text: /*
   *  libata-core.c - helper library for ATA
   *
   *  Maintained by:  Tejun Heo <tj@kernel.org>
   *    		    Please ALWAYS copy linux-ide@vger.kernel.org
   *		    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 <linux/glob.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 <linux/platform_device.h>
  
  #define CREATE_TRACE_POINTS
  #include <trace/events/libata.h>
  
  #include "libata.h"
  #include "libata-transport.h"
  
  /* debounce timing parameters in msecs { interval, duration, timeout } */
  const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
  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;
  }
  
  /**
   *	ata_link_next - link iteration helper
   *	@link: the previous link, NULL to start
   *	@ap: ATA port containing links to iterate
   *	@mode: iteration mode, one of ATA_LITER_*
   *
   *	LOCKING:
   *	Host lock or EH context.
   *
   *	RETURNS:
   *	Pointer to the next link.
   */
  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;
  }
  
  /**
   *	ata_dev_next - device iteration helper
   *	@dev: the previous device, NULL to start
   *	@link: ATA link containing devices to iterate
   *	@mode: iteration mode, one of ATA_DITER_*
   *
   *	LOCKING:
   *	Host lock or EH context.
   *
   *	RETURNS:
   *	Pointer to the next device.
   */
  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;
  }
  
  /**
   *	ata_dev_phys_link - find physical link for a device
   *	@dev: ATA device to look up physical link for
   *
   *	Look up physical link which @dev is attached to.  Note that
   *	this is different from @dev->link only when @dev is on slave
   *	link.  For all other cases, it's the same as @dev->link.
   *
   *	LOCKING:
   *	Don't care.
   *
   *	RETURNS:
   *	Pointer to the found physical link.
   */
  struct ata_link *ata_dev_phys_link(struct ata_device *dev)
  {
  	struct ata_port *ap = dev->link->ap;
  
  	if (!ap->slave_link)
  		return dev->link;
  	if (!dev->devno)
  		return &ap->link;
  	return ap->slave_link;
  }
  
  /**
   *	ata_force_cbl - force cable type according to libata.force
   *	@ap: ATA port of interest
   *
   *	Force cable type according to libata.force and whine about it.
   *	The last entry which has matching port number is used, so it
   *	can be specified as part of device force parameters.  For
   *	example, both "a:40c,1.00:udma4" and "1.00:40c,udma4" have the
   *	same effect.
   *
   *	LOCKING:
   *	EH context.
   */
  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;
  	}
  }
  
  /**
   *	ata_force_link_limits - force link limits according to libata.force
   *	@link: ATA link of interest
   *
   *	Force link flags and SATA spd limit according to libata.force
   *	and whine about it.  When only the port part is specified
   *	(e.g. 1:), the limit applies to all links connected to both
   *	the host link and all fan-out ports connected via PMP.  If the
   *	device part is specified as 0 (e.g. 1.00:), it specifies the
   *	first fan-out link not the host link.  Device number 15 always
   *	points to the host link whether PMP is attached or not.  If the
   *	controller has slave link, device number 16 points to it.
   *
   *	LOCKING:
   *	EH context.
   */
  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);
  		}
  	}
  }
  
  /**
   *	ata_force_xfermask - force xfermask according to libata.force
   *	@dev: ATA device of interest
   *
   *	Force xfer_mask according to libata.force and whine about it.
   *	For consistency with link selection, device number 15 selects
   *	the first device connected to the host link.
   *
   *	LOCKING:
   *	EH context.
   */
  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;
  	}
  }
  
  /**
   *	ata_force_horkage - force horkage according to libata.force
   *	@dev: ATA device of interest
   *
   *	Force horkage according to libata.force and whine about it.
   *	For consistency with link selection, device number 15 selects
   *	the first device connected to the host link.
   *
   *	LOCKING:
   *	EH context.
   */
  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);
  	}
  }
  
  /**
   *	atapi_cmd_type - Determine ATAPI command type from SCSI opcode
   *	@opcode: SCSI opcode
   *
   *	Determine ATAPI command type from @opcode.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	ATAPI_{READ|WRITE|READ_CD|PASS_THRU|MISC}
   */
  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;
  	}
  }
  
  /**
   *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
   *	@tf: Taskfile to convert
   *	@pmp: Port multiplier port
   *	@is_cmd: This FIS is for command
   *	@fis: Buffer into which data will output
   *
   *	Converts a standard ATA taskfile to a Serial ATA
   *	FIS structure (Register - Host to Device).
   *
   *	LOCKING:
   *	Inherited from caller.
   */
  void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
  {
  	fis[0] = 0x27;			/* Register - Host to Device FIS */
  	fis[1] = pmp & 0xf;		/* Port multiplier number*/
  	if (is_cmd)
  		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
  
  	fis[2] = tf->command;
  	fis[3] = tf->feature;
  
  	fis[4] = tf->lbal;
  	fis[5] = tf->lbam;
  	fis[6] = tf->lbah;
  	fis[7] = tf->device;
  
  	fis[8] = tf->hob_lbal;
  	fis[9] = tf->hob_lbam;
  	fis[10] = tf->hob_lbah;
  	fis[11] = tf->hob_feature;
  
  	fis[12] = tf->nsect;
  	fis[13] = tf->hob_nsect;
  	fis[14] = 0;
  	fis[15] = tf->ctl;
  
  	fis[16] = tf->auxiliary & 0xff;
  	fis[17] = (tf->auxiliary >> 8) & 0xff;
  	fis[18] = (tf->auxiliary >> 16) & 0xff;
  	fis[19] = (tf->auxiliary >> 24) & 0xff;
  }
  
  /**
   *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
   *	@fis: Buffer from which data will be input
   *	@tf: Taskfile to output
   *
   *	Converts a serial ATA FIS structure to a standard ATA taskfile.
   *
   *	LOCKING:
   *	Inherited from caller.
   */
  
  void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
  {
  	tf->command	= fis[2];	/* status */
  	tf->feature	= fis[3];	/* error */
  
  	tf->lbal	= fis[4];
  	tf->lbam	= fis[5];
  	tf->lbah	= fis[6];
  	tf->device	= fis[7];
  
  	tf->hob_lbal	= fis[8];
  	tf->hob_lbam	= fis[9];
  	tf->hob_lbah	= fis[10];
  
  	tf->nsect	= fis[12];
  	tf->hob_nsect	= fis[13];
  }
  
  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
  };
  
  /**
   *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
   *	@tf: command to examine and configure
   *	@dev: device tf belongs to
   *
   *	Examine the device configuration and tf->flags to calculate
   *	the proper read/write commands and protocol to use.
   *
   *	LOCKING:
   *	caller.
   */
  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;
  }
  
  /**
   *	ata_tf_read_block - Read block address from ATA taskfile
   *	@tf: ATA taskfile of interest
   *	@dev: ATA device @tf belongs to
   *
   *	LOCKING:
   *	None.
   *
   *	Read block address from @tf.  This function can handle all
   *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
   *	flags select the address format to use.
   *
   *	RETURNS:
   *	Block address read from @tf.
   */
  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;
  }
  
  /**
   *	ata_build_rw_tf - Build ATA taskfile for given read/write request
   *	@tf: Target ATA taskfile
   *	@dev: ATA device @tf belongs to
   *	@block: Block address
   *	@n_block: Number of blocks
   *	@tf_flags: RW/FUA etc...
   *	@tag: tag
   *
   *	LOCKING:
   *	None.
   *
   *	Build ATA taskfile @tf for read/write request described by
   *	@block, @n_block, @tf_flags and @tag on @dev.
   *
   *	RETURNS:
   *
   *	0 on success, -ERANGE if the request is too large for @dev,
   *	-EINVAL if the request is invalid.
   */
  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;
  }
  
  /**
   *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
   *	@pio_mask: pio_mask
   *	@mwdma_mask: mwdma_mask
   *	@udma_mask: udma_mask
   *
   *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
   *	unsigned int xfer_mask.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Packed xfer_mask.
   */
  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);
  }
  
  /**
   *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
   *	@xfer_mask: xfer_mask to unpack
   *	@pio_mask: resulting pio_mask
   *	@mwdma_mask: resulting mwdma_mask
   *	@udma_mask: resulting udma_mask
   *
   *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
   *	Any NULL distination masks will be ignored.
   */
  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, },
  };
  
  /**
   *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
   *	@xfer_mask: xfer_mask of interest
   *
   *	Return matching XFER_* value for @xfer_mask.  Only the highest
   *	bit of @xfer_mask is considered.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Matching XFER_* value, 0xff if no match found.
   */
  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;
  }
  
  /**
   *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
   *	@xfer_mode: XFER_* of interest
   *
   *	Return matching xfer_mask for @xfer_mode.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Matching xfer_mask, 0 if no match found.
   */
  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;
  }
  
  /**
   *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
   *	@xfer_mode: XFER_* of interest
   *
   *	Return matching xfer_shift for @xfer_mode.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Matching xfer_shift, -1 if no match found.
   */
  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;
  }
  
  /**
   *	ata_mode_string - convert xfer_mask to string
   *	@xfer_mask: mask of bits supported; only highest bit counts.
   *
   *	Determine string which represents the highest speed
   *	(highest bit in @modemask).
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Constant C string representing highest speed listed in
   *	@mode_mask, or the constant C string "<n/a>".
   */
  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];
  }
  
