text: /*
   *  libata-scsi.c - helper library for ATA
   *
   *  Maintained by:  Tejun Heo <tj@kernel.org>
   *    		    Please ALWAYS copy linux-ide@vger.kernel.org
   *		    on emails.
   *
   *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
   *  Copyright 2003-2004 Jeff Garzik
   *
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2, or (at your option)
   *  any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; see the file COPYING.  If not, write to
   *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   *
   *  libata documentation is available via 'make {ps|pdf}docs',
   *  as Documentation/driver-api/libata.rst
   *
   *  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 <linux/ioprio.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 *device,
  				  struct device_attribute *attr,
  				  const char *buf, size_t count)
  {
  	struct Scsi_Host *shost = class_to_shost(device);
  	struct ata_port *ap = ata_shost_to_port(shost);
  	struct ata_link *link;
  	struct ata_device *dev;
  	enum ata_lpm_policy policy;
  	unsigned long flags;
  
  	/* UNKNOWN is internal state, iterate from MAX_POWER */
  	for (policy = ATA_LPM_MAX_POWER;
  	     policy < ARRAY_SIZE(ata_lpm_policy_names); policy++) {
  		const char *name = ata_lpm_policy_names[policy];
  
  		if (strncmp(name, buf, strlen(name)) == 0)
  			break;
  	}
  	if (policy == ARRAY_SIZE(ata_lpm_policy_names))
  		return -EINVAL;
  
  	spin_lock_irqsave(ap->lock, flags);
  
  	ata_for_each_link(link, ap, EDGE) {
  		ata_for_each_dev(dev, &ap->link, ENABLED) {
  			if (dev->horkage & ATA_HORKAGE_NOLPM) {
  				count = -EOPNOTSUPP;
  				goto out_unlock;
  			}
  		}
  	}
  
  	ap->target_lpm_policy = policy;
  	ata_port_schedule_eh(ap);
  out_unlock:
  	spin_unlock_irqrestore(ap->lock, flags);
  	return count;
  }
  
  static ssize_t ata_scsi_lpm_show(struct device *dev,
  				 struct device_attribute *attr, char *buf)
  {
  	struct Scsi_Host *shost = class_to_shost(dev);
  	struct ata_port *ap = ata_shost_to_port(shost);
  
  	if (ap->target_lpm_policy >= ARRAY_SIZE(ata_lpm_policy_names))
  		return -EINVAL;
  
  	return snprintf(buf, PAGE_SIZE, "%s\n",
  			ata_lpm_policy_names[ap->target_lpm_policy]);
  }
  DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
  	    ata_scsi_lpm_show, ata_scsi_lpm_store);
  EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
  
  static ssize_t ata_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 now;
  	unsigned int uninitialized_var(msecs);
  	int rc = 0;
  
  	ap = ata_shost_to_port(sdev->host);
  
  	spin_lock_irq(ap->lock);
  	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\n", 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 = kstrtol(buf, 10, &input);
  	if (rc)
  		return rc;
  	if (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 &&
  	    dev->class != ATA_DEV_ZAC) {
  		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 ssize_t ata_ncq_prio_enable_show(struct device *device,
  					struct device_attribute *attr,
  					char *buf)
  {
  	struct scsi_device *sdev = to_scsi_device(device);
  	struct ata_port *ap;
  	struct ata_device *dev;
  	bool ncq_prio_enable;
  	int rc = 0;
  
  	ap = ata_shost_to_port(sdev->host);
  
  	spin_lock_irq(ap->lock);
  	dev = ata_scsi_find_dev(ap, sdev);
  	if (!dev) {
  		rc = -ENODEV;
  		goto unlock;
  	}
  
  	ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE;
  
  unlock:
  	spin_unlock_irq(ap->lock);
  
  	return rc ? rc : snprintf(buf, 20, "%u\n", ncq_prio_enable);
  }
  
  static ssize_t ata_ncq_prio_enable_store(struct device *device,
  					 struct device_attribute *attr,
  					 const char *buf, size_t len)
  {
  	struct scsi_device *sdev = to_scsi_device(device);
  	struct ata_port *ap;
  	struct ata_device *dev;
  	long int input;
  	int rc;
  
  	rc = kstrtol(buf, 10, &input);
  	if (rc)
  		return rc;
  	if ((input < 0) || (input > 1))
  		return -EINVAL;
  
  	ap = ata_shost_to_port(sdev->host);
  	dev = ata_scsi_find_dev(ap, sdev);
  	if (unlikely(!dev))
  		return  -ENODEV;
  
  	spin_lock_irq(ap->lock);
  	if (input)
  		dev->flags |= ATA_DFLAG_NCQ_PRIO_ENABLE;
  	else
  		dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;
  
  	dev->link->eh_info.action |= ATA_EH_REVALIDATE;
  	dev->link->eh_info.flags |= ATA_EHI_QUIET;
  	ata_port_schedule_eh(ap);
  	spin_unlock_irq(ap->lock);
  
  	ata_port_wait_eh(ap);
  
  	if (input) {
  		spin_lock_irq(ap->lock);
  		if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {
  			dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;
  			rc = -EIO;
  		}
  		spin_unlock_irq(ap->lock);
  	}
  
  	return rc ? rc : len;
  }
  
  DEVICE_ATTR(ncq_prio_enable, S_IRUGO | S_IWUSR,
  	    ata_ncq_prio_enable_show, ata_ncq_prio_enable_store);
  EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_enable);
  
  void ata_scsi_set_sense(struct ata_device *dev, struct scsi_cmnd *cmd,
  			u8 sk, u8 asc, u8 ascq)
  {
  	bool d_sense = (dev->flags & ATA_DFLAG_D_SENSE);
  
  	if (!cmd)
  		return;
  
  	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
  
  	scsi_build_sense_buffer(d_sense, cmd->sense_buffer, sk, asc, ascq);
  }
  
  void ata_scsi_set_sense_information(struct ata_device *dev,
  				    struct scsi_cmnd *cmd,
  				    const struct ata_taskfile *tf)
  {
  	u64 information;
  
  	if (!cmd)
  		return;
  
  	information = ata_tf_read_block(tf, dev);
  	if (information == U64_MAX)
  		return;
  
  	scsi_set_sense_information(cmd->sense_buffer,
  				   SCSI_SENSE_BUFFERSIZE, information);
  }
  
  static void ata_scsi_set_invalid_field(struct ata_device *dev,
  				       struct scsi_cmnd *cmd, u16 field, u8 bit)
  {
  	ata_scsi_set_sense(dev, cmd, ILLEGAL_REQUEST, 0x24, 0x0);
  	/* "Invalid field in CDB" */
  	scsi_set_sense_field_pointer(cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE,
  				     field, bit, 1);
  }
  
  static void ata_scsi_set_invalid_parameter(struct ata_device *dev,
  					   struct scsi_cmnd *cmd, u16 field)
  {
  	/* "Invalid field in parameter list" */
  	ata_scsi_set_sense(dev, cmd, ILLEGAL_REQUEST, 0x26, 0x0);
  	scsi_set_sense_field_pointer(cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE,
  				     field, 0xff, 0);
  }
  
  static ssize_t
  ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
  			  const char *buf, size_t count)
  {
  	struct Scsi_Host *shost = class_to_shost(dev);
  	struct ata_port *ap = ata_shost_to_port(shost);
  	if (ap->ops->em_store && (ap->flags & ATA_FLAG_EM))
  		return ap->ops->em_store(ap, buf, count);
  	return -EINVAL;
  }
  
  static ssize_t
  ata_scsi_em_message_show(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct Scsi_Host *shost = class_to_shost(dev);
  	struct ata_port *ap = ata_shost_to_port(shost);
  
  	if (ap->ops->em_show && (ap->flags & ATA_FLAG_EM))
  		return ap->ops->em_show(ap, buf);
  	return -EINVAL;
  }
  DEVICE_ATTR(em_message, S_IRUGO | S_IWUSR,
  		ata_scsi_em_message_show, ata_scsi_em_message_store);
  EXPORT_SYMBOL_GPL(dev_attr_em_message);
  
  static ssize_t
  ata_scsi_em_message_type_show(struct device *dev, struct device_attribute *attr,
  			      char *buf)
  {
  	struct Scsi_Host *shost = class_to_shost(dev);
  	struct ata_port *ap = ata_shost_to_port(shost);
  
  	return snprintf(buf, 23, "%d\n", ap->em_message_type);
  }
  DEVICE_ATTR(em_message_type, S_IRUGO,
  		  ata_scsi_em_message_type_show, NULL);
  EXPORT_SYMBOL_GPL(dev_attr_em_message_type);
  
  static ssize_t
  ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct scsi_device *sdev = to_scsi_device(dev);
  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
  
  	if (atadev && ap->ops->sw_activity_show &&
  	    (ap->flags & ATA_FLAG_SW_ACTIVITY))
  		return ap->ops->sw_activity_show(atadev, buf);
  	return -EINVAL;
  }
  
  static ssize_t
  ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
  	const char *buf, size_t count)
  {
  	struct scsi_device *sdev = to_scsi_device(dev);
  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
  	enum sw_activity val;
  	int rc;
  
  	if (atadev && ap->ops->sw_activity_store &&
  	    (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
  		val = simple_strtoul(buf, NULL, 0);
  		switch (val) {
  		case OFF: case BLINK_ON: case BLINK_OFF:
  			rc = ap->ops->sw_activity_store(atadev, val);
  			if (!rc)
  				return count;
  			else
  				return rc;
  		}
  	}
  	return -EINVAL;
  }
  DEVICE_ATTR(sw_activity, S_IWUSR | S_IRUGO, ata_scsi_activity_show,
  			ata_scsi_activity_store);
  EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
  
  struct device_attribute *ata_common_sdev_attrs[] = {
  	&dev_attr_unload_heads,
  	&dev_attr_ncq_prio_enable,
  	NULL
  };
  EXPORT_SYMBOL_GPL(ata_common_sdev_attrs);
  
