[PATCH 06/12] libata-pmp-prep: implement qc_defer helpers

[PATCH 06/12] libata-pmp-prep: implement qc_defer helpers

[Tejun Heo]

Implement ap->nr_active_links (the number of links with active qcs),
ap->excl_link (pointer to link which can be used by ->qc_defer and is
cleared when a qc with ATA_QCFLAG_CLEAR_EXCL completes), and
ata_link_active().

These can be used by ->qc_defer() to implement proper command
exclusion.  This set of helpers seem enough for both sil24 (ATAPI
exclusion needed) and cmd-switching PMP.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-core.c |   22 ++++++++++++++++++++--
 drivers/ata/libata-eh.c   |    5 +++++
 include/linux/libata.h    |    8 ++++++++
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index fb5d7e7..17b1734 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1381,6 +1381,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	struct ata_queued_cmd *qc;
 	unsigned int tag, preempted_tag;
 	u32 preempted_sactive, preempted_qc_active;
+	int preempted_nr_active_links;
 	DECLARE_COMPLETION_ONSTACK(wait);
 	unsigned long flags;
 	unsigned int err_mask;
@@ -1419,9 +1420,11 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	preempted_tag = link->active_tag;
 	preempted_sactive = link->sactive;
 	preempted_qc_active = ap->qc_active;
+	preempted_nr_active_links = ap->nr_active_links;
 	link->active_tag = ATA_TAG_POISON;
 	link->sactive = 0;
 	ap->qc_active = 0;
+	ap->nr_active_links = 0;
 
 	/* prepare & issue qc */
 	qc->tf = *tf;
@@ -1500,6 +1503,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	link->active_tag = preempted_tag;
 	link->sactive = preempted_sactive;
 	ap->qc_active = preempted_qc_active;
+	ap->nr_active_links = preempted_nr_active_links;
 
 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
 	 * Until those drivers are fixed, we detect the condition
@@ -5208,10 +5212,19 @@ void __ata_qc_complete(struct ata_queued_cmd *qc)
 		ata_sg_clean(qc);
 
 	/* command should be marked inactive atomically with qc completion */
-	if (qc->tf.protocol == ATA_PROT_NCQ)
+	if (qc->tf.protocol == ATA_PROT_NCQ) {
 		link->sactive &= ~(1 << qc->tag);
-	else
+		if (!link->sactive)
+			ap->nr_active_links--;
+	} else {
 		link->active_tag = ATA_TAG_POISON;
+		ap->nr_active_links--;
+	}
+
+	/* clear exclusive status */
+	if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
+		     ap->excl_link == link))
+		ap->excl_link = NULL;
 
 	/* atapi: mark qc as inactive to prevent the interrupt handler
 	 * from completing the command twice later, before the error handler
@@ -5390,9 +5403,14 @@ void ata_qc_issue(struct ata_queued_cmd *qc)
 
 	if (qc->tf.protocol == ATA_PROT_NCQ) {
 		WARN_ON(link->sactive & (1 << qc->tag));
+
+		if (!link->sactive)
+			ap->nr_active_links++;
 		link->sactive |= 1 << qc->tag;
 	} else {
 		WARN_ON(link->sactive);
+
+		ap->nr_active_links++;
 		link->active_tag = qc->tag;
 	}
 
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index ec0b90b..3779067 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -316,6 +316,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 
 		ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
 		ap->pflags &= ~ATA_PFLAG_EH_PENDING;
+		ap->excl_link = NULL;	/* don't maintain exclusion over EH */
 
 		spin_unlock_irqrestore(ap->lock, flags);
 
@@ -2336,6 +2337,10 @@ void ata_eh_finish(struct ata_port *ap)
 			}
 		}
 	}
+
+	/* make sure nr_active_links is zero after EH */
+	WARN_ON(ap->nr_active_links);
+	ap->nr_active_links = 0;
 }
 
 /**
diff --git a/include/linux/libata.h b/include/linux/libata.h
index fa332e0..349180a 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -215,6 +215,7 @@ enum {
 	ATA_QCFLAG_DMAMAP	= ATA_QCFLAG_SG | ATA_QCFLAG_SINGLE,
 	ATA_QCFLAG_IO		= (1 << 3), /* standard IO command */
 	ATA_QCFLAG_RESULT_TF	= (1 << 4), /* result TF requested */
+	ATA_QCFLAG_CLEAR_EXCL	= (1 << 5), /* clear excl_link on completion */
 
 	ATA_QCFLAG_FAILED	= (1 << 16), /* cmd failed and is owned by EH */
 	ATA_QCFLAG_SENSE_VALID	= (1 << 17), /* sense data valid */
@@ -576,11 +577,13 @@ struct ata_port {
 	struct ata_queued_cmd	qcmd[ATA_MAX_QUEUE];
 	unsigned long		qc_allocated;
 	unsigned int		qc_active;
+	int			nr_active_links; /* #links with active qcs */
 
 	struct ata_link		link;	/* host default link */
 
 	int			nr_pmp_links;	/* nr of available PMP links */
 	struct ata_link		*pmp_link;	/* array of PMP links */
+	struct ata_link		*excl_link;	/* for PMP qc exclusion */
 
 	struct ata_port_stats	stats;
 	struct ata_host		*host;
@@ -1093,6 +1096,11 @@ static inline int ata_link_max_devices(const struct ata_link *link)
 	return 1;
 }
 
+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 (ap->nr_pmp_links)
-- 
1.5.0.3

[PATCHSET 1/2] libata: prep for PMP support, take 6

[Tejun Heo]

Hello, all.

This is the sixth take of libata-pmp-prep patchset.  This patchset
contains 12 patches implementing various stuff needed for PMP.

#01-04	: various small stuff
#05-06	: qc_defer mechanism implementation
#07-11	: link/device quirks and EH fast-fail path - things needed to
	  handle quirky PMP fan-out links / pseudo devices.
#12	: AN demultiplexer - sata_async_notification()

Change from the last take[L] are...

* Updated to handle both ATAPI AN and PMP AN as ATAPI AN has been
  merged inbetween.  This is done by adding new patch #01 and updating
  patch #12.

This patchset is against

  libata-dev#upstream (b56feca2ede0dd11a8409743ff14cf14cbcf5062)
  + [1] sata_sil24-fix-IRQ-clearing-race-when-PCIX_IRQ_WOC-is-used

Thanks.

--
tejun

[L] http://thread.gmane.org/gmane.linux.ide/20857
[1] http://article.gmane.org/gmane.linux.ide/22918 

[PATCH 01/12] libata: misc updates for AN

[Tejun Heo]

Update AN support in preparation of PMP support.

* s/ata_id_has_AN/ata_id_has_atapi_AN/
* add AN enabled reporting during configuration
* add err_mask to AN configuration failure reporting
* update LOCKING comment for ata_scsi_media_change_notify()
* check whether ATA dev is attached to SCSI dev ata_scsi_media_change_notify()
* set ATA_FLAG_AN in ahci and sata_sil24

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Kriten Carlson Accardi <kristen.c.accardi@intel.com>
---
 drivers/ata/ahci.c        |    2 +-
 drivers/ata/libata-core.c |   24 ++++++++++++++----------
 drivers/ata/libata-scsi.c |    7 ++++---
 drivers/ata/sata_sil24.c  |   13 +++++++++++--
 include/linux/ata.h       |    2 +-
 5 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index b721569..0a6b694 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -177,7 +177,7 @@ enum {
 
 	AHCI_FLAG_COMMON		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
 					  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
-					  ATA_FLAG_ACPI_SATA,
+					  ATA_FLAG_ACPI_SATA | ATA_FLAG_AN,
 	AHCI_LFLAG_COMMON		= ATA_LFLAG_SKIP_D2H_BSY,
 };
 
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2116f27..63274b6 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2012,7 +2012,8 @@ int ata_dev_configure(struct ata_device *dev)
 
