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>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index bc6695e..ffd98e4 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -163,43 +163,119 @@
MODULE_VERSION(DRV_VERSION);
-/*
- * Iterator helpers. Don't use directly.
+/**
+ * ata_link_next - link iteration helper
+ * @link: the previous link, NULL to start
+ * @ap: ATA port containing links to iterate
+ * @mode: iteration mode, one of ATA_LITER_*
*
- * LOCKING:
- * Host lock or EH context.
+ * LOCKING:
+ * Host lock or EH context.
+ *
+ * RETURNS:
+ * Pointer to the next link.
*/
-struct ata_link *__ata_port_next_link(struct ata_port *ap,
- struct ata_link *link, bool dev_only)
+struct ata_link *ata_link_next(struct ata_link *link, struct ata_port *ap,
+ enum ata_link_iter_mode mode)
{
- /* NULL link indicates start of iteration */
- if (!link) {
- if (dev_only && sata_pmp_attached(ap))
- return ap->pmp_link;
- return &ap->link;
- }
+ BUG_ON(mode != ATA_LITER_EDGE &&
+ mode != ATA_LITER_PMP_FIRST && mode != ATA_LITER_HOST_FIRST);
- /* we just iterated over the host master link, what's next? */
- if (link == &ap->link) {
- if (!sata_pmp_attached(ap)) {
- if (unlikely(ap->slave_link) && !dev_only)
+ /* NULL link indicates start of iteration */
+ if (!link)
+ switch (mode) {
+ case ATA_LITER_EDGE:
+ case ATA_LITER_PMP_FIRST:
+ if (sata_pmp_attached(ap))
+ return ap->pmp_link;
+ /* fall through */
+ case ATA_LITER_HOST_FIRST:
+ return &ap->link;
+ }
+
+ /* we just iterated over the host link, what's next? */
+ if (link == &ap->link)
+ switch (mode) {
+ case ATA_LITER_HOST_FIRST:
+ if (sata_pmp_attached(ap))
+ return ap->pmp_link;
+ /* fall through */
+ case ATA_LITER_PMP_FIRST:
+ if (unlikely(ap->slave_link))
return ap->slave_link;
+ /* fall through */
+ case ATA_LITER_EDGE:
return NULL;
}
- return ap->pmp_link;
- }
/* slave_link excludes PMP */
if (unlikely(link == ap->slave_link))
return NULL;
- /* iterate to the next PMP link */
+ /* we were over a PMP link */
if (++link < ap->pmp_link + ap->nr_pmp_links)
return link;
+
+ if (mode == ATA_LITER_PMP_FIRST)
+ return &ap->link;
+
return NULL;
}
/**
+ * ata_dev_next - device iteration helper
+ * @dev: the previous device, NULL to start
+ * @link: ATA link containing devices to iterate
+ * @mode: iteration mode, one of ATA_DITER_*
+ *
+ * LOCKING:
+ * Host lock or EH context.
+ *
+ * RETURNS:
+ * Pointer to the next device.
+ */
+struct ata_device *ata_dev_next(struct ata_device *dev, struct ata_link *link,
+ enum ata_dev_iter_mode mode)
+{
+ BUG_ON(mode != ATA_DITER_ENABLED && mode != ATA_DITER_ENABLED_REVERSE &&
+ mode != ATA_DITER_ALL && mode != ATA_DITER_ALL_REVERSE);
+
+ /* NULL dev indicates start of iteration */
+ if (!dev)
+ switch (mode) {
+ case ATA_DITER_ENABLED:
+ case ATA_DITER_ALL:
+ dev = link->device;
+ goto check;
+ case ATA_DITER_ENABLED_REVERSE:
+ case ATA_DITER_ALL_REVERSE:
+ dev = link->device + ata_link_max_devices(link) - 1;
+ goto check;
+ }
+
+ next:
+ /* move to the next one */
+ switch (mode) {
+ case ATA_DITER_ENABLED:
+ case ATA_DITER_ALL:
+ if (++dev < link->device + ata_link_max_devices(link))
+ goto check;
+ return NULL;
+ case ATA_DITER_ENABLED_REVERSE:
+ case ATA_DITER_ALL_REVERSE:
+ if (--dev >= link->device)
+ goto check;
+ return NULL;
+ }
+
+ check:
+ if ((mode == ATA_DITER_ENABLED || mode == ATA_DITER_ENABLED_REVERSE) &&
+ !ata_dev_enabled(dev))
+ goto next;
+ return dev;
+}
+
+/**
* ata_dev_phys_link - find physical link for a device
* @dev: ATA device to look up physical link for
*
@@ -1107,8 +1183,8 @@
for (i = 0; i < host->n_ports; i++) {
ap = host->ports[i];
- 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, ALL)
ata_dev_disable_pm(dev);
}
}
@@ -2594,11 +2670,11 @@
ata_port_probe(ap);
- ata_link_for_each_dev(dev, &ap->link)
+ ata_for_each_dev(dev, &ap->link, ALL)
tries[dev->devno] = ATA_PROBE_MAX_TRIES;
retry:
- ata_link_for_each_dev(dev, &ap->link) {
+ ata_for_each_dev(dev, &ap->link, ALL) {
/* If we issue an SRST then an ATA drive (not ATAPI)
* may change configuration and be in PIO0 timing. If
* we do a hard reset (or are coming from power on)
@@ -2620,7 +2696,7 @@
/* reset and determine device classes */
ap->ops->phy_reset(ap);
- ata_link_for_each_dev(dev, &ap->link) {
+ ata_for_each_dev(dev, &ap->link, ALL) {
if (!(ap->flags & ATA_FLAG_DISABLED) &&
dev->class != ATA_DEV_UNKNOWN)
classes[dev->devno] = dev->class;
@@ -2636,7 +2712,7 @@
specific sequence bass-ackwards so that PDIAG- is released by
the slave device */
- ata_link_for_each_dev_reverse(dev, &ap->link) {
+ ata_for_each_dev(dev, &ap->link, ALL_REVERSE) {
if (tries[dev->devno])
dev->class = classes[dev->devno];
@@ -2653,24 +2729,19 @@
if (ap->ops->cable_detect)
ap->cbl = ap->ops->cable_detect(ap);
- /* We may have SATA bridge glue hiding here irrespective of the
- reported cable types and sensed types */
- ata_link_for_each_dev(dev, &ap->link) {
- if (!ata_dev_enabled(dev))
- continue;
- /* SATA drives indicate we have a bridge. We don't know which
- end of the link the bridge is which is a problem */
+ /* We may have SATA bridge glue hiding here irrespective of
+ * the reported cable types and sensed types. When SATA
+ * drives indicate we have a bridge, we don't know which end
+ * of the link the bridge is which is a problem.
