From 82ef04fb4c82542b3eda81cca461f0594ce9cd0b Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 31 Jul 2008 17:02:40 +0900
Subject: libata: make SCR access ops per-link

Logically, SCR access ops should take @link; however, there was no
compelling reason to convert all SCR access ops when adding @link
abstraction as there's one-to-one mapping between a port and a non-PMP
link.  However, that assumption won't hold anymore with the scheduled
addition of slave link.

Make SCR access ops per-link.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 include/linux/libata.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'include/linux/libata.h')

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 225bfc5bd9e..ffd622fa319 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -772,8 +772,8 @@ struct ata_port_operations {
 	/*
 	 * Optional features
 	 */
-	int  (*scr_read)(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-	int  (*scr_write)(struct ata_port *ap, unsigned int sc_reg, u32 val);
+	int  (*scr_read)(struct ata_link *link, unsigned int sc_reg, u32 *val);
+	int  (*scr_write)(struct ata_link *link, unsigned int sc_reg, u32 val);
 	void (*pmp_attach)(struct ata_port *ap);
 	void (*pmp_detach)(struct ata_port *ap);
 	int  (*enable_pm)(struct ata_port *ap, enum link_pm policy);
-- 
cgit v1.2.3-70-g09d2


From aadffb682cc5572f48cc24883681db65530bd284 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 31 Jul 2008 17:02:41 +0900
Subject: libata: reimplement link iterator

Implement __ata_port_next_link() and reimplement
__ata_port_for_each_link() and ata_port_for_each_link() using it.
This removes relatively large inlined code and makes iteration easier
to extend.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 drivers/ata/libata-core.c | 30 ++++++++++++++++++++++++++++++
 include/linux/libata.h    | 33 ++++++++-------------------------
 2 files changed, 38 insertions(+), 25 deletions(-)

(limited to 'include/linux/libata.h')

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 825461a33ab..d156616f45f 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -163,6 +163,35 @@ MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
 
 
+/*
+ * Iterator helpers.  Don't use directly.
+ *
+ * LOCKING:
+ * Host lock or EH context.
+ */
+struct ata_link *__ata_port_next_link(struct ata_port *ap,
+				      struct ata_link *link, bool dev_only)
+{
+	/* NULL link indicates start of iteration */
+	if (!link) {
+		if (dev_only && sata_pmp_attached(ap))
+			return ap->pmp_link;
+		return &ap->link;
+	}
+
+	/* we just iterated over the host link, what's next? */
+	if (ata_is_host_link(link)) {
+		if (!sata_pmp_attached(ap))
+			return NULL;
+		return ap->pmp_link;
+	}
+
+	/* iterate to the next PMP link */
+	if (++link < ap->pmp_link + ap->nr_pmp_links)
+		return link;
+	return NULL;
+}
+
 /**
  *	ata_force_cbl - force cable type according to libata.force
  *	@ap: ATA port of interest
@@ -6255,6 +6284,7 @@ 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_std_bios_param);
 EXPORT_SYMBOL_GPL(ata_host_init);
 EXPORT_SYMBOL_GPL(ata_host_alloc);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index ffd622fa319..3eaca347ce2 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1265,34 +1265,17 @@ static inline int ata_link_active(struct ata_link *link)
 	return ata_tag_valid(link->active_tag) || link->sactive;
 }
 
-static inline struct ata_link *ata_port_first_link(struct ata_port *ap)
-{
-	if (sata_pmp_attached(ap))
-		return ap->pmp_link;
-	return &ap->link;
-}
-
-static inline struct ata_link *ata_port_next_link(struct ata_link *link)
-{
-	struct ata_port *ap = link->ap;
-
-	if (ata_is_host_link(link)) {
-		if (!sata_pmp_attached(ap))
-			return NULL;
-		return ap->pmp_link;
-	}
-
-	if (++link < ap->nr_pmp_links + ap->pmp_link)
-		return link;
-	return NULL;
-}
+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(lk, ap) \
-	for ((lk) = &(ap)->link; (lk); (lk) = ata_port_next_link(lk))
+#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_first_link(ap); (link); \
-	     (link) = ata_port_next_link(link))
+	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; \
-- 
cgit v1.2.3-70-g09d2


From b5b3fa386b8f96c7fa92e507e5deddc2637924b4 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 31 Jul 2008 17:02:42 +0900
Subject: libata: misc updates to prepare for slave link

* Add ATA_EH_ALL_ACTIONS.

* Make sata_link_{on|off}_line() return bool instead of int.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 drivers/ata/libata-core.c | 16 ++++++++--------
 include/linux/libata.h    |  6 ++++--
 2 files changed, 12 insertions(+), 10 deletions(-)

(limited to 'include/linux/libata.h')

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index d156616f45f..71024e94c57 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4976,16 +4976,16 @@ int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
  *	None.
  *
  *	RETURNS:
- *	1 if the port online status is available and online.
+ *	True if the port online status is available and online.
  */
-int ata_link_online(struct ata_link *link)
+bool ata_link_online(struct ata_link *link)
 {
 	u32 sstatus;
 
 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
 	    (sstatus & 0xf) == 0x3)
-		return 1;
-	return 0;
+		return true;
+	return false;
 }
 
 /**
@@ -5000,16 +5000,16 @@ int ata_link_online(struct ata_link *link)
  *	None.
  *
  *	RETURNS:
- *	1 if the port offline status is available and offline.
+ *	True if the port offline status is available and offline.
  */
-int ata_link_offline(struct ata_link *link)
+bool ata_link_offline(struct ata_link *link)
 {
 	u32 sstatus;
 
 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
 	    (sstatus & 0xf) != 0x3)
-		return 1;
-	return 0;
+		return true;
+	return false;
 }
 
 #ifdef CONFIG_PM
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 3eaca347ce2..0c7e6f3c28e 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -321,6 +321,8 @@ enum {
 	ATA_EH_LPM		= (1 << 4),  /* link power management action */
 
 	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE,
+	ATA_EH_ALL_ACTIONS	= ATA_EH_REVALIDATE | ATA_EH_RESET |
+				  ATA_EH_ENABLE_LINK | ATA_EH_LPM,
 
 	/* ata_eh_info->flags */
 	ATA_EHI_HOTPLUGGED	= (1 << 0),  /* could have been hotplugged */
@@ -920,8 +922,8 @@ extern int sata_scr_valid(struct ata_link *link);
 extern int sata_scr_read(struct ata_link *link, int reg, u32 *val);
 extern int sata_scr_write(struct ata_link *link, int reg, u32 val);
 extern int sata_scr_write_flush(struct ata_link *link, int reg, u32 val);
-extern int ata_link_online(struct ata_link *link);
-extern int ata_link_offline(struct ata_link *link);
+extern bool ata_link_online(struct ata_link *link);
+extern bool ata_link_offline(struct ata_link *link);
 #ifdef CONFIG_PM
 extern int ata_host_suspend(struct ata_host *host, pm_message_t mesg);
 extern void ata_host_resume(struct ata_host *host);
-- 
cgit v1.2.3-70-g09d2


From b1c72916abbdd0a55015c87358536ca0ebaf6735 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 31 Jul 2008 17:02:43 +0900
Subject: libata: implement slave_link

Explanation taken from the comment of ata_slave_link_init().

