libata-core.c

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/*
 *  libata-core.c - helper library for ATA
 *
 *  Maintained by:  Jeff Garzik <[email protected]>
 *              Please ALWAYS copy [email protected]
 *          on emails.
 *
 *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
 *  Copyright 2003-2004 Jeff Garzik
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/DocBook/libata.*
 *
 *  Hardware documentation available from http://www.t13.org/ and
 *  http://www.sata-io.org/
 *
 *  Standards documents from:
 *  http://www.t13.org (ATA standards, PCI DMA IDE spec)
 *  http://www.t10.org (SCSI MMC - for ATAPI MMC)
 *  http://www.sata-io.org (SATA)
 *  http://www.compactflash.org (CF)
 *  http://www.qic.org (QIC157 - Tape and DSC)
 *  http://www.ce-ata.org (CE-ATA: not supported)
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/suspend.h>
#include <linux/workqueue.h>
#include <linux/scatterlist.h>
#include <linux/io.h>
#include <linux/async.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <asm/byteorder.h>
#include <linux/cdrom.h>
#include <linux/ratelimit.h>
#include <linux/pm_runtime.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 };
const unsigned long sata_deb_timing_hotplug[]       = {  25,  500, 2000 };
const unsigned long sata_deb_timing_long[]      = { 100, 2000, 5000 };

const struct ata_port_operations ata_base_port_ops = {
    .prereset       = ata_std_prereset,
    .postreset      = ata_std_postreset,
    .error_handler      = ata_std_error_handler,
    .sched_eh       = ata_std_sched_eh,
    .end_eh         = ata_std_end_eh,
};

const struct ata_port_operations sata_port_ops = {
    .inherits       = &ata_base_port_ops,

    .qc_defer       = ata_std_qc_defer,
    .hardreset      = sata_std_hardreset,
};

static unsigned int ata_dev_init_params(struct ata_device *dev,
                    u16 heads, u16 sectors);
static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
static void ata_dev_xfermask(struct ata_device *dev);
static unsigned long ata_dev_blacklisted(const struct ata_device *dev);

atomic_t ata_print_id = ATOMIC_INIT(0);

struct ata_force_param {
    const char  *name;
    unsigned int    cbl;
    int     spd_limit;
    unsigned long   xfer_mask;
    unsigned int    horkage_on;
    unsigned int    horkage_off;
    unsigned int    lflags;
};

struct ata_force_ent {
    int         port;
    int         device;
    struct ata_force_param  param;
};

static struct ata_force_ent *ata_force_tbl;
static int ata_force_tbl_size;

static char ata_force_param_buf[PAGE_SIZE] __initdata;
/* param_buf is thrown away after initialization, disallow read */
module_param_string(force, ata_force_param_buf, sizeof(ata_force_param_buf), 0);
MODULE_PARM_DESC(force, "Force ATA configurations including cable type, link speed and transfer mode (see Documentation/kernel-parameters.txt for details)");

static int atapi_enabled = 1;
module_param(atapi_enabled, int, 0444);
MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on [default])");

static int atapi_dmadir = 0;
module_param(atapi_dmadir, int, 0444);
MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off [default], 1=on)");

int atapi_passthru16 = 1;
module_param(atapi_passthru16, int, 0444);
MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");

int libata_fua = 0;
module_param_named(fua, libata_fua, int, 0444);
MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");

static int ata_ignore_hpa;
module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
MODULE_PARM_DESC(ignore_hpa, "Ignore HPA limit (0=keep BIOS limits, 1=ignore limits, using full disk)");

static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
module_param_named(dma, libata_dma_mask, int, 0444);
MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");

static int ata_probe_timeout;
module_param(ata_probe_timeout, int, 0444);
MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");

int libata_noacpi = 0;
module_param_named(noacpi, libata_noacpi, int, 0444);
MODULE_PARM_DESC(noacpi, "Disable the use of ACPI in probe/suspend/resume (0=off [default], 1=on)");

int libata_allow_tpm = 0;
module_param_named(allow_tpm, libata_allow_tpm, int, 0444);
MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands (0=off [default], 1=on)");

static int atapi_an;
module_param(atapi_an, int, 0444);
MODULE_PARM_DESC(atapi_an, "Enable ATAPI AN media presence notification (0=0ff [default], 1=on)");

MODULE_AUTHOR("Jeff Garzik");
MODULE_DESCRIPTION("Library module for ATA devices");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);


static bool ata_sstatus_online(u32 sstatus)
{
    return (sstatus & 0xf) == 0x3;
}

struct ata_link *ata_link_next(struct ata_link *link, struct ata_port *ap,
                   enum ata_link_iter_mode mode)
{
    BUG_ON(mode != ATA_LITER_EDGE &&
           mode != ATA_LITER_PMP_FIRST && mode != ATA_LITER_HOST_FIRST);

    /* NULL link indicates start of iteration */
    if (!link)
        switch (mode) {
        case ATA_LITER_EDGE:
        case ATA_LITER_PMP_FIRST:
            if (sata_pmp_attached(ap))
                return ap->pmp_link;
            /* fall through */
        case ATA_LITER_HOST_FIRST:
            return &ap->link;
        }

    /* we just iterated over the host link, what's next? */
    if (link == &ap->link)
        switch (mode) {
        case ATA_LITER_HOST_FIRST:
            if (sata_pmp_attached(ap))
                return ap->pmp_link;
            /* fall through */
        case ATA_LITER_PMP_FIRST:
            if (unlikely(ap->slave_link))
                return ap->slave_link;
            /* fall through */
        case ATA_LITER_EDGE:
            return NULL;
        }

    /* slave_link excludes PMP */
    if (unlikely(link == ap->slave_link))
        return NULL;

    /* we were over a PMP link */
    if (++link < ap->pmp_link + ap->nr_pmp_links)
        return link;

    if (mode == ATA_LITER_PMP_FIRST)
        return &ap->link;

    return NULL;
}

struct ata_device *ata_dev_next(struct ata_device *dev, struct ata_link *link,
                enum ata_dev_iter_mode mode)
{
    BUG_ON(mode != ATA_DITER_ENABLED && mode != ATA_DITER_ENABLED_REVERSE &&
           mode != ATA_DITER_ALL && mode != ATA_DITER_ALL_REVERSE);

    /* NULL dev indicates start of iteration */
    if (!dev)
        switch (mode) {
        case ATA_DITER_ENABLED:
        case ATA_DITER_ALL:
            dev = link->device;
            goto check;
        case ATA_DITER_ENABLED_REVERSE:
        case ATA_DITER_ALL_REVERSE:
            dev = link->device + ata_link_max_devices(link) - 1;
            goto check;
        }

 next:
    /* move to the next one */
    switch (mode) {
    case ATA_DITER_ENABLED:
    case ATA_DITER_ALL:
        if (++dev < link->device + ata_link_max_devices(link))
            goto check;
        return NULL;
    case ATA_DITER_ENABLED_REVERSE:
    case ATA_DITER_ALL_REVERSE:
        if (--dev >= link->device)
            goto check;
        return NULL;
    }

 check:
    if ((mode == ATA_DITER_ENABLED || mode == ATA_DITER_ENABLED_REVERSE) &&
        !ata_dev_enabled(dev))
        goto next;
    return dev;
}

struct ata_link *ata_dev_phys_link(struct ata_device *dev)
{
    struct ata_port *ap = dev->link->ap;

    if (!ap->slave_link)
        return dev->link;
    if (!dev->devno)
        return &ap->link;
    return ap->slave_link;
}

void ata_force_cbl(struct ata_port *ap)
{
    int i;

    for (i = ata_force_tbl_size - 1; i >= 0; i--) {
        const struct ata_force_ent *fe = &ata_force_tbl[i];

        if (fe->port != -1 && fe->port != ap->print_id)
            continue;

        if (fe->param.cbl == ATA_CBL_NONE)
            continue;

        ap->cbl = fe->param.cbl;
        ata_port_notice(ap, "FORCE: cable set to %s\n", fe->param.name);
        return;
    }
}

static void ata_force_link_limits(struct ata_link *link)
{
    bool did_spd = false;
    int linkno = link->pmp;
    int i;

    if (ata_is_host_link(link))
        linkno += 15;

    for (i = ata_force_tbl_size - 1; i >= 0; i--) {
        const struct ata_force_ent *fe = &ata_force_tbl[i];

        if (fe->port != -1 && fe->port != link->ap->print_id)
            continue;

        if (fe->device != -1 && fe->device != linkno)
            continue;

        /* only honor the first spd limit */
        if (!did_spd && fe->param.spd_limit) {
            link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
            ata_link_notice(link, "FORCE: PHY spd limit set to %s\n",
                    fe->param.name);
            did_spd = true;
        }

        /* let lflags stack */
        if (fe->param.lflags) {
            link->flags |= fe->param.lflags;
            ata_link_notice(link,
                    "FORCE: link flag 0x%x forced -> 0x%x\n",
                    fe->param.lflags, link->flags);
        }
    }
}

static void ata_force_xfermask(struct ata_device *dev)
{
    int devno = dev->link->pmp + dev->devno;
    int alt_devno = devno;
    int i;

    /* allow n.15/16 for devices attached to host port */
    if (ata_is_host_link(dev->link))
        alt_devno += 15;

    for (i = ata_force_tbl_size - 1; i >= 0; i--) {
        const struct ata_force_ent *fe = &ata_force_tbl[i];
        unsigned long pio_mask, mwdma_mask, udma_mask;

        if (fe->port != -1 && fe->port != dev->link->ap->print_id)
            continue;

        if (fe->device != -1 && fe->device != devno &&
            fe->device != alt_devno)
            continue;

        if (!fe->param.xfer_mask)
            continue;

        ata_unpack_xfermask(fe->param.xfer_mask,
                    &pio_mask, &mwdma_mask, &udma_mask);
        if (udma_mask)
            dev->udma_mask = udma_mask;
        else if (mwdma_mask) {
            dev->udma_mask = 0;
            dev->mwdma_mask = mwdma_mask;
        } else {
            dev->udma_mask = 0;
            dev->mwdma_mask = 0;
            dev->pio_mask = pio_mask;
        }

        ata_dev_notice(dev, "FORCE: xfer_mask set to %s\n",
                   fe->param.name);
        return;
    }
}

static void ata_force_horkage(struct ata_device *dev)
{
    int devno = dev->link->pmp + dev->devno;
    int alt_devno = devno;
    int i;

    /* allow n.15/16 for devices attached to host port */
    if (ata_is_host_link(dev->link))
        alt_devno += 15;

    for (i = 0; i < ata_force_tbl_size; i++) {
        const struct ata_force_ent *fe = &ata_force_tbl[i];

        if (fe->port != -1 && fe->port != dev->link->ap->print_id)
            continue;

        if (fe->device != -1 && fe->device != devno &&
            fe->device != alt_devno)
            continue;

        if (!(~dev->horkage & fe->param.horkage_on) &&
            !(dev->horkage & fe->param.horkage_off))
            continue;

        dev->horkage |= fe->param.horkage_on;
        dev->horkage &= ~fe->param.horkage_off;

        ata_dev_notice(dev, "FORCE: horkage modified (%s)\n",
                   fe->param.name);
    }
}

int atapi_cmd_type(u8 opcode)
{
    switch (opcode) {
    case GPCMD_READ_10:
    case GPCMD_READ_12:
        return ATAPI_READ;

    case GPCMD_WRITE_10:
    case GPCMD_WRITE_12:
    case GPCMD_WRITE_AND_VERIFY_10:
        return ATAPI_WRITE;

    case GPCMD_READ_CD:
    case GPCMD_READ_CD_MSF:
        return ATAPI_READ_CD;

    case ATA_16:
    case ATA_12:
        if (atapi_passthru16)
            return ATAPI_PASS_THRU;
        /* fall thru */
    default:
        return ATAPI_MISC;
    }
}

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] = 0;
    fis[17] = 0;
    fis[18] = 0;
    fis[19] = 0;
}

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];
}

static const u8 ata_rw_cmds[] = {
    /* pio multi */
    ATA_CMD_READ_MULTI,
    ATA_CMD_WRITE_MULTI,
    ATA_CMD_READ_MULTI_EXT,
    ATA_CMD_WRITE_MULTI_EXT,
    0,
    0,
    0,
    ATA_CMD_WRITE_MULTI_FUA_EXT,
    /* pio */
    ATA_CMD_PIO_READ,
    ATA_CMD_PIO_WRITE,
    ATA_CMD_PIO_READ_EXT,
    ATA_CMD_PIO_WRITE_EXT,
    0,
    0,
    0,
    0,
    /* dma */
    ATA_CMD_READ,
    ATA_CMD_WRITE,
    ATA_CMD_READ_EXT,
    ATA_CMD_WRITE_EXT,
    0,
    0,
    0,
    ATA_CMD_WRITE_FUA_EXT
};

static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
{
    u8 cmd;

    int index, fua, lba48, write;

    fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
    lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
    write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;

    if (dev->flags & ATA_DFLAG_PIO) {
        tf->protocol = ATA_PROT_PIO;
        index = dev->multi_count ? 0 : 8;
    } else if (lba48 && (dev->link->ap->flags & ATA_FLAG_PIO_LBA48)) {
        /* Unable to use DMA due to host limitation */
        tf->protocol = ATA_PROT_PIO;
        index = dev->multi_count ? 0 : 8;
    } else {
        tf->protocol = ATA_PROT_DMA;
        index = 16;
    }

    cmd = ata_rw_cmds[index + fua + lba48 + write];
    if (cmd) {
        tf->command = cmd;
        return 0;
    }
    return -1;
}

u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
{
    u64 block = 0;

    if (tf->flags & ATA_TFLAG_LBA) {
        if (tf->flags & ATA_TFLAG_LBA48) {
            block |= (u64)tf->hob_lbah << 40;
            block |= (u64)tf->hob_lbam << 32;
            block |= (u64)tf->hob_lbal << 24;
        } else
            block |= (tf->device & 0xf) << 24;

        block |= tf->lbah << 16;
        block |= tf->lbam << 8;
        block |= tf->lbal;
    } else {
        u32 cyl, head, sect;

        cyl = tf->lbam | (tf->lbah << 8);
        head = tf->device & 0xf;
        sect = tf->lbal;

        if (!sect) {
            ata_dev_warn(dev,
                     "device reported invalid CHS sector 0\n");
            sect = 1; /* oh well */
        }

        block = (cyl * dev->heads + head) * dev->sectors + sect - 1;
    }

    return block;
}

int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
            u64 block, u32 n_block, unsigned int tf_flags,
            unsigned int tag)
{
    tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
    tf->flags |= tf_flags;

    if (ata_ncq_enabled(dev) && likely(tag != ATA_TAG_INTERNAL)) {
        /* yay, NCQ */
        if (!lba_48_ok(block, n_block))
            return -ERANGE;

        tf->protocol = ATA_PROT_NCQ;
        tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;

        if (tf->flags & ATA_TFLAG_WRITE)
            tf->command = ATA_CMD_FPDMA_WRITE;
        else
            tf->command = ATA_CMD_FPDMA_READ;

        tf->nsect = tag << 3;
        tf->hob_feature = (n_block >> 8) & 0xff;
        tf->feature = n_block & 0xff;

        tf->hob_lbah = (block >> 40) & 0xff;
        tf->hob_lbam = (block >> 32) & 0xff;
        tf->hob_lbal = (block >> 24) & 0xff;
        tf->lbah = (block >> 16) & 0xff;
        tf->lbam = (block >> 8) & 0xff;
        tf->lbal = block & 0xff;

        tf->device = ATA_LBA;
        if (tf->flags & ATA_TFLAG_FUA)
            tf->device |= 1 << 7;
    } else if (dev->flags & ATA_DFLAG_LBA) {
        tf->flags |= ATA_TFLAG_LBA;

        if (lba_28_ok(block, n_block)) {
            /* use LBA28 */
            tf->device |= (block >> 24) & 0xf;
        } else if (lba_48_ok(block, n_block)) {
            if (!(dev->flags & ATA_DFLAG_LBA48))
                return -ERANGE;

            /* use LBA48 */
            tf->flags |= ATA_TFLAG_LBA48;

            tf->hob_nsect = (n_block >> 8) & 0xff;

            tf->hob_lbah = (block >> 40) & 0xff;
            tf->hob_lbam = (block >> 32) & 0xff;
            tf->hob_lbal = (block >> 24) & 0xff;
        } else
            /* request too large even for LBA48 */
            return -ERANGE;

        if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
            return -EINVAL;

        tf->nsect = n_block & 0xff;

        tf->lbah = (block >> 16) & 0xff;
        tf->lbam = (block >> 8) & 0xff;
        tf->lbal = block & 0xff;

        tf->device |= ATA_LBA;
    } else {
        /* CHS */
        u32 sect, head, cyl, track;

        /* The request -may- be too large for CHS addressing. */
        if (!lba_28_ok(block, n_block))
            return -ERANGE;

        if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
            return -EINVAL;

        /* Convert LBA to CHS */
        track = (u32)block / dev->sectors;
        cyl   = track / dev->heads;
        head  = track % dev->heads;
        sect  = (u32)block % dev->sectors + 1;

        DPRINTK("block %u track %u cyl %u head %u sect %u\n",
            (u32)block, track, cyl, head, sect);

