linux/lib/dma-debug.c
Ingo Molnar f39d1b9792 dma-debug: Fix the overlap() function to be correct and readable
Linus noticed how unclean and buggy the overlap() function is:

 - It uses convoluted (and bug-causing) positive checks for
   range overlap - instead of using a more natural negative
   check.

 - Even the positive checks are buggy: a positive intersection
   check has four natural cases while we checked only for three,
   missing the (addr < start && addr2 == end) case for example.

 - The variables are mis-named, making it non-obvious how the
   check was done.

 - It needlessly uses u64 instead of unsigned long. Since these
   are kernel memory pointers and we explicitly exclude highmem
   ranges anyway we cannot ever overflow 32 bits, even if we
   could. (and on 64-bit it doesnt matter anyway)

All in one, this function needs a total revamp. I used Linus's
suggestions minus the paranoid checks (we cannot overflow really
because if we get totally bad DMA ranges passed far more things
break in the systems than just DMA debugging). I also fixed a
few other small details i noticed.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10 22:18:45 +02:00

1294 lines
31 KiB
C

/*
* 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/uaccess.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)
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;
static u32 nr_total_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 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 *type2name[4] = { "single", "page",
"scather-gather", "coherent" };
static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
"DMA_FROM_DEVICE", "DMA_NONE" };
/* little merge helper - remove it after the merge window */
#ifndef BUS_NOTIFY_UNBOUND_DRIVER
#define BUS_NOTIFY_UNBOUND_DRIVER 0x0005
#endif
/*
* 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->driver == current_driver)
return true;
if (current_driver || !current_driver_name[0])
return false;
/* driver filter on but not yet initialized */
drv = get_driver(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);
put_driver(drv);
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_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, *ret = NULL;
int matches = 0, match_lvl, last_lvl = 0;
list_for_each_entry(entry, &bucket->list, list) {
if ((entry->dev_addr != ref->dev_addr) ||
(entry->dev != ref->dev))
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. Therfore 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
*/
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;
}
/*
* 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);
}
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 = NULL;
unsigned long flags;
spin_lock_irqsave(&free_entries_lock, flags);
if (list_empty(&free_entries)) {
pr_err("DMA-API: debugging out of memory - disabling\n");
global_disable = true;
goto out;
}
entry = __dma_entry_alloc();
#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
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);
}
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;
}
EXPORT_SYMBOL(dma_debug_resize_entries);
/*
* 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; ++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;
}
const struct file_operations filter_fops = {
.read = filter_read,
.write = filter_write,
};
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,
(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;
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 *entry;
unsigned long flags;
int count = 0, i;
local_irq_save(flags);
for (i = 0; i < HASH_SIZE; ++i) {
spin_lock(&dma_entry_hash[i].lock);
list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
if (entry->dev == dev)
count += 1;
}
spin_unlock(&dma_entry_hash[i].lock);
}
local_irq_restore(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_UNBOUND_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) {
pr_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);
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;
}
if (req_entries)
num_entries = req_entries;
if (prealloc_memory(num_entries) != 0) {
pr_err("DMA-API: debugging out of memory error - disabled\n");
global_disable = true;
return;
}
nr_total_entries = num_free_entries;
pr_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) {
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)
{
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)) {
err_printk(ref->dev, NULL, "DMA-API: device driver tries "
"to free an invalid DMA memory address\n");
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, 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, _text, _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 = 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",
(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 (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 (entry->direction == DMA_BIDIRECTIONAL)
goto out;
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]);
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)
entry->type = dma_debug_single;
if (!PageHighMem(page)) {
void *addr = page_address(page) + offset;
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 = 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;
if (!PageHighMem(sg_page(s))) {
check_for_stack(dev, sg_virt(s));
check_for_illegal_area(dev, sg_virt(s), sg_dma_len(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 = hash_bucket_find(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(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 = 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(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)
{
struct dma_debug_entry ref;
if (unlikely(global_disable))
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(global_disable))
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(global_disable))
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(global_disable))
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(global_disable))
return;
for_each_sg(sg, s, nelems, i) {
struct dma_debug_entry ref = {
.type = dma_debug_sg,
.dev = dev,
.paddr = sg_phys(s),
.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(global_disable))
return;
for_each_sg(sg, s, nelems, i) {
struct dma_debug_entry ref = {
.type = dma_debug_sg,
.dev = dev,
.paddr = sg_phys(s),
.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);