[PATCH 04/10] libata-pm: hook PM support and enable it

[Tejun Heo <htejun@gmail.com>]

Hook PM support into libata and enable it.  Connect SCR and probing
functions, and update ata_dev_classify() to detect PM.

---

 drivers/scsi/libata-core.c |   92 ++++++++++++++++++++++++++++++--------------
 drivers/scsi/libata-eh.c   |   15 +++++++
 2 files changed, 78 insertions(+), 29 deletions(-)

281a766bd690af3ec5d29fcdba68c59ce6e0186b
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 133a6e6..2cea289 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -542,29 +542,46 @@ static unsigned int ata_devchk(struct at
  *	None.
  *
  *	RETURNS:
- *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, or %ATA_DEV_UNKNOWN
- *	the event of failure.
+ *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PM or
+ *	%ATA_DEV_UNKNOWN the event of failure.
  */
-
 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
 {
 	/* Apple's open source Darwin code hints that some devices only
 	 * put a proper signature into the LBA mid/high registers,
 	 * So, we only check those.  It's sufficient for uniqueness.
+	 *
+	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
+	 * signatures for ATA and ATAPI devices attached on SerialATA,
+	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
+	 * spec has never mentioned about using different signatures
+	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
+	 * Multiplier specification began to use 0x69/0x96 to identify
+	 * port multpliers.  ATA/ATAPI-7 dropped descriptions about
+	 * 0x3c/0xc3 and 0x69/0x96 shortly and described them as
+	 * reserved for SerialATA.
+	 *
+	 * We follow the current spec and consider that 0x69/0x96
+	 * identifies a port multiplier.  If there is an ATAPI device
+	 * which returns 0x69/0x96 as its signature, we'll have to
+	 * implement 'try PM, then try ATAPI' logic.
 	 */
-
 	if (((tf->lbam == 0) && (tf->lbah == 0)) ||
 	    ((tf->lbam == 0x3c) && (tf->lbah == 0xc3))) {
 		DPRINTK("found ATA device by sig\n");
 		return ATA_DEV_ATA;
 	}
 
-	if (((tf->lbam == 0x14) && (tf->lbah == 0xeb)) ||
-	    ((tf->lbam == 0x69) && (tf->lbah == 0x96))) {
+	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
 		DPRINTK("found ATAPI device by sig\n");
 		return ATA_DEV_ATAPI;
 	}
 
+	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
+		DPRINTK("found PM device by sig\n");
+		return ATA_DEV_PM;
+	}
+
 	DPRINTK("unknown device\n");
 	return ATA_DEV_UNKNOWN;
 }
@@ -4851,24 +4868,29 @@ int ata_scr_valid(struct ata_link *link)
  *	@val: Place to store read value
  *
  *	Read SCR register @reg of @link into *@val.  This function is
- *	guaranteed to succeed if the cable type of the port is SATA
- *	and the port implements ->scr_read.
+ *	guaranteed to succeed if @link is ap->link, the cable type of
+ *	the port is SATA and the port implements ->scr_read.
  *
  *	LOCKING:
- *	None.
+ *	None if @link is ap->link.  Kernel thread context otherwise.
  *
  *	RETURNS:
  *	0 on success, negative errno on failure.
  */
 int ata_scr_read(struct ata_link *link, int reg, u32 *val)
 {
-	struct ata_port *ap = link->ap;
+	if (ata_is_host_link(link)) {
+		struct ata_port *ap = link->ap;
 
-	if (ata_scr_valid(link)) {
-		*val = ap->ops->scr_read(ap, reg);
-		return 0;
+		if (ata_scr_valid(link)) {
+			*val = ap->ops->scr_read(ap, reg);
+			return 0;
+		}
+
+		return -EOPNOTSUPP;
 	}
-	return -EOPNOTSUPP;
+
+	return ata_pm_scr_read(link, reg, val);
 }
 