 	/* ATAPI-specific feature tests */
 	else if (dev->class == ATA_DEV_ATAPI) {
-		char *cdb_intr_string = "";
+		const char *cdb_intr_string = "";
+		const char *atapi_an_string = "";
 
 		rc = atapi_cdb_len(id);
 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
@@ -2028,16 +2029,19 @@ int ata_dev_configure(struct ata_device *dev)
 		 * check to see if this ATAPI device supports
 		 * Asynchronous Notification
 		 */
-		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_AN(id)) {
-			int err;
+		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id)) {
+			unsigned int err_mask;
+
 			/* issue SET feature command to turn this on */
-			err = ata_dev_set_AN(dev, SETFEATURES_SATA_ENABLE);
-			if (err)
+			err_mask = ata_dev_set_AN(dev, SETFEATURES_SATA_ENABLE);
+			if (err_mask)
 				ata_dev_printk(dev, KERN_ERR,
-						"unable to set AN, err %x\n",
-						err);
-			else
+					"failed to enable ATAPI AN "
+					"(err_mask=0x%x)\n", err_mask);
+			else {
 				dev->flags |= ATA_DFLAG_AN;
+				atapi_an_string = ", ATAPI AN";
+			}
 		}
 
 		if (ata_id_cdb_intr(dev->id)) {
@@ -2048,10 +2052,10 @@ int ata_dev_configure(struct ata_device *dev)
 		/* print device info to dmesg */
 		if (ata_msg_drv(ap) && print_info)
 			ata_dev_printk(dev, KERN_INFO,
-				       "ATAPI: %s, %s, max %s%s\n",
+				       "ATAPI: %s, %s, max %s%s%s\n",
 				       modelbuf, fwrevbuf,
 				       ata_mode_string(xfer_mask),
-				       cdb_intr_string);
+				       cdb_intr_string, atapi_an_string);
 	}
 
 	/* determine max_sectors */
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 35284b3..518d475 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3161,12 +3161,13 @@ static void ata_scsi_handle_link_detach(struct ata_link *link)
  *	event.
  *
  * 	LOCKING:
- * 	interrupt context, may not sleep.
+ * 	spin_lock_irqsave(host lock)
  */
-void ata_scsi_media_change_notify(struct ata_device *atadev)
+void ata_scsi_media_change_notify(struct ata_device *dev)
 {
 #ifdef OTHER_AN_PATCHES_HAVE_BEEN_APPLIED
-	scsi_device_event_notify(atadev->sdev, SDEV_MEDIA_CHANGE);
+	if (dev->sdev)
+		scsi_device_event_notify(dev->sdev, SDEV_MEDIA_CHANGE);
 #endif
 }
 EXPORT_SYMBOL_GPL(ata_scsi_media_change_notify);
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index 3dcb223..d9c010a 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -168,7 +168,7 @@ enum {
 
 	DEF_PORT_IRQ		= PORT_IRQ_COMPLETE | PORT_IRQ_ERROR |
 				  PORT_IRQ_PHYRDY_CHG | PORT_IRQ_DEV_XCHG |
-				  PORT_IRQ_UNK_FIS,
+				  PORT_IRQ_UNK_FIS | PORT_IRQ_SDB_NOTIFY,
 
 	/* bits[27:16] are unmasked (raw) */
 	PORT_IRQ_RAW_SHIFT	= 16,
@@ -237,7 +237,8 @@ enum {
 	/* host flags */
 	SIL24_COMMON_FLAGS	= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
 				  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
-				  ATA_FLAG_NCQ | ATA_FLAG_ACPI_SATA,
+				  ATA_FLAG_NCQ | ATA_FLAG_ACPI_SATA |
+				  ATA_FLAG_AN,
 	SIL24_COMMON_LFLAGS	= ATA_LFLAG_SKIP_D2H_BSY,
 	SIL24_FLAG_PCIX_IRQ_WOC	= (1 << 24), /* IRQ loss errata on PCI-X */
 
@@ -818,6 +819,14 @@ static void sil24_error_intr(struct ata_port *ap)
 
 	ata_ehi_push_desc(ehi, "irq_stat 0x%08x", irq_stat);
 
+	if (irq_stat & PORT_IRQ_SDB_NOTIFY) {
+		struct ata_device *dev = ap->link.device;
+
+		ata_ehi_push_desc(ehi, "SDB notify");
+		if (dev->flags & ATA_DFLAG_AN)
+			ata_scsi_media_change_notify(dev);
+	}
+
 	if (irq_stat & (PORT_IRQ_PHYRDY_CHG | PORT_IRQ_DEV_XCHG)) {
 		ata_ehi_hotplugged(ehi);
 		ata_ehi_push_desc(ehi, "%s",
diff --git a/include/linux/ata.h b/include/linux/ata.h
index a749f00..21f00a0 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -353,7 +353,7 @@ struct ata_taskfile {
 #define ata_id_queue_depth(id)	(((id)[75] & 0x1f) + 1)
 #define ata_id_removeable(id)	((id)[0] & (1 << 7))
 #define ata_id_has_dword_io(id)	((id)[48] & (1 << 0))
-#define ata_id_has_AN(id)	\
+#define ata_id_has_atapi_AN(id)	\
 	( (((id)[76] != 0x0000) && ((id)[76] != 0xffff)) && \
 	  ((id)[78] & (1 << 5)) )
 #define ata_id_iordy_disable(id) ((id)[49] & (1 << 10))
-- 
1.5.0.3

[PATCH 02/12] libata-pmp-prep: add PMP related constants, fields, ops and update helpers

[Tejun Heo]

Add PMP related constants, fields and ops.  Also, update
ata_class_enabled/disabled() such that PMP classes are considered.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 include/linux/libata.h |   30 ++++++++++++++++++++++++++----
 1 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 3ab2196..c3820f1 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -155,7 +155,11 @@ enum {
 	ATA_DEV_ATA_UNSUP	= 2,	/* ATA device (unsupported) */
 	ATA_DEV_ATAPI		= 3,	/* ATAPI device */
 	ATA_DEV_ATAPI_UNSUP	= 4,	/* ATAPI device (unsupported) */
-	ATA_DEV_NONE		= 5,	/* no device */
+	ATA_DEV_PMP		= 5,	/* SATA port multiplier */
+	ATA_DEV_PMP_UNSUP	= 6,	/* SATA port multiplier (unsupported) */
+	ATA_DEV_SEMB		= 7,	/* SEMB */
+	ATA_DEV_SEMB_UNSUP	= 8,	/* SEMB (unsupported) */
+	ATA_DEV_NONE		= 9,	/* no device */
 
 	/* struct ata_link flags */
 	ATA_LFLAG_HRST_TO_RESUME = (1 << 0), /* hardreset to resume link */
@@ -181,6 +185,7 @@ enum {
 	ATA_FLAG_NO_IORDY	= (1 << 16), /* controller lacks iordy */
 	ATA_FLAG_ACPI_SATA	= (1 << 17), /* need native SATA ACPI layout */
 	ATA_FLAG_AN		= (1 << 18), /* controller supports AN */
+	ATA_FLAG_PMP		= (1 << 19), /* controller supports PMP */
 
 	/* The following flag belongs to ap->pflags but is kept in
 	 * ap->flags because it's referenced in many LLDs and will be
@@ -299,6 +304,10 @@ enum {
 	/* how hard are we gonna try to probe/recover devices */
 	ATA_PROBE_MAX_TRIES	= 3,
 	ATA_EH_DEV_TRIES	= 3,
+	ATA_EH_PMP_TRIES	= 5,
+	ATA_EH_PMP_LINK_TRIES	= 3,
+
+	SATA_PMP_SCR_TIMEOUT	= 250,
 
 	/* Horkage types. May be set by libata or controller on drives
 	   (some horkage may be drive/controller pair dependant */
@@ -450,7 +459,12 @@ 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 */
-	u16			id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */
+
+	union {
+		u16		id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */
+		u32		gscr[SATA_PMP_GSCR_DWORDS]; /* PMP GSCR block */
+	};
+
 	u8			pio_mode;
 	u8			dma_mode;
 	u8			xfer_mode;
@@ -628,6 +642,12 @@ struct ata_port_operations {
 	void (*qc_prep) (struct ata_queued_cmd *qc);
 	unsigned int (*qc_issue) (struct ata_queued_cmd *qc);
 
