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/sata_sx4.c b/drivers/ata/sata_sx4.c
index 97aefdd87be4..12691f091933 100644
--- a/drivers/ata/sata_sx4.c
+++ b/drivers/ata/sata_sx4.c
@@ -854,7 +854,7 @@ static irqreturn_t pdc20621_interrupt (int irq, void *dev_instance)
                     !(ap->flags & ATA_FLAG_DISABLED)) {
                         struct ata_queued_cmd *qc;
 
-                        qc = ata_qc_from_tag(ap, ap->active_tag);
+                        qc = ata_qc_from_tag(ap, ap->link.active_tag);
                         if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)))
                                 handled += pdc20621_host_intr(ap, qc, (i > 4),
                                                               mmio_base);
@@ -881,7 +881,7 @@ static void pdc_eng_timeout(struct ata_port *ap)
 
         spin_lock_irqsave(&host->lock, flags);
 
-        qc = ata_qc_from_tag(ap, ap->active_tag);
+        qc = ata_qc_from_tag(ap, ap->link.active_tag);
 
         switch (qc->tf.protocol) {
         case ATA_PROT_DMA: