Merge branch 'upstream-2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev

* 'upstream-2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ata_piix: IDE Mode SATA patch for Intel Ibex Peak DeviceIDs
  libata-eh: clear UNIT ATTENTION after reset
  ata_piix: add Hercules EC-900 mini-notebook to ich_laptop short cable list
  libata: reorder ata_device to remove 8 bytes of padding on 64 bits
  [libata] pata_bf54x: Add proper PM operation
  pata_sil680: convert CONFIG_PPC_MERGE to CONFIG_PPC
  libata: Implement disk shock protection support
  [libata] Introduce ata_id_has_unload()
  PATA: RPC now selects HAVE_PATA_PLATFORM for pata platform driver
  ata_piix: drop merged SCR access and use slave_link instead
  libata: implement slave_link
  libata: misc updates to prepare for slave link
  libata: reimplement link iterator
  libata: make SCR access ops per-link

drivers/ata/Kconfig

@@ -663,7 +663,7 @@ config HAVE_PATA_PLATFORM
 
 config PATA_PLATFORM
 	tristate "Generic platform device PATA support"
-	depends on EMBEDDED || ARCH_RPC || PPC || HAVE_PATA_PLATFORM
+	depends on EMBEDDED || PPC || HAVE_PATA_PLATFORM
 	help
 	  This option enables support for generic directly connected ATA
 	  devices commonly found on embedded systems.

drivers/ata/ahci.c

@@ -267,8 +267,8 @@ struct ahci_port_priv {
 					 	 * per PM slot */
 };
 
-static int ahci_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int ahci_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int ahci_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int ahci_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 static unsigned int ahci_qc_issue(struct ata_queued_cmd *qc);
 static bool ahci_qc_fill_rtf(struct ata_queued_cmd *qc);
@@ -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
 };
 
@@ -820,10 +821,10 @@ static unsigned ahci_scr_offset(struct ata_port *ap, unsigned int sc_reg)
 	return 0;
 }
 
-static int ahci_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int ahci_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
-	void __iomem *port_mmio = ahci_port_base(ap);
-	int offset = ahci_scr_offset(ap, sc_reg);
+	void __iomem *port_mmio = ahci_port_base(link->ap);
+	int offset = ahci_scr_offset(link->ap, sc_reg);
 
 	if (offset) {
 		*val = readl(port_mmio + offset);
@@ -832,10 +833,10 @@ static int ahci_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 	return -EINVAL;
 }
 
-static int ahci_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int ahci_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
-	void __iomem *port_mmio = ahci_port_base(ap);
-	int offset = ahci_scr_offset(ap, sc_reg);
+	void __iomem *port_mmio = ahci_port_base(link->ap);
+	int offset = ahci_scr_offset(link->ap, sc_reg);
 
 	if (offset) {
 		writel(val, port_mmio + offset);
@@ -973,7 +974,7 @@ static void ahci_disable_alpm(struct ata_port *ap)
 	writel(PORT_IRQ_PHYRDY, port_mmio + PORT_IRQ_STAT);
 
 	/* go ahead and clean out PhyRdy Change from Serror too */
-	ahci_scr_write(ap, SCR_ERROR, ((1 << 16) | (1 << 18)));
+	ahci_scr_write(&ap->link, SCR_ERROR, ((1 << 16) | (1 << 18)));
 
 	/*
  	 * Clear flag to indicate that we should ignore all PhyRdy
@@ -1937,8 +1938,8 @@ static void ahci_error_intr(struct ata_port *ap, u32 irq_stat)
 	ata_ehi_push_desc(host_ehi, "irq_stat 0x%08x", irq_stat);
 
 	/* AHCI needs SError cleared; otherwise, it might lock up */
-	ahci_scr_read(ap, SCR_ERROR, &serror);
-	ahci_scr_write(ap, SCR_ERROR, serror);
+	ahci_scr_read(&ap->link, SCR_ERROR, &serror);
+	ahci_scr_write(&ap->link, SCR_ERROR, serror);
 	host_ehi->serror |= serror;
 
 	/* some controllers set IRQ_IF_ERR on device errors, ignore it */
@@ -2027,7 +2028,7 @@ static void ahci_port_intr(struct ata_port *ap)
 	if ((hpriv->flags & AHCI_HFLAG_NO_HOTPLUG) &&
 		(status & PORT_IRQ_PHYRDY)) {
 		status &= ~PORT_IRQ_PHYRDY;
-		ahci_scr_write(ap, SCR_ERROR, ((1 << 16) | (1 << 18)));
+		ahci_scr_write(&ap->link, SCR_ERROR, ((1 << 16) | (1 << 18)));
 	}
 
 	if (unlikely(status & PORT_IRQ_ERROR)) {

drivers/ata/ata_piix.c

@@ -165,8 +165,10 @@ static void piix_set_dmamode(struct ata_port *ap, struct ata_device *adev);
 static void ich_set_dmamode(struct ata_port *ap, struct ata_device *adev);
 static int ich_pata_cable_detect(struct ata_port *ap);
 static u8 piix_vmw_bmdma_status(struct ata_port *ap);
-static int piix_sidpr_scr_read(struct ata_port *ap, unsigned int reg, u32 *val);
-static int piix_sidpr_scr_write(struct ata_port *ap, unsigned int reg, u32 val);
+static int piix_sidpr_scr_read(struct ata_link *link,
+			       unsigned int reg, u32 *val);
+static int piix_sidpr_scr_write(struct ata_link *link,
+				unsigned int reg, u32 val);
 #ifdef CONFIG_PM
 static int piix_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
 static int piix_pci_device_resume(struct pci_dev *pdev);
@@ -278,12 +280,15 @@ static const struct pci_device_id piix_pci_tbl[] = {
 	/* SATA Controller IDE (PCH) */
 	{ 0x8086, 0x3b20, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
 	/* SATA Controller IDE (PCH) */
+	{ 0x8086, 0x3b21, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_2port_sata },
+	/* SATA Controller IDE (PCH) */
 	{ 0x8086, 0x3b26, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_2port_sata },
 	/* SATA Controller IDE (PCH) */
+	{ 0x8086, 0x3b28, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
+	/* SATA Controller IDE (PCH) */
 	{ 0x8086, 0x3b2d, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_2port_sata },
 	/* SATA Controller IDE (PCH) */
 	{ 0x8086, 0x3b2e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
-
 	{ }	/* terminate list */
 };
 
