xref: /openbmc/linux/drivers/s390/net/smsgiucv.c (revision 87c2ce3b)
1 /*
2  * IUCV special message driver
3  *
4  * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
5  * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2, or (at your option)
10  * any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/errno.h>
25 #include <linux/device.h>
26 #include <asm/cpcmd.h>
27 #include <asm/ebcdic.h>
28 
29 #include "iucv.h"
30 
31 struct smsg_callback {
32 	struct list_head list;
33 	char *prefix;
34 	int len;
35 	void (*callback)(char *from, char *str);
36 };
37 
38 MODULE_AUTHOR
39    ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
40 MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
41 
42 static iucv_handle_t smsg_handle;
43 static unsigned short smsg_pathid;
44 static DEFINE_SPINLOCK(smsg_list_lock);
45 static struct list_head smsg_list = LIST_HEAD_INIT(smsg_list);
46 
47 static void
48 smsg_connection_complete(iucv_ConnectionComplete *eib, void *pgm_data)
49 {
50 }
51 
52 
53 static void
54 smsg_message_pending(iucv_MessagePending *eib, void *pgm_data)
55 {
56 	struct smsg_callback *cb;
57 	unsigned char *msg;
58 	unsigned char sender[9];
59 	unsigned short len;
60 	int rc, i;
61 
62 	len = eib->ln1msg2.ipbfln1f;
63 	msg = kmalloc(len + 1, GFP_ATOMIC|GFP_DMA);
64 	if (!msg) {
65 		iucv_reject(eib->ippathid, eib->ipmsgid, eib->iptrgcls);
66 		return;
67 	}
68 	rc = iucv_receive(eib->ippathid, eib->ipmsgid, eib->iptrgcls,
69 			  msg, len, 0, 0, 0);
70 	if (rc == 0) {
71 		msg[len] = 0;
72 		EBCASC(msg, len);
73 		memcpy(sender, msg, 8);
74 		sender[8] = 0;
75 		/* Remove trailing whitespace from the sender name. */
76 		for (i = 7; i >= 0; i--) {
77 			if (sender[i] != ' ' && sender[i] != '\t')
78 				break;
79 			sender[i] = 0;
80 		}
81 		spin_lock(&smsg_list_lock);
82 		list_for_each_entry(cb, &smsg_list, list)
83 			if (strncmp(msg + 8, cb->prefix, cb->len) == 0) {
84 				cb->callback(sender, msg + 8);
85 				break;
86 			}
87 		spin_unlock(&smsg_list_lock);
88 	}
89 	kfree(msg);
90 }
91 
92 static iucv_interrupt_ops_t smsg_ops = {
93 	.ConnectionComplete = smsg_connection_complete,
94 	.MessagePending     = smsg_message_pending,
95 };
96 
97 static struct device_driver smsg_driver = {
98 	.name = "SMSGIUCV",
99 	.bus  = &iucv_bus,
100 };
101 
102 int
103 smsg_register_callback(char *prefix, void (*callback)(char *from, char *str))
104 {
105 	struct smsg_callback *cb;
106 
107 	cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
108 	if (!cb)
109 		return -ENOMEM;
110 	cb->prefix = prefix;
111 	cb->len = strlen(prefix);
112 	cb->callback = callback;
113 	spin_lock(&smsg_list_lock);
114 	list_add_tail(&cb->list, &smsg_list);
115 	spin_unlock(&smsg_list_lock);
116 	return 0;
117 }
118 
119 void
120 smsg_unregister_callback(char *prefix, void (*callback)(char *from, char *str))
121 {
122 	struct smsg_callback *cb, *tmp;
123 
124 	spin_lock(&smsg_list_lock);
125 	cb = 0;
126 	list_for_each_entry(tmp, &smsg_list, list)
127 		if (tmp->callback == callback &&
128 		    strcmp(tmp->prefix, prefix) == 0) {
129 			cb = tmp;
130 			list_del(&cb->list);
131 			break;
132 		}
133 	spin_unlock(&smsg_list_lock);
134 	kfree(cb);
135 }
136 
137 static void __exit
138 smsg_exit(void)
139 {
140 	if (smsg_handle > 0) {
141 		cpcmd("SET SMSG OFF", NULL, 0, NULL);
142 		iucv_sever(smsg_pathid, 0);
143 		iucv_unregister_program(smsg_handle);
144 		driver_unregister(&smsg_driver);
145 	}
146 	return;
147 }
148 
149 static int __init
150 smsg_init(void)
151 {
152 	static unsigned char pgmmask[24] = {
153 		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
154 		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
155 		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
156 	};
157 	int rc;
158 
159 	rc = driver_register(&smsg_driver);
160 	if (rc != 0) {
161 		printk(KERN_ERR "SMSGIUCV: failed to register driver.\n");
162 		return rc;
163 	}
164 	smsg_handle = iucv_register_program("SMSGIUCV        ", "*MSG    ",
165 					    pgmmask, &smsg_ops, 0);
166 	if (!smsg_handle) {
167 		printk(KERN_ERR "SMSGIUCV: failed to register to iucv");
168 		driver_unregister(&smsg_driver);
169 		return -EIO;	/* better errno ? */
170 	}
171 	rc = iucv_connect (&smsg_pathid, 1, 0, "*MSG    ", 0, 0, 0, 0,
172 			   smsg_handle, 0);
173 	if (rc) {
174 		printk(KERN_ERR "SMSGIUCV: failed to connect to *MSG");
175 		iucv_unregister_program(smsg_handle);
176 		driver_unregister(&smsg_driver);
177 		smsg_handle = 0;
178 		return -EIO;
179 	}
180 	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
181 	return 0;
182 }
183 
184 module_init(smsg_init);
185 module_exit(smsg_exit);
186 MODULE_LICENSE("GPL");
187 
188 EXPORT_SYMBOL(smsg_register_callback);
189 EXPORT_SYMBOL(smsg_unregister_callback);
190