[PATCH #upstream-fixes 1/4] libata: fix device iteration bugs

[PATCH #upstream-fixes 1/4] libata: fix device iteration bugs

[Tejun Heo]

There were several places where only enabled devices should be
iterated over but device enabledness wasn't checked.

* IDENTIFY data 40 wire check in cable_is_40wire()
* xfer_mode/ncq_enabled saving in ata_scsi_error()
* DUBIOUS_XFER handling in ata_set_mode()

While at it, reformat comment in cable_is_40wire().

Signed-off-by: Tejun Heo <tj@kernel.org>
---
Jeff, this four patch series fixes iteration bugs and improves
iterators and fix ata_port_detach() related bugs.  The iterator change
is a bit big for #upstream-fixes but it's fairly straight forward and
I verified them in most combinations, so it should be pretty safe.

Thanks.

 drivers/ata/libata-core.c |   18 ++++++++----------
 drivers/ata/libata-eh.c   |    9 +++++++++
 2 files changed, 17 insertions(+), 10 deletions(-)

Index: work/drivers/ata/libata-core.c
===================================================================
--- work.orig/drivers/ata/libata-core.c
+++ work/drivers/ata/libata-core.c
@@ -4169,18 +4169,16 @@ static int cable_is_40wire(struct ata_po
 	if (ap->cbl == ATA_CBL_PATA40_SHORT)
 		return 0;
 	/* If the controller doesn't know we scan
-
-	   - Note: We look for all 40 wire detects at this point.
-	     Any 80 wire detect is taken to be 80 wire cable
-	     because
-	     - In many setups only the one drive (slave if present)
-               will give a valid detect
-             - If you have a non detect capable drive you don't
-               want it to colour the choice
-        */
+	 *
+	 * - Note: We look for all 40 wire detects at this point.  Any
+	 *   80 wire detect is taken to be 80 wire cable because - In
+	 *   many setups only the one drive (slave if present) will
+	 *   give a valid detect - 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_is_40wire(dev))
+			if (ata_dev_enabled(dev) && !ata_is_40wire(dev))
 				return 0;
 		}
 	}
Index: work/drivers/ata/libata-eh.c
===================================================================
--- work.orig/drivers/ata/libata-eh.c
+++ work/drivers/ata/libata-eh.c
@@ -603,6 +603,9 @@ void ata_scsi_error(struct Scsi_Host *ho
 			ata_link_for_each_dev(dev, link) {
 				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;
@@ -2790,6 +2793,9 @@ int ata_set_mode(struct ata_link *link,
 
 	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
 	ata_link_for_each_dev(dev, link) {
+		if (!ata_dev_enabled(dev))
+			continue;
+
 		if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
 			struct ata_ering_entry *ent;
 
@@ -2811,6 +2817,9 @@ int ata_set_mode(struct ata_link *link,
 		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;

[PATCH #upstream-fixes 2/4] libata: beef up iterators

[Tejun Heo]

There currently are the following loop 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 loop 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>
---
 drivers/ata/ahci.c           |    8 -
 drivers/ata/ata_generic.c    |    5 -
 drivers/ata/libata-acpi.c    |   19 +---
 drivers/ata/libata-core.c    |  183 ++++++++++++++++++++++++++++---------------
 drivers/ata/libata-eh.c      |   84 ++++++++-----------
 drivers/ata/libata-pmp.c     |   22 ++---
 drivers/ata/libata-scsi.c    |   22 ++---
 drivers/ata/pata_it821x.c    |   34 +++----
 drivers/ata/pata_ixp4xx_cf.c |   14 +--
 drivers/ata/pata_legacy.c    |   17 +--
 drivers/ata/pata_pdc2027x.c  |   27 ++----
 drivers/ata/pata_platform.c  |   14 +--
 drivers/ata/pata_rz1000.c    |   16 +--
 drivers/ata/sata_sil.c       |    2 
 include/linux/libata.h       |   50 +++++++----
 15 files changed, 279 insertions(+), 238 deletions(-)

Index: work/drivers/ata/libata-core.c
===================================================================
--- work.orig/drivers/ata/libata-core.c
+++ work/drivers/ata/libata-core.c
@@ -163,43 +163,119 @@ 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)
 {
+	BUG_ON(mode != ATA_LITER_EDGE &&
+	       mode != ATA_LITER_PMP_FIRST && mode != ATA_LITER_HOST_FIRST);
+
 	/* NULL link indicates start of iteration */
-	if (!link) {
-		if (dev_only && sata_pmp_attached(ap))
-			return ap->pmp_link;
-		return &ap->link;
-	}
+	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 master link, what's next? */
-	if (link == &ap->link) {
-		if (!sata_pmp_attached(ap)) {
-			if (unlikely(ap->slave_link) && !dev_only)
+	/* 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_ho
 
 	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);
 		}
 	}
@@ -2584,11 +2660,11 @@ 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)
@@ -2610,7 +2686,7 @@ 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;
@@ -2626,7 +2702,7 @@ 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];
 
@@ -2643,24 +2719,19 @@ 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;
@@ -2673,9 +2744,8 @@ 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);
@@ -3321,13 +3391,10 @@ int ata_do_set_mode(struct ata_link *lin
 	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;
@@ -3356,10 +3423,7 @@ int ata_do_set_mode(struct ata_link *lin
 		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;
@@ -3373,8 +3437,8 @@ int ata_do_set_mode(struct ata_link *lin
 	}
 
 	/* 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;
@@ -3384,11 +3448,7 @@ int ata_do_set_mode(struct ata_link *lin
 	}
 
 	/* 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;
@@ -4176,9 +4236,9 @@ static int cable_is_40wire(struct ata_po
 	 *   give a valid detect - 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;
 		}
 	}
@@ -5130,7 +5190,7 @@ static int ata_host_request_pm(struct at
 		}
 
 		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;
 		}
@@ -5975,9 +6035,9 @@ static void ata_port_detach(struct ata_p
 	/* 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);
-		ata_link_for_each_dev(dev, link)
+		ata_for_each_dev(dev, link, ALL)
 			ata_dev_disable(dev);
 	}
 
@@ -6440,7 +6500,8 @@ 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);
Index: work/drivers/ata/libata-eh.c
===================================================================
--- work.orig/drivers/ata/libata-eh.c
+++ work/drivers/ata/libata-eh.c
@@ -422,7 +422,7 @@ static void ata_eh_clear_action(struct a
 
 	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 a
 
 		/* 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 *ho
 		/* 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 *ho
 			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;
@@ -647,7 +644,7 @@ void ata_scsi_error(struct Scsi_Host *ho
 		}
 
 		/* 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
@@ -1028,7 +1025,7 @@ int sata_async_notification(struct ata_p
 		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;
 
@@ -2008,7 +2005,7 @@ 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
@@ -2222,7 +2219,7 @@ 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);
 }
 
@@ -2233,7 +2230,7 @@ static int ata_do_reset(struct ata_link
 	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);
@@ -2293,7 +2290,7 @@ int ata_eh_reset(struct ata_link *link,
 	ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
 	ehc->last_reset = jiffies;
 
-	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)
@@ -2354,7 +2351,7 @@ int ata_eh_reset(struct ata_link *link,
 						"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;
@@ -2368,7 +2365,7 @@ int ata_eh_reset(struct ata_link *link,
 		 * 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;
@@ -2453,7 +2450,7 @@ int ata_eh_reset(struct ata_link *link,
 	/*
 	 * 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.
@@ -2509,7 +2506,7 @@ int ata_eh_reset(struct ata_link *link,
 	 * 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;
@@ -2618,8 +2615,8 @@ static inline void ata_eh_pull_park_acti
 
