libata: make SCR access ops per-link

Logically, SCR access ops should take @link; however, there was no
compelling reason to convert all SCR access ops when adding @link
abstraction as there's one-to-one mapping between a port and a non-PMP
link.  However, that assumption won't hold anymore with the scheduled
addition of slave link.

Make SCR access ops per-link.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/sata_qstor.c b/drivers/ata/sata_qstor.c
index 1600107..a000c86 100644
--- a/drivers/ata/sata_qstor.c
+++ b/drivers/ata/sata_qstor.c
@@ -111,8 +111,8 @@
 	qs_state_t		state;
 };
 
-static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int qs_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int qs_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int qs_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static int qs_ata_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 static int qs_port_start(struct ata_port *ap);
 static void qs_host_stop(struct ata_host *host);
@@ -242,11 +242,11 @@
 	return ata_sff_prereset(link, deadline);
 }
 
-static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int qs_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	*val = readl(ap->ioaddr.scr_addr + (sc_reg * 8));
+	*val = readl(link->ap->ioaddr.scr_addr + (sc_reg * 8));
 	return 0;
 }
 
@@ -256,11 +256,11 @@
 	ata_std_error_handler(ap);
 }
 
-static int qs_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int qs_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	writel(val, ap->ioaddr.scr_addr + (sc_reg * 8));
+	writel(val, link->ap->ioaddr.scr_addr + (sc_reg * 8));
 	return 0;
 }