Initial import

1 files changed, 1106 insertions, 0 deletions

diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
new file mode 100644
index 000000000..b9f7ce8de
--- /dev/null
+++ b/drivers/ata/libata-pmp.c
@@ -0,0 +1,1106 @@
+/*
+ * libata-pmp.c - libata port multiplier support
+ *
+ * Copyright (c) 2007  SUSE Linux Products GmbH
+ * Copyright (c) 2007  Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/libata.h>
+#include <linux/slab.h>
+#include "libata.h"
+#include "libata-transport.h"
+
+const struct ata_port_operations sata_pmp_port_ops = {
+	.inherits		= &sata_port_ops,
+	.pmp_prereset		= ata_std_prereset,
+	.pmp_hardreset		= sata_std_hardreset,
+	.pmp_postreset		= ata_std_postreset,
+	.error_handler		= sata_pmp_error_handler,
+};
+
+/**
+ *	sata_pmp_read - read PMP register
+ *	@link: link to read PMP register for
+ *	@reg: register to read
+ *	@r_val: resulting value
+ *
+ *	Read PMP register.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, AC_ERR_* mask on failure.
+ */
+static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_device *pmp_dev = ap->link.device;
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+
+	ata_tf_init(pmp_dev, &tf);
+	tf.command = ATA_CMD_PMP_READ;
+	tf.protocol = ATA_PROT_NODATA;
+	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
+	tf.feature = reg;
+	tf.device = link->pmp;
+
+	err_mask = ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
+				     SATA_PMP_RW_TIMEOUT);
+	if (err_mask)
+		return err_mask;
+
+	*r_val = tf.nsect | tf.lbal << 8 | tf.lbam << 16 | tf.lbah << 24;
+	return 0;
+}
+
+/**
+ *	sata_pmp_write - write PMP register
+ *	@link: link to write PMP register for
+ *	@reg: register to write
+ *	@r_val: value to write
+ *
+ *	Write PMP register.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, AC_ERR_* mask on failure.
+ */
+static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_device *pmp_dev = ap->link.device;
+	struct ata_taskfile tf;
+
+	ata_tf_init(pmp_dev, &tf);
+	tf.command = ATA_CMD_PMP_WRITE;
+	tf.protocol = ATA_PROT_NODATA;
+	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
+	tf.feature = reg;
+	tf.device = link->pmp;
+	tf.nsect = val & 0xff;
+	tf.lbal = (val >> 8) & 0xff;
+	tf.lbam = (val >> 16) & 0xff;
+	tf.lbah = (val >> 24) & 0xff;
+
+	return ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
+				 SATA_PMP_RW_TIMEOUT);
+}
+
+/**
+ *	sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
+ *	@qc: ATA command in question
+ *
+ *	A host which has command switching PMP support cannot issue
+ *	commands to multiple links simultaneously.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ *
+ *	RETURNS:
+ *	ATA_DEFER_* if deferring is needed, 0 otherwise.
+ */
+int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
+{
+	struct ata_link *link = qc->dev->link;
+	struct ata_port *ap = link->ap;
+
+	if (ap->excl_link == NULL || ap->excl_link == link) {
+		if (ap->nr_active_links == 0 || ata_link_active(link)) {
+			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
+			return ata_std_qc_defer(qc);
+		}
+
+		ap->excl_link = link;
+	}
+
+	return ATA_DEFER_PORT;
+}
+
+/**
+ *	sata_pmp_scr_read - read PSCR
+ *	@link: ATA link to read PSCR for
+ *	@reg: PSCR to read
+ *	@r_val: resulting value
+ *
+ *	Read PSCR @reg into @r_val for @link, to be called from
+ *	ata_scr_read().
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
+{
+	unsigned int err_mask;
+
+	if (reg > SATA_PMP_PSCR_CONTROL)
+		return -EINVAL;
+
+	err_mask = sata_pmp_read(link, reg, r_val);
+	if (err_mask) {
+		ata_link_warn(link, "failed to read SCR %d (Emask=0x%x)\n",
+			      reg, err_mask);
+		return -EIO;
+	}
+	return 0;
+}
+
+/**
+ *	sata_pmp_scr_write - write PSCR
+ *	@link: ATA link to write PSCR for
+ *	@reg: PSCR to write
+ *	@val: value to be written
+ *
+ *	Write @val to PSCR @reg for @link, to be called from
+ *	ata_scr_write() and ata_scr_write_flush().