  /**
   *	ata_dev_classify - determine device type based on ATA-spec signature
   *	@tf: ATA taskfile register set for device to be identified
   *
   *	Determine from taskfile register contents whether a device is
   *	ATA or ATAPI, as per "Signature and persistence" section
   *	of ATA/PI spec (volume 1, sect 5.14).
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP,
   *	%ATA_DEV_ZAC, or %ATA_DEV_UNKNOWN the event of failure.
   */
  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;
  	}
  
  	if ((tf->lbam == 0xcd) && (tf->lbah == 0xab)) {
  		DPRINTK("found ZAC device by sig\n");
  		return ATA_DEV_ZAC;
  	}
  
  	DPRINTK("unknown device\n");
  	return ATA_DEV_UNKNOWN;
  }
  
  /**
   *	ata_id_string - Convert IDENTIFY DEVICE page into string
   *	@id: IDENTIFY DEVICE results we will examine
   *	@s: string into which data is output
   *	@ofs: offset into identify device page
   *	@len: length of string to return. must be an even number.
   *
   *	The strings in the IDENTIFY DEVICE page are broken up into
   *	16-bit chunks.  Run through the string, and output each
   *	8-bit chunk linearly, regardless of platform.
   *
   *	LOCKING:
   *	caller.
   */
  
  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;
  	}
  }
  
  /**
   *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
   *	@id: IDENTIFY DEVICE results we will examine
   *	@s: string into which data is output
   *	@ofs: offset into identify device page
   *	@len: length of string to return. must be an odd number.
   *
   *	This function is identical to ata_id_string except that it
   *	trims trailing spaces and terminates the resulting string with
   *	null.  @len must be actual maximum length (even number) + 1.
   *
   *	LOCKING:
   *	caller.
   */
  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;
  }
  
  /**
   *	ata_read_native_max_address - Read native max address
   *	@dev: target device
   *	@max_sectors: out parameter for the result native max address
   *
   *	Perform an LBA48 or LBA28 native size query upon the device in
   *	question.
   *
   *	RETURNS:
   *	0 on success, -EACCES if command is aborted by the drive.
   *	-EIO on other errors.
   */
  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;
  }
  
  /**
   *	ata_set_max_sectors - Set max sectors
   *	@dev: target device
   *	@new_sectors: new max sectors value to set for the device
   *
   *	Set max sectors of @dev to @new_sectors.
   *
   *	RETURNS:
   *	0 on success, -EACCES if command is aborted or denied (due to
   *	previous non-volatile SET_MAX) by the drive.  -EIO on other
   *	errors.
   */
  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;
  }
  
  /**
   *	ata_hpa_resize		-	Resize a device with an HPA set
   *	@dev: Device to resize
   *
   *	Read the size of an LBA28 or LBA48 disk with HPA features and resize
   *	it if required to the full size of the media. The caller must check
   *	the drive has the HPA feature set enabled.
   *
   *	RETURNS:
   *	0 on success, -errno on failure.
   */
  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 && dev->class != ATA_DEV_ZAC) ||
  	    !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;
  }
  
  /**
   *	ata_dump_id - IDENTIFY DEVICE info debugging output
   *	@id: IDENTIFY DEVICE page to dump
   *
   *	Dump selected 16-bit words from the given IDENTIFY DEVICE
   *	page.
   *
   *	LOCKING:
   *	caller.
   */
  
  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]);
  }
  
  /**
   *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
   *	@id: IDENTIFY data to compute xfer mask from
   *
   *	Compute the xfermask for this device. This is not as trivial
   *	as it seems if we must consider early devices correctly.
   *
   *	FIXME: pre IDE drive timing (do we care ?).
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Computed xfermask
   */
  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);
  }
  
  /**
   *	ata_exec_internal_sg - execute libata internal command
   *	@dev: Device to which the command is sent
   *	@tf: Taskfile registers for the command and the result
   *	@cdb: CDB for packet command
   *	@dma_dir: Data transfer direction of the command
   *	@sgl: sg list for the data buffer of the command
   *	@n_elem: Number of sg entries
   *	@timeout: Timeout in msecs (0 for default)
   *
   *	Executes libata internal command with timeout.  @tf contains
   *	command on entry and result on return.  Timeout and error
   *	conditions are reported via return value.  No recovery action
   *	is taken after a command times out.  It's caller's duty to
   *	clean up after timeout.
   *
   *	LOCKING:
   *	None.  Should be called with kernel context, might sleep.
   *
   *	RETURNS:
   *	Zero on success, AC_ERR_* mask on failure
   */
  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;
  
  	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);
  
  	/* some SATA bridges need us to indicate data xfer direction */
  	if (tf->protocol == ATAPI_PROT_DMA && (dev->flags & ATA_DFLAG_DMADIR) &&
  	    dma_dir == DMA_FROM_DEVICE)
  		qc->tf.feature |= ATAPI_DMADIR;
  
  	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;
  }
  
  /**
   *	ata_exec_internal - execute libata internal command
   *	@dev: Device to which the command is sent
   *	@tf: Taskfile registers for the command and the result
   *	@cdb: CDB for packet command
   *	@dma_dir: Data transfer direction of the command
   *	@buf: Data buffer of the command
   *	@buflen: Length of data buffer
   *	@timeout: Timeout in msecs (0 for default)
   *
   *	Wrapper around ata_exec_internal_sg() which takes simple
   *	buffer instead of sg list.
   *
   *	LOCKING:
   *	None.  Should be called with kernel context, might sleep.
   *
   *	RETURNS:
   *	Zero on success, AC_ERR_* mask on failure
   */
  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);
  }
  
  /**
   *	ata_pio_need_iordy	-	check if iordy needed
   *	@adev: ATA device
   *
   *	Check if the current speed of the device requires IORDY. Used
   *	by various controllers for chip configuration.
   */
  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;
  }
  
  /**
   *	ata_pio_mask_no_iordy	-	Return the non IORDY mask
   *	@adev: ATA device
   *
   *	Compute the highest mode possible if we are not using iordy. Return
   *	-1 if no iordy mode is available.
   */
  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;
  }
  
  /**
   *	ata_do_dev_read_id		-	default ID read method
   *	@dev: device
   *	@tf: proposed taskfile
   *	@id: data buffer
   *
   *	Issue the identify taskfile and hand back the buffer containing
   *	identify data. For some RAID controllers and for pre ATA devices
   *	this function is wrapped or replaced by the driver
   */
  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);
  }
  
  /**
   *	ata_dev_read_id - Read ID data from the specified device
   *	@dev: target device
   *	@p_class: pointer to class of the target device (may be changed)
   *	@flags: ATA_READID_* flags
   *	@id: buffer to read IDENTIFY data into
   *
   *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
   *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
   *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
   *	for pre-ATA4 drives.
   *
   *	FIXME: ATA_CMD_ID_ATA is optional for early drives and right
   *	now we abort if we hit that case.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, -errno otherwise.
   */
  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:
  	case ATA_DEV_ZAC:
  		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 || class == ATA_DEV_ZAC) {
  		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 || class == ATA_DEV_ZAC)) {
  		/*
  		 * 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);
  
  	if ((ap->flags & ATA_FLAG_FPDMA_AUX) &&
  	    ata_id_has_ncq_send_and_recv(dev->id)) {
  		err_mask = ata_read_log_page(dev, ATA_LOG_NCQ_SEND_RECV,
  					     0, ap->sector_buf, 1);
  		if (err_mask) {
  			ata_dev_dbg(dev,
  				    "failed to get NCQ Send/Recv Log Emask 0x%x\n",
  				    err_mask);
  		} else {
  			u8 *cmds = dev->ncq_send_recv_cmds;
  
  			dev->flags |= ATA_DFLAG_NCQ_SEND_RECV;
  			memcpy(cmds, ap->sector_buf, ATA_LOG_NCQ_SEND_RECV_SIZE);
  
  			if (dev->horkage & ATA_HORKAGE_NO_NCQ_TRIM) {
  				ata_dev_dbg(dev, "disabling queued TRIM support\n");
  				cmds[ATA_LOG_NCQ_SEND_RECV_DSM_OFFSET] &=
  					~ATA_LOG_NCQ_SEND_RECV_DSM_TRIM;
  			}
  		}
  	}
  
  	return 0;
  }
  
  /**
   *	ata_dev_configure - Configure the specified ATA/ATAPI device
   *	@dev: Target device to configure
   *
   *	Configure @dev according to @dev->id.  Generic and low-level
   *	driver specific fixups are also applied.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, -errno otherwise
   */
  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;
  
  	/* some WD SATA-1 drives have issues with LPM, turn on NOLPM for them */
  	if ((dev->horkage & ATA_HORKAGE_WD_BROKEN_LPM) &&
  	    (id[ATA_ID_SATA_CAPABILITY] & 0xe) == 0x2)
  		dev->horkage |= ATA_HORKAGE_NOLPM;
  
  	if (dev->horkage & ATA_HORKAGE_NOLPM) {
  		ata_dev_warn(dev, "LPM support broken, forcing max_power\n");
  		dev->link->ap->target_lpm_policy = ATA_LPM_MAX_POWER;
  	}
  
