[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>

drivers/s390/cio/device.h

@@ -27,6 +27,7 @@ enum dev_state {
 	DEV_STATE_DISCONNECTED,
 	DEV_STATE_DISCONNECTED_SENSE_ID,
 	DEV_STATE_CMFCHANGE,
+	DEV_STATE_CMFUPDATE,
 	/* last element! */
 	NR_DEV_STATES
 };
@@ -118,5 +119,8 @@ int ccw_device_stlck(struct ccw_device *);
 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

drivers/s390/cio/device_fsm.c

@@ -336,8 +336,11 @@ ccw_device_oper_notify(void *data)
 	if (!ret)
 		/* Driver doesn't want device back. */
 		ccw_device_do_unreg_rereg((void *)cdev);
-	else
+	else {
+		/* Reenable channel measurements, if needed. */
+		cmf_reenable(cdev);
 		wake_up(&cdev->private->wait_q);
+	}
 }
 
 /*
@@ -1095,6 +1098,13 @@ ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
 	dev_fsm_event(cdev, dev_event);
 }
 
+static void ccw_device_update_cmfblock(struct ccw_device *cdev,
+				       enum dev_event dev_event)
+{
+	cmf_retry_copy_block(cdev);
+	cdev->private->state = DEV_STATE_ONLINE;
+	dev_fsm_event(cdev, dev_event);
+}
 
 static void
 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
@@ -1249,6 +1259,12 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
 		[DEV_EVENT_TIMEOUT]	= ccw_device_change_cmfstate,
 		[DEV_EVENT_VERIFY]	= ccw_device_change_cmfstate,
 	},
+	[DEV_STATE_CMFUPDATE] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_update_cmfblock,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_update_cmfblock,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_update_cmfblock,
+		[DEV_EVENT_VERIFY]	= ccw_device_update_cmfblock,
+	},
 };
 
 /*

include/asm-s390/cmb.h

@@ -44,10 +44,6 @@ struct cmbdata {
 #define BIODASDCMFENABLE	_IO(DASD_IOCTL_LETTER,32)
 /* enable channel measurement */
 #define BIODASDCMFDISABLE	_IO(DASD_IOCTL_LETTER,33)
-/* reset channel measurement block */
-#define BIODASDRESETCMB		_IO(DASD_IOCTL_LETTER,34)
-/* read channel measurement data */
-#define BIODASDREADCMB		_IOWR(DASD_IOCTL_LETTER,32,__u64)
 /* read channel measurement data */
 #define BIODASDREADALLCMB	_IOWR(DASD_IOCTL_LETTER,33,struct cmbdata)