3 files changed, 962 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1bcf9cd4baa0..d9cbada7e2f8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -902,6 +902,17 @@ config DYNAMIC_PRINTK_DEBUG
           debugging for all modules. This mode can be turned off via the above
           disable command.
 
+config DMA_API_DEBUG
+        bool "Enable debugging of DMA-API usage"
+        depends on HAVE_DMA_API_DEBUG
+        help
+          Enable this option to debug the use of the DMA API by device drivers.
+          With this option you will be able to detect common bugs in device
+          drivers like double-freeing of DMA mappings or freeing mappings that
+          were never allocated.
+          This option causes a performance degredation.  Use only if you want
+          to debug device drivers. If unsure, say N.
+
 source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"
diff --git a/lib/Makefile b/lib/Makefile
index 32b0e64ded27..50b48cf63e4a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -84,6 +84,8 @@ obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
 
 obj-$(CONFIG_DYNAMIC_PRINTK_DEBUG) += dynamic_printk.o
 
+obj-$(CONFIG_DMA_API_DEBUG) += dma-debug.o
+
 hostprogs-y     := gen_crc32table
 clean-files     := crc32table.h
 
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
new file mode 100644
index 000000000000..9a350b414a50
--- /dev/null
+++ b/lib/dma-debug.c
@@ -0,0 +1,949 @@
+/*
+ * 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/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/stacktrace.h>
+#include <linux/dma-debug.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/sched.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)
+
+enum {
+        dma_debug_single,
+        dma_debug_page,
+        dma_debug_sg,
+        dma_debug_coherent,
+};
+
+#define DMA_DEBUG_STACKTRACE_ENTRIES 5
+
+struct dma_debug_entry {
+        struct list_head list;
+        struct device    *dev;
+        int              type;
+        phys_addr_t      paddr;
+        u64              dev_addr;
+        u64              size;
+        int              direction;
+        int              sg_call_ents;
+        int              sg_mapped_ents;
+#ifdef CONFIG_STACKTRACE
+        struct           stack_trace stacktrace;
+        unsigned long    st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
+#endif
+};
+
+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;
+
+/* 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;
+
+/* number of preallocated entries requested by kernel cmdline */
+static u32 req_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 const char *type2name[4] = { "single", "page",
+                                    "scather-gather", "coherent" };
+
+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) {
+                printk(KERN_WARNING "Mapped at:\n");
+                print_stack_trace(&entry->stacktrace, 0);
+        }
+#endif
+}
+
+#define err_printk(dev, entry, format, arg...) do {             \
+                error_count += 1;                               \
+                if (show_all_errors || show_num_errors > 0) {   \
+                        WARN(1, "%s %s: " format,               \
+                             dev_driver_string(dev),            \
+                             dev_name(dev) , ## 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)
+{
+        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)
+{
+        unsigned long __flags = *flags;
+
+        spin_unlock_irqrestore(&bucket->lock, __flags);
+}
+
+/*
+ * 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)
+{
+        struct dma_debug_entry *entry;
+
+        list_for_each_entry(entry, &bucket->list, list) {
+                if ((entry->dev_addr == ref->dev_addr) &&
+                    (entry->dev == ref->dev))
+                        return entry;
+        }
+
+        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);
+}
+
+/*
+ * 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 D=%Lx L=%Lx %s\n",
+                                         type2name[entry->type], idx,
+                                         (unsigned long long)entry->paddr,
+                                         entry->dev_addr, entry->size,
+                                         dir2name[entry->direction]);
+                        }
+                }
+
+                spin_unlock_irqrestore(&bucket->lock, flags);
+        }
+}
+EXPORT_SYMBOL(debug_dma_dump_mappings);
+
+/*
+ * 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;
+
+        bucket = get_hash_bucket(entry, &flags);
+        hash_bucket_add(bucket, entry);
+        put_hash_bucket(bucket, &flags);
+}
+
+/* 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 = NULL;
+        unsigned long flags;
+
+        spin_lock_irqsave(&free_entries_lock, flags);
+
+        if (list_empty(&free_entries)) {
+                printk(KERN_ERR "DMA-API: debugging out of memory "
+                                "- disabling\n");
+                global_disable = true;
+                goto out;
+        }
+
+        entry = list_entry(free_entries.next, struct dma_debug_entry, list);
+        list_del(&entry->list);
+        memset(entry, 0, sizeof(*entry));
+
+#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
+        num_free_entries -= 1;
+        if (num_free_entries < min_free_entries)
+                min_free_entries = num_free_entries;
+
+out:
+        spin_unlock_irqrestore(&free_entries_lock, flags);
+
+        return entry;
+}
+
+static void dma_entry_free(struct dma_debug_entry *entry)
+{
+        unsigned long flags;
+
+        /*
+         * 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);
+}
+
+/*
+ * 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;
+
+        printk(KERN_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 int dma_debug_fs_init(void)
+{
+        dma_debug_dent = debugfs_create_dir("dma-api", NULL);
+        if (!dma_debug_dent) {
+                printk(KERN_ERR "DMA-API: can not create debugfs directory\n");
+                return -ENOMEM;
+        }
+
+        global_disable_dent = debugfs_create_bool("disabled", 0444,
+                        dma_debug_dent,
+                        (u32 *)&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;
+
+        return 0;
+
+out_err:
+        debugfs_remove_recursive(dma_debug_dent);
+
+        return -ENOMEM;
+}
+
+static int device_dma_allocations(struct device *dev)
+{
+        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;
+                }
+                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;
+        int count;
+
+
+        switch (action) {
+        case BUS_NOTIFY_UNBIND_DRIVER:
+                count = device_dma_allocations(dev);
+                if (count == 0)
+                        break;
+                err_printk(dev, NULL, "DMA-API: device driver has pending "
+                                "DMA allocations while released from device "
+                                "[count=%d]\n", count);
+                break;
+        default:
+                break;
+        }
+
+        return 0;
+}
+
+void dma_debug_add_bus(struct bus_type *bus)
+{
+        struct notifier_block *nb;
+
+        nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
+        if (nb == NULL) {
+                printk(KERN_ERR "dma_debug_add_bus: out of memory\n");
+                return;
+        }
+
+        nb->notifier_call = dma_debug_device_change;
+
+        bus_register_notifier(bus, nb);
+}
+
+/*
+ * Let the architectures decide how many entries should be preallocated.