 	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] |=
@@ -2674,7 +2671,7 @@ static int ata_eh_revalidate_and_attach(
 	 * 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;
 
@@ -2743,7 +2740,7 @@ static int ata_eh_revalidate_and_attach(
 	/* 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;
@@ -2792,10 +2789,7 @@ int ata_set_mode(struct ata_link *link,
 	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;
 
@@ -2812,14 +2806,11 @@ int ata_set_mode(struct ata_link *link,
 		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;
@@ -2880,9 +2871,8 @@ static int ata_link_nr_enabled(struct at
 	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;
 }
 
@@ -2891,7 +2881,7 @@ static int ata_link_nr_vacant(struct ata
 	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;
@@ -2917,7 +2907,7 @@ static int ata_eh_skip_recovery(struct a
 		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;
@@ -3025,7 +3015,7 @@ int ata_eh_recover(struct ata_port *ap,
 	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? */
@@ -3037,7 +3027,7 @@ int ata_eh_recover(struct ata_port *ap,
 			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
@@ -3067,19 +3057,19 @@ int ata_eh_recover(struct ata_port *ap,
 		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))
@@ -3104,8 +3094,8 @@ int ata_eh_recover(struct ata_port *ap,
 		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;
 
@@ -3133,8 +3123,8 @@ int ata_eh_recover(struct ata_port *ap,
 		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;
@@ -3145,7 +3135,7 @@ int ata_eh_recover(struct ata_port *ap,
 	}
 
 	/* 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 */
@@ -3171,7 +3161,7 @@ int ata_eh_recover(struct ata_port *ap,
 		 * 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);
@@ -3182,7 +3172,7 @@ int ata_eh_recover(struct ata_port *ap,
 
 		/* 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 */
@@ -3287,7 +3277,7 @@ void ata_do_eh(struct ata_port *ap, ata_
 	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);
 	}
 
Index: work/include/linux/libata.h
===================================================================
--- work.orig/include/linux/libata.h
+++ work/include/linux/libata.h
@@ -1281,26 +1281,36 @@ static inline int ata_link_active(struct
 	return ata_tag_valid(link->active_tag) || link->sactive;
 }
 
-extern struct ata_link *__ata_port_next_link(struct ata_port *ap,
-					     struct ata_link *link,
-					     bool dev_only);
-
-#define __ata_port_for_each_link(link, ap) \
-	for ((link) = __ata_port_next_link((ap), NULL, false); (link); \
-	     (link) = __ata_port_next_link((ap), (link), false))
-
-#define ata_port_for_each_link(link, ap) \
-	for ((link) = __ata_port_next_link((ap), NULL, true); (link); \
-	     (link) = __ata_port_next_link((ap), (link), true))
-
-#define ata_link_for_each_dev(dev, link) \
-	for ((dev) = (link)->device; \
-	     (dev) < (link)->device + ata_link_max_devices(link) || ((dev) = NULL); \
-	     (dev)++)
-
-#define ata_link_for_each_dev_reverse(dev, link) \
-	for ((dev) = (link)->device + ata_link_max_devices(link) - 1; \
-	     (dev) >= (link)->device || ((dev) = NULL); (dev)--)
+enum ata_link_iter_mode {
+	ATA_LITER_EDGE,		/* if present, PMP links only; otherwise,
+				 * host link.  no slave link */
+	ATA_LITER_HOST_FIRST,	/* host link followed by PMP or slave links */
+	ATA_LITER_PMP_FIRST,	/* PMP links followed by host link,
+				 * slave link still comes after host link */
+};
+
+enum ata_dev_iter_mode {
+	ATA_DITER_ENABLED,
+	ATA_DITER_ENABLED_REVERSE,
+	ATA_DITER_ALL,
+	ATA_DITER_ALL_REVERSE,
+};
+
+extern struct ata_link *ata_link_next(struct ata_link *link,
+				      struct ata_port *ap,
+				      enum ata_link_iter_mode mode);
+
+extern struct ata_device *ata_dev_next(struct ata_device *dev,
+				       struct ata_link *link,
+				       enum ata_dev_iter_mode mode);
+
+#define ata_for_each_link(link, ap, mode) \
+	for ((link) = ata_link_next(NULL, (ap), ATA_LITER_##mode); (link); \
+	     (link) = ata_link_next((link), (ap), ATA_LITER_##mode))
+
+#define ata_for_each_dev(dev, link, mode) \
+	for ((dev) = ata_dev_next(NULL, (link), ATA_DITER_##mode); (dev); \
+	     (dev) = ata_dev_next((dev), (link), ATA_DITER_##mode))
 
 /**
  *	ata_ncq_enabled - Test whether NCQ is enabled
Index: work/drivers/ata/ahci.c
===================================================================
--- work.orig/drivers/ata/ahci.c
+++ work/drivers/ata/ahci.c
@@ -1105,14 +1105,14 @@ static void ahci_start_port(struct ata_p
 
 	/* turn on LEDs */
 	if (ap->flags & ATA_FLAG_EM) {
-		ata_port_for_each_link(link, ap) {
+		ata_for_each_link(link, ap, EDGE) {
 			emp = &pp->em_priv[link->pmp];
 			ahci_transmit_led_message(ap, emp->led_state, 4);
 		}
 	}
 
 	if (ap->flags & ATA_FLAG_SW_ACTIVITY)
-		ata_port_for_each_link(link, ap)
+		ata_for_each_link(link, ap, EDGE)
 			ahci_init_sw_activity(link);
 
 }
@@ -1344,7 +1344,7 @@ static ssize_t ahci_led_show(struct ata_
 	struct ahci_em_priv *emp;
 	int rc = 0;
 
-	ata_port_for_each_link(link, ap) {
+	ata_for_each_link(link, ap, EDGE) {
 		emp = &pp->em_priv[link->pmp];
 		rc += sprintf(buf, "%lx\n", emp->led_state);
 	}
@@ -1924,7 +1924,7 @@ static void ahci_error_intr(struct ata_p
 	u32 serror;
 
 	/* determine active link */
-	ata_port_for_each_link(link, ap)
+	ata_for_each_link(link, ap, EDGE)
 		if (ata_link_active(link))
 			break;
 	if (!link)
Index: work/drivers/ata/ata_generic.c
===================================================================
--- work.orig/drivers/ata/ata_generic.c
+++ work/drivers/ata/ata_generic.c
@@ -57,10 +57,7 @@ static int generic_set_mode(struct ata_l
 	if (pdev->vendor == PCI_VENDOR_ID_CENATEK)
 		dma_enabled = 0xFF;
 
-	ata_link_for_each_dev(dev, link) {
-		if (!ata_dev_enabled(dev))
-			continue;
-
+	ata_for_each_dev(dev, link, ENABLED) {
 		/* We don't really care */
 		dev->pio_mode = XFER_PIO_0;
 		dev->dma_mode = XFER_MW_DMA_0;
Index: work/drivers/ata/libata-acpi.c
===================================================================
--- work.orig/drivers/ata/libata-acpi.c
+++ work/drivers/ata/libata-acpi.c
@@ -89,7 +89,7 @@ void ata_acpi_associate_sata_port(struct
 
 		ap->link.device->acpi_handle = NULL;
 
-		ata_port_for_each_link(link, ap) {
+		ata_for_each_link(link, ap, EDGE) {
 			acpi_integer adr = SATA_ADR(ap->port_no, link->pmp);
 
 			link->device->acpi_handle =
@@ -144,8 +144,8 @@ static void ata_acpi_detach_device(struc
 		struct ata_link *tlink;
 		struct ata_device *tdev;
 