 In libata, a port contains links and a link contains devices.  There
 is single host link but if a PMP is attached to it, there can be
 multiple fan-out links.  On SATA, there's usually a single device
 connected to a link but PATA and SATA controllers emulating TF based
 interface can have two - master and slave.

 However, there are a few controllers which don't fit into this
 abstraction too well - SATA controllers which emulate TF interface
 with both master and slave devices but also have separate SCR
 register sets for each device.  These controllers need separate links
 for physical link handling (e.g. onlineness, link speed) but should
 be treated like a traditional M/S controller for everything else
 (e.g. command issue, softreset).

 slave_link is libata's way of handling this class of controllers
 without impacting core layer too much.  For anything other than
 physical link handling, the default host link is used for both master
 and slave.  For physical link handling, separate @ap->slave_link is
 used.  All dirty details are implemented inside libata core layer.
 From LLD's POV, the only difference is that prereset, hardreset and
 postreset are called once more for the slave link, so the reset
 sequence looks like the following.

 prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
 softreset(M) -> postreset(M) -> postreset(S)

 Note that softreset is called only for the master.  Softreset resets
 both M/S by definition, so SRST on master should handle both (the
 standard method will work just fine).

As slave_link excludes PMP support and only code paths which deal with
the attributes of physical link are affected, all the changes are
localized to libata.h, libata-core.c and libata-eh.c.

 * ata_is_host_link() updated so that slave_link is considered as host
   link too.

 * iterator extended to iterate over the slave_link when using the
   underbarred version.

 * force param handling updated such that devno 16 is mapped to the
   slave link/device.

 * ata_link_on/offline() updated to return the combined result from
   master and slave link.  ata_phys_link_on/offline() are the direct
   versions.

 * EH autopsy and report are performed separately for master slave
   links.  Reset is udpated to implement the above described reset
   sequence.

Except for reset update, most changes are minor, many of them just
modifying dev->link to ata_dev_phys_link(dev) or using phys online
test instead.

After this update, LLDs can take full advantage of per-dev SCR
registers by simply turning on slave link.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 drivers/ata/libata-core.c | 202 ++++++++++++++++++++++++++++++++++++++++------
 drivers/ata/libata-eh.c   | 142 ++++++++++++++++++++++++++------
 drivers/ata/libata.h      |   3 +
 include/linux/libata.h    |   8 +-
 4 files changed, 303 insertions(+), 52 deletions(-)

(limited to 'include/linux/libata.h')

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 71024e94c57..6eed58e35e1 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -179,19 +179,51 @@ struct ata_link *__ata_port_next_link(struct ata_port *ap,
 		return &ap->link;
 	}
 
-	/* we just iterated over the host link, what's next? */
-	if (ata_is_host_link(link)) {
-		if (!sata_pmp_attached(ap))
+	/* 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)
+				return ap->slave_link;
 			return NULL;
+		}
 		return ap->pmp_link;
 	}
 
+	/* slave_link excludes PMP */
+	if (unlikely(link == ap->slave_link))
+		return NULL;
+
 	/* iterate to the next PMP link */
 	if (++link < ap->pmp_link + ap->nr_pmp_links)
 		return link;
 	return NULL;
 }
 
+/**
+ *	ata_dev_phys_link - find physical link for a device
+ *	@dev: ATA device to look up physical link for
+ *
+ *	Look up physical link which @dev is attached to.  Note that
+ *	this is different from @dev->link only when @dev is on slave
+ *	link.  For all other cases, it's the same as @dev->link.
+ *
+ *	LOCKING:
+ *	Don't care.
+ *
+ *	RETURNS:
+ *	Pointer to the found physical link.
+ */
+struct ata_link *ata_dev_phys_link(struct ata_device *dev)
+{
+	struct ata_port *ap = dev->link->ap;
+
+	if (!ap->slave_link)
+		return dev->link;
+	if (!dev->devno)
+		return &ap->link;
+	return ap->slave_link;
+}
+
 /**
  *	ata_force_cbl - force cable type according to libata.force
  *	@ap: ATA port of interest
@@ -235,7 +267,8 @@ void ata_force_cbl(struct ata_port *ap)
  *	the host link and all fan-out ports connected via PMP.  If the
  *	device part is specified as 0 (e.g. 1.00:), it specifies the
  *	first fan-out link not the host link.  Device number 15 always
- *	points to the host link whether PMP is attached or not.
+ *	points to the host link whether PMP is attached or not.  If the
+ *	controller has slave link, device number 16 points to it.
  *
  *	LOCKING:
  *	EH context.
@@ -243,12 +276,11 @@ void ata_force_cbl(struct ata_port *ap)
 static void ata_force_link_limits(struct ata_link *link)
 {
 	bool did_spd = false;
-	int linkno, i;
+	int linkno = link->pmp;
+	int i;
 
 	if (ata_is_host_link(link))
-		linkno = 15;
-	else
-		linkno = link->pmp;
+		linkno += 15;
 
 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
 		const struct ata_force_ent *fe = &ata_force_tbl[i];
@@ -295,9 +327,9 @@ static void ata_force_xfermask(struct ata_device *dev)
 	int alt_devno = devno;
 	int i;
 
-	/* allow n.15 for the first device attached to host port */
-	if (ata_is_host_link(dev->link) && devno == 0)
-		alt_devno = 15;
+	/* allow n.15/16 for devices attached to host port */
+	if (ata_is_host_link(dev->link))
+		alt_devno += 15;
 
 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
 		const struct ata_force_ent *fe = &ata_force_tbl[i];
@@ -349,9 +381,9 @@ static void ata_force_horkage(struct ata_device *dev)
 	int alt_devno = devno;
 	int i;
 
-	/* allow n.15 for the first device attached to host port */
-	if (ata_is_host_link(dev->link) && devno == 0)
-		alt_devno = 15;
+	/* allow n.15/16 for devices attached to host port */
+	if (ata_is_host_link(dev->link))
+		alt_devno += 15;
 
 	for (i = 0; i < ata_force_tbl_size; i++) {
 		const struct ata_force_ent *fe = &ata_force_tbl[i];
@@ -2710,7 +2742,7 @@ static void sata_print_link_status(struct ata_link *link)
 		return;
 	sata_scr_read(link, SCR_CONTROL, &scontrol);
 
