[deliverable/linux.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
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/slab.h>
#include <linux/ramoops.h>

#define RAMOOPS_KERNMSG_HDR "===="
#define MIN_MEM_SIZE 4096UL

static ulong record_size = MIN_MEM_SIZE;
module_param(record_size, ulong, 0400);
MODULE_PARM_DESC(record_size,
		"size of each dump done on oops/panic");

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;
	unsigned long record_size;
	int dump_oops;
	int count;
	int max_count;
} oops_cxt;

static struct platform_device *dummy;
static struct ramoops_platform_data *dummy_data;

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, hdr_size;
	char *buf, *buf_orig;
	struct timeval timestamp;

	if (reason != KMSG_DUMP_OOPS &&
	    reason != KMSG_DUMP_PANIC &&
	    reason != KMSG_DUMP_KEXEC)
		return;

	/* Only dump oopses if dump_oops is set */
	if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
		return;

	buf = cxt->virt_addr + (cxt->count * cxt->record_size);
	buf_orig = buf;

	memset(buf, '\0', cxt->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;

	hdr_size = buf - buf_orig;
	l2_cpy = min(l2, cxt->record_size - hdr_size);
	l1_cpy = min(l1, cxt->record_size - hdr_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->record_size) {
		pr_err("The memory size and the record size must be "
			"non-zero\n");
		goto fail3;
	}

	rounddown_pow_of_two(pdata->mem_size);
	rounddown_pow_of_two(pdata->record_size);

	/* Check for the minimum memory size */
	if (pdata->mem_size < MIN_MEM_SIZE &&
			pdata->record_size < MIN_MEM_SIZE) {
		pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE);
		goto fail3;
	}

	if (pdata->mem_size < pdata->record_size) {
		pr_err("The memory size must be larger than the "
			"records size\n");
		goto fail3;
	}

	cxt->max_count = pdata->mem_size / pdata->record_size;
	cxt->count = 0;
	cxt->size = pdata->mem_size;
	cxt->phys_addr = pdata->mem_address;
	cxt->record_size = pdata->record_size;
	cxt->dump_oops = pdata->dump_oops;

	if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
		pr_err("request mem region failed\n");
		err = -EINVAL;
		goto fail3;
	}

	cxt->virt_addr = ioremap(cxt->phys_addr,  cxt->size);
	if (!cxt->virt_addr) {
		pr_err("ioremap failed\n");
		goto fail2;
	}

	cxt->dump.dump = ramoops_do_dump;
	err = kmsg_dump_register(&cxt->dump);
	if (err) {
		pr_err("registering kmsg dumper failed\n");
		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)
		pr_warn("could not unregister kmsg_dumper\n");

	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)
{
	int ret;
	ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
	if (ret == -ENODEV) {
		/*
		 * If we didn't find a platform device, we use module parameters
		 * building platform data on the fly.
		 */
		pr_info("platform device not found, using module parameters\n");
		dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
				     GFP_KERNEL);
		if (!dummy_data)
			return -ENOMEM;
		dummy_data->mem_size = mem_size;
		dummy_data->mem_address = mem_address;
		dummy_data->record_size = record_size;
		dummy_data->dump_oops = dump_oops;
		dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
			NULL, 0, dummy_data,
			sizeof(struct ramoops_platform_data));