+ */
+ ata_for_each_dev(dev, &ap->link, ENABLED)
if (ata_id_is_sata(dev->id))
ap->cbl = ATA_CBL_SATA;
- }
/* After the identify sequence we can now set up the devices. We do
this in the normal order so that the user doesn't get confused */
- ata_link_for_each_dev(dev, &ap->link) {
- if (!ata_dev_enabled(dev))
- continue;
-
+ ata_for_each_dev(dev, &ap->link, ENABLED) {
ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
rc = ata_dev_configure(dev);
ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
@@ -2683,9 +2754,8 @@
if (rc)
goto fail;
- ata_link_for_each_dev(dev, &ap->link)
- if (ata_dev_enabled(dev))
- return 0;
+ ata_for_each_dev(dev, &ap->link, ENABLED)
+ return 0;
/* no device present, disable port */
ata_port_disable(ap);
@@ -3331,13 +3401,10 @@
int rc = 0, used_dma = 0, found = 0;
/* step 1: calculate xfer_mask */
- ata_link_for_each_dev(dev, link) {
+ ata_for_each_dev(dev, link, ENABLED) {
unsigned long pio_mask, dma_mask;
unsigned int mode_mask;
- if (!ata_dev_enabled(dev))
- continue;
-
mode_mask = ATA_DMA_MASK_ATA;
if (dev->class == ATA_DEV_ATAPI)
mode_mask = ATA_DMA_MASK_ATAPI;
@@ -3366,10 +3433,7 @@
goto out;
/* step 2: always set host PIO timings */
- ata_link_for_each_dev(dev, link) {
- if (!ata_dev_enabled(dev))
- continue;
-
+ ata_for_each_dev(dev, link, ENABLED) {
if (dev->pio_mode == 0xff) {
ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
rc = -EINVAL;
@@ -3383,8 +3447,8 @@
}
/* step 3: set host DMA timings */
- ata_link_for_each_dev(dev, link) {
- if (!ata_dev_enabled(dev) || !ata_dma_enabled(dev))
+ ata_for_each_dev(dev, link, ENABLED) {
+ if (!ata_dma_enabled(dev))
continue;
dev->xfer_mode = dev->dma_mode;
@@ -3394,11 +3458,7 @@
}
/* step 4: update devices' xfer mode */
- ata_link_for_each_dev(dev, link) {
- /* don't update suspended devices' xfer mode */
- if (!ata_dev_enabled(dev))
- continue;
-
+ ata_for_each_dev(dev, link, ENABLED) {
rc = ata_dev_set_mode(dev);
if (rc)
goto out;
@@ -4263,9 +4323,9 @@
* - if you have a non detect capable drive you don't want it
* to colour the choice
*/
- ata_port_for_each_link(link, ap) {
- ata_link_for_each_dev(dev, link) {
- if (ata_dev_enabled(dev) && !ata_is_40wire(dev))
+ ata_for_each_link(link, ap, EDGE) {
+ ata_for_each_dev(dev, link, ENABLED) {
+ if (!ata_is_40wire(dev))
return 0;
}
}
@@ -5218,7 +5278,7 @@
}
ap->pflags |= ATA_PFLAG_PM_PENDING;
- __ata_port_for_each_link(link, ap) {
+ ata_for_each_link(link, ap, HOST_FIRST) {
link->eh_info.action |= action;
link->eh_info.flags |= ehi_flags;
}
@@ -6063,9 +6123,9 @@
/* EH is now guaranteed to see UNLOADING - EH context belongs
* to us. Restore SControl and disable all existing devices.
*/
- __ata_port_for_each_link(link, ap) {
+ ata_for_each_link(link, ap, HOST_FIRST) {
sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
- ata_link_for_each_dev(dev, link)
+ ata_for_each_dev(dev, link, ALL)
ata_dev_disable(dev);
}
@@ -6528,7 +6588,8 @@
EXPORT_SYMBOL_GPL(sata_port_ops);
EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
EXPORT_SYMBOL_GPL(ata_dummy_port_info);
-EXPORT_SYMBOL_GPL(__ata_port_next_link);
+EXPORT_SYMBOL_GPL(ata_link_next);
+EXPORT_SYMBOL_GPL(ata_dev_next);
EXPORT_SYMBOL_GPL(ata_std_bios_param);
EXPORT_SYMBOL_GPL(ata_host_init);
EXPORT_SYMBOL_GPL(ata_host_alloc);