-	if (ata_link_online(link)) {
+	if (ata_phys_link_online(link)) {
 		tmp = (sstatus >> 4) & 0xf;
 		ata_link_printk(link, KERN_INFO,
 				"SATA link up %s (SStatus %X SControl %X)\n",
@@ -3401,6 +3433,12 @@ int ata_wait_ready(struct ata_link *link, unsigned long deadline,
 	unsigned long nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT);
 	int warned = 0;
 
+	/* Slave readiness can't be tested separately from master.  On
+	 * M/S emulation configuration, this function should be called
+	 * only on the master and it will handle both master and slave.
+	 */
+	WARN_ON(link == link->ap->slave_link);
+
 	if (time_after(nodev_deadline, deadline))
 		nodev_deadline = deadline;
 
@@ -3622,7 +3660,7 @@ int ata_std_prereset(struct ata_link *link, unsigned long deadline)
 	}
 
 	/* no point in trying softreset on offline link */
-	if (ata_link_offline(link))
+	if (ata_phys_link_offline(link))
 		ehc->i.action &= ~ATA_EH_SOFTRESET;
 
 	return 0;
@@ -3700,7 +3738,7 @@ int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
 	if (rc)
 		goto out;
 	/* if link is offline nothing more to do */
-	if (ata_link_offline(link))
+	if (ata_phys_link_offline(link))
 		goto out;
 
 	/* Link is online.  From this point, -ENODEV too is an error. */
@@ -4965,7 +5003,7 @@ int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
 }
 
 /**
- *	ata_link_online - test whether the given link is online
+ *	ata_phys_link_online - test whether the given link is online
  *	@link: ATA link to test
  *
  *	Test whether @link is online.  Note that this function returns
@@ -4978,7 +5016,7 @@ int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
  *	RETURNS:
  *	True if the port online status is available and online.
  */
-bool ata_link_online(struct ata_link *link)
+bool ata_phys_link_online(struct ata_link *link)
 {
 	u32 sstatus;
 
@@ -4989,7 +5027,7 @@ bool ata_link_online(struct ata_link *link)
 }
 
 /**
- *	ata_link_offline - test whether the given link is offline
+ *	ata_phys_link_offline - test whether the given link is offline
  *	@link: ATA link to test
  *
  *	Test whether @link is offline.  Note that this function
@@ -5002,7 +5040,7 @@ bool ata_link_online(struct ata_link *link)
  *	RETURNS:
  *	True if the port offline status is available and offline.
  */
-bool ata_link_offline(struct ata_link *link)
+bool ata_phys_link_offline(struct ata_link *link)
 {
 	u32 sstatus;
 
@@ -5012,6 +5050,58 @@ bool ata_link_offline(struct ata_link *link)
 	return false;
 }
 
+/**
+ *	ata_link_online - test whether the given link is online
+ *	@link: ATA link to test
+ *
+ *	Test whether @link is online.  This is identical to
+ *	ata_phys_link_online() when there's no slave link.  When
+ *	there's a slave link, this function should only be called on
+ *	the master link and will return true if any of M/S links is
+ *	online.
+ *
+ *	LOCKING:
+ *	None.
+ *
+ *	RETURNS:
+ *	True if the port online status is available and online.
+ */
+bool ata_link_online(struct ata_link *link)
+{
+	struct ata_link *slave = link->ap->slave_link;
+
+	WARN_ON(link == slave);	/* shouldn't be called on slave link */
+
+	return ata_phys_link_online(link) ||
+		(slave && ata_phys_link_online(slave));
+}
+
+/**
+ *	ata_link_offline - test whether the given link is offline
+ *	@link: ATA link to test
+ *
+ *	Test whether @link is offline.  This is identical to
+ *	ata_phys_link_offline() when there's no slave link.  When
+ *	there's a slave link, this function should only be called on
+ *	the master link and will return true if both M/S links are
+ *	offline.
+ *
+ *	LOCKING:
+ *	None.
+ *
+ *	RETURNS:
+ *	True if the port offline status is available and offline.
+ */
+bool ata_link_offline(struct ata_link *link)
+{
+	struct ata_link *slave = link->ap->slave_link;
+
+	WARN_ON(link == slave);	/* shouldn't be called on slave link */
+
+	return ata_phys_link_offline(link) &&
+		(!slave || ata_phys_link_offline(slave));
+}
+
 #ifdef CONFIG_PM
 static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
 			       unsigned int action, unsigned int ehi_flags,
@@ -5151,11 +5241,11 @@ int ata_port_start(struct ata_port *ap)
  */
 void ata_dev_init(struct ata_device *dev)
 {
-	struct ata_link *link = dev->link;
+	struct ata_link *link = ata_dev_phys_link(dev);
 	struct ata_port *ap = link->ap;
 	unsigned long flags;
 
-	/* SATA spd limit is bound to the first device */
+	/* SATA spd limit is bound to the attached device, reset together */
 	link->sata_spd_limit = link->hw_sata_spd_limit;
 	link->sata_spd = 0;
 
@@ -5318,6 +5408,7 @@ static void ata_host_release(struct device *gendev, void *res)
 			scsi_host_put(ap->scsi_host);
 
 		kfree(ap->pmp_link);
+		kfree(ap->slave_link);
 		kfree(ap);
 		host->ports[i] = NULL;
 	}
@@ -5438,6 +5529,68 @@ struct ata_host *ata_host_alloc_pinfo(struct device *dev,
 	return host;
 }
 
