[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/err.h>
#include <linux/module.h>
#include <linux/kmsg_dump.h>
#include <linux/time.h>
#include <linux/err.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)
		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;
	/*
	 * Update the module parameter variables as well so they are visible
	 * through /sys/module/ramoops/parameters/
	 */
	mem_size = pdata->mem_size;
	mem_address = pdata->mem_address;
	record_size = pdata->record_size;
	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	24	#include <linux/kernel.h>
83c1b317	25	#include <linux/err.h>
56d611a0 MS	26	#include <linux/module.h>
	27	#include <linux/kmsg_dump.h>
	28	#include <linux/time.h>
c05aa8fb	29	#include <linux/err.h>
56d611a0 MS	30	#include <linux/io.h>
56d611a0 MS	31	#include <linux/ioport.h>
c3b92ce9	32	#include <linux/platform_device.h>
13aefd72	33	#include <linux/slab.h>
c3b92ce9	34	#include <linux/ramoops.h>
56d611a0 MS	35
56d611a0 MS	36	#define RAMOOPS_KERNMSG_HDR "===="
3e5c4fad	37	#define MIN_MEM_SIZE 4096UL
56d611a0	38
3e5c4fad SI	39	static ulong record_size = MIN_MEM_SIZE;
	40	module_param(record_size, ulong, 0400);
	41	MODULE_PARM_DESC(record_size,
	42	"size of each dump done on oops/panic");
56d611a0 MS	43
	44	static ulong mem_address;
	45	module_param(mem_address, ulong, 0400);
	46	MODULE_PARM_DESC(mem_address,
	47	"start of reserved RAM used to store oops/panic logs");
	48
	49	static ulong mem_size;
	50	module_param(mem_size, ulong, 0400);
	51	MODULE_PARM_DESC(mem_size,
	52	"size of reserved RAM used to store oops/panic logs");
	53
	54	static int dump_oops = 1;
	55	module_param(dump_oops, int, 0600);
	56	MODULE_PARM_DESC(dump_oops,
	57	"set to 1 to dump oopses, 0 to only dump panics (default 1)");
	58
	59	static struct ramoops_context {
	60	struct kmsg_dumper dump;
	61	void *virt_addr;
	62	phys_addr_t phys_addr;
	63	unsigned long size;
3e5c4fad	64	unsigned long record_size;
6b4d2a27	65	int dump_oops;
56d611a0 MS	66	int count;
	67	int max_count;
	68	} oops_cxt;
	69
13aefd72 MS	70	static struct platform_device *dummy;
	71	static struct ramoops_platform_data *dummy_data;
	72
56d611a0 MS	73	static void ramoops_do_dump(struct kmsg_dumper *dumper,
	74	enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
	75	const char *s2, unsigned long l2)
	76	{
	77	struct ramoops_context *cxt = container_of(dumper,
	78	struct ramoops_context, dump);
	79	unsigned long s1_start, s2_start;
	80	unsigned long l1_cpy, l2_cpy;
1873bb81 AD	81	int res, hdr_size;
1873bb81 AD	82	char buf, buf_orig;
56d611a0 MS	83	struct timeval timestamp;
56d611a0 MS	84
fc2d557c	85	if (reason != KMSG_DUMP_OOPS &&
a3dd3323	86	reason != KMSG_DUMP_PANIC)
fc2d557c SA	87	return;
fc2d557c SA	88
56d611a0	89	/* Only dump oopses if dump_oops is set */
6b4d2a27	90	if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
56d611a0 MS	91	return;
56d611a0 MS	92
3e5c4fad	93	buf = cxt->virt_addr + (cxt->count * cxt->record_size);
1873bb81 AD	94	buf_orig = buf;
1873bb81 AD	95
3e5c4fad	96	memset(buf, '\0', cxt->record_size);
56d611a0 MS	97	res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
	98	buf += res;
	99	do_gettimeofday(&timestamp);
	100	res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
	101	buf += res;
	102
1873bb81	103	hdr_size = buf - buf_orig;
3e5c4fad SI	104	l2_cpy = min(l2, cxt->record_size - hdr_size);
3e5c4fad SI	105	l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy);
56d611a0 MS	106
	107	s2_start = l2 - l2_cpy;
	108	s1_start = l1 - l1_cpy;
	109
	110	memcpy(buf, s1 + s1_start, l1_cpy);
	111	memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
	112
	113	cxt->count = (cxt->count + 1) % cxt->max_count;
	114	}
	115
c3b92ce9	116	static int __init ramoops_probe(struct platform_device *pdev)
56d611a0	117	{
c3b92ce9	118	struct ramoops_platform_data *pdata = pdev->dev.platform_data;
56d611a0 MS	119	struct ramoops_context *cxt = &oops_cxt;
	120	int err = -EINVAL;
	121
