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[S390] cio: add lock to struct channel_path 

Serialize access to members of struct channel_path with a mutex.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott 2010-10-25 16:10:27 +02:00 committed by Martin Schwidefsky
parent 74b6127e6c
commit b730f3a933
2 changed files with 27 additions and 14 deletions
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35
drivers/s390/cio/chp.c
View File

@ -1,7 +1,7 @@
/*
* 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;
}

6
drivers/s390/cio/chp.h
View File

@ -1,7 +1,7 @@
/*
* 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);