aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/s390/char/sclp_async.c
blob: 7ad30e72f868de1e45ef7e4bdd81cfa8a4701ca4 (plain)
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
/*
 * Enable Asynchronous Notification via SCLP.
 *
 * Copyright IBM Corp. 2009
 * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/sysctl.h>
#include <linux/utsname.h>
#include "sclp.h"

static int callhome_enabled;
static struct sclp_req *request;
static struct sclp_async_sccb *sccb;
static int sclp_async_send_wait(char *message);
static struct ctl_table_header *callhome_sysctl_header;
static DEFINE_SPINLOCK(sclp_async_lock);
#define SCLP_NORMAL_WRITE	0x00

struct async_evbuf {
	struct evbuf_header header;
	u64 reserved;
	u8 rflags;
	u8 empty;
	u8 rtype;
	u8 otype;
	char comp_id[12];
	char data[3000]; /* there is still some space left */
} __attribute__((packed));

struct sclp_async_sccb {
	struct sccb_header header;
	struct async_evbuf evbuf;
} __attribute__((packed));

static struct sclp_register sclp_async_register = {
	.send_mask = EVTYP_ASYNC_MASK,
};

static int call_home_on_panic(struct notifier_block *self,
			      unsigned long event, void *data)
{
	strncat(data, init_utsname()->nodename,
		sizeof(init_utsname()->nodename));
	sclp_async_send_wait(data);
	return NOTIFY_DONE;
}

static struct notifier_block call_home_panic_nb = {
	.notifier_call = call_home_on_panic,
	.priority = INT_MAX,
};

static int proc_handler_callhome(struct ctl_table *ctl, int write,
				 void __user *buffer, size_t *count,
				 loff_t *ppos)
{
	unsigned long val;
	int len, rc;
	char buf[3];

	if (!*count || (*ppos && !write)) {
		*count = 0;
		return 0;
	}
	if (!write) {
		len = snprintf(buf, sizeof(buf), "%d\n", callhome_enabled);
		rc = copy_to_user(buffer, buf, sizeof(buf));
		if (rc != 0)
			return -EFAULT;
	} else {
		len = *count;
		rc = copy_from_user(buf, buffer, sizeof(buf));
		if (rc != 0)
			return -EFAULT;
		buf[sizeof(buf) - 1] = '\0';
		if (strict_strtoul(buf, 0, &val) != 0)
			return -EINVAL;
		if (val != 0 && val != 1)
			return -EINVAL;
		callhome_enabled = val;
	}
	*count = len;
	*ppos += len;
	return 0;
}

static struct ctl_table callhome_table[] = {
	{
		.procname	= "callhome",
		.mode		= 0644,
		.proc_handler	= proc_handler_callhome,
	},
	{}
};

static struct ctl_table kern_dir_table[] = {
	{
		.procname	= "kernel",
		.maxlen		= 0,
		.mode		= 0555,
		.child		= callhome_table,
	},
	{}
};

/*
 * Function used to transfer asynchronous notification
 * records which waits for send completion
 */
static int sclp_async_send_wait(char *message)
{
	struct async_evbuf *evb;
	int rc;
	unsigned long flags;

	if (!callhome_enabled)
		return 0;
	sccb->evbuf.header.type = EVTYP_ASYNC;
	sccb->evbuf.rtype = 0xA5;
	sccb->evbuf.otype = 0x00;
	evb = &sccb->evbuf;
	request->command = SCLP_CMDW_WRITE_EVENT_DATA;
	request->sccb = sccb;
	request->status = SCLP_REQ_FILLED;
	strncpy(sccb->evbuf.data, message, sizeof(sccb->evbuf.data));
	/*
	 * Retain Queue
	 * e.g. 5639CC140 500 Red Hat RHEL5 Linux for zSeries (RHEL AS)
	 */
	strncpy(sccb->evbuf.comp_id, "000000000", sizeof(sccb->evbuf.comp_id));
	sccb->evbuf.header.length = sizeof(sccb->evbuf);
	sccb->header.length = sizeof(sccb->evbuf) + sizeof(sccb->header);
	sccb->header.function_code = SCLP_NORMAL_WRITE;
	rc = sclp_add_request(request);
	if (rc)
		return rc;
	spin_lock_irqsave(&sclp_async_lock, flags);
	while (request->status != SCLP_REQ_DONE &&
		request->status != SCLP_REQ_FAILED) {
		 sclp_sync_wait();
	}
	spin_unlock_irqrestore(&sclp_async_lock, flags);
	if (request->status != SCLP_REQ_DONE)
		return -EIO;
	rc = ((struct sclp_async_sccb *)
	       request->sccb)->header.response_code;
	if (rc != 0x0020)
		return -EIO;
	if (evb->header.flags != 0x80)
		return -EIO;
	return rc;
}

static int __init sclp_async_init(void)
{
	int rc;

	rc = sclp_register(&sclp_async_register);
	if (rc)
		return rc;
	rc = -EOPNOTSUPP;
	if (!(sclp_async_register.sclp_receive_mask & EVTYP_ASYNC_MASK))
		goto out_sclp;
	rc = -ENOMEM;
	callhome_sysctl_header = register_sysctl_table(kern_dir_table);
	if (!callhome_sysctl_header)
		goto out_sclp;
	request = kzalloc(sizeof(struct sclp_req), GFP_KERNEL);
	sccb = (struct sclp_async_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!request || !sccb)
		goto out_mem;
	rc = atomic_notifier_chain_register(&panic_notifier_list,
					    &call_home_panic_nb);
	if (!rc)
		goto out;
out_mem:
	kfree(request);
	free_page((unsigned long) sccb);
	unregister_sysctl_table(callhome_sysctl_header);
out_sclp:
	sclp_unregister(&sclp_async_register);
out:
	return rc;
}
module_init(sclp_async_init);

static void __exit sclp_async_exit(void)
{
	atomic_notifier_chain_unregister(&panic_notifier_list,
					 &call_home_panic_nb);
	unregister_sysctl_table(callhome_sysctl_header);
	sclp_unregister(&sclp_async_register);
	free_page((unsigned long) sccb);
	kfree(request);
}
module_exit(sclp_async_exit);

MODULE_AUTHOR("Copyright IBM Corp. 2009");
MODULE_AUTHOR("Hans-Joachim Picht <hans@linux.vnet.ibm.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SCLP Asynchronous Notification Records");