/*

   *  libata-scsi.c - helper library for ATA
   *
   *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
   *    		    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.t10.org/
   *  - http://www.t13.org/
   *

   */

  #include <linux/slab.h>

  #include <linux/kernel.h>
  #include <linux/blkdev.h>
  #include <linux/spinlock.h>

  #include <linux/export.h>

  #include <scsi/scsi.h>

  #include <scsi/scsi_host.h>

  #include <scsi/scsi_cmnd.h>

  #include <scsi/scsi_eh.h>

  #include <scsi/scsi_device.h>

  #include <scsi/scsi_tcq.h>

  #include <scsi/scsi_transport.h>

  #include <linux/libata.h>

  #include <linux/hdreg.h>

  #include <linux/uaccess.h>

  #include <linux/suspend.h>

  #include <asm/unaligned.h>

  
  #include "libata.h"

  #include "libata-transport.h"

  #define ATA_SCSI_RBUF_SIZE	4096
  
  static DEFINE_SPINLOCK(ata_scsi_rbuf_lock);
  static u8 ata_scsi_rbuf[ATA_SCSI_RBUF_SIZE];

  typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc);

  static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,

  					const struct scsi_device *scsidev);

  static struct ata_device *ata_scsi_find_dev(struct ata_port *ap,

  					    const struct scsi_device *scsidev);

  #define RW_RECOVERY_MPAGE 0x1
  #define RW_RECOVERY_MPAGE_LEN 12
  #define CACHE_MPAGE 0x8
  #define CACHE_MPAGE_LEN 20
  #define CONTROL_MPAGE 0xa
  #define CONTROL_MPAGE_LEN 12
  #define ALL_MPAGES 0x3f
  #define ALL_SUB_MPAGES 0xff

  static const u8 def_rw_recovery_mpage[RW_RECOVERY_MPAGE_LEN] = {

  	RW_RECOVERY_MPAGE,
  	RW_RECOVERY_MPAGE_LEN - 2,

  	(1 << 7),	/* AWRE */

  	0,		/* read retry count */
  	0, 0, 0, 0,
  	0,		/* write retry count */
  	0, 0, 0
  };
  
  static const u8 def_cache_mpage[CACHE_MPAGE_LEN] = {
  	CACHE_MPAGE,
  	CACHE_MPAGE_LEN - 2,
  	0,		/* contains WCE, needs to be 0 for logic */
  	0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0,		/* contains DRA, needs to be 0 for logic */
  	0, 0, 0, 0, 0, 0, 0
  };
  
  static const u8 def_control_mpage[CONTROL_MPAGE_LEN] = {
  	CONTROL_MPAGE,
  	CONTROL_MPAGE_LEN - 2,
  	2,	/* DSENSE=0, GLTSD=1 */
  	0,	/* [QAM+QERR may be 1, see 05-359r1] */
  	0, 0, 0, 0, 0xff, 0xff,
  	0, 30	/* extended self test time, see 05-359r1 */
  };

  static const char *ata_lpm_policy_names[] = {
  	[ATA_LPM_UNKNOWN]	= "max_performance",
  	[ATA_LPM_MAX_POWER]	= "max_performance",
  	[ATA_LPM_MED_POWER]	= "medium_power",
  	[ATA_LPM_MIN_POWER]	= "min_power",

  };

  static ssize_t ata_scsi_lpm_store(struct device *dev,
  				  struct device_attribute *attr,
  				  const char *buf, size_t count)

  {

  	struct Scsi_Host *shost = class_to_shost(dev);

  	struct ata_port *ap = ata_shost_to_port(shost);

  	enum ata_lpm_policy policy;

  	unsigned long flags;

  
  	/* UNKNOWN is internal state, iterate from MAX_POWER */
  	for (policy = ATA_LPM_MAX_POWER;
  	     policy < ARRAY_SIZE(ata_lpm_policy_names); policy++) {
  		const char *name = ata_lpm_policy_names[policy];
  
  		if (strncmp(name, buf, strlen(name)) == 0)

  			break;

  	}

  	if (policy == ARRAY_SIZE(ata_lpm_policy_names))

  		return -EINVAL;

  	spin_lock_irqsave(ap->lock, flags);
  	ap->target_lpm_policy = policy;
  	ata_port_schedule_eh(ap);
  	spin_unlock_irqrestore(ap->lock, flags);

  	return count;
  }

  static ssize_t ata_scsi_lpm_show(struct device *dev,
  				 struct device_attribute *attr, char *buf)

  {

  	struct Scsi_Host *shost = class_to_shost(dev);

  	struct ata_port *ap = ata_shost_to_port(shost);

  	if (ap->target_lpm_policy >= ARRAY_SIZE(ata_lpm_policy_names))

  		return -EINVAL;

  	return snprintf(buf, PAGE_SIZE, "%s
  ",

  			ata_lpm_policy_names[ap->target_lpm_policy]);

  }

  DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,

  	    ata_scsi_lpm_show, ata_scsi_lpm_store);

  EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);

  static ssize_t ata_scsi_park_show(struct device *device,
  				  struct device_attribute *attr, char *buf)
  {
  	struct scsi_device *sdev = to_scsi_device(device);
  	struct ata_port *ap;
  	struct ata_link *link;
  	struct ata_device *dev;

  	unsigned long flags, now;

  	unsigned int uninitialized_var(msecs);
  	int rc = 0;
  
  	ap = ata_shost_to_port(sdev->host);
  
  	spin_lock_irqsave(ap->lock, flags);
  	dev = ata_scsi_find_dev(ap, sdev);
  	if (!dev) {
  		rc = -ENODEV;
  		goto unlock;
  	}
  	if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
  		rc = -EOPNOTSUPP;
  		goto unlock;
  	}
  
  	link = dev->link;

  	now = jiffies;

  	if (ap->pflags & ATA_PFLAG_EH_IN_PROGRESS &&
  	    link->eh_context.unloaded_mask & (1 << dev->devno) &&

  	    time_after(dev->unpark_deadline, now))
  		msecs = jiffies_to_msecs(dev->unpark_deadline - now);

  	else
  		msecs = 0;
  
  unlock:
  	spin_unlock_irq(ap->lock);
  
  	return rc ? rc : snprintf(buf, 20, "%u
  ", msecs);
  }
  
  static ssize_t ata_scsi_park_store(struct device *device,
  				   struct device_attribute *attr,
  				   const char *buf, size_t len)
  {
  	struct scsi_device *sdev = to_scsi_device(device);
  	struct ata_port *ap;
  	struct ata_device *dev;
  	long int input;
  	unsigned long flags;
  	int rc;
  
  	rc = strict_strtol(buf, 10, &input);
  	if (rc || input < -2)
  		return -EINVAL;
  	if (input > ATA_TMOUT_MAX_PARK) {
  		rc = -EOVERFLOW;
  		input = ATA_TMOUT_MAX_PARK;
  	}
  
  	ap = ata_shost_to_port(sdev->host);
  
  	spin_lock_irqsave(ap->lock, flags);
  	dev = ata_scsi_find_dev(ap, sdev);
  	if (unlikely(!dev)) {
  		rc = -ENODEV;
  		goto unlock;
  	}
  	if (dev->class != ATA_DEV_ATA) {
  		rc = -EOPNOTSUPP;
  		goto unlock;
  	}
  
  	if (input >= 0) {
  		if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
  			rc = -EOPNOTSUPP;
  			goto unlock;
  		}
  
  		dev->unpark_deadline = ata_deadline(jiffies, input);
  		dev->link->eh_info.dev_action[dev->devno] |= ATA_EH_PARK;
  		ata_port_schedule_eh(ap);
  		complete(&ap->park_req_pending);
  	} else {
  		switch (input) {
  		case -1:
  			dev->flags &= ~ATA_DFLAG_NO_UNLOAD;
  			break;
  		case -2:
  			dev->flags |= ATA_DFLAG_NO_UNLOAD;
  			break;
  		}
  	}
  unlock:
  	spin_unlock_irqrestore(ap->lock, flags);
  
  	return rc ? rc : len;
  }
  DEVICE_ATTR(unload_heads, S_IRUGO | S_IWUSR,
  	    ata_scsi_park_show, ata_scsi_park_store);
  EXPORT_SYMBOL_GPL(dev_attr_unload_heads);

  static void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
  {
  	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
  
  	scsi_build_sense_buffer(0, cmd->sense_buffer, sk, asc, ascq);
  }

  static ssize_t
  ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
  			  const char *buf, size_t count)
  {
  	struct Scsi_Host *shost = class_to_shost(dev);
  	struct ata_port *ap = ata_shost_to_port(shost);
  	if (ap->ops->em_store && (ap->flags & ATA_FLAG_EM))
  		return ap->ops->em_store(ap, buf, count);
  	return -EINVAL;
  }
  
  static ssize_t
  ata_scsi_em_message_show(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct Scsi_Host *shost = class_to_shost(dev);
  	struct ata_port *ap = ata_shost_to_port(shost);
  
  	if (ap->ops->em_show && (ap->flags & ATA_FLAG_EM))
  		return ap->ops->em_show(ap, buf);
  	return -EINVAL;
  }

