[PATCH] s390: add vmcp interface
Add interface to issue VM control program commands. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Этот коммит содержится в:
Christian Borntraeger
коммит произвёл
Linus Torvalds
Linus Torvalds
родитель
77fa22450d
Коммит
6b979de395
219
drivers/s390/char/vmcp.c
Обычный файл
219
drivers/s390/char/vmcp.c
Обычный файл
@@ -0,0 +1,219 @@
|
||||
/*
|
||||
* Copyright (C) 2004,2005 IBM Corporation
|
||||
* Interface implementation for communication with the v/VM control program
|
||||
* Author(s): Christian Borntraeger <cborntra@de.ibm.com>
|
||||
*
|
||||
*
|
||||
* z/VMs CP offers the possibility to issue commands via the diagnose code 8
|
||||
* this driver implements a character device that issues these commands and
|
||||
* returns the answer of CP.
|
||||
|
||||
* The idea of this driver is based on cpint from Neale Ferguson and #CP in CMS
|
||||
*/
|
||||
|
||||
#include <linux/fs.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/miscdevice.h>
|
||||
#include <linux/module.h>
|
||||
#include <asm/cpcmd.h>
|
||||
#include <asm/debug.h>
|
||||
#include <asm/uaccess.h>
|
||||
#include "vmcp.h"
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_AUTHOR("Christian Borntraeger <cborntra@de.ibm.com>");
|
||||
MODULE_DESCRIPTION("z/VM CP interface");
|
||||
|
||||
static debug_info_t *vmcp_debug;
|
||||
|
||||
static int vmcp_open(struct inode *inode, struct file *file)
|
||||
{
|
||||
struct vmcp_session *session;
|
||||
|
||||
if (!capable(CAP_SYS_ADMIN))
|
||||
return -EPERM;
|
||||
|
||||
session = kmalloc(sizeof(*session), GFP_KERNEL);
|
||||
if (!session)
|
||||
return -ENOMEM;
|
||||
session->bufsize = PAGE_SIZE;
|
||||
session->response = NULL;
|
||||
session->resp_size = 0;
|
||||
init_MUTEX(&session->mutex);
|
||||
file->private_data = session;
|
||||
return nonseekable_open(inode, file);
|
||||
}
|
||||
|
||||
static int vmcp_release(struct inode *inode, struct file *file)
|
||||
{
|
||||
struct vmcp_session *session;
|
||||
|
||||
session = (struct vmcp_session *)file->private_data;
|
||||
file->private_data = NULL;
|
||||
free_pages((unsigned long)session->response, get_order(session->bufsize));
|
||||
kfree(session);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
vmcp_read(struct file *file, char __user * buff, size_t count, loff_t * ppos)
|
||||
{
|
||||
size_t tocopy;
|
||||
struct vmcp_session *session;
|
||||
|
||||
session = (struct vmcp_session *)file->private_data;
|
||||
if (down_interruptible(&session->mutex))
|
||||
return -ERESTARTSYS;
|
||||
if (!session->response) {
|
||||
up(&session->mutex);
|
||||
return 0;
|
||||
}
|
||||
if (*ppos > session->resp_size) {
|
||||
up(&session->mutex);
|
||||
return 0;
|
||||
}
|
||||
tocopy = min(session->resp_size - (size_t) (*ppos), count);
|
||||
tocopy = min(tocopy,session->bufsize - (size_t) (*ppos));
|
||||
|
||||
if (copy_to_user(buff, session->response + (*ppos), tocopy)) {
|
||||
up(&session->mutex);
|
||||
return -EFAULT;
|
||||
}
|
||||
up(&session->mutex);
|
||||
*ppos += tocopy;
|
||||
return tocopy;
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
vmcp_write(struct file *file, const char __user * buff, size_t count,
|
||||
loff_t * ppos)
|
||||
{
|
||||
char *cmd;
|
||||
struct vmcp_session *session;
|
||||
|
||||
if (count > 240)
|
||||
return -EINVAL;
|
||||
cmd = kmalloc(count + 1, GFP_KERNEL);
|
||||
if (!cmd)
|
||||
return -ENOMEM;
|
||||
if (copy_from_user(cmd, buff, count)) {
|
||||
kfree(cmd);
|
||||
return -EFAULT;
|
||||
}
|
||||
cmd[count] = '\0';
|
||||
session = (struct vmcp_session *)file->private_data;
|
||||
if (down_interruptible(&session->mutex))
|
||||
return -ERESTARTSYS;
