diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 5c84fb5c3372..695d33df3df5 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1525,6 +1525,15 @@ static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
 	complete(waiting);
 }
 
+static bool ata_valid_internal_tag(struct ata_port *ap, struct ata_device *dev,
+				   unsigned int tag)
+{
+	if (!ap->scsi_host)
+		return !test_and_set_bit(tag, &ap->sas_tag_allocated);
+	return !dev->sdev ||
+	       !blk_queue_find_tag(dev->sdev->request_queue, tag);
+}
+
 /**
  *	ata_exec_internal_sg - execute libata internal command
  *	@dev: Device to which the command is sent
@@ -1585,8 +1594,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	else
 		tag = 0;
 
-	if (test_and_set_bit(tag, &ap->qc_allocated))
-		BUG();
+	BUG_ON(!ata_valid_internal_tag(ap, dev, tag));
 	qc = __ata_qc_from_tag(ap, tag);
 
 	qc->tag = tag;
@@ -4737,27 +4745,23 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
  *	None.
  */
 
-static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
+static struct ata_queued_cmd *sas_ata_qc_new(struct ata_port *ap)
 {
 	struct ata_queued_cmd *qc = NULL;
 	unsigned int max_queue = ap->host->n_tags;
 	unsigned int i, tag;
 
-	/* no command while frozen */
-	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
-		return NULL;
-
-	for (i = 0, tag = ap->last_tag + 1; i < max_queue; i++, tag++) {
+	for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) {
 		tag = tag < max_queue ? tag : 0;
 
 		/* the last tag is reserved for internal command. */
 		if (tag == ATA_TAG_INTERNAL)
 			continue;
 
-		if (!test_and_set_bit(tag, &ap->qc_allocated)) {
+		if (!test_and_set_bit(tag, &ap->sas_tag_allocated)) {
 			qc = __ata_qc_from_tag(ap, tag);
 			qc->tag = tag;
-			ap->last_tag = tag;
+			ap->sas_last_tag = tag;
 			break;
 		}
 	}
@@ -4765,6 +4769,24 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
 	return qc;
 }
 
+static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap, int blktag)
+{
+	struct ata_queued_cmd *qc;
+
+	/* no command while frozen */
+	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
+		return NULL;
+
+	/* SATA will directly use block tag. libsas need its own tag management */
+	if (ap->scsi_host) {
+		qc = __ata_qc_from_tag(ap, blktag);
+		qc->tag = blktag;
+		return qc;
+	}
+
+	return sas_ata_qc_new(ap);
+}
+
 /**
  *	ata_qc_new_init - Request an available ATA command, and initialize it
  *	@dev: Device from whom we request an available command structure
@@ -4773,12 +4795,12 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
  *	None.
  */
 
-struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
+struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int blktag)
 {
 	struct ata_port *ap = dev->link->ap;
 	struct ata_queued_cmd *qc;
 
-	qc = ata_qc_new(ap);
+	qc = ata_qc_new(ap, blktag);
 	if (qc) {
 		qc->scsicmd = NULL;
 		qc->ap = ap;
@@ -4800,6 +4822,12 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
  *	LOCKING:
  *	spin_lock_irqsave(host lock)
  */
+static void sas_ata_qc_free(unsigned int tag, struct ata_port *ap)
+{
+	if (!ap->scsi_host)
+		clear_bit(tag, &ap->sas_tag_allocated);
+}
+
 void ata_qc_free(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap;
@@ -4812,7 +4840,7 @@ void ata_qc_free(struct ata_queued_cmd *qc)
 	tag = qc->tag;
 	if (likely(ata_tag_valid(tag))) {
 		qc->tag = ATA_TAG_POISON;
-		clear_bit(tag, &ap->qc_allocated);
+		sas_ata_qc_free(tag, ap);
 	}
 }
 
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index e364e86e84d7..94339c2aed1b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -756,7 +756,7 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
 {
 	struct ata_queued_cmd *qc;
 
-	qc = ata_qc_new_init(dev);
+	qc = ata_qc_new_init(dev, cmd->request->tag);
 	if (qc) {
 		qc->scsicmd = cmd;
 		qc->scsidone = cmd->scsi_done;
@@ -3666,6 +3666,8 @@ int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
 		 */
 		shost->max_host_blocked = 1;
 
+		scsi_init_shared_tag_map(shost, host->n_tags);
+
 		rc = scsi_add_host_with_dma(ap->scsi_host,
 						&ap->tdev, ap->host->dev);
 		if (rc)
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 5f4e0cca56ec..40405135bbb6 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -63,7 +63,7 @@ extern struct ata_link *ata_dev_phys_link(struct ata_device *dev);
 extern void ata_force_cbl(struct ata_port *ap);
 extern u64 ata_tf_to_lba(const struct ata_taskfile *tf);
 extern u64 ata_tf_to_lba48(const struct ata_taskfile *tf);
-extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
+extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag);
 extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
 			   u64 block, u32 n_block, unsigned int tf_flags,
 			   unsigned int tag);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2d182413b1db..f23454762717 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -821,10 +821,10 @@ struct ata_port {
 	unsigned int		cbl;	/* cable type; ATA_CBL_xxx */
 
 	struct ata_queued_cmd	qcmd[ATA_MAX_QUEUE];
-	unsigned long		qc_allocated;
+	unsigned long		sas_tag_allocated; /* for sas tag allocation only */
 	unsigned int		qc_active;
 	int			nr_active_links; /* #links with active qcs */
-	unsigned int		last_tag;	/* track next tag hw expects */
+	unsigned int		sas_last_tag;	/* track next tag hw expects */
 
 	struct ata_link		link;		/* host default link */
 	struct ata_link		*slave_link;	/* see ata_slave_link_init() */
@@ -1344,6 +1344,7 @@ extern struct device_attribute *ata_common_sdev_attrs[];
 	.ioctl			= ata_scsi_ioctl,		\
 	.queuecommand		= ata_scsi_queuecmd,		\
 	.can_queue		= ATA_DEF_QUEUE,		\
+	.tag_alloc_policy	= BLK_TAG_ALLOC_RR,		\
 	.this_id		= ATA_SHT_THIS_ID,		\
 	.cmd_per_lun		= ATA_SHT_CMD_PER_LUN,		\
 	.emulated		= ATA_SHT_EMULATED,		\