Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/kmsg_dump.h>
25#include <linux/time.h>
26#include <linux/io.h>
27#include <linux/ioport.h>
28#include <linux/platform_device.h>
29#include <linux/ramoops.h>
30
31#define RAMOOPS_KERNMSG_HDR "===="
32
33#define RECORD_SIZE 4096UL
34
35static ulong mem_address;
36module_param(mem_address, ulong, 0400);
37MODULE_PARM_DESC(mem_address,
38 "start of reserved RAM used to store oops/panic logs");
39
40static ulong mem_size;
41module_param(mem_size, ulong, 0400);
42MODULE_PARM_DESC(mem_size,
43 "size of reserved RAM used to store oops/panic logs");
44
45static int dump_oops = 1;
46module_param(dump_oops, int, 0600);
47MODULE_PARM_DESC(dump_oops,
48 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
49
50static struct ramoops_context {
51 struct kmsg_dumper dump;
52 void *virt_addr;
53 phys_addr_t phys_addr;
54 unsigned long size;
55 int count;
56 int max_count;
57} oops_cxt;
58
59static 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)
62{
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;
67 int res, hdr_size;
68 char *buf, *buf_orig;
69 struct timeval timestamp;
70
71 if (reason != KMSG_DUMP_OOPS &&
72 reason != KMSG_DUMP_PANIC &&
73 reason != KMSG_DUMP_KEXEC)
74 return;
75
76 /* Only dump oopses if dump_oops is set */
77 if (reason == KMSG_DUMP_OOPS && !dump_oops)
78 return;
79
80 buf = cxt->virt_addr + (cxt->count * RECORD_SIZE);
81 buf_orig = buf;
82
83 memset(buf, '\0', RECORD_SIZE);
84 res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
85 buf += res;
86 do_gettimeofday(×tamp);
87 res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
88 buf += res;
89
90 hdr_size = buf - buf_orig;
91 l2_cpy = min(l2, RECORD_SIZE - hdr_size);
92 l1_cpy = min(l1, RECORD_SIZE - hdr_size - l2_cpy);
93
94 s2_start = l2 - l2_cpy;
95 s1_start = l1 - l1_cpy;
96
97 memcpy(buf, s1 + s1_start, l1_cpy);
98 memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
99
100 cxt->count = (cxt->count + 1) % cxt->max_count;
101}
102
103static int __init ramoops_probe(struct platform_device *pdev)
104{
105 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
106 struct ramoops_context *cxt = &oops_cxt;
107 int err = -EINVAL;
108
109 if (pdata) {
110 mem_size = pdata->mem_size;
111 mem_address = pdata->mem_address;
112 }
113
114 if (!mem_size) {
115 printk(KERN_ERR "ramoops: invalid size specification");
116 goto fail3;
117 }
118
119 rounddown_pow_of_two(mem_size);
120
121 if (mem_size < RECORD_SIZE) {
122 printk(KERN_ERR "ramoops: size too small");
123 goto fail3;
124 }
125
126 cxt->max_count = mem_size / RECORD_SIZE;
127 cxt->count = 0;
128 cxt->size = mem_size;
129 cxt->phys_addr = mem_address;
130
131 if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
132 printk(KERN_ERR "ramoops: request mem region failed");
133 err = -EINVAL;
134 goto fail3;
135 }
136
137 cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
138 if (!cxt->virt_addr) {
139 printk(KERN_ERR "ramoops: ioremap failed");
140 goto fail2;
141 }
142
143 cxt->dump.dump = ramoops_do_dump;
144 err = kmsg_dump_register(&cxt->dump);
145 if (err) {
146 printk(KERN_ERR "ramoops: registering kmsg dumper failed");
147 goto fail1;
148 }
149
150 return 0;
151
152fail1:
153 iounmap(cxt->virt_addr);
154fail2:
155 release_mem_region(cxt->phys_addr, cxt->size);
156fail3:
157 return err;
158}
159
160static int __exit ramoops_remove(struct platform_device *pdev)
161{
162 struct ramoops_context *cxt = &oops_cxt;
163
164 if (kmsg_dump_unregister(&cxt->dump) < 0)
165 printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
166
167 iounmap(cxt->virt_addr);
168 release_mem_region(cxt->phys_addr, cxt->size);
169 return 0;
170}
171
172static struct platform_driver ramoops_driver = {
173 .remove = __exit_p(ramoops_remove),
174 .driver = {
175 .name = "ramoops",
176 .owner = THIS_MODULE,
177 },
178};
179
180static int __init ramoops_init(void)
181{
182 return platform_driver_probe(&ramoops_driver, ramoops_probe);
183}
184
185static void __exit ramoops_exit(void)
186{
187 platform_driver_unregister(&ramoops_driver);
188}
189
190module_init(ramoops_init);
191module_exit(ramoops_exit);
192
193MODULE_LICENSE("GPL");
194MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
195MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");