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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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
23 | ||
24 | #include <linux/kernel.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/kmsg_dump.h> | |
27 | #include <linux/time.h> | |
28 | #include <linux/io.h> | |
29 | #include <linux/ioport.h> | |
30 | #include <linux/platform_device.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/ramoops.h> | |
33 | ||
34 | #define RAMOOPS_KERNMSG_HDR "====" | |
35 | ||
36 | #define RECORD_SIZE 4096UL | |
37 | ||
38 | static ulong mem_address; | |
39 | module_param(mem_address, ulong, 0400); | |
40 | MODULE_PARM_DESC(mem_address, | |
41 | "start of reserved RAM used to store oops/panic logs"); | |
42 | ||
43 | static ulong mem_size; | |
44 | module_param(mem_size, ulong, 0400); | |
45 | MODULE_PARM_DESC(mem_size, | |
46 | "size of reserved RAM used to store oops/panic logs"); | |
47 | ||
48 | static int dump_oops = 1; | |
49 | module_param(dump_oops, int, 0600); | |
50 | MODULE_PARM_DESC(dump_oops, | |
51 | "set to 1 to dump oopses, 0 to only dump panics (default 1)"); | |
52 | ||
53 | static struct ramoops_context { | |
54 | struct kmsg_dumper dump; | |
55 | void *virt_addr; | |
56 | phys_addr_t phys_addr; | |
57 | unsigned long size; | |
58 | int dump_oops; | |
59 | int count; | |
60 | int max_count; | |
61 | } oops_cxt; | |
62 | ||
63 | static struct platform_device *dummy; | |
64 | static struct ramoops_platform_data *dummy_data; | |
65 | ||
66 | static void ramoops_do_dump(struct kmsg_dumper *dumper, | |
67 | enum kmsg_dump_reason reason, const char *s1, unsigned long l1, | |
68 | const char *s2, unsigned long l2) | |
69 | { | |
70 | struct ramoops_context *cxt = container_of(dumper, | |
71 | struct ramoops_context, dump); | |
72 | unsigned long s1_start, s2_start; | |
73 | unsigned long l1_cpy, l2_cpy; | |
74 | int res, hdr_size; | |
75 | char *buf, *buf_orig; | |
76 | struct timeval timestamp; | |
77 | ||
78 | if (reason != KMSG_DUMP_OOPS && | |
79 | reason != KMSG_DUMP_PANIC && | |
80 | reason != KMSG_DUMP_KEXEC) | |
81 | return; | |
82 | ||
83 | /* Only dump oopses if dump_oops is set */ | |
84 | if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops) | |
85 | return; | |
86 | ||
87 | buf = cxt->virt_addr + (cxt->count * RECORD_SIZE); | |
88 | buf_orig = buf; | |
89 | ||
90 | memset(buf, '\0', RECORD_SIZE); | |
91 | res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR); | |
92 | buf += res; | |
93 | do_gettimeofday(×tamp); | |
94 | res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec); | |
95 | buf += res; | |
96 | ||
97 | hdr_size = buf - buf_orig; | |
98 | l2_cpy = min(l2, RECORD_SIZE - hdr_size); | |
99 | l1_cpy = min(l1, RECORD_SIZE - hdr_size - l2_cpy); | |
100 | ||
101 | s2_start = l2 - l2_cpy; | |
102 | s1_start = l1 - l1_cpy; | |
103 | ||
104 | memcpy(buf, s1 + s1_start, l1_cpy); | |
105 | memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy); | |
106 | ||
107 | cxt->count = (cxt->count + 1) % cxt->max_count; | |
108 | } | |
109 | ||
110 | static int __init ramoops_probe(struct platform_device *pdev) | |
111 | { | |
112 | struct ramoops_platform_data *pdata = pdev->dev.platform_data; | |
113 | struct ramoops_context *cxt = &oops_cxt; | |
114 | int err = -EINVAL; | |
115 | ||
116 | if (!pdata->mem_size) { | |
