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/*
* IOCTL interface for SCLP
*
* Copyright IBM Corp. 2012
*
* Author: Michael Holzheu <holzheu@linux.vnet.ibm.com>
*/
#include <linux/compat.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/gfp.h>
#include <linux/module.h>
#include <linux/ioctl.h>
#include <linux/fs.h>
#include <asm/compat.h>
#include <asm/sclp_ctl.h>
#include <asm/sclp.h>
#include "sclp.h"
/*
* Supported command words
*/
static unsigned int sclp_ctl_sccb_wlist[] = {
0x00400002,
0x00410002,
};
/*
* Check if command word is supported
*/
static int sclp_ctl_cmdw_supported(unsigned int cmdw)
{
int i;
for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) {
if (cmdw == sclp_ctl_sccb_wlist[i])
return 1;
}
return 0;
}
static void __user *u64_to_uptr(u64 value)
{
if (is_compat_task())
return compat_ptr(value);
else
return (void __user *)(unsigned long)value;
}
/*
* Start SCLP request
*/
static int sclp_ctl_ioctl_sccb(void __user *user_area)
{
struct sclp_ctl_sccb ctl_sccb;
struct sccb_header *sccb;
unsigned long copied;
int rc;
if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb)))
return -EFAULT;
if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw))
return -EOPNOTSUPP;
sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
if (!sccb)
return -ENOMEM;
copied = PAGE_SIZE -
copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), PAGE_SIZE);
if (offsetof(struct sccb_header, length) +
sizeof(sccb->length) > copied || sccb->length > copied) {
rc = -EFAULT;
goto out_free;
}
if (sccb->length < 8) {
rc = -EINVAL;
goto out_free;
}
rc = sclp_sync_request(ctl_sccb.cmdw, sccb);
if (rc)
goto out_free;
if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length))
rc = -EFAULT;
out_free:
free_page((unsigned long) sccb);
return rc;
}
/*
* SCLP SCCB ioctl function
*/
static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
void __user *argp;
if (is_compat_task())
argp = compat_ptr(arg);
else
argp = (void __user *) arg;
switch (cmd) {
case SCLP_CTL_SCCB:
return sclp_ctl_ioctl_sccb(argp);
default: /* unknown ioctl number */
return -ENOTTY;
}
}
/*
* File operations
*/
static const struct file_operations sclp_ctl_fops = {
.owner = THIS_MODULE,
.open = nonseekable_open,
.unlocked_ioctl = sclp_ctl_ioctl,
.compat_ioctl = sclp_ctl_ioctl,
.llseek = no_llseek,
};
/*
* Misc device definition
*/
static struct miscdevice sclp_ctl_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "sclp",
.fops = &sclp_ctl_fops,
};
/*
* Register sclp_ctl misc device
*/
static int __init sclp_ctl_init(void)
{
return misc_register(&sclp_ctl_device);
}
module_init(sclp_ctl_init);
/*
* Deregister sclp_ctl misc device
*/
static void __exit sclp_ctl_exit(void)
{
misc_deregister(&sclp_ctl_device);
}
module_exit(sclp_ctl_exit);
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