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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/kmsg_dump.h>
27 #include <linux/time.h>
29 #include <linux/ioport.h>
30 #include <linux/platform_device.h>
31 #include <linux/slab.h>
32 #include <linux/ramoops.h>
34 #define RAMOOPS_KERNMSG_HDR "===="
35 #define MIN_MEM_SIZE 4096UL
37 static ulong record_size = MIN_MEM_SIZE;
38 module_param(record_size, ulong, 0400);
39 MODULE_PARM_DESC(record_size,
40 "size of each dump done on oops/panic");
42 static ulong mem_address;
43 module_param(mem_address, ulong, 0400);
44 MODULE_PARM_DESC(mem_address,
45 "start of reserved RAM used to store oops/panic logs");
47 static ulong mem_size;
48 module_param(mem_size, ulong, 0400);
49 MODULE_PARM_DESC(mem_size,
50 "size of reserved RAM used to store oops/panic logs");
52 static int dump_oops = 1;
53 module_param(dump_oops, int, 0600);
54 MODULE_PARM_DESC(dump_oops,
55 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
57 static struct ramoops_context {
58 struct kmsg_dumper dump;
60 phys_addr_t phys_addr;
62 unsigned long record_size;
68 static struct platform_device *dummy;
69 static struct ramoops_platform_data *dummy_data;
71 static void ramoops_do_dump(struct kmsg_dumper *dumper,
72 enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
73 const char *s2, unsigned long l2)
75 struct ramoops_context *cxt = container_of(dumper,
76 struct ramoops_context, dump);
77 unsigned long s1_start, s2_start;
78 unsigned long l1_cpy, l2_cpy;
81 struct timeval timestamp;
83 if (reason != KMSG_DUMP_OOPS &&
84 reason != KMSG_DUMP_PANIC &&
85 reason != KMSG_DUMP_KEXEC)
88 /* Only dump oopses if dump_oops is set */
89 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
92 buf = cxt->virt_addr + (cxt->count * cxt->record_size);
95 memset(buf, '\0', cxt->record_size);
96 res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
98 do_gettimeofday(×tamp);
99 res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
102 hdr_size = buf - buf_orig;
103 l2_cpy = min(l2, cxt->record_size - hdr_size);
104 l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy);
106 s2_start = l2 - l2_cpy;
107 s1_start = l1 - l1_cpy;
109 memcpy(buf, s1 + s1_start, l1_cpy);
110 memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
112 cxt->count = (cxt->count + 1) % cxt->max_count;
115 static int __init ramoops_probe(struct platform_device *pdev)
117 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
118 struct ramoops_context *cxt = &oops_cxt;
121 if (!pdata->mem_size || !pdata->record_size) {
122 pr_err("The memory size and the record size must be "
127 rounddown_pow_of_two(pdata->mem_size);
128 rounddown_pow_of_two(pdata->record_size);
130 /* Check for the minimum memory size */
131 if (pdata->mem_size < MIN_MEM_SIZE &&
132 pdata->record_size < MIN_MEM_SIZE) {
133 pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE);
137 if (pdata->mem_size < pdata->record_size) {
138 pr_err("The memory size must be larger than the "
143 cxt->max_count = pdata->mem_size / pdata->record_size;
145 cxt->size = pdata->mem_size;
146 cxt->phys_addr = pdata->mem_address;
147 cxt->record_size = pdata->record_size;
148 cxt->dump_oops = pdata->dump_oops;
150 if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
151 pr_err("request mem region failed\n");
156 cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
157 if (!cxt->virt_addr) {
158 pr_err("ioremap failed\n");
162 cxt->dump.dump = ramoops_do_dump;
163 err = kmsg_dump_register(&cxt->dump);
165 pr_err("registering kmsg dumper failed\n");
172 iounmap(cxt->virt_addr);
174 release_mem_region(cxt->phys_addr, cxt->size);
179 static int __exit ramoops_remove(struct platform_device *pdev)
181 struct ramoops_context *cxt = &oops_cxt;
183 if (kmsg_dump_unregister(&cxt->dump) < 0)
184 pr_warn("could not unregister kmsg_dumper\n");
186 iounmap(cxt->virt_addr);
187 release_mem_region(cxt->phys_addr, cxt->size);
191 static struct platform_driver ramoops_driver = {
192 .remove = __exit_p(ramoops_remove),
195 .owner = THIS_MODULE,
199 static int __init ramoops_init(void)
202 ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
203 if (ret == -ENODEV) {
205 * If we didn't find a platform device, we use module parameters
206 * building platform data on the fly.
208 pr_info("platform device not found, using module parameters\n");
209 dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
213 dummy_data->mem_size = mem_size;
214 dummy_data->mem_address = mem_address;
215 dummy_data->record_size = record_size;
216 dummy_data->dump_oops = dump_oops;
217 dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
219 sizeof(struct ramoops_platform_data));
222 ret = PTR_ERR(dummy);
230 static void __exit ramoops_exit(void)
232 platform_driver_unregister(&ramoops_driver);
236 module_init(ramoops_init);
237 module_exit(ramoops_exit);
239 MODULE_LICENSE("GPL");
240 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
241 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");