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
+{
+	unsigned int err_mask;
+
+	if (reg > SATA_PMP_PSCR_CONTROL)
+		return -EINVAL;
+
+	err_mask = sata_pmp_write(link, reg, val);
+	if (err_mask) {
+		ata_link_warn(link, "failed to write SCR %d (Emask=0x%x)\n",
+			      reg, err_mask);
+		return -EIO;
+	}
+	return 0;
+}
+
+/**
+ *	sata_pmp_set_lpm - configure LPM for a PMP link
+ *	@link: PMP link to configure LPM for
+ *	@policy: target LPM policy
+ *	@hints: LPM hints
+ *
+ *	Configure LPM for @link.  This function will contain any PMP
+ *	specific workarounds if necessary.
+ *
+ *	LOCKING:
+ *	EH context.
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_pmp_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
+		     unsigned hints)
+{
+	return sata_link_scr_lpm(link, policy, true);
+}
+
+/**
+ *	sata_pmp_read_gscr - read GSCR block of SATA PMP
+ *	@dev: PMP device
+ *	@gscr: buffer to read GSCR block into
+ *
+ *	Read selected PMP GSCRs from the PMP at @dev.  This will serve
+ *	as configuration and identification info for the PMP.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
+{
+	static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
+		int reg = gscr_to_read[i];
+		unsigned int err_mask;
+
+		err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
+		if (err_mask) {
+			ata_dev_err(dev, "failed to read PMP GSCR[%d] (Emask=0x%x)\n",
+				    reg, err_mask);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static const char *sata_pmp_spec_rev_str(const u32 *gscr)
+{
+	u32 rev = gscr[SATA_PMP_GSCR_REV];
+
+	if (rev & (1 << 3))
+		return "1.2";
+	if (rev & (1 << 2))
+		return "1.1";
+	if (rev & (1 << 1))
+		return "1.0";
+	return "<unknown>";
+}
+
+#define PMP_GSCR_SII_POL 129
+
+static int sata_pmp_configure(struct ata_device *dev, int print_info)
+{
+	struct ata_port *ap = dev->link->ap;
+	u32 *gscr = dev->gscr;
+	u16 vendor = sata_pmp_gscr_vendor(gscr);
+	u16 devid = sata_pmp_gscr_devid(gscr);
+	unsigned int err_mask = 0;
+	const char *reason;
+	int nr_ports, rc;
+
+	nr_ports = sata_pmp_gscr_ports(gscr);
+
+	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
+		rc = -EINVAL;
+		reason = "invalid nr_ports";
+		goto fail;
+	}
+
+	if ((ap->flags & ATA_FLAG_AN) &&
+	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
+		dev->flags |= ATA_DFLAG_AN;
+
+	/* monitor SERR_PHYRDY_CHG on fan-out ports */
+	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
+				  SERR_PHYRDY_CHG);
+	if (err_mask) {
+		rc = -EIO;
+		reason = "failed to write GSCR_ERROR_EN";
+		goto fail;
+	}
+
+	/* Disable sending Early R_OK.
+	 * With "cached read" HDD testing and multiple ports busy on a SATA
+	 * host controller, 3x26 PMP will very rarely drop a deferred
+	 * R_OK that was intended for the host. Symptom will be all
+	 * 5 drives under test will timeout, get reset, and recover.
