Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1492 insertions, 0 deletions

diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
new file mode 100644
index 000000000..71a00842e
--- /dev/null
+++ b/drivers/ata/libata-sata.c
@@ -0,0 +1,1492 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  SATA specific part of ATA helper library
+ *
+ *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
+ *  Copyright 2003-2004 Jeff Garzik
+ *  Copyright 2006 Tejun Heo <htejun@gmail.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <linux/libata.h>
+
+#include "libata.h"
+#include "libata-transport.h"
+
+/* debounce timing parameters in msecs { interval, duration, timeout } */
+const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
+EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
+const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
+EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
+const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
+EXPORT_SYMBOL_GPL(sata_deb_timing_long);
+
+/**
+ *	sata_scr_valid - test whether SCRs are accessible
+ *	@link: ATA link to test SCR accessibility for
+ *
+ *	Test whether SCRs are accessible for @link.
+ *
+ *	LOCKING:
+ *	None.
+ *
+ *	RETURNS:
+ *	1 if SCRs are accessible, 0 otherwise.
+ */
+int sata_scr_valid(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+
+	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
+}
+EXPORT_SYMBOL_GPL(sata_scr_valid);
+
+/**
+ *	sata_scr_read - read SCR register of the specified port
+ *	@link: ATA link to read SCR for
+ *	@reg: SCR to read
+ *	@val: Place to store read value
+ *
+ *	Read SCR register @reg of @link into *@val.  This function is
+ *	guaranteed to succeed if @link is ap->link, the cable type of
+ *	the port is SATA and the port implements ->scr_read.
+ *
+ *	LOCKING:
+ *	None if @link is ap->link.  Kernel thread context otherwise.
+ *
+ *	RETURNS:
+ *	0 on success, negative errno on failure.
+ */
+int sata_scr_read(struct ata_link *link, int reg, u32 *val)
+{
+	if (ata_is_host_link(link)) {
+		if (sata_scr_valid(link))
+			return link->ap->ops->scr_read(link, reg, val);
+		return -EOPNOTSUPP;
+	}
+
+	return sata_pmp_scr_read(link, reg, val);
+}
+EXPORT_SYMBOL_GPL(sata_scr_read);
+
+/**
+ *	sata_scr_write - write SCR register of the specified port
+ *	@link: ATA link to write SCR for
+ *	@reg: SCR to write
+ *	@val: value to write
+ *
+ *	Write @val to SCR register @reg of @link.  This function is
+ *	guaranteed to succeed if @link is ap->link, the cable type of
+ *	the port is SATA and the port implements ->scr_read.
+ *
+ *	LOCKING:
+ *	None if @link is ap->link.  Kernel thread context otherwise.
+ *
+ *	RETURNS:
+ *	0 on success, negative errno on failure.
+ */
+int sata_scr_write(struct ata_link *link, int reg, u32 val)
+{
+	if (ata_is_host_link(link)) {
+		if (sata_scr_valid(link))
+			return link->ap->ops->scr_write(link, reg, val);
+		return -EOPNOTSUPP;
+	}
+
+	return sata_pmp_scr_write(link, reg, val);
+}
+EXPORT_SYMBOL_GPL(sata_scr_write);
+
+/**
+ *	sata_scr_write_flush - write SCR register of the specified port and flush
+ *	@link: ATA link to write SCR for
+ *	@reg: SCR to write
+ *	@val: value to write
+ *
+ *	This function is identical to sata_scr_write() except that this
+ *	function performs flush after writing to the register.
+ *
+ *	LOCKING:
+ *	None if @link is ap->link.  Kernel thread context otherwise.
+ *
+ *	RETURNS:
+ *	0 on success, negative errno on failure.
+ */
+int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
+{
+	if (ata_is_host_link(link)) {
+		int rc;
+
+		if (sata_scr_valid(link)) {
+			rc = link->ap->ops->scr_write(link, reg, val);
+			if (rc == 0)
+				rc = link->ap->ops->scr_read(link, reg, &val);
+			return rc;
+		}
+		return -EOPNOTSUPP;
+	}
+
+	return sata_pmp_scr_write(link, reg, val);
+}
+EXPORT_SYMBOL_GPL(sata_scr_write_flush);
+
+/**
+ *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
+ *	@tf: Taskfile to convert
+ *	@pmp: Port multiplier port
+ *	@is_cmd: This FIS is for command
+ *	@fis: Buffer into which data will output
+ *
+ *	Converts a standard ATA taskfile to a Serial ATA
+ *	FIS structure (Register - Host to Device).
