diff options
| author | Sebastian Ott | 2015-09-07 19:50:25 +0200 |
|---|---|---|
| committer | Martin Schwidefsky | 2015-10-14 14:32:02 +0200 |
| commit | 279b8f9a0f3ea3399764047d487dfdd8f7bc9795 (patch) | |
| tree | 09a521026818d27426df90c9e2c288ce759d4cd3 | |
| parent | 3c4aac86cbb3389d74152a83c89cf3a31fd7cc0b (diff) | |
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>
| -rw-r--r-- | drivers/s390/cio/cmf.c | 22 |
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) { |