  	/* 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 || dev->class == ATA_DEV_ZAC) {
  		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. Get DevSlp timing variables
  		 * from SATA Settings page of Identify Device Data Log.
  		 */
  		if (ata_id_has_devslp(dev->id)) {
  			u8 *sata_setting = ap->sector_buf;
  			int i, j;
  
  			dev->flags |= ATA_DFLAG_DEVSLP;
  			err_mask = ata_read_log_page(dev,
  						     ATA_LOG_SATA_ID_DEV_DATA,
  						     ATA_LOG_SATA_SETTINGS,
  						     sata_setting,
  						     1);
  			if (err_mask)
  				ata_dev_dbg(dev,
  					    "failed to get Identify Device Data, Emask 0x%x\n",
  					    err_mask);
  			else
  				for (i = 0; i < ATA_LOG_DEVSLP_SIZE; i++) {
  					j = ATA_LOG_DEVSLP_OFFSET + i;
  					dev->devslp_timing[i] = sata_setting[j];
  				}
  		}
  
  		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 || (dev->horkage & ATA_HORKAGE_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;
  			zpodd_init(dev);
  		}
  
  		/* 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 (dev->horkage & ATA_HORKAGE_MAX_SEC_1024)
  		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_1024,
  					 dev->max_sectors);
  
  	if (dev->horkage & ATA_HORKAGE_MAX_SEC_LBA48)
  		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
  
  	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;
  }
  
  /**
   *	ata_cable_40wire	-	return 40 wire cable type
   *	@ap: port
   *
   *	Helper method for drivers which want to hardwire 40 wire cable
   *	detection.
   */
  
  int ata_cable_40wire(struct ata_port *ap)
  {
  	return ATA_CBL_PATA40;
  }
  
  /**
   *	ata_cable_80wire	-	return 80 wire cable type
   *	@ap: port
   *
   *	Helper method for drivers which want to hardwire 80 wire cable
   *	detection.
   */
  
  int ata_cable_80wire(struct ata_port *ap)
  {
  	return ATA_CBL_PATA80;
  }
  
  /**
   *	ata_cable_unknown	-	return unknown PATA cable.
   *	@ap: port
   *
   *	Helper method for drivers which have no PATA cable detection.
   */
  
  int ata_cable_unknown(struct ata_port *ap)
  {
  	return ATA_CBL_PATA_UNK;
  }
  
  /**
   *	ata_cable_ignore	-	return ignored PATA cable.
   *	@ap: port
   *
   *	Helper method for drivers which don't use cable type to limit
   *	transfer mode.
   */
  int ata_cable_ignore(struct ata_port *ap)
  {
  	return ATA_CBL_PATA_IGN;
  }
  
  /**
   *	ata_cable_sata	-	return SATA cable type
   *	@ap: port
   *
   *	Helper method for drivers which have SATA cables
   */
  
  int ata_cable_sata(struct ata_port *ap)
  {
  	return ATA_CBL_SATA;
  }
  
  /**
   *	ata_bus_probe - Reset and probe ATA bus
   *	@ap: Bus to probe
   *
   *	Master ATA bus probing function.  Initiates a hardware-dependent
   *	bus reset, then attempts to identify any devices found on
   *	the bus.
   *
   *	LOCKING:
   *	PCI/etc. bus probe sem.
   *
   *	RETURNS:
   *	Zero on success, negative errno otherwise.
   */
  
  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;
  		dev->dma_mode = 0xff;
  
  		/* 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;
  }
  
  /**
   *	sata_print_link_status - Print SATA link status
   *	@link: SATA link to printk link status about
   *
   *	This function prints link speed and status of a SATA link.
   *
   *	LOCKING:
   *	None.
   */
  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);
  	}
  }
  
  /**
   *	ata_dev_pair		-	return other device on cable
   *	@adev: device
   *
   *	Obtain the other device on the same cable, or if none is
   *	present NULL is returned
   */
  
  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;
  }
  
  /**
   *	sata_down_spd_limit - adjust SATA spd limit downward
   *	@link: Link to adjust SATA spd limit for
   *	@spd_limit: Additional limit
   *
   *	Adjust SATA spd limit of @link downward.  Note that this
   *	function only adjusts the limit.  The change must be applied
   *	using sata_set_spd().
   *
   *	If @spd_limit is non-zero, the speed is limited to equal to or
   *	lower than @spd_limit if such speed is supported.  If
   *	@spd_limit is slower than any supported speed, only the lowest
   *	supported speed is allowed.
   *
   *	LOCKING:
   *	Inherited from caller.
   *
   *	RETURNS:
   *	0 on success, negative errno on failure
   */
  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;
  }
  
  /**
   *	sata_set_spd_needed - is SATA spd configuration needed
   *	@link: Link in question
   *
   *	Test whether the spd limit in SControl matches
   *	@link->sata_spd_limit.  This function is used to determine
   *	whether hardreset is necessary to apply SATA spd
   *	configuration.
   *
   *	LOCKING:
   *	Inherited from caller.
   *
   *	RETURNS:
   *	1 if SATA spd configuration is needed, 0 otherwise.
   */
  static int sata_set_spd_needed(struct ata_link *link)
  {
  	u32 scontrol;
  
  	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
  		return 1;
  
  	return __sata_set_spd_needed(link, &scontrol);
  }
  
  /**
   *	sata_set_spd - set SATA spd according to spd limit
   *	@link: Link to set SATA spd for
   *
   *	Set SATA spd of @link according to sata_spd_limit.
   *
   *	LOCKING:
   *	Inherited from caller.
   *
   *	RETURNS:
   *	0 if spd doesn't need to be changed, 1 if spd has been
   *	changed.  Negative errno if SCR registers are inaccessible.
   */
  int sata_set_spd(struct ata_link *link)
  {
  	u32 scontrol;
  	int rc;
  
  	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
  		return rc;
  
  	if (!__sata_set_spd_needed(link, &scontrol))
  		return 0;
  
  	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
  		return rc;
  
  	return 1;
  }
  
  /*
   * 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;
  }
  
  /**
   *	ata_timing_cycle2mode - find xfer mode for the specified cycle duration
   *	@xfer_shift: ATA_SHIFT_* value for transfer type to examine.
   *	@cycle: cycle duration in ns
   *
   *	Return matching xfer mode for @cycle.  The returned mode is of
   *	the transfer type specified by @xfer_shift.  If @cycle is too
   *	slow for @xfer_shift, 0xff is returned.  If @cycle is faster
   *	than the fastest known mode, the fasted mode is returned.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	Matching xfer_mode, 0xff if no match found.
   */
  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;
  }
  
  /**
   *	ata_down_xfermask_limit - adjust dev xfer masks downward
   *	@dev: Device to adjust xfer masks
   *	@sel: ATA_DNXFER_* selector
   *
   *	Adjust xfer masks of @dev downward.  Note that this function
   *	does not apply the change.  Invoking ata_set_mode() afterwards
   *	will apply the limit.
   *
   *	LOCKING:
   *	Inherited from caller.
   *
   *	RETURNS:
   *	0 on success, negative errno on failure
   */
  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;
  }
  
  /**
   *	ata_do_set_mode - Program timings and issue SET FEATURES - XFER
   *	@link: link on which timings will be programmed
   *	@r_failed_dev: out parameter for failed device
   *
   *	Standard implementation of the function used to tune and set
   *	ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
   *	ata_dev_set_mode() fails, pointer to the failing device is
   *	returned in @r_failed_dev.
   *
   *	LOCKING:
   *	PCI/etc. bus probe sem.
   *
   *	RETURNS:
   *	0 on success, negative errno otherwise
   */
  
  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;
  }
  
  /**
   *	ata_wait_ready - wait for link to become ready
   *	@link: link to be waited on
   *	@deadline: deadline jiffies for the operation
   *	@check_ready: callback to check link readiness
   *
   *	Wait for @link to become ready.  @check_ready should return
   *	positive number if @link is ready, 0 if it isn't, -ENODEV if
   *	link doesn't seem to be occupied, other errno for other error
   *	conditions.
   *
   *	Transient -ENODEV conditions are allowed for
   *	ATA_TMOUT_FF_WAIT.
   *
   *	LOCKING:
   *	EH context.
   *
   *	RETURNS:
   *	0 if @linke is ready before @deadline; otherwise, -errno.
   */
  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);
  	}
  }
  
  /**
   *	ata_wait_after_reset - wait for link to become ready after reset
   *	@link: link to be waited on
   *	@deadline: deadline jiffies for the operation
   *	@check_ready: callback to check link readiness
   *
   *	Wait for @link to become ready after reset.
   *
   *	LOCKING:
   *	EH context.
   *
   *	RETURNS:
   *	0 if @linke is ready before @deadline; otherwise, -errno.
   */
  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);
  }
  