-		ata_port_for_each_link(tlink, ap)
-			ata_link_for_each_dev(tdev, tlink)
+		ata_for_each_link(tlink, ap, EDGE)
+			ata_for_each_dev(tdev, tlink, ALL)
 				tdev->flags |= ATA_DFLAG_DETACH;
 	}
 
@@ -627,12 +627,9 @@ int ata_acpi_cbl_80wire(struct ata_port
 {
 	struct ata_device *dev;
 
-	ata_link_for_each_dev(dev, &ap->link) {
+	ata_for_each_dev(dev, &ap->link, ENABLED) {
 		unsigned long xfer_mask, udma_mask;
 
-		if (!ata_dev_enabled(dev))
-			continue;
-
 		xfer_mask = ata_acpi_gtm_xfermask(dev, gtm);
 		ata_unpack_xfermask(xfer_mask, NULL, NULL, &udma_mask);
 
@@ -932,7 +929,7 @@ void ata_acpi_on_resume(struct ata_port
 		 * use values set by _STM.  Cache _GTF result and
 		 * schedule _GTF.
 		 */
-		ata_link_for_each_dev(dev, &ap->link) {
+		ata_for_each_dev(dev, &ap->link, ALL) {
 			ata_acpi_clear_gtf(dev);
 			if (ata_dev_enabled(dev) &&
 			    ata_dev_get_GTF(dev, NULL) >= 0)
@@ -943,7 +940,7 @@ void ata_acpi_on_resume(struct ata_port
 		 * there's no reason to evaluate IDE _GTF early
 		 * without _STM.  Clear cache and schedule _GTF.
 		 */
-		ata_link_for_each_dev(dev, &ap->link) {
+		ata_for_each_dev(dev, &ap->link, ALL) {
 			ata_acpi_clear_gtf(dev);
 			if (ata_dev_enabled(dev))
 				dev->flags |= ATA_DFLAG_ACPI_PENDING;
@@ -971,8 +968,8 @@ void ata_acpi_set_state(struct ata_port
 	if (state.event == PM_EVENT_ON)
 		acpi_bus_set_power(ap->acpi_handle, ACPI_STATE_D0);
 
-	ata_link_for_each_dev(dev, &ap->link) {
-		if (dev->acpi_handle && ata_dev_enabled(dev))
+	ata_for_each_dev(dev, &ap->link, ENABLED) {
+		if (dev->acpi_handle)
 			acpi_bus_set_power(dev->acpi_handle,
 				state.event == PM_EVENT_ON ?
 					ACPI_STATE_D0 : ACPI_STATE_D3);
Index: work/drivers/ata/libata-pmp.c
===================================================================
--- work.orig/drivers/ata/libata-pmp.c
+++ work/drivers/ata/libata-pmp.c
@@ -321,7 +321,7 @@ static void sata_pmp_quirks(struct ata_p
 
 	if (vendor == 0x1095 && devid == 0x3726) {
 		/* sil3726 quirks */
-		ata_port_for_each_link(link, ap) {
+		ata_for_each_link(link, ap, EDGE) {
 			/* Class code report is unreliable and SRST
 			 * times out under certain configurations.
 			 */
@@ -336,7 +336,7 @@ static void sata_pmp_quirks(struct ata_p
 		}
 	} else if (vendor == 0x1095 && devid == 0x4723) {
 		/* sil4723 quirks */
-		ata_port_for_each_link(link, ap) {
+		ata_for_each_link(link, ap, EDGE) {
 			/* class code report is unreliable */
 			if (link->pmp < 2)
 				link->flags |= ATA_LFLAG_ASSUME_ATA;
@@ -348,7 +348,7 @@ static void sata_pmp_quirks(struct ata_p
 		}
 	} else if (vendor == 0x1095 && devid == 0x4726) {
 		/* sil4726 quirks */
-		ata_port_for_each_link(link, ap) {
+		ata_for_each_link(link, ap, EDGE) {
 			/* Class code report is unreliable and SRST
 			 * times out under certain configurations.
 			 * Config device can be at port 0 or 5 and
@@ -450,7 +450,7 @@ int sata_pmp_attach(struct ata_device *d
 	if (ap->ops->pmp_attach)
 		ap->ops->pmp_attach(ap);
 
-	ata_port_for_each_link(tlink, ap)
+	ata_for_each_link(tlink, ap, EDGE)
 		sata_link_init_spd(tlink);
 
 	ata_acpi_associate_sata_port(ap);
@@ -487,7 +487,7 @@ static void sata_pmp_detach(struct ata_d
 	if (ap->ops->pmp_detach)
 		ap->ops->pmp_detach(ap);
 
-	ata_port_for_each_link(tlink, ap)
+	ata_for_each_link(tlink, ap, EDGE)
 		ata_eh_detach_dev(tlink->device);
 
 	spin_lock_irqsave(ap->lock, flags);
@@ -700,7 +700,7 @@ static int sata_pmp_eh_recover_pmp(struc
 		}
 
 		/* PMP is reset, SErrors cannot be trusted, scan all */
-		ata_port_for_each_link(tlink, ap) {
+		ata_for_each_link(tlink, ap, EDGE) {
 			struct ata_eh_context *ehc = &tlink->eh_context;
 
 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
@@ -768,7 +768,7 @@ static int sata_pmp_eh_handle_disabled_l
 
 	spin_lock_irqsave(ap->lock, flags);
 
-	ata_port_for_each_link(link, ap) {
+	ata_for_each_link(link, ap, EDGE) {
 		if (!(link->flags & ATA_LFLAG_DISABLED))
 			continue;
 
@@ -852,7 +852,7 @@ static int sata_pmp_eh_recover(struct at
 	int cnt, rc;
 
 	pmp_tries = ATA_EH_PMP_TRIES;
-	ata_port_for_each_link(link, ap)
+	ata_for_each_link(link, ap, EDGE)
 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 
  retry:
@@ -861,7 +861,7 @@ static int sata_pmp_eh_recover(struct at
 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
 				    ops->hardreset, ops->postreset, NULL);
 		if (rc) {
-			ata_link_for_each_dev(dev, &ap->link)
+			ata_for_each_dev(dev, &ap->link, ALL)
 				ata_dev_disable(dev);
 			return rc;
 		}
@@ -870,7 +870,7 @@ static int sata_pmp_eh_recover(struct at
 			return 0;
 
 		/* new PMP online */
-		ata_port_for_each_link(link, ap)
+		ata_for_each_link(link, ap, EDGE)
 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 
 		/* fall through */
@@ -942,7 +942,7 @@ static int sata_pmp_eh_recover(struct at
 	}
 
 	cnt = 0;
-	ata_port_for_each_link(link, ap) {
+	ata_for_each_link(link, ap, EDGE) {
 		if (!(gscr_error & (1 << link->pmp)))
 			continue;
 
Index: work/drivers/ata/libata-scsi.c
===================================================================
--- work.orig/drivers/ata/libata-scsi.c
+++ work/drivers/ata/libata-scsi.c
@@ -3228,12 +3228,12 @@ void ata_scsi_scan_host(struct ata_port
 		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))
@@ -3254,9 +3254,9 @@ void ata_scsi_scan_host(struct ata_port
 	 * 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;
 		}
 	}
@@ -3380,7 +3380,7 @@ static void ata_scsi_handle_link_detach(
 	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))
@@ -3495,7 +3495,7 @@ static int ata_scsi_user_scan(struct Scs
 	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;
@@ -3543,11 +3543,11 @@ void ata_scsi_dev_rescan(struct work_str
 
