Merge tag 'riscv-for-linus-5.15-mw0' of git://git.kernel.org/pub/scm/linux/kernel...

[platform/kernel/linux-starfive.git] / drivers / ata / libata-sata.c

// 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->command     = fis[2];       /* status */
        tf->feature     = fis[3];       /* error */

        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_DB_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)
                        /* no restrictions on LPM transitions */
                        scontrol &= ~(0x7 << 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;

        DPRINTK("ENTER\n");

        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);
        }
        DPRINTK("EXIT, rc=%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 snprintf(buf, PAGE_SIZE, "%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_ENABLE;
        spin_unlock_irq(ap->lock);

        return rc ? rc : snprintf(buf, 20, "%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_ENABLE;
        else
                dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;

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);

struct device_attribute *ata_ncq_sdev_attrs[] = {
        &dev_attr_unload_heads,
        &dev_attr_ncq_prio_enable,
        &dev_attr_ncq_prio_supported,
        NULL
};
EXPORT_SYMBOL_GPL(ata_ncq_sdev_attrs);

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 snprintf(buf, 23, "%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 - helper for ata_scsi_change_queue_depth
 *      @ap: ATA port to which the device change the queue depth
 *      @sdev: SCSI device to configure queue depth for
 *      @queue_depth: new queue depth
 *
 *      libsas and libata have different approaches for associating a sdev to
 *      its ata_port.
 *
 */
int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
                             int queue_depth)
{
        struct ata_device *dev;
        unsigned long flags;

        if (queue_depth < 1 || queue_depth == sdev->queue_depth)
                return sdev->queue_depth;

        dev = ata_scsi_find_dev(ap, sdev);
        if (!dev || !ata_dev_enabled(dev))
                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, 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;

        ata_scsi_dump_cdb(ap, cmd);

        if (likely(ata_dev_enabled(ap->link.device)))
                rc = __ata_scsi_queuecmd(cmd, ap->link.device);
        else {
                cmd->result = (DID_BAD_TARGET << 16);
                cmd->scsi_done(cmd);
        }
        return rc;
}
EXPORT_SYMBOL_GPL(ata_sas_queuecmd);

int ata_sas_allocate_tag(struct ata_port *ap)
{
        unsigned int max_queue = ap->host->n_tags;
        unsigned int i, tag;

        for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) {
                tag = tag < max_queue ? tag : 0;

                /* the last tag is reserved for internal command. */
                if (ata_tag_internal(tag))
                        continue;

                if (!test_and_set_bit(tag, &ap->sas_tag_allocated)) {
                        ap->sas_last_tag = tag;
                        return tag;
                }
        }
        return -1;
}

void ata_sas_free_tag(unsigned int tag, struct ata_port *ap)
{
        clear_bit(tag, &ap->sas_tag_allocated);
}

/**
 *      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->command = buf[2];
        tf->feature = 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->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 (dev->class == ATA_DEV_ZAC &&
            ((qc->result_tf.command & ATA_SENSE) || 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);