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
+{
+	fis[0] = 0x27;			/* Register - Host to Device FIS */
+	fis[1] = pmp & 0xf;		/* Port multiplier number*/
+	if (is_cmd)
+		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
+
+	fis[2] = tf->command;
+	fis[3] = tf->feature;
+
+	fis[4] = tf->lbal;
+	fis[5] = tf->lbam;
+	fis[6] = tf->lbah;
+	fis[7] = tf->device;
+
+	fis[8] = tf->hob_lbal;
+	fis[9] = tf->hob_lbam;
+	fis[10] = tf->hob_lbah;
+	fis[11] = tf->hob_feature;
+
+	fis[12] = tf->nsect;
+	fis[13] = tf->hob_nsect;
+	fis[14] = 0;
+	fis[15] = tf->ctl;
+
+	fis[16] = tf->auxiliary & 0xff;
+	fis[17] = (tf->auxiliary >> 8) & 0xff;
+	fis[18] = (tf->auxiliary >> 16) & 0xff;
+	fis[19] = (tf->auxiliary >> 24) & 0xff;
+}
+EXPORT_SYMBOL_GPL(ata_tf_to_fis);
+
+/**
+ *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
+ *	@fis: Buffer from which data will be input
+ *	@tf: Taskfile to output
+ *
+ *	Converts a serial ATA FIS structure to a standard ATA taskfile.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
+{
+	tf->status	= fis[2];
+	tf->error	= fis[3];
+
+	tf->lbal	= fis[4];
+	tf->lbam	= fis[5];
+	tf->lbah	= fis[6];
+	tf->device	= fis[7];
+
+	tf->hob_lbal	= fis[8];
+	tf->hob_lbam	= fis[9];
+	tf->hob_lbah	= fis[10];
+
+	tf->nsect	= fis[12];
+	tf->hob_nsect	= fis[13];
+}
+EXPORT_SYMBOL_GPL(ata_tf_from_fis);
+
+/**
+ *	sata_link_debounce - debounce SATA phy status
+ *	@link: ATA link to debounce SATA phy status for
+ *	@params: timing parameters { interval, duration, timeout } in msec
+ *	@deadline: deadline jiffies for the operation
+ *
+ *	Make sure SStatus of @link reaches stable state, determined by
+ *	holding the same value where DET is not 1 for @duration polled
+ *	every @interval, before @timeout.  Timeout constraints the
+ *	beginning of the stable state.  Because DET gets stuck at 1 on
+ *	some controllers after hot unplugging, this functions waits
+ *	until timeout then returns 0 if DET is stable at 1.
+ *
+ *	@timeout is further limited by @deadline.  The sooner of the
+ *	two is used.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep)
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_link_debounce(struct ata_link *link, const unsigned long *params,
+		       unsigned long deadline)
+{
+	unsigned long interval = params[0];
+	unsigned long duration = params[1];
+	unsigned long last_jiffies, t;
+	u32 last, cur;
+	int rc;
+
+	t = ata_deadline(jiffies, params[2]);
+	if (time_before(t, deadline))
+		deadline = t;
+
+	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
+		return rc;
+	cur &= 0xf;
+
+	last = cur;
+	last_jiffies = jiffies;
+
+	while (1) {
+		ata_msleep(link->ap, interval);
+		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
+			return rc;
+		cur &= 0xf;
+
+		/* DET stable? */
+		if (cur == last) {
+			if (cur == 1 && time_before(jiffies, deadline))
+				continue;
+			if (time_after(jiffies,
+				       ata_deadline(last_jiffies, duration)))
+				return 0;
+			continue;
+		}
+
+		/* unstable, start over */
+		last = cur;
+		last_jiffies = jiffies;
+
+		/* Check deadline.  If debouncing failed, return
+		 * -EPIPE to tell upper layer to lower link speed.
+		 */
+		if (time_after(jiffies, deadline))
+			return -EPIPE;
+	}
+}
+EXPORT_SYMBOL_GPL(sata_link_debounce);
+
+/**
+ *	sata_link_resume - resume SATA link
+ *	@link: ATA link to resume SATA
+ *	@params: timing parameters { interval, duration, timeout } in msec
+ *	@deadline: deadline jiffies for the operation
+ *
+ *	Resume SATA phy @link and debounce it.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep)
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_link_resume(struct ata_link *link, const unsigned long *params,
+		     unsigned long deadline)
+{
+	int tries = ATA_LINK_RESUME_TRIES;
+	u32 scontrol, serror;
+	int rc;
+
+	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+		return rc;
+
+	/*
+	 * Writes to SControl sometimes get ignored under certain
+	 * controllers (ata_piix SIDPR).  Make sure DET actually is
+	 * cleared.
+	 */
+	do {
+		scontrol = (scontrol & 0x0f0) | 0x300;
+		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
+			return rc;
+		/*
+		 * Some PHYs react badly if SStatus is pounded
+		 * immediately after resuming.  Delay 200ms before
+		 * debouncing.
+		 */
+		if (!(link->flags & ATA_LFLAG_NO_DEBOUNCE_DELAY))
+			ata_msleep(link->ap, 200);
+
+		/* is SControl restored correctly? */
+		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+			return rc;
+	} while ((scontrol & 0xf0f) != 0x300 && --tries);
+
+	if ((scontrol & 0xf0f) != 0x300) {
+		ata_link_warn(link, "failed to resume link (SControl %X)\n",
+			     scontrol);
+		return 0;
+	}
+
+	if (tries < ATA_LINK_RESUME_TRIES)
+		ata_link_warn(link, "link resume succeeded after %d retries\n",
+			      ATA_LINK_RESUME_TRIES - tries);
+
+	if ((rc = sata_link_debounce(link, params, deadline)))
+		return rc;
+
+	/* clear SError, some PHYs require this even for SRST to work */
+	if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
+		rc = sata_scr_write(link, SCR_ERROR, serror);
+
+	return rc != -EINVAL ? rc : 0;
+}
+EXPORT_SYMBOL_GPL(sata_link_resume);
+
+/**
+ *	sata_link_scr_lpm - manipulate SControl IPM and SPM fields
+ *	@link: ATA link to manipulate SControl for
+ *	@policy: LPM policy to configure
+ *	@spm_wakeup: initiate LPM transition to active state
+ *
+ *	Manipulate the IPM field of the SControl register of @link
+ *	according to @policy.  If @policy is ATA_LPM_MAX_POWER and
+ *	@spm_wakeup is %true, the SPM field is manipulated to wake up
+ *	the link.  This function also clears PHYRDY_CHG before
+ *	returning.
