drivers/char/ramoops.c - maze/linux - Git at Google

 /*
  * 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");
	/*
	* 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");