+/**
+ *	ata_slave_link_init - initialize slave link
+ *	@ap: port to initialize slave link for
+ *
+ *	Create and initialize slave link for @ap.  This enables slave
+ *	link handling on the port.
+ *
+ *	In libata, a port contains links and a link contains devices.
+ *	There is single host link but if a PMP is attached to it,
+ *	there can be multiple fan-out links.  On SATA, there's usually
+ *	a single device connected to a link but PATA and SATA
+ *	controllers emulating TF based interface can have two - master
+ *	and slave.
+ *
+ *	However, there are a few controllers which don't fit into this
+ *	abstraction too well - SATA controllers which emulate TF
+ *	interface with both master and slave devices but also have
+ *	separate SCR register sets for each device.  These controllers
+ *	need separate links for physical link handling
+ *	(e.g. onlineness, link speed) but should be treated like a
+ *	traditional M/S controller for everything else (e.g. command
+ *	issue, softreset).
+ *
+ *	slave_link is libata's way of handling this class of
+ *	controllers without impacting core layer too much.  For
+ *	anything other than physical link handling, the default host
+ *	link is used for both master and slave.  For physical link
+ *	handling, separate @ap->slave_link is used.  All dirty details
+ *	are implemented inside libata core layer.  From LLD's POV, the
+ *	only difference is that prereset, hardreset and postreset are
+ *	called once more for the slave link, so the reset sequence
+ *	looks like the following.
+ *
+ *	prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
+ *	softreset(M) -> postreset(M) -> postreset(S)
+ *
+ *	Note that softreset is called only for the master.  Softreset
+ *	resets both M/S by definition, so SRST on master should handle
+ *	both (the standard method will work just fine).
+ *
+ *	LOCKING:
+ *	Should be called before host is registered.
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int ata_slave_link_init(struct ata_port *ap)
+{
+	struct ata_link *link;
+
+	WARN_ON(ap->slave_link);
+	WARN_ON(ap->flags & ATA_FLAG_PMP);
+
+	link = kzalloc(sizeof(*link), GFP_KERNEL);
+	if (!link)
+		return -ENOMEM;
+
+	ata_link_init(ap, link, 1);
+	ap->slave_link = link;
+	return 0;
+}
+
 static void ata_host_stop(struct device *gendev, void *res)
 {
 	struct ata_host *host = dev_get_drvdata(gendev);
@@ -5664,6 +5817,8 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 
 		/* init sata_spd_limit to the current value */
 		sata_link_init_spd(&ap->link);
+		if (ap->slave_link)
+			sata_link_init_spd(ap->slave_link);
 
 		/* print per-port info to dmesg */
 		xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
@@ -6289,6 +6444,7 @@ EXPORT_SYMBOL_GPL(ata_std_bios_param);
 EXPORT_SYMBOL_GPL(ata_host_init);
 EXPORT_SYMBOL_GPL(ata_host_alloc);
 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
+EXPORT_SYMBOL_GPL(ata_slave_link_init);
 EXPORT_SYMBOL_GPL(ata_host_start);
 EXPORT_SYMBOL_GPL(ata_host_register);
 EXPORT_SYMBOL_GPL(ata_host_activate);
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index c1db2f234d2..99037a4860d 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1756,7 +1756,7 @@ static unsigned int ata_eh_speed_down_verdict(struct ata_device *dev)
 static unsigned int ata_eh_speed_down(struct ata_device *dev,
 				unsigned int eflags, unsigned int err_mask)
 {
-	struct ata_link *link = dev->link;
+	struct ata_link *link = ata_dev_phys_link(dev);
 	int xfer_ok = 0;
 	unsigned int verdict;
 	unsigned int action = 0;
@@ -1880,7 +1880,8 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
 
-		if (!(qc->flags & ATA_QCFLAG_FAILED) || qc->dev->link != link)
+		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
+		    ata_dev_phys_link(qc->dev) != link)
 			continue;
 
 		/* inherit upper level err_mask */
@@ -1967,6 +1968,23 @@ void ata_eh_autopsy(struct ata_port *ap)
 	ata_port_for_each_link(link, ap)
 		ata_eh_link_autopsy(link);
 
+	/* Handle the frigging slave link.  Autopsy is done similarly
+	 * but actions and flags are transferred over to the master
+	 * link and handled from there.
+	 */
+	if (ap->slave_link) {
+		struct ata_eh_context *mehc = &ap->link.eh_context;
+		struct ata_eh_context *sehc = &ap->slave_link->eh_context;
+
+		ata_eh_link_autopsy(ap->slave_link);
+
+		ata_eh_about_to_do(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
+		mehc->i.action		|= sehc->i.action;
+		mehc->i.dev_action[1]	|= sehc->i.dev_action[1];
+		mehc->i.flags		|= sehc->i.flags;
+		ata_eh_done(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
+	}
+
 	/* Autopsy of fanout ports can affect host link autopsy.
 	 * Perform host link autopsy last.
 	 */
@@ -2001,7 +2019,8 @@ static void ata_eh_link_report(struct ata_link *link)
 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
 
-		if (!(qc->flags & ATA_QCFLAG_FAILED) || qc->dev->link != link ||
+		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
+		    ata_dev_phys_link(qc->dev) != link ||
 		    ((qc->flags & ATA_QCFLAG_QUIET) &&
 		     qc->err_mask == AC_ERR_DEV))
 			continue;
@@ -2068,7 +2087,7 @@ static void ata_eh_link_report(struct ata_link *link)
 		char cdb_buf[70] = "";
 
 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
-		    qc->dev->link != link || !qc->err_mask)
+		    ata_dev_phys_link(qc->dev) != link || !qc->err_mask)
 			continue;
 
 		if (qc->dma_dir != DMA_NONE) {
@@ -2160,12 +2179,14 @@ void ata_eh_report(struct ata_port *ap)
 }
 
 static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
-			unsigned int *classes, unsigned long deadline)
+			unsigned int *classes, unsigned long deadline,
+			bool clear_classes)
 {
 	struct ata_device *dev;
 
-	ata_link_for_each_dev(dev, link)
-		classes[dev->devno] = ATA_DEV_UNKNOWN;
+	if (clear_classes)
+		ata_link_for_each_dev(dev, link)
+			classes[dev->devno] = ATA_DEV_UNKNOWN;
 
 	return reset(link, classes, deadline);
 }
@@ -2187,17 +2208,20 @@ int ata_eh_reset(struct ata_link *link, int classify,
 		 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
 	struct ata_port *ap = link->ap;
+	struct ata_link *slave = ap->slave_link;
 	struct ata_eh_context *ehc = &link->eh_context;
+	struct ata_eh_context *sehc = &slave->eh_context;
 	unsigned int *classes = ehc->classes;
 	unsigned int lflags = link->flags;
 	int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
 	int max_tries = 0, try = 0;
+	struct ata_link *failed_link;
 	struct ata_device *dev;
 	unsigned long deadline, now;
 	ata_reset_fn_t reset;
 	unsigned long flags;
 	u32 sstatus;
-	int nr_known, rc;
+	int nr_unknown, rc;
 