  /**
   *	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;
  	struct scsi_sense_hdr sshdr;
  	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, &sshdr, (10*HZ), 5, 0, 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) {
  			if (sshdr.sense_key == RECOVERED_ERROR &&
  			    sshdr.asc == 0 && sshdr.ascq == 0x1d)
  				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;
  	struct scsi_sense_hdr sshdr;
  	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, &sshdr, (10*HZ), 5, 0, 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) {
  			if (sshdr.sense_key == RECOVERED_ERROR &&
  			    sshdr.asc == 0 && sshdr.ascq == 0x1d)
  				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)
  {
  	unsigned long val;
  	int rc = -EINVAL;
  	unsigned long flags;
  
  	switch (cmd) {
  	case HDIO_GET_32BIT:
  		spin_lock_irqsave(ap->lock, flags);
  		val = ata_ioc32(ap);
  		spin_unlock_irqrestore(ap->lock, flags);
  		return put_user(val, (unsigned long __user *)arg);
  
  	case HDIO_SET_32BIT:
  		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, cmd->request->tag);
  	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;
  
  	pr_warn("ata%u: status=0x%02x { ", id, stat);
  	if (stat & ATA_BUSY) {
  		pr_cont("Busy }\n");	/* Data is not valid in this case */
  	} else {
  		if (stat & ATA_DRDY)	pr_cont("DriveReady ");
  		if (stat & ATA_DF)	pr_cont("DeviceFault ");
  		if (stat & ATA_DSC)	pr_cont("SeekComplete ");
  		if (stat & ATA_DRQ)	pr_cont("DataRequest ");
  		if (stat & ATA_CORR)	pr_cont("CorrectedError ");
  		if (stat & ATA_SENSE)	pr_cont("Sense ");
  		if (stat & ATA_ERR)	pr_cont("Error ");
  		pr_cont("}\n");
  
  		if (err) {
  			pr_warn("ata%u: error=0x%02x { ", id, err);
  			if (err & ATA_ABORTED)	pr_cont("DriveStatusError ");
  			if (err & ATA_ICRC) {
  				if (err & ATA_ABORTED)
  						pr_cont("BadCRC ");
  				else		pr_cont("Sector ");
  			}
  			if (err & ATA_UNC)	pr_cont("UncorrectableError ");
  			if (err & ATA_IDNF)	pr_cont("SectorIdNotFound ");
  			if (err & ATA_TRK0NF)	pr_cont("TrackZeroNotFound ");
  			if (err & ATA_AMNF)	pr_cont("AddrMarkNotFound ");
  			pr_cont("}\n");
  		}
  	}
  }
  
  /**
   *	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 for data field
  		/* TRK0 - Track 0 not found */
  		{0x02,		HARDWARE_ERROR, 0x00, 0x00},
  			// Hardware error
  		/* Abort: 0x04 is not translated here, see below */
  		/* Media change request */
  		{0x08,		NOT_READY, 0x04, 0x00},
  			// FIXME: faking offline
  		/* SRV/IDNF - ID not found */
  		{0x10,		ILLEGAL_REQUEST, 0x21, 0x00},
  			// Logical address out of range
  		/* MC - Media Changed */
  		{0x20,		UNIT_ATTENTION, 0x28, 0x00},
  			// Not ready to ready change, medium may have changed
  		/* ECC - Uncorrectable ECC error */
  		{0x40,		MEDIUM_ERROR, 0x11, 0x04},
  			// 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
  		{0x40,		ILLEGAL_REQUEST, 0x21, 0x04},
  		// Device ready, unaligned write command
  		{0x20,		HARDWARE_ERROR,  0x44, 0x00},
  		// Device fault, internal target failure
  		{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;
  			}
  		}
  	}
  
  	/*
  	 * Fall back to interpreting status bits.  Note that if the drv_err
  	 * has only the ABRT bit set, we decode drv_stat.  ABRT by itself
  	 * is not descriptive enough.
  	 */
  	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;
  		}
  	}
  
  	/*
  	 * 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)
  		pr_err("ata%u: translated ATA stat/err 0x%02x/%02x to SCSI SK/ASC/ASCQ 0x%x/%02x/%02x\n",
  		       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. If there was no error, we get the request from an ATA
   *	passthrough command, so we use the following sense data:
   *	sk = RECOVERED ERROR
   *	asc,ascq = ATA PASS-THROUGH INFORMATION AVAILABLE
   *      
   *
   *	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;
  	u8 sense_key, asc, ascq;
  
  	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,
  				   &sense_key, &asc, &ascq, verbose);
  		ata_scsi_set_sense(qc->dev, cmd, sense_key, asc, ascq);
  	} else {
  		/*
  		 * ATA PASS-THROUGH INFORMATION AVAILABLE
  		 * Always in descriptor format sense.
  		 */
  		scsi_build_sense_buffer(1, cmd->sense_buffer,
  					RECOVERED_ERROR, 0, 0x1D);
  	}
  
  	if ((cmd->sense_buffer[0] & 0x7f) >= 0x72) {
  		u8 len;
  
  		/* descriptor format */
  		len = sb[7];
  		desc = (char *)scsi_sense_desc_find(sb, len + 8, 9);
  		if (!desc) {
  			if (SCSI_SENSE_BUFFERSIZE < len + 14)
  				return;
  			sb[7] = len + 14;
  			desc = sb + 8 + len;
  		}
  		desc[0] = 9;
  		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;
  		}
  	} else {
  		/* Fixed sense format */
  		desc[0] = tf->feature;
  		desc[1] = tf->command; /* status */
  		desc[2] = tf->device;
  		desc[3] = tf->nsect;
  		desc[7] = 0;
  		if (tf->flags & ATA_TFLAG_LBA48)  {
  			desc[8] |= 0x80;
  			if (tf->hob_nsect)
  				desc[8] |= 0x40;
  			if (tf->hob_lbal || tf->hob_lbam || tf->hob_lbah)
  				desc[8] |= 0x20;
  		}
  		desc[9] = tf->lbal;
  		desc[10] = tf->lbam;
  		desc[11] = tf->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;
  	int verbose = qc->ap->ops->error_handler == NULL;
  	u64 block;
  	u8 sense_key, asc, ascq;
  
  	memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
  
  	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
  
  	if (ata_dev_disabled(dev)) {
  		/* Device disabled after error recovery */
  		/* LOGICAL UNIT NOT READY, HARD RESET REQUIRED */
  		ata_scsi_set_sense(dev, cmd, NOT_READY, 0x04, 0x21);
  		return;
  	}
  	/* 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,
  				   &sense_key, &asc, &ascq, verbose);
  		ata_scsi_set_sense(dev, cmd, sense_key, asc, ascq);
  	} else {
  		/* Could not decode error */
  		ata_dev_warn(dev, "could not decode error status 0x%x err_mask 0x%x\n",
  			     tf->command, qc->err_mask);
  		ata_scsi_set_sense(dev, cmd, ABORTED_COMMAND, 0, 0);
  		return;
  	}
  
  	block = ata_tf_read_block(&qc->result_tf, dev);
  	if (block == U64_MAX)
  		return;
  
  	scsi_set_sense_information(sb, SCSI_SENSE_BUFFERSIZE, block);
  }
  
  static void ata_scsi_sdev_config(struct scsi_device *sdev)
  {
  	sdev->use_10_for_rw = 1;
  	sdev->use_10_for_ms = 1;
  	sdev->no_write_same = 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 hardware 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(!blk_rq_is_passthrough(rq)))
  		return 0;
  
  	if (!blk_rq_bytes(rq) || op_is_write(req_op(rq)))
  		return 0;
  
  	return atapi_cmd_type(scsi_req(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\n");
  			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\n",
  			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_change_queue_depth(sdev, depth);
  	}
  
  	blk_queue_flush_queueable(q, false);
  
  	if (dev->flags & ATA_DFLAG_TRUSTED)
  		sdev->security_supported = 1;
  
  	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
   *
   *	libsas and libata have different approaches for associating a sdev to
   *	its ata_port.
   *
   */
  int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
  			     int queue_depth)
  {
  	struct ata_device *dev;
  	unsigned long flags;
  
  	if (queue_depth < 1 || queue_depth == sdev->queue_depth)
  		return sdev->queue_depth;
  
  	dev = ata_scsi_find_dev(ap, sdev);
  	if (!dev || !ata_dev_enabled(dev))
  		return sdev->queue_depth;
  
  	/* NCQ enabled? */
  	spin_lock_irqsave(ap->lock, flags);
  	dev->flags &= ~ATA_DFLAG_NCQ_OFF;
  	if (queue_depth == 1 || !ata_ncq_enabled(dev)) {
  		dev->flags |= ATA_DFLAG_NCQ_OFF;
  		queue_depth = 1;
  	}
  	spin_unlock_irqrestore(ap->lock, flags);
  
  	/* limit and apply queue depth */
  	queue_depth = min(queue_depth, sdev->host->can_queue);
  	queue_depth = min(queue_depth, ata_id_queue_depth(dev->id));
  	queue_depth = min(queue_depth, ATA_MAX_QUEUE - 1);
  
  	if (sdev->queue_depth == queue_depth)
  		return -EINVAL;
  
  	return scsi_change_queue_depth(sdev, queue_depth);
  }
  
  /**
   *	ata_scsi_change_queue_depth - SCSI callback for queue depth config
   *	@sdev: SCSI device to configure queue depth for
   *	@queue_depth: new queue depth
   *
   *	This is libata standard hostt->change_queue_depth callback.
   *	SCSI will call into this callback when user tries to set queue
   *	depth via sysfs.
   *
   *	LOCKING:
   *	SCSI layer (we don't care)
   *
   *	RETURNS:
   *	Newly configured queue depth.
   */
  int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
  {
  	struct ata_port *ap = ata_shost_to_port(sdev->host);
  
  	return __ata_change_queue_depth(ap, sdev, queue_depth);
  }
  
  /**
   *	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;
  	u16 fp;
  	u8 bp = 0xff;
  
  	if (scmd->cmd_len < 5) {
  		fp = 4;
  		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) {
  		fp = 4;
  		bp = 1;
  		goto invalid_fld;       /* LOEJ bit set not supported */
  	}
  	if (((cdb[4] >> 4) & 0xf) != 0) {
  		fp = 4;
  		bp = 3;
  		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_invalid_field(qc->dev, scmd, fp, bp);
  	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\n");
  
  	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\n");
  
  	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\n");
  
  	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;
  	u16 fp;
  
  	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
  	tf->protocol = ATA_PROT_NODATA;
  
  	if (cdb[0] == VERIFY) {
  		if (scmd->cmd_len < 10) {
  			fp = 9;
  			goto invalid_fld;
  		}
  		scsi_10_lba_len(cdb, &block, &n_block);
  	} else if (cdb[0] == VERIFY_16) {
  		if (scmd->cmd_len < 16) {
  			fp = 15;
  			goto invalid_fld;
  		}
  		scsi_16_lba_len(cdb, &block, &n_block);
  	} else {
  		fp = 0;
  		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\n",
  			(u32)block, track, cyl, head, sect);
  
  		/* Check whether the converted CHS can fit.
  		   Cylinder: 0-65535
  		   Head: 0-15
  		   Sector: 1-255*/
  		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
  			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_invalid_field(qc->dev, scmd, fp, 0xff);
  	return 1;
  
  out_of_range:
  	ata_scsi_set_sense(qc->dev, 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;
  	struct request *rq = scmd->request;
  	int class = IOPRIO_PRIO_CLASS(req_get_ioprio(rq));
  	unsigned int tf_flags = 0;
  	u64 block;
  	u32 n_block;
  	int rc;
  	u16 fp = 0;
  
