1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
|
/*
* c 2001 PPC 64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* scan-log-data driver for PPC64 Todd Inglett <tinglett@vnet.ibm.com>
*
* When ppc64 hardware fails the service processor dumps internal state
* of the system. After a reboot the operating system can access a dump
* of this data using this driver. A dump exists if the device-tree
* /chosen/ibm,scan-log-data property exists.
*
* This driver exports /proc/ppc64/scan-log-dump which can be read.
* The driver supports only sequential reads.
*
* The driver looks at a write to the driver for the single word "reset".
* If given, the driver will reset the scanlog so the platform can free it.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/rtas.h>
#include <asm/prom.h>
#define MODULE_VERS "1.0"
#define MODULE_NAME "scanlog"
/* Status returns from ibm,scan-log-dump */
#define SCANLOG_COMPLETE 0
#define SCANLOG_HWERROR -1
#define SCANLOG_CONTINUE 1
#define DEBUG(A...) do { if (scanlog_debug) printk(KERN_ERR "scanlog: " A); } while (0)
static int scanlog_debug;
static unsigned int ibm_scan_log_dump; /* RTAS token */
static struct proc_dir_entry *proc_ppc64_scan_log_dump; /* The proc file */
static ssize_t scanlog_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_dentry->d_inode;
struct proc_dir_entry *dp;
unsigned int *data;
int status;
unsigned long len, off;
unsigned int wait_time;
dp = PDE(inode);
data = (unsigned int *)dp->data;
if (!data) {
printk(KERN_ERR "scanlog: read failed no data\n");
return -EIO;
}
if (count > RTAS_DATA_BUF_SIZE)
count = RTAS_DATA_BUF_SIZE;
if (count < 1024) {
/* This is the min supported by this RTAS call. Rather
* than do all the buffering we insist the user code handle
* larger reads. As long as cp works... :)
*/
printk(KERN_ERR "scanlog: cannot perform a small read (%ld)\n", count);
return -EINVAL;
}
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
for (;;) {
wait_time = 500; /* default wait if no data */
spin_lock(&rtas_data_buf_lock);
memcpy(rtas_data_buf, data, RTAS_DATA_BUF_SIZE);
status = rtas_call(ibm_scan_log_dump, 2, 1, NULL,
(u32) __pa(rtas_data_buf), (u32) count);
memcpy(data, rtas_data_buf, RTAS_DATA_BUF_SIZE);
spin_unlock(&rtas_data_buf_lock);
DEBUG("status=%d, data[0]=%x, data[1]=%x, data[2]=%x\n",
status, data[0], data[1], data[2]);
switch (status) {
case SCANLOG_COMPLETE:
DEBUG("hit eof\n");
return 0;
case SCANLOG_HWERROR:
DEBUG("hardware error reading scan log data\n");
return -EIO;
case SCANLOG_CONTINUE:
/* We may or may not have data yet */
len = data[1];
off = data[2];
if (len > 0) {
if (copy_to_user(buf, ((char *)data)+off, len))
return -EFAULT;
return len;
}
/* Break to sleep default time */
break;
default:
if (status > 9900 && status <= 9905) {
wait_time = rtas_extended_busy_delay_time(status);
} else {
printk(KERN_ERR "scanlog: unknown error from rtas: %d\n", status);
return -EIO;
}
}
/* Apparently no data yet. Wait and try again. */
msleep_interruptible(wait_time);
}
/*NOTREACHED*/
}
static ssize_t scanlog_write(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
char stkbuf[20];
int status;
if (count > 19) count = 19;
if (copy_from_user (stkbuf, buf, count)) {
return -EFAULT;
}
stkbuf[count] = 0;
if (buf) {
if (strncmp(stkbuf, "reset", 5) == 0) {
DEBUG("reset scanlog\n");
status = rtas_call(ibm_scan_log_dump, 2, 1, NULL, 0, 0);
DEBUG("rtas returns %d\n", status);
} else if (strncmp(stkbuf, "debugon", 7) == 0) {
printk(KERN_ERR "scanlog: debug on\n");
scanlog_debug = 1;
} else if (strncmp(stkbuf, "debugoff", 8) == 0) {
printk(KERN_ERR "scanlog: debug off\n");
scanlog_debug = 0;
}
}
return count;
}
static int scanlog_open(struct inode * inode, struct file * file)
{
struct proc_dir_entry *dp = PDE(inode);
unsigned int *data = (unsigned int *)dp->data;
if (!data) {
printk(KERN_ERR "scanlog: open failed no data\n");
return -EIO;
}
if (data[0] != 0) {
/* This imperfect test stops a second copy of the
* data (or a reset while data is being copied)
*/
return -EBUSY;
}
data[0] = 0; /* re-init so we restart the scan */
return 0;
}
static int scanlog_release(struct inode * inode, struct file * file)
{
struct proc_dir_entry *dp = PDE(inode);
unsigned int *data = (unsigned int *)dp->data;
if (!data) {
printk(KERN_ERR "scanlog: release failed no data\n");
return -EIO;
}
data[0] = 0;
return 0;
}
struct file_operations scanlog_fops = {
.owner = THIS_MODULE,
.read = scanlog_read,
.write = scanlog_write,
.open = scanlog_open,
.release = scanlog_release,
};
int __init scanlog_init(void)
{
struct proc_dir_entry *ent;
ibm_scan_log_dump = rtas_token("ibm,scan-log-dump");
if (ibm_scan_log_dump == RTAS_UNKNOWN_SERVICE) {
printk(KERN_ERR "scan-log-dump not implemented on this system\n");
return -EIO;
}
ent = create_proc_entry("ppc64/rtas/scan-log-dump", S_IRUSR, NULL);
if (ent) {
ent->proc_fops = &scanlog_fops;
/* Ideally we could allocate a buffer < 4G */
ent->data = kmalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
if (!ent->data) {
printk(KERN_ERR "Failed to allocate a buffer\n");
remove_proc_entry("scan-log-dump", ent->parent);
return -ENOMEM;
}
((unsigned int *)ent->data)[0] = 0;
} else {
printk(KERN_ERR "Failed to create ppc64/scan-log-dump proc entry\n");
return -EIO;
}
proc_ppc64_scan_log_dump = ent;
return 0;
}
void __exit scanlog_cleanup(void)
{
if (proc_ppc64_scan_log_dump) {
kfree(proc_ppc64_scan_log_dump->data);
remove_proc_entry("scan-log-dump", proc_ppc64_scan_log_dump->parent);
}
}
module_init(scanlog_init);
module_exit(scanlog_cleanup);
MODULE_LICENSE("GPL");
|