  /**
   *	sata_link_debounce - debounce SATA phy status
   *	@link: ATA link to debounce SATA phy status for
   *	@params: timing parameters { interval, duratinon, timeout } in msec
   *	@deadline: deadline jiffies for the operation
   *
   *	Make sure SStatus of @link reaches stable state, determined by
   *	holding the same value where DET is not 1 for @duration polled
   *	every @interval, before @timeout.  Timeout constraints the
   *	beginning of the stable state.  Because DET gets stuck at 1 on
   *	some controllers after hot unplugging, this functions waits
   *	until timeout then returns 0 if DET is stable at 1.
   *
   *	@timeout is further limited by @deadline.  The sooner of the
   *	two is used.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, -errno on failure.
   */
  int sata_link_debounce(struct ata_link *link, const unsigned long *params,
  		       unsigned long deadline)
  {
  	unsigned long interval = params[0];
  	unsigned long duration = params[1];
  	unsigned long last_jiffies, t;
  	u32 last, cur;
  	int rc;
  
  	t = ata_deadline(jiffies, params[2]);
  	if (time_before(t, deadline))
  		deadline = t;
  
  	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
  		return rc;
  	cur &= 0xf;
  
  	last = cur;
  	last_jiffies = jiffies;
  
  	while (1) {
  		ata_msleep(link->ap, interval);
  		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
  			return rc;
  		cur &= 0xf;
  
  		/* DET stable? */
  		if (cur == last) {
  			if (cur == 1 && time_before(jiffies, deadline))
  				continue;
  			if (time_after(jiffies,
  				       ata_deadline(last_jiffies, duration)))
  				return 0;
  			continue;
  		}
  
  		/* unstable, start over */
  		last = cur;
  		last_jiffies = jiffies;
  
  		/* Check deadline.  If debouncing failed, return
  		 * -EPIPE to tell upper layer to lower link speed.
  		 */
  		if (time_after(jiffies, deadline))
  			return -EPIPE;
  	}
  }
  
  /**
   *	sata_link_resume - resume SATA link
   *	@link: ATA link to resume SATA
   *	@params: timing parameters { interval, duratinon, timeout } in msec
   *	@deadline: deadline jiffies for the operation
   *
   *	Resume SATA phy @link and debounce it.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, -errno on failure.
   */
  int sata_link_resume(struct ata_link *link, const unsigned long *params,
  		     unsigned long deadline)
  {
  	int tries = ATA_LINK_RESUME_TRIES;
  	u32 scontrol, serror;
  	int rc;
  
  	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
  		return rc;
  
  	/*
  	 * Writes to SControl sometimes get ignored under certain
  	 * controllers (ata_piix SIDPR).  Make sure DET actually is
  	 * cleared.
  	 */
  	do {
  		scontrol = (scontrol & 0x0f0) | 0x300;
  		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
  			return rc;
  		/*
  		 * Some PHYs react badly if SStatus is pounded
  		 * immediately after resuming.  Delay 200ms before
  		 * debouncing.
  		 */
  		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;
  }
  
  /**
   *	sata_link_scr_lpm - manipulate SControl IPM and SPM fields
   *	@link: ATA link to manipulate SControl for
   *	@policy: LPM policy to configure
   *	@spm_wakeup: initiate LPM transition to active state
   *
   *	Manipulate the IPM field of the SControl register of @link
   *	according to @policy.  If @policy is ATA_LPM_MAX_POWER and
   *	@spm_wakeup is %true, the SPM field is manipulated to wake up
   *	the link.  This function also clears PHYRDY_CHG before
   *	returning.
   *
   *	LOCKING:
   *	EH context.
   *
   *	RETURNS:
   *	0 on success, -errno otherwise.
   */
  int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
  		      bool spm_wakeup)
  {
  	struct ata_eh_context *ehc = &link->eh_context;
  	bool woken_up = false;
  	u32 scontrol;
  	int rc;
  
  	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
  	if (rc)
  		return rc;
  
  	switch (policy) {
  	case ATA_LPM_MAX_POWER:
  		/* disable all LPM transitions */
  		scontrol |= (0x7 << 8);
  		/* initiate transition to active state */
  		if (spm_wakeup) {
  			scontrol |= (0x4 << 12);
  			woken_up = true;
  		}
  		break;
  	case ATA_LPM_MED_POWER:
  		/* allow LPM to PARTIAL */
  		scontrol &= ~(0x1 << 8);
  		scontrol |= (0x6 << 8);
  		break;
  	case ATA_LPM_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);
  }
  
  /**
   *	ata_std_prereset - prepare for reset
   *	@link: ATA link to be reset
   *	@deadline: deadline jiffies for the operation
   *
   *	@link is about to be reset.  Initialize it.  Failure from
   *	prereset makes libata abort whole reset sequence and give up
   *	that port, so prereset should be best-effort.  It does its
   *	best to prepare for reset sequence but if things go wrong, it
   *	should just whine, not fail.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, -errno otherwise.
   */
  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;
  }
  
  /**
   *	sata_link_hardreset - reset link via SATA phy reset
   *	@link: link to reset
   *	@timing: timing parameters { interval, duratinon, timeout } in msec
   *	@deadline: deadline jiffies for the operation
   *	@online: optional out parameter indicating link onlineness
   *	@check_ready: optional callback to check link readiness
   *
   *	SATA phy-reset @link using DET bits of SControl register.
   *	After hardreset, link readiness is waited upon using
   *	ata_wait_ready() if @check_ready is specified.  LLDs are
   *	allowed to not specify @check_ready and wait itself after this
   *	function returns.  Device classification is LLD's
   *	responsibility.
   *
   *	*@online is set to one iff reset succeeded and @link is online
   *	after reset.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, -errno otherwise.
   */
  int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
  			unsigned long deadline,
  			bool *online, int (*check_ready)(struct ata_link *))
  {
  	u32 scontrol;
  	int rc;
  
  	DPRINTK("ENTER\n");
  
  	if (online)
  		*online = false;
  
  	if (sata_set_spd_needed(link)) {
  		/* SATA spec says nothing about how to reconfigure
  		 * spd.  To be on the safe side, turn off phy during
  		 * reconfiguration.  This works for at least ICH7 AHCI
  		 * and Sil3124.
  		 */
  		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
  			goto out;
  
  		scontrol = (scontrol & 0x0f0) | 0x304;
  
  		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
  			goto out;
  
  		sata_set_spd(link);
  	}
  
  	/* issue phy wake/reset */
  	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
  		goto out;
  
  	scontrol = (scontrol & 0x0f0) | 0x301;
  
  	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
  		goto out;
  
  	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
  	 * 10.4.2 says at least 1 ms.
  	 */
  	ata_msleep(link->ap, 1);
  
  	/* bring link back */
  	rc = sata_link_resume(link, timing, deadline);
  	if (rc)
  		goto out;
  	/* if link is offline nothing more to do */
  	if (ata_phys_link_offline(link))
  		goto out;
  
  	/* Link is online.  From this point, -ENODEV too is an error. */
  	if (online)
  		*online = true;
  
  	if (sata_pmp_supported(link->ap) && ata_is_host_link(link)) {
  		/* If PMP is supported, we have to do follow-up SRST.
  		 * Some PMPs don't send D2H Reg FIS after hardreset if
  		 * the first port is empty.  Wait only for
  		 * ATA_TMOUT_PMP_SRST_WAIT.
  		 */
  		if (check_ready) {
  			unsigned long pmp_deadline;
  
  			pmp_deadline = ata_deadline(jiffies,
  						    ATA_TMOUT_PMP_SRST_WAIT);
  			if (time_after(pmp_deadline, deadline))
  				pmp_deadline = deadline;
  			ata_wait_ready(link, pmp_deadline, check_ready);
  		}
  		rc = -EAGAIN;
  		goto out;
  	}
  
  	rc = 0;
  	if (check_ready)
  		rc = ata_wait_ready(link, deadline, check_ready);
   out:
  	if (rc && rc != -EAGAIN) {
  		/* online is set iff link is online && reset succeeded */
  		if (online)
  			*online = false;
  		ata_link_err(link, "COMRESET failed (errno=%d)\n", rc);
  	}
  	DPRINTK("EXIT, rc=%d\n", rc);
  	return rc;
  }
  
  /**
   *	sata_std_hardreset - COMRESET w/o waiting or classification
   *	@link: link to reset
   *	@class: resulting class of attached device
   *	@deadline: deadline jiffies for the operation
   *
   *	Standard SATA COMRESET w/o waiting or classification.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 if link offline, -EAGAIN if link online, -errno on errors.
   */
  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;
  }
  
  /**
   *	ata_std_postreset - standard postreset callback
   *	@link: the target ata_link
   *	@classes: classes of attached devices
   *
   *	This function is invoked after a successful reset.  Note that
   *	the device might have been reset more than once using
   *	different reset methods before postreset is invoked.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   */
  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");
  }
  
  /**
   *	ata_dev_same_device - Determine whether new ID matches configured device
   *	@dev: device to compare against
   *	@new_class: class of the new device
   *	@new_id: IDENTIFY page of the new device
   *
   *	Compare @new_class and @new_id against @dev and determine
   *	whether @dev is the device indicated by @new_class and
   *	@new_id.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	1 if @dev matches @new_class and @new_id, 0 otherwise.
   */
  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;
  }
  
  /**
   *	ata_dev_reread_id - Re-read IDENTIFY data
   *	@dev: target ATA device
   *	@readid_flags: read ID flags
   *
   *	Re-read IDENTIFY page and make sure @dev is still attached to
   *	the port.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, negative errno otherwise
   */
  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;
  }
  
