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 *, u8 *);
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, u8 *ipuser)
61{
62	if (strncmp(ipvmid, "*MSG    ", 8) != 0)
63		return -EINVAL;
64	/* Path pending from *MSG. */
65	return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);
66}
67
68static void smsg_message_pending(struct iucv_path *path,
69				 struct iucv_message *msg)
70{
71	struct smsg_callback *cb;
72	unsigned char *buffer;
73	unsigned char sender[9];
74	int rc, i;
75
76	buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);
77	if (!buffer) {
78		iucv_message_reject(path, msg);
79		return;
80	}
81	rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);
82	if (rc == 0) {
83		buffer[msg->length] = 0;
84		EBCASC(buffer, msg->length);
85		memcpy(sender, buffer, 8);
86		sender[8] = 0;
87		/* Remove trailing whitespace from the sender name. */
88		for (i = 7; i >= 0; i--) {
89			if (sender[i] != ' ' && sender[i] != '\t')
90				break;
91			sender[i] = 0;
92		}
93		spin_lock(&smsg_list_lock);
94		list_for_each_entry(cb, &smsg_list, list)
95			if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
96				cb->callback(sender, buffer + 8);
97				break;
98			}
99		spin_unlock(&smsg_list_lock);
100	}
101	kfree(buffer);
102}
103
104int smsg_register_callback(const char *prefix,
105			   void (*callback)(const char *from, char *str))
106{
107	struct smsg_callback *cb;
108
109	cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
110	if (!cb)
111		return -ENOMEM;
112	cb->prefix = prefix;
113	cb->len = strlen(prefix);
114	cb->callback = callback;
115	spin_lock_bh(&smsg_list_lock);
116	list_add_tail(&cb->list, &smsg_list);
117	spin_unlock_bh(&smsg_list_lock);
118	return 0;
119}
120
121void smsg_unregister_callback(const char *prefix,
122			      void (*callback)(const char *from,
123					       char *str))
124{
125	struct smsg_callback *cb, *tmp;
126
127	spin_lock_bh(&smsg_list_lock);
128	cb = NULL;
129	list_for_each_entry(tmp, &smsg_list, list)
130		if (tmp->callback == callback &&
131		    strcmp(tmp->prefix, prefix) == 0) {
132			cb = tmp;
133			list_del(&cb->list);
134			break;
135		}
136	spin_unlock_bh(&smsg_list_lock);
137	kfree(cb);
138}
139
140static int smsg_pm_freeze(struct device *dev)
141{
142#ifdef CONFIG_PM_DEBUG
143	printk(KERN_WARNING "smsg_pm_freeze\n");
144#endif
145	if (smsg_path && iucv_path_connected) {
146		iucv_path_sever(smsg_path, NULL);
147		iucv_path_connected = 0;
148	}
149	return 0;
150}
151
152static int smsg_pm_restore_thaw(struct device *dev)
153{
154	int rc;
155
156#ifdef CONFIG_PM_DEBUG
157	printk(KERN_WARNING "smsg_pm_restore_thaw\n");
158#endif
159	if (smsg_path && !iucv_path_connected) {
160		memset(smsg_path, 0, sizeof(*smsg_path));
161		smsg_path->msglim = 255;
162		smsg_path->flags = 0;
163		rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
164				       NULL, NULL, NULL);
165#ifdef CONFIG_PM_DEBUG
166		if (rc)
167			printk(KERN_ERR
168			       "iucv_path_connect returned with rc %i\n", rc);
169#endif
170		if (!rc)
171			iucv_path_connected = 1;
172		cpcmd("SET SMSG IUCV", NULL, 0, NULL);
173	}
174	return 0;
175}
176
177static const struct dev_pm_ops smsg_pm_ops = {
178	.freeze = smsg_pm_freeze,
179	.thaw = smsg_pm_restore_thaw,
180	.restore = smsg_pm_restore_thaw,
181};
182
183static struct device_driver smsg_driver = {
184	.owner = THIS_MODULE,
185	.name = SMSGIUCV_DRV_NAME,
186	.bus  = &iucv_bus,
187	.pm = &smsg_pm_ops,
188};
189
190static void __exit smsg_exit(void)
191{
192	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
193	device_unregister(smsg_dev);
194	iucv_unregister(&smsg_handler, 1);
195	driver_unregister(&smsg_driver);
196}
197
198static int __init smsg_init(void)
199{
200	int rc;
201
202	if (!MACHINE_IS_VM) {
203		rc = -EPROTONOSUPPORT;
204		goto out;
205	}
206	rc = driver_register(&smsg_driver);
207	if (rc != 0)
208		goto out;
209	rc = iucv_register(&smsg_handler, 1);
210	if (rc)
211		goto out_driver;
212	smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
213	if (!smsg_path) {
214		rc = -ENOMEM;
215		goto out_register;
216	}
217	rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
218			       NULL, NULL, NULL);
219	if (rc)
220		goto out_free_path;
221	else
222		iucv_path_connected = 1;
223	smsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
224	if (!smsg_dev) {
225		rc = -ENOMEM;
226		goto out_free_path;
227	}
228	dev_set_name(smsg_dev, "smsg_iucv");
229	smsg_dev->bus = &iucv_bus;
230	smsg_dev->parent = iucv_root;
231	smsg_dev->release = (void (*)(struct device *))kfree;
232	smsg_dev->driver = &smsg_driver;
233	rc = device_register(smsg_dev);
234	if (rc)
235		goto out_put;
236
237	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
238	return 0;
239
240out_put:
241	put_device(smsg_dev);
242out_free_path:
243	iucv_path_free(smsg_path);
244	smsg_path = NULL;
245out_register:
246	iucv_unregister(&smsg_handler, 1);
247out_driver:
248	driver_unregister(&smsg_driver);
249out:
250	return rc;
251}
252
253module_init(smsg_init);
254module_exit(smsg_exit);
255MODULE_LICENSE("GPL");
256
257EXPORT_SYMBOL(smsg_register_callback);
258EXPORT_SYMBOL(smsg_unregister_callback);
259