 	/*
 	 * Prepare to reset
@@ -2252,8 +2276,30 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	}
 
 	if (prereset) {
-		rc = prereset(link,
-			      ata_deadline(jiffies, ATA_EH_PRERESET_TIMEOUT));
+		unsigned long deadline = ata_deadline(jiffies,
+						      ATA_EH_PRERESET_TIMEOUT);
+
+		if (slave) {
+			sehc->i.action &= ~ATA_EH_RESET;
+			sehc->i.action |= ehc->i.action;
+		}
+
+		rc = prereset(link, deadline);
+
+		/* If present, do prereset on slave link too.  Reset
+		 * is skipped iff both master and slave links report
+		 * -ENOENT or clear ATA_EH_RESET.
+		 */
+		if (slave && (rc == 0 || rc == -ENOENT)) {
+			int tmp;
+
+			tmp = prereset(slave, deadline);
+			if (tmp != -ENOENT)
+				rc = tmp;
+
+			ehc->i.action |= sehc->i.action;
+		}
+
 		if (rc) {
 			if (rc == -ENOENT) {
 				ata_link_printk(link, KERN_DEBUG,
@@ -2302,25 +2348,51 @@ int ata_eh_reset(struct ata_link *link, int classify,
 		else
 			ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
 
-		rc = ata_do_reset(link, reset, classes, deadline);
-		if (rc && rc != -EAGAIN)
+		rc = ata_do_reset(link, reset, classes, deadline, true);
+		if (rc && rc != -EAGAIN) {
+			failed_link = link;
 			goto fail;
+		}
+
+		/* hardreset slave link if existent */
+		if (slave && reset == hardreset) {
+			int tmp;
+
+			if (verbose)
+				ata_link_printk(slave, KERN_INFO,
+						"hard resetting link\n");
 
+			ata_eh_about_to_do(slave, NULL, ATA_EH_RESET);
+			tmp = ata_do_reset(slave, reset, classes, deadline,
+					   false);
+			switch (tmp) {
+			case -EAGAIN:
+				rc = -EAGAIN;
+			case 0:
+				break;
+			default:
+				failed_link = slave;
+				rc = tmp;
+				goto fail;
+			}
+		}
+
+		/* perform follow-up SRST if necessary */
 		if (reset == hardreset &&
 		    ata_eh_followup_srst_needed(link, rc, classes)) {
-			/* okay, let's do follow-up softreset */
 			reset = softreset;
 
 			if (!reset) {
 				ata_link_printk(link, KERN_ERR,
 						"follow-up softreset required "
 						"but no softreset avaliable\n");
+				failed_link = link;
 				rc = -EINVAL;
 				goto fail;
 			}
 
 			ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
-			rc = ata_do_reset(link, reset, classes, deadline);
+			rc = ata_do_reset(link, reset, classes, deadline, true);
 		}
 	} else {
 		if (verbose)
@@ -2341,7 +2413,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 		dev->pio_mode = XFER_PIO_0;
 		dev->flags &= ~ATA_DFLAG_SLEEPING;
 
-		if (ata_link_offline(link))
+		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
 			continue;
 
 		/* apply class override */
@@ -2354,6 +2426,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	/* record current link speed */
 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
 		link->sata_spd = (sstatus >> 4) & 0xf;
+	if (slave && sata_scr_read(slave, SCR_STATUS, &sstatus) == 0)
+		slave->sata_spd = (sstatus >> 4) & 0xf;
 
 	/* thaw the port */
 	if (ata_is_host_link(link))
@@ -2366,12 +2440,17 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	 * reset and here.  This race is mediated by cross checking
 	 * link onlineness and classification result later.
 	 */
-	if (postreset)
+	if (postreset) {
 		postreset(link, classes);
+		if (slave)
+			postreset(slave, classes);
+	}
 
 	/* clear cached SError */
 	spin_lock_irqsave(link->ap->lock, flags);
 	link->eh_info.serror = 0;
+	if (slave)
+		slave->eh_info.serror = 0;
 	spin_unlock_irqrestore(link->ap->lock, flags);
 
 	/* Make sure onlineness and classification result correspond.
@@ -2381,19 +2460,21 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	 * link onlineness and classification result, those conditions
 	 * can be reliably detected and retried.
 	 */
-	nr_known = 0;
+	nr_unknown = 0;
 	ata_link_for_each_dev(dev, link) {
 		/* convert all ATA_DEV_UNKNOWN to ATA_DEV_NONE */
-		if (classes[dev->devno] == ATA_DEV_UNKNOWN)
+		if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
 			classes[dev->devno] = ATA_DEV_NONE;
-		else
-			nr_known++;
+			if (ata_phys_link_online(ata_dev_phys_link(dev)))
+				nr_unknown++;
+		}
 	}
 
-	if (classify && !nr_known && ata_link_online(link)) {
+	if (classify && nr_unknown) {
 		if (try < max_tries) {
 			ata_link_printk(link, KERN_WARNING, "link online but "
 				       "device misclassified, retrying\n");
+			failed_link = link;
 			rc = -EAGAIN;
 			goto fail;
 		}
@@ -2404,6 +2485,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
 
 	/* reset successful, schedule revalidation */
 	ata_eh_done(link, NULL, ATA_EH_RESET);
+	if (slave)
+		ata_eh_done(slave, NULL, ATA_EH_RESET);
 	ehc->last_reset = jiffies;
 	ehc->i.action |= ATA_EH_REVALIDATE;
 
@@ -2411,6 +2494,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
  out:
 	/* clear hotplug flag */
 	ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
+	if (slave)
+		sehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
 
 	spin_lock_irqsave(ap->lock, flags);
 	ap->pflags &= ~ATA_PFLAG_RESETTING;
@@ -2431,7 +2516,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	if (time_before(now, deadline)) {
 		unsigned long delta = deadline - now;
 
-		ata_link_printk(link, KERN_WARNING,
+		ata_link_printk(failed_link, KERN_WARNING,
 			"reset failed (errno=%d), retrying in %u secs\n",
 			rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000));
 
@@ -2439,8 +2524,13 @@ int ata_eh_reset(struct ata_link *link, int classify,
 			delta = schedule_timeout_uninterruptible(delta);
 	}
 
-	if (rc == -EPIPE || try == max_tries - 1)
+	if (try == max_tries - 1) {
 		sata_down_spd_limit(link);
+		if (slave)
+			sata_down_spd_limit(slave);
+	} else if (rc == -EPIPE)
+		sata_down_spd_limit(failed_link);
+
 	if (hardreset)
 		reset = hardreset;
 	goto retry;
@@ -2472,7 +2562,7 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
 		if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
 			WARN_ON(dev->class == ATA_DEV_PMP);
 
-			if (ata_link_offline(link)) {
+			if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
 				rc = -EIO;
 				goto err;
 			}
@@ -2697,7 +2787,7 @@ static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
 			/* This is the last chance, better to slow
 			 * down than lose it.
 			 */
-			sata_down_spd_limit(dev->link);
+			sata_down_spd_limit(ata_dev_phys_link(dev));
 			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
 		}
 	}
@@ -2707,7 +2797,7 @@ static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
 		ata_dev_disable(dev);
 