+ */
+void dma_debug_init(u32 num_entries)
+{
+        int i;
+
+        if (global_disable)
+                return;
+
+        for (i = 0; i < HASH_SIZE; ++i) {
+                INIT_LIST_HEAD(&dma_entry_hash[i].list);
+                dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
+        }
+
+        if (dma_debug_fs_init() != 0) {
+                printk(KERN_ERR "DMA-API: error creating debugfs entries "
+                                "- disabling\n");
+                global_disable = true;
+
+                return;
+        }
+
+        if (req_entries)
+                num_entries = req_entries;
+
+        if (prealloc_memory(num_entries) != 0) {
+                printk(KERN_ERR "DMA-API: debugging out of memory error "
+                                "- disabled\n");
+                global_disable = true;
+
+                return;
+        }
+
+        printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
+}
+
+static __init int dma_debug_cmdline(char *str)
+{
+        if (!str)
+                return -EINVAL;
+
+        if (strncmp(str, "off", 3) == 0) {
+                printk(KERN_INFO "DMA-API: debugging disabled on kernel "
+                                 "command line\n");
+                global_disable = true;
+        }
+
+        return 0;
+}
+
+static __init int dma_debug_entries_cmdline(char *str)
+{
+        int res;
+
+        if (!str)
+                return -EINVAL;
+
+        res = get_option(&str, &req_entries);
+
+        if (!res)
+                req_entries = 0;
+
+        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;
+
+        if (dma_mapping_error(ref->dev, ref->dev_addr))
+                return;
+
+        bucket = get_hash_bucket(ref, &flags);
+        entry = hash_bucket_find(bucket, ref);
+
+        if (!entry) {
+                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);
+                goto out;
+        }
+
+        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) &&
+                   (ref->paddr != entry->paddr)) {
+                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=%p] [cpu free address=%p]",
+                           ref->dev_addr, ref->size,
+                           (void *)entry->paddr, (void *)ref->paddr);
+        }
+
+        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]);
+        }
+
+        hash_bucket_del(entry);
+        dma_entry_free(entry);
+
+out:
+        put_hash_bucket(bucket, &flags);
+}
+
+static void check_for_stack(struct device *dev, void *addr)
+{
+        if (object_is_on_stack(addr))
+                err_printk(dev, NULL, "DMA-API: device driver maps memory from"
+                                "stack [addr=%p]\n", addr);
+}
+
+static inline bool overlap(void *addr, u64 size, void *start, void *end)
+{
+        void *addr2 = (char *)addr + size;
+
+        return ((addr >= start && addr < end) ||
+                (addr2 >= start && addr2 < end) ||
+                ((addr < start) && (addr2 >= end)));
+}
+
+static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
+{
+        if (overlap(addr, size, _text, _etext) ||
+            overlap(addr, size, __start_rodata, __end_rodata))
+                err_printk(dev, NULL, "DMA-API: device driver maps "
+                                "memory from kernel text or rodata "
+                                "[addr=%p] [size=%llu]\n", addr, size);
+}
+
+static void check_sync(struct device *dev, dma_addr_t addr,
+                       u64 size, u64 offset, int direction, bool to_cpu)
+{
+        struct dma_debug_entry ref = {
+                .dev            = dev,
+                .dev_addr       = addr,
+                .size           = size,
+                .direction      = direction,
+        };
+        struct dma_debug_entry *entry;
+        struct hash_bucket *bucket;
+        unsigned long flags;
+
+        bucket = get_hash_bucket(&ref, &flags);
+
+        entry = hash_bucket_find(bucket, &ref);
+
+        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",
+                                addr, size);
+                goto out;
+        }
+
+        if ((offset + 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=%llu] "
+                                "[sync size=%llu]\n", entry->dev_addr, entry->size,
+                                offset, size);
+        }
+
+        if (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",
+                                addr, entry->size,
+                                dir2name[entry->direction],
+                                dir2name[direction]);
+        }
+
+        if (entry->direction == DMA_BIDIRECTIONAL)
+                goto out;
+
+        if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
+                      !(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",
+                                addr, entry->size,
+                                dir2name[entry->direction],
+                                dir2name[direction]);
+
+        if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
+                       !(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",
+                                addr, entry->size,
+                                dir2name[entry->direction],
+                                dir2name[direction]);
+
+out:
