diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 3387fe35c54f..6420062f2c1e 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -4659,7 +4659,7 @@ static struct ata_port * ata_host_add(const struct ata_probe_ent *ent,
 
 	host->transportt = &ata_scsi_transport_template;
 
-	ap = (struct ata_port *) &host->hostdata[0];
+	ap = ata_shost_to_port(host);
 
 	ata_host_init(ap, host, host_set, ent, port_no);
 
@@ -4872,7 +4872,7 @@ void ata_host_set_remove(struct ata_host_set *host_set)
 
 int ata_scsi_release(struct Scsi_Host *host)
 {
-	struct ata_port *ap = (struct ata_port *) &host->hostdata[0];
+	struct ata_port *ap = ata_shost_to_port(host);
 	int i;
 
 	DPRINTK("ENTER\n");
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index b518654b9d60..c31b13fd5307 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -64,7 +64,7 @@
 enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 {
 	struct Scsi_Host *host = cmd->device->host;
-	struct ata_port *ap = (struct ata_port *) &host->hostdata[0];
+	struct ata_port *ap = ata_shost_to_port(host);
 	unsigned long flags;
 	struct ata_queued_cmd *qc;
 	enum scsi_eh_timer_return ret = EH_HANDLED;
@@ -99,7 +99,7 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
  */
 void ata_scsi_error(struct Scsi_Host *host)
 {
-	struct ata_port *ap = (struct ata_port *)&host->hostdata[0];
+	struct ata_port *ap = ata_shost_to_port(host);
 
 	DPRINTK("ENTER\n");
 
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 5ae7613bc157..9871f8272df0 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -395,7 +395,7 @@ void ata_dump_status(unsigned id, struct ata_taskfile *tf)
 
 int ata_scsi_device_resume(struct scsi_device *sdev)
 {
-	struct ata_port *ap = (struct ata_port *) &sdev->host->hostdata[0];
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
 	struct ata_device *dev = &ap->device[sdev->id];
 
 	return ata_device_resume(ap, dev);
@@ -403,7 +403,7 @@ int ata_scsi_device_resume(struct scsi_device *sdev)
 
 int ata_scsi_device_suspend(struct scsi_device *sdev, pm_message_t state)
 {
-	struct ata_port *ap = (struct ata_port *) &sdev->host->hostdata[0];
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
 	struct ata_device *dev = &ap->device[sdev->id];
 
 	return ata_device_suspend(ap, dev, state);
@@ -704,7 +704,7 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
 		struct ata_port *ap;
 		struct ata_device *dev;
 
-		ap = (struct ata_port *) &sdev->host->hostdata[0];
+		ap = ata_shost_to_port(sdev->host);
 		dev = &ap->device[sdev->id];
 
 		ata_scsi_dev_config(sdev, dev);
@@ -2478,7 +2478,7 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 	struct scsi_device *scsidev = cmd->device;
 	struct Scsi_Host *shost = scsidev->host;
 
-	ap = (struct ata_port *) &shost->hostdata[0];
+	ap = ata_shost_to_port(shost);
 
 	spin_unlock(shost->host_lock);
 	spin_lock(&ap->host_set->lock);
diff --git a/drivers/scsi/sata_svw.c b/drivers/scsi/sata_svw.c
index e15c693e0539..d5eb5375e265 100644
--- a/drivers/scsi/sata_svw.c
+++ b/drivers/scsi/sata_svw.c
@@ -257,7 +257,7 @@ static int k2_sata_proc_info(struct Scsi_Host *shost, char *page, char **start,
 	int len, index;
 
 	/* Find  the ata_port */
-	ap = (struct ata_port *) &shost->hostdata[0];
+	ap = ata_shost_to_port(shost);
 	if (ap == NULL)
 		return 0;
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2564bc514bca..fe0a1dcc76c2 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -33,6 +33,7 @@
 #include <asm/io.h>
 #include <linux/ata.h>
 #include <linux/workqueue.h>
+#include <scsi/scsi_host.h>
 
 /*
  * compile-time options: to be removed as soon as all the drivers are
@@ -977,4 +978,9 @@ static inline void ata_pad_free(struct ata_port *ap, struct device *dev)
 	dma_free_coherent(dev, ATA_DMA_PAD_BUF_SZ, ap->pad, ap->pad_dma);
 }
 
+static inline struct ata_port *ata_shost_to_port(struct Scsi_Host *host)
+{
+	return (struct ata_port *) &host->hostdata[0];
+}
+
 #endif /* __LINUX_LIBATA_H__ */