@@ -582,6 +587,7 @@ static const struct ich_laptop ich_laptop[] = {
 	{ 0x27DF, 0x1025, 0x0110 },	/* ICH7 on Acer 3682WLMi */
 	{ 0x27DF, 0x1043, 0x1267 },	/* ICH7 on Asus W5F */
 	{ 0x27DF, 0x103C, 0x30A1 },	/* ICH7 on HP Compaq nc2400 */
+	{ 0x27DF, 0x1071, 0xD221 },	/* ICH7 on Hercules EC-900 */
 	{ 0x24CA, 0x1025, 0x0061 },	/* ICH4 on ACER Aspire 2023WLMi */
 	{ 0x24CA, 0x1025, 0x003d },	/* ICH4 on ACER TM290 */
 	{ 0x266F, 0x1025, 0x0066 },	/* ICH6 on ACER Aspire 1694WLMi */
@@ -885,23 +891,9 @@ static void ich_set_dmamode(struct ata_port *ap, struct ata_device *adev)
  * Serial ATA Index/Data Pair Superset Registers access
  *
  * Beginning from ICH8, there's a sane way to access SCRs using index
- * and data register pair located at BAR5.  This creates an
- * interesting problem of mapping two SCRs to one port.
- *
- * Although they have separate SCRs, the master and slave aren't
- * independent enough to be treated as separate links - e.g. softreset
- * resets both.  Also, there's no protocol defined for hard resetting
- * singled device sharing the virtual port (no defined way to acquire
- * device signature).  This is worked around by merging the SCR values
- * into one sensible value and requesting follow-up SRST after
- * hardreset.
- *
- * SCR merging is perfomed in nibbles which is the unit contents in
- * SCRs are organized.  If two values are equal, the value is used.
- * When they differ, merge table which lists precedence of possible
- * values is consulted and the first match or the last entry when
- * nothing matches is used.  When there's no merge table for the
- * specific nibble, value from the first port is used.
+ * and data register pair located at BAR5 which means that we have
+ * separate SCRs for master and slave.  This is handled using libata
+ * slave_link facility.
  */
 static const int piix_sidx_map[] = {
 	[SCR_STATUS]	= 0,
@@ -909,120 +901,38 @@ static const int piix_sidx_map[] = {
 	[SCR_CONTROL]	= 1,
 };
 
-static void piix_sidpr_sel(struct ata_device *dev, unsigned int reg)
+static void piix_sidpr_sel(struct ata_link *link, unsigned int reg)
 {
-	struct ata_port *ap = dev->link->ap;
+	struct ata_port *ap = link->ap;
 	struct piix_host_priv *hpriv = ap->host->private_data;
 
-	iowrite32(((ap->port_no * 2 + dev->devno) << 8) | piix_sidx_map[reg],
+	iowrite32(((ap->port_no * 2 + link->pmp) << 8) | piix_sidx_map[reg],
 		  hpriv->sidpr + PIIX_SIDPR_IDX);
 }
 
-static int piix_sidpr_read(struct ata_device *dev, unsigned int reg)
-{
-	struct piix_host_priv *hpriv = dev->link->ap->host->private_data;
-
-	piix_sidpr_sel(dev, reg);
-	return ioread32(hpriv->sidpr + PIIX_SIDPR_DATA);
-}
-
-static void piix_sidpr_write(struct ata_device *dev, unsigned int reg, u32 val)
-{
-	struct piix_host_priv *hpriv = dev->link->ap->host->private_data;
-
-	piix_sidpr_sel(dev, reg);
-	iowrite32(val, hpriv->sidpr + PIIX_SIDPR_DATA);
-}
-
-static u32 piix_merge_scr(u32 val0, u32 val1, const int * const *merge_tbl)
-{
-	u32 val = 0;
-	int i, mi;
-
-	for (i = 0, mi = 0; i < 32 / 4; i++) {
-		u8 c0 = (val0 >> (i * 4)) & 0xf;
-		u8 c1 = (val1 >> (i * 4)) & 0xf;
-		u8 merged = c0;
-		const int *cur;
-
-		/* if no merge preference, assume the first value */
-		cur = merge_tbl[mi];
-		if (!cur)
-			goto done;
-		mi++;
-
-		/* if two values equal, use it */
-		if (c0 == c1)
-			goto done;
-
-		/* choose the first match or the last from the merge table */
-		while (*cur != -1) {
-			if (c0 == *cur || c1 == *cur)
-				break;
-			cur++;
-		}
-		if (*cur == -1)
-			cur--;
-		merged = *cur;
-	done:
-		val |= merged << (i * 4);
-	}
-
-	return val;
-}
-
-static int piix_sidpr_scr_read(struct ata_port *ap, unsigned int reg, u32 *val)
+static int piix_sidpr_scr_read(struct ata_link *link,
+			       unsigned int reg, u32 *val)
 {
-	const int * const sstatus_merge_tbl[] = {
-		/* DET */ (const int []){ 1, 3, 0, 4, 3, -1 },
-		/* SPD */ (const int []){ 2, 1, 0, -1 },
-		/* IPM */ (const int []){ 6, 2, 1, 0, -1 },
-		NULL,
-	};
-	const int * const scontrol_merge_tbl[] = {
-		/* DET */ (const int []){ 1, 0, 4, 0, -1 },
-		/* SPD */ (const int []){ 0, 2, 1, 0, -1 },
-		/* IPM */ (const int []){ 0, 1, 2, 3, 0, -1 },
-		NULL,
-	};
-	u32 v0, v1;
+	struct piix_host_priv *hpriv = link->ap->host->private_data;
 
 	if (reg >= ARRAY_SIZE(piix_sidx_map))
 		return -EINVAL;
 
-	if (!(ap->flags & ATA_FLAG_SLAVE_POSS)) {
-		*val = piix_sidpr_read(&ap->link.device[0], reg);
-		return 0;
-	}
-
-	v0 = piix_sidpr_read(&ap->link.device[0], reg);
-	v1 = piix_sidpr_read(&ap->link.device[1], reg);
-
-	switch (reg) {
-	case SCR_STATUS:
-		*val = piix_merge_scr(v0, v1, sstatus_merge_tbl);
-		break;
-	case SCR_ERROR:
-		*val = v0 | v1;
-		break;
-	case SCR_CONTROL:
-		*val = piix_merge_scr(v0, v1, scontrol_merge_tbl);
-		break;
-	}
-
+	piix_sidpr_sel(link, reg);
+	*val = ioread32(hpriv->sidpr + PIIX_SIDPR_DATA);
 	return 0;
 }
 
-static int piix_sidpr_scr_write(struct ata_port *ap, unsigned int reg, u32 val)
+static int piix_sidpr_scr_write(struct ata_link *link,
+				unsigned int reg, u32 val)
 {
+	struct piix_host_priv *hpriv = link->ap->host->private_data;
+
 	if (reg >= ARRAY_SIZE(piix_sidx_map))
 		return -EINVAL;
 
-	piix_sidpr_write(&ap->link.device[0], reg, val);
-
-	if (ap->flags & ATA_FLAG_SLAVE_POSS)
-		piix_sidpr_write(&ap->link.device[1], reg, val);
-
+	piix_sidpr_sel(link, reg);
+	iowrite32(val, hpriv->sidpr + PIIX_SIDPR_DATA);
 	return 0;
 }
 
@@ -1363,28 +1273,28 @@ static const int *__devinit piix_init_sata_map(struct pci_dev *pdev,
 	return map;
 }
 
