/* * 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 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 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, 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 && !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 = 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");