  DEVICE_ATTR(em_message, S_IRUGO | S_IWUSR,

  		ata_scsi_em_message_show, ata_scsi_em_message_store);
  EXPORT_SYMBOL_GPL(dev_attr_em_message);
  
  static ssize_t
  ata_scsi_em_message_type_show(struct device *dev, struct device_attribute *attr,
  			      char *buf)
  {
  	struct Scsi_Host *shost = class_to_shost(dev);
  	struct ata_port *ap = ata_shost_to_port(shost);
  
  	return snprintf(buf, 23, "%d
  ", ap->em_message_type);
  }
  DEVICE_ATTR(em_message_type, S_IRUGO,
  		  ata_scsi_em_message_type_show, NULL);
  EXPORT_SYMBOL_GPL(dev_attr_em_message_type);
  
  static ssize_t
  ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct scsi_device *sdev = to_scsi_device(dev);
  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
  
  	if (ap->ops->sw_activity_show && (ap->flags & ATA_FLAG_SW_ACTIVITY))
  		return ap->ops->sw_activity_show(atadev, buf);
  	return -EINVAL;
  }
  
  static ssize_t
  ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
  	const char *buf, size_t count)
  {
  	struct scsi_device *sdev = to_scsi_device(dev);
  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
  	enum sw_activity val;
  	int rc;
  
  	if (ap->ops->sw_activity_store && (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
  		val = simple_strtoul(buf, NULL, 0);
  		switch (val) {
  		case OFF: case BLINK_ON: case BLINK_OFF:
  			rc = ap->ops->sw_activity_store(atadev, val);
  			if (!rc)
  				return count;
  			else
  				return rc;
  		}
  	}
  	return -EINVAL;
  }

  DEVICE_ATTR(sw_activity, S_IWUSR | S_IRUGO, ata_scsi_activity_show,

  			ata_scsi_activity_store);
  EXPORT_SYMBOL_GPL(dev_attr_sw_activity);

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

  static void ata_scsi_invalid_field(struct scsi_cmnd *cmd)

  {
  	ata_scsi_set_sense(cmd, ILLEGAL_REQUEST, 0x24, 0x0);
  	/* "Invalid field in cbd" */

  	cmd->scsi_done(cmd);

  }

  /**
   *	ata_std_bios_param - generic bios head/sector/cylinder calculator used by sd.
   *	@sdev: SCSI device for which BIOS geometry is to be determined
   *	@bdev: block device associated with @sdev
   *	@capacity: capacity of SCSI device
   *	@geom: location to which geometry will be output
   *
   *	Generic bios head/sector/cylinder calculator
   *	used by sd. Most BIOSes nowadays expect a XXX/255/16  (CHS)
   *	mapping. Some situations may arise where the disk is not
   *	bootable if this is not used.
   *
   *	LOCKING:
   *	Defined by the SCSI layer.  We don't really care.
   *
   *	RETURNS:
   *	Zero.
   */
  int ata_std_bios_param(struct scsi_device *sdev, struct block_device *bdev,
  		       sector_t capacity, int geom[])
  {
  	geom[0] = 255;
  	geom[1] = 63;
  	sector_div(capacity, 255*63);
  	geom[2] = capacity;
  
  	return 0;
  }

  /**

   *	ata_scsi_unlock_native_capacity - unlock native capacity
   *	@sdev: SCSI device to adjust device capacity for
   *
   *	This function is called if a partition on @sdev extends beyond
   *	the end of the device.  It requests EH to unlock HPA.
   *
   *	LOCKING:
   *	Defined by the SCSI layer.  Might sleep.
   */
  void ata_scsi_unlock_native_capacity(struct scsi_device *sdev)
  {
  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  	struct ata_device *dev;
  	unsigned long flags;
  
  	spin_lock_irqsave(ap->lock, flags);
  
  	dev = ata_scsi_find_dev(ap, sdev);
  	if (dev && dev->n_sectors < dev->n_native_sectors) {
  		dev->flags |= ATA_DFLAG_UNLOCK_HPA;
  		dev->link->eh_info.action |= ATA_EH_RESET;
  		ata_port_schedule_eh(ap);
  	}
  
  	spin_unlock_irqrestore(ap->lock, flags);
  	ata_port_wait_eh(ap);
  }
  
  /**

   *	ata_get_identity - Handler for HDIO_GET_IDENTITY ioctl

   *	@ap: target port

   *	@sdev: SCSI device to get identify data for
   *	@arg: User buffer area for identify data
   *
   *	LOCKING:
   *	Defined by the SCSI layer.  We don't really care.
   *
   *	RETURNS:
   *	Zero on success, negative errno on error.
   */

  static int ata_get_identity(struct ata_port *ap, struct scsi_device *sdev,
  			    void __user *arg)

  {

  	struct ata_device *dev = ata_scsi_find_dev(ap, sdev);
  	u16 __user *dst = arg;
  	char buf[40];
  
  	if (!dev)
  		return -ENOMSG;
  
  	if (copy_to_user(dst, dev->id, ATA_ID_WORDS * sizeof(u16)))
  		return -EFAULT;
  
  	ata_id_string(dev->id, buf, ATA_ID_PROD, ATA_ID_PROD_LEN);
  	if (copy_to_user(dst + ATA_ID_PROD, buf, ATA_ID_PROD_LEN))
  		return -EFAULT;
  
  	ata_id_string(dev->id, buf, ATA_ID_FW_REV, ATA_ID_FW_REV_LEN);
  	if (copy_to_user(dst + ATA_ID_FW_REV, buf, ATA_ID_FW_REV_LEN))
  		return -EFAULT;
  
  	ata_id_string(dev->id, buf, ATA_ID_SERNO, ATA_ID_SERNO_LEN);
  	if (copy_to_user(dst + ATA_ID_SERNO, buf, ATA_ID_SERNO_LEN))
  		return -EFAULT;
  
  	return 0;
  }
  
  /**

   *	ata_cmd_ioctl - Handler for HDIO_DRIVE_CMD ioctl

   *	@scsidev: Device to which we are issuing command

   *	@arg: User provided data for issuing command
   *
   *	LOCKING:
   *	Defined by the SCSI layer.  We don't really care.
   *
   *	RETURNS:
   *	Zero on success, negative errno on error.
   */

  int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
  {
  	int rc = 0;
  	u8 scsi_cmd[MAX_COMMAND_SIZE];

  	u8 args[4], *argbuf = NULL, *sensebuf = NULL;

  	int argsize = 0;

  	enum dma_data_direction data_dir;

  	int cmd_result;

  	if (arg == NULL)

  		return -EINVAL;
  
  	if (copy_from_user(args, arg, sizeof(args)))
  		return -EFAULT;

