1/* 2 * RAM Oops/Panic logger 3 * 4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * version 2 as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 18 * 02110-1301 USA 19 * 20 */ 21 22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 23 24#include <linux/kernel.h> 25#include <linux/err.h> 26#include <linux/module.h> 27#include <linux/kmsg_dump.h> 28#include <linux/time.h> 29#include <linux/err.h> 30#include <linux/io.h> 31#include <linux/ioport.h> 32#include <linux/platform_device.h> 33#include <linux/slab.h> 34#include <linux/ramoops.h> 35 36#define RAMOOPS_KERNMSG_HDR "====" 37#define MIN_MEM_SIZE 4096UL 38 39static ulong record_size = MIN_MEM_SIZE; 40module_param(record_size, ulong, 0400); 41MODULE_PARM_DESC(record_size, 42 "size of each dump done on oops/panic"); 43 44static ulong mem_address; 45module_param(mem_address, ulong, 0400); 46MODULE_PARM_DESC(mem_address, 47 "start of reserved RAM used to store oops/panic logs"); 48 49static ulong mem_size; 50module_param(mem_size, ulong, 0400); 51MODULE_PARM_DESC(mem_size, 52 "size of reserved RAM used to store oops/panic logs"); 53 54static int dump_oops = 1; 55module_param(dump_oops, int, 0600); 56MODULE_PARM_DESC(dump_oops, 57 "set to 1 to dump oopses, 0 to only dump panics (default 1)"); 58 59static struct ramoops_context { 60 struct kmsg_dumper dump; 61 void *virt_addr; 62 phys_addr_t phys_addr; 63 unsigned long size; 64 unsigned long record_size; 65 int dump_oops; 66 int count; 67 int max_count; 68} oops_cxt; 69 70static struct platform_device *dummy; 71static struct ramoops_platform_data *dummy_data; 72 73static void ramoops_do_dump(struct kmsg_dumper *dumper, 74 enum kmsg_dump_reason reason, const char *s1, unsigned long l1, 75 const char *s2, unsigned long l2) 76{ 77 struct ramoops_context *cxt = container_of(dumper, 78 struct ramoops_context, dump); 79 unsigned long s1_start, s2_start; 80 unsigned long l1_cpy, l2_cpy; 81 int res, hdr_size; 82 char *buf, *buf_orig; 83 struct timeval timestamp; 84 85 if (reason != KMSG_DUMP_OOPS && 86 reason != KMSG_DUMP_PANIC) 87 return; 88 89 /* Only dump oopses if dump_oops is set */ 90 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops) 91 return; 92 93 buf = cxt->virt_addr + (cxt->count * cxt->record_size); 94 buf_orig = buf; 95 96 memset(buf, '\0', cxt->record_size); 97 res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR); 98 buf += res; 99 do_gettimeofday(×tamp); 100 res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec); 101 buf += res; 102 103 hdr_size = buf - buf_orig; 104 l2_cpy = min(l2, cxt->record_size - hdr_size); 105 l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy); 106 107 s2_start = l2 - l2_cpy; 108 s1_start = l1 - l1_cpy; 109 110 memcpy(buf, s1 + s1_start, l1_cpy); 111 memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy); 112 113 cxt->count = (cxt->count + 1) % cxt->max_count; 114} 115 116static int __init ramoops_probe(struct platform_device *pdev) 117{ 118 struct ramoops_platform_data *pdata = pdev->dev.platform_data; 119 struct ramoops_context *cxt = &oops_cxt; 120 int err = -EINVAL; 121 122 if (!pdata->mem_size || !pdata->record_size) { 123 pr_err("The memory size and the record size must be " 124 "non-zero\n"); 125 goto fail3; 126 } 127 128 pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); 129 pdata->record_size = rounddown_pow_of_two(pdata->record_size); 130 131 /* Check for the minimum memory size */ 132 if (pdata->mem_size < MIN_MEM_SIZE && 133 pdata->record_size < MIN_MEM_SIZE) { 134 pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE); 135 goto fail3; 136 } 137 138 if (pdata->mem_size < pdata->record_size) { 139 pr_err("The memory size must be larger than the " 140 "records size\n"); 141 goto fail3; 142 } 143 144 cxt->max_count = pdata->mem_size / pdata->record_size; 145 cxt->count = 0; 146 cxt->size = pdata->mem_size; 147 cxt->phys_addr = pdata->mem_address; 148 cxt->record_size = pdata->record_size; 149 cxt->dump_oops = pdata->dump_oops; 150 151 if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) { 152 pr_err("request mem region failed\n"); 153 err = -EINVAL; 154 goto fail3; 155 } 156 157 cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size); 158 if (!cxt->virt_addr) { 159 pr_err("ioremap failed\n"); 160 goto fail2; 161 } 162 163 cxt->dump.dump = ramoops_do_dump; 164 err = kmsg_dump_register(&cxt->dump); 165 if (err) { 166 pr_err("registering kmsg dumper failed\n"); 167 goto fail1; 168 } 169 170 /* 171 * Update the module parameter variables as well so they are visible 172 * through /sys/module/ramoops/parameters/ 173 */ 174 mem_size = pdata->mem_size; 175 mem_address = pdata->mem_address; 176 record_size = pdata->record_size; 177 dump_oops = pdata->dump_oops; 178 179 return 0; 180 181fail1: 182 iounmap(cxt->virt_addr); 183fail2: 184 release_mem_region(cxt->phys_addr, cxt->size); 185fail3: 186 return err; 187} 188 189static int __exit ramoops_remove(struct platform_device *pdev) 190{ 191 struct ramoops_context *cxt = &oops_cxt; 192 193 if (kmsg_dump_unregister(&cxt->dump) < 0) 194 pr_warn("could not unregister kmsg_dumper\n"); 195 196 iounmap(cxt->virt_addr); 197 release_mem_region(cxt->phys_addr, cxt->size); 198 return 0; 199} 200 201static struct platform_driver ramoops_driver = { 202 .remove = __exit_p(ramoops_remove), 203 .driver = { 204 .name = "ramoops", 205 .owner = THIS_MODULE, 206 }, 207}; 208 209static int __init ramoops_init(void) 210{ 211 int ret; 212 ret = platform_driver_probe(&ramoops_driver, ramoops_probe); 213 if (ret == -ENODEV) { 214 /* 215 * If we didn't find a platform device, we use module parameters 216 * building platform data on the fly. 217 */ 218 pr_info("platform device not found, using module parameters\n"); 219 dummy_data = kzalloc(sizeof(struct ramoops_platform_data), 220 GFP_KERNEL); 221 if (!dummy_data) 222 return -ENOMEM; 223 dummy_data->mem_size = mem_size; 224 dummy_data->mem_address = mem_address; 225 dummy_data->record_size = record_size; 226 dummy_data->dump_oops = dump_oops; 227 dummy = platform_create_bundle(&ramoops_driver, ramoops_probe, 228 NULL, 0, dummy_data, 229 sizeof(struct ramoops_platform_data)); 230 231 if (IS_ERR(dummy)) 232 ret = PTR_ERR(dummy); 233 else 234 ret = 0; 235 } 236 237 return ret; 238} 239 240static void __exit ramoops_exit(void) 241{ 242 platform_driver_unregister(&ramoops_driver); 243 kfree(dummy_data); 244} 245 246module_init(ramoops_init); 247module_exit(ramoops_exit); 248 249MODULE_LICENSE("GPL"); 250MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>"); 251MODULE_DESCRIPTION("RAM Oops/Panic logger/driver"); 252