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/slab.h>
30 #include <linux/ramoops.h>
32 #define RAMOOPS_KERNMSG_HDR "===="
34 #define RECORD_SIZE 4096UL
36 static ulong mem_address
;
37 module_param(mem_address
, ulong
, 0400);
38 MODULE_PARM_DESC(mem_address
,
39 "start of reserved RAM used to store oops/panic logs");
41 static ulong mem_size
;
42 module_param(mem_size
, ulong
, 0400);
43 MODULE_PARM_DESC(mem_size
,
44 "size of reserved RAM used to store oops/panic logs");
46 static int dump_oops
= 1;
47 module_param(dump_oops
, int, 0600);
48 MODULE_PARM_DESC(dump_oops
,
49 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
51 static struct ramoops_context
{
52 struct kmsg_dumper dump
;
54 phys_addr_t phys_addr
;
60 static struct platform_device
*dummy
;
61 static struct ramoops_platform_data
*dummy_data
;
63 static void ramoops_do_dump(struct kmsg_dumper
*dumper
,
64 enum kmsg_dump_reason reason
, const char *s1
, unsigned long l1
,
65 const char *s2
, unsigned long l2
)
67 struct ramoops_context
*cxt
= container_of(dumper
,
68 struct ramoops_context
, dump
);
69 unsigned long s1_start
, s2_start
;
70 unsigned long l1_cpy
, l2_cpy
;
73 struct timeval timestamp
;
75 if (reason
!= KMSG_DUMP_OOPS
&&
76 reason
!= KMSG_DUMP_PANIC
&&
77 reason
!= KMSG_DUMP_KEXEC
)
80 /* Only dump oopses if dump_oops is set */
81 if (reason
== KMSG_DUMP_OOPS
&& !dump_oops
)
84 buf
= cxt
->virt_addr
+ (cxt
->count
* RECORD_SIZE
);
87 memset(buf
, '\0', RECORD_SIZE
);
88 res
= sprintf(buf
, "%s", RAMOOPS_KERNMSG_HDR
);
90 do_gettimeofday(×tamp
);
91 res
= sprintf(buf
, "%lu.%lu\n", (long)timestamp
.tv_sec
, (long)timestamp
.tv_usec
);
94 hdr_size
= buf
- buf_orig
;
95 l2_cpy
= min(l2
, RECORD_SIZE
- hdr_size
);
96 l1_cpy
= min(l1
, RECORD_SIZE
- hdr_size
- l2_cpy
);
98 s2_start
= l2
- l2_cpy
;
99 s1_start
= l1
- l1_cpy
;
101 memcpy(buf
, s1
+ s1_start
, l1_cpy
);
102 memcpy(buf
+ l1_cpy
, s2
+ s2_start
, l2_cpy
);
104 cxt
->count
= (cxt
->count
+ 1) % cxt
->max_count
;
107 static int __init
ramoops_probe(struct platform_device
*pdev
)
109 struct ramoops_platform_data
*pdata
= pdev
->dev
.platform_data
;
110 struct ramoops_context
*cxt
= &oops_cxt
;
113 if (!pdata
->mem_size
) {
114 printk(KERN_ERR
"ramoops: invalid size specification");
118 rounddown_pow_of_two(pdata
->mem_size
);
120 if (pdata
->mem_size
< RECORD_SIZE
) {
121 printk(KERN_ERR
"ramoops: size too small");
125 cxt
->max_count
= pdata
->mem_size
/ RECORD_SIZE
;
127 cxt
->size
= pdata
->mem_size
;
128 cxt
->phys_addr
= pdata
->mem_address
;
130 if (!request_mem_region(cxt
->phys_addr
, cxt
->size
, "ramoops")) {
131 printk(KERN_ERR
"ramoops: request mem region failed");
136 cxt
->virt_addr
= ioremap(cxt
->phys_addr
, cxt
->size
);
137 if (!cxt
->virt_addr
) {
138 printk(KERN_ERR
"ramoops: ioremap failed");
142 cxt
->dump
.dump
= ramoops_do_dump
;
143 err
= kmsg_dump_register(&cxt
->dump
);
145 printk(KERN_ERR
"ramoops: registering kmsg dumper failed");
152 iounmap(cxt
->virt_addr
);
154 release_mem_region(cxt
->phys_addr
, cxt
->size
);
159 static int __exit
ramoops_remove(struct platform_device
*pdev
)
161 struct ramoops_context
*cxt
= &oops_cxt
;
163 if (kmsg_dump_unregister(&cxt
->dump
) < 0)
164 printk(KERN_WARNING
"ramoops: could not unregister kmsg_dumper");
166 iounmap(cxt
->virt_addr
);
167 release_mem_region(cxt
->phys_addr
, cxt
->size
);
171 static struct platform_driver ramoops_driver
= {
172 .remove
= __exit_p(ramoops_remove
),
175 .owner
= THIS_MODULE
,
179 static int __init
ramoops_init(void)
182 ret
= platform_driver_probe(&ramoops_driver
, ramoops_probe
);
183 if (ret
== -ENODEV
) {
185 * If we didn't find a platform device, we use module parameters
186 * building platform data on the fly.
188 dummy_data
= kzalloc(sizeof(struct ramoops_platform_data
),
192 dummy_data
->mem_size
= mem_size
;
193 dummy_data
->mem_address
= mem_address
;
194 dummy
= platform_create_bundle(&ramoops_driver
, ramoops_probe
,
196 sizeof(struct ramoops_platform_data
));
199 ret
= PTR_ERR(dummy
);
207 static void __exit
ramoops_exit(void)
209 platform_driver_unregister(&ramoops_driver
);
213 module_init(ramoops_init
);
214 module_exit(ramoops_exit
);
216 MODULE_LICENSE("GPL");
217 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
218 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");