  	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
  	if (!sensebuf)
  		return -ENOMEM;

  	memset(scsi_cmd, 0, sizeof(scsi_cmd));
  
  	if (args[3]) {

  		argsize = ATA_SECT_SIZE * args[3];

  		argbuf = kmalloc(argsize, GFP_KERNEL);

  		if (argbuf == NULL) {
  			rc = -ENOMEM;
  			goto error;
  		}

  
  		scsi_cmd[1]  = (4 << 1); /* PIO Data-in */
  		scsi_cmd[2]  = 0x0e;     /* no off.line or cc, read from dev,

  					    block count in sector count field */

  		data_dir = DMA_FROM_DEVICE;

  	} else {
  		scsi_cmd[1]  = (3 << 1); /* Non-data */

  		scsi_cmd[2]  = 0x20;     /* cc but no off.line or data xfer */

  		data_dir = DMA_NONE;

  	}
  
  	scsi_cmd[0] = ATA_16;
  
  	scsi_cmd[4] = args[2];

  	if (args[0] == ATA_CMD_SMART) { /* hack -- ide driver does this too */

  		scsi_cmd[6]  = args[3];
  		scsi_cmd[8]  = args[1];
  		scsi_cmd[10] = 0x4f;
  		scsi_cmd[12] = 0xc2;
  	} else {
  		scsi_cmd[6]  = args[1];
  	}
  	scsi_cmd[14] = args[0];
  
  	/* Good values for timeout and retries?  Values below
  	   from scsi_ioctl_send_command() for default case... */

  	cmd_result = scsi_execute(scsidev, scsi_cmd, data_dir, argbuf, argsize,

  				  sensebuf, (10*HZ), 5, 0, NULL);

  
  	if (driver_byte(cmd_result) == DRIVER_SENSE) {/* sense data available */
  		u8 *desc = sensebuf + 8;
  		cmd_result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */
  
  		/* If we set cc then ATA pass-through will cause a
  		 * check condition even if no error. Filter that. */
  		if (cmd_result & SAM_STAT_CHECK_CONDITION) {
  			struct scsi_sense_hdr sshdr;
  			scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE,

  					     &sshdr);
  			if (sshdr.sense_key == 0 &&
  			    sshdr.asc == 0 && sshdr.ascq == 0)

  				cmd_result &= ~SAM_STAT_CHECK_CONDITION;
  		}
  
  		/* Send userspace a few ATA registers (same as drivers/ide) */

  		if (sensebuf[0] == 0x72 &&	/* format is "descriptor" */
  		    desc[0] == 0x09) {		/* code is "ATA Descriptor" */
  			args[0] = desc[13];	/* status */
  			args[1] = desc[3];	/* error */
  			args[2] = desc[5];	/* sector count (0:7) */

  			if (copy_to_user(arg, args, sizeof(args)))
  				rc = -EFAULT;
  		}
  	}
  
  
  	if (cmd_result) {

  		rc = -EIO;
  		goto error;
  	}

  	if ((argbuf)

  	 && copy_to_user(arg + sizeof(args), argbuf, argsize))

  		rc = -EFAULT;
  error:

  	kfree(sensebuf);

  	kfree(argbuf);

  	return rc;
  }
  
  /**
   *	ata_task_ioctl - Handler for HDIO_DRIVE_TASK ioctl

   *	@scsidev: Device to which we are issuing command

   *	@arg: User provided data for issuing command
   *
   *	LOCKING:
   *	Defined by the SCSI layer.  We don't really care.
   *
   *	RETURNS:
   *	Zero on success, negative errno on error.
   */
  int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
  {
  	int rc = 0;
  	u8 scsi_cmd[MAX_COMMAND_SIZE];

  	u8 args[7], *sensebuf = NULL;
  	int cmd_result;

  	if (arg == NULL)

  		return -EINVAL;
  
  	if (copy_from_user(args, arg, sizeof(args)))
  		return -EFAULT;

  	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
  	if (!sensebuf)
  		return -ENOMEM;

  	memset(scsi_cmd, 0, sizeof(scsi_cmd));
  	scsi_cmd[0]  = ATA_16;
  	scsi_cmd[1]  = (3 << 1); /* Non-data */

  	scsi_cmd[2]  = 0x20;     /* cc but no off.line or data xfer */

  	scsi_cmd[4]  = args[1];
  	scsi_cmd[6]  = args[2];
  	scsi_cmd[8]  = args[3];
  	scsi_cmd[10] = args[4];
  	scsi_cmd[12] = args[5];

  	scsi_cmd[13] = args[6] & 0x4f;

  	scsi_cmd[14] = args[0];

  	/* Good values for timeout and retries?  Values below

  	   from scsi_ioctl_send_command() for default case... */

  	cmd_result = scsi_execute(scsidev, scsi_cmd, DMA_NONE, NULL, 0,

  				sensebuf, (10*HZ), 5, 0, NULL);

  
  	if (driver_byte(cmd_result) == DRIVER_SENSE) {/* sense data available */
  		u8 *desc = sensebuf + 8;
  		cmd_result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */
  
  		/* If we set cc then ATA pass-through will cause a
  		 * check condition even if no error. Filter that. */
  		if (cmd_result & SAM_STAT_CHECK_CONDITION) {
  			struct scsi_sense_hdr sshdr;
  			scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE,
  						&sshdr);

  			if (sshdr.sense_key == 0 &&
  				sshdr.asc == 0 && sshdr.ascq == 0)

  				cmd_result &= ~SAM_STAT_CHECK_CONDITION;
  		}
  
  		/* Send userspace ATA registers */
  		if (sensebuf[0] == 0x72 &&	/* format is "descriptor" */
  				desc[0] == 0x09) {/* code is "ATA Descriptor" */
  			args[0] = desc[13];	/* status */
  			args[1] = desc[3];	/* error */
  			args[2] = desc[5];	/* sector count (0:7) */
  			args[3] = desc[7];	/* lbal */
  			args[4] = desc[9];	/* lbam */
  			args[5] = desc[11];	/* lbah */
  			args[6] = desc[12];	/* select */
  			if (copy_to_user(arg, args, sizeof(args)))
  				rc = -EFAULT;
  		}
  	}
  
  	if (cmd_result) {

  		rc = -EIO;

  		goto error;
  	}

   error:
  	kfree(sensebuf);

  	return rc;
  }

  static int ata_ioc32(struct ata_port *ap)
  {
  	if (ap->flags & ATA_FLAG_PIO_DMA)
  		return 1;
  	if (ap->pflags & ATA_PFLAG_PIO32)
  		return 1;
  	return 0;
  }

  int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
  		     int cmd, void __user *arg)

  {

  	int val = -EINVAL, rc = -EINVAL;

  	unsigned long flags;

  	switch (cmd) {
  	case ATA_IOC_GET_IO32:

  		spin_lock_irqsave(ap->lock, flags);
  		val = ata_ioc32(ap);
  		spin_unlock_irqrestore(ap->lock, flags);

  		if (copy_to_user(arg, &val, 1))
  			return -EFAULT;
  		return 0;
  
  	case ATA_IOC_SET_IO32:
  		val = (unsigned long) arg;

  		rc = 0;
  		spin_lock_irqsave(ap->lock, flags);
  		if (ap->pflags & ATA_PFLAG_PIO32CHANGE) {
  			if (val)
  				ap->pflags |= ATA_PFLAG_PIO32;
  			else
  				ap->pflags &= ~ATA_PFLAG_PIO32;
  		} else {
  			if (val != ata_ioc32(ap))
  				rc = -EINVAL;
  		}
  		spin_unlock_irqrestore(ap->lock, flags);
  		return rc;

  	case HDIO_GET_IDENTITY:

  		return ata_get_identity(ap, scsidev, arg);

  	case HDIO_DRIVE_CMD:
  		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
  			return -EACCES;
  		return ata_cmd_ioctl(scsidev, arg);
  
  	case HDIO_DRIVE_TASK:
  		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
  			return -EACCES;
  		return ata_task_ioctl(scsidev, arg);

  	default:
  		rc = -ENOTTY;
  		break;
  	}

  	return rc;
  }

  EXPORT_SYMBOL_GPL(ata_sas_scsi_ioctl);
  
  int ata_scsi_ioctl(struct scsi_device *scsidev, int cmd, void __user *arg)
  {
  	return ata_sas_scsi_ioctl(ata_shost_to_port(scsidev->host),
  				scsidev, cmd, arg);
  }
  EXPORT_SYMBOL_GPL(ata_scsi_ioctl);