+	/* port multiplier */
+	void (*pmp_attach) (struct ata_port *ap);
+	void (*pmp_detach) (struct ata_port *ap);
+	int (*pmp_read) (struct ata_device *dev, int pmp, int reg, u32 *r_val);
+	int (*pmp_write) (struct ata_device *dev, int pmp, int reg, u32 val);
+
 	/* Error handlers.  ->error_handler overrides ->eng_timeout and
 	 * indicates that new-style EH is in place.
 	 */
@@ -1033,12 +1053,14 @@ static inline unsigned int ata_tag_internal(unsigned int tag)
  */
 static inline unsigned int ata_class_enabled(unsigned int class)
 {
-	return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI;
+	return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI ||
+		class == ATA_DEV_PMP || class == ATA_DEV_SEMB;
 }
 
 static inline unsigned int ata_class_disabled(unsigned int class)
 {
-	return class == ATA_DEV_ATA_UNSUP || class == ATA_DEV_ATAPI_UNSUP;
+	return class == ATA_DEV_ATA_UNSUP || class == ATA_DEV_ATAPI_UNSUP ||
+		class == ATA_DEV_PMP_UNSUP || class == ATA_DEV_SEMB_UNSUP;
 }
 
 static inline unsigned int ata_class_absent(unsigned int class)
-- 
1.5.0.3

[PATCH 03/12] libata-pmp-prep: add @new_class to ata_dev_revalidate()

[Tejun Heo]

Consider newly found class code while revalidating.  PMP resetting
always results in valid class code and issuing PMP commands to
ATA/ATAPI device isn't very attractive.  Add @new_class to
ata_dev_revalidate() and check class code for revalidation.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-core.c |   15 +++++++++++++--
 drivers/ata/libata-eh.c   |    3 ++-
 drivers/ata/libata.h      |    3 ++-
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 63274b6..bcddc93 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2848,7 +2848,7 @@ static int ata_dev_set_mode(struct ata_device *dev)
 	}
 
 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
-	rc = ata_dev_revalidate(dev, 0);
+	rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
 	if (rc)
 		return rc;
@@ -3752,6 +3752,7 @@ int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
 /**
  *	ata_dev_revalidate - Revalidate ATA device
  *	@dev: device to revalidate
+ *	@new_class: new class code
  *	@readid_flags: read ID flags
  *
  *	Re-read IDENTIFY page, make sure @dev is still attached to the
@@ -3763,7 +3764,8 @@ int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
  *	RETURNS:
  *	0 on success, negative errno otherwise
  */
-int ata_dev_revalidate(struct ata_device *dev, unsigned int readid_flags)
+int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
+		       unsigned int readid_flags)
 {
 	u64 n_sectors = dev->n_sectors;
 	int rc;
@@ -3771,6 +3773,15 @@ int ata_dev_revalidate(struct ata_device *dev, unsigned int readid_flags)
 	if (!ata_dev_enabled(dev))
 		return -ENODEV;
 
+	/* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
+	if (ata_class_enabled(new_class) &&
+	    new_class != ATA_DEV_ATA && new_class != ATA_DEV_ATAPI) {
+		ata_dev_printk(dev, KERN_INFO, "class mismatch %u != %u\n",
+			       dev->class, new_class);
+		rc = -ENODEV;
+		goto fail;
+	}
+
 	/* re-read ID */
 	rc = ata_dev_reread_id(dev, readid_flags);
 	if (rc)
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index daa2f74..eb087bb 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2104,7 +2104,8 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
 			}
 
 			ata_eh_about_to_do(link, dev, ATA_EH_REVALIDATE);
-			rc = ata_dev_revalidate(dev, readid_flags);
+			rc = ata_dev_revalidate(dev, ehc->classes[dev->devno],
+						readid_flags);
 			if (rc)
 				goto err;
 
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 11f64a4..3457048 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -77,7 +77,8 @@ extern unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd);
 extern int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
 			   unsigned int flags, u16 *id);
 extern int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags);
-extern int ata_dev_revalidate(struct ata_device *dev, unsigned int readid_flags);
+extern int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
+			      unsigned int readid_flags);
 extern int ata_dev_configure(struct ata_device *dev);
 extern int sata_down_spd_limit(struct ata_link *link);
 extern int sata_set_spd_needed(struct ata_link *link);
-- 
1.5.0.3

[PATCH 04/12] libata-pmp-prep: make a number of functions global to libata

[Tejun Heo]

Make a number of functions from libata-core.c and libata-eh.c global
to libata (drivers/ata/libata.h).  These will be used by PMP.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-core.c |    4 ++--
 drivers/ata/libata-eh.c   |   31 +++++++++++++++----------------
 drivers/ata/libata.h      |   17 +++++++++++++++++
 3 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index bcddc93..c33a1f8 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6220,7 +6220,7 @@ void ata_dev_init(struct ata_device *dev)
  *	LOCKING:
  *	Kernel thread context (may sleep)
  */
-static void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
+void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
 {
 	int i;
 
@@ -6255,7 +6255,7 @@ static void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
  *	RETURNS:
  *	0 on success, -errno on failure.
  */
-static int sata_link_init_spd(struct ata_link *link)
+int sata_link_init_spd(struct ata_link *link)
 {
 	u32 scontrol, spd;
 	int rc;
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index eb087bb..1d3b0dc 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -74,7 +74,6 @@ static const unsigned long ata_eh_reset_timeouts[] = {
 };
 
 static void __ata_port_freeze(struct ata_port *ap);
-static void ata_eh_finish(struct ata_port *ap);
 #ifdef CONFIG_PM
 static void ata_eh_handle_port_suspend(struct ata_port *ap);
 static void ata_eh_handle_port_resume(struct ata_port *ap);
@@ -1015,7 +1014,7 @@ void ata_eh_qc_retry(struct ata_queued_cmd *qc)
  *	LOCKING:
  *	None.
  */
-static void ata_eh_detach_dev(struct ata_device *dev)
+void ata_eh_detach_dev(struct ata_device *dev)
 {
 	struct ata_link *link = dev->link;
 	struct ata_port *ap = link->ap;
@@ -1052,8 +1051,8 @@ static void ata_eh_detach_dev(struct ata_device *dev)
  *	LOCKING:
  *	None.
  */
-static void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
-			       unsigned int action)
+void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
+			unsigned int action)
 {
 	struct ata_port *ap = link->ap;
 	struct ata_eh_info *ehi = &link->eh_info;
@@ -1095,8 +1094,8 @@ static void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
  *	LOCKING:
  *	None.
  */
-static void ata_eh_done(struct ata_link *link, struct ata_device *dev,
-			unsigned int action)
+void ata_eh_done(struct ata_link *link, struct ata_device *dev,
+		 unsigned int action)
 {
 	struct ata_eh_context *ehc = &link->eh_context;
 
@@ -1756,7 +1755,7 @@ static void ata_eh_link_autopsy(struct ata_link *link)
  *	LOCKING:
  *	Kernel thread context (may sleep).
  */
-static void ata_eh_autopsy(struct ata_port *ap)
+void ata_eh_autopsy(struct ata_port *ap)
 {
 	struct ata_link *link;
 
@@ -1867,7 +1866,7 @@ static void ata_eh_link_report(struct ata_link *link)
  *	LOCKING:
  *	None.
  */
-static void ata_eh_report(struct ata_port *ap)
+void ata_eh_report(struct ata_port *ap)
 {
 	struct ata_link *link;
 
@@ -1918,9 +1917,9 @@ static int ata_eh_followup_srst_needed(int rc, int classify,
 	return 0;
 }
 
-static int ata_eh_reset(struct ata_link *link, int classify,
-			ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
-			ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+int ata_eh_reset(struct ata_link *link, int classify,
+		 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
+		 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
 	struct ata_eh_context *ehc = &link->eh_context;
 	unsigned int *classes = ehc->classes;
@@ -2296,10 +2295,10 @@ static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
  *	RETURNS:
  *	0 on success, -errno on failure.
  */
-static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
-			  ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
-			  ata_postreset_fn_t postreset,
-			  struct ata_link **r_failed_link)
+int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
+		   ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+		   ata_postreset_fn_t postreset,
+		   struct ata_link **r_failed_link)
 {
 	struct ata_link *link;
 	struct ata_device *dev;
@@ -2445,7 +2444,7 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
  *	LOCKING:
  *	None.
  */
-static void ata_eh_finish(struct ata_port *ap)
+void ata_eh_finish(struct ata_port *ap)
 {
 	int tag;
 