        /* Check whether the converted CHS can fit.
           Cylinder: 0-65535
           Head: 0-15
           Sector: 1-255*/
        if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
            return -ERANGE;

        tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
        tf->lbal = sect;
        tf->lbam = cyl;
        tf->lbah = cyl >> 8;
        tf->device |= head;
    }

    return 0;
}

unsigned long ata_pack_xfermask(unsigned long pio_mask,
                unsigned long mwdma_mask,
                unsigned long udma_mask)
{
    return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
        ((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
        ((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
}

void ata_unpack_xfermask(unsigned long xfer_mask, unsigned long *pio_mask,
             unsigned long *mwdma_mask, unsigned long *udma_mask)
{
    if (pio_mask)
        *pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
    if (mwdma_mask)
        *mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
    if (udma_mask)
        *udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
}

static const struct ata_xfer_ent {
    int shift, bits;
    u8 base;
} ata_xfer_tbl[] = {
    { ATA_SHIFT_PIO, ATA_NR_PIO_MODES, XFER_PIO_0 },
    { ATA_SHIFT_MWDMA, ATA_NR_MWDMA_MODES, XFER_MW_DMA_0 },
    { ATA_SHIFT_UDMA, ATA_NR_UDMA_MODES, XFER_UDMA_0 },
    { -1, },
};

u8 ata_xfer_mask2mode(unsigned long xfer_mask)
{
    int highbit = fls(xfer_mask) - 1;
    const struct ata_xfer_ent *ent;

    for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
        if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
            return ent->base + highbit - ent->shift;
    return 0xff;
}

unsigned long ata_xfer_mode2mask(u8 xfer_mode)
{
    const struct ata_xfer_ent *ent;

    for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
        if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
            return ((2 << (ent->shift + xfer_mode - ent->base)) - 1)
                & ~((1 << ent->shift) - 1);
    return 0;
}

int ata_xfer_mode2shift(unsigned long xfer_mode)
{
    const struct ata_xfer_ent *ent;

    for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
        if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
            return ent->shift;
    return -1;
}

const char *ata_mode_string(unsigned long xfer_mask)
{
    static const char * const xfer_mode_str[] = {
        "PIO0",
        "PIO1",
        "PIO2",
        "PIO3",
        "PIO4",
        "PIO5",
        "PIO6",
        "MWDMA0",
        "MWDMA1",
        "MWDMA2",
        "MWDMA3",
        "MWDMA4",
        "UDMA/16",
        "UDMA/25",
        "UDMA/33",
        "UDMA/44",
        "UDMA/66",
        "UDMA/100",
        "UDMA/133",
        "UDMA7",
    };
    int highbit;

    highbit = fls(xfer_mask) - 1;
    if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
        return xfer_mode_str[highbit];
    return "<n/a>";
}

const char *sata_spd_string(unsigned int spd)
{
    static const char * const spd_str[] = {
        "1.5 Gbps",
        "3.0 Gbps",
        "6.0 Gbps",
    };

    if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
        return "<unknown>";
    return spd_str[spd - 1];
}

unsigned int ata_dev_classify(const struct ata_taskfile *tf)
{
    /* Apple's open source Darwin code hints that some devices only
     * put a proper signature into the LBA mid/high registers,
     * So, we only check those.  It's sufficient for uniqueness.
     *
     * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
     * signatures for ATA and ATAPI devices attached on SerialATA,
     * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
     * spec has never mentioned about using different signatures
     * for ATA/ATAPI devices.  Then, Serial ATA II: Port
     * Multiplier specification began to use 0x69/0x96 to identify
     * port multpliers and 0x3c/0xc3 to identify SEMB device.
     * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
     * 0x69/0x96 shortly and described them as reserved for
     * SerialATA.
     *
     * We follow the current spec and consider that 0x69/0x96
     * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
     * Unfortunately, WDC WD1600JS-62MHB5 (a hard drive) reports
     * SEMB signature.  This is worked around in
     * ata_dev_read_id().
     */
    if ((tf->lbam == 0) && (tf->lbah == 0)) {
        DPRINTK("found ATA device by sig\n");
        return ATA_DEV_ATA;
    }

    if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
        DPRINTK("found ATAPI device by sig\n");
        return ATA_DEV_ATAPI;
    }

    if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
        DPRINTK("found PMP device by sig\n");
        return ATA_DEV_PMP;
    }

    if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
        DPRINTK("found SEMB device by sig (could be ATA device)\n");
        return ATA_DEV_SEMB;
    }

    DPRINTK("unknown device\n");
    return ATA_DEV_UNKNOWN;
}

void ata_id_string(const u16 *id, unsigned char *s,
           unsigned int ofs, unsigned int len)
{
    unsigned int c;

    BUG_ON(len & 1);

    while (len > 0) {
        c = id[ofs] >> 8;
        *s = c;
        s++;

        c = id[ofs] & 0xff;
        *s = c;
        s++;

        ofs++;
        len -= 2;
    }
}

void ata_id_c_string(const u16 *id, unsigned char *s,
             unsigned int ofs, unsigned int len)
{
    unsigned char *p;

    ata_id_string(id, s, ofs, len - 1);

    p = s + strnlen(s, len - 1);
    while (p > s && p[-1] == ' ')
        p--;
    *p = '\0';
}

static u64 ata_id_n_sectors(const u16 *id)
{
    if (ata_id_has_lba(id)) {
        if (ata_id_has_lba48(id))
            return ata_id_u64(id, ATA_ID_LBA_CAPACITY_2);
        else
            return ata_id_u32(id, ATA_ID_LBA_CAPACITY);
    } else {
        if (ata_id_current_chs_valid(id))
            return id[ATA_ID_CUR_CYLS] * id[ATA_ID_CUR_HEADS] *
                   id[ATA_ID_CUR_SECTORS];
        else
            return id[ATA_ID_CYLS] * id[ATA_ID_HEADS] *
                   id[ATA_ID_SECTORS];
    }
}

u64 ata_tf_to_lba48(const struct ata_taskfile *tf)
{
    u64 sectors = 0;

    sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
    sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
    sectors |= ((u64)(tf->hob_lbal & 0xff)) << 24;
    sectors |= (tf->lbah & 0xff) << 16;
    sectors |= (tf->lbam & 0xff) << 8;
    sectors |= (tf->lbal & 0xff);

    return sectors;
}

u64 ata_tf_to_lba(const struct ata_taskfile *tf)
{
    u64 sectors = 0;

    sectors |= (tf->device & 0x0f) << 24;
    sectors |= (tf->lbah & 0xff) << 16;
    sectors |= (tf->lbam & 0xff) << 8;
    sectors |= (tf->lbal & 0xff);

    return sectors;
}

static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
{
    unsigned int err_mask;
    struct ata_taskfile tf;
    int lba48 = ata_id_has_lba48(dev->id);

    ata_tf_init(dev, &tf);

    /* always clear all address registers */
    tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;

    if (lba48) {
        tf.command = ATA_CMD_READ_NATIVE_MAX_EXT;
        tf.flags |= ATA_TFLAG_LBA48;
    } else
        tf.command = ATA_CMD_READ_NATIVE_MAX;

    tf.protocol |= ATA_PROT_NODATA;
    tf.device |= ATA_LBA;

    err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
    if (err_mask) {
        ata_dev_warn(dev,
                 "failed to read native max address (err_mask=0x%x)\n",
                 err_mask);
        if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
            return -EACCES;
        return -EIO;
    }

    if (lba48)
        *max_sectors = ata_tf_to_lba48(&tf) + 1;
    else
        *max_sectors = ata_tf_to_lba(&tf) + 1;
    if (dev->horkage & ATA_HORKAGE_HPA_SIZE)
        (*max_sectors)--;
    return 0;
}

static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
{
    unsigned int err_mask;
    struct ata_taskfile tf;
    int lba48 = ata_id_has_lba48(dev->id);

    new_sectors--;

    ata_tf_init(dev, &tf);

    tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;

    if (lba48) {
        tf.command = ATA_CMD_SET_MAX_EXT;
        tf.flags |= ATA_TFLAG_LBA48;

        tf.hob_lbal = (new_sectors >> 24) & 0xff;
        tf.hob_lbam = (new_sectors >> 32) & 0xff;
        tf.hob_lbah = (new_sectors >> 40) & 0xff;
    } else {
        tf.command = ATA_CMD_SET_MAX;

        tf.device |= (new_sectors >> 24) & 0xf;
    }

    tf.protocol |= ATA_PROT_NODATA;
    tf.device |= ATA_LBA;

    tf.lbal = (new_sectors >> 0) & 0xff;
    tf.lbam = (new_sectors >> 8) & 0xff;
    tf.lbah = (new_sectors >> 16) & 0xff;

    err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
    if (err_mask) {
        ata_dev_warn(dev,
                 "failed to set max address (err_mask=0x%x)\n",
                 err_mask);
        if (err_mask == AC_ERR_DEV &&
            (tf.feature & (ATA_ABORTED | ATA_IDNF)))
            return -EACCES;
        return -EIO;
    }

    return 0;
}

static int ata_hpa_resize(struct ata_device *dev)
{
    struct ata_eh_context *ehc = &dev->link->eh_context;
    int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
    bool unlock_hpa = ata_ignore_hpa || dev->flags & ATA_DFLAG_UNLOCK_HPA;
    u64 sectors = ata_id_n_sectors(dev->id);
    u64 native_sectors;
    int rc;

    /* do we need to do it? */
    if (dev->class != ATA_DEV_ATA ||
        !ata_id_has_lba(dev->id) || !ata_id_hpa_enabled(dev->id) ||
        (dev->horkage & ATA_HORKAGE_BROKEN_HPA))
        return 0;

    /* read native max address */
    rc = ata_read_native_max_address(dev, &native_sectors);
    if (rc) {
        /* If device aborted the command or HPA isn't going to
         * be unlocked, skip HPA resizing.
         */
        if (rc == -EACCES || !unlock_hpa) {
            ata_dev_warn(dev,
                     "HPA support seems broken, skipping HPA handling\n");
            dev->horkage |= ATA_HORKAGE_BROKEN_HPA;

            /* we can continue if device aborted the command */
            if (rc == -EACCES)
                rc = 0;
        }

        return rc;
    }
    dev->n_native_sectors = native_sectors;

    /* nothing to do? */
    if (native_sectors <= sectors || !unlock_hpa) {
        if (!print_info || native_sectors == sectors)
            return 0;

        if (native_sectors > sectors)
            ata_dev_info(dev,
                "HPA detected: current %llu, native %llu\n",
                (unsigned long long)sectors,
                (unsigned long long)native_sectors);
        else if (native_sectors < sectors)
            ata_dev_warn(dev,
                "native sectors (%llu) is smaller than sectors (%llu)\n",
                (unsigned long long)native_sectors,
                (unsigned long long)sectors);
        return 0;
    }

    /* let's unlock HPA */
    rc = ata_set_max_sectors(dev, native_sectors);
    if (rc == -EACCES) {
        /* if device aborted the command, skip HPA resizing */
        ata_dev_warn(dev,
                 "device aborted resize (%llu -> %llu), skipping HPA handling\n",
                 (unsigned long long)sectors,
                 (unsigned long long)native_sectors);
        dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
        return 0;
    } else if (rc)
        return rc;

    /* re-read IDENTIFY data */
    rc = ata_dev_reread_id(dev, 0);
    if (rc) {
        ata_dev_err(dev,
                "failed to re-read IDENTIFY data after HPA resizing\n");
        return rc;
    }

    if (print_info) {
        u64 new_sectors = ata_id_n_sectors(dev->id);
        ata_dev_info(dev,
            "HPA unlocked: %llu -> %llu, native %llu\n",
            (unsigned long long)sectors,
            (unsigned long long)new_sectors,
            (unsigned long long)native_sectors);
    }

    return 0;
}

static inline void ata_dump_id(const u16 *id)
{
    DPRINTK("49==0x%04x  "
        "53==0x%04x  "
        "63==0x%04x  "
        "64==0x%04x  "
        "75==0x%04x  \n",
        id[49],
        id[53],
        id[63],
        id[64],
        id[75]);
    DPRINTK("80==0x%04x  "
        "81==0x%04x  "
        "82==0x%04x  "
        "83==0x%04x  "
        "84==0x%04x  \n",
        id[80],
        id[81],
        id[82],
        id[83],
        id[84]);
    DPRINTK("88==0x%04x  "
        "93==0x%04x\n",
        id[88],
        id[93]);
}

unsigned long ata_id_xfermask(const u16 *id)
{
    unsigned long pio_mask, mwdma_mask, udma_mask;

    /* Usual case. Word 53 indicates word 64 is valid */
    if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
        pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
        pio_mask <<= 3;
        pio_mask |= 0x7;
    } else {
        /* If word 64 isn't valid then Word 51 high byte holds
         * the PIO timing number for the maximum. Turn it into
         * a mask.
         */
        u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
        if (mode < 5)   /* Valid PIO range */
            pio_mask = (2 << mode) - 1;
        else
            pio_mask = 1;

        /* But wait.. there's more. Design your standards by
         * committee and you too can get a free iordy field to
         * process. However its the speeds not the modes that
         * are supported... Note drivers using the timing API
         * will get this right anyway
         */
    }

    mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;

    if (ata_id_is_cfa(id)) {
        /*
         *  Process compact flash extended modes
         */
        int pio = (id[ATA_ID_CFA_MODES] >> 0) & 0x7;
        int dma = (id[ATA_ID_CFA_MODES] >> 3) & 0x7;

        if (pio)
            pio_mask |= (1 << 5);
        if (pio > 1)
            pio_mask |= (1 << 6);
        if (dma)
            mwdma_mask |= (1 << 3);
        if (dma > 1)
            mwdma_mask |= (1 << 4);
    }

    udma_mask = 0;
    if (id[ATA_ID_FIELD_VALID] & (1 << 2))
        udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;

    return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
}

static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
{
    struct completion *waiting = qc->private_data;

    complete(waiting);
}

unsigned ata_exec_internal_sg(struct ata_device *dev,
                  struct ata_taskfile *tf, const u8 *cdb,
                  int dma_dir, struct scatterlist *sgl,
                  unsigned int n_elem, unsigned long timeout)
{
    struct ata_link *link = dev->link;
    struct ata_port *ap = link->ap;
    u8 command = tf->command;
    int auto_timeout = 0;
    struct ata_queued_cmd *qc;
    unsigned int tag, preempted_tag;
    u32 preempted_sactive, preempted_qc_active;
    int preempted_nr_active_links;
    DECLARE_COMPLETION_ONSTACK(wait);
    unsigned long flags;
    unsigned int err_mask;
    int rc;

    spin_lock_irqsave(ap->lock, flags);

    /* no internal command while frozen */
    if (ap->pflags & ATA_PFLAG_FROZEN) {
        spin_unlock_irqrestore(ap->lock, flags);
        return AC_ERR_SYSTEM;
    }

    /* initialize internal qc */

    /* XXX: Tag 0 is used for drivers with legacy EH as some
     * drivers choke if any other tag is given.  This breaks
     * ata_tag_internal() test for those drivers.  Don't use new
     * EH stuff without converting to it.
     */
    if (ap->ops->error_handler)
        tag = ATA_TAG_INTERNAL;
    else
        tag = 0;

    if (test_and_set_bit(tag, &ap->qc_allocated))
        BUG();
    qc = __ata_qc_from_tag(ap, tag);

    qc->tag = tag;
    qc->scsicmd = NULL;
    qc->ap = ap;
    qc->dev = dev;
    ata_qc_reinit(qc);

    preempted_tag = link->active_tag;
    preempted_sactive = link->sactive;
    preempted_qc_active = ap->qc_active;
    preempted_nr_active_links = ap->nr_active_links;
    link->active_tag = ATA_TAG_POISON;
    link->sactive = 0;
    ap->qc_active = 0;
    ap->nr_active_links = 0;

    /* prepare & issue qc */
    qc->tf = *tf;
    if (cdb)
        memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
    qc->flags |= ATA_QCFLAG_RESULT_TF;
    qc->dma_dir = dma_dir;
    if (dma_dir != DMA_NONE) {
        unsigned int i, buflen = 0;
        struct scatterlist *sg;

        for_each_sg(sgl, sg, n_elem, i)
            buflen += sg->length;

        ata_sg_init(qc, sgl, n_elem);
        qc->nbytes = buflen;
    }

    qc->private_data = &wait;
    qc->complete_fn = ata_qc_complete_internal;

    ata_qc_issue(qc);

    spin_unlock_irqrestore(ap->lock, flags);

    if (!timeout) {
        if (ata_probe_timeout)
            timeout = ata_probe_timeout * 1000;
        else {
            timeout = ata_internal_cmd_timeout(dev, command);
            auto_timeout = 1;
        }
    }

    if (ap->ops->error_handler)
        ata_eh_release(ap);

    rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));

    if (ap->ops->error_handler)
        ata_eh_acquire(ap);

    ata_sff_flush_pio_task(ap);

    if (!rc) {
        spin_lock_irqsave(ap->lock, flags);

        /* We're racing with irq here.  If we lose, the
         * following test prevents us from completing the qc
         * twice.  If we win, the port is frozen and will be
         * cleaned up by ->post_internal_cmd().
         */
        if (qc->flags & ATA_QCFLAG_ACTIVE) {
            qc->err_mask |= AC_ERR_TIMEOUT;

            if (ap->ops->error_handler)
                ata_port_freeze(ap);
            else
                ata_qc_complete(qc);

            if (ata_msg_warn(ap))
                ata_dev_warn(dev, "qc timeout (cmd 0x%x)\n",
                         command);
        }

        spin_unlock_irqrestore(ap->lock, flags);
    }

    /* do post_internal_cmd */
    if (ap->ops->post_internal_cmd)
        ap->ops->post_internal_cmd(qc);

    /* perform minimal error analysis */
    if (qc->flags & ATA_QCFLAG_FAILED) {
        if (qc->result_tf.command & (ATA_ERR | ATA_DF))
            qc->err_mask |= AC_ERR_DEV;

        if (!qc->err_mask)
            qc->err_mask |= AC_ERR_OTHER;

        if (qc->err_mask & ~AC_ERR_OTHER)
            qc->err_mask &= ~AC_ERR_OTHER;
    }

    /* finish up */
    spin_lock_irqsave(ap->lock, flags);

    *tf = qc->result_tf;
    err_mask = qc->err_mask;

    ata_qc_free(qc);
    link->active_tag = preempted_tag;
    link->sactive = preempted_sactive;
    ap->qc_active = preempted_qc_active;
    ap->nr_active_links = preempted_nr_active_links;

    spin_unlock_irqrestore(ap->lock, flags);

    if ((err_mask & AC_ERR_TIMEOUT) && auto_timeout)
        ata_internal_cmd_timed_out(dev, command);

    return err_mask;
}

unsigned ata_exec_internal(struct ata_device *dev,
               struct ata_taskfile *tf, const u8 *cdb,
               int dma_dir, void *buf, unsigned int buflen,
               unsigned long timeout)
{
    struct scatterlist *psg = NULL, sg;
    unsigned int n_elem = 0;

    if (dma_dir != DMA_NONE) {
        WARN_ON(!buf);
        sg_init_one(&sg, buf, buflen);
        psg = &sg;
        n_elem++;
    }

    return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
                    timeout);
}

unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
{
    struct ata_taskfile tf;

    ata_tf_init(dev, &tf);

    tf.command = cmd;
    tf.flags |= ATA_TFLAG_DEVICE;
    tf.protocol = ATA_PROT_NODATA;

    return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
}

unsigned int ata_pio_need_iordy(const struct ata_device *adev)
{
    /* Don't set IORDY if we're preparing for reset.  IORDY may
     * lead to controller lock up on certain controllers if the
     * port is not occupied.  See bko#11703 for details.
     */
    if (adev->link->ap->pflags & ATA_PFLAG_RESETTING)
        return 0;
    /* Controller doesn't support IORDY.  Probably a pointless
     * check as the caller should know this.
     */
    if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
        return 0;
    /* CF spec. r4.1 Table 22 says no iordy on PIO5 and PIO6.  */
    if (ata_id_is_cfa(adev->id)
        && (adev->pio_mode == XFER_PIO_5 || adev->pio_mode == XFER_PIO_6))
        return 0;
    /* PIO3 and higher it is mandatory */
    if (adev->pio_mode > XFER_PIO_2)
        return 1;
    /* We turn it on when possible */
    if (ata_id_has_iordy(adev->id))
        return 1;
    return 0;
}

static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
{
    /* If we have no drive specific rule, then PIO 2 is non IORDY */
    if (adev->id[ATA_ID_FIELD_VALID] & 2) { /* EIDE */
        u16 pio = adev->id[ATA_ID_EIDE_PIO];
        /* Is the speed faster than the drive allows non IORDY ? */
        if (pio) {
            /* This is cycle times not frequency - watch the logic! */
            if (pio > 240)  /* PIO2 is 240nS per cycle */
                return 3 << ATA_SHIFT_PIO;
            return 7 << ATA_SHIFT_PIO;
        }
    }
    return 3 << ATA_SHIFT_PIO;
}

unsigned int ata_do_dev_read_id(struct ata_device *dev,
                    struct ata_taskfile *tf, u16 *id)
{
    return ata_exec_internal(dev, tf, NULL, DMA_FROM_DEVICE,
                     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
}

int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
            unsigned int flags, u16 *id)
{
    struct ata_port *ap = dev->link->ap;
    unsigned int class = *p_class;
    struct ata_taskfile tf;
    unsigned int err_mask = 0;
    const char *reason;
    bool is_semb = class == ATA_DEV_SEMB;
    int may_fallback = 1, tried_spinup = 0;
    int rc;

    if (ata_msg_ctl(ap))
        ata_dev_dbg(dev, "%s: ENTER\n", __func__);

retry:
    ata_tf_init(dev, &tf);

    switch (class) {
    case ATA_DEV_SEMB:
        class = ATA_DEV_ATA;    /* some hard drives report SEMB sig */
    case ATA_DEV_ATA:
        tf.command = ATA_CMD_ID_ATA;
        break;
    case ATA_DEV_ATAPI:
        tf.command = ATA_CMD_ID_ATAPI;
        break;
    default:
        rc = -ENODEV;
        reason = "unsupported class";
        goto err_out;
    }

    tf.protocol = ATA_PROT_PIO;

