2 * RAM Oops/Panic logger
4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
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.
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.
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
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/kmsg_dump.h>
25 #include <linux/time.h>
27 #include <linux/ioport.h>
28 #include <linux/platform_device.h>
29 #include <linux/ramoops.h>
31 #define RAMOOPS_KERNMSG_HDR "===="
33 #define RECORD_SIZE 4096
35 static ulong mem_address;
36 module_param(mem_address, ulong, 0400);
37 MODULE_PARM_DESC(mem_address,
38 "start of reserved RAM used to store oops/panic logs");
40 static ulong mem_size;
41 module_param(mem_size, ulong, 0400);
42 MODULE_PARM_DESC(mem_size,
43 "size of reserved RAM used to store oops/panic logs");
45 static int dump_oops = 1;
46 module_param(dump_oops, int, 0600);
47 MODULE_PARM_DESC(dump_oops,
48 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
50 static struct ramoops_context {
51 struct kmsg_dumper dump;
53 phys_addr_t phys_addr;
59 static void ramoops_do_dump(struct kmsg_dumper *dumper,
60 enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
61 const char *s2, unsigned long l2)
63 struct ramoops_context *cxt = container_of(dumper,
64 struct ramoops_context, dump);
65 unsigned long s1_start, s2_start;
66 unsigned long l1_cpy, l2_cpy;
69 struct timeval timestamp;
71 /* Only dump oopses if dump_oops is set */
72 if (reason == KMSG_DUMP_OOPS && !dump_oops)
75 buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE));
78 memset(buf, '\0', RECORD_SIZE);
79 res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
81 do_gettimeofday(×tamp);
82 res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
85 hdr_size = buf - buf_orig;
86 l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - hdr_size));
87 l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - hdr_size) - l2_cpy);
89 s2_start = l2 - l2_cpy;
90 s1_start = l1 - l1_cpy;
92 memcpy(buf, s1 + s1_start, l1_cpy);
93 memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
95 cxt->count = (cxt->count + 1) % cxt->max_count;
98 static int __init ramoops_probe(struct platform_device *pdev)
100 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
101 struct ramoops_context *cxt = &oops_cxt;
105 mem_size = pdata->mem_size;
106 mem_address = pdata->mem_address;
110 printk(KERN_ERR "ramoops: invalid size specification");
114 rounddown_pow_of_two(mem_size);
116 if (mem_size < RECORD_SIZE) {
117 printk(KERN_ERR "ramoops: size too small");
121 cxt->max_count = mem_size / RECORD_SIZE;
123 cxt->size = mem_size;
124 cxt->phys_addr = mem_address;
126 if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
127 printk(KERN_ERR "ramoops: request mem region failed");
132 cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
133 if (!cxt->virt_addr) {
134 printk(KERN_ERR "ramoops: ioremap failed");
138 cxt->dump.dump = ramoops_do_dump;
139 err = kmsg_dump_register(&cxt->dump);
141 printk(KERN_ERR "ramoops: registering kmsg dumper failed");
148 iounmap(cxt->virt_addr);
150 release_mem_region(cxt->phys_addr, cxt->size);
155 static int __exit ramoops_remove(struct platform_device *pdev)
157 struct ramoops_context *cxt = &oops_cxt;
159 if (kmsg_dump_unregister(&cxt->dump) < 0)
160 printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
162 iounmap(cxt->virt_addr);
163 release_mem_region(cxt->phys_addr, cxt->size);
167 static struct platform_driver ramoops_driver = {
168 .remove = __exit_p(ramoops_remove),
171 .owner = THIS_MODULE,
175 static int __init ramoops_init(void)
177 return platform_driver_probe(&ramoops_driver, ramoops_probe);
180 static void __exit ramoops_exit(void)
182 platform_driver_unregister(&ramoops_driver);
185 module_init(ramoops_init);
186 module_exit(ramoops_exit);
188 MODULE_LICENSE("GPL");
189 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
190 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");