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/err.h>
26 #include <linux/module.h>
27 #include <linux/kmsg_dump.h>
28 #include <linux/time.h>
29 #include <linux/err.h>
30 #include <linux/io.h>
31 #include <linux/ioport.h>
32 #include <linux/platform_device.h>
33 #include <linux/slab.h>
34 #include <linux/ramoops.h>
35
36 #define RAMOOPS_KERNMSG_HDR "===="
37 #define MIN_MEM_SIZE 4096UL
38
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");
43
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");
48
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");
53
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)");
58
59 static struct ramoops_context {
60 struct kmsg_dumper dump;
61 void *virt_addr;
62 phys_addr_t phys_addr;
63 unsigned long size;
64 unsigned long record_size;
65 int dump_oops;
66 int count;
67 int max_count;
68 } oops_cxt;
69
70 static struct platform_device *dummy;
71 static struct ramoops_platform_data *dummy_data;
72
ramoops_do_dump(struct kmsg_dumper * dumper,enum kmsg_dump_reason reason,const char * s1,unsigned long l1,const char * s2,unsigned long l2)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)
76 {
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;
81 int res, hdr_size;
82 char *buf, *buf_orig;
83 struct timeval timestamp;
84
85 if (reason != KMSG_DUMP_OOPS &&
86 reason != KMSG_DUMP_PANIC)
87 return;
88
89 /* Only dump oopses if dump_oops is set */
90 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
91 return;
92
93 buf = cxt->virt_addr + (cxt->count * cxt->record_size);
94 buf_orig = buf;
95
96 memset(buf, '\0', cxt->record_size);
97 res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
98 buf += res;
99 do_gettimeofday(×tamp);
100 res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
101 buf += res;
102
103 hdr_size = buf - buf_orig;
104 l2_cpy = min(l2, cxt->record_size - hdr_size);
105 l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy);
106
107 s2_start = l2 - l2_cpy;
108 s1_start = l1 - l1_cpy;
109
110 memcpy(buf, s1 + s1_start, l1_cpy);
111 memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
112
113 cxt->count = (cxt->count + 1) % cxt->max_count;
114 }
115
ramoops_probe(struct platform_device * pdev)116 static int __init ramoops_probe(struct platform_device *pdev)
117 {
118 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
119 struct ramoops_context *cxt = &oops_cxt;
120 int err = -EINVAL;
121
122 if (!pdata->mem_size || !pdata->record_size) {
123 pr_err("The memory size and the record size must be "
124 "non-zero\n");
125 goto fail3;
126 }
127
128 pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
129 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
130
131 /* Check for the minimum memory size */
132 if (pdata->mem_size < MIN_MEM_SIZE &&
133 pdata->record_size < MIN_MEM_SIZE) {
134 pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE);
135 goto fail3;
136 }
137
138 if (pdata->mem_size < pdata->record_size) {
139 pr_err("The memory size must be larger than the "
140 "records size\n");
141 goto fail3;
142 }
143
144 cxt->max_count = pdata->mem_size / pdata->record_size;
145 cxt->count = 0;
146 cxt->size = pdata->mem_size;
147 cxt->phys_addr = pdata->mem_address;
148 cxt->record_size = pdata->record_size;
149 cxt->dump_oops = pdata->dump_oops;
150
151 if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
152 pr_err("request mem region failed\n");
153 err = -EINVAL;
154 goto fail3;
155 }
156
157 cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
158 if (!cxt->virt_addr) {
159 pr_err("ioremap failed\n");
160 goto fail2;
161 }
162
163 cxt->dump.dump = ramoops_do_dump;
164 err = kmsg_dump_register(&cxt->dump);
165 if (err) {
166 pr_err("registering kmsg dumper failed\n");
167 goto fail1;
168 }
169
170 /*
171 * Update the module parameter variables as well so they are visible
172 * through /sys/module/ramoops/parameters/
173 */
174 mem_size = pdata->mem_size;
175 mem_address = pdata->mem_address;
176 record_size = pdata->record_size;
177 dump_oops = pdata->dump_oops;
178
179 return 0;
180
181 fail1:
182 iounmap(cxt->virt_addr);
183 fail2:
184 release_mem_region(cxt->phys_addr, cxt->size);
185 fail3:
186 return err;
187 }
188
ramoops_remove(struct platform_device * pdev)189 static int __exit ramoops_remove(struct platform_device *pdev)
190 {
191 struct ramoops_context *cxt = &oops_cxt;
192
193 if (kmsg_dump_unregister(&cxt->dump) < 0)
194 pr_warn("could not unregister kmsg_dumper\n");
195
196 iounmap(cxt->virt_addr);
197 release_mem_region(cxt->phys_addr, cxt->size);
198 return 0;
199 }
200
201 static struct platform_driver ramoops_driver = {
202 .remove = __exit_p(ramoops_remove),
203 .driver = {
204 .name = "ramoops",
205 .owner = THIS_MODULE,
206 },
207 };
208
ramoops_init(void)209 static int __init ramoops_init(void)
210 {
211 int ret;
212 ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
213 if (ret == -ENODEV) {
214 /*
215 * If we didn't find a platform device, we use module parameters
216 * building platform data on the fly.
217 */
218 pr_info("platform device not found, using module parameters\n");
219 dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
220 GFP_KERNEL);
221 if (!dummy_data)
222 return -ENOMEM;
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,
228 NULL, 0, dummy_data,
229 sizeof(struct ramoops_platform_data));
230
231 if (IS_ERR(dummy))
232 ret = PTR_ERR(dummy);
233 else
234 ret = 0;
235 }
236
237 return ret;
238 }
239
ramoops_exit(void)240 static void __exit ramoops_exit(void)
241 {
242 platform_driver_unregister(&ramoops_driver);
243 kfree(dummy_data);
244 }
245
246 module_init(ramoops_init);
247 module_exit(ramoops_exit);
248
249 MODULE_LICENSE("GPL");
250 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
251 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
252