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>
30 #include <linux/ioport.h>
31 #include <linux/platform_device.h>
32 #include <linux/slab.h>
33 #include <linux/ramoops.h>
35 #define RAMOOPS_KERNMSG_HDR "===="
36 #define MIN_MEM_SIZE 4096UL
38 static ulong record_size = MIN_MEM_SIZE;
39 module_param(record_size, ulong, 0400);
40 MODULE_PARM_DESC(record_size,
41 "size of each dump done on oops/panic");
43 static ulong mem_address;
44 module_param(mem_address, ulong, 0400);
45 MODULE_PARM_DESC(mem_address,
46 "start of reserved RAM used to store oops/panic logs");
48 static ulong mem_size;
49 module_param(mem_size, ulong, 0400);
50 MODULE_PARM_DESC(mem_size,
51 "size of reserved RAM used to store oops/panic logs");
53 static int dump_oops = 1;
54 module_param(dump_oops, int, 0600);
55 MODULE_PARM_DESC(dump_oops,
56 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
58 static struct ramoops_context {
59 struct kmsg_dumper dump;
61 phys_addr_t phys_addr;
63 unsigned long record_size;
69 static struct platform_device *dummy;
70 static struct ramoops_platform_data *dummy_data;
72 static void ramoops_do_dump(struct kmsg_dumper *dumper,
73 enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
74 const char *s2, unsigned long l2)
76 struct ramoops_context *cxt = container_of(dumper,
77 struct ramoops_context, dump);
78 unsigned long s1_start, s2_start;
79 unsigned long l1_cpy, l2_cpy;
82 struct timeval timestamp;
84 if (reason != KMSG_DUMP_OOPS &&
85 reason != KMSG_DUMP_PANIC &&
86 reason != KMSG_DUMP_KEXEC)
89 /* Only dump oopses if dump_oops is set */
90 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
93 buf = cxt->virt_addr + (cxt->count * cxt->record_size);
96 memset(buf, '\0', cxt->record_size);
97 res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
99 do_gettimeofday(×tamp);
100 res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
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);
107 s2_start = l2 - l2_cpy;
108 s1_start = l1 - l1_cpy;
110 memcpy(buf, s1 + s1_start, l1_cpy);
111 memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
113 cxt->count = (cxt->count + 1) % cxt->max_count;
116 static int __init ramoops_probe(struct platform_device *pdev)
118 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
119 struct ramoops_context *cxt = &oops_cxt;
122 if (!pdata->mem_size || !pdata->record_size) {
123 pr_err("The memory size and the record size must be "
128 rounddown_pow_of_two(pdata->mem_size);
129 rounddown_pow_of_two(pdata->record_size);
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);
138 if (pdata->mem_size < pdata->record_size) {
139 pr_err("The memory size must be larger than the "
144 cxt->max_count = pdata->mem_size / pdata->record_size;
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;
151 if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
152 pr_err("request mem region failed\n");
157 cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
158 if (!cxt->virt_addr) {
159 pr_err("ioremap failed\n");
163 cxt->dump.dump = ramoops_do_dump;
164 err = kmsg_dump_register(&cxt->dump);
166 pr_err("registering kmsg dumper failed\n");
173 iounmap(cxt->virt_addr);
175 release_mem_region(cxt->phys_addr, cxt->size);
180 static int __exit ramoops_remove(struct platform_device *pdev)
182 struct ramoops_context *cxt = &oops_cxt;
184 if (kmsg_dump_unregister(&cxt->dump) < 0)
185 pr_warn("could not unregister kmsg_dumper\n");
187 iounmap(cxt->virt_addr);
188 release_mem_region(cxt->phys_addr, cxt->size);
192 static struct platform_driver ramoops_driver = {
193 .remove = __exit_p(ramoops_remove),
196 .owner = THIS_MODULE,
200 static int __init ramoops_init(void)
203 ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
204 if (ret == -ENODEV) {
206 * If we didn't find a platform device, we use module parameters
207 * building platform data on the fly.
209 pr_info("platform device not found, using module parameters\n");
210 dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
214 dummy_data->mem_size = mem_size;
215 dummy_data->mem_address = mem_address;
216 dummy_data->record_size = record_size;
217 dummy_data->dump_oops = dump_oops;
218 dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
220 sizeof(struct ramoops_platform_data));
223 ret = PTR_ERR(dummy);
231 static void __exit ramoops_exit(void)
233 platform_driver_unregister(&ramoops_driver);
237 module_init(ramoops_init);
238 module_exit(ramoops_exit);
240 MODULE_LICENSE("GPL");
241 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
242 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");