libata-link: introduce ata_link

Introduce ata_link.  It abstracts PHY and sits between ata_port and
ata_device.  This new level of abstraction is necessary to support
SATA Port Multiplier, which basically adds a bunch of links (PHYs) to
a ATA host port.  Fields related to command execution, spd_limit and
EH are per-link and thus moved to ata_link.

This patch only defines the host link.  Multiple link handling will be
added later.  Also, a lot of ap->link derefences are added but many of
them will be removed as each part is converted to deal directly with
ata_link instead of ata_port.

This patch introduces no behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/ata/pata_legacy.c b/drivers/ata/pata_legacy.c
index edffc25d2d3f..4bcc0ae8d108 100644
--- a/drivers/ata/pata_legacy.c
+++ b/drivers/ata/pata_legacy.c
@@ -112,7 +112,7 @@ static int legacy_set_mode(struct ata_port *ap, struct ata_device **unused)
         int i;
 
         for (i = 0; i < ATA_MAX_DEVICES; i++) {
-                struct ata_device *dev = &ap->device[i];
+                struct ata_device *dev = &ap->link.device[i];
                 if (ata_dev_enabled(dev)) {
                         ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
                         dev->pio_mode = XFER_PIO_0;
@@ -256,7 +256,7 @@ static void pdc20230_set_piomode(struct ata_port *ap, struct ata_device *adev)
 
 static void pdc_data_xfer_vlb(struct ata_device *adev, unsigned char *buf, unsigned int buflen, int write_data)
 {
-        struct ata_port *ap = adev->ap;
+        struct ata_port *ap = adev->link->ap;
         int slop = buflen & 3;
         unsigned long flags;