	num_free_entries = num_entries;
-	min_free_entries = num_entries;
-
-	pr_info("DMA-API: preallocated %d debug entries\n", num_entries);
-
-	return 0;
-
-out_err:
-
-	list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
-		list_del(&entry->list);
-		kfree(entry);
-	}
-
-	return -ENOMEM;
-}
-
-static ssize_t filter_read(struct file *file, char __user *user_buf,
-			   size_t count, loff_t *ppos)
-{
-	char buf[NAME_MAX_LEN + 1];
-	unsigned long flags;
-	int len;
-
-	if (!current_driver_name[0])
-		return 0;
-
-	/*
-	 * We can't copy to userspace directly because current_driver_name can
-	 * only be read under the driver_name_lock with irqs disabled. So
-	 * create a temporary copy first.
-	 */
-	read_lock_irqsave(&driver_name_lock, flags);
-	len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
-	read_unlock_irqrestore(&driver_name_lock, flags);
-
-	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
-}
-
-static ssize_t filter_write(struct file *file, const char __user *userbuf,
-			    size_t count, loff_t *ppos)
-{
-	char buf[NAME_MAX_LEN];
-	unsigned long flags;
-	size_t len;
-	int i;
-
-	/*
-	 * We can't copy from userspace directly. Access to
-	 * current_driver_name is protected with a write_lock with irqs
-	 * disabled. Since copy_from_user can fault and may sleep we
-	 * need to copy to temporary buffer first
-	 */
-	len = min(count, (size_t)(NAME_MAX_LEN - 1));
-	if (copy_from_user(buf, userbuf, len))
-		return -EFAULT;
-
-	buf[len] = 0;
-
-	write_lock_irqsave(&driver_name_lock, flags);
-
-	/*
-	 * Now handle the string we got from userspace very carefully.
-	 * The rules are:
-	 *         - only use the first token we got
-	 *         - token delimiter is everything looking like a space
-	 *           character (' ', '\n', '\t' ...)
-	 *
-	 */
-	if (!isalnum(buf[0])) {
-		/*
-		 * If the first character userspace gave us is not
-		 * alphanumerical then assume the filter should be
-		 * switched off.
-		 */
-		if (current_driver_name[0])
-			pr_info("DMA-API: switching off dma-debug driver filter\n");
-		current_driver_name[0] = 0;
-		current_driver = NULL;
-		goto out_unlock;
-	}
-
-	/*
-	 * Now parse out the first token and use it as the name for the
-	 * driver to filter for.
-	 */
-	for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
-		current_driver_name[i] = buf[i];
-		if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
-			break;
-	}
-	current_driver_name[i] = 0;
-	current_driver = NULL;
-
-	pr_info("DMA-API: enable driver filter for driver [%s]\n",
-		current_driver_name);
-
-out_unlock:
-	write_unlock_irqrestore(&driver_name_lock, flags);
-
-	return count;
-}
-
-static const struct file_operations filter_fops = {
-	.read  = filter_read,
-	.write = filter_write,
-	.llseek = default_llseek,
-};
-
-static int dma_debug_fs_init(void)
-{
-	dma_debug_dent = debugfs_create_dir("dma-api", NULL);
-	if (!dma_debug_dent) {
-		pr_err("DMA-API: can not create debugfs directory\n");
-		return -ENOMEM;
-	}
-
-	global_disable_dent = debugfs_create_bool("disabled", 0444,
-			dma_debug_dent,
-			&global_disable);
-	if (!global_disable_dent)
-		goto out_err;
-
-	error_count_dent = debugfs_create_u32("error_count", 0444,
-			dma_debug_dent, &error_count);
-	if (!error_count_dent)
-		goto out_err;
-
-	show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