    /* Some devices choke if TF registers contain garbage.  Make
     * sure those are properly initialized.
     */
    tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;

    /* Device presence detection is unreliable on some
     * controllers.  Always poll IDENTIFY if available.
     */
    tf.flags |= ATA_TFLAG_POLLING;

    if (ap->ops->read_id)
        err_mask = ap->ops->read_id(dev, &tf, id);
    else
        err_mask = ata_do_dev_read_id(dev, &tf, id);

    if (err_mask) {
        if (err_mask & AC_ERR_NODEV_HINT) {
            ata_dev_dbg(dev, "NODEV after polling detection\n");
            return -ENOENT;
        }

        if (is_semb) {
            ata_dev_info(dev,
             "IDENTIFY failed on device w/ SEMB sig, disabled\n");
            /* SEMB is not supported yet */
            *p_class = ATA_DEV_SEMB_UNSUP;
            return 0;
        }

        if ((err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) {
            /* Device or controller might have reported
             * the wrong device class.  Give a shot at the
             * other IDENTIFY if the current one is
             * aborted by the device.
             */
            if (may_fallback) {
                may_fallback = 0;

                if (class == ATA_DEV_ATA)
                    class = ATA_DEV_ATAPI;
                else
                    class = ATA_DEV_ATA;
                goto retry;
            }

            /* Control reaches here iff the device aborted
             * both flavors of IDENTIFYs which happens
             * sometimes with phantom devices.
             */
            ata_dev_dbg(dev,
                    "both IDENTIFYs aborted, assuming NODEV\n");
            return -ENOENT;
        }

        rc = -EIO;
        reason = "I/O error";
        goto err_out;
    }

    if (dev->horkage & ATA_HORKAGE_DUMP_ID) {
        ata_dev_dbg(dev, "dumping IDENTIFY data, "
                "class=%d may_fallback=%d tried_spinup=%d\n",
                class, may_fallback, tried_spinup);
        print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,
                   16, 2, id, ATA_ID_WORDS * sizeof(*id), true);
    }

    /* Falling back doesn't make sense if ID data was read
     * successfully at least once.
     */
    may_fallback = 0;

    swap_buf_le16(id, ATA_ID_WORDS);

    /* sanity check */
    rc = -EINVAL;
    reason = "device reports invalid type";

    if (class == ATA_DEV_ATA) {
        if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
            goto err_out;
        if (ap->host->flags & ATA_HOST_IGNORE_ATA &&
                            ata_id_is_ata(id)) {
            ata_dev_dbg(dev,
                "host indicates ignore ATA devices, ignored\n");
            return -ENOENT;
        }
    } else {
        if (ata_id_is_ata(id))
            goto err_out;
    }

    if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
        tried_spinup = 1;
        /*
         * Drive powered-up in standby mode, and requires a specific
         * SET_FEATURES spin-up subcommand before it will accept
         * anything other than the original IDENTIFY command.
         */
        err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
        if (err_mask && id[2] != 0x738c) {
            rc = -EIO;
            reason = "SPINUP failed";
            goto err_out;
        }
        /*
         * If the drive initially returned incomplete IDENTIFY info,
         * we now must reissue the IDENTIFY command.
         */
        if (id[2] == 0x37c8)
            goto retry;
    }

    if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
        /*
         * The exact sequence expected by certain pre-ATA4 drives is:
         * SRST RESET
         * IDENTIFY (optional in early ATA)
         * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
         * anything else..
         * Some drives were very specific about that exact sequence.
         *
         * Note that ATA4 says lba is mandatory so the second check
         * should never trigger.
         */
        if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
            err_mask = ata_dev_init_params(dev, id[3], id[6]);
            if (err_mask) {
                rc = -EIO;
                reason = "INIT_DEV_PARAMS failed";
                goto err_out;
            }

            /* current CHS translation info (id[53-58]) might be
             * changed. reread the identify device info.
             */
            flags &= ~ATA_READID_POSTRESET;
            goto retry;
        }
    }

    *p_class = class;

    return 0;

 err_out:
    if (ata_msg_warn(ap))
        ata_dev_warn(dev, "failed to IDENTIFY (%s, err_mask=0x%x)\n",
                 reason, err_mask);
    return rc;
}

static int ata_do_link_spd_horkage(struct ata_device *dev)
{
    struct ata_link *plink = ata_dev_phys_link(dev);
    u32 target, target_limit;

    if (!sata_scr_valid(plink))
        return 0;

    if (dev->horkage & ATA_HORKAGE_1_5_GBPS)
        target = 1;
    else
        return 0;

    target_limit = (1 << target) - 1;

    /* if already on stricter limit, no need to push further */
    if (plink->sata_spd_limit <= target_limit)
        return 0;

    plink->sata_spd_limit = target_limit;

    /* Request another EH round by returning -EAGAIN if link is
     * going faster than the target speed.  Forward progress is
     * guaranteed by setting sata_spd_limit to target_limit above.
     */
    if (plink->sata_spd > target) {
        ata_dev_info(dev, "applying link speed limit horkage to %s\n",
                 sata_spd_string(target));
        return -EAGAIN;
    }
    return 0;
}

static inline u8 ata_dev_knobble(struct ata_device *dev)
{
    struct ata_port *ap = dev->link->ap;

    if (ata_dev_blacklisted(dev) & ATA_HORKAGE_BRIDGE_OK)
        return 0;

    return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
}

static int ata_dev_config_ncq(struct ata_device *dev,
                   char *desc, size_t desc_sz)
{
    struct ata_port *ap = dev->link->ap;
    int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
    unsigned int err_mask;
    char *aa_desc = "";

    if (!ata_id_has_ncq(dev->id)) {
        desc[0] = '\0';
        return 0;
    }
    if (dev->horkage & ATA_HORKAGE_NONCQ) {
        snprintf(desc, desc_sz, "NCQ (not used)");
        return 0;
    }
    if (ap->flags & ATA_FLAG_NCQ) {
        hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
        dev->flags |= ATA_DFLAG_NCQ;
    }

    if (!(dev->horkage & ATA_HORKAGE_BROKEN_FPDMA_AA) &&
        (ap->flags & ATA_FLAG_FPDMA_AA) &&
        ata_id_has_fpdma_aa(dev->id)) {
        err_mask = ata_dev_set_feature(dev, SETFEATURES_SATA_ENABLE,
            SATA_FPDMA_AA);
        if (err_mask) {
            ata_dev_err(dev,
                    "failed to enable AA (error_mask=0x%x)\n",
                    err_mask);
            if (err_mask != AC_ERR_DEV) {
                dev->horkage |= ATA_HORKAGE_BROKEN_FPDMA_AA;
                return -EIO;
            }
        } else
            aa_desc = ", AA";
    }

    if (hdepth >= ddepth)
        snprintf(desc, desc_sz, "NCQ (depth %d)%s", ddepth, aa_desc);
    else
        snprintf(desc, desc_sz, "NCQ (depth %d/%d)%s", hdepth,
            ddepth, aa_desc);
    return 0;
}

int ata_dev_configure(struct ata_device *dev)
{
    struct ata_port *ap = dev->link->ap;
    struct ata_eh_context *ehc = &dev->link->eh_context;
    int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
    const u16 *id = dev->id;
    unsigned long xfer_mask;
    unsigned int err_mask;
    char revbuf[7];     /* XYZ-99\0 */
    char fwrevbuf[ATA_ID_FW_REV_LEN+1];
    char modelbuf[ATA_ID_PROD_LEN+1];
    int rc;

    if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
        ata_dev_info(dev, "%s: ENTER/EXIT -- nodev\n", __func__);
        return 0;
    }

    if (ata_msg_probe(ap))
        ata_dev_dbg(dev, "%s: ENTER\n", __func__);

    /* set horkage */
    dev->horkage |= ata_dev_blacklisted(dev);
    ata_force_horkage(dev);

    if (dev->horkage & ATA_HORKAGE_DISABLE) {
        ata_dev_info(dev, "unsupported device, disabling\n");
        ata_dev_disable(dev);
        return 0;
    }

    if ((!atapi_enabled || (ap->flags & ATA_FLAG_NO_ATAPI)) &&
        dev->class == ATA_DEV_ATAPI) {
        ata_dev_warn(dev, "WARNING: ATAPI is %s, device ignored\n",
                 atapi_enabled ? "not supported with this driver"
                 : "disabled");
        ata_dev_disable(dev);
        return 0;
    }

    rc = ata_do_link_spd_horkage(dev);
    if (rc)
        return rc;

    /* let ACPI work its magic */
    rc = ata_acpi_on_devcfg(dev);
    if (rc)
        return rc;

    /* massage HPA, do it early as it might change IDENTIFY data */
    rc = ata_hpa_resize(dev);
    if (rc)
        return rc;

    /* print device capabilities */
    if (ata_msg_probe(ap))
        ata_dev_dbg(dev,
                "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
                "85:%04x 86:%04x 87:%04x 88:%04x\n",
                __func__,
                id[49], id[82], id[83], id[84],
                id[85], id[86], id[87], id[88]);

    /* initialize to-be-configured parameters */
    dev->flags &= ~ATA_DFLAG_CFG_MASK;
    dev->max_sectors = 0;
    dev->cdb_len = 0;
    dev->n_sectors = 0;
    dev->cylinders = 0;
    dev->heads = 0;
    dev->sectors = 0;
    dev->multi_count = 0;

    /*
     * common ATA, ATAPI feature tests
     */

    /* find max transfer mode; for printk only */
    xfer_mask = ata_id_xfermask(id);

    if (ata_msg_probe(ap))
        ata_dump_id(id);

    /* SCSI only uses 4-char revisions, dump full 8 chars from ATA */
    ata_id_c_string(dev->id, fwrevbuf, ATA_ID_FW_REV,
            sizeof(fwrevbuf));

    ata_id_c_string(dev->id, modelbuf, ATA_ID_PROD,
            sizeof(modelbuf));

    /* ATA-specific feature tests */
    if (dev->class == ATA_DEV_ATA) {
        if (ata_id_is_cfa(id)) {
            /* CPRM may make this media unusable */
            if (id[ATA_ID_CFA_KEY_MGMT] & 1)
                ata_dev_warn(dev,
    "supports DRM functions and may not be fully accessible\n");
            snprintf(revbuf, 7, "CFA");
        } else {
            snprintf(revbuf, 7, "ATA-%d", ata_id_major_version(id));
            /* Warn the user if the device has TPM extensions */
            if (ata_id_has_tpm(id))
                ata_dev_warn(dev,
    "supports DRM functions and may not be fully accessible\n");
        }

        dev->n_sectors = ata_id_n_sectors(id);

        /* get current R/W Multiple count setting */
        if ((dev->id[47] >> 8) == 0x80 && (dev->id[59] & 0x100)) {
            unsigned int max = dev->id[47] & 0xff;
            unsigned int cnt = dev->id[59] & 0xff;
            /* only recognize/allow powers of two here */
            if (is_power_of_2(max) && is_power_of_2(cnt))
                if (cnt <= max)
                    dev->multi_count = cnt;
        }

        if (ata_id_has_lba(id)) {
            const char *lba_desc;
            char ncq_desc[24];

            lba_desc = "LBA";
            dev->flags |= ATA_DFLAG_LBA;
            if (ata_id_has_lba48(id)) {
                dev->flags |= ATA_DFLAG_LBA48;
                lba_desc = "LBA48";

                if (dev->n_sectors >= (1UL << 28) &&
                    ata_id_has_flush_ext(id))
                    dev->flags |= ATA_DFLAG_FLUSH_EXT;
            }

            /* config NCQ */
            rc = ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
            if (rc)
                return rc;

            /* print device info to dmesg */
            if (ata_msg_drv(ap) && print_info) {
                ata_dev_info(dev, "%s: %s, %s, max %s\n",
                         revbuf, modelbuf, fwrevbuf,
                         ata_mode_string(xfer_mask));
                ata_dev_info(dev,
                         "%llu sectors, multi %u: %s %s\n",
                    (unsigned long long)dev->n_sectors,
                    dev->multi_count, lba_desc, ncq_desc);
            }
        } else {
            /* CHS */

            /* Default translation */
            dev->cylinders  = id[1];
            dev->heads  = id[3];
            dev->sectors    = id[6];

            if (ata_id_current_chs_valid(id)) {
                /* Current CHS translation is valid. */
                dev->cylinders = id[54];
                dev->heads     = id[55];
                dev->sectors   = id[56];
            }

            /* print device info to dmesg */
            if (ata_msg_drv(ap) && print_info) {
                ata_dev_info(dev, "%s: %s, %s, max %s\n",
                         revbuf,    modelbuf, fwrevbuf,
                         ata_mode_string(xfer_mask));
                ata_dev_info(dev,
                         "%llu sectors, multi %u, CHS %u/%u/%u\n",
                         (unsigned long long)dev->n_sectors,
                         dev->multi_count, dev->cylinders,
                         dev->heads, dev->sectors);
            }
        }

        /* check and mark DevSlp capability */
        if (ata_id_has_devslp(dev->id))
            dev->flags |= ATA_DFLAG_DEVSLP;

        /* Obtain SATA Settings page from Identify Device Data Log,
         * which contains DevSlp timing variables etc.
         * Exclude old devices with ata_id_has_ncq()
         */
        if (ata_id_has_ncq(dev->id)) {
            err_mask = ata_read_log_page(dev,
                             ATA_LOG_SATA_ID_DEV_DATA,
                             ATA_LOG_SATA_SETTINGS,
                             dev->sata_settings,
                             1);
            if (err_mask)
                ata_dev_dbg(dev,
                        "failed to get Identify Device Data, Emask 0x%x\n",
                        err_mask);
        }

        dev->cdb_len = 16;
    }

    /* ATAPI-specific feature tests */
    else if (dev->class == ATA_DEV_ATAPI) {
        const char *cdb_intr_string = "";
        const char *atapi_an_string = "";
        const char *dma_dir_string = "";
        u32 sntf;

        rc = atapi_cdb_len(id);
        if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
            if (ata_msg_warn(ap))
                ata_dev_warn(dev, "unsupported CDB len\n");
            rc = -EINVAL;
            goto err_out_nosup;
        }
        dev->cdb_len = (unsigned int) rc;

        /* Enable ATAPI AN if both the host and device have
         * the support.  If PMP is attached, SNTF is required
         * to enable ATAPI AN to discern between PHY status
         * changed notifications and ATAPI ANs.
         */
        if (atapi_an &&
            (ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
            (!sata_pmp_attached(ap) ||
             sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
            /* issue SET feature command to turn this on */
            err_mask = ata_dev_set_feature(dev,
                    SETFEATURES_SATA_ENABLE, SATA_AN);
            if (err_mask)
                ata_dev_err(dev,
                        "failed to enable ATAPI AN (err_mask=0x%x)\n",
                        err_mask);
            else {
                dev->flags |= ATA_DFLAG_AN;
                atapi_an_string = ", ATAPI AN";
            }
        }

        if (ata_id_cdb_intr(dev->id)) {
            dev->flags |= ATA_DFLAG_CDB_INTR;
            cdb_intr_string = ", CDB intr";
        }

        if (atapi_dmadir || atapi_id_dmadir(dev->id)) {
            dev->flags |= ATA_DFLAG_DMADIR;
            dma_dir_string = ", DMADIR";
        }

        if (ata_id_has_da(dev->id))
            dev->flags |= ATA_DFLAG_DA;

        /* print device info to dmesg */
        if (ata_msg_drv(ap) && print_info)
            ata_dev_info(dev,
                     "ATAPI: %s, %s, max %s%s%s%s\n",
                     modelbuf, fwrevbuf,
                     ata_mode_string(xfer_mask),
                     cdb_intr_string, atapi_an_string,
                     dma_dir_string);
    }

    /* determine max_sectors */
    dev->max_sectors = ATA_MAX_SECTORS;
    if (dev->flags & ATA_DFLAG_LBA48)
        dev->max_sectors = ATA_MAX_SECTORS_LBA48;

    /* Limit PATA drive on SATA cable bridge transfers to udma5,
       200 sectors */
    if (ata_dev_knobble(dev)) {
        if (ata_msg_drv(ap) && print_info)
            ata_dev_info(dev, "applying bridge limits\n");
        dev->udma_mask &= ATA_UDMA5;
        dev->max_sectors = ATA_MAX_SECTORS;
    }

    if ((dev->class == ATA_DEV_ATAPI) &&
        (atapi_command_packet_set(id) == TYPE_TAPE)) {
        dev->max_sectors = ATA_MAX_SECTORS_TAPE;
        dev->horkage |= ATA_HORKAGE_STUCK_ERR;
    }

    if (dev->horkage & ATA_HORKAGE_MAX_SEC_128)
        dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
                     dev->max_sectors);

    if (ap->ops->dev_config)
        ap->ops->dev_config(dev);

    if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
        /* Let the user know. We don't want to disallow opens for
           rescue purposes, or in case the vendor is just a blithering
           idiot. Do this after the dev_config call as some controllers
           with buggy firmware may want to avoid reporting false device
           bugs */

        if (print_info) {
            ata_dev_warn(dev,
"Drive reports diagnostics failure. This may indicate a drive\n");
            ata_dev_warn(dev,
"fault or invalid emulation. Contact drive vendor for information.\n");
        }
    }

    if ((dev->horkage & ATA_HORKAGE_FIRMWARE_WARN) && print_info) {
        ata_dev_warn(dev, "WARNING: device requires firmware update to be fully functional\n");
        ata_dev_warn(dev, "         contact the vendor or visit http://ata.wiki.kernel.org\n");
    }

    return 0;

err_out_nosup:
    if (ata_msg_probe(ap))
        ata_dev_dbg(dev, "%s: EXIT, err\n", __func__);
    return rc;
}

int ata_cable_40wire(struct ata_port *ap)
{
    return ATA_CBL_PATA40;
}

int ata_cable_80wire(struct ata_port *ap)
{
    return ATA_CBL_PATA80;
}

int ata_cable_unknown(struct ata_port *ap)
{
    return ATA_CBL_PATA_UNK;
}

int ata_cable_ignore(struct ata_port *ap)
{
    return ATA_CBL_PATA_IGN;
}

int ata_cable_sata(struct ata_port *ap)
{
    return ATA_CBL_SATA;
}

int ata_bus_probe(struct ata_port *ap)
{
    unsigned int classes[ATA_MAX_DEVICES];
    int tries[ATA_MAX_DEVICES];
    int rc;
    struct ata_device *dev;

    ata_for_each_dev(dev, &ap->link, ALL)
        tries[dev->devno] = ATA_PROBE_MAX_TRIES;

 retry:
    ata_for_each_dev(dev, &ap->link, ALL) {
        /* If we issue an SRST then an ATA drive (not ATAPI)
         * may change configuration and be in PIO0 timing. If
         * we do a hard reset (or are coming from power on)
         * this is true for ATA or ATAPI. Until we've set a
         * suitable controller mode we should not touch the
         * bus as we may be talking too fast.
         */
        dev->pio_mode = XFER_PIO_0;

        /* If the controller has a pio mode setup function
         * then use it to set the chipset to rights. Don't
         * touch the DMA setup as that will be dealt with when
         * configuring devices.
         */
        if (ap->ops->set_piomode)
            ap->ops->set_piomode(ap, dev);
    }

    /* reset and determine device classes */
    ap->ops->phy_reset(ap);

    ata_for_each_dev(dev, &ap->link, ALL) {
        if (dev->class != ATA_DEV_UNKNOWN)
            classes[dev->devno] = dev->class;
        else
            classes[dev->devno] = ATA_DEV_NONE;

        dev->class = ATA_DEV_UNKNOWN;
    }

    /* read IDENTIFY page and configure devices. We have to do the identify
       specific sequence bass-ackwards so that PDIAG- is released by
       the slave device */

    ata_for_each_dev(dev, &ap->link, ALL_REVERSE) {
        if (tries[dev->devno])
            dev->class = classes[dev->devno];

        if (!ata_dev_enabled(dev))
            continue;

        rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
                     dev->id);
        if (rc)
            goto fail;
    }

    /* Now ask for the cable type as PDIAG- should have been released */
    if (ap->ops->cable_detect)
        ap->cbl = ap->ops->cable_detect(ap);

    /* We may have SATA bridge glue hiding here irrespective of
     * the reported cable types and sensed types.  When SATA
     * drives indicate we have a bridge, we don't know which end
     * of the link the bridge is which is a problem.
     */
    ata_for_each_dev(dev, &ap->link, ENABLED)
        if (ata_id_is_sata(dev->id))
            ap->cbl = ATA_CBL_SATA;

    /* After the identify sequence we can now set up the devices. We do
       this in the normal order so that the user doesn't get confused */

    ata_for_each_dev(dev, &ap->link, ENABLED) {
        ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
        rc = ata_dev_configure(dev);
        ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
        if (rc)
            goto fail;
    }

    /* configure transfer mode */
    rc = ata_set_mode(&ap->link, &dev);
    if (rc)
        goto fail;

    ata_for_each_dev(dev, &ap->link, ENABLED)
        return 0;

    return -ENODEV;

 fail:
    tries[dev->devno]--;

    switch (rc) {
    case -EINVAL:
        /* eeek, something went very wrong, give up */
        tries[dev->devno] = 0;
        break;

    case -ENODEV:
        /* give it just one more chance */
        tries[dev->devno] = min(tries[dev->devno], 1);
    case -EIO:
        if (tries[dev->devno] == 1) {
            /* This is the last chance, better to slow
             * down than lose it.
             */
            sata_down_spd_limit(&ap->link, 0);
            ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
        }
    }

    if (!tries[dev->devno])
        ata_dev_disable(dev);

    goto retry;
}

static void sata_print_link_status(struct ata_link *link)
{
    u32 sstatus, scontrol, tmp;

    if (sata_scr_read(link, SCR_STATUS, &sstatus))
        return;
    sata_scr_read(link, SCR_CONTROL, &scontrol);

    if (ata_phys_link_online(link)) {
        tmp = (sstatus >> 4) & 0xf;
        ata_link_info(link, "SATA link up %s (SStatus %X SControl %X)\n",
                  sata_spd_string(tmp), sstatus, scontrol);
    } else {
        ata_link_info(link, "SATA link down (SStatus %X SControl %X)\n",
                  sstatus, scontrol);
    }
}

struct ata_device *ata_dev_pair(struct ata_device *adev)
{
    struct ata_link *link = adev->link;
    struct ata_device *pair = &link->device[1 - adev->devno];
    if (!ata_dev_enabled(pair))
        return NULL;
    return pair;
}

int sata_down_spd_limit(struct ata_link *link, u32 spd_limit)
{
    u32 sstatus, spd, mask;
    int rc, bit;

    if (!sata_scr_valid(link))
        return -EOPNOTSUPP;

    /* If SCR can be read, use it to determine the current SPD.
     * If not, use cached value in link->sata_spd.
     */
    rc = sata_scr_read(link, SCR_STATUS, &sstatus);
    if (rc == 0 && ata_sstatus_online(sstatus))
        spd = (sstatus >> 4) & 0xf;
    else
        spd = link->sata_spd;

    mask = link->sata_spd_limit;
    if (mask <= 1)
        return -EINVAL;

    /* unconditionally mask off the highest bit */
    bit = fls(mask) - 1;
    mask &= ~(1 << bit);

    /* Mask off all speeds higher than or equal to the current
     * one.  Force 1.5Gbps if current SPD is not available.
     */
    if (spd > 1)
        mask &= (1 << (spd - 1)) - 1;
    else
        mask &= 1;

    /* were we already at the bottom? */
    if (!mask)
        return -EINVAL;

    if (spd_limit) {
        if (mask & ((1 << spd_limit) - 1))
            mask &= (1 << spd_limit) - 1;
        else {
            bit = ffs(mask) - 1;
            mask = 1 << bit;
        }
    }

    link->sata_spd_limit = mask;

    ata_link_warn(link, "limiting SATA link speed to %s\n",
              sata_spd_string(fls(mask)));

    return 0;
}

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;
}

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);
}

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;
}

/*
 * This mode timing computation functionality is ported over from
 * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
 */
/*
 * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
 * These were taken from ATA/ATAPI-6 standard, rev 0a, except
 * for UDMA6, which is currently supported only by Maxtor drives.
 *
 * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
 */

static const struct ata_timing ata_timing[] = {
/*  { XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 0,  960,   0 }, */
    { XFER_PIO_0,     70, 290, 240, 600, 165, 150, 0,  600,   0 },
    { XFER_PIO_1,     50, 290,  93, 383, 125, 100, 0,  383,   0 },
    { XFER_PIO_2,     30, 290,  40, 330, 100,  90, 0,  240,   0 },
    { XFER_PIO_3,     30,  80,  70, 180,  80,  70, 0,  180,   0 },
    { XFER_PIO_4,     25,  70,  25, 120,  70,  25, 0,  120,   0 },
    { XFER_PIO_5,     15,  65,  25, 100,  65,  25, 0,  100,   0 },
    { XFER_PIO_6,     10,  55,  20,  80,  55,  20, 0,   80,   0 },

    { XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 50, 960,   0 },
    { XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 30, 480,   0 },
    { XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 20, 240,   0 },

    { XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 20, 480,   0 },
    { XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 5,  150,   0 },
    { XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 5,  120,   0 },
    { XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 5,  100,   0 },
    { XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20, 5,   80,   0 },

/*  { XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0, 0,    0, 150 }, */
    { XFER_UDMA_0,     0,   0,   0,   0,   0,   0, 0,    0, 120 },
    { XFER_UDMA_1,     0,   0,   0,   0,   0,   0, 0,    0,  80 },
    { XFER_UDMA_2,     0,   0,   0,   0,   0,   0, 0,    0,  60 },
    { XFER_UDMA_3,     0,   0,   0,   0,   0,   0, 0,    0,  45 },
    { XFER_UDMA_4,     0,   0,   0,   0,   0,   0, 0,    0,  30 },
    { XFER_UDMA_5,     0,   0,   0,   0,   0,   0, 0,    0,  20 },
    { XFER_UDMA_6,     0,   0,   0,   0,   0,   0, 0,    0,  15 },

    { 0xFF }
};

#define ENOUGH(v, unit)     (((v)-1)/(unit)+1)
#define EZ(v, unit)     ((v)?ENOUGH(v, unit):0)

static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
{
    q->setup    = EZ(t->setup      * 1000,  T);
    q->act8b    = EZ(t->act8b      * 1000,  T);
    q->rec8b    = EZ(t->rec8b      * 1000,  T);
    q->cyc8b    = EZ(t->cyc8b      * 1000,  T);
    q->active   = EZ(t->active     * 1000,  T);
    q->recover  = EZ(t->recover    * 1000,  T);
    q->dmack_hold   = EZ(t->dmack_hold * 1000,  T);
    q->cycle    = EZ(t->cycle      * 1000,  T);
    q->udma     = EZ(t->udma       * 1000, UT);
}

void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
              struct ata_timing *m, unsigned int what)
{
    if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
    if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
    if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
    if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
    if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
    if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
    if (what & ATA_TIMING_DMACK_HOLD) m->dmack_hold = max(a->dmack_hold, b->dmack_hold);
    if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
    if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
}

const struct ata_timing *ata_timing_find_mode(u8 xfer_mode)
{
    const struct ata_timing *t = ata_timing;

    while (xfer_mode > t->mode)
        t++;

    if (xfer_mode == t->mode)
        return t;

    WARN_ONCE(true, "%s: unable to find timing for xfer_mode 0x%x\n",
            __func__, xfer_mode);

    return NULL;
}

int ata_timing_compute(struct ata_device *adev, unsigned short speed,
               struct ata_timing *t, int T, int UT)
{
    const u16 *id = adev->id;
    const struct ata_timing *s;
    struct ata_timing p;

    /*
     * Find the mode.
     */

    if (!(s = ata_timing_find_mode(speed)))
        return -EINVAL;

    memcpy(t, s, sizeof(*s));

    /*
     * If the drive is an EIDE drive, it can tell us it needs extended
     * PIO/MW_DMA cycle timing.
     */

    if (id[ATA_ID_FIELD_VALID] & 2) {   /* EIDE drive */
        memset(&p, 0, sizeof(p));

        if (speed >= XFER_PIO_0 && speed < XFER_SW_DMA_0) {
            if (speed <= XFER_PIO_2)
                p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO];
            else if ((speed <= XFER_PIO_4) ||
                 (speed == XFER_PIO_5 && !ata_id_is_cfa(id)))
                p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO_IORDY];
        } else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2)
            p.cycle = id[ATA_ID_EIDE_DMA_MIN];

        ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
    }

    /*
     * Convert the timing to bus clock counts.
     */

    ata_timing_quantize(t, t, T, UT);

    /*
     * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
     * S.M.A.R.T * and some other commands. We have to ensure that the
     * DMA cycle timing is slower/equal than the fastest PIO timing.
     */

    if (speed > XFER_PIO_6) {
        ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
        ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
    }

    /*
     * Lengthen active & recovery time so that cycle time is correct.
     */

    if (t->act8b + t->rec8b < t->cyc8b) {
        t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
        t->rec8b = t->cyc8b - t->act8b;
    }

    if (t->active + t->recover < t->cycle) {
        t->active += (t->cycle - (t->active + t->recover)) / 2;
        t->recover = t->cycle - t->active;
    }

    /* In a few cases quantisation may produce enough errors to
       leave t->cycle too low for the sum of active and recovery
       if so we must correct this */
    if (t->active + t->recover > t->cycle)
        t->cycle = t->active + t->recover;

    return 0;
}

u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle)
{
    u8 base_mode = 0xff, last_mode = 0xff;
    const struct ata_xfer_ent *ent;
    const struct ata_timing *t;

    for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
        if (ent->shift == xfer_shift)
            base_mode = ent->base;

    for (t = ata_timing_find_mode(base_mode);
         t && ata_xfer_mode2shift(t->mode) == xfer_shift; t++) {
        unsigned short this_cycle;

        switch (xfer_shift) {
        case ATA_SHIFT_PIO:
        case ATA_SHIFT_MWDMA:
            this_cycle = t->cycle;
            break;
        case ATA_SHIFT_UDMA:
            this_cycle = t->udma;
            break;
        default:
            return 0xff;
        }

        if (cycle > this_cycle)
            break;

        last_mode = t->mode;
    }

    return last_mode;
}

int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
{
    char buf[32];
    unsigned long orig_mask, xfer_mask;
    unsigned long pio_mask, mwdma_mask, udma_mask;
    int quiet, highbit;

    quiet = !!(sel & ATA_DNXFER_QUIET);
    sel &= ~ATA_DNXFER_QUIET;

    xfer_mask = orig_mask = ata_pack_xfermask(dev->pio_mask,
                          dev->mwdma_mask,
                          dev->udma_mask);
    ata_unpack_xfermask(xfer_mask, &pio_mask, &mwdma_mask, &udma_mask);

    switch (sel) {
    case ATA_DNXFER_PIO:
        highbit = fls(pio_mask) - 1;
        pio_mask &= ~(1 << highbit);
        break;

    case ATA_DNXFER_DMA:
        if (udma_mask) {
            highbit = fls(udma_mask) - 1;
            udma_mask &= ~(1 << highbit);
            if (!udma_mask)
                return -ENOENT;
        } else if (mwdma_mask) {
            highbit = fls(mwdma_mask) - 1;
            mwdma_mask &= ~(1 << highbit);
            if (!mwdma_mask)
                return -ENOENT;
        }
        break;

    case ATA_DNXFER_40C:
        udma_mask &= ATA_UDMA_MASK_40C;
        break;

    case ATA_DNXFER_FORCE_PIO0:
        pio_mask &= 1;
    case ATA_DNXFER_FORCE_PIO:
        mwdma_mask = 0;
        udma_mask = 0;
        break;

    default:
        BUG();
    }

    xfer_mask &= ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);

    if (!(xfer_mask & ATA_MASK_PIO) || xfer_mask == orig_mask)
        return -ENOENT;

    if (!quiet) {
        if (xfer_mask & (ATA_MASK_MWDMA | ATA_MASK_UDMA))
            snprintf(buf, sizeof(buf), "%s:%s",
                 ata_mode_string(xfer_mask),
                 ata_mode_string(xfer_mask & ATA_MASK_PIO));
        else
            snprintf(buf, sizeof(buf), "%s",
                 ata_mode_string(xfer_mask));

        ata_dev_warn(dev, "limiting speed to %s\n", buf);
    }

    ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
                &dev->udma_mask);

    return 0;
}

static int ata_dev_set_mode(struct ata_device *dev)
{
    struct ata_port *ap = dev->link->ap;
    struct ata_eh_context *ehc = &dev->link->eh_context;
    const bool nosetxfer = dev->horkage & ATA_HORKAGE_NOSETXFER;
    const char *dev_err_whine = "";
    int ign_dev_err = 0;
    unsigned int err_mask = 0;
    int rc;

    dev->flags &= ~ATA_DFLAG_PIO;
    if (dev->xfer_shift == ATA_SHIFT_PIO)
        dev->flags |= ATA_DFLAG_PIO;

    if (nosetxfer && ap->flags & ATA_FLAG_SATA && ata_id_is_sata(dev->id))
        dev_err_whine = " (SET_XFERMODE skipped)";
    else {
        if (nosetxfer)
            ata_dev_warn(dev,
                     "NOSETXFER but PATA detected - can't "
                     "skip SETXFER, might malfunction\n");
        err_mask = ata_dev_set_xfermode(dev);
    }

    if (err_mask & ~AC_ERR_DEV)
        goto fail;

    /* revalidate */
    ehc->i.flags |= ATA_EHI_POST_SETMODE;
    rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
    ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
    if (rc)
        return rc;

    if (dev->xfer_shift == ATA_SHIFT_PIO) {
        /* Old CFA may refuse this command, which is just fine */
        if (ata_id_is_cfa(dev->id))
            ign_dev_err = 1;
        /* Catch several broken garbage emulations plus some pre
           ATA devices */
        if (ata_id_major_version(dev->id) == 0 &&
                    dev->pio_mode <= XFER_PIO_2)
            ign_dev_err = 1;
        /* Some very old devices and some bad newer ones fail
           any kind of SET_XFERMODE request but support PIO0-2
           timings and no IORDY */
        if (!ata_id_has_iordy(dev->id) && dev->pio_mode <= XFER_PIO_2)
            ign_dev_err = 1;
    }
    /* Early MWDMA devices do DMA but don't allow DMA mode setting.
       Don't fail an MWDMA0 set IFF the device indicates it is in MWDMA0 */
    if (dev->xfer_shift == ATA_SHIFT_MWDMA &&
        dev->dma_mode == XFER_MW_DMA_0 &&
        (dev->id[63] >> 8) & 1)
        ign_dev_err = 1;

    /* if the device is actually configured correctly, ignore dev err */
    if (dev->xfer_mode == ata_xfer_mask2mode(ata_id_xfermask(dev->id)))
        ign_dev_err = 1;

    if (err_mask & AC_ERR_DEV) {
        if (!ign_dev_err)
            goto fail;
        else
            dev_err_whine = " (device error ignored)";
    }

    DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
        dev->xfer_shift, (int)dev->xfer_mode);

    ata_dev_info(dev, "configured for %s%s\n",
             ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)),
             dev_err_whine);

    return 0;

 fail:
    ata_dev_err(dev, "failed to set xfermode (err_mask=0x%x)\n", err_mask);
    return -EIO;
}

int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
{
    struct ata_port *ap = link->ap;
    struct ata_device *dev;
    int rc = 0, used_dma = 0, found = 0;

    /* step 1: calculate xfer_mask */
    ata_for_each_dev(dev, link, ENABLED) {
        unsigned long pio_mask, dma_mask;
        unsigned int mode_mask;

        mode_mask = ATA_DMA_MASK_ATA;
        if (dev->class == ATA_DEV_ATAPI)
            mode_mask = ATA_DMA_MASK_ATAPI;
        else if (ata_id_is_cfa(dev->id))
            mode_mask = ATA_DMA_MASK_CFA;

        ata_dev_xfermask(dev);
        ata_force_xfermask(dev);

        pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);

        if (libata_dma_mask & mode_mask)
            dma_mask = ata_pack_xfermask(0, dev->mwdma_mask,
                             dev->udma_mask);
        else
            dma_mask = 0;

        dev->pio_mode = ata_xfer_mask2mode(pio_mask);
        dev->dma_mode = ata_xfer_mask2mode(dma_mask);

        found = 1;
        if (ata_dma_enabled(dev))
            used_dma = 1;
    }
    if (!found)
        goto out;

    /* step 2: always set host PIO timings */
    ata_for_each_dev(dev, link, ENABLED) {
        if (dev->pio_mode == 0xff) {
            ata_dev_warn(dev, "no PIO support\n");
            rc = -EINVAL;
            goto out;
        }

        dev->xfer_mode = dev->pio_mode;
        dev->xfer_shift = ATA_SHIFT_PIO;
        if (ap->ops->set_piomode)
            ap->ops->set_piomode(ap, dev);
    }

    /* step 3: set host DMA timings */
    ata_for_each_dev(dev, link, ENABLED) {
        if (!ata_dma_enabled(dev))
            continue;

        dev->xfer_mode = dev->dma_mode;
        dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
        if (ap->ops->set_dmamode)
            ap->ops->set_dmamode(ap, dev);
    }

    /* step 4: update devices' xfer mode */
    ata_for_each_dev(dev, link, ENABLED) {
        rc = ata_dev_set_mode(dev);
        if (rc)
            goto out;
    }

    /* Record simplex status. If we selected DMA then the other
     * host channels are not permitted to do so.
     */
    if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
        ap->host->simplex_claimed = ap;

 out:
    if (rc)
        *r_failed_dev = dev;
    return rc;
}

int ata_wait_ready(struct ata_link *link, unsigned long deadline,
           int (*check_ready)(struct ata_link *link))
{
    unsigned long start = jiffies;
    unsigned long nodev_deadline;
    int warned = 0;

    /* choose which 0xff timeout to use, read comment in libata.h */
    if (link->ap->host->flags & ATA_HOST_PARALLEL_SCAN)
        nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT_LONG);
    else
        nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT);

    /* Slave readiness can't be tested separately from master.  On
     * M/S emulation configuration, this function should be called
     * only on the master and it will handle both master and slave.
     */
    WARN_ON(link == link->ap->slave_link);

    if (time_after(nodev_deadline, deadline))
        nodev_deadline = deadline;

    while (1) {
        unsigned long now = jiffies;
        int ready, tmp;

        ready = tmp = check_ready(link);
        if (ready > 0)
            return 0;

        /*
         * -ENODEV could be transient.  Ignore -ENODEV if link
         * is online.  Also, some SATA devices take a long
         * time to clear 0xff after reset.  Wait for
         * ATA_TMOUT_FF_WAIT[_LONG] on -ENODEV if link isn't
         * offline.
         *
         * Note that some PATA controllers (pata_ali) explode
         * if status register is read more than once when
         * there's no device attached.
         */
        if (ready == -ENODEV) {
            if (ata_link_online(link))
                ready = 0;
            else if ((link->ap->flags & ATA_FLAG_SATA) &&
                 !ata_link_offline(link) &&
                 time_before(now, nodev_deadline))
                ready = 0;
        }

        if (ready)
            return ready;
        if (time_after(now, deadline))
            return -EBUSY;

        if (!warned && time_after(now, start + 5 * HZ) &&
            (deadline - now > 3 * HZ)) {
            ata_link_warn(link,
                "link is slow to respond, please be patient "
                "(ready=%d)\n", tmp);
            warned = 1;
        }

        ata_msleep(link->ap, 50);
    }
}

int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
                int (*check_ready)(struct ata_link *link))
{
    ata_msleep(link->ap, ATA_WAIT_AFTER_RESET);

    return ata_wait_ready(link, deadline, check_ready);
}

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;
    }
}

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.
         */
        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;
}

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_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);
}

int ata_std_prereset(struct ata_link *link, unsigned long deadline)
{
    struct ata_port *ap = link->ap;
    struct ata_eh_context *ehc = &link->eh_context;
    const unsigned long *timing = sata_ehc_deb_timing(ehc);
    int rc;

    /* if we're about to do hardreset, nothing more to do */
    if (ehc->i.action & ATA_EH_HARDRESET)
        return 0;

    /* if SATA, resume link */
    if (ap->flags & ATA_FLAG_SATA) {
        rc = sata_link_resume(link, timing, deadline);
        /* whine about phy resume failure but proceed */
        if (rc && rc != -EOPNOTSUPP)
            ata_link_warn(link,
                      "failed to resume link for reset (errno=%d)\n",
                      rc);
    }

    /* no point in trying softreset on offline link */
    if (ata_phys_link_offline(link))
        ehc->i.action &= ~ATA_EH_SOFTRESET;

    return 0;
}

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;
}

int sata_std_hardreset(struct ata_link *link, unsigned int *class,
               unsigned long deadline)
{
    const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
    bool online;
    int rc;

    /* do hardreset */
    rc = sata_link_hardreset(link, timing, deadline, &online, NULL);
    return online ? -EAGAIN : rc;
}

void ata_std_postreset(struct ata_link *link, unsigned int *classes)
{
    u32 serror;

    DPRINTK("ENTER\n");

    /* reset complete, clear SError */
    if (!sata_scr_read(link, SCR_ERROR, &serror))
        sata_scr_write(link, SCR_ERROR, serror);

    /* print link status */
    sata_print_link_status(link);

    DPRINTK("EXIT\n");
}

static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
                   const u16 *new_id)
{
    const u16 *old_id = dev->id;
    unsigned char model[2][ATA_ID_PROD_LEN + 1];
    unsigned char serial[2][ATA_ID_SERNO_LEN + 1];

    if (dev->class != new_class) {
        ata_dev_info(dev, "class mismatch %d != %d\n",
                 dev->class, new_class);
        return 0;
    }

    ata_id_c_string(old_id, model[0], ATA_ID_PROD, sizeof(model[0]));
    ata_id_c_string(new_id, model[1], ATA_ID_PROD, sizeof(model[1]));
    ata_id_c_string(old_id, serial[0], ATA_ID_SERNO, sizeof(serial[0]));
    ata_id_c_string(new_id, serial[1], ATA_ID_SERNO, sizeof(serial[1]));

    if (strcmp(model[0], model[1])) {
        ata_dev_info(dev, "model number mismatch '%s' != '%s'\n",
                 model[0], model[1]);
        return 0;
    }

    if (strcmp(serial[0], serial[1])) {
        ata_dev_info(dev, "serial number mismatch '%s' != '%s'\n",
                 serial[0], serial[1]);
        return 0;
    }

    return 1;
}

int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
{
    unsigned int class = dev->class;
    u16 *id = (void *)dev->link->ap->sector_buf;
    int rc;

    /* read ID data */
    rc = ata_dev_read_id(dev, &class, readid_flags, id);
    if (rc)
        return rc;

    /* is the device still there? */
    if (!ata_dev_same_device(dev, class, id))
        return -ENODEV;

    memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
    return 0;
}

int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
               unsigned int readid_flags)
{
    u64 n_sectors = dev->n_sectors;
    u64 n_native_sectors = dev->n_native_sectors;
    int rc;

    if (!ata_dev_enabled(dev))
        return -ENODEV;

    /* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
    if (ata_class_enabled(new_class) &&
        new_class != ATA_DEV_ATA &&
        new_class != ATA_DEV_ATAPI &&
        new_class != ATA_DEV_SEMB) {
        ata_dev_info(dev, "class mismatch %u != %u\n",
                 dev->class, new_class);
        rc = -ENODEV;
        goto fail;
    }

    /* re-read ID */
    rc = ata_dev_reread_id(dev, readid_flags);
    if (rc)
        goto fail;

    /* configure device according to the new ID */
    rc = ata_dev_configure(dev);
    if (rc)
        goto fail;

    /* verify n_sectors hasn't changed */
    if (dev->class != ATA_DEV_ATA || !n_sectors ||
        dev->n_sectors == n_sectors)
        return 0;

    /* n_sectors has changed */
    ata_dev_warn(dev, "n_sectors mismatch %llu != %llu\n",
             (unsigned long long)n_sectors,
             (unsigned long long)dev->n_sectors);

    /*
     * Something could have caused HPA to be unlocked
     * involuntarily.  If n_native_sectors hasn't changed and the
     * new size matches it, keep the device.
     */
    if (dev->n_native_sectors == n_native_sectors &&
        dev->n_sectors > n_sectors && dev->n_sectors == n_native_sectors) {
        ata_dev_warn(dev,
                 "new n_sectors matches native, probably "
                 "late HPA unlock, n_sectors updated\n");
        /* use the larger n_sectors */
        return 0;
    }

    /*
     * Some BIOSes boot w/o HPA but resume w/ HPA locked.  Try
     * unlocking HPA in those cases.
     *
     * https://bugzilla.kernel.org/show_bug.cgi?id=15396
     */
    if (dev->n_native_sectors == n_native_sectors &&
        dev->n_sectors < n_sectors && n_sectors == n_native_sectors &&
        !(dev->horkage & ATA_HORKAGE_BROKEN_HPA)) {
        ata_dev_warn(dev,
                 "old n_sectors matches native, probably "
                 "late HPA lock, will try to unlock HPA\n");
        /* try unlocking HPA */
        dev->flags |= ATA_DFLAG_UNLOCK_HPA;
        rc = -EIO;
    } else
        rc = -ENODEV;

    /* restore original n_[native_]sectors and fail */
    dev->n_native_sectors = n_native_sectors;
    dev->n_sectors = n_sectors;
 fail:
    ata_dev_err(dev, "revalidation failed (errno=%d)\n", rc);
    return rc;
}

struct ata_blacklist_entry {
    const char *model_num;
    const char *model_rev;
    unsigned long horkage;
};

static const struct ata_blacklist_entry ata_device_blacklist [] = {
    /* Devices with DMA related problems under Linux */
    { "WDC AC11000H",   NULL,       ATA_HORKAGE_NODMA },
    { "WDC AC22100H",   NULL,       ATA_HORKAGE_NODMA },
    { "WDC AC32500H",   NULL,       ATA_HORKAGE_NODMA },
    { "WDC AC33100H",   NULL,       ATA_HORKAGE_NODMA },
    { "WDC AC31600H",   NULL,       ATA_HORKAGE_NODMA },
    { "WDC AC32100H",   "24.09P07", ATA_HORKAGE_NODMA },
    { "WDC AC23200L",   "21.10N21", ATA_HORKAGE_NODMA },
    { "Compaq CRD-8241B",   NULL,       ATA_HORKAGE_NODMA },
    { "CRD-8400B",      NULL,       ATA_HORKAGE_NODMA },
    { "CRD-848[02]B",   NULL,       ATA_HORKAGE_NODMA },
    { "CRD-84",     NULL,       ATA_HORKAGE_NODMA },
    { "SanDisk SDP3B",  NULL,       ATA_HORKAGE_NODMA },
    { "SanDisk SDP3B-64",   NULL,       ATA_HORKAGE_NODMA },
    { "SANYO CD-ROM CRD",   NULL,       ATA_HORKAGE_NODMA },
    { "HITACHI CDR-8",  NULL,       ATA_HORKAGE_NODMA },
    { "HITACHI CDR-8[34]35",NULL,       ATA_HORKAGE_NODMA },
    { "Toshiba CD-ROM XM-6202B", NULL,  ATA_HORKAGE_NODMA },
    { "TOSHIBA CD-ROM XM-1702BC", NULL, ATA_HORKAGE_NODMA },
    { "CD-532E-A",      NULL,       ATA_HORKAGE_NODMA },
    { "E-IDE CD-ROM CR-840",NULL,       ATA_HORKAGE_NODMA },
    { "CD-ROM Drive/F5A",   NULL,       ATA_HORKAGE_NODMA },
    { "WPI CDD-820",    NULL,       ATA_HORKAGE_NODMA },
    { "SAMSUNG CD-ROM SC-148C", NULL,   ATA_HORKAGE_NODMA },
    { "SAMSUNG CD-ROM SC",  NULL,       ATA_HORKAGE_NODMA },
    { "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
    { "_NEC DV5800A",   NULL,       ATA_HORKAGE_NODMA },
    { "SAMSUNG CD-ROM SN-124", "N001",  ATA_HORKAGE_NODMA },
    { "Seagate STT20000A", NULL,        ATA_HORKAGE_NODMA },
    { " 2GB ATA Flash Disk", "ADMA428M",    ATA_HORKAGE_NODMA },
    /* Odd clown on sil3726/4726 PMPs */
    { "Config  Disk",   NULL,       ATA_HORKAGE_DISABLE },

    /* Weird ATAPI devices */
    { "TORiSAN DVD-ROM DRD-N216", NULL, ATA_HORKAGE_MAX_SEC_128 },
    { "QUANTUM DAT    DAT72-000", NULL, ATA_HORKAGE_ATAPI_MOD16_DMA },

    /* Devices we expect to fail diagnostics */

    /* Devices where NCQ should be avoided */
    /* NCQ is slow */
    { "WDC WD740ADFD-00",   NULL,       ATA_HORKAGE_NONCQ },
    { "WDC WD740ADFD-00NLR1", NULL,     ATA_HORKAGE_NONCQ, },
    /* http://thread.gmane.org/gmane.linux.ide/14907 */
    { "FUJITSU MHT2060BH",  NULL,       ATA_HORKAGE_NONCQ },
    /* NCQ is broken */
    { "Maxtor *",       "BANC*",    ATA_HORKAGE_NONCQ },
    { "Maxtor 7V300F0", "VA111630", ATA_HORKAGE_NONCQ },
    { "ST380817AS",     "3.42",     ATA_HORKAGE_NONCQ },
    { "ST3160023AS",    "3.42",     ATA_HORKAGE_NONCQ },
    { "OCZ CORE_SSD",   "02.10104", ATA_HORKAGE_NONCQ },

    /* Seagate NCQ + FLUSH CACHE firmware bug */
    { "ST31500341AS",   "SD1[5-9]", ATA_HORKAGE_NONCQ |
                        ATA_HORKAGE_FIRMWARE_WARN },

    { "ST31000333AS",   "SD1[5-9]", ATA_HORKAGE_NONCQ |
                        ATA_HORKAGE_FIRMWARE_WARN },

    { "ST3640[36]23AS", "SD1[5-9]", ATA_HORKAGE_NONCQ |
                        ATA_HORKAGE_FIRMWARE_WARN },

    { "ST3320[68]13AS", "SD1[5-9]", ATA_HORKAGE_NONCQ |
                        ATA_HORKAGE_FIRMWARE_WARN },

    /* Blacklist entries taken from Silicon Image 3124/3132
       Windows driver .inf file - also several Linux problem reports */
    { "HTS541060G9SA00",    "MB3OC60D",     ATA_HORKAGE_NONCQ, },
    { "HTS541080G9SA00",    "MB4OC60D",     ATA_HORKAGE_NONCQ, },
    { "HTS541010G9SA00",    "MBZOC60D",     ATA_HORKAGE_NONCQ, },

    /* https://bugzilla.kernel.org/show_bug.cgi?id=15573 */
    { "C300-CTFDDAC128MAG", "0001",     ATA_HORKAGE_NONCQ, },

    /* devices which puke on READ_NATIVE_MAX */
    { "HDS724040KLSA80",    "KFAOA20N", ATA_HORKAGE_BROKEN_HPA, },
    { "WDC WD3200JD-00KLB0", "WD-WCAMR1130137", ATA_HORKAGE_BROKEN_HPA },
    { "WDC WD2500JD-00HBB0", "WD-WMAL71490727", ATA_HORKAGE_BROKEN_HPA },
    { "MAXTOR 6L080L4", "A93.0500", ATA_HORKAGE_BROKEN_HPA },

    /* this one allows HPA unlocking but fails IOs on the area */
    { "OCZ-VERTEX",         "1.30", ATA_HORKAGE_BROKEN_HPA },

    /* Devices which report 1 sector over size HPA */
    { "ST340823A",      NULL,       ATA_HORKAGE_HPA_SIZE, },
    { "ST320413A",      NULL,       ATA_HORKAGE_HPA_SIZE, },
    { "ST310211A",      NULL,       ATA_HORKAGE_HPA_SIZE, },

    /* Devices which get the IVB wrong */
    { "QUANTUM FIREBALLlct10 05", "A03.0900", ATA_HORKAGE_IVB, },
    /* Maybe we should just blacklist TSSTcorp... */
    { "TSSTcorp CDDVDW SH-S202[HJN]", "SB0[01]",  ATA_HORKAGE_IVB, },

    /* Devices that do not need bridging limits applied */
    { "MTRON MSP-SATA*",        NULL,   ATA_HORKAGE_BRIDGE_OK, },
    { "BUFFALO HD-QSU2/R5",     NULL,   ATA_HORKAGE_BRIDGE_OK, },

    /* Devices which aren't very happy with higher link speeds */
    { "WD My Book",         NULL,   ATA_HORKAGE_1_5_GBPS, },
    { "Seagate FreeAgent GoFlex",   NULL,   ATA_HORKAGE_1_5_GBPS, },

    /*
     * Devices which choke on SETXFER.  Applies only if both the
     * device and controller are SATA.
     */
    { "PIONEER DVD-RW  DVRTD08",    NULL,   ATA_HORKAGE_NOSETXFER },
    { "PIONEER DVD-RW  DVRTD08A",   NULL,   ATA_HORKAGE_NOSETXFER },
    { "PIONEER DVD-RW  DVR-215",    NULL,   ATA_HORKAGE_NOSETXFER },
    { "PIONEER DVD-RW  DVR-212D",   NULL,   ATA_HORKAGE_NOSETXFER },
    { "PIONEER DVD-RW  DVR-216D",   NULL,   ATA_HORKAGE_NOSETXFER },

    /* End Marker */
    { }
};

static int glob_match (const char *text, const char *pattern)
{
    do {
        /* Match single character or a '?' wildcard */
        if (*text == *pattern || *pattern == '?') {
            if (!*pattern++)
                return 0;  /* End of both strings: match */
        } else {
            /* Match single char against a '[' bracketed ']' pattern set */
            if (!*text || *pattern != '[')
                break;  /* Not a pattern set */
            while (*++pattern && *pattern != ']' && *text != *pattern) {
                if (*pattern == '-' && *(pattern - 1) != '[')
                    if (*text > *(pattern - 1) && *text < *(pattern + 1)) {
                        ++pattern;
                        break;
                    }
            }
            if (!*pattern || *pattern == ']')
                return 1;  /* No match */
            while (*pattern && *pattern++ != ']');
        }
    } while (*++text && *pattern);

