libata-link: implement and use link/device iterators

Multiple links and different number of devices per link should be
considered to iterate over links and devices.  This patch implements
and uses link and device iterators - ata_port_for_each_link() and
ata_link_for_each_dev() - and ata_link_max_devices().

This change makes a lot of functions iterate over only possible
devices instead of from dev 0 to dev ATA_MAX_DEVICES.  All such
changes have been examined and nothing should be broken.

While at it, add a separating comment before device helpers to
distinguish them better from link helpers and others.

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

1 files changed, 5 insertions, 7 deletions

diff --git a/drivers/ata/sata_sil.c b/drivers/ata/sata_sil.c
index 2ddbe4cc71e4..4c9295a49a49 100644
--- a/drivers/ata/sata_sil.c
+++ b/drivers/ata/sata_sil.c
@@ -303,22 +303,20 @@ static int sil_set_mode (struct ata_port *ap, struct ata_device **r_failed)
 	struct ata_device *dev;
 	void __iomem *mmio_base = host->iomap[SIL_MMIO_BAR];
 	void __iomem *addr = mmio_base + sil_port[ap->port_no].xfer_mode;
-	u32 tmp, dev_mode[2];
-	unsigned int i;
+	u32 tmp, dev_mode[2] = { };
 	int rc;
 
 	rc = ata_do_set_mode(ap, r_failed);
 	if (rc)
 		return rc;
 
-	for (i = 0; i < 2; i++) {
-		dev = &ap->link.device[i];
+	ata_link_for_each_dev(dev, &ap->link) {
 		if (!ata_dev_enabled(dev))
-			dev_mode[i] = 0;	/* PIO0/1/2 */
+			dev_mode[dev->devno] = 0;	/* PIO0/1/2 */
 		else if (dev->flags & ATA_DFLAG_PIO)
-			dev_mode[i] = 1;	/* PIO3/4 */
+			dev_mode[dev->devno] = 1;	/* PIO3/4 */
 		else
-			dev_mode[i] = 3;	/* UDMA */
+			dev_mode[dev->devno] = 3;	/* UDMA */
 		/* value 2 indicates MDMA */
 	}