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 3457048..e380423 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -94,6 +94,8 @@ extern void ata_dev_select(struct ata_port *ap, unsigned int device,
 extern void swap_buf_le16(u16 *buf, unsigned int buf_words);
 extern int ata_flush_cache(struct ata_device *dev);
 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);
 extern int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg);
 extern int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg);
 extern struct ata_port *ata_port_alloc(struct ata_host *host);
@@ -155,6 +157,21 @@ extern void ata_scsi_error(struct Scsi_Host *host);
 extern void ata_port_wait_eh(struct ata_port *ap);
 extern void ata_eh_fastdrain_timerfn(unsigned long arg);
 extern void ata_qc_schedule_eh(struct ata_queued_cmd *qc);
+extern void ata_eh_detach_dev(struct ata_device *dev);
+extern void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
+			       unsigned int action);
+extern void ata_eh_done(struct ata_link *link, struct ata_device *dev,
+			unsigned int action);
+extern void ata_eh_autopsy(struct ata_port *ap);
+extern void ata_eh_report(struct ata_port *ap);
+extern int ata_eh_reset(struct ata_link *link, int classify,
+			ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
+			ata_reset_fn_t hardreset, ata_postreset_fn_t postreset);
+extern int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
+			  ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+			  ata_postreset_fn_t postreset,
+			  struct ata_link **r_failed_disk);
+extern void ata_eh_finish(struct ata_port *ap);
 
 /* libata-sff.c */
 extern u8 ata_irq_on(struct ata_port *ap);
-- 
1.5.0.3

[PATCH 07/12] libata-pmp-prep: implement ATA_LFLAG_NO_SRST, ASSUME_ATA and ASSUME_SEMB

[Tejun Heo]

Some links on some PMPs locks up on SRST and/or report incorrect
device signature.  Implement ATA_LFLAG_NO_SRST, ASSUME_ATA and
ASSUME_SEMB to handle these quirky links.  NO_SRST makes EH avoid
SRST.  ASSUME_ATA and SEMB forces class code to ATA and SEMB_UNSUP
respectively.  Note that SEMB isn't currently supported yet so the
_UNSUP variant is used.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-eh.c |   42 ++++++++++++++++++++++++++++++++----------
 include/linux/libata.h  |    4 ++++
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 5244723..7be04bd 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1906,14 +1906,18 @@ static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
 	return 0;
 }
 
-static int ata_eh_followup_srst_needed(int rc, int classify,
+static int ata_eh_followup_srst_needed(struct ata_link *link,
+				       int rc, int classify,
 				       const unsigned int *classes)
 {
+	if (link->flags & ATA_LFLAG_NO_SRST)
+		return 0;
 	if (rc == -EAGAIN)
 		return 1;
 	if (rc != 0)
 		return 0;
-	if (classify && classes[0] == ATA_DEV_UNKNOWN)
+	if (classify && !(link->flags & ATA_LFLAG_ASSUME_CLASS) &&
+	    classes[0] == ATA_DEV_UNKNOWN)
 		return 1;
 	return 0;
 }
@@ -1940,7 +1944,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	 */
 	action = ehc->i.action;
 	ehc->i.action &= ~ATA_EH_RESET_MASK;
-	if (softreset && (!hardreset || (!sata_set_spd_needed(link) &&
+	if (softreset && (!hardreset || (!(link->flags & ATA_LFLAG_NO_SRST) &&
+					 !sata_set_spd_needed(link) &&
 					 !(action & ATA_EH_HARDRESET))))
 		ehc->i.action |= ATA_EH_SOFTRESET;
 	else
@@ -2003,7 +2008,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	rc = ata_do_reset(link, reset, classes, deadline);
 
 	if (reset == hardreset &&
-	    ata_eh_followup_srst_needed(rc, classify, classes)) {
+	    ata_eh_followup_srst_needed(link, rc, classify, classes)) {
 		/* okay, let's do follow-up softreset */
 		reset = softreset;
 
@@ -2018,8 +2023,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
 		ata_eh_about_to_do(link, NULL, ATA_EH_RESET_MASK);
 		rc = ata_do_reset(link, reset, classes, deadline);
 
-		if (rc == 0 && classify &&
-		    classes[0] == ATA_DEV_UNKNOWN) {
+		if (rc == 0 && classify && classes[0] == ATA_DEV_UNKNOWN &&
+		    !(link->flags & ATA_LFLAG_ASSUME_CLASS)) {
 			ata_link_printk(link, KERN_ERR,
 					"classification failed\n");
 			rc = -EINVAL;
@@ -2027,6 +2032,10 @@ int ata_eh_reset(struct ata_link *link, int classify,
 		}
 	}
 
+	/* if we skipped follow-up srst, clear rc */
+	if (rc == -EAGAIN)
+		rc = 0;
+
 	if (rc && try < ARRAY_SIZE(ata_eh_reset_timeouts)) {
 		unsigned long now = jiffies;
 
@@ -2051,12 +2060,25 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	if (rc == 0) {
 		u32 sstatus;
 
-		/* After the reset, the device state is PIO 0 and the
-		 * controller state is undefined.  Record the mode.
-		 */
-		ata_link_for_each_dev(dev, link)
+		ata_link_for_each_dev(dev, link) {
+			/* After the reset, the device state is PIO 0
+			 * and the controller state is undefined.
+			 * Record the mode.
+			 */
 			dev->pio_mode = XFER_PIO_0;
 
+			if (ata_link_offline(link))
+				continue;
+
+			/* apply class override and convert UNKNOWN to NONE */
+			if (link->flags & ATA_LFLAG_ASSUME_ATA)
+				classes[dev->devno] = ATA_DEV_ATA;
+			else if (link->flags & ATA_LFLAG_ASSUME_SEMB)
+				classes[dev->devno] = ATA_DEV_SEMB_UNSUP; /* not yet */
+			else if (classes[dev->devno] == ATA_DEV_UNKNOWN)
+				classes[dev->devno] = ATA_DEV_NONE;
+		}
+
 		/* record current link speed */
 		if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
 			link->sata_spd = (sstatus >> 4) & 0xf;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index f9f81fd..6266fff 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -165,6 +165,10 @@ enum {
 	ATA_LFLAG_HRST_TO_RESUME = (1 << 0), /* hardreset to resume link */
 	ATA_LFLAG_SKIP_D2H_BSY	= (1 << 1), /* can't wait for the first D2H
 					     * Register FIS clearing BSY */
+	ATA_LFLAG_NO_SRST	= (1 << 2), /* avoid softreset */
+	ATA_LFLAG_ASSUME_ATA	= (1 << 3), /* assume ATA class */
+	ATA_LFLAG_ASSUME_SEMB	= (1 << 4), /* assume SEMB class */
+	ATA_LFLAG_ASSUME_CLASS	= ATA_LFLAG_ASSUME_ATA | ATA_LFLAG_ASSUME_SEMB,
 
 	/* struct ata_port flags */
 	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */
-- 
1.5.0.3

[PATCH 05/12] libata-pmp-prep: implement ops->qc_defer()

[Tejun Heo]

Controllers which support PMP have various restrictions on which
combinations of commands are allowed to what number of devices
concurrently.  This patch implements ops->qc_defer() which determines
whether a qc can be issued at the moment or should be deferred.

If the function returns ATA_DEFER_LINK, the qc will be deferred until
a qc completes on the link.  If ATA_DEFER_PORT, until a qc completes
on any link.  The defer conditions are advisory and in general
ATA_DEFER_LINK can be considered as lower priority deferring than
ATA_DEFER_PORT.

ops->qc_defer() replaces fixed ata_scmd_need_defer().  For standard
NCQ/non-NCQ exclusion, ata_std_qc_defer() is implemented.  ahci and
sata_sil24 are converted to use ata_std_qc_defer().

ops->qc_defer() is heavier than the original mechanism because full qc
is prepped before determining to defer it, but various information is
needed to determine defer conditinos and fully translating a qc is the
only way to supply such information in generic manner.