  	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)) {
  			fp = 9;
  			goto invalid_fld;
  		}
  		scsi_10_lba_len(cdb, &block, &n_block);
  		if (cdb[1] & (1 << 3))
  			tf_flags |= ATA_TFLAG_FUA;
  		break;
  	case READ_6:
  	case WRITE_6:
  		if (unlikely(scmd->cmd_len < 6)) {
  			fp = 5;
  			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)) {
  			fp = 15;
  			goto invalid_fld;
  		}
  		scsi_16_lba_len(cdb, &block, &n_block);
  		if (cdb[1] & (1 << 3))
  			tf_flags |= ATA_TFLAG_FUA;
  		break;
  	default:
  		DPRINTK("no-byte command\n");
  		fp = 0;
  		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, class);
  
  	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_invalid_field(qc->dev, scmd, fp, 0xff);
  	return 1;
  
  out_of_range:
  	ata_scsi_set_sense(qc->dev, 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_qc_done(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *cmd = qc->scsicmd;
  	void (*done)(struct scsi_cmnd *) = qc->scsidone;
  
  	ata_qc_free(qc);
  	done(cmd);
  }
  
  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 [CK_COND =1], a check
  	 * condition is generated and the ATA register values are returned
  	 * whether the command completed successfully or not. If there
  	 * was no error, we use the following sense data:
  	 * sk = RECOVERED ERROR
  	 * asc,ascq = ATA PASS-THROUGH INFORMATION AVAILABLE
  	 */
  	if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) &&
  	    ((cdb[2] & 0x20) || need_sense))
  		ata_gen_passthru_sense(qc);
  	else if (qc->flags & ATA_QCFLAG_SENSE_VALID)
  		cmd->result = SAM_STAT_CHECK_CONDITION;
  	else if (need_sense)
  		ata_gen_ata_sense(qc);
  	else
  		cmd->result = SAM_STAT_GOOD;
  
  	if (need_sense && !ap->ops->error_handler)
  		ata_dump_status(ap->print_id, &qc->result_tf);
  
  	ata_qc_done(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\n");
  
  	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\n");
  			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\n");
  	return 0;
  
  early_finish:
  	ata_qc_free(qc);
  	cmd->scsi_done(cmd);
  	DPRINTK("EXIT - early finish (good or error)\n");
  	return 0;
  
  err_did:
  	ata_qc_free(qc);
  	cmd->result = (DID_ERROR << 16);
  	cmd->scsi_done(cmd);
  err_mem:
  	DPRINTK("EXIT - internal\n");
  	return 0;
  
  defer:
  	ata_qc_free(qc);
  	DPRINTK("EXIT - defer\n");
  	if (rc == ATA_DEFER_LINK)
  		return SCSI_MLQUEUE_DEVICE_BUSY;
  	else
  		return SCSI_MLQUEUE_HOST_BUSY;
  }
  
  struct ata_scsi_args {
  	struct ata_device	*dev;
  	u16			*id;
  	struct scsi_cmnd	*cmd;
  };
  
  /**
   *	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))
  {
  	u8 *rbuf;
  	unsigned int rc;
  	struct scsi_cmnd *cmd = args->cmd;
  	unsigned long flags;
  
  	rbuf = ata_scsi_rbuf_get(cmd, false, &flags);
  	rc = actor(args, rbuf);
  	ata_scsi_rbuf_put(cmd, rc == 0, &flags);
  
  	if (rc == 0)
  		cmd->result = SAM_STAT_GOOD;
  }
  
  /**
   *	ata_scsiop_inq_std - Simulate INQUIRY command
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Returns standard device identification data associated
   *	with non-VPD INQUIRY command output.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf)
  {
  	const u8 versions[] = {
  		0x00,
  		0x60,	/* SAM-3 (no version claimed) */
  
  		0x03,
  		0x20,	/* SBC-2 (no version claimed) */
  
  		0x03,
  		0x00	/* SPC-3 (no version claimed) */
  	};
  	const u8 versions_zbc[] = {
  		0x00,
  		0xA0,	/* SAM-5 (no version claimed) */
  
  		0x06,
  		0x00,	/* SBC-4 (no version claimed) */
  
  		0x05,
  		0xC0,	/* SPC-5 (no version claimed) */
  
  		0x60,
  		0x24,   /* ZBC r05 */
  	};
  
  	u8 hdr[] = {
  		TYPE_DISK,
  		0,
  		0x5,	/* claim SPC-3 version compatibility */
  		2,
  		95 - 4,
  		0,
  		0,
  		2
  	};
  
  	VPRINTK("ENTER\n");
  
  	/* set scsi removable (RMB) bit per ata bit, or if the
  	 * AHCI port says it's external (Hotplug-capable, eSATA).
  	 */
  	if (ata_id_removable(args->id) ||
  	    (args->dev->link->ap->pflags & ATA_PFLAG_EXTERNAL))
  		hdr[1] |= (1 << 7);
  
  	if (args->dev->class == ATA_DEV_ZAC) {
  		hdr[0] = TYPE_ZBC;
  		hdr[2] = 0x7; /* claim SPC-5 version compatibility */
  	}
  
  	memcpy(rbuf, hdr, sizeof(hdr));
  	memcpy(&rbuf[8], "ATA     ", 8);
  	ata_id_string(args->id, &rbuf[16], ATA_ID_PROD, 16);
  
  	/* From SAT, use last 2 words from fw rev unless they are spaces */
  	ata_id_string(args->id, &rbuf[32], ATA_ID_FW_REV + 2, 4);
  	if (strncmp(&rbuf[32], "    ", 4) == 0)
  		ata_id_string(args->id, &rbuf[32], ATA_ID_FW_REV, 4);
  
  	if (rbuf[32] == 0 || rbuf[32] == ' ')
  		memcpy(&rbuf[32], "n/a ", 4);
  
  	if (ata_id_zoned_cap(args->id) || args->dev->class == ATA_DEV_ZAC)
  		memcpy(rbuf + 58, versions_zbc, sizeof(versions_zbc));
  	else
  		memcpy(rbuf + 58, versions, sizeof(versions));
  
  	return 0;
  }
  
  /**
   *	ata_scsiop_inq_00 - Simulate INQUIRY VPD page 0, list of pages
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Returns list of inquiry VPD pages available.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_inq_00(struct ata_scsi_args *args, u8 *rbuf)
  {
  	int num_pages;
  	const u8 pages[] = {
  		0x00,	/* page 0x00, this page */
  		0x80,	/* page 0x80, unit serial no page */
  		0x83,	/* page 0x83, device ident page */
  		0x89,	/* page 0x89, ata info page */
  		0xb0,	/* page 0xb0, block limits page */
  		0xb1,	/* page 0xb1, block device characteristics page */
  		0xb2,	/* page 0xb2, thin provisioning page */
  		0xb6,	/* page 0xb6, zoned block device characteristics */
  	};
  
  	num_pages = sizeof(pages);
  	if (!(args->dev->flags & ATA_DFLAG_ZAC))
  		num_pages--;
  	rbuf[3] = num_pages;	/* number of supported VPD pages */
  	memcpy(rbuf + 4, pages, num_pages);
  	return 0;
  }
  
  /**
   *	ata_scsiop_inq_80 - Simulate INQUIRY VPD page 80, device serial number
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Returns ATA device serial number.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_inq_80(struct ata_scsi_args *args, u8 *rbuf)
  {
  	const u8 hdr[] = {
  		0,
  		0x80,			/* this page code */
  		0,
  		ATA_ID_SERNO_LEN,	/* page len */
  	};
  
  	memcpy(rbuf, hdr, sizeof(hdr));
  	ata_id_string(args->id, (unsigned char *) &rbuf[4],
  		      ATA_ID_SERNO, ATA_ID_SERNO_LEN);
  	return 0;
  }
  
  /**
   *	ata_scsiop_inq_83 - Simulate INQUIRY VPD page 83, device identity
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Yields two logical unit device identification designators:
   *	 - vendor specific ASCII containing the ATA serial number
   *	 - SAT defined "t10 vendor id based" containing ASCII vendor
   *	   name ("ATA     "), model and serial numbers.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_inq_83(struct ata_scsi_args *args, u8 *rbuf)
  {
  	const int sat_model_serial_desc_len = 68;
  	int num;
  
  	rbuf[1] = 0x83;			/* this page code */
  	num = 4;
  
  	/* piv=0, assoc=lu, code_set=ACSII, designator=vendor */
  	rbuf[num + 0] = 2;
  	rbuf[num + 3] = ATA_ID_SERNO_LEN;
  	num += 4;
  	ata_id_string(args->id, (unsigned char *) rbuf + num,
  		      ATA_ID_SERNO, ATA_ID_SERNO_LEN);
  	num += ATA_ID_SERNO_LEN;
  
  	/* SAT defined lu model and serial numbers descriptor */
  	/* piv=0, assoc=lu, code_set=ACSII, designator=t10 vendor id */
  	rbuf[num + 0] = 2;
  	rbuf[num + 1] = 1;
  	rbuf[num + 3] = sat_model_serial_desc_len;
  	num += 4;
  	memcpy(rbuf + num, "ATA     ", 8);
  	num += 8;
  	ata_id_string(args->id, (unsigned char *) rbuf + num, ATA_ID_PROD,
  		      ATA_ID_PROD_LEN);
  	num += ATA_ID_PROD_LEN;
  	ata_id_string(args->id, (unsigned char *) rbuf + num, ATA_ID_SERNO,
  		      ATA_ID_SERNO_LEN);
  	num += ATA_ID_SERNO_LEN;
  
  	if (ata_id_has_wwn(args->id)) {
  		/* SAT defined lu world wide name */
  		/* piv=0, assoc=lu, code_set=binary, designator=NAA */
  		rbuf[num + 0] = 1;
  		rbuf[num + 1] = 3;
  		rbuf[num + 3] = ATA_ID_WWN_LEN;
  		num += 4;
  		ata_id_string(args->id, (unsigned char *) rbuf + num,
  			      ATA_ID_WWN, ATA_ID_WWN_LEN);
  		num += ATA_ID_WWN_LEN;
  	}
  	rbuf[3] = num - 4;    /* page len (assume less than 256 bytes) */
  	return 0;
  }
  
  /**
   *	ata_scsiop_inq_89 - Simulate INQUIRY VPD page 89, ATA info
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Yields SAT-specified ATA VPD page.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_inq_89(struct ata_scsi_args *args, u8 *rbuf)
  {
  	struct ata_taskfile tf;
  
  	memset(&tf, 0, sizeof(tf));
  
  	rbuf[1] = 0x89;			/* our page code */
  	rbuf[2] = (0x238 >> 8);		/* page size fixed at 238h */
  	rbuf[3] = (0x238 & 0xff);
  
  	memcpy(&rbuf[8], "linux   ", 8);
  	memcpy(&rbuf[16], "libata          ", 16);
  	memcpy(&rbuf[32], DRV_VERSION, 4);
  