 		/* detach if offline */
-		if (ata_link_offline(dev->link))
+		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
 			ata_eh_detach_dev(dev);
 
 		/* schedule probe if necessary */
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index ade5c75b614..e96de96e302 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -70,6 +70,7 @@ extern int atapi_passthru16;
 extern int libata_fua;
 extern int libata_noacpi;
 extern int libata_allow_tpm;
+extern struct ata_link *ata_dev_phys_link(struct ata_device *dev);
 extern void ata_force_cbl(struct ata_port *ap);
 extern u64 ata_tf_to_lba(const struct ata_taskfile *tf);
 extern u64 ata_tf_to_lba48(const struct ata_taskfile *tf);
@@ -107,6 +108,8 @@ extern void ata_qc_issue(struct ata_queued_cmd *qc);
 extern void __ata_qc_complete(struct ata_queued_cmd *qc);
 extern int atapi_check_dma(struct ata_queued_cmd *qc);
 extern void swap_buf_le16(u16 *buf, unsigned int buf_words);
+extern bool ata_phys_link_online(struct ata_link *link);
+extern bool ata_phys_link_offline(struct ata_link *link);
 extern void ata_dev_init(struct ata_device *dev);
 extern void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp);
 extern int sata_link_init_spd(struct ata_link *link);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 0c7e6f3c28e..244ff601559 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -690,7 +690,8 @@ struct ata_port {
 	unsigned int		qc_active;
 	int			nr_active_links; /* #links with active qcs */
 
-	struct ata_link		link;	/* host default link */
+	struct ata_link		link;		/* host default link */
+	struct ata_link		*slave_link;	/* see ata_slave_link_init() */
 
 	int			nr_pmp_links;	/* nr of available PMP links */
 	struct ata_link		*pmp_link;	/* array of PMP links */
@@ -897,6 +898,7 @@ extern void ata_port_disable(struct ata_port *);
 extern struct ata_host *ata_host_alloc(struct device *dev, int max_ports);
 extern struct ata_host *ata_host_alloc_pinfo(struct device *dev,
 			const struct ata_port_info * const * ppi, int n_ports);
+extern int ata_slave_link_init(struct ata_port *ap);
 extern int ata_host_start(struct ata_host *host);
 extern int ata_host_register(struct ata_host *host,
 			     struct scsi_host_template *sht);
@@ -1136,7 +1138,7 @@ static inline bool sata_pmp_attached(struct ata_port *ap)
 
 static inline int ata_is_host_link(const struct ata_link *link)
 {
-	return link == &link->ap->link;
+	return link == &link->ap->link || link == link->ap->slave_link;
 }
 #else /* CONFIG_SATA_PMP */
 static inline bool sata_pmp_supported(struct ata_port *ap)
@@ -1169,7 +1171,7 @@ static inline int sata_srst_pmp(struct ata_link *link)
 	printk("%sata%u: "fmt, lv, (ap)->print_id , ##args)
 
 #define ata_link_printk(link, lv, fmt, args...) do { \
-	if (sata_pmp_attached((link)->ap)) \
+	if (sata_pmp_attached((link)->ap) || (link)->ap->slave_link)	\
 		printk("%sata%u.%02u: "fmt, lv, (link)->ap->print_id,	\
 		       (link)->pmp , ##args); \
 	else \
-- 
cgit v1.2.3-70-g09d2


From 45fabbb77bd95adff7a80bde1c7a0ace1075fde6 Mon Sep 17 00:00:00 2001
From: Elias Oltmanns <eo@nebensachen.de>
Date: Sun, 21 Sep 2008 11:54:08 +0200
Subject: libata: Implement disk shock protection support

On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD
FEATURE as specified in ATA-7 is issued to the device and processing of
the request queue is stopped thereafter until the specified timeout
expires or user space asks to resume normal operation. This is supposed
to prevent the heads of a hard drive from accidentally crashing onto the
platter when a heavy shock is anticipated (like a falling laptop
expected to hit the floor). In fact, the whole port stops processing
commands until the timeout has expired in order to avoid any resets due
to failed commands on another device.

Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 drivers/ata/ahci.c        |   1 +
 drivers/ata/libata-core.c |   1 +
 drivers/ata/libata-eh.c   | 126 +++++++++++++++++++++++++++++++++++++++++++++-
 drivers/ata/libata-scsi.c | 108 +++++++++++++++++++++++++++++++++++++++
 include/linux/libata.h    |  13 ++++-
 5 files changed, 246 insertions(+), 3 deletions(-)

(limited to 'include/linux/libata.h')

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 6acea41eb7c..aeadd00411a 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -316,6 +316,7 @@ static struct device_attribute *ahci_shost_attrs[] = {
 
 static struct device_attribute *ahci_sdev_attrs[] = {
 	&dev_attr_sw_activity,
+	&dev_attr_unload_heads,
 	NULL
 };
 
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 6eed58e35e1..1ee9499bd34 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5378,6 +5378,7 @@ struct ata_port *ata_port_alloc(struct ata_host *host)
 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
 	INIT_LIST_HEAD(&ap->eh_done_q);
 	init_waitqueue_head(&ap->eh_wait_q);
+	init_completion(&ap->park_req_pending);
 	init_timer_deferrable(&ap->fastdrain_timer);
 	ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
 	ap->fastdrain_timer.data = (unsigned long)ap;
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 99037a4860d..33ac5ea4f53 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2536,6 +2536,80 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	goto retry;
 }
 