IMHO, this shouldn't cause any noticeable performance issues as

* for most cases deferring occurs rarely (except for NCQ-aware
  cmd-switching PMP)
* translation itself isn't that expensive
* once deferred the command won't be repeated until another command
  completes which usually is a very long time cpu-wise.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/ahci.c        |    2 +
 drivers/ata/libata-core.c |   31 ++++++++++++++++++++++
 drivers/ata/libata-scsi.c |   62 +++++++++++++++++++--------------------------
 drivers/ata/sata_nv.c     |    1 +
 drivers/ata/sata_sil24.c  |    1 +
 include/linux/libata.h    |    6 ++++
 6 files changed, 67 insertions(+), 36 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 0a6b694..cf34044 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -268,6 +268,7 @@ static const struct ata_port_operations ahci_ops = {
 
 	.tf_read		= ahci_tf_read,
 
+	.qc_defer		= ata_std_qc_defer,
 	.qc_prep		= ahci_qc_prep,
 	.qc_issue		= ahci_qc_issue,
 
@@ -298,6 +299,7 @@ static const struct ata_port_operations ahci_vt8251_ops = {
 
 	.tf_read		= ahci_tf_read,
 
+	.qc_defer		= ata_std_qc_defer,
 	.qc_prep		= ahci_qc_prep,
 	.qc_issue		= ahci_qc_issue,
 
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index c33a1f8..7dd666e 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4348,6 +4348,36 @@ int ata_check_atapi_dma(struct ata_queued_cmd *qc)
 }
 
 /**
+ *	ata_std_qc_defer - Check whether a qc needs to be deferred
+ *	@qc: ATA command in question
+ *
+ *	Non-NCQ commands cannot run with any other command, NCQ or
+ *	not.  As upper layer only knows the queue depth, we are
+ *	responsible for maintaining exclusion.  This function checks
+ *	whether a new command @qc can be issued.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ *
+ *	RETURNS:
+ *	ATA_DEFER_* if deferring is needed, 0 otherwise.
+ */
+int ata_std_qc_defer(struct ata_queued_cmd *qc)
+{
+	struct ata_link *link = qc->dev->link;
+
+	if (qc->tf.protocol == ATA_PROT_NCQ) {
+		if (!ata_tag_valid(link->active_tag))
+			return 0;
+	} else {
+		if (!ata_tag_valid(link->active_tag) && !link->sactive)
+			return 0;
+	}
+
+	return ATA_DEFER_LINK;
+}
+
+/**
  *	ata_qc_prep - Prepare taskfile for submission
  *	@qc: Metadata associated with taskfile to be prepared
  *
@@ -7113,6 +7143,7 @@ EXPORT_SYMBOL_GPL(ata_interrupt);
 EXPORT_SYMBOL_GPL(ata_do_set_mode);
 EXPORT_SYMBOL_GPL(ata_data_xfer);
 EXPORT_SYMBOL_GPL(ata_data_xfer_noirq);
+EXPORT_SYMBOL_GPL(ata_std_qc_defer);
 EXPORT_SYMBOL_GPL(ata_qc_prep);
 EXPORT_SYMBOL_GPL(ata_dumb_qc_prep);
 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 518d475..eb611b4 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -750,6 +750,13 @@ static void ata_scsi_sdev_config(struct scsi_device *sdev)
 {
 	sdev->use_10_for_rw = 1;
 	sdev->use_10_for_ms = 1;
+
+	/* Schedule policy is determined by ->qc_defer() callback and
+	 * it needs to see every deferred qc.  Set dev_blocked to 1 to
+	 * prevent SCSI midlayer from automatically deferring
+	 * requests.
+	 */
+	sdev->max_device_blocked = 1;
 }
 
 static void ata_scsi_dev_config(struct scsi_device *sdev,
@@ -1417,37 +1424,6 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 }
 
 /**
- *	ata_scmd_need_defer - Check whether we need to defer scmd
- *	@dev: ATA device to which the command is addressed
- *	@is_io: Is the command IO (and thus possibly NCQ)?
- *
- *	NCQ and non-NCQ commands cannot run together.  As upper layer
- *	only knows the queue depth, we are responsible for maintaining
- *	exclusion.  This function checks whether a new command can be
- *	issued to @dev.
- *
- *	LOCKING:
- *	spin_lock_irqsave(host lock)
- *
- *	RETURNS:
- *	1 if deferring is needed, 0 otherwise.
- */
-static int ata_scmd_need_defer(struct ata_device *dev, int is_io)
-{
-	struct ata_link *link = dev->link;
-	int is_ncq = is_io && ata_ncq_enabled(dev);
-
-	if (is_ncq) {
-		if (!ata_tag_valid(link->active_tag))
-			return 0;
-	} else {
-		if (!ata_tag_valid(link->active_tag) && !link->sactive)
-			return 0;
-	}
-	return 1;
-}
-
-/**
  *	ata_scsi_translate - Translate then issue SCSI command to ATA device
  *	@dev: ATA device to which the command is addressed
  *	@cmd: SCSI command to execute
@@ -1478,14 +1454,12 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 			      void (*done)(struct scsi_cmnd *),
 			      ata_xlat_func_t xlat_func)
 {
+	struct ata_port *ap = dev->link->ap;
 	struct ata_queued_cmd *qc;
-	int is_io = xlat_func == ata_scsi_rw_xlat;
+	int rc;
 
 	VPRINTK("ENTER\n");
 
-	if (unlikely(ata_scmd_need_defer(dev, is_io)))
-		goto defer;
-
 	qc = ata_scsi_qc_new(dev, cmd, done);
 	if (!qc)
 		goto err_mem;
@@ -1509,6 +1483,11 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 	if (xlat_func(qc))
 		goto early_finish;
 
+	if (ap->ops->qc_defer) {
+		if ((rc = ap->ops->qc_defer(qc)))
+			goto defer;
+	}
+
 	/* select device, send command to hardware */
 	ata_qc_issue(qc);
 
@@ -1530,8 +1509,12 @@ err_mem:
 	return 0;
 
 defer:
+	ata_qc_free(qc);
 	DPRINTK("EXIT - defer\n");
-	return SCSI_MLQUEUE_DEVICE_BUSY;
+	if (rc == ATA_DEFER_LINK)
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+	else
+		return SCSI_MLQUEUE_HOST_BUSY;
 }
 
 /**
@@ -2957,6 +2940,13 @@ int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
 		shost->max_channel = 1;
 		shost->max_cmd_len = 16;
 
+		/* Schedule policy is determined by ->qc_defer()
+		 * callback and it needs to see every deferred qc.
+		 * Set host_blocked to 1 to prevent SCSI midlayer from
+		 * automatically deferring requests.
+		 */
+		shost->max_host_blocked = 1;
+
 		rc = scsi_add_host(ap->scsi_host, ap->host->dev);
 		if (rc)
 			goto err_add;
diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index b860f99..40557fe 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -423,6 +423,7 @@ static const struct ata_port_operations nv_adma_ops = {
 	.bmdma_start		= ata_bmdma_start,
 	.bmdma_stop		= ata_bmdma_stop,
 	.bmdma_status		= ata_bmdma_status,
+	.qc_defer		= ata_std_qc_defer,
 	.qc_prep		= nv_adma_qc_prep,
 	.qc_issue		= nv_adma_qc_issue,
 	.freeze			= nv_adma_freeze,
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index d9c010a..9acfce4 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -393,6 +393,7 @@ static const struct ata_port_operations sil24_ops = {
 
 	.tf_read		= sil24_tf_read,
 
+	.qc_defer		= ata_std_qc_defer,
 	.qc_prep		= sil24_qc_prep,
 	.qc_issue		= sil24_qc_issue,
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index c3820f1..b0d4ca0 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -272,6 +272,10 @@ enum {
 	/* ering size */
 	ATA_ERING_SIZE		= 32,
 
+	/* return values for ->qc_defer */
+	ATA_DEFER_LINK		= 1,
+	ATA_DEFER_PORT		= 2,
+
 	/* desc_len for ata_eh_info and context */
 	ATA_EH_DESC_LEN		= 80,
 
@@ -639,6 +643,7 @@ struct ata_port_operations {
 
 	void (*data_xfer) (struct ata_device *, unsigned char *, unsigned int, int);
 
+	int (*qc_defer) (struct ata_queued_cmd *qc);
 	void (*qc_prep) (struct ata_queued_cmd *qc);
 	unsigned int (*qc_issue) (struct ata_queued_cmd *qc);
 
@@ -824,6 +829,7 @@ extern void ata_data_xfer(struct ata_device *adev, unsigned char *buf,
 			  unsigned int buflen, int write_data);
 extern void ata_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
 				unsigned int buflen, int write_data);
+extern int ata_std_qc_defer(struct ata_queued_cmd *qc);
 extern void ata_dumb_qc_prep(struct ata_queued_cmd *qc);
 extern void ata_qc_prep(struct ata_queued_cmd *qc);
 extern void ata_noop_qc_prep(struct ata_queued_cmd *qc);
-- 
1.5.0.3