 	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;
Index: work/drivers/ata/pata_it821x.c
===================================================================
--- work.orig/drivers/ata/pata_it821x.c
+++ work/drivers/ata/pata_it821x.c
@@ -465,24 +465,22 @@ static int it821x_smart_set_mode(struct
 {
 	struct ata_device *dev;
 
-	ata_link_for_each_dev(dev, link) {
-		if (ata_dev_enabled(dev)) {
-			/* We don't really care */
-			dev->pio_mode = XFER_PIO_0;
-			dev->dma_mode = XFER_MW_DMA_0;
-			/* We do need the right mode information for DMA or PIO
-			   and this comes from the current configuration flags */
-			if (ata_id_has_dma(dev->id)) {
-				ata_dev_printk(dev, KERN_INFO, "configured for DMA\n");
-				dev->xfer_mode = XFER_MW_DMA_0;
-				dev->xfer_shift = ATA_SHIFT_MWDMA;
-				dev->flags &= ~ATA_DFLAG_PIO;
-			} else {
-				ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
-				dev->xfer_mode = XFER_PIO_0;
-				dev->xfer_shift = ATA_SHIFT_PIO;
-				dev->flags |= ATA_DFLAG_PIO;
-			}
+	ata_for_each_dev(dev, link, ENABLED) {
+		/* We don't really care */
+		dev->pio_mode = XFER_PIO_0;
+		dev->dma_mode = XFER_MW_DMA_0;
+		/* We do need the right mode information for DMA or PIO
+		   and this comes from the current configuration flags */
+		if (ata_id_has_dma(dev->id)) {
+			ata_dev_printk(dev, KERN_INFO, "configured for DMA\n");
+			dev->xfer_mode = XFER_MW_DMA_0;
+			dev->xfer_shift = ATA_SHIFT_MWDMA;
+			dev->flags &= ~ATA_DFLAG_PIO;
+		} else {
+			ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
+			dev->xfer_mode = XFER_PIO_0;
+			dev->xfer_shift = ATA_SHIFT_PIO;
+			dev->flags |= ATA_DFLAG_PIO;
 		}
 	}
 	return 0;
Index: work/drivers/ata/pata_ixp4xx_cf.c
===================================================================
--- work.orig/drivers/ata/pata_ixp4xx_cf.c
+++ work/drivers/ata/pata_ixp4xx_cf.c
@@ -30,14 +30,12 @@ static int ixp4xx_set_mode(struct ata_li
 {
 	struct ata_device *dev;
 
-	ata_link_for_each_dev(dev, link) {
-		if (ata_dev_enabled(dev)) {
-			ata_dev_printk(dev, KERN_INFO, "configured for PIO0\n");
-			dev->pio_mode = XFER_PIO_0;
-			dev->xfer_mode = XFER_PIO_0;
-			dev->xfer_shift = ATA_SHIFT_PIO;
-			dev->flags |= ATA_DFLAG_PIO;
-		}
+	ata_for_each_dev(dev, link, ENABLED) {
+		ata_dev_printk(dev, KERN_INFO, "configured for PIO0\n");
+		dev->pio_mode = XFER_PIO_0;
+		dev->xfer_mode = XFER_PIO_0;
+		dev->xfer_shift = ATA_SHIFT_PIO;
+		dev->flags |= ATA_DFLAG_PIO;
 	}
 	return 0;
 }
Index: work/drivers/ata/pata_legacy.c
===================================================================
--- work.orig/drivers/ata/pata_legacy.c
+++ work/drivers/ata/pata_legacy.c
@@ -194,15 +194,12 @@ static int legacy_set_mode(struct ata_li
 {
 	struct ata_device *dev;
 
-	ata_link_for_each_dev(dev, link) {
-		if (ata_dev_enabled(dev)) {
-			ata_dev_printk(dev, KERN_INFO,
-						"configured for PIO\n");
-			dev->pio_mode = XFER_PIO_0;
-			dev->xfer_mode = XFER_PIO_0;
-			dev->xfer_shift = ATA_SHIFT_PIO;
-			dev->flags |= ATA_DFLAG_PIO;
-		}
+	ata_for_each_dev(dev, link, ENABLED) {
+		ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
+		dev->pio_mode = XFER_PIO_0;
+		dev->xfer_mode = XFER_PIO_0;
+		dev->xfer_shift = ATA_SHIFT_PIO;
+		dev->flags |= ATA_DFLAG_PIO;
 	}
 	return 0;
 }
@@ -1028,7 +1025,7 @@ static __init int legacy_init_one(struct
 	/* Nothing found means we drop the port as its probably not there */
 
 	ret = -ENODEV;
-	ata_link_for_each_dev(dev, &ap->link) {
+	ata_for_each_dev(dev, &ap->link, ALL) {
 		if (!ata_dev_absent(dev)) {
 			legacy_host[probe->slot] = host;
 			ld->platform_dev = pdev;
Index: work/drivers/ata/pata_pdc2027x.c
===================================================================
--- work.orig/drivers/ata/pata_pdc2027x.c
+++ work/drivers/ata/pata_pdc2027x.c
@@ -406,23 +406,20 @@ static int pdc2027x_set_mode(struct ata_
 	if (rc < 0)
 		return rc;
 
-	ata_link_for_each_dev(dev, link) {
-		if (ata_dev_enabled(dev)) {
+	ata_for_each_dev(dev, link, ENABLED) {
+		pdc2027x_set_piomode(ap, dev);
 
-			pdc2027x_set_piomode(ap, dev);
+		/*
+		 * Enable prefetch if the device support PIO only.
+		 */
+		if (dev->xfer_shift == ATA_SHIFT_PIO) {
+			u32 ctcr1 = ioread32(dev_mmio(ap, dev, PDC_CTCR1));
+			ctcr1 |= (1 << 25);
+			iowrite32(ctcr1, dev_mmio(ap, dev, PDC_CTCR1));
 
-			/*
-			 * Enable prefetch if the device support PIO only.
-			 */
-			if (dev->xfer_shift == ATA_SHIFT_PIO) {
-				u32 ctcr1 = ioread32(dev_mmio(ap, dev, PDC_CTCR1));
-				ctcr1 |= (1 << 25);
-				iowrite32(ctcr1, dev_mmio(ap, dev, PDC_CTCR1));
-
-				PDPRINTK("Turn on prefetch\n");
-			} else {
-				pdc2027x_set_dmamode(ap, dev);
-			}
+			PDPRINTK("Turn on prefetch\n");
+		} else {
+			pdc2027x_set_dmamode(ap, dev);
 		}
 	}
 	return 0;
Index: work/drivers/ata/pata_platform.c
===================================================================
--- work.orig/drivers/ata/pata_platform.c
+++ work/drivers/ata/pata_platform.c
@@ -34,14 +34,12 @@ static int pata_platform_set_mode(struct
 {
 	struct ata_device *dev;
 
-	ata_link_for_each_dev(dev, link) {
-		if (ata_dev_enabled(dev)) {
-			/* We don't really care */
-			dev->pio_mode = dev->xfer_mode = XFER_PIO_0;
-			dev->xfer_shift = ATA_SHIFT_PIO;
-			dev->flags |= ATA_DFLAG_PIO;
-			ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
-		}
+	ata_for_each_dev(dev, link, ENABLED) {
+		/* We don't really care */
+		dev->pio_mode = dev->xfer_mode = XFER_PIO_0;
+		dev->xfer_shift = ATA_SHIFT_PIO;
+		dev->flags |= ATA_DFLAG_PIO;
+		ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
 	}
 	return 0;
 }
Index: work/drivers/ata/pata_rz1000.c
===================================================================
--- work.orig/drivers/ata/pata_rz1000.c
+++ work/drivers/ata/pata_rz1000.c
@@ -38,15 +38,13 @@ static int rz1000_set_mode(struct ata_li
 {
 	struct ata_device *dev;
 