  
  /**
   *	ata_scsi_qc_new - acquire new ata_queued_cmd reference

   *	@dev: ATA device to which the new command is attached
   *	@cmd: SCSI command that originated this ATA command

   *
   *	Obtain a reference to an unused ata_queued_cmd structure,
   *	which is the basic libata structure representing a single
   *	ATA command sent to the hardware.
   *
   *	If a command was available, fill in the SCSI-specific
   *	portions of the structure with information on the
   *	current command.
   *
   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   *
   *	RETURNS:
   *	Command allocated, or %NULL if none available.
   */

  static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,

  					      struct scsi_cmnd *cmd)

  {
  	struct ata_queued_cmd *qc;

  	qc = ata_qc_new_init(dev);

  	if (qc) {
  		qc->scsicmd = cmd;

  		qc->scsidone = cmd->scsi_done;

  		qc->sg = scsi_sglist(cmd);

  		qc->n_elem = scsi_sg_count(cmd);

  	} else {
  		cmd->result = (DID_OK << 16) | (QUEUE_FULL << 1);

  		cmd->scsi_done(cmd);

  	}
  
  	return qc;
  }

  static void ata_qc_set_pc_nbytes(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *scmd = qc->scsicmd;
  
  	qc->extrabytes = scmd->request->extra_len;
  	qc->nbytes = scsi_bufflen(scmd) + qc->extrabytes;
  }

  /**

   *	ata_dump_status - user friendly display of error info
   *	@id: id of the port in question
   *	@tf: ptr to filled out taskfile
   *
   *	Decode and dump the ATA error/status registers for the user so
   *	that they have some idea what really happened at the non
   *	make-believe layer.
   *
   *	LOCKING:
   *	inherited from caller
   */

  static void ata_dump_status(unsigned id, struct ata_taskfile *tf)

  {
  	u8 stat = tf->command, err = tf->feature;
  
  	printk(KERN_WARNING "ata%u: status=0x%02x { ", id, stat);
  	if (stat & ATA_BUSY) {
  		printk("Busy }
  ");	/* Data is not valid in this case */
  	} else {
  		if (stat & 0x40)	printk("DriveReady ");
  		if (stat & 0x20)	printk("DeviceFault ");
  		if (stat & 0x10)	printk("SeekComplete ");
  		if (stat & 0x08)	printk("DataRequest ");
  		if (stat & 0x04)	printk("CorrectedError ");
  		if (stat & 0x02)	printk("Index ");
  		if (stat & 0x01)	printk("Error ");
  		printk("}
  ");
  
  		if (err) {
  			printk(KERN_WARNING "ata%u: error=0x%02x { ", id, err);
  			if (err & 0x04)		printk("DriveStatusError ");
  			if (err & 0x80) {
  				if (err & 0x04)	printk("BadCRC ");
  				else		printk("Sector ");
  			}
  			if (err & 0x40)		printk("UncorrectableError ");
  			if (err & 0x10)		printk("SectorIdNotFound ");
  			if (err & 0x02)		printk("TrackZeroNotFound ");
  			if (err & 0x01)		printk("AddrMarkNotFound ");
  			printk("}
  ");
  		}
  	}
  }
  
  /**

   *	ata_to_sense_error - convert ATA error to SCSI error

   *	@id: ATA device number

   *	@drv_stat: value contained in ATA status register

   *	@drv_err: value contained in ATA error register
   *	@sk: the sense key we'll fill out
   *	@asc: the additional sense code we'll fill out
   *	@ascq: the additional sense code qualifier we'll fill out

   *	@verbose: be verbose

   *

   *	Converts an ATA error into a SCSI error.  Fill out pointers to
   *	SK, ASC, and ASCQ bytes for later use in fixed or descriptor
   *	format sense blocks.

   *
   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   */

  static void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk,
  			       u8 *asc, u8 *ascq, int verbose)

  {

  	int i;

  	/* Based on the 3ware driver translation table */

  	static const unsigned char sense_table[][4] = {

  		/* BBD|ECC|ID|MAR */
  		{0xd1, 		ABORTED_COMMAND, 0x00, 0x00}, 	// Device busy                  Aborted command
  		/* BBD|ECC|ID */
  		{0xd0,  	ABORTED_COMMAND, 0x00, 0x00}, 	// Device busy                  Aborted command
  		/* ECC|MC|MARK */
  		{0x61, 		HARDWARE_ERROR, 0x00, 0x00}, 	// Device fault                 Hardware error
  		/* ICRC|ABRT */		/* NB: ICRC & !ABRT is BBD */
  		{0x84, 		ABORTED_COMMAND, 0x47, 0x00}, 	// Data CRC error               SCSI parity error
  		/* MC|ID|ABRT|TRK0|MARK */
  		{0x37, 		NOT_READY, 0x04, 0x00}, 	// Unit offline                 Not ready
  		/* MCR|MARK */
  		{0x09, 		NOT_READY, 0x04, 0x00}, 	// Unrecovered disk error       Not ready
  		/*  Bad address mark */
  		{0x01, 		MEDIUM_ERROR, 0x13, 0x00}, 	// Address mark not found       Address mark not found for data field
  		/* TRK0 */
  		{0x02, 		HARDWARE_ERROR, 0x00, 0x00}, 	// Track 0 not found		  Hardware error
  		/* Abort & !ICRC */
  		{0x04, 		ABORTED_COMMAND, 0x00, 0x00}, 	// Aborted command              Aborted command
  		/* Media change request */
  		{0x08, 		NOT_READY, 0x04, 0x00}, 	// Media change request	  FIXME: faking offline
  		/* SRV */
  		{0x10, 		ABORTED_COMMAND, 0x14, 0x00}, 	// ID not found                 Recorded entity not found
  		/* Media change */
  		{0x08,  	NOT_READY, 0x04, 0x00}, 	// Media change		  FIXME: faking offline
  		/* ECC */
  		{0x40, 		MEDIUM_ERROR, 0x11, 0x04}, 	// Uncorrectable ECC error      Unrecovered read error
  		/* BBD - block marked bad */
  		{0x80, 		MEDIUM_ERROR, 0x11, 0x04}, 	// Block marked bad		  Medium error, unrecovered read error
  		{0xFF, 0xFF, 0xFF, 0xFF}, // END mark
  	};

  	static const unsigned char stat_table[][4] = {

  		/* Must be first because BUSY means no other bits valid */
  		{0x80, 		ABORTED_COMMAND, 0x47, 0x00},	// Busy, fake parity for now
  		{0x20, 		HARDWARE_ERROR,  0x00, 0x00}, 	// Device fault
  		{0x08, 		ABORTED_COMMAND, 0x47, 0x00},	// Timed out in xfer, fake parity for now
  		{0x04, 		RECOVERED_ERROR, 0x11, 0x00},	// Recovered ECC error	  Medium error, recovered
  		{0xFF, 0xFF, 0xFF, 0xFF}, // END mark
  	};

  	/*
  	 *	Is this an error we can process/parse
  	 */

  	if (drv_stat & ATA_BUSY) {
  		drv_err = 0;	/* Ignore the err bits, they're invalid */

  	}

  
  	if (drv_err) {
  		/* Look for drv_err */
  		for (i = 0; sense_table[i][0] != 0xFF; i++) {
  			/* Look for best matches first */

  			if ((sense_table[i][0] & drv_err) ==

  			    sense_table[i][0]) {
  				*sk = sense_table[i][1];
  				*asc = sense_table[i][2];
  				*ascq = sense_table[i][3];
  				goto translate_done;
  			}
  		}
  		/* No immediate match */

  		if (verbose)
  			printk(KERN_WARNING "ata%u: no sense translation for "
  			       "error 0x%02x
  ", id, drv_err);

  	}

  
  	/* Fall back to interpreting status bits */
  	for (i = 0; stat_table[i][0] != 0xFF; i++) {
  		if (stat_table[i][0] & drv_stat) {
  			*sk = stat_table[i][1];
  			*asc = stat_table[i][2];
  			*ascq = stat_table[i][3];
  			goto translate_done;

  		}

  	}
  	/* No error?  Undecoded? */

  	if (verbose)
  		printk(KERN_WARNING "ata%u: no sense translation for "
  		       "status: 0x%02x
  ", id, drv_stat);

  	/* We need a sensible error return here, which is tricky, and one
  	   that won't cause people to do things like return a disk wrongly */
  	*sk = ABORTED_COMMAND;
  	*asc = 0x00;
  	*ascq = 0x00;

  
   translate_done:

  	if (verbose)
  		printk(KERN_ERR "ata%u: translated ATA stat/err 0x%02x/%02x "
  		       "to SCSI SK/ASC/ASCQ 0x%x/%02x/%02x
  ",
  		       id, drv_stat, drv_err, *sk, *asc, *ascq);

  	return;
  }
  
  /*

   *	ata_gen_passthru_sense - Generate check condition sense block.