+static inline void ata_eh_pull_park_action(struct ata_port *ap)
+{
+	struct ata_link *link;
+	struct ata_device *dev;
+	unsigned long flags;
+
+	/*
+	 * This function can be thought of as an extended version of
+	 * ata_eh_about_to_do() specially crafted to accommodate the
+	 * requirements of ATA_EH_PARK handling. Since the EH thread
+	 * does not leave the do {} while () loop in ata_eh_recover as
+	 * long as the timeout for a park request to *one* device on
+	 * the port has not expired, and since we still want to pick
+	 * up park requests to other devices on the same port or
+	 * timeout updates for the same device, we have to pull
+	 * ATA_EH_PARK actions from eh_info into eh_context.i
+	 * ourselves at the beginning of each pass over the loop.
+	 *
+	 * Additionally, all write accesses to &ap->park_req_pending
+	 * through INIT_COMPLETION() (see below) or complete_all()
+	 * (see ata_scsi_park_store()) are protected by the host lock.
+	 * As a result we have that park_req_pending.done is zero on
+	 * exit from this function, i.e. when ATA_EH_PARK actions for
+	 * *all* devices on port ap have been pulled into the
+	 * respective eh_context structs. If, and only if,
+	 * park_req_pending.done is non-zero by the time we reach
+	 * wait_for_completion_timeout(), another ATA_EH_PARK action
+	 * has been scheduled for at least one of the devices on port
+	 * ap and we have to cycle over the do {} while () loop in
+	 * ata_eh_recover() again.
+	 */
+
+	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) {
+			struct ata_eh_info *ehi = &link->eh_info;
+
+			link->eh_context.i.dev_action[dev->devno] |=
+				ehi->dev_action[dev->devno] & ATA_EH_PARK;
+			ata_eh_clear_action(link, dev, ehi, ATA_EH_PARK);
+		}
+	}
+	spin_unlock_irqrestore(ap->lock, flags);
+}
+
+static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
+{
+	struct ata_eh_context *ehc = &dev->link->eh_context;
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+
+	ata_tf_init(dev, &tf);
+	if (park) {
+		ehc->unloaded_mask |= 1 << dev->devno;
+		tf.command = ATA_CMD_IDLEIMMEDIATE;
+		tf.feature = 0x44;
+		tf.lbal = 0x4c;
+		tf.lbam = 0x4e;
+		tf.lbah = 0x55;
+	} else {
+		ehc->unloaded_mask &= ~(1 << dev->devno);
+		tf.command = ATA_CMD_CHK_POWER;
+	}
+
+	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+	tf.protocol |= ATA_PROT_NODATA;
+	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
+	if (park && (err_mask || tf.lbal != 0xc4)) {
+		ata_dev_printk(dev, KERN_ERR, "head unload failed!\n");
+		ehc->unloaded_mask &= ~(1 << dev->devno);
+	}
+}
+
 static int ata_eh_revalidate_and_attach(struct ata_link *link,
 					struct ata_device **r_failed_dev)
 {
@@ -2845,7 +2919,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 	struct ata_device *dev;
 	int nr_failed_devs;
 	int rc;
-	unsigned long flags;
+	unsigned long flags, deadline;
 
 	DPRINTK("ENTER\n");
 
@@ -2919,6 +2993,56 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		}
 	}
 
+	do {
+		unsigned long now;
+
+		/*
+		 * clears ATA_EH_PARK in eh_info and resets
+		 * ap->park_req_pending
+		 */
+		ata_eh_pull_park_action(ap);
+
+		deadline = jiffies;
+		ata_port_for_each_link(link, ap) {
+			ata_link_for_each_dev(dev, link) {
+				struct ata_eh_context *ehc = &link->eh_context;
+				unsigned long tmp;
+
+				if (dev->class != ATA_DEV_ATA)
+					continue;
+				if (!(ehc->i.dev_action[dev->devno] &
+				      ATA_EH_PARK))
+					continue;
+				tmp = dev->unpark_deadline;
+				if (time_before(deadline, tmp))
+					deadline = tmp;
+				else if (time_before_eq(tmp, jiffies))
+					continue;
+				if (ehc->unloaded_mask & (1 << dev->devno))
+					continue;
+
+				ata_eh_park_issue_cmd(dev, 1);
+			}
+		}
+
+		now = jiffies;
+		if (time_before_eq(deadline, now))
+			break;
+
+		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) {
+			if (!(link->eh_context.unloaded_mask &
+			      (1 << dev->devno)))
+				continue;
+
+			ata_eh_park_issue_cmd(dev, 0);
+			ata_eh_done(link, dev, ATA_EH_PARK);
+		}
+	}
+
 	/* the rest */
 	ata_port_for_each_link(link, ap) {
 		struct ata_eh_context *ehc = &link->eh_context;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b9d3ba423cb..fccd5e496c6 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -183,6 +183,105 @@ DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
 		ata_scsi_lpm_show, ata_scsi_lpm_put);
 EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
 
+static ssize_t ata_scsi_park_show(struct device *device,
+				  struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(device);
+	struct ata_port *ap;
+	struct ata_link *link;
+	struct ata_device *dev;
+	unsigned long flags;
+	unsigned int uninitialized_var(msecs);
+	int rc = 0;
+
+	ap = ata_shost_to_port(sdev->host);
+
+	spin_lock_irqsave(ap->lock, flags);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (!dev) {
+		rc = -ENODEV;
+		goto unlock;
+	}
+	if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
+		rc = -EOPNOTSUPP;
+		goto unlock;
+	}
+
+	link = dev->link;
+	if (ap->pflags & ATA_PFLAG_EH_IN_PROGRESS &&
+	    link->eh_context.unloaded_mask & (1 << dev->devno) &&
+	    time_after(dev->unpark_deadline, jiffies))
+		msecs = jiffies_to_msecs(dev->unpark_deadline - jiffies);
+	else
+		msecs = 0;
+
+unlock:
+	spin_unlock_irq(ap->lock);
+
+	return rc ? rc : snprintf(buf, 20, "%u\n", msecs);
+}
+
+static ssize_t ata_scsi_park_store(struct device *device,
+				   struct device_attribute *attr,
+				   const char *buf, size_t len)
+{
+	struct scsi_device *sdev = to_scsi_device(device);
+	struct ata_port *ap;
+	struct ata_device *dev;
+	long int input;
+	unsigned long flags;
+	int rc;
+
+	rc = strict_strtol(buf, 10, &input);
+	if (rc || input < -2)
+		return -EINVAL;
+	if (input > ATA_TMOUT_MAX_PARK) {
+		rc = -EOVERFLOW;
+		input = ATA_TMOUT_MAX_PARK;
+	}
+
+	ap = ata_shost_to_port(sdev->host);
+
+	spin_lock_irqsave(ap->lock, flags);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (unlikely(!dev)) {
+		rc = -ENODEV;
+		goto unlock;
+	}
+	if (dev->class != ATA_DEV_ATA) {
+		rc = -EOPNOTSUPP;
+		goto unlock;
+	}
+
+	if (input >= 0) {
+		if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
+			rc = -EOPNOTSUPP;
+			goto unlock;
+		}
+
+		dev->unpark_deadline = ata_deadline(jiffies, input);
+		dev->link->eh_info.dev_action[dev->devno] |= ATA_EH_PARK;
+		ata_port_schedule_eh(ap);
+		complete(&ap->park_req_pending);
+	} else {
+		switch (input) {
+		case -1:
+			dev->flags &= ~ATA_DFLAG_NO_UNLOAD;
+			break;
+		case -2:
+			dev->flags |= ATA_DFLAG_NO_UNLOAD;
+			break;
+		}
+	}
+unlock:
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	return rc ? rc : len;
+}
+DEVICE_ATTR(unload_heads, S_IRUGO | S_IWUSR,
+	    ata_scsi_park_show, ata_scsi_park_store);
+EXPORT_SYMBOL_GPL(dev_attr_unload_heads);
+
 static void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
 {
 	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
@@ -269,6 +368,12 @@ DEVICE_ATTR(sw_activity, S_IWUGO | S_IRUGO, ata_scsi_activity_show,
 			ata_scsi_activity_store);
 EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
 