117 | pr_err("invalid size specification\n"); | |
118 | goto fail3; | |
119 | } | |
120 | ||
121 | rounddown_pow_of_two(pdata->mem_size); | |
122 | ||
123 | if (pdata->mem_size < RECORD_SIZE) { | |
124 | pr_err("size too small\n"); | |
125 | goto fail3; | |
126 | } | |
127 | ||
128 | cxt->max_count = pdata->mem_size / RECORD_SIZE; | |
129 | cxt->count = 0; | |
130 | cxt->size = pdata->mem_size; | |
131 | cxt->phys_addr = pdata->mem_address; | |
132 | cxt->dump_oops = pdata->dump_oops; | |
133 | ||
134 | if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) { | |
135 | pr_err("request mem region failed\n"); | |
136 | err = -EINVAL; | |
137 | goto fail3; | |
138 | } | |
139 | ||
140 | cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size); | |
141 | if (!cxt->virt_addr) { | |
142 | pr_err("ioremap failed\n"); | |
143 | goto fail2; | |
144 | } | |
145 | ||
146 | cxt->dump.dump = ramoops_do_dump; | |
147 | err = kmsg_dump_register(&cxt->dump); | |
148 | if (err) { | |
149 | pr_err("registering kmsg dumper failed\n"); | |
150 | goto fail1; | |
151 | } | |
152 | ||
153 | return 0; | |
154 | ||
155 | fail1: | |
156 | iounmap(cxt->virt_addr); | |
157 | fail2: | |
158 | release_mem_region(cxt->phys_addr, cxt->size); | |
159 | fail3: | |
160 | return err; | |
161 | } | |
162 | ||
163 | static int __exit ramoops_remove(struct platform_device *pdev) | |
164 | { | |
165 | struct ramoops_context *cxt = &oops_cxt; | |
166 | ||
167 | if (kmsg_dump_unregister(&cxt->dump) < 0) | |
168 | pr_warn("could not unregister kmsg_dumper\n"); | |
169 | ||
170 | iounmap(cxt->virt_addr); | |
171 | release_mem_region(cxt->phys_addr, cxt->size); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | static struct platform_driver ramoops_driver = { | |
176 | .remove = __exit_p(ramoops_remove), | |
177 | .driver = { | |
178 | .name = "ramoops", | |
179 | .owner = THIS_MODULE, | |
180 | }, | |
181 | }; | |
182 | ||
183 | static int __init ramoops_init(void) | |
184 | { | |
185 | int ret; | |
186 | ret = platform_driver_probe(&ramoops_driver, ramoops_probe); | |
187 | if (ret == -ENODEV) { | |
188 | /* | |
189 | * If we didn't find a platform device, we use module parameters | |
190 | * building platform data on the fly. | |
191 | */ | |
192 | pr_info("platform device not found, using module parameters\n"); | |
193 | dummy_data = kzalloc(sizeof(struct ramoops_platform_data), | |
194 | GFP_KERNEL); | |
195 | if (!dummy_data) | |
196 | return -ENOMEM; | |
197 | dummy_data->mem_size = mem_size; | |
198 | dummy_data->mem_address = mem_address; | |
199 | dummy_data->dump_oops = dump_oops; | |
200 | dummy = platform_create_bundle(&ramoops_driver, ramoops_probe, | |
201 | NULL, 0, dummy_data, | |
202 | sizeof(struct ramoops_platform_data)); | |
203 | ||
204 | if (IS_ERR(dummy)) | |
205 | ret = PTR_ERR(dummy); | |
206 | else | |
207 | ret = 0; | |
208 | } | |
209 | ||
210 | return ret; | |
211 | } | |
212 | ||
213 | static void __exit ramoops_exit(void) | |
214 | { | |
215 | platform_driver_unregister(&ramoops_driver); | |
216 | kfree(dummy_data); | |
217 | } | |
218 | ||
219 | module_init(ramoops_init); | |
220 | module_exit(ramoops_exit); | |
221 | ||
222 | MODULE_LICENSE("GPL"); | |
223 | MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>"); | |
224 | MODULE_DESCRIPTION("RAM Oops/Panic logger/driver"); |