-static void __devinit piix_init_sidpr(struct ata_host *host)
+static int __devinit piix_init_sidpr(struct ata_host *host)
 {
 	struct pci_dev *pdev = to_pci_dev(host->dev);
 	struct piix_host_priv *hpriv = host->private_data;
-	struct ata_device *dev0 = &host->ports[0]->link.device[0];
+	struct ata_link *link0 = &host->ports[0]->link;
 	u32 scontrol;
-	int i;
+	int i, rc;
 
 	/* check for availability */
 	for (i = 0; i < 4; i++)
 		if (hpriv->map[i] == IDE)
-			return;
+			return 0;
 
 	if (!(host->ports[0]->flags & PIIX_FLAG_SIDPR))
-		return;
+		return 0;
 
 	if (pci_resource_start(pdev, PIIX_SIDPR_BAR) == 0 ||
 	    pci_resource_len(pdev, PIIX_SIDPR_BAR) != PIIX_SIDPR_LEN)
-		return;
+		return 0;
 
 	if (pcim_iomap_regions(pdev, 1 << PIIX_SIDPR_BAR, DRV_NAME))
-		return;
+		return 0;
 
 	hpriv->sidpr = pcim_iomap_table(pdev)[PIIX_SIDPR_BAR];
 
@@ -1392,7 +1302,7 @@ static void __devinit piix_init_sidpr(struct ata_host *host)
 	 * Give it a test drive by inhibiting power save modes which
 	 * we'll do anyway.
 	 */
-	scontrol = piix_sidpr_read(dev0, SCR_CONTROL);
+	piix_sidpr_scr_read(link0, SCR_CONTROL, &scontrol);
 
 	/* if IPM is already 3, SCR access is probably working.  Don't
 	 * un-inhibit power save modes as BIOS might have inhibited
@@ -1400,18 +1310,30 @@ static void __devinit piix_init_sidpr(struct ata_host *host)
 	 */
 	if ((scontrol & 0xf00) != 0x300) {
 		scontrol |= 0x300;
-		piix_sidpr_write(dev0, SCR_CONTROL, scontrol);
-		scontrol = piix_sidpr_read(dev0, SCR_CONTROL);
+		piix_sidpr_scr_write(link0, SCR_CONTROL, scontrol);
+		piix_sidpr_scr_read(link0, SCR_CONTROL, &scontrol);
 
 		if ((scontrol & 0xf00) != 0x300) {
 			dev_printk(KERN_INFO, host->dev, "SCR access via "
 				   "SIDPR is available but doesn't work\n");
-			return;
+			return 0;
 		}
 	}
 
-	host->ports[0]->ops = &piix_sidpr_sata_ops;
-	host->ports[1]->ops = &piix_sidpr_sata_ops;
+	/* okay, SCRs available, set ops and ask libata for slave_link */
+	for (i = 0; i < 2; i++) {
+		struct ata_port *ap = host->ports[i];
+
+		ap->ops = &piix_sidpr_sata_ops;
+
+		if (ap->flags & ATA_FLAG_SLAVE_POSS) {
+			rc = ata_slave_link_init(ap);
+			if (rc)
+				return rc;
+		}
+	}
+
+	return 0;
 }
 
 static void piix_iocfg_bit18_quirk(struct pci_dev *pdev)
@@ -1521,7 +1443,9 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
 	/* initialize controller */
 	if (port_flags & ATA_FLAG_SATA) {
 		piix_init_pcs(host, piix_map_db_table[ent->driver_data]);
-		piix_init_sidpr(host);
+		rc = piix_init_sidpr(host);
+		if (rc)
+			return rc;
 	}
 
 	/* apply IOCFG bit18 quirk */

drivers/ata/libata-core.c

@@ -163,6 +163,67 @@ 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 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
@@ -206,7 +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.
@@ -214,12 +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];
@@ -266,9 +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];
@@ -320,9 +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];
@@ -2681,7 +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",
@@ -3372,6 +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;
 
@@ -3593,7 +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;
@@ -3671,7 +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. */
@@ -4868,10 +4935,8 @@ int sata_scr_valid(struct ata_link *link)
 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
 {
 	if (ata_is_host_link(link)) {
-		struct ata_port *ap = link->ap;
-
 		if (sata_scr_valid(link))
-			return ap->ops->scr_read(ap, reg, val);
+			return link->ap->ops->scr_read(link, reg, val);
 		return -EOPNOTSUPP;
 	}
 
@@ -4897,10 +4962,8 @@ int sata_scr_read(struct ata_link *link, int reg, u32 *val)
 int sata_scr_write(struct ata_link *link, int reg, u32 val)
 {
 	if (ata_is_host_link(link)) {
-		struct ata_port *ap = link->ap;
-
 		if (sata_scr_valid(link))
-			return ap->ops->scr_write(ap, reg, val);
+			return link->ap->ops->scr_write(link, reg, val);
 		return -EOPNOTSUPP;
 	}
 
@@ -4925,13 +4988,12 @@ int sata_scr_write(struct ata_link *link, int reg, u32 val)
 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
 {
 	if (ata_is_host_link(link)) {
-		struct ata_port *ap = link->ap;
 		int rc;
 
 		if (sata_scr_valid(link)) {
-			rc = ap->ops->scr_write(ap, reg, val);
+			rc = link->ap->ops->scr_write(link, reg, val);
 			if (rc == 0)
-				rc = ap->ops->scr_read(ap, reg, &val);
+				rc = link->ap->ops->scr_read(link, reg, &val);
 			return rc;
 		}
 		return -EOPNOTSUPP;
@@ -4941,7 +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
@@ -4952,20 +5014,20 @@ 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_phys_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;
 }
 
 /**
- *	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
@@ -4976,16 +5038,68 @@ 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_phys_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;
+}
+
+/**
+ *	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
@@ -5127,11 +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;
 
@@ -5264,6 +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;
@@ -5294,6 +5409,7 @@ 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;
 	}
@@ -5414,6 +5530,68 @@ 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);
@@ -5640,6 +5818,8 @@ 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,
@@ -6260,10 +6440,12 @@ 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);
 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);

drivers/ata/libata-eh.c

@@ -79,6 +79,8 @@ enum {
 	 */
 	ATA_EH_PRERESET_TIMEOUT		= 10000,
 	ATA_EH_FASTDRAIN_INTERVAL	=  3000,
+
+	ATA_EH_UA_TRIES			= 5,
 };
 
 /* The following table determines how we sequence resets.  Each entry
@@ -1356,6 +1358,37 @@ static int ata_eh_read_log_10h(struct ata_device *dev,
 	return 0;
 }
 