3e5c4fad SI	122	if (!pdata->mem_size \|\| !pdata->record_size) {
	123	pr_err("The memory size and the record size must be "
	124	"non-zero\n");
56d611a0 MS	125	goto fail3;
	126	}
	127
13aefd72	128	rounddown_pow_of_two(pdata->mem_size);
3e5c4fad	129	rounddown_pow_of_two(pdata->record_size);
56d611a0	130
3e5c4fad SI	131	/* Check for the minimum memory size */
	132	if (pdata->mem_size < MIN_MEM_SIZE &&
	133	pdata->record_size < MIN_MEM_SIZE) {
	134	pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE);
56d611a0 MS	135	goto fail3;
	136	}
	137
3e5c4fad SI	138	if (pdata->mem_size < pdata->record_size) {
	139	pr_err("The memory size must be larger than the "
	140	"records size\n");
	141	goto fail3;
	142	}
	143
	144	cxt->max_count = pdata->mem_size / pdata->record_size;
56d611a0	145	cxt->count = 0;
13aefd72 MS	146	cxt->size = pdata->mem_size;
13aefd72 MS	147	cxt->phys_addr = pdata->mem_address;
3e5c4fad	148	cxt->record_size = pdata->record_size;
6b4d2a27	149	cxt->dump_oops = pdata->dump_oops;
f7b9fcbb SI	150	/*
	151	* Update the module parameter variables as well so they are visible
	152	* through /sys/module/ramoops/parameters/
	153	*/
	154	mem_size = pdata->mem_size;
	155	mem_address = pdata->mem_address;
	156	record_size = pdata->record_size;
	157	dump_oops = pdata->dump_oops;
56d611a0 MS	158
56d611a0 MS	159	if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
0169256e	160	pr_err("request mem region failed\n");
56d611a0 MS	161	err = -EINVAL;
	162	goto fail3;
	163	}
	164
	165	cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
	166	if (!cxt->virt_addr) {
0169256e	167	pr_err("ioremap failed\n");
56d611a0 MS	168	goto fail2;
	169	}
	170
	171	cxt->dump.dump = ramoops_do_dump;
	172	err = kmsg_dump_register(&cxt->dump);
	173	if (err) {
0169256e	174	pr_err("registering kmsg dumper failed\n");
56d611a0 MS	175	goto fail1;
	176	}
	177
	178	return 0;
	179
	180	fail1:
	181	iounmap(cxt->virt_addr);
	182	fail2:
	183	release_mem_region(cxt->phys_addr, cxt->size);
	184	fail3:
	185	return err;
	186	}
	187
c3b92ce9	188	static int __exit ramoops_remove(struct platform_device *pdev)
56d611a0 MS	189	{
	190	struct ramoops_context *cxt = &oops_cxt;
	191
	192	if (kmsg_dump_unregister(&cxt->dump) < 0)
0169256e	193	pr_warn("could not unregister kmsg_dumper\n");
56d611a0 MS	194
	195	iounmap(cxt->virt_addr);
	196	release_mem_region(cxt->phys_addr, cxt->size);
c3b92ce9	197	return 0;
56d611a0 MS	198	}
56d611a0 MS	199
c3b92ce9 KP	200	static struct platform_driver ramoops_driver = {
	201	.remove = __exit_p(ramoops_remove),
	202	.driver = {
	203	.name = "ramoops",
	204	.owner = THIS_MODULE,
	205	},
	206	};
	207
	208	static int __init ramoops_init(void)
	209	{
13aefd72 MS	210	int ret;
	211	ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
	212	if (ret == -ENODEV) {
	213	/*
	214	* If we didn't find a platform device, we use module parameters
	215	* building platform data on the fly.
	216	*/
0169256e	217	pr_info("platform device not found, using module parameters\n");
13aefd72 MS	218	dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
	219	GFP_KERNEL);
	220	if (!dummy_data)
	221	return -ENOMEM;
	222	dummy_data->mem_size = mem_size;
	223	dummy_data->mem_address = mem_address;
3e5c4fad	224	dummy_data->record_size = record_size;
6b4d2a27	225	dummy_data->dump_oops = dump_oops;
13aefd72 MS	226	dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
	227	NULL, 0, dummy_data,
	228	sizeof(struct ramoops_platform_data));
	229
	230	if (IS_ERR(dummy))
	231	ret = PTR_ERR(dummy);
	232	else
	233	ret = 0;
	234	}
	235
	236	return ret;
c3b92ce9 KP	237	}
	238
	239	static void __exit ramoops_exit(void)
	240	{
	241	platform_driver_unregister(&ramoops_driver);
13aefd72	242	kfree(dummy_data);
c3b92ce9	243	}
56d611a0 MS	244
	245	module_init(ramoops_init);
	246	module_exit(ramoops_exit);
	247
	248	MODULE_LICENSE("GPL");
	249	MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
	250	MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");