ramoops: move dump_oops into platform data
[linux-2.6.git] / drivers / char / ramoops.c
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(&timestamp);
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");