drivers/s390/net/smsgiucv.c

   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 *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 spinlock_t smsg_list_lock = SPIN_LOCK_UNLOCKED;
  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 short len;
  59         int rc;
  60
  61         len = eib->ln1msg2.ipbfln1f;
  62         msg = kmalloc(len + 1, GFP_ATOMIC|GFP_DMA);
  63         if (!msg) {
  64                 iucv_reject(eib->ippathid, eib->ipmsgid, eib->iptrgcls);
  65                 return;
  66         }
  67         rc = iucv_receive(eib->ippathid, eib->ipmsgid, eib->iptrgcls,
  68                           msg, len, 0, 0, 0);
  69         if (rc == 0) {
  70                 msg[len] = 0;
  71                 EBCASC(msg, len);
  72                 spin_lock(&smsg_list_lock);
  73                 list_for_each_entry(cb, &smsg_list, list)
  74                         if (strncmp(msg + 8, cb->prefix, cb->len) == 0) {
  75                                 cb->callback(msg + 8);
  76                                 break;
  77                         }
  78                 spin_unlock(&smsg_list_lock);
  79         }
  80         kfree(msg);
  81 }
  82
  83 static iucv_interrupt_ops_t smsg_ops = {
  84         .ConnectionComplete = smsg_connection_complete,
  85         .MessagePending     = smsg_message_pending,
  86 };
  87
  88 static struct device_driver smsg_driver = {
  89         .name = "SMSGIUCV",
  90         .bus  = &iucv_bus,
  91 };
  92
  93 int
  94 smsg_register_callback(char *prefix, void (*callback)(char *str))
  95 {
  96         struct smsg_callback *cb;
  97
  98         cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
  99         if (!cb)
 100                 return -ENOMEM;
 101         cb->prefix = prefix;
 102         cb->len = strlen(prefix);
 103         cb->callback = callback;
 104         spin_lock(&smsg_list_lock);
 105         list_add_tail(&cb->list, &smsg_list);
 106         spin_unlock(&smsg_list_lock);
 107         return 0;
 108 }
 109
 110 void
 111 smsg_unregister_callback(char *prefix, void (*callback)(char *str))
 112 {
 113         struct smsg_callback *cb, *tmp;
 114
 115         spin_lock(&smsg_list_lock);
 116         cb = 0;
 117         list_for_each_entry(tmp, &smsg_list, list)
 118                 if (tmp->callback == callback &&
 119                     strcmp(tmp->prefix, prefix) == 0) {
 120                         cb = tmp;
 121                         list_del(&cb->list);
 122                         break;
 123                 }
 124         spin_unlock(&smsg_list_lock);
 125         kfree(cb);
 126 }
 127
 128 static void __exit
 129 smsg_exit(void)
 130 {
 131         if (smsg_handle > 0) {
 132                 cpcmd("SET SMSG OFF", 0, 0);
 133                 iucv_sever(smsg_pathid, 0);
 134                 iucv_unregister_program(smsg_handle);
 135                 driver_unregister(&smsg_driver);
 136         }
 137         return;
 138 }
 139
 140 static int __init
 141 smsg_init(void)
 142 {
 143         static unsigned char pgmmask[24] = {
 144                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 145                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 146                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 147         };
 148         int rc;
 149
 150         rc = driver_register(&smsg_driver);
 151         if (rc != 0) {
 152                 printk(KERN_ERR "SMSGIUCV: failed to register driver.\n");
 153                 return rc;
 154         }
 155         smsg_handle = iucv_register_program("SMSGIUCV        ", "*MSG    ",
 156                                             pgmmask, &smsg_ops, 0);
 157         if (!smsg_handle) {
 158                 printk(KERN_ERR "SMSGIUCV: failed to register to iucv");
 159                 driver_unregister(&smsg_driver);
 160                 return -EIO;    /* better errno ? */
 161         }
 162         rc = iucv_connect (&smsg_pathid, 1, 0, "*MSG    ", 0, 0, 0, 0,
 163                            smsg_handle, 0);
 164         if (rc) {
 165                 printk(KERN_ERR "SMSGIUCV: failed to connect to *MSG");
 166                 iucv_unregister_program(smsg_handle);
 167                 driver_unregister(&smsg_driver);
 168                 smsg_handle = 0;
 169                 return -EIO;
 170         }
 171         cpcmd("SET SMSG IUCV", 0, 0);
 172         return 0;
 173 }
 174
 175 module_init(smsg_init);
 176 module_exit(smsg_exit);
 177 MODULE_LICENSE("GPL");
 178
 179 EXPORT_SYMBOL(smsg_register_callback);
 180 EXPORT_SYMBOL(smsg_unregister_callback);