		if (IS_ERR(dummy))
			ret = PTR_ERR(dummy);
		else
			ret = 0;
	}

	return ret;
}

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

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
0169256e MS	22	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0169256e MS	23
56d611a0 MS	24	#include <linux/kernel.h>
	25	#include <linux/module.h>
	26	#include <linux/kmsg_dump.h>
	27	#include <linux/time.h>
	28	#include <linux/io.h>
	29	#include <linux/ioport.h>
c3b92ce9	30	#include <linux/platform_device.h>
13aefd72	31	#include <linux/slab.h>
c3b92ce9	32	#include <linux/ramoops.h>
56d611a0 MS	33
56d611a0 MS	34	#define RAMOOPS_KERNMSG_HDR "===="
3e5c4fad	35	#define MIN_MEM_SIZE 4096UL
56d611a0	36
3e5c4fad SI	37	static ulong record_size = MIN_MEM_SIZE;
	38	module_param(record_size, ulong, 0400);
	39	MODULE_PARM_DESC(record_size,
	40	"size of each dump done on oops/panic");
56d611a0 MS	41
	42	static ulong mem_address;
	43	module_param(mem_address, ulong, 0400);
	44	MODULE_PARM_DESC(mem_address,
	45	"start of reserved RAM used to store oops/panic logs");
	46
	47	static ulong mem_size;
	48	module_param(mem_size, ulong, 0400);
	49	MODULE_PARM_DESC(mem_size,
	50	"size of reserved RAM used to store oops/panic logs");
	51
	52	static int dump_oops = 1;
	53	module_param(dump_oops, int, 0600);
	54	MODULE_PARM_DESC(dump_oops,
	55	"set to 1 to dump oopses, 0 to only dump panics (default 1)");
	56
	57	static struct ramoops_context {
	58	struct kmsg_dumper dump;
	59	void *virt_addr;
	60	phys_addr_t phys_addr;
	61	unsigned long size;
3e5c4fad	62	unsigned long record_size;
6b4d2a27	63	int dump_oops;
56d611a0 MS	64	int count;
	65	int max_count;
	66	} oops_cxt;
	67
13aefd72 MS	68	static struct platform_device *dummy;
	69	static struct ramoops_platform_data *dummy_data;
	70
56d611a0 MS	71	static void ramoops_do_dump(struct kmsg_dumper *dumper,
	72	enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
	73	const char *s2, unsigned long l2)
	74	{
	75	struct ramoops_context *cxt = container_of(dumper,
	76	struct ramoops_context, dump);
	77	unsigned long s1_start, s2_start;
	78	unsigned long l1_cpy, l2_cpy;
1873bb81 AD	79	int res, hdr_size;
1873bb81 AD	80	char buf, buf_orig;
56d611a0 MS	81	struct timeval timestamp;
56d611a0 MS	82
fc2d557c SA	83	if (reason != KMSG_DUMP_OOPS &&
	84	reason != KMSG_DUMP_PANIC &&
	85	reason != KMSG_DUMP_KEXEC)
	86	return;
	87
56d611a0	88	/* Only dump oopses if dump_oops is set */
6b4d2a27	89	if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
56d611a0 MS	90	return;
56d611a0 MS	91
3e5c4fad	92	buf = cxt->virt_addr + (cxt->count * cxt->record_size);
1873bb81 AD	93	buf_orig = buf;
1873bb81 AD	94
3e5c4fad	95	memset(buf, '\0', cxt->record_size);
56d611a0 MS	96	res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
	97	buf += res;
	98	do_gettimeofday(&timestamp);
	99	res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
	100	buf += res;
	101
1873bb81	102	hdr_size = buf - buf_orig;
3e5c4fad SI	103	l2_cpy = min(l2, cxt->record_size - hdr_size);
3e5c4fad SI	104	l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy);
56d611a0 MS	105
	106	s2_start = l2 - l2_cpy;
	107	s1_start = l1 - l1_cpy;
	108
	109	memcpy(buf, s1 + s1_start, l1_cpy);
	110	memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
	111
	112	cxt->count = (cxt->count + 1) % cxt->max_count;
	113	}
	114
c3b92ce9	115	static int __init ramoops_probe(struct platform_device *pdev)
56d611a0	116	{
c3b92ce9	117	struct ramoops_platform_data *pdata = pdev->dev.platform_data;
56d611a0 MS	118	struct ramoops_context *cxt = &oops_cxt;
	119	int err = -EINVAL;
	120
3e5c4fad SI	121	if (!pdata->mem_size \|\| !pdata->record_size) {
