Commit b730f3a9 authored by Sebastian Ott's avatar Sebastian Ott Committed by Martin Schwidefsky
Browse files

[S390] cio: add lock to struct channel_path 



Serialize access to members of struct channel_path with a mutex.

Signed-off-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 74b6127e

drivers/s390/cio/chp.c

+23 −12
Original line number Diff line number Diff line 
/*

 *  drivers/s390/cio/chp.c

 *

 *    Copyright IBM Corp. 1999,2007

 *    Copyright IBM Corp. 1999,2010

 *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)

 *		 Arnd Bergmann (arndb@de.ibm.com)

 *		 Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
@@ -241,11 +241,13 @@ static ssize_t chp_status_show(struct device *dev, 
			       struct device_attribute *attr, char *buf)

{

	struct channel_path *chp = to_channelpath(dev);

	int status;



	if (!chp)

		return 0;

	return (chp_get_status(chp->chpid) ? sprintf(buf, "online\n") :

		sprintf(buf, "offline\n"));

	mutex_lock(&chp->lock);

	status = chp->state;

	mutex_unlock(&chp->lock);



	return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");

}



static ssize_t chp_status_write(struct device *dev,
@@ -261,15 +263,18 @@ static ssize_t chp_status_write(struct device *dev, 
	if (!num_args)

		return count;



	if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1"))

	if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) {

		mutex_lock(&cp->lock);

		error = s390_vary_chpid(cp->chpid, 1);

	else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0"))

		mutex_unlock(&cp->lock);

	} else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) {

		mutex_lock(&cp->lock);

		error = s390_vary_chpid(cp->chpid, 0);

	else

		mutex_unlock(&cp->lock);

	} else

		error = -EINVAL;



	return error < 0 ? error : count;



}



static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
@@ -315,10 +320,12 @@ static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr, 
			     char *buf)

{

	struct channel_path *chp = to_channelpath(dev);

	u8 type;



	if (!chp)

		return 0;

	return sprintf(buf, "%x\n", chp->desc.desc);

	mutex_lock(&chp->lock);

	type = chp->desc.desc;

	mutex_unlock(&chp->lock);

	return sprintf(buf, "%x\n", type);

}



static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
@@ -395,6 +402,7 @@ int chp_new(struct chp_id chpid) 
	chp->state = 1;

	chp->dev.parent = &channel_subsystems[chpid.cssid]->device;

	chp->dev.release = chp_release;

	mutex_init(&chp->lock);



	/* Obtain channel path description and fill it in. */

	ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc);
@@ -464,7 +472,10 @@ void *chp_get_chp_desc(struct chp_id chpid) 
	desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);

	if (!desc)

		return NULL;



	mutex_lock(&chp->lock);

	memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));

	mutex_unlock(&chp->lock);

	return desc;

}

drivers/s390/cio/chp.h

+4 −2
Original line number Diff line number Diff line 
/*

 *  drivers/s390/cio/chp.h

 *

 *    Copyright IBM Corp. 2007

 *    Copyright IBM Corp. 2007,2010

 *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>

 */
@@ -10,6 +10,7 @@ 


#include <linux/types.h>

#include <linux/device.h>

#include <linux/mutex.h>

#include <asm/chpid.h>

#include "chsc.h"

#include "css.h"
@@ -40,14 +41,15 @@ static inline int chp_test_bit(u8 *bitmap, int num) 




struct channel_path {

	struct device dev;

	struct chp_id chpid;

	struct mutex lock; /* Serialize access to below members. */

	int state;

	struct channel_path_desc desc;

	/* Channel-measurement related stuff: */

	int cmg;

	int shared;

	void *cmg_chars;

	struct device dev;

};



int chp_get_status(struct chp_id chpid);