  	/* we don't store the ATA device signature, so we fake it */
  
  	tf.command = ATA_DRDY;		/* really, this is Status reg */
  	tf.lbal = 0x1;
  	tf.nsect = 0x1;
  
  	ata_tf_to_fis(&tf, 0, 1, &rbuf[36]);	/* TODO: PMP? */
  	rbuf[36] = 0x34;		/* force D2H Reg FIS (34h) */
  
  	rbuf[56] = ATA_CMD_ID_ATA;
  
  	memcpy(&rbuf[60], &args->id[0], 512);
  	return 0;
  }
  
  static unsigned int ata_scsiop_inq_b0(struct ata_scsi_args *args, u8 *rbuf)
  {
  	u16 min_io_sectors;
  
  	rbuf[1] = 0xb0;
  	rbuf[3] = 0x3c;		/* required VPD size with unmap support */
  
  	/*
  	 * Optimal transfer length granularity.
  	 *
  	 * This is always one physical block, but for disks with a smaller
  	 * logical than physical sector size we need to figure out what the
  	 * latter is.
  	 */
  	min_io_sectors = 1 << ata_id_log2_per_physical_sector(args->id);
  	put_unaligned_be16(min_io_sectors, &rbuf[6]);
  
  	/*
  	 * Optimal unmap granularity.
  	 *
  	 * The ATA spec doesn't even know about a granularity or alignment
  	 * for the TRIM command.  We can leave away most of the unmap related
  	 * VPD page entries, but we have specifify a granularity to signal
  	 * that we support some form of unmap - in thise case via WRITE SAME
  	 * with the unmap bit set.
  	 */
  	if (ata_id_has_trim(args->id)) {
  		put_unaligned_be64(65535 * ATA_MAX_TRIM_RNUM, &rbuf[36]);
  		put_unaligned_be32(1, &rbuf[28]);
  	}
  
  	return 0;
  }
  
  static unsigned int ata_scsiop_inq_b1(struct ata_scsi_args *args, u8 *rbuf)
  {
  	int form_factor = ata_id_form_factor(args->id);
  	int media_rotation_rate = ata_id_rotation_rate(args->id);
  	u8 zoned = ata_id_zoned_cap(args->id);
  
  	rbuf[1] = 0xb1;
  	rbuf[3] = 0x3c;
  	rbuf[4] = media_rotation_rate >> 8;
  	rbuf[5] = media_rotation_rate;
  	rbuf[7] = form_factor;
  	if (zoned)
  		rbuf[8] = (zoned << 4);
  
  	return 0;
  }
  
  static unsigned int ata_scsiop_inq_b2(struct ata_scsi_args *args, u8 *rbuf)
  {
  	/* SCSI Thin Provisioning VPD page: SBC-3 rev 22 or later */
  	rbuf[1] = 0xb2;
  	rbuf[3] = 0x4;
  	rbuf[5] = 1 << 6;	/* TPWS */
  
  	return 0;
  }
  
  static unsigned int ata_scsiop_inq_b6(struct ata_scsi_args *args, u8 *rbuf)
  {
  	/*
  	 * zbc-r05 SCSI Zoned Block device characteristics VPD page
  	 */
  	rbuf[1] = 0xb6;
  	rbuf[3] = 0x3C;
  
  	/*
  	 * URSWRZ bit is only meaningful for host-managed ZAC drives
  	 */
  	if (args->dev->zac_zoned_cap & 1)
  		rbuf[4] |= 1;
  	put_unaligned_be32(args->dev->zac_zones_optimal_open, &rbuf[8]);
  	put_unaligned_be32(args->dev->zac_zones_optimal_nonseq, &rbuf[12]);
  	put_unaligned_be32(args->dev->zac_zones_max_open, &rbuf[16]);
  
  	return 0;
  }
  
  /**
   *	modecpy - Prepare response for MODE SENSE
   *	@dest: output buffer
   *	@src: data being copied
   *	@n: length of mode page
   *	@changeable: whether changeable parameters are requested
   *
   *	Generate a generic MODE SENSE page for either current or changeable
   *	parameters.
   *
   *	LOCKING:
   *	None.
   */
  static void modecpy(u8 *dest, const u8 *src, int n, bool changeable)
  {
  	if (changeable) {
  		memcpy(dest, src, 2);
  		memset(dest + 2, 0, n - 2);
  	} else {
  		memcpy(dest, src, n);
  	}
  }
  
  /**
   *	ata_msense_caching - Simulate MODE SENSE caching info page
   *	@id: device IDENTIFY data
   *	@buf: output buffer
   *	@changeable: whether changeable parameters are requested
   *
   *	Generate a caching info page, which conditionally indicates
   *	write caching to the SCSI layer, depending on device
   *	capabilities.
   *
   *	LOCKING:
   *	None.
   */
  static unsigned int ata_msense_caching(u16 *id, u8 *buf, bool changeable)
  {
  	modecpy(buf, def_cache_mpage, sizeof(def_cache_mpage), changeable);
  	if (changeable) {
  		buf[2] |= (1 << 2);	/* ata_mselect_caching() */
  	} else {
  		buf[2] |= (ata_id_wcache_enabled(id) << 2);	/* write cache enable */
  		buf[12] |= (!ata_id_rahead_enabled(id) << 5);	/* disable read ahead */
  	}
  	return sizeof(def_cache_mpage);
  }
  
  /**
   *	ata_msense_control - Simulate MODE SENSE control mode page
   *	@dev: ATA device of interest
   *	@buf: output buffer
   *	@changeable: whether changeable parameters are requested
   *
   *	Generate a generic MODE SENSE control mode page.
   *
   *	LOCKING:
   *	None.
   */
  static unsigned int ata_msense_control(struct ata_device *dev, u8 *buf,
  					bool changeable)
  {
  	modecpy(buf, def_control_mpage, sizeof(def_control_mpage), changeable);
  	if (changeable) {
  		buf[2] |= (1 << 2);	/* ata_mselect_control() */
  	} else {
  		bool d_sense = (dev->flags & ATA_DFLAG_D_SENSE);
  
  		buf[2] |= (d_sense << 2);	/* descriptor format sense data */
  	}
  	return sizeof(def_control_mpage);
  }
  
  /**
   *	ata_msense_rw_recovery - Simulate MODE SENSE r/w error recovery page
   *	@buf: output buffer
   *	@changeable: whether changeable parameters are requested
   *
   *	Generate a generic MODE SENSE r/w error recovery page.
   *
   *	LOCKING:
   *	None.
   */
  static unsigned int ata_msense_rw_recovery(u8 *buf, bool changeable)
  {
  	modecpy(buf, def_rw_recovery_mpage, sizeof(def_rw_recovery_mpage),
  		changeable);
  	return sizeof(def_rw_recovery_mpage);
  }
  
  /*
   * We can turn this into a real blacklist if it's needed, for now just
   * blacklist any Maxtor BANC1G10 revision firmware
   */
  static int ata_dev_supports_fua(u16 *id)
  {
  	unsigned char model[ATA_ID_PROD_LEN + 1], fw[ATA_ID_FW_REV_LEN + 1];
  
  	if (!libata_fua)
  		return 0;
  	if (!ata_id_has_fua(id))
  		return 0;
  
  	ata_id_c_string(id, model, ATA_ID_PROD, sizeof(model));
  	ata_id_c_string(id, fw, ATA_ID_FW_REV, sizeof(fw));
  
  	if (strcmp(model, "Maxtor"))
  		return 1;
  	if (strcmp(fw, "BANC1G10"))
  		return 1;
  
  	return 0; /* blacklisted */
  }
  
  /**
   *	ata_scsiop_mode_sense - Simulate MODE SENSE 6, 10 commands
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Simulate MODE SENSE commands. Assume this is invoked for direct
   *	access devices (e.g. disks) only. There should be no block
   *	descriptor for other device types.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
  {
  	struct ata_device *dev = args->dev;
  	u8 *scsicmd = args->cmd->cmnd, *p = rbuf;
  	const u8 sat_blk_desc[] = {
  		0, 0, 0, 0,	/* number of blocks: sat unspecified */
  		0,
  		0, 0x2, 0x0	/* block length: 512 bytes */
  	};
  	u8 pg, spg;
  	unsigned int ebd, page_control, six_byte;
  	u8 dpofua, bp = 0xff;
  	u16 fp;
  
  	VPRINTK("ENTER\n");
  
  	six_byte = (scsicmd[0] == MODE_SENSE);
  	ebd = !(scsicmd[1] & 0x8);      /* dbd bit inverted == edb */
  	/*
  	 * LLBA bit in msense(10) ignored (compliant)
  	 */
  
  	page_control = scsicmd[2] >> 6;
  	switch (page_control) {
  	case 0: /* current */
  	case 1: /* changeable */
  	case 2: /* defaults */
  		break;  /* supported */
  	case 3: /* saved */
  		goto saving_not_supp;
  	default:
  		fp = 2;
  		bp = 6;
  		goto invalid_fld;
  	}
  
  	if (six_byte)
  		p += 4 + (ebd ? 8 : 0);
  	else
  		p += 8 + (ebd ? 8 : 0);
  
  	pg = scsicmd[2] & 0x3f;
  	spg = scsicmd[3];
  	/*
  	 * No mode subpages supported (yet) but asking for _all_
  	 * subpages may be valid
  	 */
  	if (spg && (spg != ALL_SUB_MPAGES)) {
  		fp = 3;
  		goto invalid_fld;
  	}
  
  	switch(pg) {
  	case RW_RECOVERY_MPAGE:
  		p += ata_msense_rw_recovery(p, page_control == 1);
  		break;
  
  	case CACHE_MPAGE:
  		p += ata_msense_caching(args->id, p, page_control == 1);
  		break;
  
  	case CONTROL_MPAGE:
  		p += ata_msense_control(args->dev, p, page_control == 1);
  		break;
  
  	case ALL_MPAGES:
  		p += ata_msense_rw_recovery(p, page_control == 1);
  		p += ata_msense_caching(args->id, p, page_control == 1);
  		p += ata_msense_control(args->dev, p, page_control == 1);
  		break;
  
  	default:		/* invalid page code */
  		fp = 2;
  		goto invalid_fld;
  	}
  
  	dpofua = 0;
  	if (ata_dev_supports_fua(args->id) && (dev->flags & ATA_DFLAG_LBA48) &&
  	    (!(dev->flags & ATA_DFLAG_PIO) || dev->multi_count))
  		dpofua = 1 << 4;
  
  	if (six_byte) {
  		rbuf[0] = p - rbuf - 1;
  		rbuf[2] |= dpofua;
  		if (ebd) {
  			rbuf[3] = sizeof(sat_blk_desc);
  			memcpy(rbuf + 4, sat_blk_desc, sizeof(sat_blk_desc));
  		}
  	} else {
  		unsigned int output_len = p - rbuf - 2;
  
  		rbuf[0] = output_len >> 8;
  		rbuf[1] = output_len;
  		rbuf[3] |= dpofua;
  		if (ebd) {
  			rbuf[7] = sizeof(sat_blk_desc);
  			memcpy(rbuf + 8, sat_blk_desc, sizeof(sat_blk_desc));
  		}
  	}
  	return 0;
  
  invalid_fld:
  	ata_scsi_set_invalid_field(dev, args->cmd, fp, bp);
  	return 1;
  
  saving_not_supp:
  	ata_scsi_set_sense(dev, args->cmd, ILLEGAL_REQUEST, 0x39, 0x0);
  	 /* "Saving parameters not supported" */
  	return 1;
  }
  
