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>
This commit is contained in:
Sebastian Ott 2015-09-07 19:50:25 +02:00 committed by Martin Schwidefsky
parent 3c4aac86cb
commit 279b8f9a0f

View File

@ -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)
{