+ *
+ *	LOCKING:
+ *	EH context.
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
+		      bool spm_wakeup)
+{
+	struct ata_eh_context *ehc = &link->eh_context;
+	bool woken_up = false;
+	u32 scontrol;
+	int rc;
+
+	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
+	if (rc)
+		return rc;
+
+	switch (policy) {
+	case ATA_LPM_MAX_POWER:
+		/* disable all LPM transitions */
+		scontrol |= (0x7 << 8);
+		/* initiate transition to active state */
+		if (spm_wakeup) {
+			scontrol |= (0x4 << 12);
+			woken_up = true;
+		}
+		break;
+	case ATA_LPM_MED_POWER:
+		/* allow LPM to PARTIAL */
+		scontrol &= ~(0x1 << 8);
+		scontrol |= (0x6 << 8);
+		break;
+	case ATA_LPM_MED_POWER_WITH_DIPM:
+	case ATA_LPM_MIN_POWER_WITH_PARTIAL:
+	case ATA_LPM_MIN_POWER:
+		if (ata_link_nr_enabled(link) > 0) {
+			/* assume no restrictions on LPM transitions */
+			scontrol &= ~(0x7 << 8);
+
+			/*
+			 * If the controller does not support partial, slumber,
+			 * or devsleep, then disallow these transitions.
+			 */
+			if (link->ap->host->flags & ATA_HOST_NO_PART)
+				scontrol |= (0x1 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_SSC)
+				scontrol |= (0x2 << 8);
+
+			if (link->ap->host->flags & ATA_HOST_NO_DEVSLP)
+				scontrol |= (0x4 << 8);
+		} else {
+			/* empty port, power off */
+			scontrol &= ~0xf;
+			scontrol |= (0x1 << 2);
+		}
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+	rc = sata_scr_write(link, SCR_CONTROL, scontrol);
+	if (rc)
+		return rc;
+
+	/* give the link time to transit out of LPM state */
+	if (woken_up)
+		msleep(10);
+
+	/* clear PHYRDY_CHG from SError */
+	ehc->i.serror &= ~SERR_PHYRDY_CHG;
+	return sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
+}
+EXPORT_SYMBOL_GPL(sata_link_scr_lpm);
+
+static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
+{
+	struct ata_link *host_link = &link->ap->link;
+	u32 limit, target, spd;
+
+	limit = link->sata_spd_limit;
+
+	/* Don't configure downstream link faster than upstream link.
+	 * It doesn't speed up anything and some PMPs choke on such
+	 * configuration.
+	 */
+	if (!ata_is_host_link(link) && host_link->sata_spd)
+		limit &= (1 << host_link->sata_spd) - 1;
+
+	if (limit == UINT_MAX)
+		target = 0;
+	else
+		target = fls(limit);
+
+	spd = (*scontrol >> 4) & 0xf;
+	*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);
+
+	return spd != target;
+}
+
+/**
+ *	sata_set_spd_needed - is SATA spd configuration needed
+ *	@link: Link in question
+ *
+ *	Test whether the spd limit in SControl matches
+ *	@link->sata_spd_limit.  This function is used to determine
+ *	whether hardreset is necessary to apply SATA spd
+ *	configuration.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ *
+ *	RETURNS:
+ *	1 if SATA spd configuration is needed, 0 otherwise.
+ */
+static int sata_set_spd_needed(struct ata_link *link)
+{
+	u32 scontrol;
+
+	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
+		return 1;
+
+	return __sata_set_spd_needed(link, &scontrol);
+}
+
+/**
+ *	sata_set_spd - set SATA spd according to spd limit
+ *	@link: Link to set SATA spd for
+ *
+ *	Set SATA spd of @link according to sata_spd_limit.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ *
+ *	RETURNS:
+ *	0 if spd doesn't need to be changed, 1 if spd has been
+ *	changed.  Negative errno if SCR registers are inaccessible.
+ */
+int sata_set_spd(struct ata_link *link)
+{
+	u32 scontrol;
+	int rc;
+
+	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+		return rc;
+
+	if (!__sata_set_spd_needed(link, &scontrol))
+		return 0;
+
+	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
+		return rc;
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(sata_set_spd);
+
+/**
+ *	sata_link_hardreset - reset link via SATA phy reset
+ *	@link: link to reset
+ *	@timing: timing parameters { interval, duration, timeout } in msec
+ *	@deadline: deadline jiffies for the operation
+ *	@online: optional out parameter indicating link onlineness
+ *	@check_ready: optional callback to check link readiness
+ *
+ *	SATA phy-reset @link using DET bits of SControl register.