-	ata_link_for_each_dev(dev, link) {
-		if (ata_dev_enabled(dev)) {
-			/* We don't really care */
-			dev->pio_mode = XFER_PIO_0;
-			dev->xfer_mode = XFER_PIO_0;
-			dev->xfer_shift = ATA_SHIFT_PIO;
-			dev->flags |= ATA_DFLAG_PIO;
-			ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
-		}
+	ata_for_each_dev(dev, link, ENABLED) {
+		/* We don't really care */
+		dev->pio_mode = XFER_PIO_0;
+		dev->xfer_mode = XFER_PIO_0;
+		dev->xfer_shift = ATA_SHIFT_PIO;
+		dev->flags |= ATA_DFLAG_PIO;
+		ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
 	}
 	return 0;
 }
Index: work/drivers/ata/sata_sil.c
===================================================================
--- work.orig/drivers/ata/sata_sil.c
+++ work/drivers/ata/sata_sil.c
@@ -278,7 +278,7 @@ static int sil_set_mode(struct ata_link
 	if (rc)
 		return rc;
 
-	ata_link_for_each_dev(dev, link) {
+	ata_for_each_dev(dev, link, ALL) {
 		if (!ata_dev_enabled(dev))
 			dev_mode[dev->devno] = 0;	/* PIO0/1/2 */
 		else if (dev->flags & ATA_DFLAG_PIO)

[PATCH #upstream-fixes 3/4] libata: when restoring SControl during detach do the PMP links first

[Tejun Heo]

When restoring SControl during detach, PMP links should be handled
first as changing SControl of the host link can affect SCR access of
PMP links.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 drivers/ata/libata-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: work/drivers/ata/libata-core.c
===================================================================
--- work.orig/drivers/ata/libata-core.c
+++ work/drivers/ata/libata-core.c
@@ -6035,7 +6035,7 @@ static void ata_port_detach(struct ata_p
 	/* EH is now guaranteed to see UNLOADING - EH context belongs
 	 * to us.  Restore SControl and disable all existing devices.
 	 */
-	ata_for_each_link(link, ap, HOST_FIRST) {
+	ata_for_each_link(link, ap, PMP_FIRST) {
 		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol);
 		ata_for_each_dev(dev, link, ALL)
 			ata_dev_disable(dev);

[PATCH #upstream-fixes 4/4] libata: perform port detach in EH

[Tejun Heo]

ata_port_detach() first made sure EH saw ATA_PFLAG_UNLOADING and then
assumed EH context belongs to it and performed detach operation
itself.  However, UNLOADING doesn't disable all of EH and this could
lead to problems including triggering WARN_ON()'s in EH path.

This patch makes port detach behave more like other EH actions such
that ata_port_detach() requests EH to detach and waits for completion.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 drivers/ata/libata-core.c |   23 ++++-------------------
 drivers/ata/libata-eh.c   |   32 +++++++++++++++++++++++++++++++-
 include/linux/libata.h    |    3 ++-
 3 files changed, 37 insertions(+), 21 deletions(-)

Index: work/drivers/ata/libata-eh.c
===================================================================
--- work.orig/drivers/ata/libata-eh.c
+++ work/drivers/ata/libata-eh.c
@@ -491,6 +491,31 @@ enum blk_eh_timer_return ata_scsi_timed_
 	return ret;
 }
 
+static void ata_eh_unload(struct ata_port *ap)
+{
+	struct ata_link *link;
+	struct ata_device *dev;
+	unsigned long flags;
+
+	/* Restore SControl IPM and SPD for the next driver and
+	 * disable attached devices.
+	 */
+	ata_for_each_link(link, ap, PMP_FIRST) {
+		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
+		ata_for_each_dev(dev, link, ALL)
+			ata_dev_disable(dev);
+	}
+
+	/* freeze and set UNLOADED */
+	spin_lock_irqsave(ap->lock, flags);
+
+	ata_port_freeze(ap);			/* won't be thawed */
+	ap->pflags &= ~ATA_PFLAG_EH_PENDING;	/* clear pending from freeze */
+	ap->pflags |= ATA_PFLAG_UNLOADED;
+
+	spin_unlock_irqrestore(ap->lock, flags);
+}
+
 /**
  *	ata_scsi_error - SCSI layer error handler callback
  *	@host: SCSI host on which error occurred
@@ -621,8 +646,13 @@ void ata_scsi_error(struct Scsi_Host *ho
 		/* invoke EH, skip if unloading or suspended */
 		if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
 			ap->ops->error_handler(ap);
-		else
+		else {
+			/* if unloading, commence suicide */
+			if ((ap->pflags & ATA_PFLAG_UNLOADING) &&
+			    !(ap->pflags & ATA_PFLAG_UNLOADED))
+				ata_eh_unload(ap);
 			ata_eh_finish(ap);
+		}
 
 		/* process port suspend request */
 		ata_eh_handle_port_suspend(ap);
Index: work/include/linux/libata.h
===================================================================
--- work.orig/include/linux/libata.h
+++ work/include/linux/libata.h
@@ -213,10 +213,11 @@ enum {
 	ATA_PFLAG_FROZEN	= (1 << 2), /* port is frozen */
 	ATA_PFLAG_RECOVERED	= (1 << 3), /* recovery action performed */
 	ATA_PFLAG_LOADING	= (1 << 4), /* boot/loading probe */
-	ATA_PFLAG_UNLOADING	= (1 << 5), /* module is unloading */
 	ATA_PFLAG_SCSI_HOTPLUG	= (1 << 6), /* SCSI hotplug scheduled */
 	ATA_PFLAG_INITIALIZING	= (1 << 7), /* being initialized, don't touch */
 	ATA_PFLAG_RESETTING	= (1 << 8), /* reset in progress */
+	ATA_PFLAG_UNLOADING	= (1 << 9), /* driver is being unloaded */
+	ATA_PFLAG_UNLOADED	= (1 << 10), /* driver is unloaded */
 
 	ATA_PFLAG_SUSPENDED	= (1 << 17), /* port is suspended (power) */
 	ATA_PFLAG_PM_PENDING	= (1 << 18), /* PM operation pending */
Index: work/drivers/ata/libata-core.c
===================================================================
--- work.orig/drivers/ata/libata-core.c
+++ work/drivers/ata/libata-core.c
@@ -6019,8 +6019,6 @@ int ata_host_activate(struct ata_host *h
 static void ata_port_detach(struct ata_port *ap)
 {
 	unsigned long flags;
-	struct ata_link *link;
-	struct ata_device *dev;
 
 	if (!ap->ops->error_handler)
 		goto skip_eh;
@@ -6028,28 +6026,15 @@ static void ata_port_detach(struct ata_p
 	/* tell EH we're leaving & flush EH */
 	spin_lock_irqsave(ap->lock, flags);
 	ap->pflags |= ATA_PFLAG_UNLOADING;
+	ata_port_schedule_eh(ap);
 	spin_unlock_irqrestore(ap->lock, flags);
 
+	/* wait till EH commits suicide */
 	ata_port_wait_eh(ap);
 