 /**
@@ -4878,24 +4900,29 @@ int ata_scr_read(struct ata_link *link, 
  *	@val: value to write
  *
  *	Write @val to SCR register @reg of @link.  This function is
- *	guaranteed to succeed if the cable type of the port is SATA
- *	and the port implements ->scr_read.
+ *	guaranteed to succeed if @link is ap->link, the cable type of
+ *	the port is SATA and the port implements ->scr_read.
  *
  *	LOCKING:
- *	None.
+ *	None if @link is ap->link.  Kernel thread context otherwise.
  *
  *	RETURNS:
  *	0 on success, negative errno on failure.
  */
 int ata_scr_write(struct ata_link *link, int reg, u32 val)
 {
-	struct ata_port *ap = link->ap;
+	if (ata_is_host_link(link)) {
+		struct ata_port *ap = link->ap;
 
-	if (ata_scr_valid(link)) {
-		ap->ops->scr_write(ap, reg, val);
-		return 0;
+		if (ata_scr_valid(link)) {
+			ap->ops->scr_write(ap, reg, val);
+			return 0;
+		}
+
+		return -EOPNOTSUPP;
 	}
-	return -EOPNOTSUPP;
+
+	return ata_pm_scr_write(link, reg, val);
 }
 
 /**
@@ -4908,21 +4935,26 @@ int ata_scr_write(struct ata_link *link,
  *	function performs flush after writing to the register.
  *
  *	LOCKING:
- *	None.
+ *	None if @link is ap->link.  Kernel thread context otherwise.
  *
  *	RETURNS:
  *	0 on success, negative errno on failure.
  */
 int ata_scr_write_flush(struct ata_link *link, int reg, u32 val)
 {
-	struct ata_port *ap = link->ap;
+	if (ata_is_host_link(link)) {
+		struct ata_port *ap = link->ap;
 
-	if (ata_scr_valid(link)) {
-		ap->ops->scr_write(ap, reg, val);
-		ap->ops->scr_read(ap, reg);
-		return 0;
+		if (ata_scr_valid(link)) {
+			ap->ops->scr_write(ap, reg, val);
+			ap->ops->scr_read(ap, reg);
+			return 0;
+		}
+
+		return -EOPNOTSUPP;
 	}
-	return -EOPNOTSUPP;
+
+	return ata_pm_scr_write(link, reg, val);
 }
 
 /**
@@ -5637,6 +5669,8 @@ int ata_scsi_release(struct Scsi_Host *h
 	ap->ops->port_disable(ap);
 	ata_host_remove(ap, 0);
 
+	kfree(ap->pm_link);
+
 	DPRINTK("EXIT\n");
 	return 1;
 }
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 3ad8c01..0fd35ed 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -1569,6 +1569,8 @@ static int ata_eh_revalidate_and_attach(
 	ata_link_for_each_dev(dev, link) {
 		if (ehc->i.action & ATA_EH_REVALIDATE && ata_dev_enabled(dev) &&
 		    (!ehc->i.dev || ehc->i.dev == dev)) {
+			WARN_ON(dev->class == ATA_DEV_PM);
+
 			if (ata_link_offline(dev->link)) {
 				rc = -EIO;
 				break;
@@ -1586,6 +1588,13 @@ static int ata_eh_revalidate_and_attach(
 			   ata_class_enabled(ehc->classes[dev->devno])) {
 			dev->class = ehc->classes[dev->devno];
 
+			if (dev->class == ATA_DEV_PM) {
+				rc = ata_pm_attach(dev);
+				if (rc)
+					dev->class = ATA_DEV_UNKNOWN;
+				break;
+			}
+
 			rc = ata_dev_read_id(dev, &dev->class, 1, dev->id);
 			if (rc == 0)
 				rc = ata_dev_configure(dev, 1);
@@ -1760,6 +1769,12 @@ int ata_eh_recover(struct ata_port *ap, 
 		if (rc)
 			goto dev_fail;
 
+		/* if PM got attached, return, we don't know what to do */
+		if (link->device->class == ATA_DEV_PM) {
+			ehc->i.action = 0;
+			return 0;
+		}
+
 		/* configure transfer mode if the port has been reset */
 		if (ehc->flags & ATA_EHC_DID_RESET) {
 			rc = ata_set_mode(link, &dev);
-- 
1.2.4