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1/*
2 * IUCV special message driver
3 *
4 * Copyright IBM Corp. 2003, 2009
5 *
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/errno.h>
26#include <linux/device.h>
27#include <linux/slab.h>
28#include <net/iucv/iucv.h>
29#include <asm/cpcmd.h>
30#include <asm/ebcdic.h>
31#include "smsgiucv.h"
32
33struct smsg_callback {
34	struct list_head list;
35	const char *prefix;
36	int len;
37	void (*callback)(const char *from, char *str);
38};
39
40MODULE_AUTHOR
41   ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
42MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
43
44static struct iucv_path *smsg_path;
45/* dummy device used as trigger for PM functions */
46static struct device *smsg_dev;
47
48static DEFINE_SPINLOCK(smsg_list_lock);
49static LIST_HEAD(smsg_list);
50static int iucv_path_connected;
51
52static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
53static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
54
55static struct iucv_handler smsg_handler = {
56	.path_pending	 = smsg_path_pending,
57	.message_pending = smsg_message_pending,
58};
59
60static int smsg_path_pending(struct iucv_path *path, u8 ipvmid[8],
61			     u8 ipuser[16])
62{
63	if (strncmp(ipvmid, "*MSG    ", 8) != 0)
64		return -EINVAL;
65	/* Path pending from *MSG. */
66	return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);
67}
68
69static void smsg_message_pending(struct iucv_path *path,
70				 struct iucv_message *msg)
71{
72	struct smsg_callback *cb;
73	unsigned char *buffer;
74	unsigned char sender[9];
75	int rc, i;
76
77	buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);
78	if (!buffer) {
79		iucv_message_reject(path, msg);
80		return;
81	}
82	rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);
83	if (rc == 0) {
84		buffer[msg->length] = 0;
85		EBCASC(buffer, msg->length);
86		memcpy(sender, buffer, 8);
87		sender[8] = 0;
88		/* Remove trailing whitespace from the sender name. */
89		for (i = 7; i >= 0; i--) {
90			if (sender[i] != ' ' && sender[i] != '\t')
91				break;
92			sender[i] = 0;
93		}
94		spin_lock(&smsg_list_lock);
95		list_for_each_entry(cb, &smsg_list, list)
96			if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
97				cb->callback(sender, buffer + 8);
98				break;
99			}
100		spin_unlock(&smsg_list_lock);
101	}
102	kfree(buffer);
103}
104
105int smsg_register_callback(const char *prefix,
106			   void (*callback)(const char *from, char *str))
107{
108	struct smsg_callback *cb;
109
110	cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
111	if (!cb)
112		return -ENOMEM;
113	cb->prefix = prefix;
114	cb->len = strlen(prefix);
115	cb->callback = callback;
116	spin_lock_bh(&smsg_list_lock);
117	list_add_tail(&cb->list, &smsg_list);
118	spin_unlock_bh(&smsg_list_lock);
119	return 0;
120}
121
122void smsg_unregister_callback(const char *prefix,
123			      void (*callback)(const char *from,
124					       char *str))
125{
126	struct smsg_callback *cb, *tmp;
127
128	spin_lock_bh(&smsg_list_lock);
129	cb = NULL;
130	list_for_each_entry(tmp, &smsg_list, list)
131		if (tmp->callback == callback &&
132		    strcmp(tmp->prefix, prefix) == 0) {
133			cb = tmp;
134			list_del(&cb->list);
135			break;
136		}
137	spin_unlock_bh(&smsg_list_lock);
138	kfree(cb);
139}
140
141static int smsg_pm_freeze(struct device *dev)
142{
143#ifdef CONFIG_PM_DEBUG
144	printk(KERN_WARNING "smsg_pm_freeze\n");
145#endif
146	if (smsg_path && iucv_path_connected) {
147		iucv_path_sever(smsg_path, NULL);
148		iucv_path_connected = 0;
149	}
150	return 0;
151}
152
153static int smsg_pm_restore_thaw(struct device *dev)
154{
155	int rc;
156
157#ifdef CONFIG_PM_DEBUG
158	printk(KERN_WARNING "smsg_pm_restore_thaw\n");
159#endif
160	if (smsg_path && !iucv_path_connected) {
161		memset(smsg_path, 0, sizeof(*smsg_path));
162		smsg_path->msglim = 255;
163		smsg_path->flags = 0;
164		rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
165				       NULL, NULL, NULL);
166#ifdef CONFIG_PM_DEBUG
167		if (rc)
168			printk(KERN_ERR
169			       "iucv_path_connect returned with rc %i\n", rc);
170#endif
171		if (!rc)
172			iucv_path_connected = 1;
173		cpcmd("SET SMSG IUCV", NULL, 0, NULL);
174	}
175	return 0;
176}
177
178static const struct dev_pm_ops smsg_pm_ops = {
179	.freeze = smsg_pm_freeze,
180	.thaw = smsg_pm_restore_thaw,
181	.restore = smsg_pm_restore_thaw,
182};
183
184static struct device_driver smsg_driver = {
185	.owner = THIS_MODULE,
186	.name = SMSGIUCV_DRV_NAME,
187	.bus  = &iucv_bus,
188	.pm = &smsg_pm_ops,
189};
190
191static void __exit smsg_exit(void)
192{
193	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
194	device_unregister(smsg_dev);
195	iucv_unregister(&smsg_handler, 1);
196	driver_unregister(&smsg_driver);
197}
198
199static int __init smsg_init(void)
200{
201	int rc;
202
203	if (!MACHINE_IS_VM) {
204		rc = -EPROTONOSUPPORT;
205		goto out;
206	}
207	rc = driver_register(&smsg_driver);
208	if (rc != 0)
209		goto out;
210	rc = iucv_register(&smsg_handler, 1);
211	if (rc)
212		goto out_driver;
213	smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
214	if (!smsg_path) {
215		rc = -ENOMEM;
216		goto out_register;
217	}
218	rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
219			       NULL, NULL, NULL);
220	if (rc)
221		goto out_free_path;
222	else
223		iucv_path_connected = 1;
224	smsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
225	if (!smsg_dev) {
226		rc = -ENOMEM;
227		goto out_free_path;
228	}
229	dev_set_name(smsg_dev, "smsg_iucv");
230	smsg_dev->bus = &iucv_bus;
231	smsg_dev->parent = iucv_root;
232	smsg_dev->release = (void (*)(struct device *))kfree;
233	smsg_dev->driver = &smsg_driver;
234	rc = device_register(smsg_dev);
235	if (rc)
236		goto out_put;
237
238	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
239	return 0;
240
241out_put:
242	put_device(smsg_dev);
243out_free_path:
244	iucv_path_free(smsg_path);
245	smsg_path = NULL;
246out_register:
247	iucv_unregister(&smsg_handler, 1);
248out_driver:
249	driver_unregister(&smsg_driver);
250out:
251	return rc;
252}
253
254module_init(smsg_init);
255module_exit(smsg_exit);
256MODULE_LICENSE("GPL");
257
258EXPORT_SYMBOL(smsg_register_callback);
259EXPORT_SYMBOL(smsg_unregister_callback);
260