|
||||
if (!session->response)
|
||||
session->response = (char *)__get_free_pages(GFP_KERNEL
|
||||
| __GFP_REPEAT | GFP_DMA,
|
||||
get_order(session->bufsize));
|
||||
if (!session->response) {
|
||||
up(&session->mutex);
|
||||
kfree(cmd);
|
||||
return -ENOMEM;
|
||||
}
|
||||
debug_text_event(vmcp_debug, 1, cmd);
|
||||
session->resp_size = cpcmd(cmd, session->response,
|
||||
session->bufsize,
|
||||
&session->resp_code);
|
||||
up(&session->mutex);
|
||||
kfree(cmd);
|
||||
*ppos = 0; /* reset the file pointer after a command */
|
||||
return count;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* These ioctls are available, as the semantics of the diagnose 8 call
|
||||
* does not fit very well into a Linux call. Diagnose X'08' is described in
|
||||
* CP Programming Services SC24-6084-00
|
||||
*
|
||||
* VMCP_GETCODE: gives the CP return code back to user space
|
||||
* VMCP_SETBUF: sets the response buffer for the next write call. diagnose 8
|
||||
* expects adjacent pages in real storage and to make matters worse, we
|
||||
* dont know the size of the response. Therefore we default to PAGESIZE and
|
||||
* let userspace to change the response size, if userspace expects a bigger
|
||||
* response
|
||||
*/
|
||||
static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
||||
{
|
||||
struct vmcp_session *session;
|
||||
int temp;
|
||||
|
||||
session = (struct vmcp_session *)file->private_data;
|
||||
if (down_interruptible(&session->mutex))
|
||||
return -ERESTARTSYS;
|
||||
switch (cmd) {
|
||||
case VMCP_GETCODE:
|
||||
temp = session->resp_code;
|
||||
up(&session->mutex);
|
||||
return put_user(temp, (int __user *)arg);
|
||||
case VMCP_SETBUF:
|
||||
free_pages((unsigned long)session->response,
|
||||
get_order(session->bufsize));
|
||||
session->response=NULL;
|
||||
temp = get_user(session->bufsize, (int __user *)arg);
|
||||
if (get_order(session->bufsize) > 8) {
|
||||
session->bufsize = PAGE_SIZE;
|
||||
temp = -EINVAL;
|
||||
}
|
||||
up(&session->mutex);
|
||||
return temp;
|
||||
case VMCP_GETSIZE:
|
||||
temp = session->resp_size;
|
||||
up(&session->mutex);
|
||||
return put_user(temp, (int __user *)arg);
|
||||
default:
|
||||
up(&session->mutex);
|
||||
return -ENOIOCTLCMD;
|
||||
}
|
||||
}
|
||||
|
||||
static struct file_operations vmcp_fops = {
|
||||
.owner = THIS_MODULE,
|
||||
.open = &vmcp_open,
|
||||
.release = &vmcp_release,
|
||||
.read = &vmcp_read,
|
||||
.llseek = &no_llseek,
|
||||
.write = &vmcp_write,
|
||||
.unlocked_ioctl = &vmcp_ioctl,
|
||||
.compat_ioctl = &vmcp_ioctl
|
||||
};
|
||||
|
||||
static struct miscdevice vmcp_dev = {
|
||||
.name = "vmcp",
|
||||
.minor = MISC_DYNAMIC_MINOR,
|
||||
.fops = &vmcp_fops,
|
||||
};
|
||||
|
||||
static int __init vmcp_init(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
if (!MACHINE_IS_VM) {
|
||||
printk(KERN_WARNING
|
||||
"z/VM CP interface is only available under z/VM\n");
|
||||
return -ENODEV;
|
||||
}
|
||||
ret = misc_register(&vmcp_dev);
|
||||
if (!ret)
|
||||
printk(KERN_INFO "z/VM CP interface loaded\n");
|
||||
else
|
||||
printk(KERN_WARNING
|
||||
"z/VM CP interface not loaded. Could not register misc device.\n");
|
||||
vmcp_debug = debug_register("vmcp", 0, 1, 240);
|
||||
debug_register_view(vmcp_debug, &debug_hex_ascii_view);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void __exit vmcp_exit(void)
|
||||
{
|
||||
WARN_ON(misc_deregister(&vmcp_dev) != 0);
|
||||
debug_unregister(vmcp_debug);
|
||||
printk(KERN_INFO "z/VM CP interface unloaded.\n");
|
||||
}
|
||||
|
||||
module_init(vmcp_init);
|
||||
module_exit(vmcp_exit);
|
||||
Ссылка в новой задаче
Block a user