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authorMichael Ernst <mernst@de.ibm.com>2008-04-17 07:46:01 +0200
committerHeiko Carstens <heiko.carstens@de.ibm.com>2008-04-17 07:46:57 +0200
commit8284fb19efa1f11ea8dd213e9e227fc1fcb20586 (patch)
treef91933a4ee9e253bd25c3a98df0d67ee946bb41e /drivers/s390
parentfe6173d9b33dba18ec462051750fb1b9abcd796d (diff)
[S390] cio: fix parallel cm_enable processing.
It is now possible to trigger cm_enable processing several times in parallel without causing a kernel panic. Signed-off-by: Michael Ernst <mernst@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/cio/chsc.c3
-rw-r--r--drivers/s390/cio/css.c10
2 files changed, 9 insertions, 4 deletions
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index b6a40c20780d..5de86908b0d0 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -766,7 +766,6 @@ chsc_secm(struct channel_subsystem *css, int enable)
if (!secm_area)
return -ENOMEM;
- mutex_lock(&css->mutex);
if (enable && !css->cm_enabled) {
css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
@@ -774,7 +773,6 @@ chsc_secm(struct channel_subsystem *css, int enable)
free_page((unsigned long)css->cub_addr1);
free_page((unsigned long)css->cub_addr2);
free_page((unsigned long)secm_area);
- mutex_unlock(&css->mutex);
return -ENOMEM;
}
}
@@ -795,7 +793,6 @@ chsc_secm(struct channel_subsystem *css, int enable)
free_page((unsigned long)css->cub_addr1);
free_page((unsigned long)css->cub_addr2);
}
- mutex_unlock(&css->mutex);
free_page((unsigned long)secm_area);
return ret;
}
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 3e829c827493..c1afab5f72d6 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -689,10 +689,14 @@ css_cm_enable_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct channel_subsystem *css = to_css(dev);
+ int ret;
if (!css)
return 0;
- return sprintf(buf, "%x\n", css->cm_enabled);
+ mutex_lock(&css->mutex);
+ ret = sprintf(buf, "%x\n", css->cm_enabled);
+ mutex_unlock(&css->mutex);
+ return ret;
}
static ssize_t
@@ -702,6 +706,7 @@ css_cm_enable_store(struct device *dev, struct device_attribute *attr,
struct channel_subsystem *css = to_css(dev);
int ret;
+ mutex_lock(&css->mutex);
switch (buf[0]) {
case '0':
ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
@@ -712,6 +717,7 @@ css_cm_enable_store(struct device *dev, struct device_attribute *attr,
default:
ret = -EINVAL;
}
+ mutex_unlock(&css->mutex);
return ret < 0 ? ret : count;
}
@@ -758,9 +764,11 @@ static int css_reboot_event(struct notifier_block *this,
struct channel_subsystem *css;
css = channel_subsystems[i];
+ mutex_lock(&css->mutex);
if (css->cm_enabled)
if (chsc_secm(css, 0))
ret = NOTIFY_BAD;
+ mutex_unlock(&css->mutex);
}
return ret;