+/**
+ *	atapi_eh_tur - perform ATAPI TEST_UNIT_READY
+ *	@dev: target ATAPI device
+ *	@r_sense_key: out parameter for sense_key
+ *
+ *	Perform ATAPI TEST_UNIT_READY.
+ *
+ *	LOCKING:
+ *	EH context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, AC_ERR_* mask on failure.
+ */
+static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
+{
+	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+
+	ata_tf_init(dev, &tf);
+
+	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
+	tf.command = ATA_CMD_PACKET;
+	tf.protocol = ATAPI_PROT_NODATA;
+
+	err_mask = ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
+	if (err_mask == AC_ERR_DEV)
+		*r_sense_key = tf.feature >> 4;
+	return err_mask;
+}
+
 /**
  *	atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
  *	@dev: device to perform REQUEST_SENSE to
@@ -1756,7 +1789,7 @@ 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 +1913,8 @@ 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 +2001,23 @@ 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 +2052,8 @@ 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 +2120,7 @@ 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 +2212,14 @@ 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 +2241,20 @@ 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 +2309,30 @@ 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 +2381,51 @@ 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 +2446,7 @@ 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 +2459,8 @@ 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 +2473,17 @@ 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 +2493,21 @@ 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 +2518,8 @@ 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 +2527,8 @@ 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 +2549,7 @@ 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));
 
@@ -2439,13 +2557,92 @@ 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;
 }
 
+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)
 {
@@ -2472,7 +2669,7 @@ 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;
 			}
@@ -2610,6 +2807,53 @@ int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
 	return rc;
 }
 
+/**
+ *	atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
+ *	@dev: ATAPI device to clear UA for
+ *
+ *	Resets and other operations can make an ATAPI device raise
+ *	UNIT ATTENTION which causes the next operation to fail.  This
+ *	function clears UA.
+ *
+ *	LOCKING:
+ *	EH context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+static int atapi_eh_clear_ua(struct ata_device *dev)
+{
+	int i;
+
+	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
+		u8 sense_buffer[SCSI_SENSE_BUFFERSIZE];
+		u8 sense_key = 0;
+		unsigned int err_mask;
+
+		err_mask = atapi_eh_tur(dev, &sense_key);
+		if (err_mask != 0 && err_mask != AC_ERR_DEV) {
+			ata_dev_printk(dev, KERN_WARNING, "TEST_UNIT_READY "
+				"failed (err_mask=0x%x)\n", err_mask);
+			return -EIO;
+		}
+
+		if (!err_mask || sense_key != UNIT_ATTENTION)
+			return 0;
+
+		err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
+		if (err_mask) {
+			ata_dev_printk(dev, KERN_WARNING, "failed to clear "
+				"UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
+			return -EIO;
+		}
+	}
+
+	ata_dev_printk(dev, KERN_WARNING,
+		"UNIT ATTENTION persists after %d tries\n", ATA_EH_UA_TRIES);
+
+	return 0;
+}
+
 static int ata_link_nr_enabled(struct ata_link *link)
 {
 	struct ata_device *dev;
@@ -2697,7 +2941,7 @@ 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 +2951,7 @@ 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 */
@@ -2755,7 +2999,7 @@ 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");
 
@@ -2829,6 +3073,56 @@ 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;
@@ -2852,6 +3146,20 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 			ehc->i.flags &= ~ATA_EHI_SETMODE;
 		}
 
+		/* If reset has been issued, clear UA to avoid
+		 * disrupting the current users of the device.
+		 */
+		if (ehc->i.flags & ATA_EHI_DID_RESET) {
+			ata_link_for_each_dev(dev, link) {
+				if (dev->class != ATA_DEV_ATAPI)
+					continue;
+				rc = atapi_eh_clear_ua(dev);
+				if (rc)
+					goto dev_fail;
+			}
+		}
+
+		/* configure link power saving */
 		if (ehc->i.action & ATA_EH_LPM)
 			ata_link_for_each_dev(dev, link)
 				ata_dev_enable_pm(dev, ap->pm_policy);

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);
 

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);

drivers/ata/pata_bf54x.c

@@ -1632,6 +1632,8 @@ static int __devinit bfin_atapi_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	dev_set_drvdata(&pdev->dev, host);
+
 	return 0;
 }
 
@@ -1648,6 +1650,7 @@ static int __devexit bfin_atapi_remove(struct platform_device *pdev)
 	struct ata_host *host = dev_get_drvdata(dev);
 
 	ata_host_detach(host);
+	dev_set_drvdata(&pdev->dev, NULL);
 
 	peripheral_free_list(atapi_io_port);
 
@@ -1655,27 +1658,44 @@ static int __devexit bfin_atapi_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM
-int bfin_atapi_suspend(struct platform_device *pdev, pm_message_t state)
+static int bfin_atapi_suspend(struct platform_device *pdev, pm_message_t state)
 {
-	return 0;
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	if (host)
+		return ata_host_suspend(host, state);
+	else
+		return 0;
 }
 
-int bfin_atapi_resume(struct platform_device *pdev)
+static int bfin_atapi_resume(struct platform_device *pdev)
 {
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	int ret;
+
+	if (host) {
+		ret = bfin_reset_controller(host);
+		if (ret) {
+			printk(KERN_ERR DRV_NAME ": Error during HW init\n");
+			return ret;
+		}
+		ata_host_resume(host);
+	}
+
 	return 0;
 }
+#else
+#define bfin_atapi_suspend NULL
+#define bfin_atapi_resume NULL
 #endif
 
 static struct platform_driver bfin_atapi_driver = {
 	.probe			= bfin_atapi_probe,
 	.remove			= __devexit_p(bfin_atapi_remove),
+	.suspend		= bfin_atapi_suspend,
+	.resume			= bfin_atapi_resume,
 	.driver = {
 		.name		= DRV_NAME,
 		.owner		= THIS_MODULE,
-#ifdef CONFIG_PM
-		.suspend	= bfin_atapi_suspend,
-		.resume		= bfin_atapi_resume,
-#endif
 	},
 };
 

drivers/ata/pata_sil680.c

@@ -230,7 +230,7 @@ static u8 sil680_init_chip(struct pci_dev *pdev, int *try_mmio)
 		tmpbyte & 1, tmpbyte & 0x30);
 
 	*try_mmio = 0;
-#ifdef CONFIG_PPC_MERGE
+#ifdef CONFIG_PPC
 	if (machine_is(cell))
 		*try_mmio = (tmpbyte & 1) || pci_resource_start(pdev, 5);
 #endif

drivers/ata/sata_fsl.c

@@ -469,10 +469,10 @@ static bool sata_fsl_qc_fill_rtf(struct ata_queued_cmd *qc)
 	return true;
 }
 
-static int sata_fsl_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
-			       u32 val)
+static int sata_fsl_scr_write(struct ata_link *link,
+			      unsigned int sc_reg_in, u32 val)
 {
-	struct sata_fsl_host_priv *host_priv = ap->host->private_data;
+	struct sata_fsl_host_priv *host_priv = link->ap->host->private_data;
 	void __iomem *ssr_base = host_priv->ssr_base;
 	unsigned int sc_reg;
 
@@ -493,10 +493,10 @@ static int sata_fsl_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
 	return 0;
 }
 