  /**
   *	ata_scsiop_read_cap - Simulate READ CAPACITY[ 16] commands
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Simulate READ CAPACITY commands.
   *
   *	LOCKING:
   *	None.
   */
  static unsigned int ata_scsiop_read_cap(struct ata_scsi_args *args, u8 *rbuf)
  {
  	struct ata_device *dev = args->dev;
  	u64 last_lba = dev->n_sectors - 1; /* LBA of the last block */
  	u32 sector_size; /* physical sector size in bytes */
  	u8 log2_per_phys;
  	u16 lowest_aligned;
  
  	sector_size = ata_id_logical_sector_size(dev->id);
  	log2_per_phys = ata_id_log2_per_physical_sector(dev->id);
  	lowest_aligned = ata_id_logical_sector_offset(dev->id, log2_per_phys);
  
  	VPRINTK("ENTER\n");
  
  	if (args->cmd->cmnd[0] == READ_CAPACITY) {
  		if (last_lba >= 0xffffffffULL)
  			last_lba = 0xffffffff;
  
  		/* sector count, 32-bit */
  		rbuf[0] = last_lba >> (8 * 3);
  		rbuf[1] = last_lba >> (8 * 2);
  		rbuf[2] = last_lba >> (8 * 1);
  		rbuf[3] = last_lba;
  
  		/* sector size */
  		rbuf[4] = sector_size >> (8 * 3);
  		rbuf[5] = sector_size >> (8 * 2);
  		rbuf[6] = sector_size >> (8 * 1);
  		rbuf[7] = sector_size;
  	} else {
  		/* sector count, 64-bit */
  		rbuf[0] = last_lba >> (8 * 7);
  		rbuf[1] = last_lba >> (8 * 6);
  		rbuf[2] = last_lba >> (8 * 5);
  		rbuf[3] = last_lba >> (8 * 4);
  		rbuf[4] = last_lba >> (8 * 3);
  		rbuf[5] = last_lba >> (8 * 2);
  		rbuf[6] = last_lba >> (8 * 1);
  		rbuf[7] = last_lba;
  
  		/* sector size */
  		rbuf[ 8] = sector_size >> (8 * 3);
  		rbuf[ 9] = sector_size >> (8 * 2);
  		rbuf[10] = sector_size >> (8 * 1);
  		rbuf[11] = sector_size;
  
  		rbuf[12] = 0;
  		rbuf[13] = log2_per_phys;
  		rbuf[14] = (lowest_aligned >> 8) & 0x3f;
  		rbuf[15] = lowest_aligned;
  
  		if (ata_id_has_trim(args->id) &&
  		    !(dev->horkage & ATA_HORKAGE_NOTRIM)) {
  			rbuf[14] |= 0x80; /* LBPME */
  
  			if (ata_id_has_zero_after_trim(args->id) &&
  			    dev->horkage & ATA_HORKAGE_ZERO_AFTER_TRIM) {
  				ata_dev_info(dev, "Enabling discard_zeroes_data\n");
  				rbuf[14] |= 0x40; /* LBPRZ */
  			}
  		}
  		if (ata_id_zoned_cap(args->id) ||
  		    args->dev->class == ATA_DEV_ZAC)
  			rbuf[12] = (1 << 4); /* RC_BASIS */
  	}
  	return 0;
  }
  
  /**
   *	ata_scsiop_report_luns - Simulate REPORT LUNS command
   *	@args: device IDENTIFY data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Simulate REPORT LUNS command.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_report_luns(struct ata_scsi_args *args, u8 *rbuf)
  {
  	VPRINTK("ENTER\n");
  	rbuf[3] = 8;	/* just one lun, LUN 0, size 8 bytes */
  
  	return 0;
  }
  
  static void atapi_sense_complete(struct ata_queued_cmd *qc)
  {
  	if (qc->err_mask && ((qc->err_mask & AC_ERR_DEV) == 0)) {
  		/* FIXME: not quite right; we don't want the
  		 * translation of taskfile registers into
  		 * a sense descriptors, since that's only
  		 * correct for ATA, not ATAPI
  		 */
  		ata_gen_passthru_sense(qc);
  	}
  
  	ata_qc_done(qc);
  }
  
  /* is it pointless to prefer PIO for "safety reasons"? */
  static inline int ata_pio_use_silly(struct ata_port *ap)
  {
  	return (ap->flags & ATA_FLAG_PIO_DMA);
  }
  
  static void atapi_request_sense(struct ata_queued_cmd *qc)
  {
  	struct ata_port *ap = qc->ap;
  	struct scsi_cmnd *cmd = qc->scsicmd;
  
  	DPRINTK("ATAPI request sense\n");
  
  	memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
  
  #ifdef CONFIG_ATA_SFF
  	if (ap->ops->sff_tf_read)
  		ap->ops->sff_tf_read(ap, &qc->tf);
  #endif
  
  	/* fill these in, for the case where they are -not- overwritten */
  	cmd->sense_buffer[0] = 0x70;
  	cmd->sense_buffer[2] = qc->tf.feature >> 4;
  
  	ata_qc_reinit(qc);
  
  	/* setup sg table and init transfer direction */
  	sg_init_one(&qc->sgent, cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
  	ata_sg_init(qc, &qc->sgent, 1);
  	qc->dma_dir = DMA_FROM_DEVICE;
  
  	memset(&qc->cdb, 0, qc->dev->cdb_len);
  	qc->cdb[0] = REQUEST_SENSE;
  	qc->cdb[4] = SCSI_SENSE_BUFFERSIZE;
  
  	qc->tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
  	qc->tf.command = ATA_CMD_PACKET;
  
  	if (ata_pio_use_silly(ap)) {
  		qc->tf.protocol = ATAPI_PROT_DMA;
  		qc->tf.feature |= ATAPI_PKT_DMA;
  	} else {
  		qc->tf.protocol = ATAPI_PROT_PIO;
  		qc->tf.lbam = SCSI_SENSE_BUFFERSIZE;
  		qc->tf.lbah = 0;
  	}
  	qc->nbytes = SCSI_SENSE_BUFFERSIZE;
  
  	qc->complete_fn = atapi_sense_complete;
  
  	ata_qc_issue(qc);
  
  	DPRINTK("EXIT\n");
  }
  
  /*
   * ATAPI devices typically report zero for their SCSI version, and sometimes
   * deviate from the spec WRT response data format.  If SCSI version is
   * reported as zero like normal, then we make the following fixups:
   *   1) Fake MMC-5 version, to indicate to the Linux scsi midlayer this is a
   *	modern device.
   *   2) Ensure response data format / ATAPI information are always correct.
   */
  static void atapi_fixup_inquiry(struct scsi_cmnd *cmd)
  {
  	u8 buf[4];
  
  	sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, 4);
  	if (buf[2] == 0) {
  		buf[2] = 0x5;
  		buf[3] = 0x32;
  	}
  	sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, 4);
  }
  
  static void atapi_qc_complete(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *cmd = qc->scsicmd;
  	unsigned int err_mask = qc->err_mask;
  
  	VPRINTK("ENTER, err_mask 0x%X\n", err_mask);
  
  	/* handle completion from new EH */
  	if (unlikely(qc->ap->ops->error_handler &&
  		     (err_mask || qc->flags & ATA_QCFLAG_SENSE_VALID))) {
  
  		if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)) {
  			/* FIXME: not quite right; we don't want the
  			 * translation of taskfile registers into a
  			 * sense descriptors, since that's only
  			 * correct for ATA, not ATAPI
  			 */
  			ata_gen_passthru_sense(qc);
  		}
  
  		/* SCSI EH automatically locks door if sdev->locked is
  		 * set.  Sometimes door lock request continues to
  		 * fail, for example, when no media is present.  This
  		 * creates a loop - SCSI EH issues door lock which
  		 * fails and gets invoked again to acquire sense data
  		 * for the failed command.
  		 *
  		 * If door lock fails, always clear sdev->locked to
  		 * avoid this infinite loop.
  		 *
  		 * This may happen before SCSI scan is complete.  Make
  		 * sure qc->dev->sdev isn't NULL before dereferencing.
  		 */
  		if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL && qc->dev->sdev)
  			qc->dev->sdev->locked = 0;
  
  		qc->scsicmd->result = SAM_STAT_CHECK_CONDITION;
  		ata_qc_done(qc);
  		return;
  	}
  
  	/* successful completion or old EH failure path */
  	if (unlikely(err_mask & AC_ERR_DEV)) {
  		cmd->result = SAM_STAT_CHECK_CONDITION;
  		atapi_request_sense(qc);
  		return;
  	} else if (unlikely(err_mask)) {
  		/* FIXME: not quite right; we don't want the
  		 * translation of taskfile registers into
  		 * a sense descriptors, since that's only
  		 * correct for ATA, not ATAPI
  		 */
  		ata_gen_passthru_sense(qc);
  	} else {
  		if (cmd->cmnd[0] == INQUIRY && (cmd->cmnd[1] & 0x03) == 0)
  			atapi_fixup_inquiry(cmd);
  		cmd->result = SAM_STAT_GOOD;
  	}
  
  	ata_qc_done(qc);
  }
  /**
   *	atapi_xlat - Initialize PACKET taskfile
   *	@qc: command structure to be initialized
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   *
   *	RETURNS:
   *	Zero on success, non-zero on failure.
   */
  static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	struct ata_device *dev = qc->dev;
  	int nodata = (scmd->sc_data_direction == DMA_NONE);
  	int using_pio = !nodata && (dev->flags & ATA_DFLAG_PIO);
  	unsigned int nbytes;
  
  	memset(qc->cdb, 0, dev->cdb_len);
  	memcpy(qc->cdb, scmd->cmnd, scmd->cmd_len);
  
  	qc->complete_fn = atapi_qc_complete;
  
  	qc->tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
  	if (scmd->sc_data_direction == DMA_TO_DEVICE) {
  		qc->tf.flags |= ATA_TFLAG_WRITE;
  		DPRINTK("direction: write\n");
  	}
  
  	qc->tf.command = ATA_CMD_PACKET;
  	ata_qc_set_pc_nbytes(qc);
  
  	/* check whether ATAPI DMA is safe */
  	if (!nodata && !using_pio && atapi_check_dma(qc))
  		using_pio = 1;
  
  	/* Some controller variants snoop this value for Packet
  	 * transfers to do state machine and FIFO management.  Thus we
  	 * want to set it properly, and for DMA where it is
  	 * effectively meaningless.
  	 */
  	nbytes = min(ata_qc_raw_nbytes(qc), (unsigned int)63 * 1024);
  
