/*
* 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" };
/*
* 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
}
static bool driver_filter(struct device *dev)
{
/* 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;
/* driver filter on but not yet initialized */
if (!current_driver && current_driver_name[0]) {
struct device_driver *drv = get_driver(dev->driver);
unsigned long flags;
bool ret = false;
if