-static int sata_fsl_scr_read(struct ata_port *ap, unsigned int sc_reg_in,
-			u32 *val)
+static int sata_fsl_scr_read(struct ata_link *link,
+			     unsigned int sc_reg_in, u32 *val)
 {
-	struct sata_fsl_host_priv *host_priv = ap->host->private_data;
+	struct sata_fsl_host_priv *host_priv = link->ap->host->private_data;
 	void __iomem *ssr_base = host_priv->ssr_base;
 	unsigned int sc_reg;
 
@@ -645,12 +645,12 @@ static int sata_fsl_port_start(struct ata_port *ap)
 	 * Workaround for 8315DS board 3gbps link-up issue,
 	 * currently limit SATA port to GEN1 speed
 	 */
-	sata_fsl_scr_read(ap, SCR_CONTROL, &temp);
+	sata_fsl_scr_read(&ap->link, SCR_CONTROL, &temp);
 	temp &= ~(0xF << 4);
 	temp |= (0x1 << 4);
-	sata_fsl_scr_write(ap, SCR_CONTROL, temp);
+	sata_fsl_scr_write(&ap->link, SCR_CONTROL, temp);
 
-	sata_fsl_scr_read(ap, SCR_CONTROL, &temp);
+	sata_fsl_scr_read(&ap->link, SCR_CONTROL, &temp);
 	dev_printk(KERN_WARNING, dev, "scr_control, speed limited to %x\n",
 			temp);
 #endif
@@ -868,7 +868,7 @@ issue_srst:
 			ioread32(CQ + hcr_base),
 			ioread32(CA + hcr_base), ioread32(CC + hcr_base));
 
-		sata_fsl_scr_read(ap, SCR_ERROR, &Serror);
+		sata_fsl_scr_read(&ap->link, SCR_ERROR, &Serror);
 
 		DPRINTK("HStatus = 0x%x\n", ioread32(hcr_base + HSTATUS));
 		DPRINTK("HControl = 0x%x\n", ioread32(hcr_base + HCONTROL));
@@ -972,9 +972,9 @@ static void sata_fsl_error_intr(struct ata_port *ap)
 	 * Handle & Clear SError
 	 */
 
-	sata_fsl_scr_read(ap, SCR_ERROR, &SError);
+	sata_fsl_scr_read(&ap->link, SCR_ERROR, &SError);
 	if (unlikely(SError & 0xFFFF0000)) {
-		sata_fsl_scr_write(ap, SCR_ERROR, SError);
+		sata_fsl_scr_write(&ap->link, SCR_ERROR, SError);
 	}
 
 	DPRINTK("error_intr,hStat=0x%x,CE=0x%x,DE =0x%x,SErr=0x%x\n",
@@ -1091,7 +1091,7 @@ static void sata_fsl_host_intr(struct ata_port *ap)
 
 	hstatus = ioread32(hcr_base + HSTATUS);
 
-	sata_fsl_scr_read(ap, SCR_ERROR, &SError);
+	sata_fsl_scr_read(&ap->link, SCR_ERROR, &SError);
 
 	if (unlikely(SError & 0xFFFF0000)) {
 		DPRINTK("serror @host_intr : 0x%x\n", SError);

drivers/ata/sata_inic162x.c

@@ -269,9 +269,9 @@ static void inic_reset_port(void __iomem *port_base)
 	writeb(0xff, port_base + PORT_IRQ_STAT);
 }
 
-static int inic_scr_read(struct ata_port *ap, unsigned sc_reg, u32 *val)
+static int inic_scr_read(struct ata_link *link, unsigned sc_reg, u32 *val)
 {
-	void __iomem *scr_addr = inic_port_base(ap) + PORT_SCR;
+	void __iomem *scr_addr = inic_port_base(link->ap) + PORT_SCR;
 	void __iomem *addr;
 
 	if (unlikely(sc_reg >= ARRAY_SIZE(scr_map)))
@@ -286,9 +286,9 @@ static int inic_scr_read(struct ata_port *ap, unsigned sc_reg, u32 *val)
 	return 0;
 }
 
-static int inic_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val)
+static int inic_scr_write(struct ata_link *link, unsigned sc_reg, u32 val)
 {
-	void __iomem *scr_addr = inic_port_base(ap) + PORT_SCR;
+	void __iomem *scr_addr = inic_port_base(link->ap) + PORT_SCR;
 
 	if (unlikely(sc_reg >= ARRAY_SIZE(scr_map)))
 		return -EINVAL;

drivers/ata/sata_mv.c

@@ -493,10 +493,10 @@ struct mv_hw_ops {
 	void (*reset_bus)(struct ata_host *host, void __iomem *mmio);
 };
 
-static int mv_scr_read(struct ata_port *ap, unsigned int sc_reg_in, u32 *val);
-static int mv_scr_write(struct ata_port *ap, unsigned int sc_reg_in, u32 val);
-static int mv5_scr_read(struct ata_port *ap, unsigned int sc_reg_in, u32 *val);
-static int mv5_scr_write(struct ata_port *ap, unsigned int sc_reg_in, u32 val);
+static int mv_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val);
+static int mv_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val);
+static int mv5_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val);
+static int mv5_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val);
 static int mv_port_start(struct ata_port *ap);
 static void mv_port_stop(struct ata_port *ap);
 static int mv_qc_defer(struct ata_queued_cmd *qc);
@@ -1070,23 +1070,23 @@ static unsigned int mv_scr_offset(unsigned int sc_reg_in)
 	return ofs;
 }
 
-static int mv_scr_read(struct ata_port *ap, unsigned int sc_reg_in, u32 *val)
+static int mv_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val)
 {
 	unsigned int ofs = mv_scr_offset(sc_reg_in);
 
 	if (ofs != 0xffffffffU) {
-		*val = readl(mv_ap_base(ap) + ofs);
+		*val = readl(mv_ap_base(link->ap) + ofs);
 		return 0;
 	} else
 		return -EINVAL;
 }
 
-static int mv_scr_write(struct ata_port *ap, unsigned int sc_reg_in, u32 val)
+static int mv_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val)
 {
 	unsigned int ofs = mv_scr_offset(sc_reg_in);
 
 	if (ofs != 0xffffffffU) {
-		writelfl(val, mv_ap_base(ap) + ofs);
+		writelfl(val, mv_ap_base(link->ap) + ofs);
 		return 0;
 	} else
 		return -EINVAL;
@@ -2251,11 +2251,11 @@ static unsigned int mv5_scr_offset(unsigned int sc_reg_in)
 	return ofs;
 }
 
-static int mv5_scr_read(struct ata_port *ap, unsigned int sc_reg_in, u32 *val)
+static int mv5_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val)
 {
-	struct mv_host_priv *hpriv = ap->host->private_data;
+	struct mv_host_priv *hpriv = link->ap->host->private_data;
 	void __iomem *mmio = hpriv->base;
-	void __iomem *addr = mv5_phy_base(mmio, ap->port_no);
+	void __iomem *addr = mv5_phy_base(mmio, link->ap->port_no);
 	unsigned int ofs = mv5_scr_offset(sc_reg_in);
 
 	if (ofs != 0xffffffffU) {
@@ -2265,11 +2265,11 @@ static int mv5_scr_read(struct ata_port *ap, unsigned int sc_reg_in, u32 *val)
 		return -EINVAL;
 }
 