+ *	After hardreset, link readiness is waited upon using
+ *	ata_wait_ready() if @check_ready is specified.  LLDs are
+ *	allowed to not specify @check_ready and wait itself after this
+ *	function returns.  Device classification is LLD's
+ *	responsibility.
+ *
+ *	*@online is set to one iff reset succeeded and @link is online
+ *	after reset.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep)
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
+			unsigned long deadline,
+			bool *online, int (*check_ready)(struct ata_link *))
+{
+	u32 scontrol;
+	int rc;
+
+	if (online)
+		*online = false;
+
+	if (sata_set_spd_needed(link)) {
+		/* SATA spec says nothing about how to reconfigure
+		 * spd.  To be on the safe side, turn off phy during
+		 * reconfiguration.  This works for at least ICH7 AHCI
+		 * and Sil3124.
+		 */
+		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+			goto out;
+
+		scontrol = (scontrol & 0x0f0) | 0x304;
+
+		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
+			goto out;
+
+		sata_set_spd(link);
+	}
+
+	/* issue phy wake/reset */
+	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+		goto out;
+
+	scontrol = (scontrol & 0x0f0) | 0x301;
+
+	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
+		goto out;
+
+	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
+	 * 10.4.2 says at least 1 ms.
+	 */
+	ata_msleep(link->ap, 1);
+
+	/* bring link back */
+	rc = sata_link_resume(link, timing, deadline);
+	if (rc)
+		goto out;
+	/* if link is offline nothing more to do */
+	if (ata_phys_link_offline(link))
+		goto out;
+
+	/* Link is online.  From this point, -ENODEV too is an error. */
+	if (online)
+		*online = true;
+
+	if (sata_pmp_supported(link->ap) && ata_is_host_link(link)) {
+		/* If PMP is supported, we have to do follow-up SRST.
+		 * Some PMPs don't send D2H Reg FIS after hardreset if
+		 * the first port is empty.  Wait only for
+		 * ATA_TMOUT_PMP_SRST_WAIT.
+		 */
+		if (check_ready) {
+			unsigned long pmp_deadline;
+
+			pmp_deadline = ata_deadline(jiffies,
+						    ATA_TMOUT_PMP_SRST_WAIT);
+			if (time_after(pmp_deadline, deadline))
+				pmp_deadline = deadline;
+			ata_wait_ready(link, pmp_deadline, check_ready);
+		}
+		rc = -EAGAIN;
+		goto out;
+	}
+
+	rc = 0;
+	if (check_ready)
+		rc = ata_wait_ready(link, deadline, check_ready);
+ out:
+	if (rc && rc != -EAGAIN) {
+		/* online is set iff link is online && reset succeeded */
+		if (online)
+			*online = false;
+		ata_link_err(link, "COMRESET failed (errno=%d)\n", rc);
+	}
+	return rc;
+}
+EXPORT_SYMBOL_GPL(sata_link_hardreset);
+
+/**
+ *	ata_qc_complete_multiple - Complete multiple qcs successfully
+ *	@ap: port in question
+ *	@qc_active: new qc_active mask
+ *
+ *	Complete in-flight commands.  This functions is meant to be
+ *	called from low-level driver's interrupt routine to complete
+ *	requests normally.  ap->qc_active and @qc_active is compared
+ *	and commands are completed accordingly.
+ *
+ *	Always use this function when completing multiple NCQ commands
+ *	from IRQ handlers instead of calling ata_qc_complete()
+ *	multiple times to keep IRQ expect status properly in sync.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ *
+ *	RETURNS:
+ *	Number of completed commands on success, -errno otherwise.
+ */
+int ata_qc_complete_multiple(struct ata_port *ap, u64 qc_active)
+{
+	u64 done_mask, ap_qc_active = ap->qc_active;
+	int nr_done = 0;
+
+	/*
+	 * If the internal tag is set on ap->qc_active, then we care about
+	 * bit0 on the passed in qc_active mask. Move that bit up to match
+	 * the internal tag.
+	 */
+	if (ap_qc_active & (1ULL << ATA_TAG_INTERNAL)) {
+		qc_active |= (qc_active & 0x01) << ATA_TAG_INTERNAL;
+		qc_active ^= qc_active & 0x01;
+	}
+
+	done_mask = ap_qc_active ^ qc_active;
+
+	if (unlikely(done_mask & qc_active)) {
+		ata_port_err(ap, "illegal qc_active transition (%08llx->%08llx)\n",
+			     ap->qc_active, qc_active);
+		return -EINVAL;
+	}
+
+	while (done_mask) {
+		struct ata_queued_cmd *qc;
+		unsigned int tag = __ffs64(done_mask);
+
+		qc = ata_qc_from_tag(ap, tag);
+		if (qc) {
+			ata_qc_complete(qc);
+			nr_done++;
+		}
+		done_mask &= ~(1ULL << tag);
+	}
+
+	return nr_done;
+}
+EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
+
+/**
+ *	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;
+}
+EXPORT_SYMBOL_GPL(ata_slave_link_init);
+
+/**
+ *	sata_lpm_ignore_phy_events - test if PHY event should be ignored
+ *	@link: Link receiving the event
+ *
+ *	Test whether the received PHY event has to be ignored or not.
+ *
+ *	LOCKING:
+ *	None:
+ *
+ *	RETURNS:
+ *	True if the event has to be ignored.