-			dma_debug_dent,
-			&show_all_errors);
-	if (!show_all_errors_dent)
-		goto out_err;
-
-	show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
-			dma_debug_dent,
-			&show_num_errors);
-	if (!show_num_errors_dent)
-		goto out_err;
-
-	num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
-			dma_debug_dent,
-			&num_free_entries);
-	if (!num_free_entries_dent)
-		goto out_err;
-
-	min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
-			dma_debug_dent,
-			&min_free_entries);
-	if (!min_free_entries_dent)
-		goto out_err;
-
-	filter_dent = debugfs_create_file("driver_filter", 0644,
-					  dma_debug_dent, NULL, &filter_fops);
-	if (!filter_dent)
-		goto out_err;
-
-	return 0;
-
-out_err:
-	debugfs_remove_recursive(dma_debug_dent);
-
-	return -ENOMEM;
-}
-
-static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
-{
-	struct dma_debug_entry *entry;
-	unsigned long flags;
-	int count = 0, i;
-
-	for (i = 0; i < HASH_SIZE; ++i) {
-		spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
-		list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
-			if (entry->dev == dev) {
-				count += 1;
-				*out_entry = entry;
-			}
-		}
-		spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
-	}
-
-	return count;
-}
-
-static int dma_debug_device_change(struct notifier_block *nb, unsigned long action, void *data)
-{
-	struct device *dev = data;
-	struct dma_debug_entry *uninitialized_var(entry);
-	int count;
-
-	if (dma_debug_disabled())
-		return 0;
-
-	switch (action) {
-	case BUS_NOTIFY_UNBOUND_DRIVER:
-		count = device_dma_allocations(dev, &entry);
-		if (count == 0)
-			break;
-		err_printk(dev, entry, "DMA-API: device driver has pending "
-				"DMA allocations while released from device "
-				"[count=%d]\n"
-				"One of leaked entries details: "
-				"[device address=0x%016llx] [size=%llu bytes] "
-				"[mapped with %s] [mapped as %s]\n",
-			count, entry->dev_addr, entry->size,
-			dir2name[entry->direction], type2name[entry->type]);
-		break;
-	default:
-		break;
-	}
-
-	return 0;
-}
-
-void dma_debug_add_bus(struct bus_type *bus)
-{
-	struct notifier_block *nb;
-
-	if (dma_debug_disabled())
-		return;
-
-	nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
-	if (nb == NULL) {
-		pr_err("dma_debug_add_bus: out of memory\n");
-		return;
-	}
-
-	nb->notifier_call = dma_debug_device_change;
-
-	bus_register_notifier(bus, nb);
-}
-
-static int dma_debug_init(void)
-{
-	int i;
-
-	/* Do not use dma_debug_initialized here, since we really want to be
-	 * called to set dma_debug_initialized
-	 */
-	if (global_disable)
-		return 0;
-
-	for (i = 0; i < HASH_SIZE; ++i) {
-		INIT_LIST_HEAD(&dma_entry_hash[i].list);
-		spin_lock_init(&dma_entry_hash[i].lock);
-	}
-
-	if (dma_debug_fs_init() != 0) {
-		pr_err("DMA-API: error creating debugfs entries - disabling\n");
-		global_disable = true;
-
-		return 0;
-	}
-
-	if (prealloc_memory(nr_prealloc_entries) != 0) {
-		pr_err("DMA-API: debugging out of memory error - disabled\n");
-		global_disable = true;
-
-		return 0;
-	}
-
-	nr_total_entries = num_free_entries;
-
-	dma_debug_initialized = true;
-
-	pr_info("DMA-API: debugging enabled by kernel config\n");
-	return 0;
-}
-core_initcall(dma_debug_init);
-
-static __init int dma_debug_cmdline(char *str)
-{
-	if (!str)