+	 */
+	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
+		u32 reg;
+
+		err_mask = sata_pmp_read(&ap->link, PMP_GSCR_SII_POL, &reg);
+		if (err_mask) {
+			rc = -EIO;
+			reason = "failed to read Sil3x26 Private Register";
+			goto fail;
+		}
+		reg &= ~0x1;
+		err_mask = sata_pmp_write(&ap->link, PMP_GSCR_SII_POL, reg);
+		if (err_mask) {
+			rc = -EIO;
+			reason = "failed to write Sil3x26 Private Register";
+			goto fail;
+		}
+	}
+
+	if (print_info) {
+		ata_dev_info(dev, "Port Multiplier %s, "
+			     "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
+			     sata_pmp_spec_rev_str(gscr), vendor, devid,
+			     sata_pmp_gscr_rev(gscr),
+			     nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
+			     gscr[SATA_PMP_GSCR_FEAT]);
+
+		if (!(dev->flags & ATA_DFLAG_AN))
+			ata_dev_info(dev,
+				"Asynchronous notification not supported, "
+				"hotplug won't work on fan-out ports. Use warm-plug instead.\n");
+	}
+
+	return 0;
+
+ fail:
+	ata_dev_err(dev,
+		    "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
+		    reason, err_mask);
+	return rc;
+}
+
+static int sata_pmp_init_links (struct ata_port *ap, int nr_ports)
+{
+	struct ata_link *pmp_link = ap->pmp_link;
+	int i, err;
+
+	if (!pmp_link) {
+		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
+				   GFP_NOIO);
+		if (!pmp_link)
+			return -ENOMEM;
+
+		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
+			ata_link_init(ap, &pmp_link[i], i);
+
+		ap->pmp_link = pmp_link;
+
+		for (i = 0; i < SATA_PMP_MAX_PORTS; i++) {
+			err = ata_tlink_add(&pmp_link[i]);
+			if (err) {
+				goto err_tlink;
+			}
+		}
+	}
+
+	for (i = 0; i < nr_ports; i++) {
+		struct ata_link *link = &pmp_link[i];
+		struct ata_eh_context *ehc = &link->eh_context;
+
+		link->flags = 0;
+		ehc->i.probe_mask |= ATA_ALL_DEVICES;
+		ehc->i.action |= ATA_EH_RESET;
+	}
+
+	return 0;
+  err_tlink:
+	while (--i >= 0)
+		ata_tlink_delete(&pmp_link[i]);
+	kfree(pmp_link);
+	ap->pmp_link = NULL;
+	return err;
+}
+
+static void sata_pmp_quirks(struct ata_port *ap)
+{
+	u32 *gscr = ap->link.device->gscr;
+	u16 vendor = sata_pmp_gscr_vendor(gscr);
+	u16 devid = sata_pmp_gscr_devid(gscr);
+	struct ata_link *link;
+
+	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
+		/* sil3x26 quirks */
+		ata_for_each_link(link, ap, EDGE) {
+			/* link reports offline after LPM */
+			link->flags |= ATA_LFLAG_NO_LPM;
+
+			/*
+			 * Class code report is unreliable and SRST times
+			 * out under certain configurations.
+			 */
+			if (link->pmp < 5)
+				link->flags |= ATA_LFLAG_NO_SRST |
+					       ATA_LFLAG_ASSUME_ATA;
+
+			/* port 5 is for SEMB device and it doesn't like SRST */
+			if (link->pmp == 5)
+				link->flags |= ATA_LFLAG_NO_SRST |
+					       ATA_LFLAG_ASSUME_SEMB;
+		}
+	} else if (vendor == 0x1095 && devid == 0x4723) {
+		/*
+		 * sil4723 quirks
+		 *
+		 * Link reports offline after LPM.  Class code report is
+		 * unreliable.  SIMG PMPs never got SRST reliable and the
+		 * config device at port 2 locks up on SRST.
+		 */
+		ata_for_each_link(link, ap, EDGE)
+			link->flags |= ATA_LFLAG_NO_LPM |
+				       ATA_LFLAG_NO_SRST |
+				       ATA_LFLAG_ASSUME_ATA;
+	} else if (vendor == 0x1095 && devid == 0x4726) {
+		/* sil4726 quirks */
+		ata_for_each_link(link, ap, EDGE) {
+			/* link reports offline after LPM */
+			link->flags |= ATA_LFLAG_NO_LPM;
+
+			/* Class code report is unreliable and SRST
+			 * times out under certain configurations.
+			 * Config device can be at port 0 or 5 and
+			 * locks up on SRST.
+			 */
+			if (link->pmp <= 5)
+				link->flags |= ATA_LFLAG_NO_SRST |
+					       ATA_LFLAG_ASSUME_ATA;
+
+			/* Port 6 is for SEMB device which doesn't
+			 * like SRST either.
+			 */
+			if (link->pmp == 6)
+				link->flags |= ATA_LFLAG_NO_SRST |
+					       ATA_LFLAG_ASSUME_SEMB;
+		}
+	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
+					devid == 0x5734 || devid == 0x5744)) {
+		/* sil5723/5744 quirks */
+
+		/* sil5723/5744 has either two or three downstream
+		 * ports depending on operation mode.  The last port
+		 * is empty if any actual IO device is available or
+		 * occupied by a pseudo configuration device
+		 * otherwise.  Don't try hard to recover it.