    /* Match any run of chars against a '*' wildcard */
    if (*pattern == '*') {
        if (!*++pattern)
            return 0;  /* Match: avoid recursion at end of pattern */
        /* Loop to handle additional pattern chars after the wildcard */
        while (*text) {
            if (glob_match(text, pattern) == 0)
                return 0;  /* Remainder matched */
            ++text;  /* Absorb (match) this char and try again */
        }
    }
    if (!*text && !*pattern)
        return 0;  /* End of both strings: match */
    return 1;  /* No match */
}

static unsigned long ata_dev_blacklisted(const struct ata_device *dev)
{
    unsigned char model_num[ATA_ID_PROD_LEN + 1];
    unsigned char model_rev[ATA_ID_FW_REV_LEN + 1];
    const struct ata_blacklist_entry *ad = ata_device_blacklist;

    ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
    ata_id_c_string(dev->id, model_rev, ATA_ID_FW_REV, sizeof(model_rev));

    while (ad->model_num) {
        if (!glob_match(model_num, ad->model_num)) {
            if (ad->model_rev == NULL)
                return ad->horkage;
            if (!glob_match(model_rev, ad->model_rev))
                return ad->horkage;
        }
        ad++;
    }
    return 0;
}

static int ata_dma_blacklisted(const struct ata_device *dev)
{
    /* We don't support polling DMA.
     * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
     * if the LLDD handles only interrupts in the HSM_ST_LAST state.
     */
    if ((dev->link->ap->flags & ATA_FLAG_PIO_POLLING) &&
        (dev->flags & ATA_DFLAG_CDB_INTR))
        return 1;
    return (dev->horkage & ATA_HORKAGE_NODMA) ? 1 : 0;
}

static int ata_is_40wire(struct ata_device *dev)
{
    if (dev->horkage & ATA_HORKAGE_IVB)
        return ata_drive_40wire_relaxed(dev->id);
    return ata_drive_40wire(dev->id);
}

static int cable_is_40wire(struct ata_port *ap)
{
    struct ata_link *link;
    struct ata_device *dev;

    /* If the controller thinks we are 40 wire, we are. */
    if (ap->cbl == ATA_CBL_PATA40)
        return 1;

    /* If the controller thinks we are 80 wire, we are. */
    if (ap->cbl == ATA_CBL_PATA80 || ap->cbl == ATA_CBL_SATA)
        return 0;

    /* If the system is known to be 40 wire short cable (eg
     * laptop), then we allow 80 wire modes even if the drive
     * isn't sure.
     */
    if (ap->cbl == ATA_CBL_PATA40_SHORT)
        return 0;

    /* If the controller doesn't know, we scan.
     *
     * Note: We look for all 40 wire detects at this point.  Any
     *       80 wire detect is taken to be 80 wire cable because
     * - in many setups only the one drive (slave if present) will
     *   give a valid detect
     * - if you have a non detect capable drive you don't want it
     *   to colour the choice
     */
    ata_for_each_link(link, ap, EDGE) {
        ata_for_each_dev(dev, link, ENABLED) {
            if (!ata_is_40wire(dev))
                return 0;
        }
    }
    return 1;
}

static void ata_dev_xfermask(struct ata_device *dev)
{
    struct ata_link *link = dev->link;
    struct ata_port *ap = link->ap;
    struct ata_host *host = ap->host;
    unsigned long xfer_mask;

    /* controller modes available */
    xfer_mask = ata_pack_xfermask(ap->pio_mask,
                      ap->mwdma_mask, ap->udma_mask);

    /* drive modes available */
    xfer_mask &= ata_pack_xfermask(dev->pio_mask,
                       dev->mwdma_mask, dev->udma_mask);
    xfer_mask &= ata_id_xfermask(dev->id);

    /*
     *  CFA Advanced TrueIDE timings are not allowed on a shared
     *  cable
     */
    if (ata_dev_pair(dev)) {
        /* No PIO5 or PIO6 */
        xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
        /* No MWDMA3 or MWDMA 4 */
        xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
    }

    if (ata_dma_blacklisted(dev)) {
        xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
        ata_dev_warn(dev,
                 "device is on DMA blacklist, disabling DMA\n");
    }

    if ((host->flags & ATA_HOST_SIMPLEX) &&
        host->simplex_claimed && host->simplex_claimed != ap) {
        xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
        ata_dev_warn(dev,
                 "simplex DMA is claimed by other device, disabling DMA\n");
    }

    if (ap->flags & ATA_FLAG_NO_IORDY)
        xfer_mask &= ata_pio_mask_no_iordy(dev);

    if (ap->ops->mode_filter)
        xfer_mask = ap->ops->mode_filter(dev, xfer_mask);

    /* Apply cable rule here.  Don't apply it early because when
     * we handle hot plug the cable type can itself change.
     * Check this last so that we know if the transfer rate was
     * solely limited by the cable.
     * Unknown or 80 wire cables reported host side are checked
     * drive side as well. Cases where we know a 40wire cable
     * is used safely for 80 are not checked here.
     */
    if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
        /* UDMA/44 or higher would be available */
        if (cable_is_40wire(ap)) {
            ata_dev_warn(dev,
                     "limited to UDMA/33 due to 40-wire cable\n");
            xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
        }

    ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
                &dev->mwdma_mask, &dev->udma_mask);
}

static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
{
    struct ata_taskfile tf;
    unsigned int err_mask;

    /* set up set-features taskfile */
    DPRINTK("set features - xfer mode\n");

    /* Some controllers and ATAPI devices show flaky interrupt
     * behavior after setting xfer mode.  Use polling instead.
     */
    ata_tf_init(dev, &tf);
    tf.command = ATA_CMD_SET_FEATURES;
    tf.feature = SETFEATURES_XFER;
    tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_POLLING;
    tf.protocol = ATA_PROT_NODATA;
    /* If we are using IORDY we must send the mode setting command */
    if (ata_pio_need_iordy(dev))
        tf.nsect = dev->xfer_mode;
    /* If the device has IORDY and the controller does not - turn it off */
    else if (ata_id_has_iordy(dev->id))
        tf.nsect = 0x01;
    else /* In the ancient relic department - skip all of this */
        return 0;

    err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);

    DPRINTK("EXIT, err_mask=%x\n", err_mask);
    return err_mask;
}

unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable, u8 feature)
{
    struct ata_taskfile tf;
    unsigned int err_mask;

    /* set up set-features taskfile */
    DPRINTK("set features - SATA features\n");

    ata_tf_init(dev, &tf);
    tf.command = ATA_CMD_SET_FEATURES;
    tf.feature = enable;
    tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
    tf.protocol = ATA_PROT_NODATA;
    tf.nsect = feature;

    err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);

    DPRINTK("EXIT, err_mask=%x\n", err_mask);
    return err_mask;
}
EXPORT_SYMBOL_GPL(ata_dev_set_feature);

static unsigned int ata_dev_init_params(struct ata_device *dev,
                    u16 heads, u16 sectors)
{
    struct ata_taskfile tf;
    unsigned int err_mask;

    /* Number of sectors per track 1-255. Number of heads 1-16 */
    if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
        return AC_ERR_INVALID;

    /* set up init dev params taskfile */
    DPRINTK("init dev params \n");

    ata_tf_init(dev, &tf);
    tf.command = ATA_CMD_INIT_DEV_PARAMS;
    tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
    tf.protocol = ATA_PROT_NODATA;
    tf.nsect = sectors;
    tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */

    err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
    /* A clean abort indicates an original or just out of spec drive
       and we should continue as we issue the setup based on the
       drive reported working geometry */
    if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
        err_mask = 0;

    DPRINTK("EXIT, err_mask=%x\n", err_mask);
    return err_mask;
}

void ata_sg_clean(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;
    struct scatterlist *sg = qc->sg;
    int dir = qc->dma_dir;

    WARN_ON_ONCE(sg == NULL);

    VPRINTK("unmapping %u sg elements\n", qc->n_elem);

    if (qc->n_elem)
        dma_unmap_sg(ap->dev, sg, qc->orig_n_elem, dir);

    qc->flags &= ~ATA_QCFLAG_DMAMAP;
    qc->sg = NULL;
}

int atapi_check_dma(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;

    /* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
     * few ATAPI devices choke on such DMA requests.
     */
    if (!(qc->dev->horkage & ATA_HORKAGE_ATAPI_MOD16_DMA) &&
        unlikely(qc->nbytes & 15))
        return 1;

    if (ap->ops->check_atapi_dma)
        return ap->ops->check_atapi_dma(qc);

    return 0;
}

int ata_std_qc_defer(struct ata_queued_cmd *qc)
{
    struct ata_link *link = qc->dev->link;

    if (qc->tf.protocol == ATA_PROT_NCQ) {
        if (!ata_tag_valid(link->active_tag))
            return 0;
    } else {
        if (!ata_tag_valid(link->active_tag) && !link->sactive)
            return 0;
    }

    return ATA_DEFER_LINK;
}

void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }

void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
         unsigned int n_elem)
{
    qc->sg = sg;
    qc->n_elem = n_elem;
    qc->cursg = qc->sg;
}

static int ata_sg_setup(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;
    unsigned int n_elem;

    VPRINTK("ENTER, ata%u\n", ap->print_id);

    n_elem = dma_map_sg(ap->dev, qc->sg, qc->n_elem, qc->dma_dir);
    if (n_elem < 1)
        return -1;

    DPRINTK("%d sg elements mapped\n", n_elem);
    qc->orig_n_elem = qc->n_elem;
    qc->n_elem = n_elem;
    qc->flags |= ATA_QCFLAG_DMAMAP;

    return 0;
}

void swap_buf_le16(u16 *buf, unsigned int buf_words)
{
#ifdef __BIG_ENDIAN
    unsigned int i;

    for (i = 0; i < buf_words; i++)
        buf[i] = le16_to_cpu(buf[i]);
#endif /* __BIG_ENDIAN */
}

static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
{
    struct ata_queued_cmd *qc = NULL;
    unsigned int i;

    /* no command while frozen */
    if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
        return NULL;

    /* the last tag is reserved for internal command. */
    for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
        if (!test_and_set_bit(i, &ap->qc_allocated)) {
            qc = __ata_qc_from_tag(ap, i);
            break;
        }

    if (qc)
        qc->tag = i;

    return qc;
}

struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
{
    struct ata_port *ap = dev->link->ap;
    struct ata_queued_cmd *qc;

    qc = ata_qc_new(ap);
    if (qc) {
        qc->scsicmd = NULL;
        qc->ap = ap;
        qc->dev = dev;

        ata_qc_reinit(qc);
    }

    return qc;
}

void ata_qc_free(struct ata_queued_cmd *qc)
{
    struct ata_port *ap;
    unsigned int tag;

    WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
    ap = qc->ap;

    qc->flags = 0;
    tag = qc->tag;
    if (likely(ata_tag_valid(tag))) {
        qc->tag = ATA_TAG_POISON;
        clear_bit(tag, &ap->qc_allocated);
    }
}

void __ata_qc_complete(struct ata_queued_cmd *qc)
{
    struct ata_port *ap;
    struct ata_link *link;

    WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
    WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_ACTIVE));
    ap = qc->ap;
    link = qc->dev->link;

    if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
        ata_sg_clean(qc);

    /* command should be marked inactive atomically with qc completion */
    if (qc->tf.protocol == ATA_PROT_NCQ) {
        link->sactive &= ~(1 << qc->tag);
        if (!link->sactive)
            ap->nr_active_links--;
    } else {
        link->active_tag = ATA_TAG_POISON;
        ap->nr_active_links--;
    }

    /* clear exclusive status */
    if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
             ap->excl_link == link))
        ap->excl_link = NULL;

    /* atapi: mark qc as inactive to prevent the interrupt handler
     * from completing the command twice later, before the error handler
     * is called. (when rc != 0 and atapi request sense is needed)
     */
    qc->flags &= ~ATA_QCFLAG_ACTIVE;
    ap->qc_active &= ~(1 << qc->tag);

    /* call completion callback */
    qc->complete_fn(qc);
}

static void fill_result_tf(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;

    qc->result_tf.flags = qc->tf.flags;
    ap->ops->qc_fill_rtf(qc);
}

static void ata_verify_xfer(struct ata_queued_cmd *qc)
{
    struct ata_device *dev = qc->dev;

    if (ata_is_nodata(qc->tf.protocol))
        return;

    if ((dev->mwdma_mask || dev->udma_mask) && ata_is_pio(qc->tf.protocol))
        return;

    dev->flags &= ~ATA_DFLAG_DUBIOUS_XFER;
}

void ata_qc_complete(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;

    /* XXX: New EH and old EH use different mechanisms to
     * synchronize EH with regular execution path.
     *
     * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
     * Normal execution path is responsible for not accessing a
     * failed qc.  libata core enforces the rule by returning NULL
     * from ata_qc_from_tag() for failed qcs.
     *
     * Old EH depends on ata_qc_complete() nullifying completion
     * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
     * not synchronize with interrupt handler.  Only PIO task is
     * taken care of.
     */
    if (ap->ops->error_handler) {
        struct ata_device *dev = qc->dev;
        struct ata_eh_info *ehi = &dev->link->eh_info;

        if (unlikely(qc->err_mask))
            qc->flags |= ATA_QCFLAG_FAILED;

        /*
         * Finish internal commands without any further processing
         * and always with the result TF filled.
         */
        if (unlikely(ata_tag_internal(qc->tag))) {
            fill_result_tf(qc);
            __ata_qc_complete(qc);
            return;
        }

        /*
         * Non-internal qc has failed.  Fill the result TF and
         * summon EH.
         */
        if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
            fill_result_tf(qc);
            ata_qc_schedule_eh(qc);
            return;
        }

        WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);

        /* read result TF if requested */
        if (qc->flags & ATA_QCFLAG_RESULT_TF)
            fill_result_tf(qc);

        /* Some commands need post-processing after successful
         * completion.
         */
        switch (qc->tf.command) {
        case ATA_CMD_SET_FEATURES:
            if (qc->tf.feature != SETFEATURES_WC_ON &&
                qc->tf.feature != SETFEATURES_WC_OFF)
                break;
            /* fall through */
        case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
        case ATA_CMD_SET_MULTI: /* multi_count changed */
            /* revalidate device */
            ehi->dev_action[dev->devno] |= ATA_EH_REVALIDATE;
            ata_port_schedule_eh(ap);
            break;

        case ATA_CMD_SLEEP:
            dev->flags |= ATA_DFLAG_SLEEPING;
            break;
        }

        if (unlikely(dev->flags & ATA_DFLAG_DUBIOUS_XFER))
            ata_verify_xfer(qc);

        __ata_qc_complete(qc);
    } else {
        if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
            return;

        /* read result TF if failed or requested */
        if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
            fill_result_tf(qc);

        __ata_qc_complete(qc);
    }
}

int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active)
{
    int nr_done = 0;
    u32 done_mask;

    done_mask = ap->qc_active ^ qc_active;

    if (unlikely(done_mask & qc_active)) {
        ata_port_err(ap, "illegal qc_active transition (%08x->%08x)\n",
                 ap->qc_active, qc_active);
        return -EINVAL;
    }

    while (done_mask) {
        struct ata_queued_cmd *qc;
        unsigned int tag = __ffs(done_mask);

        qc = ata_qc_from_tag(ap, tag);
        if (qc) {
            ata_qc_complete(qc);
            nr_done++;
        }
        done_mask &= ~(1 << tag);
    }

    return nr_done;
}

void ata_qc_issue(struct ata_queued_cmd *qc)
{
    struct ata_port *ap = qc->ap;
    struct ata_link *link = qc->dev->link;
    u8 prot = qc->tf.protocol;

    /* Make sure only one non-NCQ command is outstanding.  The
     * check is skipped for old EH because it reuses active qc to
     * request ATAPI sense.
     */
    WARN_ON_ONCE(ap->ops->error_handler && ata_tag_valid(link->active_tag));

    if (ata_is_ncq(prot)) {
        WARN_ON_ONCE(link->sactive & (1 << qc->tag));

        if (!link->sactive)
            ap->nr_active_links++;
        link->sactive |= 1 << qc->tag;
    } else {
        WARN_ON_ONCE(link->sactive);

        ap->nr_active_links++;
        link->active_tag = qc->tag;
    }

    qc->flags |= ATA_QCFLAG_ACTIVE;
    ap->qc_active |= 1 << qc->tag;

    /*
     * We guarantee to LLDs that they will have at least one
     * non-zero sg if the command is a data command.
     */
    if (WARN_ON_ONCE(ata_is_data(prot) &&
             (!qc->sg || !qc->n_elem || !qc->nbytes)))
        goto sys_err;

    if (ata_is_dma(prot) || (ata_is_pio(prot) &&
                 (ap->flags & ATA_FLAG_PIO_DMA)))
        if (ata_sg_setup(qc))
            goto sys_err;

    /* if device is sleeping, schedule reset and abort the link */
    if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
        link->eh_info.action |= ATA_EH_RESET;
        ata_ehi_push_desc(&link->eh_info, "waking up from sleep");
        ata_link_abort(link);
        return;
    }

    ap->ops->qc_prep(qc);

    qc->err_mask |= ap->ops->qc_issue(qc);
    if (unlikely(qc->err_mask))
        goto err;
    return;

sys_err:
    qc->err_mask |= AC_ERR_SYSTEM;
err:
    ata_qc_complete(qc);
}

int sata_scr_valid(struct ata_link *link)
{
    struct ata_port *ap = link->ap;

    return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
}

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);
}

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);
}

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);
}

bool ata_phys_link_online(struct ata_link *link)
{
    u32 sstatus;

    if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
        ata_sstatus_online(sstatus))
        return true;
    return false;
}

bool ata_phys_link_offline(struct ata_link *link)
{
    u32 sstatus;

    if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
        !ata_sstatus_online(sstatus))
        return true;
    return false;
}

bool ata_link_online(struct ata_link *link)
{
    struct ata_link *slave = link->ap->slave_link;

    WARN_ON(link == slave); /* shouldn't be called on slave link */

    return ata_phys_link_online(link) ||
        (slave && ata_phys_link_online(slave));
}

bool ata_link_offline(struct ata_link *link)
{
    struct ata_link *slave = link->ap->slave_link;

    WARN_ON(link == slave); /* shouldn't be called on slave link */

    return ata_phys_link_offline(link) &&
        (!slave || ata_phys_link_offline(slave));
}

#ifdef CONFIG_PM
static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg,
                   unsigned int action, unsigned int ehi_flags,
                   int *async)
{
    struct ata_link *link;
    unsigned long flags;
    int rc = 0;

    /* Previous resume operation might still be in
     * progress.  Wait for PM_PENDING to clear.
     */
    if (ap->pflags & ATA_PFLAG_PM_PENDING) {
        if (async) {
            *async = -EAGAIN;
            return 0;
        }
        ata_port_wait_eh(ap);
        WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
    }

    /* request PM ops to EH */
    spin_lock_irqsave(ap->lock, flags);

    ap->pm_mesg = mesg;
    if (async)
        ap->pm_result = async;
    else
        ap->pm_result = &rc;

    ap->pflags |= ATA_PFLAG_PM_PENDING;
    ata_for_each_link(link, ap, HOST_FIRST) {
        link->eh_info.action |= action;
        link->eh_info.flags |= ehi_flags;
    }

    ata_port_schedule_eh(ap);

    spin_unlock_irqrestore(ap->lock, flags);