+ */
+bool sata_lpm_ignore_phy_events(struct ata_link *link)
+{
+	unsigned long lpm_timeout = link->last_lpm_change +
+				    msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY);
+
+	/* if LPM is enabled, PHYRDY doesn't mean anything */
+	if (link->lpm_policy > ATA_LPM_MAX_POWER)
+		return true;
+
+	/* ignore the first PHY event after the LPM policy changed
+	 * as it is might be spurious
+	 */
+	if ((link->flags & ATA_LFLAG_CHANGED) &&
+	    time_before(jiffies, lpm_timeout))
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);
+
+static const char *ata_lpm_policy_names[] = {
+	[ATA_LPM_UNKNOWN]		= "max_performance",
+	[ATA_LPM_MAX_POWER]		= "max_performance",
+	[ATA_LPM_MED_POWER]		= "medium_power",
+	[ATA_LPM_MED_POWER_WITH_DIPM]	= "med_power_with_dipm",
+	[ATA_LPM_MIN_POWER_WITH_PARTIAL] = "min_power_with_partial",
+	[ATA_LPM_MIN_POWER]		= "min_power",
+};
+
+static ssize_t ata_scsi_lpm_store(struct device *device,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct Scsi_Host *shost = class_to_shost(device);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	struct ata_link *link;
+	struct ata_device *dev;
+	enum ata_lpm_policy policy;
+	unsigned long flags;
+
+	/* UNKNOWN is internal state, iterate from MAX_POWER */
+	for (policy = ATA_LPM_MAX_POWER;
+	     policy < ARRAY_SIZE(ata_lpm_policy_names); policy++) {
+		const char *name = ata_lpm_policy_names[policy];
+
+		if (strncmp(name, buf, strlen(name)) == 0)
+			break;
+	}
+	if (policy == ARRAY_SIZE(ata_lpm_policy_names))
+		return -EINVAL;
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	ata_for_each_link(link, ap, EDGE) {
+		ata_for_each_dev(dev, &ap->link, ENABLED) {
+			if (dev->horkage & ATA_HORKAGE_NOLPM) {
+				count = -EOPNOTSUPP;
+				goto out_unlock;
+			}
+		}
+	}
+
+	ap->target_lpm_policy = policy;
+	ata_port_schedule_eh(ap);
+out_unlock:
+	spin_unlock_irqrestore(ap->lock, flags);
+	return count;
+}
+
+static ssize_t ata_scsi_lpm_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+
+	if (ap->target_lpm_policy >= ARRAY_SIZE(ata_lpm_policy_names))
+		return -EINVAL;
+
+	return sysfs_emit(buf, "%s\n",
+			ata_lpm_policy_names[ap->target_lpm_policy]);
+}
+DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
+	    ata_scsi_lpm_show, ata_scsi_lpm_store);
+EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
+
+static ssize_t ata_ncq_prio_supported_show(struct device *device,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(device);
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_device *dev;
+	bool ncq_prio_supported;
+	int rc = 0;
+
+	spin_lock_irq(ap->lock);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (!dev)
+		rc = -ENODEV;
+	else
+		ncq_prio_supported = dev->flags & ATA_DFLAG_NCQ_PRIO;
+	spin_unlock_irq(ap->lock);
+
+	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_supported);
+}
+
+DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
+EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
+
+static ssize_t ata_ncq_prio_enable_show(struct device *device,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(device);
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_device *dev;
+	bool ncq_prio_enable;
+	int rc = 0;
+
+	spin_lock_irq(ap->lock);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (!dev)
+		rc = -ENODEV;
+	else
+		ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED;
+	spin_unlock_irq(ap->lock);
+
+	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_enable);
+}
+
+static ssize_t ata_ncq_prio_enable_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;
+	int rc = 0;
+
+	rc = kstrtol(buf, 10, &input);
+	if (rc)
+		return rc;
+	if ((input < 0) || (input > 1))
+		return -EINVAL;
+
+	ap = ata_shost_to_port(sdev->host);
+	dev = ata_scsi_find_dev(ap, sdev);
+	if (unlikely(!dev))
+		return  -ENODEV;
+
+	spin_lock_irq(ap->lock);
+
+	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {
+		rc = -EINVAL;
+		goto unlock;
+	}
+
+	if (input)
+		dev->flags |= ATA_DFLAG_NCQ_PRIO_ENABLED;
+	else
+		dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLED;
+
+unlock:
+	spin_unlock_irq(ap->lock);
+
+	return rc ? rc : len;
+}
+
+DEVICE_ATTR(ncq_prio_enable, S_IRUGO | S_IWUSR,
+	    ata_ncq_prio_enable_show, ata_ncq_prio_enable_store);
+EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_enable);
+
+static struct attribute *ata_ncq_sdev_attrs[] = {
+	&dev_attr_unload_heads.attr,
+	&dev_attr_ncq_prio_enable.attr,
+	&dev_attr_ncq_prio_supported.attr,
+	NULL
+};
+
+static const struct attribute_group ata_ncq_sdev_attr_group = {
+	.attrs = ata_ncq_sdev_attrs
+};
+
+const struct attribute_group *ata_ncq_sdev_groups[] = {
+	&ata_ncq_sdev_attr_group,
+	NULL
+};