+		 */
+		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
+	} else if (vendor == 0x197b && (devid == 0x2352 || devid == 0x0325)) {
+		/*
+		 * 0x2352: found in Thermaltake BlackX Duet, jmicron JMB350?
+		 * 0x0325: jmicron JMB394.
+		 */
+		ata_for_each_link(link, ap, EDGE) {
+			/* SRST breaks detection and disks get misclassified
+			 * LPM disabled to avoid potential problems
+			 */
+			link->flags |= ATA_LFLAG_NO_LPM |
+				       ATA_LFLAG_NO_SRST |
+				       ATA_LFLAG_ASSUME_ATA;
+		}
+	}
+}
+
+/**
+ *	sata_pmp_attach - attach a SATA PMP device
+ *	@dev: SATA PMP device to attach
+ *
+ *	Configure and attach SATA PMP device @dev.  This function is
+ *	also responsible for allocating and initializing PMP links.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_pmp_attach(struct ata_device *dev)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	unsigned long flags;
+	struct ata_link *tlink;
+	int rc;
+
+	/* is it hanging off the right place? */
+	if (!sata_pmp_supported(ap)) {
+		ata_dev_err(dev, "host does not support Port Multiplier\n");
+		return -EINVAL;
+	}
+
+	if (!ata_is_host_link(link)) {
+		ata_dev_err(dev, "Port Multipliers cannot be nested\n");
+		return -EINVAL;
+	}
+
+	if (dev->devno) {
+		ata_dev_err(dev, "Port Multiplier must be the first device\n");
+		return -EINVAL;
+	}
+
+	WARN_ON(link->pmp != 0);
+	link->pmp = SATA_PMP_CTRL_PORT;
+
+	/* read GSCR block */
+	rc = sata_pmp_read_gscr(dev, dev->gscr);
+	if (rc)
+		goto fail;
+
+	/* config PMP */
+	rc = sata_pmp_configure(dev, 1);
+	if (rc)
+		goto fail;
+
+	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
+	if (rc) {
+		ata_dev_info(dev, "failed to initialize PMP links\n");
+		goto fail;
+	}
+
+	/* attach it */
+	spin_lock_irqsave(ap->lock, flags);
+	WARN_ON(ap->nr_pmp_links);
+	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	sata_pmp_quirks(ap);
+
+	if (ap->ops->pmp_attach)
+		ap->ops->pmp_attach(ap);
+
+	ata_for_each_link(tlink, ap, EDGE)
+		sata_link_init_config(tlink);
+
+	return 0;
+
+ fail:
+	link->pmp = 0;
+	return rc;
+}
+
+/**
+ *	sata_pmp_detach - detach a SATA PMP device
+ *	@dev: SATA PMP device to detach
+ *
+ *	Detach SATA PMP device @dev.  This function is also
+ *	responsible for deconfiguring PMP links.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ */
+static void sata_pmp_detach(struct ata_device *dev)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	struct ata_link *tlink;
+	unsigned long flags;
+
+	ata_dev_info(dev, "Port Multiplier detaching\n");
+
+	WARN_ON(!ata_is_host_link(link) || dev->devno ||
+		link->pmp != SATA_PMP_CTRL_PORT);
+
+	if (ap->ops->pmp_detach)
+		ap->ops->pmp_detach(ap);
+
+	ata_for_each_link(tlink, ap, EDGE)
+		ata_eh_detach_dev(tlink->device);
+
+	spin_lock_irqsave(ap->lock, flags);
+	ap->nr_pmp_links = 0;
+	link->pmp = 0;
+	spin_unlock_irqrestore(ap->lock, flags);
+}
+
+/**
+ *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
+ *	@dev: PMP device to compare against
+ *	@new_gscr: GSCR block of the new device
+ *
+ *	Compare @new_gscr against @dev and determine whether @dev is
+ *	the PMP described by @new_gscr.
+ *
+ *	LOCKING:
+ *	None.
+ *
+ *	RETURNS:
+ *	1 if @dev matches @new_gscr, 0 otherwise.