-		return -EINVAL;
-
-	if (strncmp(str, "off", 3) == 0) {
-		pr_info("DMA-API: debugging disabled on kernel command line\n");
-		global_disable = true;
-	}
-
-	return 0;
-}
-
-static __init int dma_debug_entries_cmdline(char *str)
-{
-	if (!str)
-		return -EINVAL;
-	if (!get_option(&str, &nr_prealloc_entries))
-		nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
-	return 0;
-}
-
-__setup("dma_debug=", dma_debug_cmdline);
-__setup("dma_debug_entries=", dma_debug_entries_cmdline);
-
-static void check_unmap(struct dma_debug_entry *ref)
-{
-	struct dma_debug_entry *entry;
-	struct hash_bucket *bucket;
-	unsigned long flags;
-
-	bucket = get_hash_bucket(ref, &flags);
-	entry = bucket_find_exact(bucket, ref);
-
-	if (!entry) {
-		/* must drop lock before calling dma_mapping_error */
-		put_hash_bucket(bucket, &flags);
-
-		if (dma_mapping_error(ref->dev, ref->dev_addr)) {
-			err_printk(ref->dev, NULL,
-				   "DMA-API: device driver tries to free an "
-				   "invalid DMA memory address\n");
-		} else {
-			err_printk(ref->dev, NULL,
-				   "DMA-API: device driver tries to free DMA "
-				   "memory it has not allocated [device "
-				   "address=0x%016llx] [size=%llu bytes]\n",
-				   ref->dev_addr, ref->size);
-		}
-		return;
-	}
-
-	if (ref->size != entry->size) {
-		err_printk(ref->dev, entry, "DMA-API: device driver frees "
-			   "DMA memory with different size "
-			   "[device address=0x%016llx] [map size=%llu bytes] "
-			   "[unmap size=%llu bytes]\n",
-			   ref->dev_addr, entry->size, ref->size);
-	}
-
-	if (ref->type != entry->type) {
-		err_printk(ref->dev, entry, "DMA-API: device driver frees "
-			   "DMA memory with wrong function "
-			   "[device address=0x%016llx] [size=%llu bytes] "
-			   "[mapped as %s] [unmapped as %s]\n",
-			   ref->dev_addr, ref->size,
-			   type2name[entry->type], type2name[ref->type]);
-	} else if ((entry->type == dma_debug_coherent) &&
-		   (phys_addr(ref) != phys_addr(entry))) {
-		err_printk(ref->dev, entry, "DMA-API: device driver frees "
-			   "DMA memory with different CPU address "
-			   "[device address=0x%016llx] [size=%llu bytes] "
-			   "[cpu alloc address=0x%016llx] "
-			   "[cpu free address=0x%016llx]",
-			   ref->dev_addr, ref->size,
-			   phys_addr(entry),
-			   phys_addr(ref));
-	}
-
-	if (ref->sg_call_ents && ref->type == dma_debug_sg &&
-	    ref->sg_call_ents != entry->sg_call_ents) {
-		err_printk(ref->dev, entry, "DMA-API: device driver frees "
-			   "DMA sg list with different entry count "
-			   "[map count=%d] [unmap count=%d]\n",
-			   entry->sg_call_ents, ref->sg_call_ents);
-	}
-
-	/*
-	 * This may be no bug in reality - but most implementations of the
-	 * DMA API don't handle this properly, so check for it here
-	 */
-	if (ref->direction != entry->direction) {
-		err_printk(ref->dev, entry, "DMA-API: device driver frees "
-			   "DMA memory with different direction "
-			   "[device address=0x%016llx] [size=%llu bytes] "
-			   "[mapped with %s] [unmapped with %s]\n",
-			   ref->dev_addr, ref->size,
-			   dir2name[entry->direction],
-			   dir2name[ref->direction]);
-	}
-
-	/*
-	 * Drivers should use dma_mapping_error() to check the returned
-	 * addresses of dma_map_single() and dma_map_page().
-	 * If not, print this warning message. See Documentation/DMA-API.txt.