+EXPORT_SYMBOL_GPL(ata_ncq_sdev_groups);
+
+static ssize_t
+ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	if (ap->ops->em_store && (ap->flags & ATA_FLAG_EM))
+		return ap->ops->em_store(ap, buf, count);
+	return -EINVAL;
+}
+
+static ssize_t
+ata_scsi_em_message_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+
+	if (ap->ops->em_show && (ap->flags & ATA_FLAG_EM))
+		return ap->ops->em_show(ap, buf);
+	return -EINVAL;
+}
+DEVICE_ATTR(em_message, S_IRUGO | S_IWUSR,
+		ata_scsi_em_message_show, ata_scsi_em_message_store);
+EXPORT_SYMBOL_GPL(dev_attr_em_message);
+
+static ssize_t
+ata_scsi_em_message_type_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+
+	return sysfs_emit(buf, "%d\n", ap->em_message_type);
+}
+DEVICE_ATTR(em_message_type, S_IRUGO,
+		  ata_scsi_em_message_type_show, NULL);
+EXPORT_SYMBOL_GPL(dev_attr_em_message_type);
+
+static ssize_t
+ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+
+	if (atadev && ap->ops->sw_activity_show &&
+	    (ap->flags & ATA_FLAG_SW_ACTIVITY))
+		return ap->ops->sw_activity_show(atadev, buf);
+	return -EINVAL;
+}
+
+static ssize_t
+ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
+	const char *buf, size_t count)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+	enum sw_activity val;
+	int rc;
+
+	if (atadev && ap->ops->sw_activity_store &&
+	    (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
+		val = simple_strtoul(buf, NULL, 0);
+		switch (val) {
+		case OFF: case BLINK_ON: case BLINK_OFF:
+			rc = ap->ops->sw_activity_store(atadev, val);
+			if (!rc)
+				return count;
+			else
+				return rc;
+		}
+	}
+	return -EINVAL;
+}
+DEVICE_ATTR(sw_activity, S_IWUSR | S_IRUGO, ata_scsi_activity_show,
+			ata_scsi_activity_store);
+EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
+
+/**
+ *	ata_change_queue_depth - Set a device maximum queue depth
+ *	@ap: ATA port of the target device
+ *	@dev: target ATA device
+ *	@sdev: SCSI device to configure queue depth for
+ *	@queue_depth: new queue depth
+ *
+ *	Helper to set a device maximum queue depth, usable with both libsas
+ *	and libata.
+ *
+ */
+int ata_change_queue_depth(struct ata_port *ap, struct ata_device *dev,
+			   struct scsi_device *sdev, int queue_depth)
+{
+	unsigned long flags;
+
+	if (!dev || !ata_dev_enabled(dev))
+		return sdev->queue_depth;
+
+	if (queue_depth < 1 || queue_depth == sdev->queue_depth)
+		return sdev->queue_depth;
+
+	/* NCQ enabled? */
+	spin_lock_irqsave(ap->lock, flags);
+	dev->flags &= ~ATA_DFLAG_NCQ_OFF;
+	if (queue_depth == 1 || !ata_ncq_enabled(dev)) {
+		dev->flags |= ATA_DFLAG_NCQ_OFF;
+		queue_depth = 1;
+	}
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	/* limit and apply queue depth */
+	queue_depth = min(queue_depth, sdev->host->can_queue);
+	queue_depth = min(queue_depth, ata_id_queue_depth(dev->id));
+	queue_depth = min(queue_depth, ATA_MAX_QUEUE);
+
+	if (sdev->queue_depth == queue_depth)
+		return -EINVAL;
+
+	return scsi_change_queue_depth(sdev, queue_depth);
+}
+EXPORT_SYMBOL_GPL(ata_change_queue_depth);
+
+/**
+ *	ata_scsi_change_queue_depth - SCSI callback for queue depth config
+ *	@sdev: SCSI device to configure queue depth for
+ *	@queue_depth: new queue depth
+ *
+ *	This is libata standard hostt->change_queue_depth callback.
+ *	SCSI will call into this callback when user tries to set queue
+ *	depth via sysfs.
+ *
+ *	LOCKING:
+ *	SCSI layer (we don't care)
+ *
+ *	RETURNS:
+ *	Newly configured queue depth.
+ */
+int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
+{
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+
+	return ata_change_queue_depth(ap, ata_scsi_find_dev(ap, sdev),
+				      sdev, queue_depth);
+}
+EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
+
+/**
+ *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
+ *	@host: ATA host container for all SAS ports
+ *	@port_info: Information from low-level host driver
+ *	@shost: SCSI host that the scsi device is attached to
+ *
+ *	LOCKING:
+ *	PCI/etc. bus probe sem.
+ *
+ *	RETURNS:
+ *	ata_port pointer on success / NULL on failure.
+ */
+
+struct ata_port *ata_sas_port_alloc(struct ata_host *host,
+				    struct ata_port_info *port_info,
+				    struct Scsi_Host *shost)
+{
+	struct ata_port *ap;
+
+	ap = ata_port_alloc(host);
+	if (!ap)
+		return NULL;
+
+	ap->port_no = 0;
+	ap->lock = &host->lock;
+	ap->pio_mask = port_info->pio_mask;
+	ap->mwdma_mask = port_info->mwdma_mask;
+	ap->udma_mask = port_info->udma_mask;
+	ap->flags |= port_info->flags;
+	ap->ops = port_info->port_ops;
+	ap->cbl = ATA_CBL_SATA;
+
+	return ap;
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
+
+/**
+ *	ata_sas_port_start - Set port up for dma.
