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