libata: separate out ata_ncq_enabled()

Separate out ata_ncq_enabled().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

@@ -315,9 +315,7 @@ int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
 	tf->flags |= tf_flags;
 
-	if ((dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ_OFF |
-			   ATA_DFLAG_NCQ)) == ATA_DFLAG_NCQ &&
-	    likely(tag != ATA_TAG_INTERNAL)) {
+	if (ata_ncq_enabled(dev) && likely(tag != ATA_TAG_INTERNAL)) {
 		/* yay, NCQ */
 		if (!lba_48_ok(block, n_block))
 			return -ERANGE;

include/linux/libata.h

@@ -1033,6 +1033,21 @@ static inline u8 ata_chk_status(struct ata_port *ap)
 	return ap->ops->check_status(ap);
 }
 
+/**
+ *	ata_ncq_enabled - Test whether NCQ is enabled
+ *	@dev: ATA device to test for
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ *
+ *	RETURNS:
+ *	1 if NCQ is enabled for @dev, 0 otherwise.
+ */
+static inline int ata_ncq_enabled(struct ata_device *dev)
+{
+	return (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ_OFF |
+			      ATA_DFLAG_NCQ)) == ATA_DFLAG_NCQ;
+}
 
 /**
  *	ata_pause - Flush writes and pause 400 nanoseconds.