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, 37 insertions, 47 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 32da9a9..d673f37 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -422,7 +422,7 @@ static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
 
 	if (!dev) {
 		ehi->action &= ~action;
-		ata_link_for_each_dev(tdev, link)
+		ata_for_each_dev(tdev, link, ALL)
 			ehi->dev_action[tdev->devno] &= ~action;
 	} else {
 		/* doesn't make sense for port-wide EH actions */
@@ -430,7 +430,7 @@ static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
 
 		/* break ehi->action into ehi->dev_action */
 		if (ehi->action & action) {
-			ata_link_for_each_dev(tdev, link)
+			ata_for_each_dev(tdev, link, ALL)
 				ehi->dev_action[tdev->devno] |=
 					ehi->action & action;
 			ehi->action &= ~action;
@@ -592,7 +592,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 		/* fetch & clear EH info */
 		spin_lock_irqsave(ap->lock, flags);
 
-		__ata_port_for_each_link(link, ap) {
+		ata_for_each_link(link, ap, HOST_FIRST) {
 			struct ata_eh_context *ehc = &link->eh_context;
 			struct ata_device *dev;
 
@@ -600,12 +600,9 @@ void ata_scsi_error(struct Scsi_Host *host)
 			link->eh_context.i = link->eh_info;
 			memset(&link->eh_info, 0, sizeof(link->eh_info));
 
-			ata_link_for_each_dev(dev, link) {
+			ata_for_each_dev(dev, link, ENABLED) {
 				int devno = dev->devno;
 
-				if (!ata_dev_enabled(dev))
-					continue;
-
 				ehc->saved_xfer_mode[devno] = dev->xfer_mode;
 				if (ata_ncq_enabled(dev))
 					ehc->saved_ncq_enabled |= 1 << devno;
@@ -644,7 +641,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 		}
 
 		/* this run is complete, make sure EH info is clear */
-		__ata_port_for_each_link(link, ap)
+		ata_for_each_link(link, ap, HOST_FIRST)
 			memset(&link->eh_info, 0, sizeof(link->eh_info));
 
 		/* Clear host_eh_scheduled while holding ap->lock such
@@ -1025,7 +1022,7 @@ int sata_async_notification(struct ata_port *ap)
 		struct ata_link *link;
 
 		/* check and notify ATAPI AN */
-		ata_port_for_each_link(link, ap) {
+		ata_for_each_link(link, ap, EDGE) {
 			if (!(sntf & (1 << link->pmp)))
 				continue;
 
@@ -2005,7 +2002,7 @@ void ata_eh_autopsy(struct ata_port *ap)
 {
 	struct ata_link *link;
 
-	ata_port_for_each_link(link, ap)
+	ata_for_each_link(link, ap, EDGE)
 		ata_eh_link_autopsy(link);
 
 	/* Handle the frigging slave link.  Autopsy is done similarly
@@ -2219,7 +2216,7 @@ void ata_eh_report(struct ata_port *ap)
 {
 	struct ata_link *link;
 
-	__ata_port_for_each_link(link, ap)
+	ata_for_each_link(link, ap, HOST_FIRST)
 		ata_eh_link_report(link);
 }
 
@@ -2230,7 +2227,7 @@ static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
 	struct ata_device *dev;
 
 	if (clear_classes)
-		ata_link_for_each_dev(dev, link)
+		ata_for_each_dev(dev, link, ALL)
 			classes[dev->devno] = ATA_DEV_UNKNOWN;
 
 	return reset(link, classes, deadline);
@@ -2294,7 +2291,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 
 	ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
 
-	ata_link_for_each_dev(dev, link) {
+	ata_for_each_dev(dev, 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)
@@ -2355,7 +2352,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 						"port disabled. ignoring.\n");
 				ehc->i.action &= ~ATA_EH_RESET;
 
