/* * 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 RAMOOPS_HEADER_SIZE (5 + sizeof(struct timeval)) #define RECORD_SIZE 4096 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; char *buf; struct timeval timestamp; /* Only dump oopses if dump_oops is set */ if (reason == KMSG_DUMP_OOPS && !dump_oops) return; buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE)); memset(buf, '\0', RECORD_SIZE); res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR); buf += res; do_gettimeofday(×tamp); res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec); buf += res; l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE)); l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_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");