[PATCH 08/12] libata-pmp-prep: implement ATA_LFLAG_NO_RETRY

[Tejun Heo]

Some PMP links are connected to internal pseudo devices which may come
and go depending on situation.  There's no reason to try hard to
recover them.  ATA_LFLAG_NO_RETRY tells EH to not retry if the device
attached to the link fails.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-eh.c |    5 ++++-
 include/linux/libata.h  |    1 +
 2 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 7be04bd..8f8ed4d 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2335,7 +2335,10 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		struct ata_eh_context *ehc = &link->eh_context;
 
 		ata_link_for_each_dev(dev, link) {
-			ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
+			if (link->flags & ATA_LFLAG_NO_RETRY)
+				ehc->tries[dev->devno] = 1;
+			else
+				ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
 
 			/* collect port action mask recorded in dev actions */
 			ehc->i.action |= ehc->i.dev_action[dev->devno] &
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6266fff..adeee73 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -169,6 +169,7 @@ enum {
 	ATA_LFLAG_ASSUME_ATA	= (1 << 3), /* assume ATA class */
 	ATA_LFLAG_ASSUME_SEMB	= (1 << 4), /* assume SEMB class */
 	ATA_LFLAG_ASSUME_CLASS	= ATA_LFLAG_ASSUME_ATA | ATA_LFLAG_ASSUME_SEMB,
+	ATA_LFLAG_NO_RETRY	= (1 << 5), /* don't retry this link */
 
 	/* struct ata_port flags */
 	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */
-- 
1.5.0.3

[PATCH 06/12] libata-pmp-prep: implement qc_defer helpers

[Tejun Heo]

Implement ap->nr_active_links (the number of links with active qcs),
ap->excl_link (pointer to link which can be used by ->qc_defer and is
cleared when a qc with ATA_QCFLAG_CLEAR_EXCL completes), and
ata_link_active().

These can be used by ->qc_defer() to implement proper command
exclusion.  This set of helpers seem enough for both sil24 (ATAPI
exclusion needed) and cmd-switching PMP.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-core.c |   22 ++++++++++++++++++++--
 drivers/ata/libata-eh.c   |    5 +++++
 include/linux/libata.h    |    8 ++++++++
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 7dd666e..86ef06e 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1392,6 +1392,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	struct ata_queued_cmd *qc;
 	unsigned int tag, preempted_tag;
 	u32 preempted_sactive, preempted_qc_active;
+	int preempted_nr_active_links;
 	DECLARE_COMPLETION_ONSTACK(wait);
 	unsigned long flags;
 	unsigned int err_mask;
@@ -1430,9 +1431,11 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	preempted_tag = link->active_tag;
 	preempted_sactive = link->sactive;
 	preempted_qc_active = ap->qc_active;
+	preempted_nr_active_links = ap->nr_active_links;
 	link->active_tag = ATA_TAG_POISON;
 	link->sactive = 0;
 	ap->qc_active = 0;
+	ap->nr_active_links = 0;
 
 	/* prepare & issue qc */
 	qc->tf = *tf;
@@ -1511,6 +1514,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 	link->active_tag = preempted_tag;
 	link->sactive = preempted_sactive;
 	ap->qc_active = preempted_qc_active;
+	ap->nr_active_links = preempted_nr_active_links;
 
 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
 	 * Until those drivers are fixed, we detect the condition
@@ -5410,10 +5414,19 @@ void __ata_qc_complete(struct ata_queued_cmd *qc)
 		ata_sg_clean(qc);
 
 	/* command should be marked inactive atomically with qc completion */
-	if (qc->tf.protocol == ATA_PROT_NCQ)
+	if (qc->tf.protocol == ATA_PROT_NCQ) {
 		link->sactive &= ~(1 << qc->tag);
-	else
+		if (!link->sactive)
+			ap->nr_active_links--;
+	} else {
 		link->active_tag = ATA_TAG_POISON;
+		ap->nr_active_links--;
+	}
+
+	/* clear exclusive status */
+	if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
+		     ap->excl_link == link))
+		ap->excl_link = NULL;
 
 	/* atapi: mark qc as inactive to prevent the interrupt handler
 	 * from completing the command twice later, before the error handler
@@ -5592,9 +5605,14 @@ void ata_qc_issue(struct ata_queued_cmd *qc)
 
 	if (qc->tf.protocol == ATA_PROT_NCQ) {
 		WARN_ON(link->sactive & (1 << qc->tag));
+
+		if (!link->sactive)
+			ap->nr_active_links++;
 		link->sactive |= 1 << qc->tag;
 	} else {
 		WARN_ON(link->sactive);
+
+		ap->nr_active_links++;
 		link->active_tag = qc->tag;
 	}
 
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 1d3b0dc..5244723 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -451,6 +451,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 
 		ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
 		ap->pflags &= ~ATA_PFLAG_EH_PENDING;
+		ap->excl_link = NULL;	/* don't maintain exclusion over EH */
 
 		spin_unlock_irqrestore(ap->lock, flags);
 
@@ -2474,6 +2475,10 @@ void ata_eh_finish(struct ata_port *ap)
 			}
 		}
 	}
+
+	/* make sure nr_active_links is zero after EH */
+	WARN_ON(ap->nr_active_links);
+	ap->nr_active_links = 0;
 }
 
 /**
diff --git a/include/linux/libata.h b/include/linux/libata.h
index b0d4ca0..f9f81fd 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -216,6 +216,7 @@ enum {
 	ATA_QCFLAG_DMAMAP	= ATA_QCFLAG_SG | ATA_QCFLAG_SINGLE,
 	ATA_QCFLAG_IO		= (1 << 3), /* standard IO command */
 	ATA_QCFLAG_RESULT_TF	= (1 << 4), /* result TF requested */
+	ATA_QCFLAG_CLEAR_EXCL	= (1 << 5), /* clear excl_link on completion */
 
 	ATA_QCFLAG_FAILED	= (1 << 16), /* cmd failed and is owned by EH */
 	ATA_QCFLAG_SENSE_VALID	= (1 << 17), /* sense data valid */
@@ -579,11 +580,13 @@ struct ata_port {
 	struct ata_queued_cmd	qcmd[ATA_MAX_QUEUE];
 	unsigned long		qc_allocated;
 	unsigned int		qc_active;
+	int			nr_active_links; /* #links with active qcs */
 
 	struct ata_link		link;	/* host default link */
 
 	int			nr_pmp_links;	/* nr of available PMP links */
 	struct ata_link		*pmp_link;	/* array of PMP links */
+	struct ata_link		*excl_link;	/* for PMP qc exclusion */
 
 	struct ata_port_stats	stats;
 	struct ata_host		*host;
@@ -1104,6 +1107,11 @@ static inline int ata_link_max_devices(const struct ata_link *link)
 	return 1;
 }
 
+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 (ap->nr_pmp_links)
-- 
1.5.0.3

[PATCH 11/12] libata-pmp-prep: implement ATA_HORKAGE_SKIP_PM

[Tejun Heo]

Some pseudo devices fail PM commands unnecessarily aborting system
suspend.  Implement ATA_HORKAGE_SKIP_PM which makes libata skip PM
commands for these devices.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-scsi.c |    7 +++++++
 include/linux/libata.h    |    1 +
 2 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index eb611b4..a651bdd 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -945,6 +945,13 @@ static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc)
 		goto invalid_fld;       /* LOEJ bit set not supported */
 	if (((cdb[4] >> 4) & 0xf) != 0)
 		goto invalid_fld;       /* power conditions not supported */
+
+	if (qc->dev->horkage & ATA_HORKAGE_SKIP_PM) {
+		/* the device lacks PM support, finish without doing anything */
+		scmd->result = SAM_STAT_GOOD;
+		return 1;
+	}
+
 	if (cdb[4] & 0x1) {
 		tf->nsect = 1;	/* 1 sector, lba=0 */
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2bd1d26..56b2187 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -329,6 +329,7 @@ enum {
 	ATA_HORKAGE_NONCQ	= (1 << 2),	/* Don't use NCQ */
 	ATA_HORKAGE_MAX_SEC_128	= (1 << 3),	/* Limit max sects to 128 */
 	ATA_HORKAGE_BROKEN_HPA	= (1 << 4),	/* Broken HPA */
+	ATA_HORKAGE_SKIP_PM	= (1 << 5),	/* Skip PM operations */
 };
 
 enum hsm_task_states {
-- 
1.5.0.3

[PATCH 09/12] libata-pmp-prep: implement ATA_LFLAG_DISABLED

[Tejun Heo]

Implement ATA_LFLAG_DISABLED.  The flag indicates the link is disabled
due to EH recovery failure.  While a link is disabled, no EH action is
taken on the link and suspend/resume become noop too.