  /**
   *	ata_dev_revalidate - Revalidate ATA device
   *	@dev: device to revalidate
   *	@new_class: new class code
   *	@readid_flags: read ID flags
   *
   *	Re-read IDENTIFY page, make sure @dev is still attached to the
   *	port and reconfigure it according to the new IDENTIFY page.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, negative errno otherwise
   */
  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_ZAC &&
  	    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 },
  	{ "Slimtype DVD A  DS8A8SH", NULL,	ATA_HORKAGE_MAX_SEC_LBA48 },
  	{ "Slimtype DVD A  DS8A9SH", NULL,	ATA_HORKAGE_MAX_SEC_LBA48 },
  
  	/*
  	 * Causes silent data corruption with higher max sects.
  	 * http://lkml.kernel.org/g/x49wpy40ysk.fsf@segfault.boston.devel.redhat.com
  	 */
  	{ "ST380013AS",		"3.20",		ATA_HORKAGE_MAX_SEC_1024 },
  
  	/* 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 },
  
  	/* drives which fail FPDMA_AA activation (some may freeze afterwards) */
  	{ "ST1000LM024 HN-M101MBB", "2AR10001",	ATA_HORKAGE_BROKEN_FPDMA_AA },
  	{ "ST1000LM024 HN-M101MBB", "2BA30001",	ATA_HORKAGE_BROKEN_FPDMA_AA },
  	{ "VB0250EAVER",	"HPG7",		ATA_HORKAGE_BROKEN_FPDMA_AA },
  
  	/* 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 },
  
  	/* devices that don't properly handle queued TRIM commands */
  	{ "Micron_M500_*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
  						ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "Crucial_CT*M500*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
  						ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "Micron_M5[15]0_*",		"MU01",	ATA_HORKAGE_NO_NCQ_TRIM |
  						ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "Crucial_CT*M550*",		"MU01",	ATA_HORKAGE_NO_NCQ_TRIM |
  						ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "Crucial_CT*MX100*",		"MU01",	ATA_HORKAGE_NO_NCQ_TRIM |
  						ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "Samsung SSD 8*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
  						ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "FCCT*M500*",			NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
  						ATA_HORKAGE_ZERO_AFTER_TRIM, },
  
  	/* devices that don't properly handle TRIM commands */
  	{ "SuperSSpeed S238*",		NULL,	ATA_HORKAGE_NOTRIM, },
  
  	/*
  	 * As defined, the DRAT (Deterministic Read After Trim) and RZAT
  	 * (Return Zero After Trim) flags in the ATA Command Set are
  	 * unreliable in the sense that they only define what happens if
  	 * the device successfully executed the DSM TRIM command. TRIM
  	 * is only advisory, however, and the device is free to silently
  	 * ignore all or parts of the request.
  	 *
  	 * Whitelist drives that are known to reliably return zeroes
  	 * after TRIM.
  	 */
  
  	/*
  	 * The intel 510 drive has buggy DRAT/RZAT. Explicitly exclude
  	 * that model before whitelisting all other intel SSDs.
  	 */
  	{ "INTEL*SSDSC2MH*",		NULL,	0, },
  
  	{ "Micron*",			NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "Crucial*",			NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "INTEL*SSD*", 		NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "SSD*INTEL*",			NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "Samsung*SSD*",		NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "SAMSUNG*SSD*",		NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
  	{ "ST[1248][0248]0[FH]*",	NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
  
  	/*
  	 * Some WD SATA-I drives spin up and down erratically when the link
  	 * is put into the slumber mode.  We don't have full list of the
  	 * affected devices.  Disable LPM if the device matches one of the
  	 * known prefixes and is SATA-1.  As a side effect LPM partial is
  	 * lost too.
  	 *
  	 * https://bugzilla.kernel.org/show_bug.cgi?id=57211
  	 */
  	{ "WDC WD800JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
  	{ "WDC WD1200JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
  	{ "WDC WD1600JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
  	{ "WDC WD2000JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
  	{ "WDC WD2500JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
  	{ "WDC WD3000JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
  	{ "WDC WD3200JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
  
  	/* End Marker */
  	{ }
  };
  
  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(ad->model_num, model_num)) {
  			if (ad->model_rev == NULL)
  				return ad->horkage;
  			if (glob_match(ad->model_rev, 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;
  }
  
  /**
   *	ata_is_40wire		-	check drive side detection
   *	@dev: device
   *
   *	Perform drive side detection decoding, allowing for device vendors
   *	who can't follow the documentation.
   */
  
  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);
  }
  
  /**
   *	cable_is_40wire		-	40/80/SATA decider
   *	@ap: port to consider
   *
   *	This function encapsulates the policy for speed management
   *	in one place. At the moment we don't cache the result but
   *	there is a good case for setting ap->cbl to the result when
   *	we are called with unknown cables (and figuring out if it
   *	impacts hotplug at all).
   *
   *	Return 1 if the cable appears to be 40 wire.
   */
  
  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;
  }
  
  /**
   *	ata_dev_xfermask - Compute supported xfermask of the given device
   *	@dev: Device to compute xfermask for
   *
   *	Compute supported xfermask of @dev and store it in
   *	dev->*_mask.  This function is responsible for applying all
   *	known limits including host controller limits, device
   *	blacklist, etc...
   *
   *	LOCKING:
   *	None.
   */
  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);
  }
  
  /**
   *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
   *	@dev: Device to which command will be sent
   *
   *	Issue SET FEATURES - XFER MODE command to device @dev
   *	on port @ap.
   *
   *	LOCKING:
   *	PCI/etc. bus probe sem.
   *
   *	RETURNS:
   *	0 on success, AC_ERR_* mask otherwise.
   */
  
  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;
  
  	/* On some disks, this command causes spin-up, so we need longer timeout */
  	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 15000);
  
  	DPRINTK("EXIT, err_mask=%x\n", err_mask);
  	return err_mask;
  }
  
  /**
   *	ata_dev_set_feature - Issue SET FEATURES - SATA FEATURES
   *	@dev: Device to which command will be sent
   *	@enable: Whether to enable or disable the feature
   *	@feature: The sector count represents the feature to set
   *
   *	Issue SET FEATURES - SATA FEATURES command to device @dev
   *	on port @ap with sector count
   *
   *	LOCKING:
   *	PCI/etc. bus probe sem.
   *
   *	RETURNS:
   *	0 on success, AC_ERR_* mask otherwise.
   */
  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);
  
  /**
   *	ata_dev_init_params - Issue INIT DEV PARAMS command
   *	@dev: Device to which command will be sent
   *	@heads: Number of heads (taskfile parameter)
   *	@sectors: Number of sectors (taskfile parameter)
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	0 on success, AC_ERR_* mask otherwise.
   */
  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;
  }
  
  /**
   *	ata_sg_clean - Unmap DMA memory associated with command
   *	@qc: Command containing DMA memory to be released
   *
   *	Unmap all mapped DMA memory associated with this command.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  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;
  }
  
  /**
   *	atapi_check_dma - Check whether ATAPI DMA can be supported
   *	@qc: Metadata associated with taskfile to check
   *
   *	Allow low-level driver to filter ATA PACKET commands, returning
   *	a status indicating whether or not it is OK to use DMA for the
   *	supplied PACKET command.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   *
   *	RETURNS: 0 when ATAPI DMA can be used
   *               nonzero otherwise
   */
  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;
  }
  
  /**
   *	ata_std_qc_defer - Check whether a qc needs to be deferred
   *	@qc: ATA command in question
   *
   *	Non-NCQ commands cannot run with any other command, NCQ or
   *	not.  As upper layer only knows the queue depth, we are
   *	responsible for maintaining exclusion.  This function checks
   *	whether a new command @qc can be issued.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   *
   *	RETURNS:
   *	ATA_DEFER_* if deferring is needed, 0 otherwise.
   */
  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) { }
  
  /**
   *	ata_sg_init - Associate command with scatter-gather table.
   *	@qc: Command to be associated
   *	@sg: Scatter-gather table.
   *	@n_elem: Number of elements in s/g table.
   *
   *	Initialize the data-related elements of queued_cmd @qc
   *	to point to a scatter-gather table @sg, containing @n_elem
   *	elements.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  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;
  }
  
  /**
   *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
   *	@qc: Command with scatter-gather table to be mapped.
   *
   *	DMA-map the scatter-gather table associated with queued_cmd @qc.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   *
   *	RETURNS:
   *	Zero on success, negative on error.
   *
   */
  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;
  }
  
  /**
   *	swap_buf_le16 - swap halves of 16-bit words in place
   *	@buf:  Buffer to swap
   *	@buf_words:  Number of 16-bit words in buffer.
   *
   *	Swap halves of 16-bit words if needed to convert from
   *	little-endian byte order to native cpu byte order, or
   *	vice-versa.
   *
   *	LOCKING:
   *	Inherited from caller.
   */
  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 */
  }
  
  /**
   *	ata_qc_new_init - Request an available ATA command, and initialize it
   *	@dev: Device from whom we request an available command structure
   *	@tag: tag
   *
   *	LOCKING:
   *	None.
   */
  
  struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
  {
  	struct ata_port *ap = dev->link->ap;
  	struct ata_queued_cmd *qc;
  
  	/* no command while frozen */
  	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
  		return NULL;
  
