libata: move sas ata tag allocation to libata-scsi.c

Basically move the sas ata tag allocation to libata-scsi.c to make it clear
these staffs are just for sas.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 46 insertions, 77 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 695d33df3df5..d626605ac8f7 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1525,15 +1525,6 @@ 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
@@ -1594,7 +1585,6 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	else
 		tag = 0;
 
-	BUG_ON(!ata_valid_internal_tag(ap, dev, tag));
 	qc = __ata_qc_from_tag(ap, tag);
 
 	qc->tag = tag;
@@ -4734,80 +4724,36 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
 }
 
 /**
- *	ata_qc_new - Request an available ATA command, for queueing
- *	@ap: target port
- *
- *	Some ATA host controllers may implement a queue depth which is less
- *	than ATA_MAX_QUEUE. So we shouldn't allocate a tag which is beyond
- *	the hardware limitation.
+ *	ata_qc_new_init - Request an available ATA command, and initialize it
+ *	@dev: Device from whom we request an available command structure
  *
  *	LOCKING:
  *	None.
  */
 
-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;
-
-	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->sas_tag_allocated)) {
-			qc = __ata_qc_from_tag(ap, tag);
-			qc->tag = tag;
-			ap->sas_last_tag = tag;
-			break;
-		}
-	}
-
-	return qc;
-}
-
-static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap, int blktag)
+struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
 {
+	struct ata_port *ap = dev->link->ap;
 	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;
+	/* libsas case */
+	if (!ap->scsi_host) {
+		tag = ata_sas_allocate_tag(ap);
+		if (tag < 0)
+			return NULL;
 	}
 
-	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
- *
- *	LOCKING:
- *	None.
- */
-
-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, blktag);
-	if (qc) {
-		qc->scsicmd = NULL;
-		qc->ap = ap;
-		qc->dev = dev;
+	qc = __ata_qc_from_tag(ap, tag);
+	qc->tag = tag;
+	qc->scsicmd = NULL;
+	qc->ap = ap;
+	qc->dev = dev;
 
-		ata_qc_reinit(qc);
-	}
+	ata_qc_reinit(qc);
 
 	return qc;
 }
@@ -4822,12 +4768,6 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int blktag)
  *	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;
@@ -4840,7 +4780,8 @@ void ata_qc_free(struct ata_queued_cmd *qc)
 	tag = qc->tag;
 	if (likely(ata_tag_valid(tag))) {
 		qc->tag = ATA_TAG_POISON;
-		sas_ata_qc_free(tag, ap);
+		if (!ap->scsi_host)
+			ata_sas_free_tag(tag, ap);
 	}
 }
 
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 94339c2aed1b..59c9d721b347 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3666,7 +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);
+		if (scsi_init_shared_tag_map(shost, host->n_tags))
+			goto err_add;
 
 		rc = scsi_add_host_with_dma(ap->scsi_host,
 						&ap->tdev, ap->host->dev);
@@ -4230,3 +4231,28 @@ int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
 	return rc;
 }
 EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
+
+int ata_sas_allocate_tag(struct ata_port *ap)
+{
+	unsigned int max_queue = ap->host->n_tags;
+	unsigned int 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->sas_tag_allocated)) {
+			ap->sas_last_tag = tag;
+			return tag;
+		}
+	}
+	return -1;
+}
+
+void ata_sas_free_tag(unsigned int tag, struct ata_port *ap)
+{
+	clear_bit(tag, &ap->sas_tag_allocated);
+}
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 40405135bbb6..8c491cd8805b 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -145,6 +145,8 @@ extern void ata_scsi_dev_rescan(struct work_struct *work);
 extern int ata_bus_probe(struct ata_port *ap);
 extern int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
 			      unsigned int id, u64 lun);
+int ata_sas_allocate_tag(struct ata_port *ap);
+void ata_sas_free_tag(unsigned int tag, struct ata_port *ap);
 
 
 /* libata-eh.c */