[patch 4/8] vmcp cleanup

Martin Schwidefsky
2007-07-17T12:17:51Z

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From: Christian Borntraeger <borntraeger@de.ibm.com>

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>
---

drivers/s390/char/vmcp.c | 89 ++++++++++++++++++++++++++---------------------
drivers/s390/char/vmcp.h | 4 +-
2 files changed, 53 insertions(+), 40 deletions(-)

Index: quilt-2.6/drivers/s390/char/vmcp.c
===================================================================
--- quilt-2.6.orig/drivers/s390/char/vmcp.c
+++ quilt-2.6/drivers/s390/char/vmcp.c
@@ -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
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 *in
}

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
}
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
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
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
.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);
Index: quilt-2.6/drivers/s390/char/vmcp.h
===================================================================
--- quilt-2.6.orig/drivers/s390/char/vmcp.h
+++ quilt-2.6/drivers/s390/char/vmcp.h
@@ -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;
};