diff options
Diffstat (limited to 'drivers/char/ramoops.c')
| -rw-r--r-- | drivers/char/ramoops.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c new file mode 100644 index 000000000000..74f00b5ffa36 --- /dev/null +++ b/drivers/char/ramoops.c @@ -0,0 +1,162 @@ +/* + * 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> + +#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_init(void) +{ + struct ramoops_context *cxt = &oops_cxt; + int err = -EINVAL; + + 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 void __exit ramoops_exit(void) +{ + 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); +} + + +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"); |