-				ata_link_for_each_dev(dev, link)
+				ata_for_each_dev(dev, link, ALL)
 					classes[dev->devno] = ATA_DEV_NONE;
 
 				rc = 0;
@@ -2369,7 +2366,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 		 * bang classes and return.
 		 */
 		if (reset && !(ehc->i.action & ATA_EH_RESET)) {
-			ata_link_for_each_dev(dev, link)
+			ata_for_each_dev(dev, link, ALL)
 				classes[dev->devno] = ATA_DEV_NONE;
 			rc = 0;
 			goto out;
@@ -2454,7 +2451,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	/*
 	 * Post-reset processing
 	 */
-	ata_link_for_each_dev(dev, link) {
+	ata_for_each_dev(dev, link, ALL) {
 		/* After the reset, the device state is PIO 0 and the
 		 * controller state is undefined.  Reset also wakes up
 		 * drives from sleeping mode.
@@ -2510,7 +2507,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	 * can be reliably detected and retried.
 	 */
 	nr_unknown = 0;
-	ata_link_for_each_dev(dev, link) {
+	ata_for_each_dev(dev, link, ALL) {
 		/* convert all ATA_DEV_UNKNOWN to ATA_DEV_NONE */
 		if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
 			classes[dev->devno] = ATA_DEV_NONE;
@@ -2619,8 +2616,8 @@ static inline void ata_eh_pull_park_action(struct ata_port *ap)
 
 	spin_lock_irqsave(ap->lock, flags);
 	INIT_COMPLETION(ap->park_req_pending);
-	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) {
 			struct ata_eh_info *ehi = &link->eh_info;
 
 			link->eh_context.i.dev_action[dev->devno] |=
@@ -2675,7 +2672,7 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
 	 * be done backwards such that PDIAG- is released by the slave
 	 * device before the master device is identified.
 	 */
-	ata_link_for_each_dev_reverse(dev, link) {
+	ata_for_each_dev(dev, link, ALL_REVERSE) {
 		unsigned int action = ata_eh_dev_action(dev);
 		unsigned int readid_flags = 0;
 
@@ -2744,7 +2741,7 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
 	/* Configure new devices forward such that user doesn't see
 	 * device detection messages backwards.
 	 */
-	ata_link_for_each_dev(dev, link) {
+	ata_for_each_dev(dev, link, ALL) {
 		if (!(new_mask & (1 << dev->devno)) ||
 		    dev->class == ATA_DEV_PMP)
 			continue;
@@ -2793,10 +2790,7 @@ int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
 	int rc;
 
 	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
-	ata_link_for_each_dev(dev, link) {
-		if (!ata_dev_enabled(dev))
-			continue;
-
+	ata_for_each_dev(dev, link, ENABLED) {
 		if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
 			struct ata_ering_entry *ent;
 
@@ -2813,14 +2807,11 @@ int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
 		rc = ata_do_set_mode(link, r_failed_dev);
 
 	/* if transfer mode has changed, set DUBIOUS_XFER on device */
-	ata_link_for_each_dev(dev, link) {
+	ata_for_each_dev(dev, link, ENABLED) {
 		struct ata_eh_context *ehc = &link->eh_context;
 		u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
 		u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));
 
-		if (!ata_dev_enabled(dev))
-			continue;
-
 		if (dev->xfer_mode != saved_xfer_mode ||
 		    ata_ncq_enabled(dev) != saved_ncq)
 			dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
@@ -2881,9 +2872,8 @@ static int ata_link_nr_enabled(struct ata_link *link)
 	struct ata_device *dev;
 	int cnt = 0;
 
-	ata_link_for_each_dev(dev, link)
-		if (ata_dev_enabled(dev))
-			cnt++;
+	ata_for_each_dev(dev, link, ENABLED)
+		cnt++;
 	return cnt;
 }
 
@@ -2892,7 +2882,7 @@ static int ata_link_nr_vacant(struct ata_link *link)
 	struct ata_device *dev;
 	int cnt = 0;
 
-	ata_link_for_each_dev(dev, link)
+	ata_for_each_dev(dev, link, ALL)
 		if (dev->class == ATA_DEV_UNKNOWN)
 			cnt++;
 	return cnt;
@@ -2918,7 +2908,7 @@ static int ata_eh_skip_recovery(struct ata_link *link)
 		return 0;
 