  	/* Most ATAPI devices which honor transfer chunk size don't
  	 * behave according to the spec when odd chunk size which
  	 * matches the transfer length is specified.  If the number of
  	 * bytes to transfer is 2n+1.  According to the spec, what
  	 * should happen is to indicate that 2n+1 is going to be
  	 * transferred and transfer 2n+2 bytes where the last byte is
  	 * padding.
  	 *
  	 * In practice, this doesn't happen.  ATAPI devices first
  	 * indicate and transfer 2n bytes and then indicate and
  	 * transfer 2 bytes where the last byte is padding.
  	 *
  	 * This inconsistency confuses several controllers which
  	 * perform PIO using DMA such as Intel AHCIs and sil3124/32.
  	 * These controllers use actual number of transferred bytes to
  	 * update DMA poitner and transfer of 4n+2 bytes make those
  	 * controller push DMA pointer by 4n+4 bytes because SATA data
  	 * FISes are aligned to 4 bytes.  This causes data corruption
  	 * and buffer overrun.
  	 *
  	 * Always setting nbytes to even number solves this problem
  	 * because then ATAPI devices don't have to split data at 2n
  	 * boundaries.
  	 */
  	if (nbytes & 0x1)
  		nbytes++;
  
  	qc->tf.lbam = (nbytes & 0xFF);
  	qc->tf.lbah = (nbytes >> 8);
  
  	if (nodata)
  		qc->tf.protocol = ATAPI_PROT_NODATA;
  	else if (using_pio)
  		qc->tf.protocol = ATAPI_PROT_PIO;
  	else {
  		/* DMA data xfer */
  		qc->tf.protocol = ATAPI_PROT_DMA;
  		qc->tf.feature |= ATAPI_PKT_DMA;
  
  		if ((dev->flags & ATA_DFLAG_DMADIR) &&
  		    (scmd->sc_data_direction != DMA_TO_DEVICE))
  			/* some SATA bridges need us to indicate data xfer direction */
  			qc->tf.feature |= ATAPI_DMADIR;
  	}
  
  
  	/* FIXME: We need to translate 0x05 READ_BLOCK_LIMITS to a MODE_SENSE
  	   as ATAPI tape drives don't get this right otherwise */
  	return 0;
  }
  
  static struct ata_device *ata_find_dev(struct ata_port *ap, int devno)
  {
  	if (!sata_pmp_attached(ap)) {
  		if (likely(devno >= 0 &&
  			   devno < ata_link_max_devices(&ap->link)))
  			return &ap->link.device[devno];
  	} else {
  		if (likely(devno >= 0 &&
  			   devno < ap->nr_pmp_links))
  			return &ap->pmp_link[devno].device[0];
  	}
  
  	return NULL;
  }
  
  static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
  					      const struct scsi_device *scsidev)
  {
  	int devno;
  
  	/* skip commands not addressed to targets we simulate */
  	if (!sata_pmp_attached(ap)) {
  		if (unlikely(scsidev->channel || scsidev->lun))
  			return NULL;
  		devno = scsidev->id;
  	} else {
  		if (unlikely(scsidev->id || scsidev->lun))
  			return NULL;
  		devno = scsidev->channel;
  	}
  
  	return ata_find_dev(ap, devno);
  }
  
  /**
   *	ata_scsi_find_dev - lookup ata_device from scsi_cmnd
   *	@ap: ATA port to which the device is attached
   *	@scsidev: SCSI device from which we derive the ATA device
   *
   *	Given various information provided in struct scsi_cmnd,
   *	map that onto an ATA bus, and using that mapping
   *	determine which ata_device is associated with the
   *	SCSI command to be sent.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   *
   *	RETURNS:
   *	Associated ATA device, or %NULL if not found.
   */
  static struct ata_device *
  ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev)
  {
  	struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
  
  	if (unlikely(!dev || !ata_dev_enabled(dev)))
  		return NULL;
  
  	return dev;
  }
  
  /*
   *	ata_scsi_map_proto - Map pass-thru protocol value to taskfile value.
   *	@byte1: Byte 1 from pass-thru CDB.
   *
   *	RETURNS:
   *	ATA_PROT_UNKNOWN if mapping failed/unimplemented, protocol otherwise.
   */
  static u8
  ata_scsi_map_proto(u8 byte1)
  {
  	switch((byte1 & 0x1e) >> 1) {
  	case 3:		/* Non-data */
  		return ATA_PROT_NODATA;
  
  	case 6:		/* DMA */
  	case 10:	/* UDMA Data-in */
  	case 11:	/* UDMA Data-Out */
  		return ATA_PROT_DMA;
  
  	case 4:		/* PIO Data-in */
  	case 5:		/* PIO Data-out */
  		return ATA_PROT_PIO;
  
  	case 12:	/* FPDMA */
  		return ATA_PROT_NCQ;
  
  	case 0:		/* Hard Reset */
  	case 1:		/* SRST */
  	case 8:		/* Device Diagnostic */
  	case 9:		/* Device Reset */
  	case 7:		/* DMA Queued */
  	case 15:	/* Return Response Info */
  	default:	/* Reserved */
  		break;
  	}
  
  	return ATA_PROT_UNKNOWN;
  }
  
  /**
   *	ata_scsi_pass_thru - convert ATA pass-thru CDB to taskfile
   *	@qc: command structure to be initialized
   *
   *	Handles either 12, 16, or 32-byte versions of the CDB.
   *
   *	RETURNS:
   *	Zero on success, non-zero on failure.
   */
  static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
  {
  	struct ata_taskfile *tf = &(qc->tf);
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	struct ata_device *dev = qc->dev;
  	const u8 *cdb = scmd->cmnd;
  	u16 fp;
  	u16 cdb_offset = 0;
  
  	/* 7Fh variable length cmd means a ata pass-thru(32) */
  	if (cdb[0] == VARIABLE_LENGTH_CMD)
  		cdb_offset = 9;
  
  	tf->protocol = ata_scsi_map_proto(cdb[1 + cdb_offset]);
  	if (tf->protocol == ATA_PROT_UNKNOWN) {
  		fp = 1;
  		goto invalid_fld;
  	}
  
  	if (ata_is_ncq(tf->protocol) && (cdb[2 + cdb_offset] & 0x3) == 0)
  		tf->protocol = ATA_PROT_NCQ_NODATA;
  
  	/* enable LBA */
  	tf->flags |= ATA_TFLAG_LBA;
  
  	/*
  	 * 12 and 16 byte CDBs use different offsets to
  	 * provide the various register values.
  	 */
  	if (cdb[0] == ATA_16) {
  		/*
  		 * 16-byte CDB - may contain extended commands.
  		 *
  		 * If that is the case, copy the upper byte register values.
  		 */
  		if (cdb[1] & 0x01) {
  			tf->hob_feature = cdb[3];
  			tf->hob_nsect = cdb[5];
  			tf->hob_lbal = cdb[7];
  			tf->hob_lbam = cdb[9];
  			tf->hob_lbah = cdb[11];
  			tf->flags |= ATA_TFLAG_LBA48;
  		} else
  			tf->flags &= ~ATA_TFLAG_LBA48;
  
  		/*
  		 * Always copy low byte, device and command registers.
  		 */
  		tf->feature = cdb[4];
  		tf->nsect = cdb[6];
  		tf->lbal = cdb[8];
  		tf->lbam = cdb[10];
  		tf->lbah = cdb[12];
  		tf->device = cdb[13];
  		tf->command = cdb[14];
  	} else if (cdb[0] == ATA_12) {
  		/*
  		 * 12-byte CDB - incapable of extended commands.
  		 */
  		tf->flags &= ~ATA_TFLAG_LBA48;
  
  		tf->feature = cdb[3];
  		tf->nsect = cdb[4];
  		tf->lbal = cdb[5];
  		tf->lbam = cdb[6];
  		tf->lbah = cdb[7];
  		tf->device = cdb[8];
  		tf->command = cdb[9];
  	} else {
  		/*
  		 * 32-byte CDB - may contain extended command fields.
  		 *
  		 * If that is the case, copy the upper byte register values.
  		 */
  		if (cdb[10] & 0x01) {
  			tf->hob_feature = cdb[20];
  			tf->hob_nsect = cdb[22];
  			tf->hob_lbal = cdb[16];
  			tf->hob_lbam = cdb[15];
  			tf->hob_lbah = cdb[14];
  			tf->flags |= ATA_TFLAG_LBA48;
  		} else
  			tf->flags &= ~ATA_TFLAG_LBA48;
  
  		tf->feature = cdb[21];
  		tf->nsect = cdb[23];
  		tf->lbal = cdb[19];
  		tf->lbam = cdb[18];
  		tf->lbah = cdb[17];
  		tf->device = cdb[24];
  		tf->command = cdb[25];
  		tf->auxiliary = get_unaligned_be32(&cdb[28]);
  	}
  
  	/* For NCQ commands copy the tag value */
  	if (ata_is_ncq(tf->protocol))
  		tf->nsect = qc->tag << 3;
  
  	/* enforce correct master/slave bit */
  	tf->device = dev->devno ?
  		tf->device | ATA_DEV1 : tf->device & ~ATA_DEV1;
  
  	switch (tf->command) {
  	/* READ/WRITE LONG use a non-standard sect_size */
  	case ATA_CMD_READ_LONG:
  	case ATA_CMD_READ_LONG_ONCE:
  	case ATA_CMD_WRITE_LONG:
  	case ATA_CMD_WRITE_LONG_ONCE:
  		if (tf->protocol != ATA_PROT_PIO || tf->nsect != 1) {
  			fp = 1;
  			goto invalid_fld;
  		}
  		qc->sect_size = scsi_bufflen(scmd);
  		break;
  
  	/* commands using reported Logical Block size (e.g. 512 or 4K) */
  	case ATA_CMD_CFA_WRITE_NE:
  	case ATA_CMD_CFA_TRANS_SECT:
  	case ATA_CMD_CFA_WRITE_MULT_NE:
  	/* XXX: case ATA_CMD_CFA_WRITE_SECTORS_WITHOUT_ERASE: */
  	case ATA_CMD_READ:
  	case ATA_CMD_READ_EXT:
  	case ATA_CMD_READ_QUEUED:
  	/* XXX: case ATA_CMD_READ_QUEUED_EXT: */
  	case ATA_CMD_FPDMA_READ:
  	case ATA_CMD_READ_MULTI:
  	case ATA_CMD_READ_MULTI_EXT:
  	case ATA_CMD_PIO_READ:
  	case ATA_CMD_PIO_READ_EXT:
  	case ATA_CMD_READ_STREAM_DMA_EXT:
  	case ATA_CMD_READ_STREAM_EXT:
  	case ATA_CMD_VERIFY:
  	case ATA_CMD_VERIFY_EXT:
  	case ATA_CMD_WRITE:
  	case ATA_CMD_WRITE_EXT:
  	case ATA_CMD_WRITE_FUA_EXT:
  	case ATA_CMD_WRITE_QUEUED:
  	case ATA_CMD_WRITE_QUEUED_FUA_EXT:
  	case ATA_CMD_FPDMA_WRITE:
  	case ATA_CMD_WRITE_MULTI:
  	case ATA_CMD_WRITE_MULTI_EXT:
  	case ATA_CMD_WRITE_MULTI_FUA_EXT:
  	case ATA_CMD_PIO_WRITE:
  	case ATA_CMD_PIO_WRITE_EXT:
  	case ATA_CMD_WRITE_STREAM_DMA_EXT:
  	case ATA_CMD_WRITE_STREAM_EXT:
  		qc->sect_size = scmd->device->sector_size;
  		break;
  