    /* wait and check result */
    if (!async) {
        ata_port_wait_eh(ap);
        WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
    }

    return rc;
}

static int __ata_port_suspend_common(struct ata_port *ap, pm_message_t mesg, int *async)
{
    unsigned int ehi_flags = ATA_EHI_QUIET;
    int rc;

    /*
     * On some hardware, device fails to respond after spun down
     * for suspend.  As the device won't be used before being
     * resumed, we don't need to touch the device.  Ask EH to skip
     * the usual stuff and proceed directly to suspend.
     *
     * http://thread.gmane.org/gmane.linux.ide/46764
     */
    if (mesg.event == PM_EVENT_SUSPEND)
        ehi_flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_NO_RECOVERY;

    rc = ata_port_request_pm(ap, mesg, 0, ehi_flags, async);
    return rc;
}

static int ata_port_suspend_common(struct device *dev, pm_message_t mesg)
{
    struct ata_port *ap = to_ata_port(dev);

    return __ata_port_suspend_common(ap, mesg, NULL);
}

static int ata_port_suspend(struct device *dev)
{
    if (pm_runtime_suspended(dev))
        return 0;

    return ata_port_suspend_common(dev, PMSG_SUSPEND);
}

static int ata_port_do_freeze(struct device *dev)
{
    if (pm_runtime_suspended(dev))
        pm_runtime_resume(dev);

    return ata_port_suspend_common(dev, PMSG_FREEZE);
}

static int ata_port_poweroff(struct device *dev)
{
    if (pm_runtime_suspended(dev))
        return 0;

    return ata_port_suspend_common(dev, PMSG_HIBERNATE);
}

static int __ata_port_resume_common(struct ata_port *ap, int *async)
{
    int rc;

    rc = ata_port_request_pm(ap, PMSG_ON, ATA_EH_RESET,
        ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, async);
    return rc;
}

static int ata_port_resume_common(struct device *dev)
{
    struct ata_port *ap = to_ata_port(dev);

    return __ata_port_resume_common(ap, NULL);
}

static int ata_port_resume(struct device *dev)
{
    int rc;

    rc = ata_port_resume_common(dev);
    if (!rc) {
        pm_runtime_disable(dev);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);
    }

    return rc;
}

static int ata_port_runtime_idle(struct device *dev)
{
    return pm_runtime_suspend(dev);
}

static const struct dev_pm_ops ata_port_pm_ops = {
    .suspend = ata_port_suspend,
    .resume = ata_port_resume,
    .freeze = ata_port_do_freeze,
    .thaw = ata_port_resume,
    .poweroff = ata_port_poweroff,
    .restore = ata_port_resume,

    .runtime_suspend = ata_port_suspend,
    .runtime_resume = ata_port_resume_common,
    .runtime_idle = ata_port_runtime_idle,
};

/* sas ports don't participate in pm runtime management of ata_ports,
 * and need to resume ata devices at the domain level, not the per-port
 * level. sas suspend/resume is async to allow parallel port recovery
 * since sas has multiple ata_port instances per Scsi_Host.
 */
int ata_sas_port_async_suspend(struct ata_port *ap, int *async)
{
    return __ata_port_suspend_common(ap, PMSG_SUSPEND, async);
}
EXPORT_SYMBOL_GPL(ata_sas_port_async_suspend);

int ata_sas_port_async_resume(struct ata_port *ap, int *async)
{
    return __ata_port_resume_common(ap, async);
}
EXPORT_SYMBOL_GPL(ata_sas_port_async_resume);


int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
{
    host->dev->power.power_state = mesg;
    return 0;
}

void ata_host_resume(struct ata_host *host)
{
    host->dev->power.power_state = PMSG_ON;
}
#endif

struct device_type ata_port_type = {
    .name = "ata_port",
#ifdef CONFIG_PM
    .pm = &ata_port_pm_ops,
#endif
};

void ata_dev_init(struct ata_device *dev)
{
    struct ata_link *link = ata_dev_phys_link(dev);
    struct ata_port *ap = link->ap;
    unsigned long flags;

    /* SATA spd limit is bound to the attached device, reset together */
    link->sata_spd_limit = link->hw_sata_spd_limit;
    link->sata_spd = 0;

    /* High bits of dev->flags are used to record warm plug
     * requests which occur asynchronously.  Synchronize using
     * host lock.
     */
    spin_lock_irqsave(ap->lock, flags);
    dev->flags &= ~ATA_DFLAG_INIT_MASK;
    dev->horkage = 0;
    spin_unlock_irqrestore(ap->lock, flags);

    memset((void *)dev + ATA_DEVICE_CLEAR_BEGIN, 0,
           ATA_DEVICE_CLEAR_END - ATA_DEVICE_CLEAR_BEGIN);
    dev->pio_mask = UINT_MAX;
    dev->mwdma_mask = UINT_MAX;
    dev->udma_mask = UINT_MAX;
}

void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
{
    int i;

    /* clear everything except for devices */
    memset((void *)link + ATA_LINK_CLEAR_BEGIN, 0,
           ATA_LINK_CLEAR_END - ATA_LINK_CLEAR_BEGIN);

    link->ap = ap;
    link->pmp = pmp;
    link->active_tag = ATA_TAG_POISON;
    link->hw_sata_spd_limit = UINT_MAX;

    /* can't use iterator, ap isn't initialized yet */
    for (i = 0; i < ATA_MAX_DEVICES; i++) {
        struct ata_device *dev = &link->device[i];

        dev->link = link;
        dev->devno = dev - link->device;
#ifdef CONFIG_ATA_ACPI
        dev->gtf_filter = ata_acpi_gtf_filter;
#endif
        ata_dev_init(dev);
    }
}

int sata_link_init_spd(struct ata_link *link)
{
    u8 spd;
    int rc;

    rc = sata_scr_read(link, SCR_CONTROL, &link->saved_scontrol);
    if (rc)
        return rc;

    spd = (link->saved_scontrol >> 4) & 0xf;
    if (spd)
        link->hw_sata_spd_limit &= (1 << spd) - 1;

    ata_force_link_limits(link);

    link->sata_spd_limit = link->hw_sata_spd_limit;

    return 0;
}

struct ata_port *ata_port_alloc(struct ata_host *host)
{
    struct ata_port *ap;

    DPRINTK("ENTER\n");

    ap = kzalloc(sizeof(*ap), GFP_KERNEL);
    if (!ap)
        return NULL;

    ap->pflags |= ATA_PFLAG_INITIALIZING | ATA_PFLAG_FROZEN;
    ap->lock = &host->lock;
    ap->print_id = -1;
    ap->host = host;
    ap->dev = host->dev;

#if defined(ATA_VERBOSE_DEBUG)
    /* turn on all debugging levels */
    ap->msg_enable = 0x00FF;
#elif defined(ATA_DEBUG)
    ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
#else
    ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
#endif

    mutex_init(&ap->scsi_scan_mutex);
    INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
    INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
    INIT_LIST_HEAD(&ap->eh_done_q);
    init_waitqueue_head(&ap->eh_wait_q);
    init_completion(&ap->park_req_pending);
    init_timer_deferrable(&ap->fastdrain_timer);
    ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
    ap->fastdrain_timer.data = (unsigned long)ap;

    ap->cbl = ATA_CBL_NONE;

    ata_link_init(ap, &ap->link, 0);

#ifdef ATA_IRQ_TRAP
    ap->stats.unhandled_irq = 1;
    ap->stats.idle_irq = 1;
#endif
    ata_sff_port_init(ap);

    return ap;
}

static void ata_host_release(struct device *gendev, void *res)
{
    struct ata_host *host = dev_get_drvdata(gendev);
    int i;

    for (i = 0; i < host->n_ports; i++) {
        struct ata_port *ap = host->ports[i];

        if (!ap)
            continue;

        if (ap->scsi_host)
            scsi_host_put(ap->scsi_host);

        kfree(ap->pmp_link);
        kfree(ap->slave_link);
        kfree(ap);
        host->ports[i] = NULL;
    }

    dev_set_drvdata(gendev, NULL);
}

struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
{
    struct ata_host *host;
    size_t sz;
    int i;

    DPRINTK("ENTER\n");

    if (!devres_open_group(dev, NULL, GFP_KERNEL))
        return NULL;

    /* alloc a container for our list of ATA ports (buses) */
    sz = sizeof(struct ata_host) + (max_ports + 1) * sizeof(void *);
    /* alloc a container for our list of ATA ports (buses) */
    host = devres_alloc(ata_host_release, sz, GFP_KERNEL);
    if (!host)
        goto err_out;

    devres_add(dev, host);
    dev_set_drvdata(dev, host);

    spin_lock_init(&host->lock);
    mutex_init(&host->eh_mutex);
    host->dev = dev;
    host->n_ports = max_ports;

    /* allocate ports bound to this host */
    for (i = 0; i < max_ports; i++) {
        struct ata_port *ap;

        ap = ata_port_alloc(host);
        if (!ap)
            goto err_out;

        ap->port_no = i;
        host->ports[i] = ap;
    }

    devres_remove_group(dev, NULL);
    return host;

 err_out:
    devres_release_group(dev, NULL);
    return NULL;
}

struct ata_host *ata_host_alloc_pinfo(struct device *dev,
                      const struct ata_port_info * const * ppi,
                      int n_ports)
{
    const struct ata_port_info *pi;
    struct ata_host *host;
    int i, j;

    host = ata_host_alloc(dev, n_ports);
    if (!host)
        return NULL;

    for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
        struct ata_port *ap = host->ports[i];

        if (ppi[j])
            pi = ppi[j++];

        ap->pio_mask = pi->pio_mask;
        ap->mwdma_mask = pi->mwdma_mask;
        ap->udma_mask = pi->udma_mask;
        ap->flags |= pi->flags;
        ap->link.flags |= pi->link_flags;
        ap->ops = pi->port_ops;

        if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
            host->ops = pi->port_ops;
    }

    return host;
}

int ata_slave_link_init(struct ata_port *ap)
{
    struct ata_link *link;

    WARN_ON(ap->slave_link);
    WARN_ON(ap->flags & ATA_FLAG_PMP);

    link = kzalloc(sizeof(*link), GFP_KERNEL);
    if (!link)
        return -ENOMEM;

    ata_link_init(ap, link, 1);
    ap->slave_link = link;
    return 0;
}

static void ata_host_stop(struct device *gendev, void *res)
{
    struct ata_host *host = dev_get_drvdata(gendev);
    int i;

    WARN_ON(!(host->flags & ATA_HOST_STARTED));

    for (i = 0; i < host->n_ports; i++) {
        struct ata_port *ap = host->ports[i];

        if (ap->ops->port_stop)
            ap->ops->port_stop(ap);
    }

    if (host->ops->host_stop)
        host->ops->host_stop(host);
}

static void ata_finalize_port_ops(struct ata_port_operations *ops)
{
    static DEFINE_SPINLOCK(lock);
    const struct ata_port_operations *cur;
    void **begin = (void **)ops;
    void **end = (void **)&ops->inherits;
    void **pp;

    if (!ops || !ops->inherits)
        return;

    spin_lock(&lock);

    for (cur = ops->inherits; cur; cur = cur->inherits) {
        void **inherit = (void **)cur;

        for (pp = begin; pp < end; pp++, inherit++)
            if (!*pp)
                *pp = *inherit;
    }

    for (pp = begin; pp < end; pp++)
        if (IS_ERR(*pp))
            *pp = NULL;

    ops->inherits = NULL;

    spin_unlock(&lock);
}

int ata_host_start(struct ata_host *host)
{
    int have_stop = 0;
    void *start_dr = NULL;
    int i, rc;

    if (host->flags & ATA_HOST_STARTED)
        return 0;

    ata_finalize_port_ops(host->ops);

    for (i = 0; i < host->n_ports; i++) {
        struct ata_port *ap = host->ports[i];

        ata_finalize_port_ops(ap->ops);

        if (!host->ops && !ata_port_is_dummy(ap))
            host->ops = ap->ops;

        if (ap->ops->port_stop)
            have_stop = 1;
    }

    if (host->ops->host_stop)
        have_stop = 1;

    if (have_stop) {
        start_dr = devres_alloc(ata_host_stop, 0, GFP_KERNEL);
        if (!start_dr)
            return -ENOMEM;
    }

    for (i = 0; i < host->n_ports; i++) {
        struct ata_port *ap = host->ports[i];

        if (ap->ops->port_start) {
            rc = ap->ops->port_start(ap);
            if (rc) {
                if (rc != -ENODEV)
                    dev_err(host->dev,
                        "failed to start port %d (errno=%d)\n",
                        i, rc);
                goto err_out;
            }
        }
        ata_eh_freeze_port(ap);
    }

    if (start_dr)
        devres_add(host->dev, start_dr);
    host->flags |= ATA_HOST_STARTED;
    return 0;

 err_out:
    while (--i >= 0) {
        struct ata_port *ap = host->ports[i];

        if (ap->ops->port_stop)
            ap->ops->port_stop(ap);
    }
    devres_free(start_dr);
    return rc;
}

void ata_host_init(struct ata_host *host, struct device *dev,
           struct ata_port_operations *ops)
{
    spin_lock_init(&host->lock);
    mutex_init(&host->eh_mutex);
    host->dev = dev;
    host->ops = ops;
}

void __ata_port_probe(struct ata_port *ap)
{
    struct ata_eh_info *ehi = &ap->link.eh_info;
    unsigned long flags;

    /* kick EH for boot probing */
    spin_lock_irqsave(ap->lock, flags);

    ehi->probe_mask |= ATA_ALL_DEVICES;
    ehi->action |= ATA_EH_RESET;
    ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;

    ap->pflags &= ~ATA_PFLAG_INITIALIZING;
    ap->pflags |= ATA_PFLAG_LOADING;
    ata_port_schedule_eh(ap);

    spin_unlock_irqrestore(ap->lock, flags);
}

int ata_port_probe(struct ata_port *ap)
{
    int rc = 0;

    if (ap->ops->error_handler) {
        __ata_port_probe(ap);
        ata_port_wait_eh(ap);
    } else {
        DPRINTK("ata%u: bus probe begin\n", ap->print_id);
        rc = ata_bus_probe(ap);
        DPRINTK("ata%u: bus probe end\n", ap->print_id);
    }
    return rc;
}


static void async_port_probe(void *data, async_cookie_t cookie)
{
    struct ata_port *ap = data;

    /*
     * If we're not allowed to scan this host in parallel,
     * we need to wait until all previous scans have completed
     * before going further.
     * Jeff Garzik says this is only within a controller, so we
     * don't need to wait for port 0, only for later ports.
     */
    if (!(ap->host->flags & ATA_HOST_PARALLEL_SCAN) && ap->port_no != 0)
        async_synchronize_cookie(cookie);

    (void)ata_port_probe(ap);

    /* in order to keep device order, we need to synchronize at this point */
    async_synchronize_cookie(cookie);

    ata_scsi_scan_host(ap, 1);
}

int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
{
    int i, rc;

    /* host must have been started */
    if (!(host->flags & ATA_HOST_STARTED)) {
        dev_err(host->dev, "BUG: trying to register unstarted host\n");
        WARN_ON(1);
        return -EINVAL;
    }

    /* Blow away unused ports.  This happens when LLD can't
     * determine the exact number of ports to allocate at
     * allocation time.
     */
    for (i = host->n_ports; host->ports[i]; i++)
        kfree(host->ports[i]);

    /* give ports names and add SCSI hosts */
    for (i = 0; i < host->n_ports; i++)
        host->ports[i]->print_id = atomic_inc_return(&ata_print_id);


    /* Create associated sysfs transport objects  */
    for (i = 0; i < host->n_ports; i++) {
        rc = ata_tport_add(host->dev,host->ports[i]);
        if (rc) {
            goto err_tadd;
        }
    }

    rc = ata_scsi_add_hosts(host, sht);
    if (rc)
        goto err_tadd;

    /* set cable, sata_spd_limit and report */
    for (i = 0; i < host->n_ports; i++) {
        struct ata_port *ap = host->ports[i];
        unsigned long xfer_mask;

        /* set SATA cable type if still unset */
        if (ap->cbl == ATA_CBL_NONE && (ap->flags & ATA_FLAG_SATA))
            ap->cbl = ATA_CBL_SATA;

        /* init sata_spd_limit to the current value */
        sata_link_init_spd(&ap->link);
        if (ap->slave_link)
            sata_link_init_spd(ap->slave_link);

        /* print per-port info to dmesg */
        xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
                          ap->udma_mask);

        if (!ata_port_is_dummy(ap)) {
            ata_port_info(ap, "%cATA max %s %s\n",
                      (ap->flags & ATA_FLAG_SATA) ? 'S' : 'P',
                      ata_mode_string(xfer_mask),
                      ap->link.eh_info.desc);
            ata_ehi_clear_desc(&ap->link.eh_info);
        } else
            ata_port_info(ap, "DUMMY\n");
    }

    /* perform each probe asynchronously */
    for (i = 0; i < host->n_ports; i++) {
        struct ata_port *ap = host->ports[i];
        async_schedule(async_port_probe, ap);
    }

    return 0;

 err_tadd:
    while (--i >= 0) {
        ata_tport_delete(host->ports[i]);
    }
    return rc;

}

int ata_host_activate(struct ata_host *host, int irq,
              irq_handler_t irq_handler, unsigned long irq_flags,
              struct scsi_host_template *sht)
{
    int i, rc;

    rc = ata_host_start(host);
    if (rc)
        return rc;

    /* Special case for polling mode */
    if (!irq) {
        WARN_ON(irq_handler);
        return ata_host_register(host, sht);
    }

    rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
                  dev_driver_string(host->dev), host);
    if (rc)
        return rc;

    for (i = 0; i < host->n_ports; i++)
        ata_port_desc(host->ports[i], "irq %d", irq);

    rc = ata_host_register(host, sht);
    /* if failed, just free the IRQ and leave ports alone */
    if (rc)
        devm_free_irq(host->dev, irq, host);

    return rc;
}

static void ata_port_detach(struct ata_port *ap)
{
    unsigned long flags;

    if (!ap->ops->error_handler)
        goto skip_eh;

    /* tell EH we're leaving & flush EH */
    spin_lock_irqsave(ap->lock, flags);
    ap->pflags |= ATA_PFLAG_UNLOADING;
    ata_port_schedule_eh(ap);
    spin_unlock_irqrestore(ap->lock, flags);

    /* wait till EH commits suicide */
    ata_port_wait_eh(ap);

    /* it better be dead now */
    WARN_ON(!(ap->pflags & ATA_PFLAG_UNLOADED));

    cancel_delayed_work_sync(&ap->hotplug_task);

 skip_eh:
    if (ap->pmp_link) {
        int i;
        for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
            ata_tlink_delete(&ap->pmp_link[i]);
    }
    ata_tport_delete(ap);

