[S390] rework of channel measurement facility.

Fixes for several channel measurement facility bugs:
* Blocks copied from the hardware might not be consistent. Solve this
  by moving the copying into idle state and repeating the copying.
* avg_sample_interval changed with every read, even though no new block
  was available. Solve this by storing a timestamp when the last new
  block was received.
* Several locking issues.
* Measurements were not reenabled after a disconnected device became
  available again.
* Remove #defines for ioctls that were never implemented.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 8e0d1db..00be9a5 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -27,6 +27,7 @@
 	DEV_STATE_DISCONNECTED,
 	DEV_STATE_DISCONNECTED_SENSE_ID,
 	DEV_STATE_CMFCHANGE,
+	DEV_STATE_CMFUPDATE,
 	/* last element! */
 	NR_DEV_STATES
 };
@@ -118,5 +119,8 @@
 void ccw_device_set_timeout(struct ccw_device *, int);
 extern struct subchannel_id ccw_device_get_subchannel_id(struct ccw_device *);
 
+/* Channel measurement facility related */
 void retry_set_schib(struct ccw_device *cdev);
+void cmf_retry_copy_block(struct ccw_device *);
+int cmf_reenable(struct ccw_device *);
 #endif