drivers/s390/block/dasd_cmb.c

   1 /*
   2  * linux/drivers/s390/block/dasd_cmb.c ($Revision: 1.9 $)
   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/module.h>
  27 #include <asm/ccwdev.h>
  28 #include <asm/cmb.h>
  29
  30 #include "dasd_int.h"
  31
  32 static int
  33 dasd_ioctl_cmf_enable(struct block_device *bdev, int no, long args)
  34 {
  35         struct dasd_device *device;
  36
  37         device = bdev->bd_disk->private_data;
  38         if (!device)
  39                 return -EINVAL;
  40
  41         return enable_cmf(device->cdev);
  42 }
  43
  44 static int
  45 dasd_ioctl_cmf_disable(struct block_device *bdev, int no, long args)
  46 {
  47         struct dasd_device *device;
  48
  49         device = bdev->bd_disk->private_data;
  50         if (!device)
  51                 return -EINVAL;
  52
  53         return disable_cmf(device->cdev);
  54 }
  55
  56 static int
  57 dasd_ioctl_readall_cmb(struct block_device *bdev, int no, long args)
  58 {
  59         struct dasd_device *device;
  60         struct cmbdata __user *udata;
  61         struct cmbdata data;
  62         size_t size;
  63         int ret;
  64
  65         device = bdev->bd_disk->private_data;
  66         if (!device)
  67                 return -EINVAL;
  68         udata = (void __user *) args;
  69         size = _IOC_SIZE(no);
  70
  71         if (!access_ok(VERIFY_WRITE, udata, size))
  72                 return -EFAULT;
  73         ret = cmf_readall(device->cdev, &data);
  74         if (ret)
  75                 return ret;
  76         if (copy_to_user(udata, &data, min(size, sizeof(*udata))))
  77                 return -EFAULT;
  78         return 0;
  79 }
  80
  81 /* module initialization below here. dasd already provides a mechanism
  82  * to dynamically register ioctl functions, so we simply use this. */
  83 static inline int
  84 ioctl_reg(unsigned int no, dasd_ioctl_fn_t handler)
  85 {
  86         return dasd_ioctl_no_register(THIS_MODULE, no, handler);
  87 }
  88
  89 static inline void
  90 ioctl_unreg(unsigned int no, dasd_ioctl_fn_t handler)
  91 {
  92         dasd_ioctl_no_unregister(THIS_MODULE, no, handler);
  93 }
  94
  95 static void
  96 dasd_cmf_exit(void)
  97 {
  98         ioctl_unreg(BIODASDCMFENABLE,  dasd_ioctl_cmf_enable);
  99         ioctl_unreg(BIODASDCMFDISABLE, dasd_ioctl_cmf_disable);
 100         ioctl_unreg(BIODASDREADALLCMB, dasd_ioctl_readall_cmb);
 101 }
 102
 103 static int __init
 104 dasd_cmf_init(void)
 105 {
 106         int ret;
 107         ret = ioctl_reg (BIODASDCMFENABLE, dasd_ioctl_cmf_enable);
 108         if (ret)
 109                 goto err;
 110         ret = ioctl_reg (BIODASDCMFDISABLE, dasd_ioctl_cmf_disable);
 111         if (ret)
 112                 goto err;
 113         ret = ioctl_reg (BIODASDREADALLCMB, dasd_ioctl_readall_cmb);
 114         if (ret)
 115                 goto err;
 116
 117         return 0;
 118 err:
 119         dasd_cmf_exit();
 120
 121         return ret;
 122 }
 123
 124 module_init(dasd_cmf_init);
 125 module_exit(dasd_cmf_exit);
 126
 127 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 128 MODULE_LICENSE("GPL");
 129 MODULE_DESCRIPTION("channel measurement facility interface for dasd\n"
 130                    "Copyright 2003 IBM Corporation\n");