-static int mv5_scr_write(struct ata_port *ap, unsigned int sc_reg_in, u32 val)
+static int mv5_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val)
 {
-	struct mv_host_priv *hpriv = ap->host->private_data;
+	struct mv_host_priv *hpriv = link->ap->host->private_data;
 	void __iomem *mmio = hpriv->base;
-	void __iomem *addr = mv5_phy_base(mmio, ap->port_no);
+	void __iomem *addr = mv5_phy_base(mmio, link->ap->port_no);
 	unsigned int ofs = mv5_scr_offset(sc_reg_in);
 
 	if (ofs != 0xffffffffU) {

drivers/ata/sata_nv.c

@@ -302,8 +302,8 @@ static void nv_ck804_host_stop(struct ata_host *host);
 static irqreturn_t nv_generic_interrupt(int irq, void *dev_instance);
 static irqreturn_t nv_nf2_interrupt(int irq, void *dev_instance);
 static irqreturn_t nv_ck804_interrupt(int irq, void *dev_instance);
-static int nv_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int nv_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int nv_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int nv_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 
 static void nv_nf2_freeze(struct ata_port *ap);
 static void nv_nf2_thaw(struct ata_port *ap);
@@ -1511,21 +1511,21 @@ static irqreturn_t nv_ck804_interrupt(int irq, void *dev_instance)
 	return ret;
 }
 
-static int nv_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int nv_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
 
-	*val = ioread32(ap->ioaddr.scr_addr + (sc_reg * 4));
+	*val = ioread32(link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 
-static int nv_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int nv_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
 
-	iowrite32(val, ap->ioaddr.scr_addr + (sc_reg * 4));
+	iowrite32(val, link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 
@@ -2218,9 +2218,9 @@ static void nv_swncq_host_interrupt(struct ata_port *ap, u16 fis)
 	if (!pp->qc_active)
 		return;
 
-	if (ap->ops->scr_read(ap, SCR_ERROR, &serror))
+	if (ap->ops->scr_read(&ap->link, SCR_ERROR, &serror))
 		return;
-	ap->ops->scr_write(ap, SCR_ERROR, serror);
+	ap->ops->scr_write(&ap->link, SCR_ERROR, serror);
 
 	if (ata_stat & ATA_ERR) {
 		ata_ehi_clear_desc(ehi);

drivers/ata/sata_promise.c

@@ -137,8 +137,8 @@ struct pdc_port_priv {
 	dma_addr_t		pkt_dma;
 };
 
-static int pdc_sata_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int pdc_sata_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int pdc_sata_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int pdc_sata_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static int pdc_ata_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 static int pdc_common_port_start(struct ata_port *ap);
 static int pdc_sata_port_start(struct ata_port *ap);
@@ -386,19 +386,21 @@ static int pdc_sata_cable_detect(struct ata_port *ap)
 	return ATA_CBL_SATA;
 }
 
-static int pdc_sata_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int pdc_sata_scr_read(struct ata_link *link,
+			     unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	*val = readl(ap->ioaddr.scr_addr + (sc_reg * 4));
+	*val = readl(link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 
-static int pdc_sata_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int pdc_sata_scr_write(struct ata_link *link,
+			      unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	writel(val, ap->ioaddr.scr_addr + (sc_reg * 4));
+	writel(val, link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 
@@ -731,7 +733,7 @@ static void pdc_error_intr(struct ata_port *ap, struct ata_queued_cmd *qc,
 	if (sata_scr_valid(&ap->link)) {
 		u32 serror;
 
-		pdc_sata_scr_read(ap, SCR_ERROR, &serror);
+		pdc_sata_scr_read(&ap->link, SCR_ERROR, &serror);
 		ehi->serror |= serror;
 	}
 

drivers/ata/sata_qstor.c

@@ -111,8 +111,8 @@ struct qs_port_priv {
 	qs_state_t		state;
 };
 
-static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int qs_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int qs_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int qs_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static int qs_ata_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 static int qs_port_start(struct ata_port *ap);
 static void qs_host_stop(struct ata_host *host);
@@ -242,11 +242,11 @@ static int qs_prereset(struct ata_link *link, unsigned long deadline)
 	return ata_sff_prereset(link, deadline);
 }
 
-static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int qs_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	*val = readl(ap->ioaddr.scr_addr + (sc_reg * 8));
+	*val = readl(link->ap->ioaddr.scr_addr + (sc_reg * 8));
 	return 0;
 }
 
@@ -256,11 +256,11 @@ static void qs_error_handler(struct ata_port *ap)
 	ata_std_error_handler(ap);
 }
 
-static int qs_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int qs_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	writel(val, ap->ioaddr.scr_addr + (sc_reg * 8));
+	writel(val, link->ap->ioaddr.scr_addr + (sc_reg * 8));
 	return 0;
 }
 

drivers/ata/sata_sil.c

@@ -115,8 +115,8 @@ static int sil_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 static int sil_pci_device_resume(struct pci_dev *pdev);
 #endif
 static void sil_dev_config(struct ata_device *dev);
-static int sil_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int sil_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int sil_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int sil_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static int sil_set_mode(struct ata_link *link, struct ata_device **r_failed);
 static void sil_freeze(struct ata_port *ap);
 static void sil_thaw(struct ata_port *ap);
@@ -317,9 +317,9 @@ static inline void __iomem *sil_scr_addr(struct ata_port *ap,
 	return NULL;
 }
 
-static int sil_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int sil_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
-	void __iomem *mmio = sil_scr_addr(ap, sc_reg);
+	void __iomem *mmio = sil_scr_addr(link->ap, sc_reg);
 
 	if (mmio) {
 		*val = readl(mmio);
@@ -328,9 +328,9 @@ static int sil_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 	return -EINVAL;
 }
 
-static int sil_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int sil_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
-	void __iomem *mmio = sil_scr_addr(ap, sc_reg);
+	void __iomem *mmio = sil_scr_addr(link->ap, sc_reg);
 
 	if (mmio) {
 		writel(val, mmio);
@@ -352,8 +352,8 @@ static void sil_host_intr(struct ata_port *ap, u32 bmdma2)
 		 * controllers continue to assert IRQ as long as
 		 * SError bits are pending.  Clear SError immediately.
 		 */
-		sil_scr_read(ap, SCR_ERROR, &serror);
-		sil_scr_write(ap, SCR_ERROR, serror);
+		sil_scr_read(&ap->link, SCR_ERROR, &serror);
+		sil_scr_write(&ap->link, SCR_ERROR, serror);
 
