s390/cio: use device_lock during cmb activation
Hold the device_lock during [de]activation of the channel measurement
block to synchronize concurrent usage of these functions.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/cmb.h b/arch/s390/include/asm/cmb.h
index 806eac1..ed2630c 100644
--- a/arch/s390/include/asm/cmb.h
+++ b/arch/s390/include/asm/cmb.h
@@ -6,6 +6,7 @@
struct ccw_device;
extern int enable_cmf(struct ccw_device *cdev);
extern int disable_cmf(struct ccw_device *cdev);
+extern int __disable_cmf(struct ccw_device *cdev);
extern u64 cmf_read(struct ccw_device *cdev, int index);
extern int cmf_readall(struct ccw_device *cdev, struct cmbdata *data);