/*
* RAM Oops/Panic logger
*
* Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.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., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kmsg_dump.h>
#include <linux/time.h>
#include <linux/io.h>
#include <linux/ioport.h>
#define RAMOOPS_KERNMSG_HDR "===="
#define RAMOOPS_HEADER_SIZE (5 + sizeof(struct timeval))
#define RECORD_SIZE 4096
static ulong mem_address;
module_param(mem_address, ulong, 0400);
MODULE_PARM_DESC(mem_address,
"start of reserved RAM used to store oops/panic logs");
static ulong mem_size;
module_param(mem_size, ulong, 0400);
MODULE_PARM_DESC(mem_size,
"size of reserved RAM used to store oops/panic logs");
static int dump_oops = 1;
module_param(dump_oops, int, 0600);
MODULE_PARM_DESC(dump_oops,
"set to 1 to dump oopses, 0 to only dump panics (default 1)");
static struct ramoops_context {
struct kmsg_dumper dump;
void *virt_addr;
phys_addr_t phys_addr;
unsigned long size;
int count;
int max_count;
} oops_cxt;
static void ramoops_do_dump(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
const char *s2, unsigned long l2)
{
struct ramoops_context *cxt = container_of(dumper,
struct ramoops_context, dump);
unsigned long s1_start, s2_start;
unsigned long l1_cpy, l2_cpy;
int res;
char *buf;
struct timeval timestamp;
/* Only dump oopses if dump_oops is set */
if (reason == KMSG_DUMP_OOPS && !dump_oops)
return;
buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE));
memset(buf, '\0', RECORD_SIZE);
res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
buf += res;
do_gettimeofday(×tamp);
res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
buf += res;
l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE));
l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE) - l2_cpy);
s2_start = l2 - l2_cpy;
s1_start = l1 - l1_cpy;
memcpy(buf, s1 + s1_start, l1_cpy);
memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
cxt->count = (cxt->count + 1) % cxt->max_count;
}
static int __init ramoops_init(void)
{
struct ramoops_context *cxt = &oops_cxt;
int err = -EINVAL;
if (!mem_size) {
printk(KERN_ERR "ramoops: invalid size specification");
goto fail3;
}
rounddown_pow_of_two(mem_size);
if (mem_size < RECORD_SIZE) {
printk(KERN_ERR "ramoops: size too small");
goto fail3;
}
cxt->max_count = mem_size / RECORD_SIZE;
cxt->count = 0;
cxt->size = mem_size;
cxt->phys_addr = mem_address;
if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
printk(KERN_ERR "ramoops: request mem region failed");
err = -EINVAL;
goto fail3;
}
cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
if (!cxt->virt_addr) {
printk(KERN_ERR "ramoops: ioremap failed");
goto fail2;
}
cxt->dump.dump = ramoops_do_dump;
err = kmsg_dump_register(&cxt->dump);
if (err) {
printk(KERN_ERR "ramoops: registering kmsg dumper failed");
goto fail1;
}
return 0;
fail1:
iounmap(cxt->virt_addr);
fail2:
release_mem_region(cxt->phys_addr, cxt->size);
fail3:
return err;
}
static void __exit ramoops_exit(void)
{
struct ramoops_context *cxt = &oops_cxt;
if (kmsg_dump_unregister(&cxt->dump) < 0)
printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
iounmap(cxt->virt_addr);
release_mem_region(cxt->phys_addr, cxt->size);
}
module_init(ramoops_init);
module_exit(ramoops_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