-	 */
-	if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
-		err_printk(ref->dev, entry,
-			   "DMA-API: device driver failed to check map error"
-			   "[device address=0x%016llx] [size=%llu bytes] "
-			   "[mapped as %s]",
-			   ref->dev_addr, ref->size,
-			   type2name[entry->type]);
-	}
-
-	hash_bucket_del(entry);
-	dma_entry_free(entry);
-
-	put_hash_bucket(bucket, &flags);
-}
-
-static void check_for_stack(struct device *dev,
-			    struct page *page, size_t offset)
-{
-	void *addr;
-	struct vm_struct *stack_vm_area = task_stack_vm_area(current);
-
-	if (!stack_vm_area) {
-		/* Stack is direct-mapped. */
-		if (PageHighMem(page))
-			return;
-		addr = page_address(page) + offset;
-		if (object_is_on_stack(addr))
-			err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [addr=%p]\n", addr);
-	} else {
-		/* Stack is vmalloced. */
-		int i;
-
-		for (i = 0; i < stack_vm_area->nr_pages; i++) {
-			if (page != stack_vm_area->pages[i])
-				continue;
-
-			addr = (u8 *)current->stack + i * PAGE_SIZE + offset;
-			err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [probable addr=%p]\n", addr);
-			break;
-		}
-	}
-}
-
-static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
-{
-	unsigned long a1 = (unsigned long)addr;
-	unsigned long b1 = a1 + len;
-	unsigned long a2 = (unsigned long)start;
-	unsigned long b2 = (unsigned long)end;
-
-	return !(b1 <= a2 || a1 >= b2);
-}
-
-static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
-{
-	if (overlap(addr, len, _stext, _etext) ||
-	    overlap(addr, len, __start_rodata, __end_rodata))
-		err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
-}
-
-static void check_sync(struct device *dev,
-		       struct dma_debug_entry *ref,
-		       bool to_cpu)
-{
-	struct dma_debug_entry *entry;
-	struct hash_bucket *bucket;
-	unsigned long flags;
-
-	bucket = get_hash_bucket(ref, &flags);
-
-	entry = bucket_find_contain(&bucket, ref, &flags);
-
-	if (!entry) {
-		err_printk(dev, NULL, "DMA-API: device driver tries "
-				"to sync DMA memory it has not allocated "
-				"[device address=0x%016llx] [size=%llu bytes]\n",
-				(unsigned long long)ref->dev_addr, ref->size);
-		goto out;
-	}
-
-	if (ref->size > entry->size) {
-		err_printk(dev, entry, "DMA-API: device driver syncs"
-				" DMA memory outside allocated range "
-				"[device address=0x%016llx] "
-				"[allocation size=%llu bytes] "
-				"[sync offset+size=%llu]\n",
-				entry->dev_addr, entry->size,
-				ref->size);
-	}
-
-	if (entry->direction == DMA_BIDIRECTIONAL)
-		goto out;
-
-	if (ref->direction != entry->direction) {
-		err_printk(dev, entry, "DMA-API: device driver syncs "
-				"DMA memory with different direction "
-				"[device address=0x%016llx] [size=%llu bytes] "
-				"[mapped with %s] [synced with %s]\n",
-				(unsigned long long)ref->dev_addr, entry->size,
-				dir2name[entry->direction],
-				dir2name[ref->direction]);
-	}
-
-	if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
-		      !(ref->direction == DMA_TO_DEVICE))
-		err_printk(dev, entry, "DMA-API: device driver syncs "
-				"device read-only DMA memory for cpu "
-				"[device address=0x%016llx] [size=%llu bytes] "
-				"[mapped with %s] [synced with %s]\n",
-				(unsigned long long)ref->dev_addr, entry->size,
-				dir2name[entry->direction],
-				dir2name[ref->direction]);
-
-	if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
-		       !(ref->direction == DMA_FROM_DEVICE))
-		err_printk(dev, entry, "DMA-API: device driver syncs "
-				"device write-only DMA memory to device "
-				"[device address=0x%016llx] [size=%llu bytes] "
-				"[mapped with %s] [synced with %s]\n",
-				(unsigned long long)ref->dev_addr, entry->size,
-				dir2name[entry->direction],
-				dir2name[ref->direction]);
-
-	if (ref->sg_call_ents && ref->type == dma_debug_sg &&
-	    ref->sg_call_ents != entry->sg_call_ents) {
-		err_printk(ref->dev, entry, "DMA-API: device driver syncs "
-			   "DMA sg list with different entry count "
-			   "[map count=%d] [sync count=%d]\n",
-			   entry->sg_call_ents, ref->sg_call_ents);
-	}
-
-out:
-	put_hash_bucket(bucket, &flags);
-}
-
-static void check_sg_segment(struct device *dev, struct scatterlist *sg)
-{
-#ifdef CONFIG_DMA_API_DEBUG_SG
-	unsigned int max_seg = dma_get_max_seg_size(dev);
-	u64 start, end, boundary = dma_get_seg_boundary(dev);
-
-	/*
-	 * Either the driver forgot to set dma_parms appropriately, or
-	 * whoever generated the list forgot to check them.