+ */
+static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
+{
+	const u32 *old_gscr = dev->gscr;
+	u16 old_vendor, new_vendor, old_devid, new_devid;
+	int old_nr_ports, new_nr_ports;
+
+	old_vendor = sata_pmp_gscr_vendor(old_gscr);
+	new_vendor = sata_pmp_gscr_vendor(new_gscr);
+	old_devid = sata_pmp_gscr_devid(old_gscr);
+	new_devid = sata_pmp_gscr_devid(new_gscr);
+	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
+	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
+
+	if (old_vendor != new_vendor) {
+		ata_dev_info(dev,
+			     "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
+			     old_vendor, new_vendor);
+		return 0;
+	}
+
+	if (old_devid != new_devid) {
+		ata_dev_info(dev,
+			     "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
+			     old_devid, new_devid);
+		return 0;
+	}
+
+	if (old_nr_ports != new_nr_ports) {
+		ata_dev_info(dev,
+			     "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
+			     old_nr_ports, new_nr_ports);
+		return 0;
+	}
+
+	return 1;
+}
+
+/**
+ *	sata_pmp_revalidate - revalidate SATA PMP
+ *	@dev: PMP device to revalidate
+ *	@new_class: new class code
+ *
+ *	Re-read GSCR block and make sure @dev is still attached to the
+ *	port and properly configured.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	u32 *gscr = (void *)ap->sector_buf;
+	int rc;
+
+	DPRINTK("ENTER\n");
+
+	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
+
+	if (!ata_dev_enabled(dev)) {
+		rc = -ENODEV;
+		goto fail;
+	}
+
+	/* wrong class? */
+	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
+		rc = -ENODEV;
+		goto fail;
+	}
+
+	/* read GSCR */
+	rc = sata_pmp_read_gscr(dev, gscr);
+	if (rc)
+		goto fail;
+
+	/* is the pmp still there? */
+	if (!sata_pmp_same_pmp(dev, gscr)) {
+		rc = -ENODEV;
+		goto fail;
+	}
+
+	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
+
+	rc = sata_pmp_configure(dev, 0);
+	if (rc)
+		goto fail;
+
+	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
+
+	DPRINTK("EXIT, rc=0\n");
+	return 0;
+
+ fail:
+	ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
+	DPRINTK("EXIT, rc=%d\n", rc);
+	return rc;
+}
+
+/**
+ *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
+ *	@dev: PMP device to revalidate
+ *
+ *	Make sure the attached PMP is accessible.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+static int sata_pmp_revalidate_quick(struct ata_device *dev)
+{
+	unsigned int err_mask;
+	u32 prod_id;
+
+	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
+	if (err_mask) {
+		ata_dev_err(dev,
+			    "failed to read PMP product ID (Emask=0x%x)\n",
+			    err_mask);
+		return -EIO;
+	}
+
+	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
+		ata_dev_err(dev, "PMP product ID mismatch\n");
+		/* something weird is going on, request full PMP recovery */
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ *	sata_pmp_eh_recover_pmp - recover PMP
+ *	@ap: ATA port PMP is attached to
+ *	@prereset: prereset method (can be NULL)
+ *	@softreset: softreset method
+ *	@hardreset: hardreset method
+ *	@postreset: postreset method (can be NULL)
+ *
+ *	Recover PMP attached to @ap.  Recovery procedure is somewhat
+ *	similar to that of ata_eh_recover() except that reset should
+ *	always be performed in hard->soft sequence and recovery
+ *	failure results in PMP detachment.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
+		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
+		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+{
+	struct ata_link *link = &ap->link;
+	struct ata_eh_context *ehc = &link->eh_context;
+	struct ata_device *dev = link->device;
+	int tries = ATA_EH_PMP_TRIES;
+	int detach = 0, rc = 0;
+	int reval_failed = 0;
+
+	DPRINTK("ENTER\n");
+
+	if (dev->flags & ATA_DFLAG_DETACH) {
+		detach = 1;
+		goto fail;
+	}
+
+ retry:
+	ehc->classes[0] = ATA_DEV_UNKNOWN;
+
+	if (ehc->i.action & ATA_EH_RESET) {
+		struct ata_link *tlink;
+
+		/* reset */
+		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
+				  postreset);
+		if (rc) {
+			ata_link_err(link, "failed to reset PMP, giving up\n");
+			goto fail;
+		}
+
+		/* PMP is reset, SErrors cannot be trusted, scan all */
+		ata_for_each_link(tlink, ap, EDGE) {
+			struct ata_eh_context *ehc = &tlink->eh_context;
+
+			ehc->i.probe_mask |= ATA_ALL_DEVICES;
+			ehc->i.action |= ATA_EH_RESET;
+		}
+	}
+
+	/* If revalidation is requested, revalidate and reconfigure;
+	 * otherwise, do quick revalidation.