  	/* libsas case */
  	if (ap->flags & ATA_FLAG_SAS_HOST) {
  		tag = ata_sas_allocate_tag(ap);
  		if (tag < 0)
  			return NULL;
  	}
  
  	qc = __ata_qc_from_tag(ap, tag);
  	qc->tag = tag;
  	qc->scsicmd = NULL;
  	qc->ap = ap;
  	qc->dev = dev;
  
  	ata_qc_reinit(qc);
  
  	return qc;
  }
  
  /**
   *	ata_qc_free - free unused ata_queued_cmd
   *	@qc: Command to complete
   *
   *	Designed to free unused ata_queued_cmd object
   *	in case something prevents using it.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  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;
  		if (ap->flags & ATA_FLAG_SAS_HOST)
  			ata_sas_free_tag(tag, ap);
  	}
  }
  
  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;
  }
  
  /**
   *	ata_qc_complete - Complete an active ATA command
   *	@qc: Command to complete
   *
   *	Indicate to the mid and upper layers that an ATA command has
   *	completed, with either an ok or not-ok status.
   *
   *	Refrain from calling this function multiple times when
   *	successfully completing multiple NCQ commands.
   *	ata_qc_complete_multiple() should be used instead, which will
   *	properly update IRQ expect state.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  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);
  			trace_ata_qc_complete_internal(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);
  			trace_ata_qc_complete_failed(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);
  
  		trace_ata_qc_complete_done(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);
  	}
  }
  
  /**
   *	ata_qc_complete_multiple - Complete multiple qcs successfully
   *	@ap: port in question
   *	@qc_active: new qc_active mask
   *
   *	Complete in-flight commands.  This functions is meant to be
   *	called from low-level driver's interrupt routine to complete
   *	requests normally.  ap->qc_active and @qc_active is compared
   *	and commands are completed accordingly.
   *
   *	Always use this function when completing multiple NCQ commands
   *	from IRQ handlers instead of calling ata_qc_complete()
   *	multiple times to keep IRQ expect status properly in sync.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   *
   *	RETURNS:
   *	Number of completed commands on success, -errno otherwise.
   */
  int ata_qc_complete_multiple(struct ata_port *ap, 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;
  }
  
  /**
   *	ata_qc_issue - issue taskfile to device
   *	@qc: command to issue to device
   *
   *	Prepare an ATA command to submission to device.
   *	This includes mapping the data into a DMA-able
   *	area, filling in the S/G table, and finally
   *	writing the taskfile to hardware, starting the command.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  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);
  	trace_ata_qc_issue(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);
  }
  
  /**
   *	sata_scr_valid - test whether SCRs are accessible
   *	@link: ATA link to test SCR accessibility for
   *
   *	Test whether SCRs are accessible for @link.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	1 if SCRs are accessible, 0 otherwise.
   */
  int sata_scr_valid(struct ata_link *link)
  {
  	struct ata_port *ap = link->ap;
  
  	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
  }
  
  /**
   *	sata_scr_read - read SCR register of the specified port
   *	@link: ATA link to read SCR for
   *	@reg: SCR to read
   *	@val: Place to store read value
   *
   *	Read SCR register @reg of @link into *@val.  This function is
   *	guaranteed to succeed if @link is ap->link, the cable type of
   *	the port is SATA and the port implements ->scr_read.
   *
   *	LOCKING:
   *	None if @link is ap->link.  Kernel thread context otherwise.
   *
   *	RETURNS:
   *	0 on success, negative errno on failure.
   */
  int sata_scr_read(struct ata_link *link, int reg, u32 *val)
  {
  	if (ata_is_host_link(link)) {
  		if (sata_scr_valid(link))
  			return link->ap->ops->scr_read(link, reg, val);
  		return -EOPNOTSUPP;
  	}
  
  	return sata_pmp_scr_read(link, reg, val);
  }
  
  /**
   *	sata_scr_write - write SCR register of the specified port
   *	@link: ATA link to write SCR for
   *	@reg: SCR to write
   *	@val: value to write
   *
   *	Write @val to SCR register @reg of @link.  This function is
   *	guaranteed to succeed if @link is ap->link, the cable type of
   *	the port is SATA and the port implements ->scr_read.
   *
   *	LOCKING:
   *	None if @link is ap->link.  Kernel thread context otherwise.
   *
   *	RETURNS:
   *	0 on success, negative errno on failure.
   */
  int sata_scr_write(struct ata_link *link, int reg, u32 val)
  {
  	if (ata_is_host_link(link)) {
  		if (sata_scr_valid(link))
  			return link->ap->ops->scr_write(link, reg, val);
  		return -EOPNOTSUPP;
  	}
  
  	return sata_pmp_scr_write(link, reg, val);
  }
  
  /**
   *	sata_scr_write_flush - write SCR register of the specified port and flush
   *	@link: ATA link to write SCR for
   *	@reg: SCR to write
   *	@val: value to write
   *
   *	This function is identical to sata_scr_write() except that this
   *	function performs flush after writing to the register.
   *
   *	LOCKING:
   *	None if @link is ap->link.  Kernel thread context otherwise.
   *
   *	RETURNS:
   *	0 on success, negative errno on failure.
   */
  int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
  {
  	if (ata_is_host_link(link)) {
  		int rc;
  
  		if (sata_scr_valid(link)) {
  			rc = link->ap->ops->scr_write(link, reg, val);
  			if (rc == 0)
  				rc = link->ap->ops->scr_read(link, reg, &val);
  			return rc;
  		}
  		return -EOPNOTSUPP;
  	}
  
  	return sata_pmp_scr_write(link, reg, val);
  }
  
  /**
   *	ata_phys_link_online - test whether the given link is online
   *	@link: ATA link to test
   *
   *	Test whether @link is online.  Note that this function returns
   *	0 if online status of @link cannot be obtained, so
   *	ata_link_online(link) != !ata_link_offline(link).
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	True if the port online status is available and online.
   */
  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;
  }
  
  /**
   *	ata_phys_link_offline - test whether the given link is offline
   *	@link: ATA link to test
   *
   *	Test whether @link is offline.  Note that this function
   *	returns 0 if offline status of @link cannot be obtained, so
   *	ata_link_online(link) != !ata_link_offline(link).
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	True if the port offline status is available and offline.
   */
  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;
  }
  
  /**
   *	ata_link_online - test whether the given link is online
   *	@link: ATA link to test
   *
   *	Test whether @link is online.  This is identical to
   *	ata_phys_link_online() when there's no slave link.  When
   *	there's a slave link, this function should only be called on
   *	the master link and will return true if any of M/S links is
   *	online.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	True if the port online status is available and online.
   */
  bool ata_link_online(struct ata_link *link)
  {
  	struct ata_link *slave = link->ap->slave_link;
  
  	WARN_ON(link == slave);	/* shouldn't be called on slave link */
  
  	return ata_phys_link_online(link) ||
  		(slave && ata_phys_link_online(slave));
  }
  
  /**
   *	ata_link_offline - test whether the given link is offline
   *	@link: ATA link to test
   *
   *	Test whether @link is offline.  This is identical to
   *	ata_phys_link_offline() when there's no slave link.  When
   *	there's a slave link, this function should only be called on
   *	the master link and will return true if both M/S links are
   *	offline.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	True if the port offline status is available and offline.
   */
  bool ata_link_offline(struct ata_link *link)
  {
  	struct ata_link *slave = link->ap->slave_link;
  
  	WARN_ON(link == slave);	/* shouldn't be called on slave link */
  
  	return ata_phys_link_offline(link) &&
  		(!slave || ata_phys_link_offline(slave));
  }
  
  #ifdef CONFIG_PM
  static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg,
  				unsigned int action, unsigned int ehi_flags,
  				bool async)
  {
  	struct ata_link *link;
  	unsigned long flags;
  
  	/* Previous resume operation might still be in
  	 * progress.  Wait for PM_PENDING to clear.
  	 */
  	if (ap->pflags & ATA_PFLAG_PM_PENDING) {
  		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;
  	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);
  
  	if (!async) {
  		ata_port_wait_eh(ap);
  		WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
  	}
  }
  
  /*
   * 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
   */
  static const unsigned int ata_port_suspend_ehi = ATA_EHI_QUIET
  						 | ATA_EHI_NO_AUTOPSY
  						 | ATA_EHI_NO_RECOVERY;
  
  static void ata_port_suspend(struct ata_port *ap, pm_message_t mesg)
  {
  	ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, false);
  }
  
  static void ata_port_suspend_async(struct ata_port *ap, pm_message_t mesg)
  {
  	ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, true);
  }
  
  static int ata_port_pm_suspend(struct device *dev)
  {
  	struct ata_port *ap = to_ata_port(dev);
  
  	if (pm_runtime_suspended(dev))
  		return 0;
  
  	ata_port_suspend(ap, PMSG_SUSPEND);
  	return 0;
  }
  
  static int ata_port_pm_freeze(struct device *dev)
  {
  	struct ata_port *ap = to_ata_port(dev);
  
  	if (pm_runtime_suspended(dev))
  		return 0;
  
  	ata_port_suspend(ap, PMSG_FREEZE);
  	return 0;
  }
  
  static int ata_port_pm_poweroff(struct device *dev)
  {
  	ata_port_suspend(to_ata_port(dev), PMSG_HIBERNATE);
  	return 0;
  }
  
  static const unsigned int ata_port_resume_ehi = ATA_EHI_NO_AUTOPSY
  						| ATA_EHI_QUIET;
  
  static void ata_port_resume(struct ata_port *ap, pm_message_t mesg)
  {
  	ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, false);
  }
  
  static void ata_port_resume_async(struct ata_port *ap, pm_message_t mesg)
  {
  	ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, true);
  }
  
  static int ata_port_pm_resume(struct device *dev)
  {
  	ata_port_resume_async(to_ata_port(dev), PMSG_RESUME);
  	pm_runtime_disable(dev);
  	pm_runtime_set_active(dev);
  	pm_runtime_enable(dev);
  	return 0;
  }
  