-	 */
-	if (sg->length > max_seg)
-		err_printk(dev, NULL, "DMA-API: mapping sg segment longer than device claims to support [len=%u] [max=%u]\n",
-			   sg->length, max_seg);
-	/*
-	 * In some cases this could potentially be the DMA API
-	 * implementation's fault, but it would usually imply that
-	 * the scatterlist was built inappropriately to begin with.
-	 */
-	start = sg_dma_address(sg);
-	end = start + sg_dma_len(sg) - 1;
-	if ((start ^ end) & ~boundary)
-		err_printk(dev, NULL, "DMA-API: mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n",
-			   start, end, boundary);
-#endif
-}
-
-void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
-			size_t size, int direction, dma_addr_t dma_addr,
-			bool map_single)
-{
-	struct dma_debug_entry *entry;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	if (dma_mapping_error(dev, dma_addr))
-		return;
-
-	entry = dma_entry_alloc();
-	if (!entry)
-		return;
-
-	entry->dev       = dev;
-	entry->type      = dma_debug_page;
-	entry->pfn	 = page_to_pfn(page);
-	entry->offset	 = offset,
-	entry->dev_addr  = dma_addr;
-	entry->size      = size;
-	entry->direction = direction;
-	entry->map_err_type = MAP_ERR_NOT_CHECKED;
-
-	if (map_single)
-		entry->type = dma_debug_single;
-
-	check_for_stack(dev, page, offset);
-
-	if (!PageHighMem(page)) {
-		void *addr = page_address(page) + offset;
-
-		check_for_illegal_area(dev, addr, size);
-	}
-
-	add_dma_entry(entry);
-}
-EXPORT_SYMBOL(debug_dma_map_page);
-
-void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
-	struct dma_debug_entry ref;
-	struct dma_debug_entry *entry;
-	struct hash_bucket *bucket;
-	unsigned long flags;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	ref.dev = dev;
-	ref.dev_addr = dma_addr;
-	bucket = get_hash_bucket(&ref, &flags);
-
-	list_for_each_entry(entry, &bucket->list, list) {
-		if (!exact_match(&ref, entry))
-			continue;
-
-		/*
-		 * The same physical address can be mapped multiple
-		 * times. Without a hardware IOMMU this results in the
-		 * same device addresses being put into the dma-debug
-		 * hash multiple times too. This can result in false
-		 * positives being reported. Therefore we implement a
-		 * best-fit algorithm here which updates the first entry
-		 * from the hash which fits the reference value and is
-		 * not currently listed as being checked.
-		 */
-		if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
-			entry->map_err_type = MAP_ERR_CHECKED;
-			break;
-		}
-	}
-
-	put_hash_bucket(bucket, &flags);
-}
-EXPORT_SYMBOL(debug_dma_mapping_error);
-
-void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
-			  size_t size, int direction, bool map_single)
-{
-	struct dma_debug_entry ref = {
-		.type           = dma_debug_page,
-		.dev            = dev,
-		.dev_addr       = addr,
-		.size           = size,
-		.direction      = direction,
-	};
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	if (map_single)
-		ref.type = dma_debug_single;
-
-	check_unmap(&ref);
-}
-EXPORT_SYMBOL(debug_dma_unmap_page);
-
-void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
-		      int nents, int mapped_ents, int direction)
-{
-	struct dma_debug_entry *entry;
-	struct scatterlist *s;
-	int i;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	for_each_sg(sg, s, mapped_ents, i) {
-		entry = dma_entry_alloc();
-		if (!entry)
-			return;
-
-		entry->type           = dma_debug_sg;
-		entry->dev            = dev;
-		entry->pfn	      = page_to_pfn(sg_page(s));
-		entry->offset	      = s->offset,
-		entry->size           = sg_dma_len(s);
-		entry->dev_addr       = sg_dma_address(s);
-		entry->direction      = direction;
-		entry->sg_call_ents   = nents;
-		entry->sg_mapped_ents = mapped_ents;
-
-		check_for_stack(dev, sg_page(s), s->offset);
-
-		if (!PageHighMem(sg_page(s))) {
