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authorSebastian Ott <sebott@linux.vnet.ibm.com>2015-09-07 19:50:25 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-10-14 14:32:02 +0200
commit279b8f9a0f3ea3399764047d487dfdd8f7bc9795 (patch)
tree09a521026818d27426df90c9e2c288ce759d4cd3 /drivers/s390
parent3c4aac86cbb3389d74152a83c89cf3a31fd7cc0b (diff)
downloadlinux-279b8f9a0f3ea3399764047d487dfdd8f7bc9795.tar.bz2
s390/cio: cleanup cmb_enable sysfs attr
Ensure that we hold the ccwlock when accessing private data. Return errors that occur during measurement enabling to userspace. Apply some cleanups while at it. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/cio/cmf.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/s390/cio/cmf.c b/drivers/s390/cio/cmf.c
index 23054f8fa9fc..3543c486dcdc 100644
--- a/drivers/s390/cio/cmf.c
+++ b/drivers/s390/cio/cmf.c
@@ -1171,23 +1171,28 @@ static ssize_t cmb_enable_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
- return sprintf(buf, "%d\n", to_ccwdev(dev)->private->cmb ? 1 : 0);
+ struct ccw_device *cdev = to_ccwdev(dev);
+ int enabled;
+
+ spin_lock_irq(cdev->ccwlock);
+ enabled = !!cdev->private->cmb;
+ spin_unlock_irq(cdev->ccwlock);
+
+ return sprintf(buf, "%d\n", enabled);
}
static ssize_t cmb_enable_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t c)
{
- struct ccw_device *cdev;
- int ret;
+ struct ccw_device *cdev = to_ccwdev(dev);
unsigned long val;
+ int ret;
ret = kstrtoul(buf, 16, &val);
if (ret)
return ret;
- cdev = to_ccwdev(dev);
-
switch (val) {
case 0:
ret = disable_cmf(cdev);
@@ -1195,12 +1200,13 @@ static ssize_t cmb_enable_store(struct device *dev,
case 1:
ret = enable_cmf(cdev);
break;
+ default:
+ ret = -EINVAL;
}
- return c;
+ return ret ? ret : c;
}
-
-DEVICE_ATTR(cmb_enable, 0644, cmb_enable_show, cmb_enable_store);
+DEVICE_ATTR_RW(cmb_enable);
int ccw_set_cmf(struct ccw_device *cdev, int enable)
{