diff options
Diffstat (limited to 'drivers/char/ramoops.c')
| -rw-r--r-- | drivers/char/ramoops.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c new file mode 100644 index 00000000..2a5e45d2 --- /dev/null +++ b/drivers/char/ramoops.c @@ -0,0 +1,250 @@ +/* + * 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/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(×tamp); + 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; + } + + pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); + pdata->record_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; + } + + /* + * 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; + + 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"); |