+struct device_attribute *ata_common_sdev_attrs[] = {
+	&dev_attr_unload_heads,
+	NULL
+};
+EXPORT_SYMBOL_GPL(ata_common_sdev_attrs);
+
 static void ata_scsi_invalid_field(struct scsi_cmnd *cmd,
 				   void (*done)(struct scsi_cmnd *))
 {
@@ -954,6 +1059,9 @@ static int atapi_drain_needed(struct request *rq)
 static int ata_scsi_dev_config(struct scsi_device *sdev,
 			       struct ata_device *dev)
 {
+	if (!ata_id_has_unload(dev->id))
+		dev->flags |= ATA_DFLAG_NO_UNLOAD;
+
 	/* configure max sectors */
 	blk_queue_max_sectors(sdev->request_queue, dev->max_sectors);
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 244ff601559..1f44cfb847e 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -146,6 +146,7 @@ enum {
 	ATA_DFLAG_SPUNDOWN	= (1 << 14), /* XXX: for spindown_compat */
 	ATA_DFLAG_SLEEPING	= (1 << 15), /* device is sleeping */
 	ATA_DFLAG_DUBIOUS_XFER	= (1 << 16), /* data transfer not verified */
+	ATA_DFLAG_NO_UNLOAD	= (1 << 17), /* device doesn't support unload */
 	ATA_DFLAG_INIT_MASK	= (1 << 24) - 1,
 
 	ATA_DFLAG_DETACH	= (1 << 24),
@@ -244,6 +245,7 @@ enum {
 	ATA_TMOUT_BOOT		= 30000,	/* heuristic */
 	ATA_TMOUT_BOOT_QUICK	=  7000,	/* heuristic */
 	ATA_TMOUT_INTERNAL_QUICK = 5000,
+	ATA_TMOUT_MAX_PARK	= 30000,
 
 	/* FIXME: GoVault needs 2s but we can't afford that without
 	 * parallel probing.  800ms is enough for iVDR disk
@@ -319,8 +321,9 @@ enum {
 	ATA_EH_RESET		= ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
 	ATA_EH_ENABLE_LINK	= (1 << 3),
 	ATA_EH_LPM		= (1 << 4),  /* link power management action */
+	ATA_EH_PARK		= (1 << 5), /* unload heads and stop I/O */
 
-	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE,
+	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE | ATA_EH_PARK,
 	ATA_EH_ALL_ACTIONS	= ATA_EH_REVALIDATE | ATA_EH_RESET |
 				  ATA_EH_ENABLE_LINK | ATA_EH_LPM,
 
@@ -454,6 +457,7 @@ enum link_pm {
 	MEDIUM_POWER,
 };
 extern struct device_attribute dev_attr_link_power_management_policy;
+extern struct device_attribute dev_attr_unload_heads;
 extern struct device_attribute dev_attr_em_message_type;
 extern struct device_attribute dev_attr_em_message;
 extern struct device_attribute dev_attr_sw_activity;
@@ -566,6 +570,7 @@ struct ata_device {
 	/* n_sector is used as CLEAR_OFFSET, read comment above CLEAR_OFFSET */
 	u64			n_sectors;	/* size of device, if ATA */
 	unsigned int		class;		/* ATA_DEV_xxx */
+	unsigned long		unpark_deadline;
 
 	u8			pio_mode;
 	u8			dma_mode;
@@ -623,6 +628,7 @@ struct ata_eh_context {
 					       [ATA_EH_CMD_TIMEOUT_TABLE_SIZE];
 	unsigned int		classes[ATA_MAX_DEVICES];
 	unsigned int		did_probe_mask;
+	unsigned int		unloaded_mask;
 	unsigned int		saved_ncq_enabled;
 	u8			saved_xfer_mode[ATA_MAX_DEVICES];
 	/* timestamp for the last reset attempt or success */
@@ -712,6 +718,7 @@ struct ata_port {
 	struct list_head	eh_done_q;
 	wait_queue_head_t	eh_wait_q;
 	int			eh_tries;
+	struct completion	park_req_pending;
 
 	pm_message_t		pm_mesg;
 	int			*pm_result;
@@ -1102,6 +1109,7 @@ extern void ata_std_error_handler(struct ata_port *ap);
  */
 extern const struct ata_port_operations ata_base_port_ops;
 extern const struct ata_port_operations sata_port_ops;
+extern struct device_attribute *ata_common_sdev_attrs[];
 
 #define ATA_BASE_SHT(drv_name)					\
 	.module			= THIS_MODULE,			\
@@ -1116,7 +1124,8 @@ extern const struct ata_port_operations sata_port_ops;
 	.proc_name		= drv_name,			\
 	.slave_configure	= ata_scsi_slave_config,	\
 	.slave_destroy		= ata_scsi_slave_destroy,	\
-	.bios_param		= ata_std_bios_param
+	.bios_param		= ata_std_bios_param,		\
+	.sdev_attrs		= ata_common_sdev_attrs
 
 #define ATA_NCQ_SHT(drv_name)					\
 	ATA_BASE_SHT(drv_name),					\
-- 
cgit v1.2.3-70-g09d2


From 6866e7bc83f13a1bc6de59099930e9db1ab0042f Mon Sep 17 00:00:00 2001
From: Richard Kennedy <richard@rsk.demon.co.uk>
Date: Mon, 22 Sep 2008 14:47:13 -0700
Subject: libata: reorder ata_device to remove 8 bytes of padding on 64 bits

reduce size by 8 bytes from 1160 to 1152 allowing it to fit in 1 fewer
cachelines.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 include/linux/libata.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'include/linux/libata.h')

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 1f44cfb847e..947cf84e555 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -560,8 +560,8 @@ struct ata_ering {
 struct ata_device {
 	struct ata_link		*link;
 	unsigned int		devno;		/* 0 or 1 */
-	unsigned long		flags;		/* ATA_DFLAG_xxx */
 	unsigned int		horkage;	/* List of broken features */
+	unsigned long		flags;		/* ATA_DFLAG_xxx */
 	struct scsi_device	*sdev;		/* attached SCSI device */
 #ifdef CONFIG_ATA_ACPI
 	acpi_handle		acpi_handle;
-- 
cgit v1.2.3-70-g09d2