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Commit d9d119f1 authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Martin Schwidefsky
Browse files

[S390] vmcp cleanup 



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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 6cbed91a

drivers/s390/char/vmcp.c

+51 −38
Original line number Diff line number Diff line 
/*

 * 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);

}
@@ -63,24 +65,24 @@ vmcp_read(struct file *file, char __user * buff, size_t count, loff_t * ppos) 
	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));



	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;

}
@@ -103,7 +105,7 @@ 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;

	}
@@ -112,15 +114,14 @@ vmcp_write(struct file *file, const char __user * buff, size_t count, 
						| __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_size = cpcmd(cmd, session->response, session->bufsize,

				   &session->resp_code);

	up(&session->mutex);

	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);

	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);

drivers/s390/char/vmcp.h

+2 −2
Original line number Diff line number Diff line
@@ -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;

};