drivers/s390/block/dasd_cmb.c

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