+	 */
+	if (ehc->i.action & ATA_EH_REVALIDATE)
+		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
+	else
+		rc = sata_pmp_revalidate_quick(dev);
+
+	if (rc) {
+		tries--;
+
+		if (rc == -ENODEV) {
+			ehc->i.probe_mask |= ATA_ALL_DEVICES;
+			detach = 1;
+			/* give it just two more chances */
+			tries = min(tries, 2);
+		}
+
+		if (tries) {
+			/* consecutive revalidation failures? speed down */
+			if (reval_failed)
+				sata_down_spd_limit(link, 0);
+			else
+				reval_failed = 1;
+
+			ehc->i.action |= ATA_EH_RESET;
+			goto retry;
+		} else {
+			ata_dev_err(dev,
+				    "failed to recover PMP after %d tries, giving up\n",
+				    ATA_EH_PMP_TRIES);
+			goto fail;
+		}
+	}
+
+	/* okay, PMP resurrected */
+	ehc->i.flags = 0;
+
+	DPRINTK("EXIT, rc=0\n");
+	return 0;
+
+ fail:
+	sata_pmp_detach(dev);
+	if (detach)
+		ata_eh_detach_dev(dev);
+	else
+		ata_dev_disable(dev);
+
+	DPRINTK("EXIT, rc=%d\n", rc);
+	return rc;
+}
+
+static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
+{
+	struct ata_link *link;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	ata_for_each_link(link, ap, EDGE) {
+		if (!(link->flags & ATA_LFLAG_DISABLED))
+			continue;
+
+		spin_unlock_irqrestore(ap->lock, flags);
+
+		/* Some PMPs require hardreset sequence to get
+		 * SError.N working.
+		 */
+		sata_link_hardreset(link, sata_deb_timing_normal,
+				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
+				NULL, NULL);
+
+		/* unconditionally clear SError.N */
+		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
+		if (rc) {
+			ata_link_err(link,
+				     "failed to clear SError.N (errno=%d)\n",
+				     rc);
+			return rc;
+		}
+
+		spin_lock_irqsave(ap->lock, flags);
+	}
+
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	return 0;
+}
+
+static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
+{
+	struct ata_port *ap = link->ap;
+	unsigned long flags;
+
+	if (link_tries[link->pmp] && --link_tries[link->pmp])
+		return 1;
+
+	/* disable this link */
+	if (!(link->flags & ATA_LFLAG_DISABLED)) {
+		ata_link_warn(link,
+			"failed to recover link after %d tries, disabling\n",
+			ATA_EH_PMP_LINK_TRIES);
+
+		spin_lock_irqsave(ap->lock, flags);
+		link->flags |= ATA_LFLAG_DISABLED;
+		spin_unlock_irqrestore(ap->lock, flags);
+	}
+
+	ata_dev_disable(link->device);
+	link->eh_context.i.action = 0;
+
+	return 0;
+}
+
+/**
+ *	sata_pmp_eh_recover - recover PMP-enabled port
+ *	@ap: ATA port to recover
+ *
+ *	Drive EH recovery operation for PMP enabled port @ap.  This
+ *	function recovers host and PMP ports with proper retrials and
+ *	fallbacks.  Actual recovery operations are performed using
+ *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+static int sata_pmp_eh_recover(struct ata_port *ap)
+{
+	struct ata_port_operations *ops = ap->ops;
+	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
+	struct ata_link *pmp_link = &ap->link;
+	struct ata_device *pmp_dev = pmp_link->device;
+	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
+	u32 *gscr = pmp_dev->gscr;
+	struct ata_link *link;
+	struct ata_device *dev;
+	unsigned int err_mask;
+	u32 gscr_error, sntf;
+	int cnt, rc;
+
+	pmp_tries = ATA_EH_PMP_TRIES;
+	ata_for_each_link(link, ap, EDGE)
+		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
+
+ retry:
+	/* PMP attached? */
+	if (!sata_pmp_attached(ap)) {
+		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
+				    ops->hardreset, ops->postreset, NULL);
+		if (rc) {
+			ata_for_each_dev(dev, &ap->link, ALL)
+				ata_dev_disable(dev);
+			return rc;
+		}
+
+		if (pmp_dev->class != ATA_DEV_PMP)
+			return 0;
+
+		/* new PMP online */
+		ata_for_each_link(link, ap, EDGE)
+			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
+
+		/* fall through */
+	}
+
+	/* recover pmp */
+	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
+				     ops->hardreset, ops->postreset);
+	if (rc)
+		goto pmp_fail;
+
+	/* PHY event notification can disturb reset and other recovery
+	 * operations.  Turn it off.
