drivers/s390/block/dasd_cmb.c

   1 /*
   2  * linux/drivers/s390/block/dasd_cmb.c ($Revision: 1.6 $)
   3  *
   4  * Linux on zSeries Channel Measurement Facility support
   5  *  (dasd device driver interface)
   6  *
   7  * Copyright 2000,2003 IBM Corporation
   8  *
   9  * Author: Arnd Bergmann <arndb@de.ibm.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2, or (at your option)
  14  * any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25 #include <linux/init.h>
  26 #include <linux/ioctl32.h>
  27 #include <linux/module.h>
  28 #include <asm/ccwdev.h>
  29 #include <asm/cmb.h>
  30
  31 #include "dasd_int.h"
  32
  33 static int
  34 dasd_ioctl_cmf_enable(struct block_device *bdev, int no, long args)
  35 {
  36         struct dasd_device *device;
  37
  38         device = bdev->bd_disk->private_data;
  39         if (!device)
  40                 return -EINVAL;
  41
  42         return enable_cmf(device->cdev);
  43 }
  44
  45 static int
  46 dasd_ioctl_cmf_disable(struct block_device *bdev, int no, long args)
  47 {
  48         struct dasd_device *device;
  49
  50         device = bdev->bd_disk->private_data;
  51         if (!device)
  52                 return -EINVAL;
  53
  54         return disable_cmf(device->cdev);
  55 }
  56
  57 static int
  58 dasd_ioctl_readall_cmb(struct block_device *bdev, int no, long args)
  59 {
  60         struct dasd_device *device;
  61         struct cmbdata __user *udata;
  62         struct cmbdata data;
  63         size_t size;
  64         int ret;
  65
  66         device = bdev->bd_disk->private_data;
  67         if (!device)
  68                 return -EINVAL;
  69         udata = (void __user *) args;
  70         size = _IOC_SIZE(no);
  71
  72         if (!access_ok(VERIFY_WRITE, udata, size))
  73                 return -EFAULT;
  74         ret = cmf_readall(device->cdev, &data);
  75         if (ret)
  76                 return ret;
  77         if (copy_to_user(udata, &data, min(size, sizeof(*udata))))
  78                 return -EFAULT;
  79         return 0;
  80 }
  81
  82 /* module initialization below here. dasd already provides a mechanism
  83  * to dynamically register ioctl functions, so we simply use this. */
  84 static inline int
  85 ioctl_reg(unsigned int no, dasd_ioctl_fn_t handler)
  86 {
  87         int ret;
  88         ret = dasd_ioctl_no_register(THIS_MODULE, no, handler);
  89 #ifdef CONFIG_COMPAT
  90         if (ret)
  91                 return ret;
  92
  93         ret = register_ioctl32_conversion(no, NULL);
  94         if (ret)
  95                 dasd_ioctl_no_unregister(THIS_MODULE, no, handler);
  96 #endif
  97         return ret;
  98 }
  99
 100 static inline void
 101 ioctl_unreg(unsigned int no, dasd_ioctl_fn_t handler)
 102 {
 103         dasd_ioctl_no_unregister(THIS_MODULE, no, handler);
 104 #ifdef CONFIG_COMPAT
 105         unregister_ioctl32_conversion(no);
 106 #endif
 107
 108 }
 109
 110 static void
 111 dasd_cmf_exit(void)
 112 {
 113         ioctl_unreg(BIODASDCMFENABLE,  dasd_ioctl_cmf_enable);
 114         ioctl_unreg(BIODASDCMFDISABLE, dasd_ioctl_cmf_disable);
 115         ioctl_unreg(BIODASDREADALLCMB, dasd_ioctl_readall_cmb);
 116 }
 117
 118 static int __init
 119 dasd_cmf_init(void)
 120 {
 121         int ret;
 122         ret = ioctl_reg (BIODASDCMFENABLE, dasd_ioctl_cmf_enable);
 123         if (ret)
 124                 goto err;
 125         ret = ioctl_reg (BIODASDCMFDISABLE, dasd_ioctl_cmf_disable);
 126         if (ret)
 127                 goto err;
 128         ret = ioctl_reg (BIODASDREADALLCMB, dasd_ioctl_readall_cmb);
 129         if (ret)
 130                 goto err;
 131
 132         return 0;
 133 err:
 134         dasd_cmf_exit();
 135
 136         return ret;
 137 }
 138
 139 module_init(dasd_cmf_init);
 140 module_exit(dasd_cmf_exit);
 141
 142 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 143 MODULE_LICENSE("GPL");
 144 MODULE_DESCRIPTION("channel measurement facility interface for dasd\n"
 145                    "Copyright 2003 IBM Corporation\n");