[mirror_ubuntu-zesty-kernel.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 RECORD_SIZE 4096UL

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 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 * RECORD_SIZE);
	buf_orig = buf;

	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;

	hdr_size = buf - buf_orig;
	l2_cpy = min(l2, RECORD_SIZE - hdr_size);
	l1_cpy = min(l1, 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) {
		pr_err("invalid size specification\n");
		goto fail3;
	}

	rounddown_pow_of_two(pdata->mem_size);

	if (pdata->mem_size < RECORD_SIZE) {
		pr_err("size too small\n");
		goto fail3;
	}

	cxt->max_count = pdata->mem_size / RECORD_SIZE;
	cxt->count = 0;
	cxt->size = pdata->mem_size;
	cxt->phys_addr = pdata->mem_address;
	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->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 "===="
56d611a0	35
264b795f	36	#define RECORD_SIZE 4096UL
56d611a0 MS	37
	38	static ulong mem_address;
	39	module_param(mem_address, ulong, 0400);
	40	MODULE_PARM_DESC(mem_address,
	41	"start of reserved RAM used to store oops/panic logs");
	42
	43	static ulong mem_size;
	44	module_param(mem_size, ulong, 0400);
	45	MODULE_PARM_DESC(mem_size,
	46	"size of reserved RAM used to store oops/panic logs");
	47
	48	static int dump_oops = 1;
	49	module_param(dump_oops, int, 0600);
	50	MODULE_PARM_DESC(dump_oops,
	51	"set to 1 to dump oopses, 0 to only dump panics (default 1)");
	52
	53	static struct ramoops_context {
	54	struct kmsg_dumper dump;
	55	void *virt_addr;
	56	phys_addr_t phys_addr;
	57	unsigned long size;
6b4d2a27	58	int dump_oops;
56d611a0 MS	59	int count;
	60	int max_count;
	61	} oops_cxt;
	62
13aefd72 MS	63	static struct platform_device *dummy;
	64	static struct ramoops_platform_data *dummy_data;
	65
56d611a0 MS	66	static void ramoops_do_dump(struct kmsg_dumper *dumper,
	67	enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
	68	const char *s2, unsigned long l2)
	69	{
	70	struct ramoops_context *cxt = container_of(dumper,
	71	struct ramoops_context, dump);
	72	unsigned long s1_start, s2_start;
	73	unsigned long l1_cpy, l2_cpy;
1873bb81 AD	74	int res, hdr_size;
1873bb81 AD	75	char buf, buf_orig;
56d611a0 MS	76	struct timeval timestamp;
56d611a0 MS	77
fc2d557c SA	78	if (reason != KMSG_DUMP_OOPS &&
	79	reason != KMSG_DUMP_PANIC &&
	80	reason != KMSG_DUMP_KEXEC)
	81	return;
	82
56d611a0	83	/* Only dump oopses if dump_oops is set */
6b4d2a27	84	if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
56d611a0 MS	85	return;
56d611a0 MS	86
264b795f	87	buf = cxt->virt_addr + (cxt->count * RECORD_SIZE);
1873bb81 AD	88	buf_orig = buf;
1873bb81 AD	89
56d611a0 MS	90	memset(buf, '\0', RECORD_SIZE);
	91	res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
	92	buf += res;
	93	do_gettimeofday(&timestamp);
	94	res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
	95	buf += res;
	96
1873bb81	97	hdr_size = buf - buf_orig;
264b795f AM	98	l2_cpy = min(l2, RECORD_SIZE - hdr_size);
264b795f AM	99	l1_cpy = min(l1, RECORD_SIZE - hdr_size - l2_cpy);
56d611a0 MS	100
	101	s2_start = l2 - l2_cpy;
	102	s1_start = l1 - l1_cpy;
	103
	104	memcpy(buf, s1 + s1_start, l1_cpy);
	105	memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
	106
	107	cxt->count = (cxt->count + 1) % cxt->max_count;
	108	}
	109
c3b92ce9	110	static int __init ramoops_probe(struct platform_device *pdev)