+        put_hash_bucket(bucket, &flags);
+
+}
+
+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(global_disable))
+                return;
+
+        if (unlikely(dma_mapping_error(dev, dma_addr)))
+                return;
+
+        entry = dma_entry_alloc();
+        if (!entry)
+                return;
+
+        entry->dev       = dev;
+        entry->type      = dma_debug_page;
+        entry->paddr     = page_to_phys(page) + offset;
+        entry->dev_addr  = dma_addr;
+        entry->size      = size;
+        entry->direction = direction;
+
+        if (map_single) {
+                void *addr = ((char *)page_address(page)) + offset;
+
+                entry->type = dma_debug_single;
+                check_for_stack(dev, addr);
+                check_for_illegal_area(dev, addr, size);
+        }
+
+        add_dma_entry(entry);
+}
+EXPORT_SYMBOL(debug_dma_map_page);
+
+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(global_disable))
+                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(global_disable))
+                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->paddr          = sg_phys(s);
+                entry->size           = s->length;
+                entry->dev_addr       = s->dma_address;
+                entry->direction      = direction;
+                entry->sg_call_ents   = nents;
+                entry->sg_mapped_ents = mapped_ents;
+
+                check_for_stack(dev, sg_virt(s));
+                check_for_illegal_area(dev, sg_virt(s), s->length);
+
+                add_dma_entry(entry);
+        }
+}
+EXPORT_SYMBOL(debug_dma_map_sg);
+
+void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
+                        int nelems, int dir)
+{
+        struct dma_debug_entry *entry;
+        struct scatterlist *s;
+        int mapped_ents = 0, i;
+        unsigned long flags;
+
+        if (unlikely(global_disable))
+                return;
+
+        for_each_sg(sglist, s, nelems, i) {
+
+                struct dma_debug_entry ref = {
+                        .type           = dma_debug_sg,
+                        .dev            = dev,
+                        .paddr          = sg_phys(s),
+                        .dev_addr       = s->dma_address,
+                        .size           = s->length,
+                        .direction      = dir,
+                        .sg_call_ents   = 0,
+                };
+
+                if (mapped_ents && i >= mapped_ents)
+                        break;
+
+                if (mapped_ents == 0) {
+                        struct hash_bucket *bucket;
+                        ref.sg_call_ents = nelems;
+                        bucket = get_hash_bucket(&ref, &flags);
+                        entry = hash_bucket_find(bucket, &ref);
+                        if (entry)
+                                mapped_ents = entry->sg_mapped_ents;
+                        put_hash_bucket(bucket, &flags);
+                }
+
+                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(global_disable))
+                return;
+
+        if (unlikely(virt == NULL))
+                return;
+
+        entry = dma_entry_alloc();
+        if (!entry)
+                return;
+
+        entry->type      = dma_debug_coherent;
+        entry->dev       = dev;
+        entry->paddr     = virt_to_phys(virt);
+        entry->size      = size;
+        entry->dev_addr  = dma_addr;
+        entry->direction = DMA_BIDIRECTIONAL;
+
+        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,
+                .paddr          = virt_to_phys(virt),
+                .dev_addr       = addr,
+                .size           = size,
+                .direction      = DMA_BIDIRECTIONAL,
+        };
+
+        if (unlikely(global_disable))
+                return;
+
+        check_unmap(&ref);
+}
+EXPORT_SYMBOL(debug_dma_free_coherent);
+
+void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
+                                   size_t size, int direction)
+{
+        if (unlikely(global_disable))
+                return;
+
+        check_sync(dev, dma_handle, size, 0, direction, 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)
+{
+        if (unlikely(global_disable))
+                return;
+
+        check_sync(dev, dma_handle, size, 0, direction, 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)
+{
+        if (unlikely(global_disable))
+                return;
+
+        check_sync(dev, dma_handle, size, offset, direction, 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)
+{
+        if (unlikely(global_disable))
+                return;
+
+        check_sync(dev, dma_handle, size, offset, direction, 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 i;
+
+        if (unlikely(global_disable))
+                return;
+
+        for_each_sg(sg, s, nelems, i) {
+                check_sync(dev, s->dma_address, s->dma_length, 0,
+                                direction, 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 i;
+
+        if (unlikely(global_disable))
+                return;
+
+        for_each_sg(sg, s, nelems, i) {
+                check_sync(dev, s->dma_address, s->dma_length, 0,
+                                direction, false);
+        }
+}
+EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
+