This will be used by PMP links to manage failed links.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-eh.c |   30 +++++++++++++++++++++++++++++-
 include/linux/libata.h  |    3 +++
 2 files changed, 32 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 8f8ed4d..fbbf791 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1308,6 +1308,7 @@ static void ata_eh_analyze_serror(struct ata_link *link)
 	struct ata_eh_context *ehc = &link->eh_context;
 	u32 serror = ehc->i.serror;
 	unsigned int err_mask = 0, action = 0;
+	u32 hotplug_mask;
 
 	if (serror & SERR_PERSISTENT) {
 		err_mask |= AC_ERR_ATA_BUS;
@@ -1326,7 +1327,20 @@ static void ata_eh_analyze_serror(struct ata_link *link)
 		err_mask |= AC_ERR_SYSTEM;
 		action |= ATA_EH_HARDRESET;
 	}
-	if (serror & (SERR_PHYRDY_CHG | SERR_DEV_XCHG))
+
+	/* Determine whether a hotplug event has occurred.  Both
+	 * SError.N/X are considered hotplug events for enabled or
+	 * host links.  For disabled PMP links, only N bit is
+	 * considered as X bit is left at 1 for link plugging.
+	 */
+	hotplug_mask = 0;
+
+	if (!(link->flags & ATA_LFLAG_DISABLED) || ata_is_host_link(link))
+		hotplug_mask = SERR_PHYRDY_CHG | SERR_DEV_XCHG;
+	else
+		hotplug_mask = SERR_PHYRDY_CHG;
+
+	if (serror & hotplug_mask)
 		ata_ehi_hotplugged(&ehc->i);
 
 	ehc->i.err_mask |= err_mask;
@@ -2227,6 +2241,10 @@ static int ata_eh_skip_recovery(struct ata_link *link)
 	struct ata_eh_context *ehc = &link->eh_context;
 	struct ata_device *dev;
 
+	/* skip disabled links */
+	if (link->flags & ATA_LFLAG_DISABLED)
+		return 1;
+
 	/* thaw frozen port, resume link and recover failed devices */
 	if ((link->ap->pflags & ATA_PFLAG_FROZEN) ||
 	    (ehc->i.flags & ATA_EHI_RESUME_LINK) || ata_link_nr_enabled(link))
@@ -2327,6 +2345,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 	struct ata_device *dev;
 	int nr_failed_devs, nr_disabled_devs;
 	int reset, rc;
+	unsigned long flags;
 
 	DPRINTK("ENTER\n");
 
@@ -2334,6 +2353,15 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 	ata_port_for_each_link(link, ap) {
 		struct ata_eh_context *ehc = &link->eh_context;
 
+		/* re-enable link? */
+		if (ehc->i.action & ATA_EH_ENABLE_LINK) {
+			ata_eh_about_to_do(link, NULL, ATA_EH_ENABLE_LINK);
+			spin_lock_irqsave(ap->lock, flags);
+			link->flags &= ~ATA_LFLAG_DISABLED;
+			spin_unlock_irqrestore(ap->lock, flags);
+			ata_eh_done(link, NULL, ATA_EH_ENABLE_LINK);
+		}
+
 		ata_link_for_each_dev(dev, link) {
 			if (link->flags & ATA_LFLAG_NO_RETRY)
 				ehc->tries[dev->devno] = 1;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index adeee73..2bd1d26 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -170,6 +170,7 @@ enum {
 	ATA_LFLAG_ASSUME_SEMB	= (1 << 4), /* assume SEMB class */
 	ATA_LFLAG_ASSUME_CLASS	= ATA_LFLAG_ASSUME_ATA | ATA_LFLAG_ASSUME_SEMB,
 	ATA_LFLAG_NO_RETRY	= (1 << 5), /* don't retry this link */
+	ATA_LFLAG_DISABLED	= (1 << 6), /* link is disabled */
 
 	/* struct ata_port flags */
 	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */
@@ -289,6 +290,7 @@ enum {
 	ATA_EH_REVALIDATE	= (1 << 0),
 	ATA_EH_SOFTRESET	= (1 << 1),
 	ATA_EH_HARDRESET	= (1 << 2),
+	ATA_EH_ENABLE_LINK	= (1 << 3),
 
 	ATA_EH_RESET_MASK	= ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
 	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE,
@@ -999,6 +1001,7 @@ static inline void ata_ehi_hotplugged(struct ata_eh_info *ehi)
 {
 	ata_ehi_schedule_probe(ehi);
 	ehi->flags |= ATA_EHI_HOTPLUGGED;
+	ehi->action |= ATA_EH_ENABLE_LINK;
 	ehi->err_mask |= AC_ERR_ATA_BUS;
 }
 
-- 
1.5.0.3

[PATCH 12/12] libata-pmp-prep: implement sata_async_notification()

[Tejun Heo]

AN serves multiple purposes.  For ATAPI, it's used for media change
notification.  For PMP, for downstream PHY status change notification.
Implement sata_async_notification() which demultiplexes AN.

To avoid unnecessary port events, ATAPI AN is not enabled if PMP is
attached but SNTF is not available.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Kriten Carlson Accardi <kristen.c.accardi@intel.com>
---
 drivers/ata/ahci.c        |   24 ++++----------
 drivers/ata/libata-core.c |   13 +++++--
 drivers/ata/libata-eh.c   |   73 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/ata/libata-scsi.c |    1 -
 drivers/ata/libata.h      |    1 +
 drivers/ata/sata_sil24.c  |    5 +--
 include/linux/libata.h    |    4 +-
 7 files changed, 93 insertions(+), 28 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index cf34044..9f3c591 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1356,27 +1356,17 @@ static void ahci_port_intr(struct ata_port *ap)
 	}
 
 	if (status & PORT_IRQ_SDB_FIS) {
-		/*
-		 * if this is an ATAPI device with AN turned on,
-		 * then we should interrogate the device to
-		 * determine the cause of the interrupt
-		 *
-		 * for AN - this we should check the SDB FIS
-		 * and find the I and N bits set
+		/* If the 'N' bit in word 0 of the FIS is set, we just
+		 * received asynchronous notification.  Tell libata
+		 * about it.  Note that as the SDB FIS itself is
+		 * accessible, SNotification can be emulated by the
+		 * driver but don't bother for the time being.
 		 */
 		const __le32 *f = pp->rx_fis + RX_FIS_SDB;
 		u32 f0 = le32_to_cpu(f[0]);
 
-		/* check the 'N' bit in word 0 of the FIS */
-		if (f0 & (1 << 15)) {
-			int port_addr = ((f0 & 0x00000f00) >> 8);
-			struct ata_device *adev;
-			if (port_addr < ATA_MAX_DEVICES) {
-				adev = &ap->link.device[port_addr];
-				if (adev->flags & ATA_DFLAG_AN)
-					ata_scsi_media_change_notify(adev);
-			}
-		}
+		if (f0 & (1 << 15))
+			sata_async_notification(ap);
 	}
 
 	if (ap->link.sactive)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 86ef06e..e650fb9 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2018,6 +2018,7 @@ int ata_dev_configure(struct ata_device *dev)
 	else if (dev->class == ATA_DEV_ATAPI) {
 		const char *cdb_intr_string = "";
 		const char *atapi_an_string = "";
+		u32 sntf;
 
 		rc = atapi_cdb_len(id);
 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
@@ -2029,11 +2030,14 @@ int ata_dev_configure(struct ata_device *dev)
 		}
 		dev->cdb_len = (unsigned int) rc;
 