   *	@qc: Command that completed.
   *
   *	This function is specific to the ATA descriptor format sense
   *	block specified for the ATA pass through commands.  Regardless
   *	of whether the command errored or not, return a sense
   *	block. Copy all controller registers into the sense
   *	block. Clear sense key, ASC & ASCQ if there is no error.
   *
   *	LOCKING:

   *	None.

   */

  static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)

  {
  	struct scsi_cmnd *cmd = qc->scsicmd;

  	struct ata_taskfile *tf = &qc->result_tf;

  	unsigned char *sb = cmd->sense_buffer;
  	unsigned char *desc = sb + 8;

  	int verbose = qc->ap->ops->error_handler == NULL;

  
  	memset(sb, 0, SCSI_SENSE_BUFFERSIZE);

  	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;

  
  	/*

  	 * Use ata_to_sense_error() to map status register bits
  	 * onto sense key, asc & ascq.
  	 */

  	if (qc->err_mask ||
  	    tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {

  		ata_to_sense_error(qc->ap->print_id, tf->command, tf->feature,

  				   &sb[1], &sb[2], &sb[3], verbose);

  		sb[1] &= 0x0f;

  	}

  	/*
  	 * Sense data is current and format is descriptor.
  	 */
  	sb[0] = 0x72;

  	desc[0] = 0x09;

  	/* set length of additional sense data */
  	sb[7] = 14;
  	desc[1] = 12;

  
  	/*
  	 * Copy registers into sense buffer.
  	 */
  	desc[2] = 0x00;
  	desc[3] = tf->feature;	/* == error reg */
  	desc[5] = tf->nsect;
  	desc[7] = tf->lbal;
  	desc[9] = tf->lbam;
  	desc[11] = tf->lbah;
  	desc[12] = tf->device;
  	desc[13] = tf->command; /* == status reg */
  
  	/*
  	 * Fill in Extend bit, and the high order bytes
  	 * if applicable.
  	 */
  	if (tf->flags & ATA_TFLAG_LBA48) {
  		desc[2] |= 0x01;
  		desc[4] = tf->hob_nsect;
  		desc[6] = tf->hob_lbal;
  		desc[8] = tf->hob_lbam;
  		desc[10] = tf->hob_lbah;

  	}

  }

  /**

   *	ata_gen_ata_sense - generate a SCSI fixed sense block

   *	@qc: Command that we are erroring out
   *

   *	Generate sense block for a failed ATA command @qc.  Descriptor

   *	format is used to accommodate LBA48 block address.

   *
   *	LOCKING:

   *	None.

   */

  static void ata_gen_ata_sense(struct ata_queued_cmd *qc)

  {

  	struct ata_device *dev = qc->dev;

  	struct scsi_cmnd *cmd = qc->scsicmd;

  	struct ata_taskfile *tf = &qc->result_tf;

  	unsigned char *sb = cmd->sense_buffer;

  	unsigned char *desc = sb + 8;

  	int verbose = qc->ap->ops->error_handler == NULL;

  	u64 block;

  
  	memset(sb, 0, SCSI_SENSE_BUFFERSIZE);

  	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;

  	/* sense data is current and format is descriptor */
  	sb[0] = 0x72;
  
  	/* Use ata_to_sense_error() to map status register bits

  	 * onto sense key, asc & ascq.
  	 */

  	if (qc->err_mask ||
  	    tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {

  		ata_to_sense_error(qc->ap->print_id, tf->command, tf->feature,

  				   &sb[1], &sb[2], &sb[3], verbose);
  		sb[1] &= 0x0f;

  	}

  	block = ata_tf_read_block(&qc->result_tf, dev);

  	/* information sense data descriptor */
  	sb[7] = 12;
  	desc[0] = 0x00;
  	desc[1] = 10;

  	desc[2] |= 0x80;	/* valid */
  	desc[6] = block >> 40;
  	desc[7] = block >> 32;
  	desc[8] = block >> 24;
  	desc[9] = block >> 16;
  	desc[10] = block >> 8;
  	desc[11] = block;

  }

  static void ata_scsi_sdev_config(struct scsi_device *sdev)
  {
  	sdev->use_10_for_rw = 1;
  	sdev->use_10_for_ms = 1;

  
  	/* Schedule policy is determined by ->qc_defer() callback and
  	 * it needs to see every deferred qc.  Set dev_blocked to 1 to
  	 * prevent SCSI midlayer from automatically deferring
  	 * requests.
  	 */
  	sdev->max_device_blocked = 1;

  }

  /**
   *	atapi_drain_needed - Check whether data transfer may overflow

   *	@rq: request to be checked

   *
   *	ATAPI commands which transfer variable length data to host
   *	might overflow due to application error or hardare bug.  This
   *	function checks whether overflow should be drained and ignored
   *	for @request.
   *
   *	LOCKING:
   *	None.
   *
   *	RETURNS:
   *	1 if ; otherwise, 0.
   */
  static int atapi_drain_needed(struct request *rq)
  {

  	if (likely(rq->cmd_type != REQ_TYPE_BLOCK_PC))

  		return 0;

  	if (!blk_rq_bytes(rq) || (rq->cmd_flags & REQ_WRITE))

  		return 0;
  
  	return atapi_cmd_type(rq->cmd[0]) == ATAPI_MISC;
  }
  
  static int ata_scsi_dev_config(struct scsi_device *sdev,
  			       struct ata_device *dev)

  {

  	struct request_queue *q = sdev->request_queue;

  	if (!ata_id_has_unload(dev->id))
  		dev->flags |= ATA_DFLAG_NO_UNLOAD;

  	/* configure max sectors */

  	blk_queue_max_hw_sectors(q, dev->max_sectors);

  	if (dev->class == ATA_DEV_ATAPI) {

  		void *buf;

  		sdev->sector_size = ATA_SECT_SIZE;
  
  		/* set DMA padding */

  		blk_queue_update_dma_pad(q, ATA_DMA_PAD_SZ - 1);

  
  		/* configure draining */
  		buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);
  		if (!buf) {

  			ata_dev_err(dev, "drain buffer allocation failed
  ");

  			return -ENOMEM;
  		}
  
  		blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
  	} else {

  		sdev->sector_size = ata_id_logical_sector_size(dev->id);

  		sdev->manage_start_stop = 1;

  	}

  	/*
  	 * ata_pio_sectors() expects buffer for each sector to not cross
  	 * page boundary.  Enforce it by requiring buffers to be sector
  	 * aligned, which works iff sector_size is not larger than
  	 * PAGE_SIZE.  ATAPI devices also need the alignment as
  	 * IDENTIFY_PACKET is executed as ATA_PROT_PIO.
  	 */
  	if (sdev->sector_size > PAGE_SIZE)

  		ata_dev_warn(dev,

  			"sector_size=%u > PAGE_SIZE, PIO may malfunction
  ",
  			sdev->sector_size);

  	blk_queue_update_dma_alignment(q, sdev->sector_size - 1);

  	if (dev->flags & ATA_DFLAG_AN)
  		set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);

  	if (dev->flags & ATA_DFLAG_NCQ) {
  		int depth;
  
  		depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
  		depth = min(ATA_MAX_QUEUE - 1, depth);

  		scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);