-			check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
-		}
-
-		check_sg_segment(dev, s);
-
-		add_dma_entry(entry);
-	}
-}
-EXPORT_SYMBOL(debug_dma_map_sg);
-
-static int get_nr_mapped_entries(struct device *dev,
-				 struct dma_debug_entry *ref)
-{
-	struct dma_debug_entry *entry;
-	struct hash_bucket *bucket;
-	unsigned long flags;
-	int mapped_ents;
-
-	bucket       = get_hash_bucket(ref, &flags);
-	entry        = bucket_find_exact(bucket, ref);
-	mapped_ents  = 0;
-
-	if (entry)
-		mapped_ents = entry->sg_mapped_ents;
-	put_hash_bucket(bucket, &flags);
-
-	return mapped_ents;
-}
-
-void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
-			int nelems, int dir)
-{
-	struct scatterlist *s;
-	int mapped_ents = 0, i;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	for_each_sg(sglist, s, nelems, i) {
-
-		struct dma_debug_entry ref = {
-			.type           = dma_debug_sg,
-			.dev            = dev,
-			.pfn		= page_to_pfn(sg_page(s)),
-			.offset		= s->offset,
-			.dev_addr       = sg_dma_address(s),
-			.size           = sg_dma_len(s),
-			.direction      = dir,
-			.sg_call_ents   = nelems,
-		};
-
-		if (mapped_ents && i >= mapped_ents)
-			break;
-
-		if (!i)
-			mapped_ents = get_nr_mapped_entries(dev, &ref);
-
-		check_unmap(&ref);
-	}
-}
-EXPORT_SYMBOL(debug_dma_unmap_sg);
-
-void debug_dma_alloc_coherent(struct device *dev, size_t size,
-			      dma_addr_t dma_addr, void *virt)
-{
-	struct dma_debug_entry *entry;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	if (unlikely(virt == NULL))
-		return;
-
-	/* handle vmalloc and linear addresses */
-	if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
-		return;
-
-	entry = dma_entry_alloc();
-	if (!entry)
-		return;
-
-	entry->type      = dma_debug_coherent;
-	entry->dev       = dev;
-	entry->offset	 = offset_in_page(virt);
-	entry->size      = size;
-	entry->dev_addr  = dma_addr;
-	entry->direction = DMA_BIDIRECTIONAL;
-
-	if (is_vmalloc_addr(virt))
-		entry->pfn = vmalloc_to_pfn(virt);
-	else
-		entry->pfn = page_to_pfn(virt_to_page(virt));
-
-	add_dma_entry(entry);
-}
-EXPORT_SYMBOL(debug_dma_alloc_coherent);
-
-void debug_dma_free_coherent(struct device *dev, size_t size,
-			 void *virt, dma_addr_t addr)
-{
-	struct dma_debug_entry ref = {
-		.type           = dma_debug_coherent,
-		.dev            = dev,
-		.offset		= offset_in_page(virt),
-		.dev_addr       = addr,
-		.size           = size,
-		.direction      = DMA_BIDIRECTIONAL,
-	};
-
-	/* handle vmalloc and linear addresses */
-	if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
-		return;
-
-	if (is_vmalloc_addr(virt))
-		ref.pfn = vmalloc_to_pfn(virt);
-	else
-		ref.pfn = page_to_pfn(virt_to_page(virt));
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	check_unmap(&ref);
-}
-EXPORT_SYMBOL(debug_dma_free_coherent);
-
-void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
-			    int direction, dma_addr_t dma_addr)
-{
-	struct dma_debug_entry *entry;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	entry = dma_entry_alloc();
-	if (!entry)
-		return;
-
-	entry->type		= dma_debug_resource;
-	entry->dev		= dev;
-	entry->pfn		= PHYS_PFN(addr);
-	entry->offset		= offset_in_page(addr);
-	entry->size		= size;
-	entry->dev_addr		= dma_addr;
-	entry->direction	= direction;
-	entry->map_err_type	= MAP_ERR_NOT_CHECKED;
-
-	add_dma_entry(entry);
-}
-EXPORT_SYMBOL(debug_dma_map_resource);
-
-void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
-			      size_t size, int direction)
-{
-	struct dma_debug_entry ref = {
-		.type           = dma_debug_resource,
-		.dev            = dev,
-		.dev_addr       = dma_addr,
-		.size           = size,
-		.direction      = direction,
-	};
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	check_unmap(&ref);
-}
-EXPORT_SYMBOL(debug_dma_unmap_resource);
-
-void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