    /* remove the associated SCSI host */
    scsi_remove_host(ap->scsi_host);
}

void ata_host_detach(struct ata_host *host)
{
    int i;

    for (i = 0; i < host->n_ports; i++)
        ata_port_detach(host->ports[i]);

    /* the host is dead now, dissociate ACPI */
    ata_acpi_dissociate(host);
}

#ifdef CONFIG_PCI

void ata_pci_remove_one(struct pci_dev *pdev)
{
    struct device *dev = &pdev->dev;
    struct ata_host *host = dev_get_drvdata(dev);

    ata_host_detach(host);
}

/* move to PCI subsystem */
int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
{
    unsigned long tmp = 0;

    switch (bits->width) {
    case 1: {
        u8 tmp8 = 0;
        pci_read_config_byte(pdev, bits->reg, &tmp8);
        tmp = tmp8;
        break;
    }
    case 2: {
        u16 tmp16 = 0;
        pci_read_config_word(pdev, bits->reg, &tmp16);
        tmp = tmp16;
        break;
    }
    case 4: {
        u32 tmp32 = 0;
        pci_read_config_dword(pdev, bits->reg, &tmp32);
        tmp = tmp32;
        break;
    }

    default:
        return -EINVAL;
    }

    tmp &= bits->mask;

    return (tmp == bits->val) ? 1 : 0;
}

#ifdef CONFIG_PM
void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
    pci_save_state(pdev);
    pci_disable_device(pdev);

    if (mesg.event & PM_EVENT_SLEEP)
        pci_set_power_state(pdev, PCI_D3hot);
}

int ata_pci_device_do_resume(struct pci_dev *pdev)
{
    int rc;

    pci_set_power_state(pdev, PCI_D0);
    pci_restore_state(pdev);

    rc = pcim_enable_device(pdev);
    if (rc) {
        dev_err(&pdev->dev,
            "failed to enable device after resume (%d)\n", rc);
        return rc;
    }

    pci_set_master(pdev);
    return 0;
}

int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
    struct ata_host *host = dev_get_drvdata(&pdev->dev);
    int rc = 0;

    rc = ata_host_suspend(host, mesg);
    if (rc)
        return rc;

    ata_pci_device_do_suspend(pdev, mesg);

    return 0;
}

int ata_pci_device_resume(struct pci_dev *pdev)
{
    struct ata_host *host = dev_get_drvdata(&pdev->dev);
    int rc;

    rc = ata_pci_device_do_resume(pdev);
    if (rc == 0)
        ata_host_resume(host);
    return rc;
}
#endif /* CONFIG_PM */

#endif /* CONFIG_PCI */

static int __init ata_parse_force_one(char **cur,
                      struct ata_force_ent *force_ent,
                      const char **reason)
{
    /* FIXME: Currently, there's no way to tag init const data and
     * using __initdata causes build failure on some versions of
     * gcc.  Once __initdataconst is implemented, add const to the
     * following structure.
     */
    static struct ata_force_param force_tbl[] __initdata = {
        { "40c",    .cbl        = ATA_CBL_PATA40 },
        { "80c",    .cbl        = ATA_CBL_PATA80 },
        { "short40c",   .cbl        = ATA_CBL_PATA40_SHORT },
        { "unk",    .cbl        = ATA_CBL_PATA_UNK },
        { "ign",    .cbl        = ATA_CBL_PATA_IGN },
        { "sata",   .cbl        = ATA_CBL_SATA },
        { "1.5Gbps",    .spd_limit  = 1 },
        { "3.0Gbps",    .spd_limit  = 2 },
        { "noncq",  .horkage_on = ATA_HORKAGE_NONCQ },
        { "ncq",    .horkage_off    = ATA_HORKAGE_NONCQ },
        { "dump_id",    .horkage_on = ATA_HORKAGE_DUMP_ID },
        { "pio0",   .xfer_mask  = 1 << (ATA_SHIFT_PIO + 0) },
        { "pio1",   .xfer_mask  = 1 << (ATA_SHIFT_PIO + 1) },
        { "pio2",   .xfer_mask  = 1 << (ATA_SHIFT_PIO + 2) },
        { "pio3",   .xfer_mask  = 1 << (ATA_SHIFT_PIO + 3) },
        { "pio4",   .xfer_mask  = 1 << (ATA_SHIFT_PIO + 4) },
        { "pio5",   .xfer_mask  = 1 << (ATA_SHIFT_PIO + 5) },
        { "pio6",   .xfer_mask  = 1 << (ATA_SHIFT_PIO + 6) },
        { "mwdma0", .xfer_mask  = 1 << (ATA_SHIFT_MWDMA + 0) },
        { "mwdma1", .xfer_mask  = 1 << (ATA_SHIFT_MWDMA + 1) },
        { "mwdma2", .xfer_mask  = 1 << (ATA_SHIFT_MWDMA + 2) },
        { "mwdma3", .xfer_mask  = 1 << (ATA_SHIFT_MWDMA + 3) },
        { "mwdma4", .xfer_mask  = 1 << (ATA_SHIFT_MWDMA + 4) },
        { "udma0",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 0) },
        { "udma16", .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 0) },
        { "udma/16",    .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 0) },
        { "udma1",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 1) },
        { "udma25", .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 1) },
        { "udma/25",    .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 1) },
        { "udma2",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 2) },
        { "udma33", .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 2) },
        { "udma/33",    .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 2) },
        { "udma3",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 3) },
        { "udma44", .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 3) },
        { "udma/44",    .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 3) },
        { "udma4",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 4) },
        { "udma66", .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 4) },
        { "udma/66",    .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 4) },
        { "udma5",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 5) },
        { "udma100",    .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 5) },
        { "udma/100",   .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 5) },
        { "udma6",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 6) },
        { "udma133",    .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 6) },
        { "udma/133",   .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 6) },
        { "udma7",  .xfer_mask  = 1 << (ATA_SHIFT_UDMA + 7) },
        { "nohrst", .lflags     = ATA_LFLAG_NO_HRST },
        { "nosrst", .lflags     = ATA_LFLAG_NO_SRST },
        { "norst",  .lflags     = ATA_LFLAG_NO_HRST | ATA_LFLAG_NO_SRST },
        { "rstonce",    .lflags     = ATA_LFLAG_RST_ONCE },
    };
    char *start = *cur, *p = *cur;
    char *id, *val, *endp;
    const struct ata_force_param *match_fp = NULL;
    int nr_matches = 0, i;

    /* find where this param ends and update *cur */
    while (*p != '\0' && *p != ',')
        p++;

    if (*p == '\0')
        *cur = p;
    else
        *cur = p + 1;

    *p = '\0';

    /* parse */
    p = strchr(start, ':');
    if (!p) {
        val = strstrip(start);
        goto parse_val;
    }
    *p = '\0';

    id = strstrip(start);
    val = strstrip(p + 1);

    /* parse id */
    p = strchr(id, '.');
    if (p) {
        *p++ = '\0';
        force_ent->device = simple_strtoul(p, &endp, 10);
        if (p == endp || *endp != '\0') {
            *reason = "invalid device";
            return -EINVAL;
        }
    }

    force_ent->port = simple_strtoul(id, &endp, 10);
    if (p == endp || *endp != '\0') {
        *reason = "invalid port/link";
        return -EINVAL;
    }

 parse_val:
    /* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */
    for (i = 0; i < ARRAY_SIZE(force_tbl); i++) {
        const struct ata_force_param *fp = &force_tbl[i];

        if (strncasecmp(val, fp->name, strlen(val)))
            continue;

        nr_matches++;
        match_fp = fp;

        if (strcasecmp(val, fp->name) == 0) {
            nr_matches = 1;
            break;
        }
    }

    if (!nr_matches) {
        *reason = "unknown value";
        return -EINVAL;
    }
    if (nr_matches > 1) {
        *reason = "ambigious value";
        return -EINVAL;
    }

    force_ent->param = *match_fp;

    return 0;
}

static void __init ata_parse_force_param(void)
{
    int idx = 0, size = 1;
    int last_port = -1, last_device = -1;
    char *p, *cur, *next;

    /* calculate maximum number of params and allocate force_tbl */
    for (p = ata_force_param_buf; *p; p++)
        if (*p == ',')
            size++;

    ata_force_tbl = kzalloc(sizeof(ata_force_tbl[0]) * size, GFP_KERNEL);
    if (!ata_force_tbl) {
        printk(KERN_WARNING "ata: failed to extend force table, "
               "libata.force ignored\n");
        return;
    }

    /* parse and populate the table */
    for (cur = ata_force_param_buf; *cur != '\0'; cur = next) {
        const char *reason = "";
        struct ata_force_ent te = { .port = -1, .device = -1 };

        next = cur;
        if (ata_parse_force_one(&next, &te, &reason)) {
            printk(KERN_WARNING "ata: failed to parse force "
                   "parameter \"%s\" (%s)\n",
                   cur, reason);
            continue;
        }

        if (te.port == -1) {
            te.port = last_port;
            te.device = last_device;
        }

        ata_force_tbl[idx++] = te;

        last_port = te.port;
        last_device = te.device;
    }

    ata_force_tbl_size = idx;
}

static int __init ata_init(void)
{
    int rc;

    ata_parse_force_param();

    ata_acpi_register();

    rc = ata_sff_init();
    if (rc) {
        kfree(ata_force_tbl);
        return rc;
    }

    libata_transport_init();
    ata_scsi_transport_template = ata_attach_transport();
    if (!ata_scsi_transport_template) {
        ata_sff_exit();
        rc = -ENOMEM;
        goto err_out;
    }

    printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
    return 0;

err_out:
    return rc;
}

static void __exit ata_exit(void)
{
    ata_release_transport(ata_scsi_transport_template);
    libata_transport_exit();
    ata_sff_exit();
    ata_acpi_unregister();
    kfree(ata_force_tbl);
}

subsys_initcall(ata_init);
module_exit(ata_exit);

static DEFINE_RATELIMIT_STATE(ratelimit, HZ / 5, 1);

int ata_ratelimit(void)
{
    return __ratelimit(&ratelimit);
}

void ata_msleep(struct ata_port *ap, unsigned int msecs)
{
    bool owns_eh = ap && ap->host->eh_owner == current;

    if (owns_eh)
        ata_eh_release(ap);

    msleep(msecs);

    if (owns_eh)
        ata_eh_acquire(ap);
}

u32 ata_wait_register(struct ata_port *ap, void __iomem *reg, u32 mask, u32 val,
              unsigned long interval, unsigned long timeout)
{
    unsigned long deadline;
    u32 tmp;

    tmp = ioread32(reg);

    /* Calculate timeout _after_ the first read to make sure
     * preceding writes reach the controller before starting to
     * eat away the timeout.
     */
    deadline = ata_deadline(jiffies, timeout);

    while ((tmp & mask) == val && time_before(jiffies, deadline)) {
        ata_msleep(ap, interval);
        tmp = ioread32(reg);
    }

    return tmp;
}

/*
 * Dummy port_ops
 */
static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
{
    return AC_ERR_SYSTEM;
}

static void ata_dummy_error_handler(struct ata_port *ap)
{
    /* truly dummy */
}

struct ata_port_operations ata_dummy_port_ops = {
    .qc_prep        = ata_noop_qc_prep,
    .qc_issue       = ata_dummy_qc_issue,
    .error_handler      = ata_dummy_error_handler,
    .sched_eh       = ata_std_sched_eh,
    .end_eh         = ata_std_end_eh,
};

const struct ata_port_info ata_dummy_port_info = {
    .port_ops       = &ata_dummy_port_ops,
};

/*
 * Utility print functions
 */
int ata_port_printk(const struct ata_port *ap, const char *level,
            const char *fmt, ...)
{
    struct va_format vaf;
    va_list args;
    int r;

    va_start(args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    r = printk("%sata%u: %pV", level, ap->print_id, &vaf);

    va_end(args);

    return r;
}
EXPORT_SYMBOL(ata_port_printk);

int ata_link_printk(const struct ata_link *link, const char *level,
            const char *fmt, ...)
{
    struct va_format vaf;
    va_list args;
    int r;

    va_start(args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    if (sata_pmp_attached(link->ap) || link->ap->slave_link)
        r = printk("%sata%u.%02u: %pV",
               level, link->ap->print_id, link->pmp, &vaf);
    else
        r = printk("%sata%u: %pV",
               level, link->ap->print_id, &vaf);

    va_end(args);

    return r;
}
EXPORT_SYMBOL(ata_link_printk);

int ata_dev_printk(const struct ata_device *dev, const char *level,
            const char *fmt, ...)
{
    struct va_format vaf;
    va_list args;
    int r;

    va_start(args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    r = printk("%sata%u.%02u: %pV",
           level, dev->link->ap->print_id, dev->link->pmp + dev->devno,
           &vaf);

    va_end(args);

    return r;
}
EXPORT_SYMBOL(ata_dev_printk);

void ata_print_version(const struct device *dev, const char *version)
{
    dev_printk(KERN_DEBUG, dev, "version %s\n", version);
}
EXPORT_SYMBOL(ata_print_version);

/*
 * libata is essentially a library of internal helper functions for
 * low-level ATA host controller drivers.  As such, the API/ABI is
 * likely to change as new drivers are added and updated.
 * Do not depend on ABI/API stability.
 */
EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
EXPORT_SYMBOL_GPL(sata_deb_timing_long);
EXPORT_SYMBOL_GPL(ata_base_port_ops);
EXPORT_SYMBOL_GPL(sata_port_ops);
EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
EXPORT_SYMBOL_GPL(ata_dummy_port_info);
EXPORT_SYMBOL_GPL(ata_link_next);
EXPORT_SYMBOL_GPL(ata_dev_next);
EXPORT_SYMBOL_GPL(ata_std_bios_param);
EXPORT_SYMBOL_GPL(ata_scsi_unlock_native_capacity);
EXPORT_SYMBOL_GPL(ata_host_init);
EXPORT_SYMBOL_GPL(ata_host_alloc);
EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
EXPORT_SYMBOL_GPL(ata_slave_link_init);
EXPORT_SYMBOL_GPL(ata_host_start);
EXPORT_SYMBOL_GPL(ata_host_register);
EXPORT_SYMBOL_GPL(ata_host_activate);
EXPORT_SYMBOL_GPL(ata_host_detach);
EXPORT_SYMBOL_GPL(ata_sg_init);
EXPORT_SYMBOL_GPL(ata_qc_complete);
EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
EXPORT_SYMBOL_GPL(atapi_cmd_type);
EXPORT_SYMBOL_GPL(ata_tf_to_fis);
EXPORT_SYMBOL_GPL(ata_tf_from_fis);
EXPORT_SYMBOL_GPL(ata_pack_xfermask);
EXPORT_SYMBOL_GPL(ata_unpack_xfermask);
EXPORT_SYMBOL_GPL(ata_xfer_mask2mode);
EXPORT_SYMBOL_GPL(ata_xfer_mode2mask);
EXPORT_SYMBOL_GPL(ata_xfer_mode2shift);
EXPORT_SYMBOL_GPL(ata_mode_string);
EXPORT_SYMBOL_GPL(ata_id_xfermask);
EXPORT_SYMBOL_GPL(ata_do_set_mode);
EXPORT_SYMBOL_GPL(ata_std_qc_defer);
EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
EXPORT_SYMBOL_GPL(ata_dev_disable);
EXPORT_SYMBOL_GPL(sata_set_spd);
EXPORT_SYMBOL_GPL(ata_wait_after_reset);
EXPORT_SYMBOL_GPL(sata_link_debounce);
EXPORT_SYMBOL_GPL(sata_link_resume);
EXPORT_SYMBOL_GPL(sata_link_scr_lpm);
EXPORT_SYMBOL_GPL(ata_std_prereset);
EXPORT_SYMBOL_GPL(sata_link_hardreset);
EXPORT_SYMBOL_GPL(sata_std_hardreset);
EXPORT_SYMBOL_GPL(ata_std_postreset);
EXPORT_SYMBOL_GPL(ata_dev_classify);
EXPORT_SYMBOL_GPL(ata_dev_pair);
EXPORT_SYMBOL_GPL(ata_ratelimit);
EXPORT_SYMBOL_GPL(ata_msleep);
EXPORT_SYMBOL_GPL(ata_wait_register);
EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
EXPORT_SYMBOL_GPL(__ata_change_queue_depth);
EXPORT_SYMBOL_GPL(sata_scr_valid);
EXPORT_SYMBOL_GPL(sata_scr_read);
EXPORT_SYMBOL_GPL(sata_scr_write);
EXPORT_SYMBOL_GPL(sata_scr_write_flush);
EXPORT_SYMBOL_GPL(ata_link_online);
EXPORT_SYMBOL_GPL(ata_link_offline);
#ifdef CONFIG_PM
EXPORT_SYMBOL_GPL(ata_host_suspend);
EXPORT_SYMBOL_GPL(ata_host_resume);
#endif /* CONFIG_PM */
EXPORT_SYMBOL_GPL(ata_id_string);
EXPORT_SYMBOL_GPL(ata_id_c_string);
EXPORT_SYMBOL_GPL(ata_do_dev_read_id);
EXPORT_SYMBOL_GPL(ata_scsi_simulate);

EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
EXPORT_SYMBOL_GPL(ata_timing_find_mode);
EXPORT_SYMBOL_GPL(ata_timing_compute);
EXPORT_SYMBOL_GPL(ata_timing_merge);
EXPORT_SYMBOL_GPL(ata_timing_cycle2mode);

#ifdef CONFIG_PCI
EXPORT_SYMBOL_GPL(pci_test_config_bits);
EXPORT_SYMBOL_GPL(ata_pci_remove_one);
#ifdef CONFIG_PM
EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
EXPORT_SYMBOL_GPL(ata_pci_device_resume);
#endif /* CONFIG_PM */
#endif /* CONFIG_PCI */

EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);
EXPORT_SYMBOL_GPL(ata_port_desc);
#ifdef CONFIG_PCI
EXPORT_SYMBOL_GPL(ata_port_pbar_desc);
#endif /* CONFIG_PCI */
EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
EXPORT_SYMBOL_GPL(ata_link_abort);
EXPORT_SYMBOL_GPL(ata_port_abort);
EXPORT_SYMBOL_GPL(ata_port_freeze);
EXPORT_SYMBOL_GPL(sata_async_notification);
EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
EXPORT_SYMBOL_GPL(ata_eh_analyze_ncq_error);
EXPORT_SYMBOL_GPL(ata_do_eh);
EXPORT_SYMBOL_GPL(ata_std_error_handler);

EXPORT_SYMBOL_GPL(ata_cable_40wire);
EXPORT_SYMBOL_GPL(ata_cable_80wire);
EXPORT_SYMBOL_GPL(ata_cable_unknown);
EXPORT_SYMBOL_GPL(ata_cable_ignore);
EXPORT_SYMBOL_GPL(ata_cable_sata);