libata: beef up iterators

There currently are the following looping constructs.

* __ata_port_for_each_link() for all available links
* ata_port_for_each_link() for edge links
* ata_link_for_each_dev() for all devices
* ata_link_for_each_dev_reverse() for all devices in reverse order

Now there's a need for looping construct which is similar to
__ata_port_for_each_link() but iterates over PMP links before the host
link.  Instead of adding another one with long name, do the following
cleanup.

* Implement and export ata_link_next() and ata_dev_next() which take
  @mode parameter and can be used to build custom loop.
* Implement ata_for_each_link() and ata_for_each_dev() which take
  looping mode explicitly.

The following iteration modes are implemented.

* ATA_LITER_EDGE		: loop over edge links
* ATA_LITER_HOST_FIRST		: loop over all links, host link first
* ATA_LITER_PMP_FIRST		: loop over all links, PMP links first

* ATA_DITER_ENABLED		: loop over enabled devices
* ATA_DITER_ENABLED_REVERSE	: loop over enabled devices in reverse order
* ATA_DITER_ALL			: loop over all devices
* ATA_DITER_ALL_REVERSE		: loop over all devices in reverse order

This change removes exlicit device enabledness checks from many loops
and makes it clear which ones are iterated over in which direction.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 11 insertions, 11 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 47c7afcb36f2..0b2e14f67655 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3229,12 +3229,12 @@ void ata_scsi_scan_host(struct ata_port *ap, int sync)
                 return;
 
  repeat:
-        ata_port_for_each_link(link, ap) {
-                ata_link_for_each_dev(dev, link) {
+        ata_for_each_link(link, ap, EDGE) {
+                ata_for_each_dev(dev, link, ENABLED) {
                         struct scsi_device *sdev;
                         int channel = 0, id = 0;
 
-                        if (!ata_dev_enabled(dev) || dev->sdev)
+                        if (dev->sdev)
                                 continue;
 
                         if (ata_is_host_link(link))
@@ -3255,9 +3255,9 @@ void ata_scsi_scan_host(struct ata_port *ap, int sync)
          * failure occurred, scan would have failed silently.  Check
          * whether all devices are attached.
          */
-        ata_port_for_each_link(link, ap) {
-                ata_link_for_each_dev(dev, link) {
-                        if (ata_dev_enabled(dev) && !dev->sdev)
+        ata_for_each_link(link, ap, EDGE) {
+                ata_for_each_dev(dev, link, ENABLED) {
+                        if (!dev->sdev)
                                 goto exit_loop;
                 }
         }
@@ -3381,7 +3381,7 @@ static void ata_scsi_handle_link_detach(struct ata_link *link)
         struct ata_port *ap = link->ap;
         struct ata_device *dev;
 
-        ata_link_for_each_dev(dev, link) {
+        ata_for_each_dev(dev, link, ALL) {
                 unsigned long flags;
 
                 if (!(dev->flags & ATA_DFLAG_DETACHED))
@@ -3496,7 +3496,7 @@ static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
         if (devno == SCAN_WILD_CARD) {
                 struct ata_link *link;
 
-                ata_port_for_each_link(link, ap) {
+                ata_for_each_link(link, ap, EDGE) {
                         struct ata_eh_info *ehi = &link->eh_info;
                         ehi->probe_mask |= ATA_ALL_DEVICES;
                         ehi->action |= ATA_EH_RESET;
@@ -3544,11 +3544,11 @@ void ata_scsi_dev_rescan(struct work_struct *work)
 
         spin_lock_irqsave(ap->lock, flags);
 
-        ata_port_for_each_link(link, ap) {
-                ata_link_for_each_dev(dev, link) {
+        ata_for_each_link(link, ap, EDGE) {
+                ata_for_each_dev(dev, link, ENABLED) {
                         struct scsi_device *sdev = dev->sdev;
 
-                        if (!ata_dev_enabled(dev) || !sdev)
+                        if (!sdev)
                                 continue;
                         if (scsi_device_get(sdev))
                                 continue;