+	 */
+	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
+		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
+
+		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
+					  gscr[SATA_PMP_GSCR_FEAT_EN]);
+		if (err_mask) {
+			ata_link_warn(pmp_link,
+				"failed to disable NOTIFY (err_mask=0x%x)\n",
+				err_mask);
+			goto pmp_fail;
+		}
+	}
+
+	/* handle disabled links */
+	rc = sata_pmp_eh_handle_disabled_links(ap);
+	if (rc)
+		goto pmp_fail;
+
+	/* recover links */
+	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
+			    ops->pmp_hardreset, ops->pmp_postreset, &link);
+	if (rc)
+		goto link_fail;
+
+	/* clear SNotification */
+	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
+	if (rc == 0)
+		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
+
+	/*
+	 * If LPM is active on any fan-out port, hotplug wouldn't
+	 * work.  Return w/ PHY event notification disabled.
+	 */
+	ata_for_each_link(link, ap, EDGE)
+		if (link->lpm_policy > ATA_LPM_MAX_POWER)
+			return 0;
+
+	/*
+	 * Connection status might have changed while resetting other
+	 * links, enable notification and check SATA_PMP_GSCR_ERROR
+	 * before returning.
+	 */
+
+	/* enable notification */
+	if (pmp_dev->flags & ATA_DFLAG_AN) {
+		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
+
+		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
+					  gscr[SATA_PMP_GSCR_FEAT_EN]);
+		if (err_mask) {
+			ata_dev_err(pmp_dev,
+				    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
+				    err_mask);
+			rc = -EIO;
+			goto pmp_fail;
+		}
+	}
+
+	/* check GSCR_ERROR */
+	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
+	if (err_mask) {
+		ata_dev_err(pmp_dev,
+			    "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
+			    err_mask);
+		rc = -EIO;
+		goto pmp_fail;
+	}
+
+	cnt = 0;
+	ata_for_each_link(link, ap, EDGE) {
+		if (!(gscr_error & (1 << link->pmp)))
+			continue;
+
+		if (sata_pmp_handle_link_fail(link, link_tries)) {
+			ata_ehi_hotplugged(&link->eh_context.i);
+			cnt++;
+		} else {
+			ata_link_warn(link,
+				"PHY status changed but maxed out on retries, giving up\n");
+			ata_link_warn(link,
+				"Manually issue scan to resume this link\n");
+		}
+	}
+
+	if (cnt) {
+		ata_port_info(ap,
+			"PMP SError.N set for some ports, repeating recovery\n");
+		goto retry;
+	}
+
+	return 0;
+
+ link_fail:
+	if (sata_pmp_handle_link_fail(link, link_tries)) {
+		pmp_ehc->i.action |= ATA_EH_RESET;
+		goto retry;
+	}
+
+	/* fall through */
+ pmp_fail:
+	/* Control always ends up here after detaching PMP.  Shut up
+	 * and return if we're unloading.
+	 */
+	if (ap->pflags & ATA_PFLAG_UNLOADING)
+		return rc;
+
+	if (!sata_pmp_attached(ap))
+		goto retry;
+
+	if (--pmp_tries) {
+		pmp_ehc->i.action |= ATA_EH_RESET;
+		goto retry;
+	}
+
+	ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
+		     ATA_EH_PMP_TRIES);
+	sata_pmp_detach(pmp_dev);
+	ata_dev_disable(pmp_dev);
+
+	return rc;
+}
+
+/**
+ *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
+ *	@ap: host port to handle error for
+ *
+ *	Perform standard error handling sequence for PMP-enabled host
+ *	@ap.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ */
+void sata_pmp_error_handler(struct ata_port *ap)
+{
+	ata_eh_autopsy(ap);
+	ata_eh_report(ap);
+	sata_pmp_eh_recover(ap);
+	ata_eh_finish(ap);
+}
+
+EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
+EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
+EXPORT_SYMBOL_GPL(sata_pmp_error_handler);