libata: implement protocol tests

Implement protocol tests - ata_is_atapi(), ata_is_nodata(),
ata_is_pio(), ata_is_dma(), ata_is_ncq() and ata_is_data() and use
them to replace is_atapi_taskfile() and hard coded protocol tests.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/sata_sil.c b/drivers/ata/sata_sil.c
index f5119bf..0b8191b 100644
--- a/drivers/ata/sata_sil.c
+++ b/drivers/ata/sata_sil.c
@@ -416,15 +416,14 @@
 		 */
 
 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
-		 * The flag was turned on only for atapi devices.
-		 * No need to check is_atapi_taskfile(&qc->tf) again.
+		 * The flag was turned on only for atapi devices.  No
+		 * need to check ata_is_atapi(qc->tf.protocol) again.
 		 */
 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
 			goto err_hsm;
 		break;
 	case HSM_ST_LAST:
-		if (qc->tf.protocol == ATA_PROT_DMA ||
-		    qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
+		if (ata_is_dma(qc->tf.protocol)) {
 			/* clear DMA-Start bit */
 			ap->ops->bmdma_stop(qc);
 
@@ -451,8 +450,7 @@
 	/* kick HSM in the ass */
 	ata_hsm_move(ap, qc, status, 0);
 
-	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
-				       qc->tf.protocol == ATA_PROT_ATAPI_DMA))
+	if (unlikely(qc->err_mask) && ata_is_dma(qc->tf.protocol))
 		ata_ehi_push_desc(ehi, "BMDMA2 stat 0x%x", bmdma2);
 
 	return;