  	/* Everything else uses 512 byte "sectors" */
  	default:
  		qc->sect_size = ATA_SECT_SIZE;
  	}
  
  	/*
  	 * Set flags so that all registers will be written, pass on
  	 * write indication (used for PIO/DMA setup), result TF is
  	 * copied back and we don't whine too much about its failure.
  	 */
  	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
  	if (scmd->sc_data_direction == DMA_TO_DEVICE)
  		tf->flags |= ATA_TFLAG_WRITE;
  
  	qc->flags |= ATA_QCFLAG_RESULT_TF | ATA_QCFLAG_QUIET;
  
  	/*
  	 * Set transfer length.
  	 *
  	 * TODO: find out if we need to do more here to
  	 *       cover scatter/gather case.
  	 */
  	ata_qc_set_pc_nbytes(qc);
  
  	/* We may not issue DMA commands if no DMA mode is set */
  	if (tf->protocol == ATA_PROT_DMA && dev->dma_mode == 0) {
  		fp = 1;
  		goto invalid_fld;
  	}
  
  	/* sanity check for pio multi commands */
  	if ((cdb[1] & 0xe0) && !is_multi_taskfile(tf)) {
  		fp = 1;
  		goto invalid_fld;
  	}
  
  	if (is_multi_taskfile(tf)) {
  		unsigned int multi_count = 1 << (cdb[1] >> 5);
  
  		/* compare the passed through multi_count
  		 * with the cached multi_count of libata
  		 */
  		if (multi_count != dev->multi_count)
  			ata_dev_warn(dev, "invalid multi_count %u ignored\n",
  				     multi_count);
  	}
  
  	/*
  	 * Filter SET_FEATURES - XFER MODE command -- otherwise,
  	 * SET_FEATURES - XFER MODE must be preceded/succeeded
  	 * by an update to hardware-specific registers for each
  	 * controller (i.e. the reason for ->set_piomode(),
  	 * ->set_dmamode(), and ->post_set_mode() hooks).
  	 */
  	if (tf->command == ATA_CMD_SET_FEATURES &&
  	    tf->feature == SETFEATURES_XFER) {
  		fp = (cdb[0] == ATA_16) ? 4 : 3;
  		goto invalid_fld;
  	}
  
  	/*
  	 * Filter TPM commands by default. These provide an
  	 * essentially uncontrolled encrypted "back door" between
  	 * applications and the disk. Set libata.allow_tpm=1 if you
  	 * have a real reason for wanting to use them. This ensures
  	 * that installed software cannot easily mess stuff up without
  	 * user intent. DVR type users will probably ship with this enabled
  	 * for movie content management.
  	 *
  	 * Note that for ATA8 we can issue a DCS change and DCS freeze lock
  	 * for this and should do in future but that it is not sufficient as
  	 * DCS is an optional feature set. Thus we also do the software filter
  	 * so that we comply with the TC consortium stated goal that the user
  	 * can turn off TC features of their system.
  	 */
  	if (tf->command >= 0x5C && tf->command <= 0x5F && !libata_allow_tpm) {
  		fp = (cdb[0] == ATA_16) ? 14 : 9;
  		goto invalid_fld;
  	}
  
  	return 0;
  
   invalid_fld:
  	ata_scsi_set_invalid_field(dev, scmd, fp, 0xff);
  	return 1;
  }
  
  /**
   * ata_format_dsm_trim_descr() - SATL Write Same to DSM Trim
   * @cmd: SCSI command being translated
   * @trmax: Maximum number of entries that will fit in sector_size bytes.
   * @sector: Starting sector
   * @count: Total Range of request in logical sectors
   *
   * Rewrite the WRITE SAME descriptor to be a DSM TRIM little-endian formatted
   * descriptor.
   *
   * Upto 64 entries of the format:
   *   63:48 Range Length
   *   47:0  LBA
   *
   *  Range Length of 0 is ignored.
   *  LBA's should be sorted order and not overlap.
   *
   * NOTE: this is the same format as ADD LBA(S) TO NV CACHE PINNED SET
   *
   * Return: Number of bytes copied into sglist.
   */
  static size_t ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 trmax,
  					u64 sector, u32 count)
  {
  	struct scsi_device *sdp = cmd->device;
  	size_t len = sdp->sector_size;
  	size_t r;
  	__le64 *buf;
  	u32 i = 0;
  	unsigned long flags;
  
  	WARN_ON(len > ATA_SCSI_RBUF_SIZE);
  
  	if (len > ATA_SCSI_RBUF_SIZE)
  		len = ATA_SCSI_RBUF_SIZE;
  
  	spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);
  	buf = ((void *)ata_scsi_rbuf);
  	memset(buf, 0, len);
  	while (i < trmax) {
  		u64 entry = sector |
  			((u64)(count > 0xffff ? 0xffff : count) << 48);
  		buf[i++] = __cpu_to_le64(entry);
  		if (count <= 0xffff)
  			break;
  		count -= 0xffff;
  		sector += 0xffff;
  	}
  	r = sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), buf, len);
  	spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);
  
  	return r;
  }
  
  /**
   * ata_scsi_write_same_xlat() - SATL Write Same to ATA SCT Write Same
   * @qc: Command to be translated
   *
   * Translate a SCSI WRITE SAME command to be either a DSM TRIM command or
   * an SCT Write Same command.
   * Based on WRITE SAME has the UNMAP flag:
   *
   *   - When set translate to DSM TRIM
   *   - When clear translate to SCT Write Same
   */
  static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
  {
  	struct ata_taskfile *tf = &qc->tf;
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	struct scsi_device *sdp = scmd->device;
  	size_t len = sdp->sector_size;
  	struct ata_device *dev = qc->dev;
  	const u8 *cdb = scmd->cmnd;
  	u64 block;
  	u32 n_block;
  	const u32 trmax = len >> 3;
  	u32 size;
  	u16 fp;
  	u8 bp = 0xff;
  	u8 unmap = cdb[1] & 0x8;
  
  	/* we may not issue DMA commands if no DMA mode is set */
  	if (unlikely(!dev->dma_mode))
  		goto invalid_opcode;
  
  	/*
  	 * We only allow sending this command through the block layer,
  	 * as it modifies the DATA OUT buffer, which would corrupt user
  	 * memory for SG_IO commands.
  	 */
  	if (unlikely(blk_rq_is_passthrough(scmd->request)))
  		goto invalid_opcode;
  
  	if (unlikely(scmd->cmd_len < 16)) {
  		fp = 15;
  		goto invalid_fld;
  	}
  	scsi_16_lba_len(cdb, &block, &n_block);
  
  	if (!unmap ||
  	    (dev->horkage & ATA_HORKAGE_NOTRIM) ||
  	    !ata_id_has_trim(dev->id)) {
  		fp = 1;
  		bp = 3;
  		goto invalid_fld;
  	}
  	/* If the request is too large the cmd is invalid */
  	if (n_block > 0xffff * trmax) {
  		fp = 2;
  		goto invalid_fld;
  	}
  
  	/*
  	 * WRITE SAME always has a sector sized buffer as payload, this
  	 * should never be a multiple entry S/G list.
  	 */
  	if (!scsi_sg_count(scmd))
  		goto invalid_param_len;
  
  	/*
  	 * size must match sector size in bytes
  	 * For DATA SET MANAGEMENT TRIM in ACS-2 nsect (aka count)
  	 * is defined as number of 512 byte blocks to be transferred.
  	 */
  
  	size = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);
  	if (size != len)
  		goto invalid_param_len;
  
  	if (ata_ncq_enabled(dev) && ata_fpdma_dsm_supported(dev)) {
  		/* Newer devices support queued TRIM commands */
  		tf->protocol = ATA_PROT_NCQ;
  		tf->command = ATA_CMD_FPDMA_SEND;
  		tf->hob_nsect = ATA_SUBCMD_FPDMA_SEND_DSM & 0x1f;
  		tf->nsect = qc->tag << 3;
  		tf->hob_feature = (size / 512) >> 8;
  		tf->feature = size / 512;
  
  		tf->auxiliary = 1;
  	} else {
  		tf->protocol = ATA_PROT_DMA;
  		tf->hob_feature = 0;
  		tf->feature = ATA_DSM_TRIM;
  		tf->hob_nsect = (size / 512) >> 8;
  		tf->nsect = size / 512;
  		tf->command = ATA_CMD_DSM;
  	}
  
  	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48 |
  		     ATA_TFLAG_WRITE;
  
  	ata_qc_set_pc_nbytes(qc);
  
  	return 0;
  
  invalid_fld:
  	ata_scsi_set_invalid_field(dev, scmd, fp, bp);
  	return 1;
  invalid_param_len:
  	/* "Parameter list length error" */
  	ata_scsi_set_sense(dev, scmd, ILLEGAL_REQUEST, 0x1a, 0x0);
  	return 1;
  invalid_opcode:
  	/* "Invalid command operation code" */
  	ata_scsi_set_sense(dev, scmd, ILLEGAL_REQUEST, 0x20, 0x0);
  	return 1;
  }
  
  /**
   *	ata_scsiop_maint_in - Simulate a subset of MAINTENANCE_IN
   *	@args: device MAINTENANCE_IN data / SCSI command of interest.
   *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
   *
   *	Yields a subset to satisfy scsi_report_opcode()
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
  {
  	struct ata_device *dev = args->dev;
  	u8 *cdb = args->cmd->cmnd;
  	u8 supported = 0;
  	unsigned int err = 0;
  
  	if (cdb[2] != 1) {
  		ata_dev_warn(dev, "invalid command format %d\n", cdb[2]);
  		err = 2;
  		goto out;
  	}
  	switch (cdb[3]) {
  	case INQUIRY:
  	case MODE_SENSE:
  	case MODE_SENSE_10:
  	case READ_CAPACITY:
  	case SERVICE_ACTION_IN_16:
  	case REPORT_LUNS:
  	case REQUEST_SENSE:
  	case SYNCHRONIZE_CACHE:
  	case REZERO_UNIT:
  	case SEEK_6:
  	case SEEK_10:
  	case TEST_UNIT_READY:
  	case SEND_DIAGNOSTIC:
  	case MAINTENANCE_IN:
  	case READ_6:
  	case READ_10:
  	case READ_16:
  	case WRITE_6:
  	case WRITE_10:
  	case WRITE_16:
  	case ATA_12:
  	case ATA_16:
  	case VERIFY:
  	case VERIFY_16:
  	case MODE_SELECT:
  	case MODE_SELECT_10:
  	case START_STOP:
  		supported = 3;
  		break;
  	case ZBC_IN:
  	case ZBC_OUT:
  		if (ata_id_zoned_cap(dev->id) ||
  		    dev->class == ATA_DEV_ZAC)
  			supported = 3;
  		break;
  	case SECURITY_PROTOCOL_IN:
  	case SECURITY_PROTOCOL_OUT:
  		if (dev->flags & ATA_DFLAG_TRUSTED)
  			supported = 3;
  		break;
  	default:
  		break;
  	}
  out:
  	rbuf[1] = supported; /* supported */
  	return err;
  }
  
