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, 2 insertions, 4 deletions

diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
index e89656bffa84..ee1605bfc29f 100644
--- a/drivers/ata/pata_platform.c
+++ b/drivers/ata/pata_platform.c
@@ -32,11 +32,9 @@ static int pio_mask = 1;
  */
 static int pata_platform_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->link.device[i];
+        struct ata_device *dev;
 
+        ata_link_for_each_dev(dev, &ap->link) {
                 if (ata_dev_enabled(dev)) {
                         /* We don't really care */
                         dev->pio_mode = dev->xfer_mode = XFER_PIO_0;