  	}

  	blk_queue_flush_queueable(q, false);

  	dev->sdev = sdev;

  	return 0;

  }

  /**
   *	ata_scsi_slave_config - Set SCSI device attributes
   *	@sdev: SCSI device to examine
   *
   *	This is called before we actually start reading
   *	and writing to the device, to configure certain
   *	SCSI mid-layer behaviors.
   *
   *	LOCKING:
   *	Defined by SCSI layer.  We don't really care.
   */
  
  int ata_scsi_slave_config(struct scsi_device *sdev)
  {

  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);

  	int rc = 0;

  	ata_scsi_sdev_config(sdev);

  	if (dev)

  		rc = ata_scsi_dev_config(sdev, dev);

  	return rc;

  }
  
  /**

   *	ata_scsi_slave_destroy - SCSI device is about to be destroyed
   *	@sdev: SCSI device to be destroyed
   *
   *	@sdev is about to be destroyed for hot/warm unplugging.  If
   *	this unplugging was initiated by libata as indicated by NULL
   *	dev->sdev, this function doesn't have to do anything.
   *	Otherwise, SCSI layer initiated warm-unplug is in progress.
   *	Clear dev->sdev, schedule the device for ATA detach and invoke
   *	EH.
   *
   *	LOCKING:
   *	Defined by SCSI layer.  We don't really care.
   */
  void ata_scsi_slave_destroy(struct scsi_device *sdev)
  {
  	struct ata_port *ap = ata_shost_to_port(sdev->host);

  	struct request_queue *q = sdev->request_queue;

  	unsigned long flags;
  	struct ata_device *dev;
  
  	if (!ap->ops->error_handler)
  		return;

  	spin_lock_irqsave(ap->lock, flags);

  	dev = __ata_scsi_find_dev(ap, sdev);
  	if (dev && dev->sdev) {
  		/* SCSI device already in CANCEL state, no need to offline it */
  		dev->sdev = NULL;
  		dev->flags |= ATA_DFLAG_DETACH;
  		ata_port_schedule_eh(ap);
  	}

  	spin_unlock_irqrestore(ap->lock, flags);

  
  	kfree(q->dma_drain_buffer);
  	q->dma_drain_buffer = NULL;
  	q->dma_drain_size = 0;

  }
  
  /**

   *	__ata_change_queue_depth - helper for ata_scsi_change_queue_depth

   *	@ap: ATA port to which the device change the queue depth
   *	@sdev: SCSI device to configure queue depth for
   *	@queue_depth: new queue depth
   *	@reason: calling context

   *

   *	libsas and libata have different approaches for associating a sdev to
   *	its ata_port.

   *

   */

  int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
  			     int queue_depth, int reason)

  {

  	struct ata_device *dev;

  	unsigned long flags;

  	if (reason != SCSI_QDEPTH_DEFAULT)
  		return -EOPNOTSUPP;

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

  		return sdev->queue_depth;
  
  	dev = ata_scsi_find_dev(ap, sdev);
  	if (!dev || !ata_dev_enabled(dev))
  		return sdev->queue_depth;

  	/* NCQ enabled? */

  	spin_lock_irqsave(ap->lock, flags);

  	dev->flags &= ~ATA_DFLAG_NCQ_OFF;
  	if (queue_depth == 1 || !ata_ncq_enabled(dev)) {

  		dev->flags |= ATA_DFLAG_NCQ_OFF;

  		queue_depth = 1;
  	}

  	spin_unlock_irqrestore(ap->lock, flags);

  	/* limit and apply queue depth */
  	queue_depth = min(queue_depth, sdev->host->can_queue);
  	queue_depth = min(queue_depth, ata_id_queue_depth(dev->id));
  	queue_depth = min(queue_depth, ATA_MAX_QUEUE - 1);
  
  	if (sdev->queue_depth == queue_depth)
  		return -EINVAL;
  
  	scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, queue_depth);

  	return queue_depth;
  }
  
  /**

   *	ata_scsi_change_queue_depth - SCSI callback for queue depth config
   *	@sdev: SCSI device to configure queue depth for
   *	@queue_depth: new queue depth
   *	@reason: calling context
   *
   *	This is libata standard hostt->change_queue_depth callback.
   *	SCSI will call into this callback when user tries to set queue
   *	depth via sysfs.
   *
   *	LOCKING:
   *	SCSI layer (we don't care)
   *
   *	RETURNS:
   *	Newly configured queue depth.
   */
  int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth,
  				int reason)
  {
  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  
  	return __ata_change_queue_depth(ap, sdev, queue_depth, reason);
  }
  
  /**

   *	ata_scsi_start_stop_xlat - Translate SCSI START STOP UNIT command
   *	@qc: Storage for translated ATA taskfile

   *
   *	Sets up an ATA taskfile to issue STANDBY (to stop) or READ VERIFY
   *	(to start). Perhaps these commands should be preceded by
   *	CHECK POWER MODE to see what power mode the device is already in.
   *	[See SAT revision 5 at www.t10.org]
   *
   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   *
   *	RETURNS:
   *	Zero on success, non-zero on error.
   */

  static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc)

  {

  	struct scsi_cmnd *scmd = qc->scsicmd;

  	struct ata_taskfile *tf = &qc->tf;

  	const u8 *cdb = scmd->cmnd;

  	if (scmd->cmd_len < 5)
  		goto invalid_fld;

  	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
  	tf->protocol = ATA_PROT_NODATA;

  	if (cdb[1] & 0x1) {

  		;	/* ignore IMMED bit, violates sat-r05 */
  	}

  	if (cdb[4] & 0x2)

  		goto invalid_fld;       /* LOEJ bit set not supported */

  	if (((cdb[4] >> 4) & 0xf) != 0)

  		goto invalid_fld;       /* power conditions not supported */

  	if (cdb[4] & 0x1) {

  		tf->nsect = 1;	/* 1 sector, lba=0 */

  
  		if (qc->dev->flags & ATA_DFLAG_LBA) {

  			tf->flags |= ATA_TFLAG_LBA;

  
  			tf->lbah = 0x0;
  			tf->lbam = 0x0;
  			tf->lbal = 0x0;
  			tf->device |= ATA_LBA;
  		} else {
  			/* CHS */
  			tf->lbal = 0x1; /* sect */
  			tf->lbam = 0x0; /* cyl low */
  			tf->lbah = 0x0; /* cyl high */
  		}

  		tf->command = ATA_CMD_VERIFY;	/* READ VERIFY */

  	} else {

  		/* Some odd clown BIOSen issue spindown on power off (ACPI S4
  		 * or S5) causing some drives to spin up and down again.
  		 */
  		if ((qc->ap->flags & ATA_FLAG_NO_POWEROFF_SPINDOWN) &&
  		    system_state == SYSTEM_POWER_OFF)
  			goto skip;
  
  		if ((qc->ap->flags & ATA_FLAG_NO_HIBERNATE_SPINDOWN) &&
  		     system_entering_hibernation())
  			goto skip;

  		/* Issue ATA STANDBY IMMEDIATE command */
  		tf->command = ATA_CMD_STANDBYNOW1;

  	}

  	/*
  	 * Standby and Idle condition timers could be implemented but that
  	 * would require libata to implement the Power condition mode page
  	 * and allow the user to change it. Changing mode pages requires
  	 * MODE SELECT to be implemented.
  	 */
  
  	return 0;

   invalid_fld:

  	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);

  	/* "Invalid field in cbd" */
  	return 1;

   skip:
  	scmd->result = SAM_STAT_GOOD;
  	return 1;

  }
  
  
  /**

   *	ata_scsi_flush_xlat - Translate SCSI SYNCHRONIZE CACHE command
   *	@qc: Storage for translated ATA taskfile