	122	pr_err("The memory size and the record size must be "
	123	"non-zero\n");
56d611a0 MS	124	goto fail3;
	125	}
	126
13aefd72	127	rounddown_pow_of_two(pdata->mem_size);
3e5c4fad	128	rounddown_pow_of_two(pdata->record_size);
56d611a0	129
3e5c4fad SI	130	/* Check for the minimum memory size */
	131	if (pdata->mem_size < MIN_MEM_SIZE &&
	132	pdata->record_size < MIN_MEM_SIZE) {
	133	pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE);
56d611a0 MS	134	goto fail3;
	135	}
	136
3e5c4fad SI	137	if (pdata->mem_size < pdata->record_size) {
	138	pr_err("The memory size must be larger than the "
	139	"records size\n");
	140	goto fail3;
	141	}
	142
	143	cxt->max_count = pdata->mem_size / pdata->record_size;
56d611a0	144	cxt->count = 0;
13aefd72 MS	145	cxt->size = pdata->mem_size;
13aefd72 MS	146	cxt->phys_addr = pdata->mem_address;
3e5c4fad	147	cxt->record_size = pdata->record_size;
6b4d2a27	148	cxt->dump_oops = pdata->dump_oops;
56d611a0 MS	149
56d611a0 MS	150	if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
0169256e	151	pr_err("request mem region failed\n");
56d611a0 MS	152	err = -EINVAL;
	153	goto fail3;
	154	}
	155
	156	cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
	157	if (!cxt->virt_addr) {
0169256e	158	pr_err("ioremap failed\n");
56d611a0 MS	159	goto fail2;
	160	}
	161
	162	cxt->dump.dump = ramoops_do_dump;
	163	err = kmsg_dump_register(&cxt->dump);
	164	if (err) {
0169256e	165	pr_err("registering kmsg dumper failed\n");
56d611a0 MS	166	goto fail1;
	167	}
	168
	169	return 0;
	170
	171	fail1:
	172	iounmap(cxt->virt_addr);
	173	fail2:
	174	release_mem_region(cxt->phys_addr, cxt->size);
	175	fail3:
	176	return err;
	177	}
	178
c3b92ce9	179	static int __exit ramoops_remove(struct platform_device *pdev)
56d611a0 MS	180	{
	181	struct ramoops_context *cxt = &oops_cxt;
	182
	183	if (kmsg_dump_unregister(&cxt->dump) < 0)
0169256e	184	pr_warn("could not unregister kmsg_dumper\n");
56d611a0 MS	185
	186	iounmap(cxt->virt_addr);
	187	release_mem_region(cxt->phys_addr, cxt->size);
c3b92ce9	188	return 0;
56d611a0 MS	189	}
56d611a0 MS	190
c3b92ce9 KP	191	static struct platform_driver ramoops_driver = {
	192	.remove = __exit_p(ramoops_remove),
	193	.driver = {
	194	.name = "ramoops",
	195	.owner = THIS_MODULE,
	196	},
	197	};
	198
	199	static int __init ramoops_init(void)
	200	{
13aefd72 MS	201	int ret;
	202	ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
	203	if (ret == -ENODEV) {
	204	/*
	205	* If we didn't find a platform device, we use module parameters
	206	* building platform data on the fly.
	207	*/
0169256e	208	pr_info("platform device not found, using module parameters\n");
13aefd72 MS	209	dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
	210	GFP_KERNEL);
	211	if (!dummy_data)
	212	return -ENOMEM;
	213	dummy_data->mem_size = mem_size;
	214	dummy_data->mem_address = mem_address;
3e5c4fad	215	dummy_data->record_size = record_size;
6b4d2a27	216	dummy_data->dump_oops = dump_oops;
13aefd72 MS	217	dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
	218	NULL, 0, dummy_data,
	219	sizeof(struct ramoops_platform_data));
	220
	221	if (IS_ERR(dummy))
	222	ret = PTR_ERR(dummy);
	223	else
	224	ret = 0;
	225	}
	226
	227	return ret;
c3b92ce9 KP	228	}
	229
	230	static void __exit ramoops_exit(void)
	231	{
	232	platform_driver_unregister(&ramoops_driver);
13aefd72	233	kfree(dummy_data);
c3b92ce9	234	}
56d611a0 MS	235
	236	module_init(ramoops_init);
	237	module_exit(ramoops_exit);
	238
	239	MODULE_LICENSE("GPL");
	240	MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
	241	MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");