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/err.h>
26
#include <linux/module.h>
27
#include <linux/kmsg_dump.h>
28
#include <linux/time.h>
29
#include <linux/err.h>
31
#include <linux/ioport.h>
32
#include <linux/platform_device.h>
33
#include <linux/slab.h>
34
#include <linux/ramoops.h>
36
#define RAMOOPS_KERNMSG_HDR "===="
37
#define MIN_MEM_SIZE 4096UL
39
static ulong record_size = MIN_MEM_SIZE;
40
module_param(record_size, ulong, 0400);
41
MODULE_PARM_DESC(record_size,
42
"size of each dump done on oops/panic");
44
static ulong mem_address;
45
module_param(mem_address, ulong, 0400);
46
MODULE_PARM_DESC(mem_address,
47
"start of reserved RAM used to store oops/panic logs");
49
static ulong mem_size;
50
module_param(mem_size, ulong, 0400);
51
MODULE_PARM_DESC(mem_size,
52
"size of reserved RAM used to store oops/panic logs");
54
static int dump_oops = 1;
55
module_param(dump_oops, int, 0600);
56
MODULE_PARM_DESC(dump_oops,
57
"set to 1 to dump oopses, 0 to only dump panics (default 1)");
59
static struct ramoops_context {
60
struct kmsg_dumper dump;
62
phys_addr_t phys_addr;
64
unsigned long record_size;
70
static struct platform_device *dummy;
71
static struct ramoops_platform_data *dummy_data;
73
static 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)
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;
83
struct timeval timestamp;
85
if (reason != KMSG_DUMP_OOPS &&
86
reason != KMSG_DUMP_PANIC &&
87
reason != KMSG_DUMP_KEXEC)
90
/* Only dump oopses if dump_oops is set */
91
if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
94
buf = cxt->virt_addr + (cxt->count * cxt->record_size);
97
memset(buf, '\0', cxt->record_size);
98
res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
100
do_gettimeofday(×tamp);
101
res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
104
hdr_size = buf - buf_orig;
105
l2_cpy = min(l2, cxt->record_size - hdr_size);
106
l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy);
108
s2_start = l2 - l2_cpy;
109
s1_start = l1 - l1_cpy;
111
memcpy(buf, s1 + s1_start, l1_cpy);
112
memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
114
cxt->count = (cxt->count + 1) % cxt->max_count;
117
static int __init ramoops_probe(struct platform_device *pdev)
119
struct ramoops_platform_data *pdata = pdev->dev.platform_data;
120
struct ramoops_context *cxt = &oops_cxt;
123
if (!pdata->mem_size || !pdata->record_size) {
124
pr_err("The memory size and the record size must be "
129
rounddown_pow_of_two(pdata->mem_size);
130
rounddown_pow_of_two(pdata->record_size);
132
/* Check for the minimum memory size */
133
if (pdata->mem_size < MIN_MEM_SIZE &&
134
pdata->record_size < MIN_MEM_SIZE) {
135
pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE);
139
if (pdata->mem_size < pdata->record_size) {
140
pr_err("The memory size must be larger than the "
145
cxt->max_count = pdata->mem_size / pdata->record_size;
147
cxt->size = pdata->mem_size;
148
cxt->phys_addr = pdata->mem_address;
149
cxt->record_size = pdata->record_size;
150
cxt->dump_oops = pdata->dump_oops;
152
* Update the module parameter variables as well so they are visible
153
* through /sys/module/ramoops/parameters/
155
mem_size = pdata->mem_size;
156
mem_address = pdata->mem_address;
157
record_size = pdata->record_size;
158
dump_oops = pdata->dump_oops;
160
if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
161
pr_err("request mem region failed\n");
166
cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
167
if (!cxt->virt_addr) {
168
pr_err("ioremap failed\n");
172
cxt->dump.dump = ramoops_do_dump;
173
err = kmsg_dump_register(&cxt->dump);
175
pr_err("registering kmsg dumper failed\n");
182
iounmap(cxt->virt_addr);
184
release_mem_region(cxt->phys_addr, cxt->size);
189
static int __exit ramoops_remove(struct platform_device *pdev)
191
struct ramoops_context *cxt = &oops_cxt;
193
if (kmsg_dump_unregister(&cxt->dump) < 0)
194
pr_warn("could not unregister kmsg_dumper\n");
196
iounmap(cxt->virt_addr);
197
release_mem_region(cxt->phys_addr, cxt->size);
201
static struct platform_driver ramoops_driver = {
202
.remove = __exit_p(ramoops_remove),
205
.owner = THIS_MODULE,
209
static int __init ramoops_init(void)
212
ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
213
if (ret == -ENODEV) {
215
* If we didn't find a platform device, we use module parameters
216
* building platform data on the fly.
218
pr_info("platform device not found, using module parameters\n");
219
dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
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,
229
sizeof(struct ramoops_platform_data));
232
ret = PTR_ERR(dummy);
240
static void __exit ramoops_exit(void)
242
platform_driver_unregister(&ramoops_driver);
246
module_init(ramoops_init);
247
module_exit(ramoops_exit);
249
MODULE_LICENSE("GPL");
250
MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
251
MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");