-		/*
-		 * check to see if this ATAPI device supports
-		 * Asynchronous Notification
+		/* Enable ATAPI AN if both the host and device have
+		 * the support.  If PMP is attached, SNTF is required
+		 * to enable ATAPI AN to discern between PHY status
+		 * changed notifications and ATAPI ANs.
 		 */
-		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id)) {
+		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
+		    (!ap->nr_pmp_links ||
+		     sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
 			unsigned int err_mask;
 
 			/* issue SET feature command to turn this on */
@@ -7250,6 +7254,7 @@ EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
 EXPORT_SYMBOL_GPL(ata_link_abort);
 EXPORT_SYMBOL_GPL(ata_port_abort);
 EXPORT_SYMBOL_GPL(ata_port_freeze);
+EXPORT_SYMBOL_GPL(sata_async_notification);
 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 3c31e10..60186f8 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -905,6 +905,79 @@ int ata_port_freeze(struct ata_port *ap)
 }
 
 /**
+ *	sata_async_notification - SATA async notification handler
+ *	@ap: ATA port where async notification is received
+ *
+ *	Handler to be called when async notification via SDB FIS is
+ *	received.  This function schedules EH if necessary.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ *
+ *	RETURNS:
+ *	1 if EH is scheduled, 0 otherwise.
+ */
+int sata_async_notification(struct ata_port *ap)
+{
+	u32 sntf;
+	int rc;
+
+	if (!(ap->flags & ATA_FLAG_AN))
+		return 0;
+
+	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
+	if (rc == 0)
+		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
+
+	if (!ap->nr_pmp_links || rc) {
+		/* PMP is not attached or SNTF is not available */
+		if (!ap->nr_pmp_links) {
+			/* PMP is not attached.  Check whether ATAPI
+			 * AN is configured.  If so, notify media
+			 * change.
+			 */
+			struct ata_device *dev = ap->link.device;
+
+			if ((dev->class == ATA_DEV_ATAPI) &&
+			    (dev->flags & ATA_DFLAG_AN))
+				ata_scsi_media_change_notify(dev);
+			return 0;
+		} else {
+			/* PMP is attached but SNTF is not available.
+			 * ATAPI async media change notification is
+			 * not used.  The PMP must be reporting PHY
+			 * status change, schedule EH.
+			 */
+			ata_port_schedule_eh(ap);
+			return 1;
+		}
+	} else {
+		/* PMP is attached and SNTF is available */
+		struct ata_link *link;
+
+		/* check and notify ATAPI AN */
+		ata_port_for_each_link(link, ap) {
+			if (!(sntf & (1 << link->pmp)))
+				continue;
+
+			if ((link->device->class == ATA_DEV_ATAPI) &&
+			    (link->device->flags & ATA_DFLAG_AN))
+				ata_scsi_media_change_notify(link->device);
+		}
+
+		/* If PMP is reporting that PHY status of some
+		 * downstream ports has changed, schedule EH.
+		 */
+		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
+			ata_port_schedule_eh(ap);
+			return 1;
+		}
+
+		return 0;
+	}
+}
+
+/**
  *	ata_eh_freeze_port - EH helper to freeze port
  *	@ap: ATA port to freeze
  *
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index a651bdd..116d875 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3167,7 +3167,6 @@ void ata_scsi_media_change_notify(struct ata_device *dev)
 		scsi_device_event_notify(dev->sdev, SDEV_MEDIA_CHANGE);
 #endif
 }
-EXPORT_SYMBOL_GPL(ata_scsi_media_change_notify);
 
 /**
  *	ata_scsi_hotplug - SCSI part of hotplug
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index e380423..fc8a786 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -118,6 +118,7 @@ extern int ata_scsi_add_hosts(struct ata_host *host,
 			      struct scsi_host_template *sht);
 extern void ata_scsi_scan_host(struct ata_port *ap, int sync);
 extern int ata_scsi_offline_dev(struct ata_device *dev);
+extern void ata_scsi_media_change_notify(struct ata_device *dev);
 extern void ata_scsi_hotplug(struct work_struct *work);
 extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,
 			       unsigned int buflen);
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index 9acfce4..b4f81eb 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -821,11 +821,8 @@ static void sil24_error_intr(struct ata_port *ap)
 	ata_ehi_push_desc(ehi, "irq_stat 0x%08x", irq_stat);
 
 	if (irq_stat & PORT_IRQ_SDB_NOTIFY) {
-		struct ata_device *dev = ap->link.device;
-
 		ata_ehi_push_desc(ehi, "SDB notify");
-		if (dev->flags & ATA_DFLAG_AN)
-			ata_scsi_media_change_notify(dev);
+		sata_async_notification(ap);
 	}
 
 	if (irq_stat & (PORT_IRQ_PHYRDY_CHG | PORT_IRQ_DEV_XCHG)) {
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 56b2187..cd9c2a2 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -139,7 +139,7 @@ enum {
 	ATA_DFLAG_FLUSH_EXT	= (1 << 4), /* do FLUSH_EXT instead of FLUSH */
 	ATA_DFLAG_ACPI_PENDING	= (1 << 5), /* ACPI resume action pending */
 	ATA_DFLAG_ACPI_FAILED	= (1 << 6), /* ACPI on devcfg has failed */
-	ATA_DFLAG_AN		= (1 << 7), /* device supports AN */
+	ATA_DFLAG_AN		= (1 << 7), /* AN configured */
 	ATA_DFLAG_CFG_MASK	= (1 << 12) - 1,
 
 	ATA_DFLAG_PIO		= (1 << 12), /* device limited to PIO mode */
@@ -787,7 +787,6 @@ extern void ata_host_init(struct ata_host *, struct device *,
 extern int ata_scsi_detect(struct scsi_host_template *sht);
 extern int ata_scsi_ioctl(struct scsi_device *dev, int cmd, void __user *arg);
 extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *));
-extern void ata_scsi_media_change_notify(struct ata_device *atadev);
 extern void ata_sas_port_destroy(struct ata_port *);
 extern struct ata_port *ata_sas_port_alloc(struct ata_host *,
 					   struct ata_port_info *, struct Scsi_Host *);
@@ -953,6 +952,7 @@ extern void ata_port_schedule_eh(struct ata_port *ap);
 extern int ata_link_abort(struct ata_link *link);
 extern int ata_port_abort(struct ata_port *ap);
 extern int ata_port_freeze(struct ata_port *ap);
+extern int sata_async_notification(struct ata_port *ap);
 
 extern void ata_eh_freeze_port(struct ata_port *ap);
 extern void ata_eh_thaw_port(struct ata_port *ap);
-- 
1.5.0.3

[PATCH 10/12] libata-pmp-prep: implement EH fast-fail path

[Tejun Heo]

If PMP itself becomes inaccessible while trying to link a downstream
link, spending time to recover the downstream link doesn't make any
sense.  Make EH skip retry and fail fast if -ERESTART is received.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-eh.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index fbbf791..3c31e10 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2050,7 +2050,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	if (rc == -EAGAIN)
 		rc = 0;
 
-	if (rc && try < ARRAY_SIZE(ata_eh_reset_timeouts)) {
+	if (rc && rc != -ERESTART && try < ARRAY_SIZE(ata_eh_reset_timeouts)) {
 		unsigned long now = jiffies;
 
 		if (time_before(now, deadline)) {
-- 
1.5.0.3

Re: [PATCH 01/12] libata: misc updates for AN

[Jeff Garzik]

Tejun Heo wrote:
> Update AN support in preparation of PMP support.
> 
> * s/ata_id_has_AN/ata_id_has_atapi_AN/
> * add AN enabled reporting during configuration
> * add err_mask to AN configuration failure reporting
> * update LOCKING comment for ata_scsi_media_change_notify()
> * check whether ATA dev is attached to SCSI dev ata_scsi_media_change_notify()
> * set ATA_FLAG_AN in ahci and sata_sil24
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>
> Cc: Kriten Carlson Accardi <kristen.c.accardi@intel.com>
> ---
>  drivers/ata/ahci.c        |    2 +-
>  drivers/ata/libata-core.c |   24 ++++++++++++++----------
>  drivers/ata/libata-scsi.c |    7 ++++---
>  drivers/ata/sata_sil24.c  |   13 +++++++++++--
>  include/linux/ata.h       |    2 +-
>  5 files changed, 31 insertions(+), 17 deletions(-)

applied 1-12