   *
   *	Sets up an ATA taskfile to issue FLUSH CACHE or
   *	FLUSH CACHE EXT.
   *
   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   *
   *	RETURNS:
   *	Zero on success, non-zero on error.
   */

  static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc)

  {
  	struct ata_taskfile *tf = &qc->tf;
  
  	tf->flags |= ATA_TFLAG_DEVICE;
  	tf->protocol = ATA_PROT_NODATA;

  	if (qc->dev->flags & ATA_DFLAG_FLUSH_EXT)

  		tf->command = ATA_CMD_FLUSH_EXT;
  	else
  		tf->command = ATA_CMD_FLUSH;

  	/* flush is critical for IO integrity, consider it an IO command */
  	qc->flags |= ATA_QCFLAG_IO;

  	return 0;
  }
  
  /**

   *	scsi_6_lba_len - Get LBA and transfer length

   *	@cdb: SCSI command to translate

   *
   *	Calculate LBA and transfer length for 6-byte commands.
   *
   *	RETURNS:
   *	@plba: the LBA
   *	@plen: the transfer length
   */

  static void scsi_6_lba_len(const u8 *cdb, u64 *plba, u32 *plen)

  {
  	u64 lba = 0;

  	u32 len;

  
  	VPRINTK("six-byte command
  ");

  	lba |= ((u64)(cdb[1] & 0x1f)) << 16;

  	lba |= ((u64)cdb[2]) << 8;
  	lba |= ((u64)cdb[3]);

  	len = cdb[4];

  
  	*plba = lba;
  	*plen = len;
  }
  
  /**
   *	scsi_10_lba_len - Get LBA and transfer length

   *	@cdb: SCSI command to translate

   *
   *	Calculate LBA and transfer length for 10-byte commands.
   *
   *	RETURNS:
   *	@plba: the LBA
   *	@plen: the transfer length
   */

  static void scsi_10_lba_len(const u8 *cdb, u64 *plba, u32 *plen)

  {
  	u64 lba = 0;
  	u32 len = 0;
  
  	VPRINTK("ten-byte command
  ");

  	lba |= ((u64)cdb[2]) << 24;
  	lba |= ((u64)cdb[3]) << 16;
  	lba |= ((u64)cdb[4]) << 8;
  	lba |= ((u64)cdb[5]);

  	len |= ((u32)cdb[7]) << 8;
  	len |= ((u32)cdb[8]);

  
  	*plba = lba;
  	*plen = len;
  }
  
  /**
   *	scsi_16_lba_len - Get LBA and transfer length

   *	@cdb: SCSI command to translate

   *
   *	Calculate LBA and transfer length for 16-byte commands.
   *
   *	RETURNS:
   *	@plba: the LBA
   *	@plen: the transfer length
   */

  static void scsi_16_lba_len(const u8 *cdb, u64 *plba, u32 *plen)

  {
  	u64 lba = 0;
  	u32 len = 0;
  
  	VPRINTK("sixteen-byte command
  ");

  	lba |= ((u64)cdb[2]) << 56;
  	lba |= ((u64)cdb[3]) << 48;
  	lba |= ((u64)cdb[4]) << 40;
  	lba |= ((u64)cdb[5]) << 32;
  	lba |= ((u64)cdb[6]) << 24;
  	lba |= ((u64)cdb[7]) << 16;
  	lba |= ((u64)cdb[8]) << 8;
  	lba |= ((u64)cdb[9]);

  	len |= ((u32)cdb[10]) << 24;
  	len |= ((u32)cdb[11]) << 16;
  	len |= ((u32)cdb[12]) << 8;
  	len |= ((u32)cdb[13]);

  
  	*plba = lba;
  	*plen = len;
  }
  
  /**

   *	ata_scsi_verify_xlat - Translate SCSI VERIFY command into an ATA one
   *	@qc: Storage for translated ATA taskfile

   *
   *	Converts SCSI VERIFY command to an ATA READ VERIFY command.
   *
   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   *
   *	RETURNS:
   *	Zero on success, non-zero on error.
   */

  static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc)

  {

  	struct scsi_cmnd *scmd = qc->scsicmd;

  	struct ata_taskfile *tf = &qc->tf;

  	struct ata_device *dev = qc->dev;

  	u64 dev_sectors = qc->dev->n_sectors;

  	const u8 *cdb = scmd->cmnd;

  	u64 block;
  	u32 n_block;

  
  	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
  	tf->protocol = ATA_PROT_NODATA;

  	if (cdb[0] == VERIFY) {
  		if (scmd->cmd_len < 10)
  			goto invalid_fld;

  		scsi_10_lba_len(cdb, &block, &n_block);

  	} else if (cdb[0] == VERIFY_16) {
  		if (scmd->cmd_len < 16)
  			goto invalid_fld;

  		scsi_16_lba_len(cdb, &block, &n_block);

  	} else

  		goto invalid_fld;

  	if (!n_block)

  		goto nothing_to_do;

  	if (block >= dev_sectors)

  		goto out_of_range;

  	if ((block + n_block) > dev_sectors)

  		goto out_of_range;

  	if (dev->flags & ATA_DFLAG_LBA) {
  		tf->flags |= ATA_TFLAG_LBA;

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

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

  			tf->command = ATA_CMD_VERIFY_EXT;

  			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 */
  			goto out_of_range;

  
  		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;

  		if (!lba_28_ok(block, n_block))
  			goto out_of_range;

  		/* 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
  ",
  			(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))

  			goto out_of_range;

  		tf->command = ATA_CMD_VERIFY;
  		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;

  
  invalid_fld:

  	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);

  	/* "Invalid field in cbd" */
  	return 1;
  
  out_of_range:

  	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x21, 0x0);

  	/* "Logical Block Address out of range" */
  	return 1;
  
  nothing_to_do:

  	scmd->result = SAM_STAT_GOOD;

  	return 1;

  }
  
  /**
   *	ata_scsi_rw_xlat - Translate SCSI r/w command into an ATA one
   *	@qc: Storage for translated ATA taskfile

   *
   *	Converts any of six SCSI read/write commands into the
   *	ATA counterpart, including starting sector (LBA),
   *	sector count, and taking into account the device's LBA48
   *	support.
   *
   *	Commands %READ_6, %READ_10, %READ_16, %WRITE_6, %WRITE_10, and
   *	%WRITE_16 are currently supported.
   *
   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   *
   *	RETURNS:
   *	Zero on success, non-zero on error.
   */

  static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)

  {

  	struct scsi_cmnd *scmd = qc->scsicmd;

  	const u8 *cdb = scmd->cmnd;

  	unsigned int tf_flags = 0;

  	u64 block;
  	u32 n_block;

  	int rc;

  	if (cdb[0] == WRITE_10 || cdb[0] == WRITE_6 || cdb[0] == WRITE_16)

  		tf_flags |= ATA_TFLAG_WRITE;

  	/* Calculate the SCSI LBA, transfer length and FUA. */

  	switch (cdb[0]) {

  	case READ_10:
  	case WRITE_10:

  		if (unlikely(scmd->cmd_len < 10))
  			goto invalid_fld;

  		scsi_10_lba_len(cdb, &block, &n_block);
  		if (unlikely(cdb[1] & (1 << 3)))

  			tf_flags |= ATA_TFLAG_FUA;

  		break;
  	case READ_6:
  	case WRITE_6:

  		if (unlikely(scmd->cmd_len < 6))
  			goto invalid_fld;

  		scsi_6_lba_len(cdb, &block, &n_block);

  
  		/* for 6-byte r/w commands, transfer length 0
  		 * means 256 blocks of data, not 0 block.
  		 */

  		if (!n_block)
  			n_block = 256;

  		break;
  	case READ_16:
  	case WRITE_16:

  		if (unlikely(scmd->cmd_len < 16))
  			goto invalid_fld;

  		scsi_16_lba_len(cdb, &block, &n_block);
  		if (unlikely(cdb[1] & (1 << 3)))

  			tf_flags |= ATA_TFLAG_FUA;

  		break;
  	default:

  		DPRINTK("no-byte command
  ");

  		goto invalid_fld;

  	}

  	/* Check and compose ATA command */
  	if (!n_block)

  		/* For 10-byte and 16-byte SCSI R/W commands, transfer
  		 * length 0 means transfer 0 block of data.
  		 * However, for ATA R/W commands, sector count 0 means
  		 * 256 or 65536 sectors, not 0 sectors as in SCSI.