 		/* Sometimes spurious interrupts occur, double check
 		 * it's PHYRDY CHG.

drivers/ata/sata_sil24.c

@@ -340,8 +340,8 @@ struct sil24_port_priv {
 };
 
 static void sil24_dev_config(struct ata_device *dev);
-static int sil24_scr_read(struct ata_port *ap, unsigned sc_reg, u32 *val);
-static int sil24_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val);
+static int sil24_scr_read(struct ata_link *link, unsigned sc_reg, u32 *val);
+static int sil24_scr_write(struct ata_link *link, unsigned sc_reg, u32 val);
 static int sil24_qc_defer(struct ata_queued_cmd *qc);
 static void sil24_qc_prep(struct ata_queued_cmd *qc);
 static unsigned int sil24_qc_issue(struct ata_queued_cmd *qc);
@@ -504,9 +504,9 @@ static int sil24_scr_map[] = {
 	[SCR_ACTIVE]	= 3,
 };
 
-static int sil24_scr_read(struct ata_port *ap, unsigned sc_reg, u32 *val)
+static int sil24_scr_read(struct ata_link *link, unsigned sc_reg, u32 *val)
 {
-	void __iomem *scr_addr = sil24_port_base(ap) + PORT_SCONTROL;
+	void __iomem *scr_addr = sil24_port_base(link->ap) + PORT_SCONTROL;
 
 	if (sc_reg < ARRAY_SIZE(sil24_scr_map)) {
 		void __iomem *addr;
@@ -517,9 +517,9 @@ static int sil24_scr_read(struct ata_port *ap, unsigned sc_reg, u32 *val)
 	return -EINVAL;
 }
 
-static int sil24_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val)
+static int sil24_scr_write(struct ata_link *link, unsigned sc_reg, u32 val)
 {
-	void __iomem *scr_addr = sil24_port_base(ap) + PORT_SCONTROL;
+	void __iomem *scr_addr = sil24_port_base(link->ap) + PORT_SCONTROL;
 
 	if (sc_reg < ARRAY_SIZE(sil24_scr_map)) {
 		void __iomem *addr;

drivers/ata/sata_sis.c

@@ -64,8 +64,8 @@ enum {
 };
 
 static int sis_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
-static int sis_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int sis_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int sis_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int sis_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 
 static const struct pci_device_id sis_pci_tbl[] = {
 	{ PCI_VDEVICE(SI, 0x0180), sis_180 },	/* SiS 964/180 */
@@ -134,10 +134,11 @@ static unsigned int get_scr_cfg_addr(struct ata_port *ap, unsigned int sc_reg)
 	return addr;
 }
 
-static u32 sis_scr_cfg_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static u32 sis_scr_cfg_read(struct ata_link *link,
+			    unsigned int sc_reg, u32 *val)
 {
-	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-	unsigned int cfg_addr = get_scr_cfg_addr(ap, sc_reg);
+	struct pci_dev *pdev = to_pci_dev(link->ap->host->dev);
+	unsigned int cfg_addr = get_scr_cfg_addr(link->ap, sc_reg);
 	u32 val2 = 0;
 	u8 pmr;
 
@@ -158,10 +159,11 @@ static u32 sis_scr_cfg_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 	return 0;
 }
 
-static int sis_scr_cfg_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int sis_scr_cfg_write(struct ata_link *link,
+			     unsigned int sc_reg, u32 val)
 {
-	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-	unsigned int cfg_addr = get_scr_cfg_addr(ap, sc_reg);
+	struct pci_dev *pdev = to_pci_dev(link->ap->host->dev);
+	unsigned int cfg_addr = get_scr_cfg_addr(link->ap, sc_reg);
 	u8 pmr;
 
 	if (sc_reg == SCR_ERROR) /* doesn't exist in PCI cfg space */
@@ -178,8 +180,9 @@ static int sis_scr_cfg_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
 	return 0;
 }
 
-static int sis_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int sis_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
+	struct ata_port *ap = link->ap;
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 	u8 pmr;
 
@@ -187,7 +190,7 @@ static int sis_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 		return -EINVAL;
 
 	if (ap->flags & SIS_FLAG_CFGSCR)
-		return sis_scr_cfg_read(ap, sc_reg, val);
+		return sis_scr_cfg_read(link, sc_reg, val);
 
 	pci_read_config_byte(pdev, SIS_PMR, &pmr);
 
@@ -202,8 +205,9 @@ static int sis_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 	return 0;
 }
 
-static int sis_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int sis_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
+	struct ata_port *ap = link->ap;
 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 	u8 pmr;
 
@@ -213,7 +217,7 @@ static int sis_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
 	pci_read_config_byte(pdev, SIS_PMR, &pmr);
 
 	if (ap->flags & SIS_FLAG_CFGSCR)
-		return sis_scr_cfg_write(ap, sc_reg, val);
+		return sis_scr_cfg_write(link, sc_reg, val);
 	else {
 		iowrite32(val, ap->ioaddr.scr_addr + (sc_reg * 4));
 		if ((pdev->device == 0x0182) || (pdev->device == 0x0183) ||

drivers/ata/sata_svw.c

@@ -123,20 +123,22 @@ static int k2_sata_check_atapi_dma(struct ata_queued_cmd *qc)
 	}
 }
 
-static int k2_sata_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int k2_sata_scr_read(struct ata_link *link,
+			    unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	*val = readl(ap->ioaddr.scr_addr + (sc_reg * 4));
+	*val = readl(link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 
 
-static int k2_sata_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int k2_sata_scr_write(struct ata_link *link,
+			     unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	writel(val, ap->ioaddr.scr_addr + (sc_reg * 4));
+	writel(val, link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 

drivers/ata/sata_uli.c

@@ -57,8 +57,8 @@ struct uli_priv {
 };
 
 static int uli_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
-static int uli_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int uli_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int uli_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int uli_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 
 static const struct pci_device_id uli_pci_tbl[] = {
 	{ PCI_VDEVICE(AL, 0x5289), uli_5289 },
@@ -107,39 +107,39 @@ static unsigned int get_scr_cfg_addr(struct ata_port *ap, unsigned int sc_reg)
 	return hpriv->scr_cfg_addr[ap->port_no] + (4 * sc_reg);
 }
 
-static u32 uli_scr_cfg_read(struct ata_port *ap, unsigned int sc_reg)
+static u32 uli_scr_cfg_read(struct ata_link *link, unsigned int sc_reg)
 {
-	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-	unsigned int cfg_addr = get_scr_cfg_addr(ap, sc_reg);
+	struct pci_dev *pdev = to_pci_dev(link->ap->host->dev);
+	unsigned int cfg_addr = get_scr_cfg_addr(link->ap, sc_reg);
 	u32 val;
 
 	pci_read_config_dword(pdev, cfg_addr, &val);
 	return val;
 }
 
-static void uli_scr_cfg_write(struct ata_port *ap, unsigned int scr, u32 val)
+static void uli_scr_cfg_write(struct ata_link *link, unsigned int scr, u32 val)
 {
-	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-	unsigned int cfg_addr = get_scr_cfg_addr(ap, scr);
+	struct pci_dev *pdev = to_pci_dev(link->ap->host->dev);
+	unsigned int cfg_addr = get_scr_cfg_addr(link->ap, scr);
 
 	pci_write_config_dword(pdev, cfg_addr, val);
 }
 
-static int uli_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int uli_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
 