-	/* EH is now guaranteed to see UNLOADING - EH context belongs
-	 * to us.  Restore SControl and disable all existing devices.
-	 */
-	ata_for_each_link(link, ap, PMP_FIRST) {
-		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol);
-		ata_for_each_dev(dev, link, ALL)
-			ata_dev_disable(dev);
-	}
-
-	/* Final freeze & EH.  All in-flight commands are aborted.  EH
-	 * will be skipped and retrials will be terminated with bad
-	 * target.
-	 */
-	spin_lock_irqsave(ap->lock, flags);
-	ata_port_freeze(ap);	/* won't be thawed */
-	spin_unlock_irqrestore(ap->lock, flags);
+	/* it better be dead now */
+	WARN_ON(!(ap->pflags & ATA_PFLAG_UNLOADED));
 
-	ata_port_wait_eh(ap);
 	cancel_rearming_delayed_work(&ap->hotplug_task);
 
  skip_eh:

Re: [PATCH #upstream-fixes 4/4] libata: perform port detach in EH

[Jeff Garzik]

Tejun Heo wrote:
> ata_port_detach() first made sure EH saw ATA_PFLAG_UNLOADING and then
> assumed EH context belongs to it and performed detach operation
> itself.  However, UNLOADING doesn't disable all of EH and this could
> lead to problems including triggering WARN_ON()'s in EH path.
> 
> This patch makes port detach behave more like other EH actions such
> that ata_port_detach() requests EH to detach and waits for completion.
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> ---
>  drivers/ata/libata-core.c |   23 ++++-------------------
>  drivers/ata/libata-eh.c   |   32 +++++++++++++++++++++++++++++++-
>  include/linux/libata.h    |    3 ++-
>  3 files changed, 37 insertions(+), 21 deletions(-)

dropped patches 3-4 as well, due to dropping patch #2

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Elias Oltmanns]

Tejun Heo <tj@kernel.org> wrote:
> There currently are the following loop 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 loop 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>
> ---
[...]
> Index: work/drivers/ata/libata-core.c
> ===================================================================
> --- work.orig/drivers/ata/libata-core.c
> +++ work/drivers/ata/libata-core.c
[...]
> @@ -1107,8 +1183,8 @@ static void ata_lpm_enable(struct ata_ho
>  
>  	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)

Where did these short forms (EDGE, ALL) spring from? Does this code even
compile?

[...]
> Index: work/drivers/ata/libata-eh.c
> ===================================================================
> --- work.orig/drivers/ata/libata-eh.c
> +++ work/drivers/ata/libata-eh.c
[...]
> @@ -2880,9 +2871,8 @@ static int ata_link_nr_enabled(struct at
>  	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;
>  }
>  
> @@ -2891,7 +2881,7 @@ static int ata_link_nr_vacant(struct ata
>  	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;

What about making the two above (ata_link_nr_*()) static inline while
you are at it? Or is this another one of those cases where the compiler
knows best anyway?

[...]
> Index: work/drivers/ata/libata-scsi.c
> ===================================================================
> --- work.orig/drivers/ata/libata-scsi.c
> +++ work/drivers/ata/libata-scsi.c
[...]
> @@ -3254,9 +3254,9 @@ void ata_scsi_scan_host(struct ata_port
>  	 * 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;
>  		}
>  	}

Getting rid of those braces would make things even cleaner in my
opinion. (That's my nit picking since Sergei picked on that comment
formatting issue shortly before I was going to ;-) ).

Regards,

Elias

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Tejun Heo]

Hello,

Elias Oltmanns wrote:
>> -		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)
> 
> Where did these short forms (EDGE, ALL) spring from? Does this code even
> compile?

+#define ata_for_each_link(link, ap, mode) \
+	for ((link) = ata_link_next(NULL, (ap), ATA_LITER_##mode); (link); \
+	     (link) = ata_link_next((link), (ap), ATA_LITER_##mode))
+
+#define ata_for_each_dev(dev, link, mode) \
+	for ((dev) = ata_dev_next(NULL, (link), ATA_DITER_##mode); (dev); \
+	     (dev) = ata_dev_next((dev), (link), ATA_DITER_##mode))

>> @@ -2891,7 +2881,7 @@ static int ata_link_nr_vacant(struct ata
>>  	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;
> 
> What about making the two above (ata_link_nr_*()) static inline while
> you are at it? Or is this another one of those cases where the compiler
> knows best anyway?

Yeah, it's a static function used only in single place.  Should be
pretty straight forward for the compiler and even if it fails to
notice it, it doesn't hurt at all.

> [...]
>> Index: work/drivers/ata/libata-scsi.c
>> ===================================================================
>> --- work.orig/drivers/ata/libata-scsi.c
>> +++ work/drivers/ata/libata-scsi.c
> [...]
>> @@ -3254,9 +3254,9 @@ void ata_scsi_scan_host(struct ata_port
>>  	 * 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;
>>  		}
>>  	}
> 
> Getting rid of those braces would make things even cleaner in my
> opinion. (That's my nit picking since Sergei picked on that comment
> formatting issue shortly before I was going to ;-) ).

Yeah, maybe.  I don't know.  The reason why I added braces there in
the first place was because emacs has some problem dealing with nested
non-standard looping constructs.

Thanks.

-- 
tejun

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Elias Oltmanns]

Tejun Heo <tj@kernel.org> wrote:
> Hello,
>
> Elias Oltmanns wrote:
>>> -		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)
>> 
>> Where did these short forms (EDGE, ALL) spring from? Does this code even
>> compile?
>
> +#define ata_for_each_link(link, ap, mode) \
> +	for ((link) = ata_link_next(NULL, (ap), ATA_LITER_##mode); (link); \
> +	     (link) = ata_link_next((link), (ap), ATA_LITER_##mode))
> +
> +#define ata_for_each_dev(dev, link, mode) \
> +	for ((dev) = ata_dev_next(NULL, (link), ATA_DITER_##mode); (dev); \
> +	     (dev) = ata_dev_next((dev), (link), ATA_DITER_##mode))

Sorry, I should have been more explicit. I was referring to EDGE and ALL
as opposed to ATA_LITER_EDGE and ATA_DITER_ALL. Unless I've missed
something, the former aren't defined anywhere in your patch.

>
>>> @@ -2891,7 +2881,7 @@ static int ata_link_nr_vacant(struct ata
>>>  	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;
>> 
>> What about making the two above (ata_link_nr_*()) static inline while
>> you are at it? Or is this another one of those cases where the compiler
>> knows best anyway?
>
> Yeah, it's a static function used only in single place.  Should be
> pretty straight forward for the compiler and even if it fails to
> notice it, it doesn't hurt at all.

I should have guessed, I suppose. Probably just was too lazy to check,
sorry.

>
>> [...]
>>> Index: work/drivers/ata/libata-scsi.c
>>> ===================================================================
>>> --- work.orig/drivers/ata/libata-scsi.c
>>> +++ work/drivers/ata/libata-scsi.c
>> [...]
>>> @@ -3254,9 +3254,9 @@ void ata_scsi_scan_host(struct ata_port
>>>  	 * 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;
>>>  		}
>>>  	}
>> 
>> Getting rid of those braces would make things even cleaner in my
>> opinion. (That's my nit picking since Sergei picked on that comment
>> formatting issue shortly before I was going to ;-) ).
>
> Yeah, maybe.  I don't know.  The reason why I added braces there in
> the first place was because emacs has some problem dealing with nested
> non-standard looping constructs.

Right, I seem to remember having trouble with that myself. So I'm all in
favour of keeping them after all ;-).

