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[S390] vmcp cleanup

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A number of small changes to vmcp:
 - Change preferred email address.
 - Use PRINT_xxx machros from debug.h like most s390 drivers, define
   "vmcp:" as PRINTK_HEADER and wrap error message at column 80.
 - Add error number to error message.
 - Update copyright, as I touched this file.
 - Small whitespace diff.
 - Use mutex instead of semaphore (Thanks Heiko for the patch)
 - Don't register debug feature on failure.
 - Check debug feature registration on init to avoid a potential oops
   on unload if the debug feature could not be registered--> 2 more
   messages.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Christian Borntraeger 2007-07-17 13:36:05 +02:00 committed by Martin Schwidefsky
parent 6cbed91ab7
commit d9d119f12f
2 changed files with 53 additions and 40 deletions
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89
drivers/s390/char/vmcp.c
View file

@ -1,7 +1,7 @@
/*
* Copyright (C) 2004,2005 IBM Corporation
* Copyright IBM Corp. 2004,2007
* Interface implementation for communication with the z/VM control program
* Author(s): Christian Borntraeger <cborntra@de.ibm.com>
* Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
*
*
* z/VMs CP offers the possibility to issue commands via the diagnose code 8
@ -22,9 +22,11 @@
#include "vmcp.h"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Borntraeger <cborntra@de.ibm.com>");
MODULE_AUTHOR("Christian Borntraeger <borntraeger@de.ibm.com>");
MODULE_DESCRIPTION("z/VM CP interface");
#define PRINTK_HEADER "vmcp: "
static debug_info_t *vmcp_debug;
static int vmcp_open(struct inode *inode, struct file *file)
@ -40,7 +42,7 @@ static int vmcp_open(struct inode *inode, struct file *file)
session->bufsize = PAGE_SIZE;
session->response = NULL;
session->resp_size = 0;
init_MUTEX(&session->mutex);
mutex_init(&session->mutex);
file->private_data = session;
return nonseekable_open(inode, file);
}
@ -57,37 +59,37 @@ static int vmcp_release(struct inode *inode, struct file *file)
}
static ssize_t
vmcp_read(struct file *file, char __user * buff, size_t count, loff_t * ppos)
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))
if (mutex_lock_interruptible(&session->mutex))
return -ERESTARTSYS;
if (!session->response) {
up(&session->mutex);
mutex_unlock(&session->mutex);
return 0;
}
if (*ppos > session->resp_size) {
up(&session->mutex);
mutex_unlock(&session->mutex);
return 0;
}
tocopy = min(session->resp_size - (size_t) (*ppos), count);
tocopy = min(tocopy,session->bufsize - (size_t) (*ppos));
tocopy = min(tocopy, session->bufsize - (size_t) (*ppos));
if (copy_to_user(buff, session->response + (*ppos), tocopy)) {
up(&session->mutex);
mutex_unlock(&session->mutex);
return -EFAULT;
}
up(&session->mutex);
mutex_unlock(&session->mutex);
*ppos += tocopy;
return tocopy;
}
static ssize_t
vmcp_write(struct file *file, const char __user * buff, size_t count,
loff_t * ppos)
vmcp_write(struct file *file, const char __user *buff, size_t count,
loff_t *ppos)
{
char *cmd;
struct vmcp_session *session;
@ -103,24 +105,23 @@ vmcp_write(struct file *file, const char __user * buff, size_t count,
}
cmd[count] = '\0';
session = (struct vmcp_session *)file->private_data;
if (down_interruptible(&session->mutex)) {
if (mutex_lock_interruptible(&session->mutex)) {
kfree(cmd);
return -ERESTARTSYS;
}
if (!session->response)
session->response = (char *)__get_free_pages(GFP_KERNEL
| __GFP_REPEAT | GFP_DMA,
| __GFP_REPEAT | GFP_DMA,
get_order(session->bufsize));
if (!session->response) {
up(&session->mutex);
mutex_unlock(&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);
session->resp_size = cpcmd(cmd, session->response, session->bufsize,
&session->resp_code);
mutex_unlock(&session->mutex);
kfree(cmd);
*ppos = 0; /* reset the file pointer after a command */
return count;
@ -145,12 +146,12 @@ static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
int temp;
session = (struct vmcp_session *)file->private_data;
if (down_interruptible(&session->mutex))
if (mutex_lock_interruptible(&session->mutex))
return -ERESTARTSYS;
switch (cmd) {
case VMCP_GETCODE:
temp = session->resp_code;
up(&session->mutex);
mutex_unlock(&session->mutex);
return put_user(temp, (int __user *)arg);
case VMCP_SETBUF:
free_pages((unsigned long)session->response,
@ -161,14 +162,14 @@ static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
session->bufsize = PAGE_SIZE;
temp = -EINVAL;
}
up(&session->mutex);
mutex_unlock(&session->mutex);
return temp;
case VMCP_GETSIZE:
temp = session->resp_size;
up(&session->mutex);
mutex_unlock(&session->mutex);
return put_user(temp, (int __user *)arg);
default:
up(&session->mutex);
mutex_unlock(&session->mutex);
return -ENOIOCTLCMD;
}
}
@ -180,7 +181,7 @@ static const struct file_operations vmcp_fops = {
.read = vmcp_read,
.write = vmcp_write,
.unlocked_ioctl = vmcp_ioctl,
.compat_ioctl = vmcp_ioctl
.compat_ioctl = vmcp_ioctl,
};
static struct miscdevice vmcp_dev = {
@ -194,26 +195,38 @@ 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");
PRINT_WARN("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", 1, 1, 240);
debug_register_view(vmcp_debug, &debug_hex_ascii_view);
return ret;
if (!vmcp_debug) {
PRINT_ERR("z/VM CP interface not loaded. Could not register "
"debug feature\n");
return -ENOMEM;
}
ret = debug_register_view(vmcp_debug, &debug_hex_ascii_view);
if (ret) {
PRINT_ERR("z/VM CP interface not loaded. Could not register "
"debug feature view. Error code: %d\n", ret);
debug_unregister(vmcp_debug);
return ret;
}
ret = misc_register(&vmcp_dev);
if (ret) {
PRINT_ERR("z/VM CP interface not loaded. Could not register "
"misc device. Error code: %d\n", ret);
debug_unregister(vmcp_debug);
return ret;
}
PRINT_INFO("z/VM CP interface loaded\n");
return 0;
}
static void __exit vmcp_exit(void)
{
WARN_ON(misc_deregister(&vmcp_dev) != 0);
misc_deregister(&vmcp_dev);
debug_unregister(vmcp_debug);
printk(KERN_INFO "z/VM CP interface unloaded.\n");
PRINT_INFO("z/VM CP interface unloaded.\n");
}
module_init(vmcp_init);

4
drivers/s390/char/vmcp.h
View file

@ -12,8 +12,8 @@
* The idea of this driver is based on cpint from Neale Ferguson
*/
#include <asm/semaphore.h>
#include <linux/ioctl.h>
#include <linux/mutex.h>
#define VMCP_GETCODE _IOR(0x10, 1, int)
#define VMCP_SETBUF _IOW(0x10, 2, int)
@ -26,5 +26,5 @@ struct vmcp_session {
int resp_code;
/* As we use copy_from/to_user, which might *
* sleep and cannot use a spinlock */
struct semaphore mutex;
struct mutex mutex;
};