libata-sff: port_task is SFF specific

port_task is tightly bound to the standard SFF PIO HSM implementation.
Using it for any other purpose would be error-prone and there's no
such user and if some drivers need such feature, it would be much
better off using its own.  Move it inside CONFIG_ATA_SFF and rename it
to sff_pio_task.

The only function which is exposed to the core layer is
ata_sff_flush_pio_task() which is renamed from ata_port_flush_task()
and now also takes care of resetting hsm_task_state to HSM_ST_IDLE,
which is possible as it's now specific to PIO HSM.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 85b99b8..6888b5c3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -723,6 +723,7 @@
 	struct ata_ioports	ioaddr;	/* ATA cmd/ctl/dma register blocks */
 	u8			ctl;	/* cache of ATA control register */
 	u8			last_ctl;	/* Cache last written value */
+	struct delayed_work	sff_pio_task;
 #endif /* CONFIG_ATA_SFF */
 
 	unsigned int		pio_mask;
@@ -746,8 +747,6 @@
 	struct ata_host		*host;
 	struct device 		*dev;
 
-	void			*port_task_data;
-	struct delayed_work	port_task;
 	struct delayed_work	hotplug_task;
 	struct work_struct	scsi_rescan_task;
 
@@ -1031,9 +1030,6 @@
 extern int ata_cable_ignore(struct ata_port *ap);
 extern int ata_cable_unknown(struct ata_port *ap);
 
-extern void ata_pio_queue_task(struct ata_port *ap, void *data,
-			       unsigned long delay);
-
 /* Timing helpers */
 extern unsigned int ata_pio_need_iordy(const struct ata_device *);
 extern const struct ata_timing *ata_timing_find_mode(u8 xfer_mode);
@@ -1597,6 +1593,7 @@
 extern void ata_sff_irq_clear(struct ata_port *ap);
 extern int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
 			    u8 status, int in_wq);
+extern void ata_sff_queue_pio_task(struct ata_port *ap, unsigned long delay);
 extern unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc);
 extern bool ata_sff_qc_fill_rtf(struct ata_queued_cmd *qc);
 extern unsigned int ata_sff_host_intr(struct ata_port *ap,