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libata: beef up iterators

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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>
This commit is contained in:
Tejun Heo
2008-11-03 20:03:17 +09:00
committed by Jeff Garzik
parent 3c92ec8ae9
commit 1eca4365be
15 changed files with 302 additions and 235 deletions
Download Patch File Download Diff File Expand all files Collapse all files

185
drivers/ata/libata-core.c
View File

@@ -163,42 +163,118 @@ MODULE_LICENSE("GPL");
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 @@ static void ata_lpm_enable(struct ata_host *host)
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 @@ int ata_bus_probe(struct ata_port *ap)
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 @@ int ata_bus_probe(struct ata_port *ap)
/* 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 @@ int ata_bus_probe(struct ata_port *ap)
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 @@ int ata_bus_probe(struct ata_port *ap)
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 @@ int ata_bus_probe(struct ata_port *ap)
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 ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
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 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
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 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
}
/* 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 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
}
/* 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 @@ static int cable_is_40wire(struct ata_port *ap)
* - 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 @@ static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
}
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 @@ static void ata_port_detach(struct ata_port *ap)
/* 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(ata_base_port_ops);
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);