Regards,

Elias

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Tejun Heo]

Elias Oltmanns wrote:
> Tejun Heo <tj@kernel.org> wrote:
>> Hello,
>>
>> Elias Oltmanns wrote:
>>>> -		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)
>>> Where did these short forms (EDGE, ALL) spring from? Does this code even
>>> compile?
>> +#define ata_for_each_link(link, ap, mode) \
>> +	for ((link) = ata_link_next(NULL, (ap), ATA_LITER_##mode); (link); \
>> +	     (link) = ata_link_next((link), (ap), ATA_LITER_##mode))
>> +
>> +#define ata_for_each_dev(dev, link, mode) \
>> +	for ((dev) = ata_dev_next(NULL, (link), ATA_DITER_##mode); (dev); \
>> +	     (dev) = ata_dev_next((dev), (link), ATA_DITER_##mode))
> 
> Sorry, I should have been more explicit. I was referring to EDGE and ALL
> as opposed to ATA_LITER_EDGE and ATA_DITER_ALL. Unless I've missed
> something, the former aren't defined anywhere in your patch.

I seriously can't be more explicit.  Please take a shower and read my
reply again, especially, the "ATA_[LD]ITER_##mode" part.  :-)

-- 
tejun

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Elias Oltmanns]

Tejun Heo <tj@kernel.org> wrote:
> Elias Oltmanns wrote:
>> Tejun Heo <tj@kernel.org> wrote:
>
>>> Hello,
>>>
>>> Elias Oltmanns wrote:
>>>>> -		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)
>>>> Where did these short forms (EDGE, ALL) spring from? Does this code even
>>>> compile?
>>> +#define ata_for_each_link(link, ap, mode) \
>>> +	for ((link) = ata_link_next(NULL, (ap), ATA_LITER_##mode); (link); \
>>> +	     (link) = ata_link_next((link), (ap), ATA_LITER_##mode))
>>> +
>>> +#define ata_for_each_dev(dev, link, mode) \
>>> +	for ((dev) = ata_dev_next(NULL, (link), ATA_DITER_##mode); (dev); \
>>> +	     (dev) = ata_dev_next((dev), (link), ATA_DITER_##mode))
>> 
>> Sorry, I should have been more explicit. I was referring to EDGE and ALL
>> as opposed to ATA_LITER_EDGE and ATA_DITER_ALL. Unless I've missed
>> something, the former aren't defined anywhere in your patch.
>
> I seriously can't be more explicit.  Please take a shower and read my
> reply again, especially, the "ATA_[LD]ITER_##mode" part.  :-)

Oh dear, I really need to drop that idea that a macro does what I think
it does. Sorry for the noise.

Regards,

Elias

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Jeff Garzik]

Tejun Heo wrote:
> There currently are the following loop 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 loop 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>
> ---
>  drivers/ata/ahci.c           |    8 -
>  drivers/ata/ata_generic.c    |    5 -
>  drivers/ata/libata-acpi.c    |   19 +---
>  drivers/ata/libata-core.c    |  183 ++++++++++++++++++++++++++++---------------
>  drivers/ata/libata-eh.c      |   84 ++++++++-----------
>  drivers/ata/libata-pmp.c     |   22 ++---
>  drivers/ata/libata-scsi.c    |   22 ++---
>  drivers/ata/pata_it821x.c    |   34 +++----
>  drivers/ata/pata_ixp4xx_cf.c |   14 +--
>  drivers/ata/pata_legacy.c    |   17 +--
>  drivers/ata/pata_pdc2027x.c  |   27 ++----
>  drivers/ata/pata_platform.c  |   14 +--
>  drivers/ata/pata_rz1000.c    |   16 +--
>  drivers/ata/sata_sil.c       |    2 
>  include/linux/libata.h       |   50 +++++++----
>  15 files changed, 279 insertions(+), 238 deletions(-)

ACK... for 2.6.29.  I think this is too much change for -rc2.  It's a 
good idea though.

Also, it could use more documentation than just the commit message... 
something that programmers can easily refer to (header file comment?)

	Jeff

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Mark Lord]

Jeff Garzik wrote:
> Tejun Heo wrote:
>> There currently are the following loop 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 loop 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>
>> ---
>>  drivers/ata/ahci.c           |    8 -
>>  drivers/ata/ata_generic.c    |    5 -
>>  drivers/ata/libata-acpi.c    |   19 +---
>>  drivers/ata/libata-core.c    |  183 
>> ++++++++++++++++++++++++++++---------------
>>  drivers/ata/libata-eh.c      |   84 ++++++++-----------
>>  drivers/ata/libata-pmp.c     |   22 ++---
>>  drivers/ata/libata-scsi.c    |   22 ++---
>>  drivers/ata/pata_it821x.c    |   34 +++----
>>  drivers/ata/pata_ixp4xx_cf.c |   14 +--
>>  drivers/ata/pata_legacy.c    |   17 +--
>>  drivers/ata/pata_pdc2027x.c  |   27 ++----
>>  drivers/ata/pata_platform.c  |   14 +--
>>  drivers/ata/pata_rz1000.c    |   16 +--
>>  drivers/ata/sata_sil.c       |    2  include/linux/libata.h       |   
>> 50 +++++++----
>>  15 files changed, 279 insertions(+), 238 deletions(-)
> 
> ACK... for 2.6.29.  I think this is too much change for -rc2.  It's a 
> good idea though.
> 
> Also, it could use more documentation than just the commit message... 
> something that programmers can easily refer to (header file comment?)
..

Yeah.  Especially a reminder of what "LITER" and "DITER" stand for!  :)

Cheers

Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Jeff Garzik]

Mark Lord wrote:
> Jeff Garzik wrote:
>> Tejun Heo wrote:
>>> There currently are the following loop 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 loop 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>
>>> ---
>>>  drivers/ata/ahci.c           |    8 -
>>>  drivers/ata/ata_generic.c    |    5 -
>>>  drivers/ata/libata-acpi.c    |   19 +---
>>>  drivers/ata/libata-core.c    |  183 
>>> ++++++++++++++++++++++++++++---------------
>>>  drivers/ata/libata-eh.c      |   84 ++++++++-----------
>>>  drivers/ata/libata-pmp.c     |   22 ++---
>>>  drivers/ata/libata-scsi.c    |   22 ++---
>>>  drivers/ata/pata_it821x.c    |   34 +++----
>>>  drivers/ata/pata_ixp4xx_cf.c |   14 +--
>>>  drivers/ata/pata_legacy.c    |   17 +--
>>>  drivers/ata/pata_pdc2027x.c  |   27 ++----
>>>  drivers/ata/pata_platform.c  |   14 +--
>>>  drivers/ata/pata_rz1000.c    |   16 +--
>>>  drivers/ata/sata_sil.c       |    2  include/linux/libata.h       
>>> |   50 +++++++----
>>>  15 files changed, 279 insertions(+), 238 deletions(-)
>>
>> ACK... for 2.6.29.  I think this is too much change for -rc2.  It's a 
>> good idea though.
>>
>> Also, it could use more documentation than just the commit message... 
>> something that programmers can easily refer to (header file comment?)
> ..
> 
> Yeah.  Especially a reminder of what "LITER" and "DITER" stand for!  :)

Well, DITER stands for device iteration, and LITER stands for an amount 
of petrol... <grin>

	Jeff

Re: [PATCH #upstream-fixes 1/4] libata: fix device iteration bugs

[Sergei Shtylyov]

Hello.