56d611a0	111	{
c3b92ce9	112	struct ramoops_platform_data *pdata = pdev->dev.platform_data;
56d611a0 MS	113	struct ramoops_context *cxt = &oops_cxt;
	114	int err = -EINVAL;
	115
13aefd72	116	if (!pdata->mem_size) {
0169256e	117	pr_err("invalid size specification\n");
56d611a0 MS	118	goto fail3;
	119	}
	120
13aefd72	121	rounddown_pow_of_two(pdata->mem_size);
56d611a0	122
13aefd72	123	if (pdata->mem_size < RECORD_SIZE) {
0169256e	124	pr_err("size too small\n");
56d611a0 MS	125	goto fail3;
	126	}
	127
13aefd72	128	cxt->max_count = pdata->mem_size / RECORD_SIZE;
56d611a0	129	cxt->count = 0;
13aefd72 MS	130	cxt->size = pdata->mem_size;
13aefd72 MS	131	cxt->phys_addr = pdata->mem_address;
6b4d2a27	132	cxt->dump_oops = pdata->dump_oops;
56d611a0 MS	133
56d611a0 MS	134	if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
0169256e	135	pr_err("request mem region failed\n");
56d611a0 MS	136	err = -EINVAL;
	137	goto fail3;
	138	}
	139
	140	cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
	141	if (!cxt->virt_addr) {
0169256e	142	pr_err("ioremap failed\n");
56d611a0 MS	143	goto fail2;
	144	}
	145
	146	cxt->dump.dump = ramoops_do_dump;
	147	err = kmsg_dump_register(&cxt->dump);
	148	if (err) {
0169256e	149	pr_err("registering kmsg dumper failed\n");
56d611a0 MS	150	goto fail1;
	151	}
	152
	153	return 0;
	154
	155	fail1:
	156	iounmap(cxt->virt_addr);
	157	fail2:
	158	release_mem_region(cxt->phys_addr, cxt->size);
	159	fail3:
	160	return err;
	161	}
	162
c3b92ce9	163	static int __exit ramoops_remove(struct platform_device *pdev)
56d611a0 MS	164	{
	165	struct ramoops_context *cxt = &oops_cxt;
	166
	167	if (kmsg_dump_unregister(&cxt->dump) < 0)
0169256e	168	pr_warn("could not unregister kmsg_dumper\n");
56d611a0 MS	169
	170	iounmap(cxt->virt_addr);
	171	release_mem_region(cxt->phys_addr, cxt->size);
c3b92ce9	172	return 0;
56d611a0 MS	173	}
56d611a0 MS	174
c3b92ce9 KP	175	static struct platform_driver ramoops_driver = {
	176	.remove = __exit_p(ramoops_remove),
	177	.driver = {
	178	.name = "ramoops",
	179	.owner = THIS_MODULE,
	180	},
	181	};
	182
	183	static int __init ramoops_init(void)
	184	{
13aefd72 MS	185	int ret;
	186	ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
	187	if (ret == -ENODEV) {
	188	/*
	189	* If we didn't find a platform device, we use module parameters
	190	* building platform data on the fly.
	191	*/
0169256e	192	pr_info("platform device not found, using module parameters\n");
13aefd72 MS	193	dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
	194	GFP_KERNEL);
	195	if (!dummy_data)
	196	return -ENOMEM;
	197	dummy_data->mem_size = mem_size;
	198	dummy_data->mem_address = mem_address;
6b4d2a27	199	dummy_data->dump_oops = dump_oops;
13aefd72 MS	200	dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
	201	NULL, 0, dummy_data,
	202	sizeof(struct ramoops_platform_data));
	203
	204	if (IS_ERR(dummy))
	205	ret = PTR_ERR(dummy);
	206	else
	207	ret = 0;
	208	}
	209
	210	return ret;
c3b92ce9 KP	211	}
	212
	213	static void __exit ramoops_exit(void)
	214	{
	215	platform_driver_unregister(&ramoops_driver);
13aefd72	216	kfree(dummy_data);
c3b92ce9	217	}
56d611a0 MS	218
	219	module_init(ramoops_init);
	220	module_exit(ramoops_exit);
	221
	222	MODULE_LICENSE("GPL");
	223	MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
	224	MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");