 	/* skip if class codes for all vacant slots are ATA_DEV_NONE */
-	ata_link_for_each_dev(dev, link) {
+	ata_for_each_dev(dev, link, ALL) {
 		if (dev->class == ATA_DEV_UNKNOWN &&
 		    ehc->classes[dev->devno] != ATA_DEV_NONE)
 			return 0;
@@ -3026,7 +3016,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 	DPRINTK("ENTER\n");
 
 	/* prep for recovery */
-	ata_port_for_each_link(link, ap) {
+	ata_for_each_link(link, ap, EDGE) {
 		struct ata_eh_context *ehc = &link->eh_context;
 
 		/* re-enable link? */
@@ -3038,7 +3028,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 			ata_eh_done(link, NULL, ATA_EH_ENABLE_LINK);
 		}
 
-		ata_link_for_each_dev(dev, link) {
+		ata_for_each_dev(dev, link, ALL) {
 			if (link->flags & ATA_LFLAG_NO_RETRY)
 				ehc->tries[dev->devno] = 1;
 			else
@@ -3068,19 +3058,19 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		goto out;
 
 	/* prep for EH */
-	ata_port_for_each_link(link, ap) {
+	ata_for_each_link(link, ap, EDGE) {
 		struct ata_eh_context *ehc = &link->eh_context;
 
 		/* skip EH if possible. */
 		if (ata_eh_skip_recovery(link))
 			ehc->i.action = 0;
 
-		ata_link_for_each_dev(dev, link)
+		ata_for_each_dev(dev, link, ALL)
 			ehc->classes[dev->devno] = ATA_DEV_UNKNOWN;
 	}
 
 	/* reset */
-	ata_port_for_each_link(link, ap) {
+	ata_for_each_link(link, ap, EDGE) {
 		struct ata_eh_context *ehc = &link->eh_context;
 
 		if (!(ehc->i.action & ATA_EH_RESET))
@@ -3105,8 +3095,8 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		ata_eh_pull_park_action(ap);
 
 		deadline = jiffies;
-		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) {
 				struct ata_eh_context *ehc = &link->eh_context;
 				unsigned long tmp;
 
@@ -3134,8 +3124,8 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		deadline = wait_for_completion_timeout(&ap->park_req_pending,
 						       deadline - now);
 	} while (deadline);
-	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) {
 			if (!(link->eh_context.unloaded_mask &
 			      (1 << dev->devno)))
 				continue;
@@ -3146,7 +3136,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 	}
 
 	/* the rest */
-	ata_port_for_each_link(link, ap) {
+	ata_for_each_link(link, ap, EDGE) {
 		struct ata_eh_context *ehc = &link->eh_context;
 
 		/* revalidate existing devices and attach new ones */
@@ -3172,7 +3162,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		 * disrupting the current users of the device.
 		 */
 		if (ehc->i.flags & ATA_EHI_DID_RESET) {
-			ata_link_for_each_dev(dev, link) {
+			ata_for_each_dev(dev, link, ALL) {
 				if (dev->class != ATA_DEV_ATAPI)
 					continue;
 				rc = atapi_eh_clear_ua(dev);
@@ -3183,7 +3173,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 
 		/* configure link power saving */
 		if (ehc->i.action & ATA_EH_LPM)
-			ata_link_for_each_dev(dev, link)
+			ata_for_each_dev(dev, link, ALL)
 				ata_dev_enable_pm(dev, ap->pm_policy);
 
 		/* this link is okay now */
@@ -3288,7 +3278,7 @@ void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
 	rc = ata_eh_recover(ap, prereset, softreset, hardreset, postreset,
 			    NULL);
 	if (rc) {
-		ata_link_for_each_dev(dev, &ap->link)
+		ata_for_each_dev(dev, &ap->link, ALL)
 			ata_dev_disable(dev);
 	}