[net-next-2.6.git] / drivers / char / ramoops.c

/*
 * 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>
#include <linux/platform_device.h>
#include <linux/ramoops.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(&timestamp);
	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_probe(struct platform_device *pdev)
{
	struct ramoops_platform_data *pdata = pdev->dev.platform_data;
	struct ramoops_context *cxt = &oops_cxt;
	int err = -EINVAL;

	if (pdata) {
		mem_size = pdata->mem_size;
		mem_address = pdata->mem_address;
	}

	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 int __exit ramoops_remove(struct platform_device *pdev)
{
	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);
	return 0;
}

static struct platform_driver ramoops_driver = {
	.remove		= __exit_p(ramoops_remove),
	.driver		= {
		.name	= "ramoops",
		.owner	= THIS_MODULE,
	},
};

static int __init ramoops_init(void)
{
	return platform_driver_probe(&ramoops_driver, ramoops_probe);
}

static void __exit ramoops_exit(void)
{
	platform_driver_unregister(&ramoops_driver);
}

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");
Commit	Line	Data
56d611a0 MS	1	/*
	2	* RAM Oops/Panic logger
	3	*
	4	* Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* version 2 as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful, but
	11	* WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	18	* 02110-1301 USA
	19	*
	20	*/
	21
	22	#include <linux/kernel.h>
	23	#include <linux/module.h>
	24	#include <linux/kmsg_dump.h>
	25	#include <linux/time.h>
	26	#include <linux/io.h>
	27	#include <linux/ioport.h>
c3b92ce9 KP	28	#include <linux/platform_device.h>
c3b92ce9 KP	29	#include <linux/ramoops.h>
56d611a0 MS	30
	31	#define RAMOOPS_KERNMSG_HDR "===="
	32	#define RAMOOPS_HEADER_SIZE (5 + sizeof(struct timeval))
	33
	34	#define RECORD_SIZE 4096
	35
	36	static ulong mem_address;
	37	module_param(mem_address, ulong, 0400);
	38	MODULE_PARM_DESC(mem_address,
	39	"start of reserved RAM used to store oops/panic logs");
	40
	41	static ulong mem_size;
	42	module_param(mem_size, ulong, 0400);
	43	MODULE_PARM_DESC(mem_size,
	44	"size of reserved RAM used to store oops/panic logs");
	45
	46	static int dump_oops = 1;
	47	module_param(dump_oops, int, 0600);
	48	MODULE_PARM_DESC(dump_oops,
	49	"set to 1 to dump oopses, 0 to only dump panics (default 1)");
	50
	51	static struct ramoops_context {
	52	struct kmsg_dumper dump;
	53	void *virt_addr;
	54	phys_addr_t phys_addr;
	55	unsigned long size;
	56	int count;
	57	int max_count;
	58	} oops_cxt;
	59
	60	static void ramoops_do_dump(struct kmsg_dumper *dumper,
	61	enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
	62	const char *s2, unsigned long l2)
	63	{
	64	struct ramoops_context *cxt = container_of(dumper,
	65	struct ramoops_context, dump);
	66	unsigned long s1_start, s2_start;
	67	unsigned long l1_cpy, l2_cpy;
	68	int res;
	69	char *buf;
	70	struct timeval timestamp;
	71
	72	/* Only dump oopses if dump_oops is set */
	73	if (reason == KMSG_DUMP_OOPS && !dump_oops)
	74	return;
	75
	76	buf = (char )(cxt->virt_addr + (cxt->count RECORD_SIZE));
	77	memset(buf, '\0', RECORD_SIZE);
	78	res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
	79	buf += res;
	80	do_gettimeofday(&timestamp);
	81	res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
	82	buf += res;
	83
	84	l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE));
	85	l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE) - l2_cpy);
	86
	87	s2_start = l2 - l2_cpy;
	88	s1_start = l1 - l1_cpy;
	89
	90	memcpy(buf, s1 + s1_start, l1_cpy);
	91	memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
	92
	93	cxt->count = (cxt->count + 1) % cxt->max_count;
94	}
95
c3b92ce9	96	static int __init ramoops_probe(struct platform_device *pdev)
56d611a0	97	{
c3b92ce9	98	struct ramoops_platform_data *pdata = pdev->dev.platform_data;
56d611a0 MS	99	struct ramoops_context *cxt = &oops_cxt;
	100	int err = -EINVAL;
	101
c3b92ce9 KP	102	if (pdata) {
	103	mem_size = pdata->mem_size;
	104	mem_address = pdata->mem_address;
	105	}
	106
56d611a0 MS	107	if (!mem_size) {
	108	printk(KERN_ERR "ramoops: invalid size specification");
	109	goto fail3;
	110	}
	111
	112	rounddown_pow_of_two(mem_size);
	113
	114	if (mem_size < RECORD_SIZE) {
	115	printk(KERN_ERR "ramoops: size too small");
	116	goto fail3;
	117	}
	118
	119	cxt->max_count = mem_size / RECORD_SIZE;
	120	cxt->count = 0;
	121	cxt->size = mem_size;
	122	cxt->phys_addr = mem_address;
	123
	124	if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
	125	printk(KERN_ERR "ramoops: request mem region failed");
	126	err = -EINVAL;
	127	goto fail3;
	128	}
	129
	130	cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
	131	if (!cxt->virt_addr) {
	132	printk(KERN_ERR "ramoops: ioremap failed");
	133	goto fail2;
	134	}
	135
	136	cxt->dump.dump = ramoops_do_dump;
	137	err = kmsg_dump_register(&cxt->dump);
	138	if (err) {
	139	printk(KERN_ERR "ramoops: registering kmsg dumper failed");
	140	goto fail1;
	141	}
	142
	143	return 0;
	144
	145	fail1:
	146	iounmap(cxt->virt_addr);
	147	fail2:
	148	release_mem_region(cxt->phys_addr, cxt->size);
	149	fail3:
	150	return err;
	151	}
	152
c3b92ce9	153	static int __exit ramoops_remove(struct platform_device *pdev)
56d611a0 MS	154	{
	155	struct ramoops_context *cxt = &oops_cxt;
	156
	157	if (kmsg_dump_unregister(&cxt->dump) < 0)
	158	printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
	159
	160	iounmap(cxt->virt_addr);
	161	release_mem_region(cxt->phys_addr, cxt->size);
c3b92ce9	162	return 0;
56d611a0 MS	163	}
56d611a0 MS	164
c3b92ce9 KP	165	static struct platform_driver ramoops_driver = {
	166	.remove = __exit_p(ramoops_remove),
	167	.driver = {
	168	.name = "ramoops",
	169	.owner = THIS_MODULE,
	170	},
	171	};
	172
	173	static int __init ramoops_init(void)
	174	{
	175	return platform_driver_probe(&ramoops_driver, ramoops_probe);
	176	}
	177
	178	static void __exit ramoops_exit(void)
	179	{
	180	platform_driver_unregister(&ramoops_driver);
	181	}
56d611a0 MS	182
	183	module_init(ramoops_init);
	184	module_exit(ramoops_exit);
	185
	186	MODULE_LICENSE("GPL");
	187	MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
	188	MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");