Tejun Heo wrote:

> There were several places where only enabled devices should be
> iterated over but device enabledness wasn't checked.
>
> * IDENTIFY data 40 wire check in cable_is_40wire()
> * xfer_mode/ncq_enabled saving in ata_scsi_error()
> * DUBIOUS_XFER handling in ata_set_mode()
>
> While at it, reformat comment in cable_is_40wire().
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
>   

   More nitpicking... :-)

> Index: work/drivers/ata/libata-core.c
> ===================================================================
> --- work.orig/drivers/ata/libata-core.c
> +++ work/drivers/ata/libata-core.c
> @@ -4169,18 +4169,16 @@ static int cable_is_40wire(struct ata_po
>  	if (ap->cbl == ATA_CBL_PATA40_SHORT)
>  		return 0;
>  	/* If the controller doesn't know we scan
> -
> -	   - Note: We look for all 40 wire detects at this point.
> -	     Any 80 wire detect is taken to be 80 wire cable
> -	     because
> -	     - In many setups only the one drive (slave if present)
> -               will give a valid detect
> -             - If you have a non detect capable drive you don't
> -               want it to colour the choice
> -        */
> +	 *
> +	 * - Note: We look for all 40 wire detects at this point.  Any
> +	 *   80 wire detect is taken to be 80 wire cable because - In
> +	 *   many setups only the one drive (slave if present) will
> +	 *   give a valid detect - If you have a non detect capable
> +	 *   drive you don't want it to colour the choice
> +	 */
>   

   The comment formatting  now is worse than it was... I'd drop hyphen 
before "Note:" and align the bullets under this note (also doing s/If/if/).

MBR, Sergei

Re: [PATCH #upstream-fixes 1/4] libata: fix device iteration bugs

[Tejun Heo]

Sergei Shtylyov wrote:
> Hello.
> 
> Tejun Heo wrote:
> 
>> There were several places where only enabled devices should be
>> iterated over but device enabledness wasn't checked.
>>
>> * IDENTIFY data 40 wire check in cable_is_40wire()
>> * xfer_mode/ncq_enabled saving in ata_scsi_error()
>> * DUBIOUS_XFER handling in ata_set_mode()
>>
>> While at it, reformat comment in cable_is_40wire().
>>
>> Signed-off-by: Tejun Heo <tj@kernel.org>
>>   
> 
>   More nitpicking... :-)
> 
>> Index: work/drivers/ata/libata-core.c
>> ===================================================================
>> --- work.orig/drivers/ata/libata-core.c
>> +++ work/drivers/ata/libata-core.c
>> @@ -4169,18 +4169,16 @@ static int cable_is_40wire(struct ata_po
>>      if (ap->cbl == ATA_CBL_PATA40_SHORT)
>>          return 0;
>>      /* If the controller doesn't know we scan
>> -
>> -       - Note: We look for all 40 wire detects at this point.
>> -         Any 80 wire detect is taken to be 80 wire cable
>> -         because
>> -         - In many setups only the one drive (slave if present)
>> -               will give a valid detect
>> -             - If you have a non detect capable drive you don't
>> -               want it to colour the choice
>> -        */
>> +     *
>> +     * - Note: We look for all 40 wire detects at this point.  Any
>> +     *   80 wire detect is taken to be 80 wire cable because - In
>> +     *   many setups only the one drive (slave if present) will
>> +     *   give a valid detect - If you have a non detect capable
>> +     *   drive you don't want it to colour the choice
>> +     */
>>   
> 
>   The comment formatting  now is worse than it was... I'd drop hyphen
> before "Note:" and align the bullets under this note (also doing s/If/if/).

Yeah, somehow I missed those bullets altogether.  Will regenerate the
patch.  Thanks.

-- 
tejun

[PATCH #upstream-fixes 1/4 UPDATED] libata: fix device iteration bugs

[Tejun Heo]

There were several places where only enabled devices should be
iterated over but device enabledness wasn't checked.

* IDENTIFY data 40 wire check in cable_is_40wire()
* xfer_mode/ncq_enabled saving in ata_scsi_error()
* DUBIOUS_XFER handling in ata_set_mode()

While at it, reformat comments in cable_is_40wire().

Signed-off-by: Tejun Heo <tj@kernel.org>
---
Comments reformatted as per Sergei's comment.

 drivers/ata/libata-core.c |   32 ++++++++++++++++++--------------
 drivers/ata/libata-eh.c   |    9 +++++++++
 2 files changed, 27 insertions(+), 14 deletions(-)

Index: work/drivers/ata/libata-core.c
===================================================================
--- work.orig/drivers/ata/libata-core.c
+++ work/drivers/ata/libata-core.c
@@ -4158,29 +4158,33 @@ static int cable_is_40wire(struct ata_po
 	struct ata_link *link;
 	struct ata_device *dev;
 
-	/* If the controller thinks we are 40 wire, we are */
+	/* If the controller thinks we are 40 wire, we are. */
 	if (ap->cbl == ATA_CBL_PATA40)
 		return 1;
-	/* If the controller thinks we are 80 wire, we are */
+
+	/* If the controller thinks we are 80 wire, we are. */
 	if (ap->cbl == ATA_CBL_PATA80 || ap->cbl == ATA_CBL_SATA)
 		return 0;
-	/* If the system is known to be 40 wire short cable (eg laptop),
-	   then we allow 80 wire modes even if the drive isn't sure */
+
+	/* If the system is known to be 40 wire short cable (eg
+	 * laptop), then we allow 80 wire modes even if the drive
+	 * isn't sure.
+	 */
 	if (ap->cbl == ATA_CBL_PATA40_SHORT)
 		return 0;
-	/* If the controller doesn't know we scan
 
-	   - Note: We look for all 40 wire detects at this point.
-	     Any 80 wire detect is taken to be 80 wire cable
-	     because
-	     - In many setups only the one drive (slave if present)
-               will give a valid detect
-             - If you have a non detect capable drive you don't
-               want it to colour the choice
-        */
+	/* If the controller doesn't know, we scan.
+	 *
+	 * Note: We look for all 40 wire detects at this point.  Any
+	 *       80 wire detect is taken to be 80 wire cable because
+	 * - in many setups only the one drive (slave if present) will
+	 *   give a valid detect
+	 * - 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_is_40wire(dev))
+			if (ata_dev_enabled(dev) && !ata_is_40wire(dev))
 				return 0;
 		}
 	}
Index: work/drivers/ata/libata-eh.c
===================================================================
--- work.orig/drivers/ata/libata-eh.c
+++ work/drivers/ata/libata-eh.c
@@ -603,6 +603,9 @@ void ata_scsi_error(struct Scsi_Host *ho
 			ata_link_for_each_dev(dev, link) {
 				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;
@@ -2790,6 +2793,9 @@ int ata_set_mode(struct ata_link *link,
 
 	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
 	ata_link_for_each_dev(dev, link) {
+		if (!ata_dev_enabled(dev))
+			continue;
+
 		if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
 			struct ata_ering_entry *ent;
 
@@ -2811,6 +2817,9 @@ int ata_set_mode(struct ata_link *link,
 		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;

Re: [PATCH #upstream-fixes 1/4 UPDATED] libata: fix device iteration bugs

[Jeff Garzik]

Tejun Heo wrote:
> There were several places where only enabled devices should be
> iterated over but device enabledness wasn't checked.
> 
> * IDENTIFY data 40 wire check in cable_is_40wire()
> * xfer_mode/ncq_enabled saving in ata_scsi_error()
> * DUBIOUS_XFER handling in ata_set_mode()
> 
> While at it, reformat comments in cable_is_40wire().
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> ---
> Comments reformatted as per Sergei's comment.
> 
>  drivers/ata/libata-core.c |   32 ++++++++++++++++++--------------
>  drivers/ata/libata-eh.c   |    9 +++++++++
>  2 files changed, 27 insertions(+), 14 deletions(-)

applied