  /*
   * For ODDs, the upper layer will poll for media change every few seconds,
   * which will make it enter and leave suspend state every few seconds. And
   * as each suspend will cause a hard/soft reset, the gain of runtime suspend
   * is very little and the ODD may malfunction after constantly being reset.
   * So the idle callback here will not proceed to suspend if a non-ZPODD capable
   * ODD is attached to the port.
   */
  static int ata_port_runtime_idle(struct device *dev)
  {
  	struct ata_port *ap = to_ata_port(dev);
  	struct ata_link *link;
  	struct ata_device *adev;
  
  	ata_for_each_link(link, ap, HOST_FIRST) {
  		ata_for_each_dev(adev, link, ENABLED)
  			if (adev->class == ATA_DEV_ATAPI &&
  			    !zpodd_dev_enabled(adev))
  				return -EBUSY;
  	}
  
  	return 0;
  }
  
  static int ata_port_runtime_suspend(struct device *dev)
  {
  	ata_port_suspend(to_ata_port(dev), PMSG_AUTO_SUSPEND);
  	return 0;
  }
  
  static int ata_port_runtime_resume(struct device *dev)
  {
  	ata_port_resume(to_ata_port(dev), PMSG_AUTO_RESUME);
  	return 0;
  }
  
  static const struct dev_pm_ops ata_port_pm_ops = {
  	.suspend = ata_port_pm_suspend,
  	.resume = ata_port_pm_resume,
  	.freeze = ata_port_pm_freeze,
  	.thaw = ata_port_pm_resume,
  	.poweroff = ata_port_pm_poweroff,
  	.restore = ata_port_pm_resume,
  
  	.runtime_suspend = ata_port_runtime_suspend,
  	.runtime_resume = ata_port_runtime_resume,
  	.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.
   */
  void ata_sas_port_suspend(struct ata_port *ap)
  {
  	ata_port_suspend_async(ap, PMSG_SUSPEND);
  }
  EXPORT_SYMBOL_GPL(ata_sas_port_suspend);
  
  void ata_sas_port_resume(struct ata_port *ap)
  {
  	ata_port_resume_async(ap, PMSG_RESUME);
  }
  EXPORT_SYMBOL_GPL(ata_sas_port_resume);
  
  /**
   *	ata_host_suspend - suspend host
   *	@host: host to suspend
   *	@mesg: PM message
   *
   *	Suspend @host.  Actual operation is performed by port suspend.
   */
  int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
  {
  	host->dev->power.power_state = mesg;
  	return 0;
  }
  
  /**
   *	ata_host_resume - resume host
   *	@host: host to resume
   *
   *	Resume @host.  Actual operation is performed by port resume.
   */
  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
  };
  
  /**
   *	ata_dev_init - Initialize an ata_device structure
   *	@dev: Device structure to initialize
   *
   *	Initialize @dev in preparation for probing.
   *
   *	LOCKING:
   *	Inherited from caller.
   */
  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;
  }
  
  /**
   *	ata_link_init - Initialize an ata_link structure
   *	@ap: ATA port link is attached to
   *	@link: Link structure to initialize
   *	@pmp: Port multiplier port number
   *
   *	Initialize @link.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   */
  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);
  	}
  }
  
  /**
   *	sata_link_init_spd - Initialize link->sata_spd_limit
   *	@link: Link to configure sata_spd_limit for
   *
   *	Initialize @link->[hw_]sata_spd_limit to the currently
   *	configured value.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep).
   *
   *	RETURNS:
   *	0 on success, -errno on failure.
   */
  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;
  }
  
  /**
   *	ata_port_alloc - allocate and initialize basic ATA port resources
   *	@host: ATA host this allocated port belongs to
   *
   *	Allocate and initialize basic ATA port resources.
   *
   *	RETURNS:
   *	Allocate ATA port on success, NULL on failure.
   *
   *	LOCKING:
   *	Inherited from calling layer (may sleep).
   */
  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->local_port_no = -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);
  }
  
  /**
   *	ata_host_alloc - allocate and init basic ATA host resources
   *	@dev: generic device this host is associated with
   *	@max_ports: maximum number of ATA ports associated with this host
   *
   *	Allocate and initialize basic ATA host resources.  LLD calls
   *	this function to allocate a host, initializes it fully and
   *	attaches it using ata_host_register().
   *
   *	@max_ports ports are allocated and host->n_ports is
   *	initialized to @max_ports.  The caller is allowed to decrease
   *	host->n_ports before calling ata_host_register().  The unused
   *	ports will be automatically freed on registration.
   *
   *	RETURNS:
   *	Allocate ATA host on success, NULL on failure.
   *
   *	LOCKING:
   *	Inherited from calling layer (may sleep).
   */
  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;
  }
  
  /**
   *	ata_host_alloc_pinfo - alloc host and init with port_info array
   *	@dev: generic device this host is associated with
   *	@ppi: array of ATA port_info to initialize host with
   *	@n_ports: number of ATA ports attached to this host
   *
   *	Allocate ATA host and initialize with info from @ppi.  If NULL
   *	terminated, @ppi may contain fewer entries than @n_ports.  The
   *	last entry will be used for the remaining ports.
   *
   *	RETURNS:
   *	Allocate ATA host on success, NULL on failure.
   *
   *	LOCKING:
   *	Inherited from calling layer (may sleep).
   */
  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;
  }
  
  /**
   *	ata_slave_link_init - initialize slave link
   *	@ap: port to initialize slave link for
   *
   *	Create and initialize slave link for @ap.  This enables slave
   *	link handling on the port.
   *
   *	In libata, a port contains links and a link contains devices.
   *	There is single host link but if a PMP is attached to it,
   *	there can be multiple fan-out links.  On SATA, there's usually
   *	a single device connected to a link but PATA and SATA
   *	controllers emulating TF based interface can have two - master
   *	and slave.
   *
   *	However, there are a few controllers which don't fit into this
   *	abstraction too well - SATA controllers which emulate TF
   *	interface with both master and slave devices but also have
   *	separate SCR register sets for each device.  These controllers
   *	need separate links for physical link handling
   *	(e.g. onlineness, link speed) but should be treated like a
   *	traditional M/S controller for everything else (e.g. command
   *	issue, softreset).
   *
   *	slave_link is libata's way of handling this class of
   *	controllers without impacting core layer too much.  For
   *	anything other than physical link handling, the default host
   *	link is used for both master and slave.  For physical link
   *	handling, separate @ap->slave_link is used.  All dirty details
   *	are implemented inside libata core layer.  From LLD's POV, the
   *	only difference is that prereset, hardreset and postreset are
   *	called once more for the slave link, so the reset sequence
   *	looks like the following.
   *
   *	prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
   *	softreset(M) -> postreset(M) -> postreset(S)
   *
   *	Note that softreset is called only for the master.  Softreset
   *	resets both M/S by definition, so SRST on master should handle
   *	both (the standard method will work just fine).
   *
   *	LOCKING:
   *	Should be called before host is registered.
   *
   *	RETURNS:
   *	0 on success, -errno on failure.
   */
  int ata_slave_link_init(struct ata_port *ap)
  {
  	struct ata_link *link;
  
  	WARN_ON(ap->slave_link);
  	WARN_ON(ap->flags & ATA_FLAG_PMP);
  
  	link = kzalloc(sizeof(*link), GFP_KERNEL);
  	if (!link)
  		return -ENOMEM;
  
  	ata_link_init(ap, link, 1);
  	ap->slave_link = link;
  	return 0;
  }
  
  static void ata_host_stop(struct device *gendev, void *res)
  {
  	struct ata_host *host = dev_get_drvdata(gendev);
  	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);
  }
  
  /**
   *	ata_finalize_port_ops - finalize ata_port_operations
   *	@ops: ata_port_operations to finalize
   *
   *	An ata_port_operations can inherit from another ops and that
   *	ops can again inherit from another.  This can go on as many
   *	times as necessary as long as there is no loop in the
   *	inheritance chain.
   *
   *	Ops tables are finalized when the host is started.  NULL or
   *	unspecified entries are inherited from the closet ancestor
   *	which has the method and the entry is populated with it.
   *	After finalization, the ops table directly points to all the
   *	methods and ->inherits is no longer necessary and cleared.
   *
   *	Using ATA_OP_NULL, inheriting ops can force a method to NULL.
   *
   *	LOCKING:
   *	None.
   */
  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);
  }
  
  /**
   *	ata_host_start - start and freeze ports of an ATA host
   *	@host: ATA host to start ports for
   *
   *	Start and then freeze ports of @host.  Started status is
   *	recorded in host->flags, so this function can be called
   *	multiple times.  Ports are guaranteed to get started only
   *	once.  If host->ops isn't initialized yet, its set to the
   *	first non-dummy port ops.
   *
   *	LOCKING:
   *	Inherited from calling layer (may sleep).
   *
   *	RETURNS:
   *	0 if all ports are started successfully, -errno otherwise.
   */
  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;
  }
  