-	*val = uli_scr_cfg_read(ap, sc_reg);
+	*val = uli_scr_cfg_read(link, sc_reg);
 	return 0;
 }
 
-static int uli_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int uli_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL) //SCR_CONTROL=2, SCR_ERROR=1, SCR_STATUS=0
 		return -EINVAL;
 
-	uli_scr_cfg_write(ap, sc_reg, val);
+	uli_scr_cfg_write(link, sc_reg, val);
 	return 0;
 }
 

drivers/ata/sata_via.c

@@ -68,8 +68,8 @@ enum {
 };
 
 static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
-static int svia_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
-static int svia_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static void svia_noop_freeze(struct ata_port *ap);
 static int vt6420_prereset(struct ata_link *link, unsigned long deadline);
 static int vt6421_pata_cable_detect(struct ata_port *ap);
@@ -152,19 +152,19 @@ MODULE_LICENSE("GPL");
 MODULE_DEVICE_TABLE(pci, svia_pci_tbl);
 MODULE_VERSION(DRV_VERSION);
 
-static int svia_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	*val = ioread32(ap->ioaddr.scr_addr + (4 * sc_reg));
+	*val = ioread32(link->ap->ioaddr.scr_addr + (4 * sc_reg));
 	return 0;
 }
 
-static int svia_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	iowrite32(val, ap->ioaddr.scr_addr + (4 * sc_reg));
+	iowrite32(val, link->ap->ioaddr.scr_addr + (4 * sc_reg));
 	return 0;
 }
 
@@ -210,20 +210,20 @@ static int vt6420_prereset(struct ata_link *link, unsigned long deadline)
 		goto skip_scr;
 
 	/* Resume phy.  This is the old SATA resume sequence */
-	svia_scr_write(ap, SCR_CONTROL, 0x300);
-	svia_scr_read(ap, SCR_CONTROL, &scontrol); /* flush */
+	svia_scr_write(link, SCR_CONTROL, 0x300);
+	svia_scr_read(link, SCR_CONTROL, &scontrol); /* flush */
 
 	/* wait for phy to become ready, if necessary */
 	do {
 		msleep(200);
-		svia_scr_read(ap, SCR_STATUS, &sstatus);
+		svia_scr_read(link, SCR_STATUS, &sstatus);
 		if ((sstatus & 0xf) != 1)
 			break;
 	} while (time_before(jiffies, timeout));
 
 	/* open code sata_print_link_status() */
-	svia_scr_read(ap, SCR_STATUS, &sstatus);
-	svia_scr_read(ap, SCR_CONTROL, &scontrol);
+	svia_scr_read(link, SCR_STATUS, &sstatus);
+	svia_scr_read(link, SCR_CONTROL, &scontrol);
 
 	online = (sstatus & 0xf) == 0x3;
 
@@ -232,7 +232,7 @@ static int vt6420_prereset(struct ata_link *link, unsigned long deadline)
 			online ? "up" : "down", sstatus, scontrol);
 
 	/* SStatus is read one more time */
-	svia_scr_read(ap, SCR_STATUS, &sstatus);
+	svia_scr_read(link, SCR_STATUS, &sstatus);
 
 	if (!online) {
 		/* tell EH to bail */

drivers/ata/sata_vsc.c

@@ -98,20 +98,22 @@ enum {
 			      VSC_SATA_INT_PHY_CHANGE),
 };
 
-static int vsc_sata_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
+static int vsc_sata_scr_read(struct ata_link *link,
+			     unsigned int sc_reg, u32 *val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	*val = readl(ap->ioaddr.scr_addr + (sc_reg * 4));
+	*val = readl(link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 
 
-static int vsc_sata_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int vsc_sata_scr_write(struct ata_link *link,
+			      unsigned int sc_reg, u32 val)
 {
 	if (sc_reg > SCR_CONTROL)
 		return -EINVAL;
-	writel(val, ap->ioaddr.scr_addr + (sc_reg * 4));
+	writel(val, link->ap->ioaddr.scr_addr + (sc_reg * 4));
 	return 0;
 }
 

drivers/scsi/libsas/sas_ata.c

@@ -294,10 +294,10 @@ static void sas_ata_post_internal(struct ata_queued_cmd *qc)
 	}
 }
 
-static int sas_ata_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
+static int sas_ata_scr_write(struct ata_link *link, unsigned int sc_reg_in,
 			      u32 val)
 {
-	struct domain_device *dev = ap->private_data;
+	struct domain_device *dev = link->ap->private_data;
 
 	SAS_DPRINTK("STUB %s\n", __func__);
 	switch (sc_reg_in) {
@@ -319,10 +319,10 @@ static int sas_ata_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
 	return 0;
 }
 
-static int sas_ata_scr_read(struct ata_port *ap, unsigned int sc_reg_in,
+static int sas_ata_scr_read(struct ata_link *link, unsigned int sc_reg_in,
 			    u32 *val)
 {
-	struct domain_device *dev = ap->private_data;
+	struct domain_device *dev = link->ap->private_data;
 
 	SAS_DPRINTK("STUB %s\n", __func__);
 	switch (sc_reg_in) {

include/linux/ata.h

@@ -667,6 +667,15 @@ static inline int ata_id_has_dword_io(const u16 *id)
 	return 0;
 }
 
+static inline int ata_id_has_unload(const u16 *id)
+{
+	if (ata_id_major_version(id) >= 7 &&
+	    (id[ATA_ID_CFSSE] & 0xC000) == 0x4000 &&
+	    id[ATA_ID_CFSSE] & (1 << 13))
+		return 1;
+	return 0;
+}
+
 static inline int ata_id_current_chs_valid(const u16 *id)
 {
 	/* For ATA-1 devices, if the INITIALIZE DEVICE PARAMETERS command

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 +321,11 @@ 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,
 
 	/* ata_eh_info->flags */
 	ATA_EHI_HOTPLUGGED	= (1 << 0),  /* could have been hotplugged */
@@ -452,6 +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;
@@ -554,8 +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;
@@ -564,6 +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;
@@ -621,6 +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 */
@@ -688,7 +696,8 @@ 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 */
@@ -709,6 +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;
@@ -772,8 +782,8 @@ 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);
@@ -895,6 +905,7 @@ 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);
@@ -920,8 +931,8 @@ 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);
@@ -1098,6 +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,			\
@@ -1112,7 +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),					\
@@ -1134,7 +1147,7 @@ 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)
@@ -1167,7 +1180,7 @@ 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 \
@@ -1265,34 +1278,17 @@ 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; \