+ *	@ap: Port to initialize
+ *
+ *	Called just after data structures for each port are
+ *	initialized.
+ *
+ *	May be used as the port_start() entry in ata_port_operations.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+int ata_sas_port_start(struct ata_port *ap)
+{
+	/*
+	 * the port is marked as frozen at allocation time, but if we don't
+	 * have new eh, we won't thaw it
+	 */
+	if (!ap->ops->error_handler)
+		ap->pflags &= ~ATA_PFLAG_FROZEN;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_start);
+
+/**
+ *	ata_sas_port_stop - Undo ata_sas_port_start()
+ *	@ap: Port to shut down
+ *
+ *	May be used as the port_stop() entry in ata_port_operations.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+void ata_sas_port_stop(struct ata_port *ap)
+{
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_stop);
+
+/**
+ * ata_sas_async_probe - simply schedule probing and return
+ * @ap: Port to probe
+ *
+ * For batch scheduling of probe for sas attached ata devices, assumes
+ * the port has already been through ata_sas_port_init()
+ */
+void ata_sas_async_probe(struct ata_port *ap)
+{
+	__ata_port_probe(ap);
+}
+EXPORT_SYMBOL_GPL(ata_sas_async_probe);
+
+int ata_sas_sync_probe(struct ata_port *ap)
+{
+	return ata_port_probe(ap);
+}
+EXPORT_SYMBOL_GPL(ata_sas_sync_probe);
+
+
+/**
+ *	ata_sas_port_init - Initialize a SATA device
+ *	@ap: SATA port to initialize
+ *
+ *	LOCKING:
+ *	PCI/etc. bus probe sem.
+ *
+ *	RETURNS:
+ *	Zero on success, non-zero on error.
+ */
+
+int ata_sas_port_init(struct ata_port *ap)
+{
+	int rc = ap->ops->port_start(ap);
+
+	if (rc)
+		return rc;
+	ap->print_id = atomic_inc_return(&ata_print_id);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_init);
+
+int ata_sas_tport_add(struct device *parent, struct ata_port *ap)
+{
+	return ata_tport_add(parent, ap);
+}
+EXPORT_SYMBOL_GPL(ata_sas_tport_add);
+
+void ata_sas_tport_delete(struct ata_port *ap)
+{
+	ata_tport_delete(ap);
+}
+EXPORT_SYMBOL_GPL(ata_sas_tport_delete);
+
+/**
+ *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
+ *	@ap: SATA port to destroy
+ *
+ */
+
+void ata_sas_port_destroy(struct ata_port *ap)
+{
+	if (ap->ops->port_stop)
+		ap->ops->port_stop(ap);
+	kfree(ap);
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
+
+/**
+ *	ata_sas_slave_configure - Default slave_config routine for libata devices
+ *	@sdev: SCSI device to configure
+ *	@ap: ATA port to which SCSI device is attached
+ *
+ *	RETURNS:
+ *	Zero.
+ */
+
+int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
+{
+	ata_scsi_sdev_config(sdev);
+	ata_scsi_dev_config(sdev, ap->link.device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
+
+/**
+ *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
+ *	@cmd: SCSI command to be sent
+ *	@ap:	ATA port to which the command is being sent
+ *
+ *	RETURNS:
+ *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
+ *	0 otherwise.
+ */
+
+int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
+{
+	int rc = 0;
+
+	if (likely(ata_dev_enabled(ap->link.device)))
+		rc = __ata_scsi_queuecmd(cmd, ap->link.device);
+	else {
+		cmd->result = (DID_BAD_TARGET << 16);
+		scsi_done(cmd);
+	}
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
+
+/**
+ *	sata_async_notification - SATA async notification handler
+ *	@ap: ATA port where async notification is received
+ *
+ *	Handler to be called when async notification via SDB FIS is
+ *	received.  This function schedules EH if necessary.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ *
+ *	RETURNS:
+ *	1 if EH is scheduled, 0 otherwise.
+ */
+int sata_async_notification(struct ata_port *ap)
+{
+	u32 sntf;
+	int rc;
+
+	if (!(ap->flags & ATA_FLAG_AN))
+		return 0;
+
+	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
+	if (rc == 0)
+		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
+
+	if (!sata_pmp_attached(ap) || rc) {
+		/* PMP is not attached or SNTF is not available */
+		if (!sata_pmp_attached(ap)) {
+			/* PMP is not attached.  Check whether ATAPI
+			 * AN is configured.  If so, notify media
+			 * change.
+			 */
+			struct ata_device *dev = ap->link.device;
+
+			if ((dev->class == ATA_DEV_ATAPI) &&
+			    (dev->flags & ATA_DFLAG_AN))
+				ata_scsi_media_change_notify(dev);
+			return 0;
+		} else {
+			/* PMP is attached but SNTF is not available.
+			 * ATAPI async media change notification is
+			 * not used.  The PMP must be reporting PHY
+			 * status change, schedule EH.