  /**
   *	ata_sas_host_init - Initialize a host struct for sas (ipr, libsas)
   *	@host:	host to initialize
   *	@dev:	device host is attached to
   *	@ops:	port_ops
   *
   */
  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->n_tags = ATA_MAX_QUEUE - 1;
  	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);
  }
  
  /**
   *	ata_host_register - register initialized ATA host
   *	@host: ATA host to register
   *	@sht: template for SCSI host
   *
   *	Register initialized ATA host.  @host is allocated using
   *	ata_host_alloc() and fully initialized by LLD.  This function
   *	starts ports, registers @host with ATA and SCSI layers and
   *	probe registered devices.
   *
   *	LOCKING:
   *	Inherited from calling layer (may sleep).
   *
   *	RETURNS:
   *	0 on success, -errno otherwise.
   */
  int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
  {
  	int i, rc;
  
  	host->n_tags = clamp(sht->can_queue, 1, ATA_MAX_QUEUE - 1);
  
  	/* 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);
  		host->ports[i]->local_port_no = i + 1;
  	}
  
  	/* 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;
  
  }
  
  /**
   *	ata_host_activate - start host, request IRQ and register it
   *	@host: target ATA host
   *	@irq: IRQ to request
   *	@irq_handler: irq_handler used when requesting IRQ
   *	@irq_flags: irq_flags used when requesting IRQ
   *	@sht: scsi_host_template to use when registering the host
   *
   *	After allocating an ATA host and initializing it, most libata
   *	LLDs perform three steps to activate the host - start host,
   *	request IRQ and register it.  This helper takes necessasry
   *	arguments and performs the three steps in one go.
   *
   *	An invalid IRQ skips the IRQ registration and expects the host to
   *	have set polling mode on the port. In this case, @irq_handler
   *	should be NULL.
   *
   *	LOCKING:
   *	Inherited from calling layer (may sleep).
   *
   *	RETURNS:
   *	0 on success, -errno otherwise.
   */
  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_name(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;
  }
  
  /**
   *	ata_port_detach - Detach ATA port in prepration of device removal
   *	@ap: ATA port to be detached
   *
   *	Detach all ATA devices and the associated SCSI devices of @ap;
   *	then, remove the associated SCSI host.  @ap is guaranteed to
   *	be quiescent on return from this function.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep).
   */
  static void ata_port_detach(struct ata_port *ap)
  {
  	unsigned long flags;
  	struct ata_link *link;
  	struct ata_device *dev;
  
  	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:
  	/* clean up zpodd on port removal */
  	ata_for_each_link(link, ap, HOST_FIRST) {
  		ata_for_each_dev(dev, link, ALL) {
  			if (zpodd_dev_enabled(dev))
  				zpodd_exit(dev);
  		}
  	}
  	if (ap->pmp_link) {
  		int i;
  		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
  			ata_tlink_delete(&ap->pmp_link[i]);
  	}
  	/* remove the associated SCSI host */
  	scsi_remove_host(ap->scsi_host);
  	ata_tport_delete(ap);
  }
  
  /**
   *	ata_host_detach - Detach all ports of an ATA host
   *	@host: Host to detach
   *
   *	Detach all ports of @host.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep).
   */
  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
  
  /**
   *	ata_pci_remove_one - PCI layer callback for device removal
   *	@pdev: PCI device that was removed
   *
   *	PCI layer indicates to libata via this hook that hot-unplug or
   *	module unload event has occurred.  Detach all ports.  Resource
   *	release is handled via devres.
   *
   *	LOCKING:
   *	Inherited from PCI layer (may sleep).
   */
  void ata_pci_remove_one(struct pci_dev *pdev)
  {
  	struct ata_host *host = pci_get_drvdata(pdev);
  
  	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 = pci_get_drvdata(pdev);
  	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 = pci_get_drvdata(pdev);
  	int rc;
  
  	rc = ata_pci_device_do_resume(pdev);
  	if (rc == 0)
  		ata_host_resume(host);
  	return rc;
  }
  #endif /* CONFIG_PM */
  
  #endif /* CONFIG_PCI */
  
  /**
   *	ata_platform_remove_one - Platform layer callback for device removal
   *	@pdev: Platform device that was removed
   *
   *	Platform layer indicates to libata via this hook that hot-unplug or
   *	module unload event has occurred.  Detach all ports.  Resource
   *	release is handled via devres.
   *
   *	LOCKING:
   *	Inherited from platform layer (may sleep).
   */
  int ata_platform_remove_one(struct platform_device *pdev)
  {
  	struct ata_host *host = platform_get_drvdata(pdev);
  
  	ata_host_detach(host);
  
  	return 0;
  }
  
  static int __init ata_parse_force_one(char **cur,
  				      struct ata_force_ent *force_ent,
  				      const char **reason)
  {
  	static const struct ata_force_param force_tbl[] __initconst = {
  		{ "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 },
  		{ "noncqtrim",	.horkage_on	= ATA_HORKAGE_NO_NCQ_TRIM },
  		{ "ncqtrim",	.horkage_off	= ATA_HORKAGE_NO_NCQ_TRIM },
  		{ "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 },
  		{ "atapi_dmadir", .horkage_on	= ATA_HORKAGE_ATAPI_DMADIR },
  		{ "disable",	.horkage_on	= ATA_HORKAGE_DISABLE },
  	};
  	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();
  
  	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();
  	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);
  }
  
  /**
   *	ata_msleep - ATA EH owner aware msleep
   *	@ap: ATA port to attribute the sleep to
   *	@msecs: duration to sleep in milliseconds
   *
   *	Sleeps @msecs.  If the current task is owner of @ap's EH, the
   *	ownership is released before going to sleep and reacquired
   *	after the sleep is complete.  IOW, other ports sharing the
   *	@ap->host will be allowed to own the EH while this task is
   *	sleeping.
   *
   *	LOCKING:
   *	Might sleep.
   */
  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);
  }
  
  /**
   *	ata_wait_register - wait until register value changes
   *	@ap: ATA port to wait register for, can be NULL
   *	@reg: IO-mapped register
   *	@mask: Mask to apply to read register value
   *	@val: Wait condition
   *	@interval: polling interval in milliseconds
   *	@timeout: timeout in milliseconds
   *
   *	Waiting for some bits of register to change is a common
   *	operation for ATA controllers.  This function reads 32bit LE
   *	IO-mapped register @reg and tests for the following condition.
   *
   *	(*@reg & mask) != val
   *
   *	If the condition is met, it returns; otherwise, the process is
   *	repeated after @interval_msec until timeout.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep)
   *
   *	RETURNS:
   *	The final register value.
   */
  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;
  }
  
  /**
   *	sata_lpm_ignore_phy_events - test if PHY event should be ignored
   *	@link: Link receiving the event
   *
   *	Test whether the received PHY event has to be ignored or not.
   *
   *	LOCKING:
   *	None:
   *
   *	RETURNS:
   *	True if the event has to be ignored.
   */
  bool sata_lpm_ignore_phy_events(struct ata_link *link)
  {
  	unsigned long lpm_timeout = link->last_lpm_change +
  				    msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY);
  
  	/* if LPM is enabled, PHYRDY doesn't mean anything */
  	if (link->lpm_policy > ATA_LPM_MAX_POWER)
  		return true;
  
  	/* ignore the first PHY event after the LPM policy changed
  	 * as it is might be spurious
  	 */
  	if ((link->flags & ATA_LFLAG_CHANGED) &&
  	    time_before(jiffies, lpm_timeout))
  		return true;
  
  	return false;
  }
  EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);
  
  /*
   * 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
   */
  void ata_port_printk(const struct ata_port *ap, const char *level,
  		     const char *fmt, ...)
  {
  	struct va_format vaf;
  	va_list args;
  
  	va_start(args, fmt);
  
  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	printk("%sata%u: %pV", level, ap->print_id, &vaf);
  
  	va_end(args);
  }
  EXPORT_SYMBOL(ata_port_printk);
  
  void ata_link_printk(const struct ata_link *link, const char *level,
  		     const char *fmt, ...)
  {
  	struct va_format vaf;
  	va_list args;
  
  	va_start(args, fmt);
  
  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	if (sata_pmp_attached(link->ap) || link->ap->slave_link)
  		printk("%sata%u.%02u: %pV",
  		       level, link->ap->print_id, link->pmp, &vaf);
  	else
  		printk("%sata%u: %pV",
  		       level, link->ap->print_id, &vaf);
  
  	va_end(args);
  }
  EXPORT_SYMBOL(ata_link_printk);
  
  void ata_dev_printk(const struct ata_device *dev, const char *level,
  		    const char *fmt, ...)
  {
  	struct va_format vaf;
  	va_list args;
  
  	va_start(args, fmt);
  
  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	printk("%sata%u.%02u: %pV",
  	       level, dev->link->ap->print_id, dev->link->pmp + dev->devno,
  	       &vaf);
  
  	va_end(args);
  }
  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_platform_remove_one);
  
  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);
  