path: root/drivers/ata/libata-core.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  libata-core.c - helper library for ATA
 *
 *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
 *  Copyright 2003-2004 Jeff Garzik
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/driver-api/libata.rst
 *
 *  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)
 *
 * 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.
 */

#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/time.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/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 <asm/unaligned.h>
#include <linux/cdrom.h>
#include <linux/ratelimit.h>
#include <linux/leds.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include <asm/setup.h>

#define CREATE_TRACE_POINTS
#include <trace/events/libata.h>

#include "libata.h"
#include "libata-transport.h"

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,
};
EXPORT_SYMBOL_GPL(sata_port_ops);

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);

#ifdef CONFIG_ATA_FORCE
struct ata_force_param {
	const char	*name;
	u8		cbl;
	u8		spd_limit;
	unsigned long	xfer_mask;
	unsigned int	horkage_on;
	unsigned int	horkage_off;
	u16		lflags_on;
	u16		lflags_off;
};

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[COMMAND_LINE_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/admin-guide/kernel-parameters.rst for details)");
#endif

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 inline bool ata_dev_print_info(struct ata_device *dev)
{
	struct ata_eh_context *ehc = &dev->link->eh_context;

	return ehc->i.flags & ATA_EHI_PRINTINFO;
}

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;
			fallthrough;
		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;
			fallthrough;
		case ATA_LITER_PMP_FIRST:
			if (unlikely(ap->slave_link))
				return ap->slave_link;
			fallthrough;
		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;
}
EXPORT_SYMBOL_GPL(ata_link_next);

/**
 *	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;
}
EXPORT_SYMBOL_GPL(ata_dev_next);

/**
 *	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;
}

#ifdef CONFIG_ATA_FORCE
/**
 *	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_on) {
			link->flags |= fe->param.lflags_on;
			ata_link_notice(link,
					"FORCE: link flag 0x%x forced -> 0x%x\n",
					fe->param.lflags_on, link->flags);
		}
		if (fe->param.lflags_off) {
			link->flags &= ~fe->param.lflags_off;
			ata_link_notice(link,
				"FORCE: link flag 0x%x cleared -> 0x%x\n",
				fe->param.lflags_off, 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);
	}
}
#else
static inline void ata_force_link_limits(struct ata_link *link) { }
static inline void ata_force_xfermask(struct ata_device *dev) { }
static inline void ata_force_horkage(struct ata_device *dev) { }
#endif

/**
 *	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;
		fallthrough;
	default:
		return ATAPI_MISC;
	}
}
EXPORT_SYMBOL_GPL(atapi_cmd_type);

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(const 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");
			return U64_MAX;
		}

		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
 *	@class: IO priority class
 *
 *	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, int class)
{
	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	tf->flags |= tf_flags;

	if (ata_ncq_enabled(dev) && !ata_tag_internal(tag)) {
		/* 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;

		if (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE &&
		    class == IOPRIO_CLASS_RT)
			tf->hob_nsect |= ATA_PRIO_HIGH << ATA_SHIFT_PRIO;
	} 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;

		/* 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);
}
EXPORT_SYMBOL_GPL(ata_pack_xfermask);

/**
 *	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 destination 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;
}
EXPORT_SYMBOL_GPL(ata_xfer_mask2mode);

/**
 *	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;
}
EXPORT_SYMBOL_GPL(ata_xfer_mode2mask);

/**
 *	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(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 ent->shift;
	return -1;
}
EXPORT_SYMBOL_GPL(ata_xfer_mode2shift);

/**
 *	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>";
}
EXPORT_SYMBOL_GPL(ata_mode_string);

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)
		return ATA_DEV_ATA;

	if (tf->lbam == 0x14 && tf->lbah == 0xeb)
		return ATA_DEV_ATAPI;

	if (tf->lbam == 0x69 && tf->lbah == 0x96)
		return ATA_DEV_PMP;

	if (tf->lbam == 0x3c && tf->lbah == 0xc3)
		return ATA_DEV_SEMB;

	if (tf->lbam == 0xcd && tf->lbah == 0xab)
		return ATA_DEV_ZAC;

	return ATA_DEV_UNKNOWN;
}
EXPORT_SYMBOL_GPL(ata_dev_classify);

/**
 *	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;
	}
}
EXPORT_SYMBOL_GPL(ata_id_string);

/**
 *	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';
}
EXPORT_SYMBOL_GPL(ata_id_c_string);

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.error & 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.error & (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)
{
	bool print_info = ata_dev_print_info(dev);
	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
 *	@dev: device from which the information is fetched
 *	@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(struct ata_device *dev, const u16 *id)
{
	ata_dev_dbg(dev,
		"49==0x%04x  53==0x%04x  63==0x%04x  64==0x%04x  75==0x%04x\n"
		"80==0x%04x  81==0x%04x  82==0x%04x  83==0x%04x  84==0x%04x\n"
		"88==0x%04x  93==0x%04x\n",
		id[49], id[53], id[63], id[64], id[75], id[80],
		id[81], id[82], id[83], id[84], 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 it is 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);
}
EXPORT_SYMBOL_GPL(ata_id_xfermask);

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 preempted_tag;
	u32 preempted_sactive;
	u64 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 */
	qc = __ata_qc_from_tag(ap, ATA_TAG_INTERNAL);

	qc->tag = ATA_TAG_INTERNAL;
	qc->hw_tag = 0;
	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);

			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.status & (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;
	} else if (qc->tf.command == ATA_CMD_REQ_SENSE_DATA) {
		qc->result_tf.status |= ATA_SENSE;
	}

	/* 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;
}
EXPORT_SYMBOL_GPL(ata_pio_need_iordy);

/**
 *	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, __le16 *id)
{
<