-				   size_t size, int direction)
-{
-	struct dma_debug_entry ref;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	ref.type         = dma_debug_single;
-	ref.dev          = dev;
-	ref.dev_addr     = dma_handle;
-	ref.size         = size;
-	ref.direction    = direction;
-	ref.sg_call_ents = 0;
-
-	check_sync(dev, &ref, true);
-}
-EXPORT_SYMBOL(debug_dma_sync_single_for_cpu);
-
-void debug_dma_sync_single_for_device(struct device *dev,
-				      dma_addr_t dma_handle, size_t size,
-				      int direction)
-{
-	struct dma_debug_entry ref;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	ref.type         = dma_debug_single;
-	ref.dev          = dev;
-	ref.dev_addr     = dma_handle;
-	ref.size         = size;
-	ref.direction    = direction;
-	ref.sg_call_ents = 0;
-
-	check_sync(dev, &ref, false);
-}
-EXPORT_SYMBOL(debug_dma_sync_single_for_device);
-
-void debug_dma_sync_single_range_for_cpu(struct device *dev,
-					 dma_addr_t dma_handle,
-					 unsigned long offset, size_t size,
-					 int direction)
-{
-	struct dma_debug_entry ref;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	ref.type         = dma_debug_single;
-	ref.dev          = dev;
-	ref.dev_addr     = dma_handle;
-	ref.size         = offset + size;
-	ref.direction    = direction;
-	ref.sg_call_ents = 0;
-
-	check_sync(dev, &ref, true);
-}
-EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu);
-
-void debug_dma_sync_single_range_for_device(struct device *dev,
-					    dma_addr_t dma_handle,
-					    unsigned long offset,
-					    size_t size, int direction)
-{
-	struct dma_debug_entry ref;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	ref.type         = dma_debug_single;
-	ref.dev          = dev;
-	ref.dev_addr     = dma_handle;
-	ref.size         = offset + size;
-	ref.direction    = direction;
-	ref.sg_call_ents = 0;
-
-	check_sync(dev, &ref, false);
-}
-EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
-
-void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
-			       int nelems, int direction)
-{
-	struct scatterlist *s;
-	int mapped_ents = 0, i;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	for_each_sg(sg, s, nelems, i) {
-
-		struct dma_debug_entry ref = {
-			.type           = dma_debug_sg,
-			.dev            = dev,
-			.pfn		= page_to_pfn(sg_page(s)),
-			.offset		= s->offset,
-			.dev_addr       = sg_dma_address(s),
-			.size           = sg_dma_len(s),
-			.direction      = direction,
-			.sg_call_ents   = nelems,
-		};
-
-		if (!i)
-			mapped_ents = get_nr_mapped_entries(dev, &ref);
-
-		if (i >= mapped_ents)
-			break;
-
-		check_sync(dev, &ref, true);
-	}
-}
-EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
-
-void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
-				  int nelems, int direction)
-{
-	struct scatterlist *s;
-	int mapped_ents = 0, i;
-
-	if (unlikely(dma_debug_disabled()))
-		return;
-
-	for_each_sg(sg, s, nelems, i) {
-
-		struct dma_debug_entry ref = {
-			.type           = dma_debug_sg,
-			.dev            = dev,
-			.pfn		= page_to_pfn(sg_page(s)),
-			.offset		= s->offset,
-			.dev_addr       = sg_dma_address(s),
-			.size           = sg_dma_len(s),
-			.direction      = direction,
-			.sg_call_ents   = nelems,
-		};
-		if (!i)
-			mapped_ents = get_nr_mapped_entries(dev, &ref);
-
-		if (i >= mapped_ents)
-			break;
-
-		check_sync(dev, &ref, false);
-	}
-}
-EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
-
-static int __init dma_debug_driver_setup(char *str)
-{
-	int i;
-
-	for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
-		current_driver_name[i] = *str;
-		if (*str == 0)
-			break;
-	}
-
-	if (current_driver_name[0])
-		pr_info("DMA-API: enable driver filter for driver [%s]\n",
-			current_driver_name);
-
-
-	return 1;
-}
-__setup("dma_debug_driver=", dma_debug_driver_setup);