  		 *
  		 * WARNING: one or two older ATA drives treat 0 as 0...

  		 */

  		goto nothing_to_do;

  	qc->flags |= ATA_QCFLAG_IO;

  	qc->nbytes = n_block * scmd->device->sector_size;

  	rc = ata_build_rw_tf(&qc->tf, qc->dev, block, n_block, tf_flags,
  			     qc->tag);
  	if (likely(rc == 0))
  		return 0;

  	if (rc == -ERANGE)
  		goto out_of_range;
  	/* treat all other errors as -EINVAL, fall through */

  invalid_fld:

  	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);

  	/* "Invalid field in cbd" */
  	return 1;
  
  out_of_range:

  	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x21, 0x0);

  	/* "Logical Block Address out of range" */
  	return 1;
  
  nothing_to_do:

  	scmd->result = SAM_STAT_GOOD;

  	return 1;

  }

  static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)

  {

  	struct ata_port *ap = qc->ap;

  	struct scsi_cmnd *cmd = qc->scsicmd;

  	u8 *cdb = cmd->cmnd;

  	int need_sense = (qc->err_mask != 0);

  
  	/* For ATA pass thru (SAT) commands, generate a sense block if
  	 * user mandated it or if there's an error.  Note that if we
  	 * generate because the user forced us to, a check condition
  	 * is generated and the ATA register values are returned
  	 * whether the command completed successfully or not. If there
  	 * was no error, SK, ASC and ASCQ will all be zero.
  	 */

  	if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) &&

  	    ((cdb[2] & 0x20) || need_sense)) {

  		ata_gen_passthru_sense(qc);

  	} else {
  		if (!need_sense) {
  			cmd->result = SAM_STAT_GOOD;
  		} else {
  			/* TODO: decide which descriptor format to use
  			 * for 48b LBA devices and call that here
  			 * instead of the fixed desc, which is only
  			 * good for smaller LBA (and maybe CHS?)
  			 * devices.
  			 */

  			ata_gen_ata_sense(qc);

  		}
  	}

  	if (need_sense && !ap->ops->error_handler)

  		ata_dump_status(ap->print_id, &qc->result_tf);

  
  	qc->scsidone(cmd);

  	ata_qc_free(qc);

  }
  
  /**
   *	ata_scsi_translate - Translate then issue SCSI command to ATA device

   *	@dev: ATA device to which the command is addressed
   *	@cmd: SCSI command to execute

   *	@xlat_func: Actor which translates @cmd to an ATA taskfile
   *
   *	Our ->queuecommand() function has decided that the SCSI
   *	command issued can be directly translated into an ATA
   *	command, rather than handled internally.
   *
   *	This function sets up an ata_queued_cmd structure for the
   *	SCSI command, and sends that ata_queued_cmd to the hardware.
   *

   *	The xlat_func argument (actor) returns 0 if ready to execute
   *	ATA command, else 1 to finish translation. If 1 is returned
   *	then cmd->result (and possibly cmd->sense_buffer) are assumed
   *	to be set reflecting an error condition or clean (early)
   *	termination.
   *

   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   *
   *	RETURNS:
   *	0 on success, SCSI_ML_QUEUE_DEVICE_BUSY if the command
   *	needs to be deferred.

   */

  static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,

  			      ata_xlat_func_t xlat_func)

  {

  	struct ata_port *ap = dev->link->ap;

  	struct ata_queued_cmd *qc;

  	int rc;

  
  	VPRINTK("ENTER
  ");

  	qc = ata_scsi_qc_new(dev, cmd);

  	if (!qc)

  		goto err_mem;

  
  	/* data is present; dma-map it */

  	if (cmd->sc_data_direction == DMA_FROM_DEVICE ||
  	    cmd->sc_data_direction == DMA_TO_DEVICE) {

  		if (unlikely(scsi_bufflen(cmd) < 1)) {

  			ata_dev_warn(dev, "WARNING: zero len r/w req
  ");

  			goto err_did;

  		}

  		ata_sg_init(qc, scsi_sglist(cmd), scsi_sg_count(cmd));

  
  		qc->dma_dir = cmd->sc_data_direction;
  	}
  
  	qc->complete_fn = ata_scsi_qc_complete;

  	if (xlat_func(qc))

  		goto early_finish;

  	if (ap->ops->qc_defer) {
  		if ((rc = ap->ops->qc_defer(qc)))
  			goto defer;
  	}

  	/* select device, send command to hardware */

  	ata_qc_issue(qc);

  
  	VPRINTK("EXIT
  ");

  	return 0;

  early_finish:

  	ata_qc_free(qc);

  	cmd->scsi_done(cmd);

  	DPRINTK("EXIT - early finish (good or error)
  ");

  	return 0;

  
  err_did:

  	ata_qc_free(qc);

  	cmd->result = (DID_ERROR << 16);

  	cmd->scsi_done(cmd);

  err_mem:

  	DPRINTK("EXIT - internal
  ");

  	return 0;

  
  defer:

  	ata_qc_free(qc);

  	DPRINTK("EXIT - defer
  ");

  	if (rc == ATA_DEFER_LINK)
  		return SCSI_MLQUEUE_DEVICE_BUSY;
  	else
  		return SCSI_MLQUEUE_HOST_BUSY;

  }
  
  /**
   *	ata_scsi_rbuf_get - Map response buffer.

   *	@cmd: SCSI command containing buffer to be mapped.

   *	@flags: unsigned long variable to store irq enable status
   *	@copy_in: copy in from user buffer

   *

   *	Prepare buffer for simulated SCSI commands.

   *
   *	LOCKING:

   *	spin_lock_irqsave(ata_scsi_rbuf_lock) on success

   *
   *	RETURNS:

   *	Pointer to response buffer.

   */

  static void *ata_scsi_rbuf_get(struct scsi_cmnd *cmd, bool copy_in,
  			       unsigned long *flags)

  {

  	spin_lock_irqsave(&ata_scsi_rbuf_lock, *flags);

  	memset(ata_scsi_rbuf, 0, ATA_SCSI_RBUF_SIZE);
  	if (copy_in)
  		sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
  				  ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);
  	return ata_scsi_rbuf;

  }
  
  /**
   *	ata_scsi_rbuf_put - Unmap response buffer.
   *	@cmd: SCSI command containing buffer to be unmapped.

   *	@copy_out: copy out result
   *	@flags: @flags passed to ata_scsi_rbuf_get()

   *

   *	Returns rbuf buffer.  The result is copied to @cmd's buffer if
   *	@copy_back is true.

   *
   *	LOCKING:

   *	Unlocks ata_scsi_rbuf_lock.

   */

  static inline void ata_scsi_rbuf_put(struct scsi_cmnd *cmd, bool copy_out,
  				     unsigned long *flags)

  {

  	if (copy_out)
  		sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
  				    ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);
  	spin_unlock_irqrestore(&ata_scsi_rbuf_lock, *flags);

  }
  
  /**
   *	ata_scsi_rbuf_fill - wrapper for SCSI command simulators
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@actor: Callback hook for desired SCSI command simulator
   *
   *	Takes care of the hard work of simulating a SCSI command...
   *	Mapping the response buffer, calling the command's handler,
   *	and handling the handler's return value.  This return value
   *	indicates whether the handler wishes the SCSI command to be

   *	completed successfully (0), or not (in which case cmd->result
   *	and sense buffer are assumed to be set).

   *
   *	LOCKING:

   *	spin_lock_irqsave(host lock)

   */

  static void ata_scsi_rbuf_fill(struct ata_scsi_args *args,

  		unsigned int (*actor)(struct ata_scsi_args *args, u8 *rbuf))