+			 */
+			ata_port_schedule_eh(ap);
+			return 1;
+		}
+	} else {
+		/* PMP is attached and SNTF is available */
+		struct ata_link *link;
+
+		/* check and notify ATAPI AN */
+		ata_for_each_link(link, ap, EDGE) {
+			if (!(sntf & (1 << link->pmp)))
+				continue;
+
+			if ((link->device->class == ATA_DEV_ATAPI) &&
+			    (link->device->flags & ATA_DFLAG_AN))
+				ata_scsi_media_change_notify(link->device);
+		}
+
+		/* If PMP is reporting that PHY status of some
+		 * downstream ports has changed, schedule EH.
+		 */
+		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
+			ata_port_schedule_eh(ap);
+			return 1;
+		}
+
+		return 0;
+	}
+}
+EXPORT_SYMBOL_GPL(sata_async_notification);
+
+/**
+ *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
+ *	@dev: Device to read log page 10h from
+ *	@tag: Resulting tag of the failed command
+ *	@tf: Resulting taskfile registers of the failed command
+ *
+ *	Read log page 10h to obtain NCQ error details and clear error
+ *	condition.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+static int ata_eh_read_log_10h(struct ata_device *dev,
+			       int *tag, struct ata_taskfile *tf)
+{
+	u8 *buf = dev->link->ap->sector_buf;
+	unsigned int err_mask;
+	u8 csum;
+	int i;
+
+	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, 0, buf, 1);
+	if (err_mask)
+		return -EIO;
+
+	csum = 0;
+	for (i = 0; i < ATA_SECT_SIZE; i++)
+		csum += buf[i];
+	if (csum)
+		ata_dev_warn(dev, "invalid checksum 0x%x on log page 10h\n",
+			     csum);
+
+	if (buf[0] & 0x80)
+		return -ENOENT;
+
+	*tag = buf[0] & 0x1f;
+
+	tf->status = buf[2];
+	tf->error = buf[3];
+	tf->lbal = buf[4];
+	tf->lbam = buf[5];
+	tf->lbah = buf[6];
+	tf->device = buf[7];
+	tf->hob_lbal = buf[8];
+	tf->hob_lbam = buf[9];
+	tf->hob_lbah = buf[10];
+	tf->nsect = buf[12];
+	tf->hob_nsect = buf[13];
+	if (dev->class == ATA_DEV_ZAC && ata_id_has_ncq_autosense(dev->id) &&
+	    (tf->status & ATA_SENSE))
+		tf->auxiliary = buf[14] << 16 | buf[15] << 8 | buf[16];
+
+	return 0;
+}
+
+/**
+ *	ata_eh_analyze_ncq_error - analyze NCQ error
+ *	@link: ATA link to analyze NCQ error for
+ *
+ *	Read log page 10h, determine the offending qc and acquire
+ *	error status TF.  For NCQ device errors, all LLDDs have to do
+ *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
+ *	care of the rest.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ */
+void ata_eh_analyze_ncq_error(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_eh_context *ehc = &link->eh_context;
+	struct ata_device *dev = link->device;
+	struct ata_queued_cmd *qc;
+	struct ata_taskfile tf;
+	int tag, rc;
+
+	/* if frozen, we can't do much */
+	if (ap->pflags & ATA_PFLAG_FROZEN)
+		return;
+
+	/* is it NCQ device error? */
+	if (!link->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
+		return;
+
+	/* has LLDD analyzed already? */
+	ata_qc_for_each_raw(ap, qc, tag) {
+		if (!(qc->flags & ATA_QCFLAG_FAILED))
+			continue;
+
+		if (qc->err_mask)
+			return;
+	}
+
+	/* okay, this error is ours */
+	memset(&tf, 0, sizeof(tf));
+	rc = ata_eh_read_log_10h(dev, &tag, &tf);
+	if (rc) {
+		ata_link_err(link, "failed to read log page 10h (errno=%d)\n",
+			     rc);
+		return;
+	}
+
+	if (!(link->sactive & (1 << tag))) {
+		ata_link_err(link, "log page 10h reported inactive tag %d\n",
+			     tag);
+		return;
+	}
+
+	/* we've got the perpetrator, condemn it */
+	qc = __ata_qc_from_tag(ap, tag);
+	memcpy(&qc->result_tf, &tf, sizeof(tf));
+	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
+	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
+
+	/*
+	 * If the device supports NCQ autosense, ata_eh_read_log_10h() will have
+	 * stored the sense data in qc->result_tf.auxiliary.
+	 */
+	if (qc->result_tf.auxiliary) {
+		char sense_key, asc, ascq;
+
+		sense_key = (qc->result_tf.auxiliary >> 16) & 0xff;
+		asc = (qc->result_tf.auxiliary >> 8) & 0xff;
+		ascq = qc->result_tf.auxiliary & 0xff;
+		ata_scsi_set_sense(dev, qc->scsicmd, sense_key, asc, ascq);
+		ata_scsi_set_sense_information(dev, qc->scsicmd,
+					       &qc->result_tf);
+		qc->flags |= ATA_QCFLAG_SENSE_VALID;
+	}
+
+	ehc->i.err_mask &= ~AC_ERR_DEV;
+}
+EXPORT_SYMBOL_GPL(ata_eh_analyze_ncq_error);