  /**
   *	ata_scsi_report_zones_complete - convert ATA output
   *	@qc: command structure returning the data
   *
   *	Convert T-13 little-endian field representation into
   *	T-10 big-endian field representation.
   *	What a mess.
   */
  static void ata_scsi_report_zones_complete(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	struct sg_mapping_iter miter;
  	unsigned long flags;
  	unsigned int bytes = 0;
  
  	sg_miter_start(&miter, scsi_sglist(scmd), scsi_sg_count(scmd),
  		       SG_MITER_TO_SG | SG_MITER_ATOMIC);
  
  	local_irq_save(flags);
  	while (sg_miter_next(&miter)) {
  		unsigned int offset = 0;
  
  		if (bytes == 0) {
  			char *hdr;
  			u32 list_length;
  			u64 max_lba, opt_lba;
  			u16 same;
  
  			/* Swizzle header */
  			hdr = miter.addr;
  			list_length = get_unaligned_le32(&hdr[0]);
  			same = get_unaligned_le16(&hdr[4]);
  			max_lba = get_unaligned_le64(&hdr[8]);
  			opt_lba = get_unaligned_le64(&hdr[16]);
  			put_unaligned_be32(list_length, &hdr[0]);
  			hdr[4] = same & 0xf;
  			put_unaligned_be64(max_lba, &hdr[8]);
  			put_unaligned_be64(opt_lba, &hdr[16]);
  			offset += 64;
  			bytes += 64;
  		}
  		while (offset < miter.length) {
  			char *rec;
  			u8 cond, type, non_seq, reset;
  			u64 size, start, wp;
  
  			/* Swizzle zone descriptor */
  			rec = miter.addr + offset;
  			type = rec[0] & 0xf;
  			cond = (rec[1] >> 4) & 0xf;
  			non_seq = (rec[1] & 2);
  			reset = (rec[1] & 1);
  			size = get_unaligned_le64(&rec[8]);
  			start = get_unaligned_le64(&rec[16]);
  			wp = get_unaligned_le64(&rec[24]);
  			rec[0] = type;
  			rec[1] = (cond << 4) | non_seq | reset;
  			put_unaligned_be64(size, &rec[8]);
  			put_unaligned_be64(start, &rec[16]);
  			put_unaligned_be64(wp, &rec[24]);
  			WARN_ON(offset + 64 > miter.length);
  			offset += 64;
  			bytes += 64;
  		}
  	}
  	sg_miter_stop(&miter);
  	local_irq_restore(flags);
  
  	ata_scsi_qc_complete(qc);
  }
  
  static unsigned int ata_scsi_zbc_in_xlat(struct ata_queued_cmd *qc)
  {
  	struct ata_taskfile *tf = &qc->tf;
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	const u8 *cdb = scmd->cmnd;
  	u16 sect, fp = (u16)-1;
  	u8 sa, options, bp = 0xff;
  	u64 block;
  	u32 n_block;
  
  	if (unlikely(scmd->cmd_len < 16)) {
  		ata_dev_warn(qc->dev, "invalid cdb length %d\n",
  			     scmd->cmd_len);
  		fp = 15;
  		goto invalid_fld;
  	}
  	scsi_16_lba_len(cdb, &block, &n_block);
  	if (n_block != scsi_bufflen(scmd)) {
  		ata_dev_warn(qc->dev, "non-matching transfer count (%d/%d)\n",
  			     n_block, scsi_bufflen(scmd));
  		goto invalid_param_len;
  	}
  	sa = cdb[1] & 0x1f;
  	if (sa != ZI_REPORT_ZONES) {
  		ata_dev_warn(qc->dev, "invalid service action %d\n", sa);
  		fp = 1;
  		goto invalid_fld;
  	}
  	/*
  	 * ZAC allows only for transfers in 512 byte blocks,
  	 * and uses a 16 bit value for the transfer count.
  	 */
  	if ((n_block / 512) > 0xffff || n_block < 512 || (n_block % 512)) {
  		ata_dev_warn(qc->dev, "invalid transfer count %d\n", n_block);
  		goto invalid_param_len;
  	}
  	sect = n_block / 512;
  	options = cdb[14] & 0xbf;
  
  	if (ata_ncq_enabled(qc->dev) &&
  	    ata_fpdma_zac_mgmt_in_supported(qc->dev)) {
  		tf->protocol = ATA_PROT_NCQ;
  		tf->command = ATA_CMD_FPDMA_RECV;
  		tf->hob_nsect = ATA_SUBCMD_FPDMA_RECV_ZAC_MGMT_IN & 0x1f;
  		tf->nsect = qc->tag << 3;
  		tf->feature = sect & 0xff;
  		tf->hob_feature = (sect >> 8) & 0xff;
  		tf->auxiliary = ATA_SUBCMD_ZAC_MGMT_IN_REPORT_ZONES | (options << 8);
  	} else {
  		tf->command = ATA_CMD_ZAC_MGMT_IN;
  		tf->feature = ATA_SUBCMD_ZAC_MGMT_IN_REPORT_ZONES;
  		tf->protocol = ATA_PROT_DMA;
  		tf->hob_feature = options;
  		tf->hob_nsect = (sect >> 8) & 0xff;
  		tf->nsect = sect & 0xff;
  	}
  	tf->device = ATA_LBA;
  	tf->lbah = (block >> 16) & 0xff;
  	tf->lbam = (block >> 8) & 0xff;
  	tf->lbal = block & 0xff;
  	tf->hob_lbah = (block >> 40) & 0xff;
  	tf->hob_lbam = (block >> 32) & 0xff;
  	tf->hob_lbal = (block >> 24) & 0xff;
  
  	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
  	qc->flags |= ATA_QCFLAG_RESULT_TF;
  
  	ata_qc_set_pc_nbytes(qc);
  
  	qc->complete_fn = ata_scsi_report_zones_complete;
  
  	return 0;
  
  invalid_fld:
  	ata_scsi_set_invalid_field(qc->dev, scmd, fp, bp);
  	return 1;
  
  invalid_param_len:
  	/* "Parameter list length error" */
  	ata_scsi_set_sense(qc->dev, scmd, ILLEGAL_REQUEST, 0x1a, 0x0);
  	return 1;
  }
  
  static unsigned int ata_scsi_zbc_out_xlat(struct ata_queued_cmd *qc)
  {
  	struct ata_taskfile *tf = &qc->tf;
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	struct ata_device *dev = qc->dev;
  	const u8 *cdb = scmd->cmnd;
  	u8 all, sa;
  	u64 block;
  	u32 n_block;
  	u16 fp = (u16)-1;
  
  	if (unlikely(scmd->cmd_len < 16)) {
  		fp = 15;
  		goto invalid_fld;
  	}
  
  	sa = cdb[1] & 0x1f;
  	if ((sa != ZO_CLOSE_ZONE) && (sa != ZO_FINISH_ZONE) &&
  	    (sa != ZO_OPEN_ZONE) && (sa != ZO_RESET_WRITE_POINTER)) {
  		fp = 1;
  		goto invalid_fld;
  	}
  
  	scsi_16_lba_len(cdb, &block, &n_block);
  	if (n_block) {
  		/*
  		 * ZAC MANAGEMENT OUT doesn't define any length
  		 */
  		goto invalid_param_len;
  	}
  	if (block > dev->n_sectors)
  		goto out_of_range;
  
  	all = cdb[14] & 0x1;
  
  	if (ata_ncq_enabled(qc->dev) &&
  	    ata_fpdma_zac_mgmt_out_supported(qc->dev)) {
  		tf->protocol = ATA_PROT_NCQ_NODATA;
  		tf->command = ATA_CMD_NCQ_NON_DATA;
  		tf->feature = ATA_SUBCMD_NCQ_NON_DATA_ZAC_MGMT_OUT;
  		tf->nsect = qc->tag << 3;
  		tf->auxiliary = sa | ((u16)all << 8);
  	} else {
  		tf->protocol = ATA_PROT_NODATA;
  		tf->command = ATA_CMD_ZAC_MGMT_OUT;
  		tf->feature = sa;
  		tf->hob_feature = all;
  	}
  	tf->lbah = (block >> 16) & 0xff;
  	tf->lbam = (block >> 8) & 0xff;
  	tf->lbal = block & 0xff;
  	tf->hob_lbah = (block >> 40) & 0xff;
  	tf->hob_lbam = (block >> 32) & 0xff;
  	tf->hob_lbal = (block >> 24) & 0xff;
  	tf->device = ATA_LBA;
  	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
  
  	return 0;
  
   invalid_fld:
  	ata_scsi_set_invalid_field(qc->dev, scmd, fp, 0xff);
  	return 1;
   out_of_range:
  	/* "Logical Block Address out of range" */
  	ata_scsi_set_sense(qc->dev, scmd, ILLEGAL_REQUEST, 0x21, 0x00);
  	return 1;
  invalid_param_len:
  	/* "Parameter list length error" */
  	ata_scsi_set_sense(qc->dev, scmd, ILLEGAL_REQUEST, 0x1a, 0x0);
  	return 1;
  }
  
  /**
   *	ata_mselect_caching - Simulate MODE SELECT for caching info page
   *	@qc: Storage for translated ATA taskfile
   *	@buf: input buffer
   *	@len: number of valid bytes in the input buffer
   *	@fp: out parameter for the failed field on error
   *
   *	Prepare a taskfile to modify caching information for the device.
   *
   *	LOCKING:
   *	None.
   */
  static int ata_mselect_caching(struct ata_queued_cmd *qc,
  			       const u8 *buf, int len, u16 *fp)
  {
  	struct ata_taskfile *tf = &qc->tf;
  	struct ata_device *dev = qc->dev;
  	u8 mpage[CACHE_MPAGE_LEN];
  	u8 wce;
  	int i;
  
  	/*
  	 * The first two bytes of def_cache_mpage are a header, so offsets
  	 * in mpage are off by 2 compared to buf.  Same for len.
  	 */
  
  	if (len != CACHE_MPAGE_LEN - 2) {
  		if (len < CACHE_MPAGE_LEN - 2)
  			*fp = len;
  		else
  			*fp = CACHE_MPAGE_LEN - 2;
  		return -EINVAL;
  	}
  
  	wce = buf[0] & (1 << 2);
  
  	/*
  	 * Check that read-only bits are not modified.
  	 */
  	ata_msense_caching(dev->id, mpage, false);
  	for (i = 0; i < CACHE_MPAGE_LEN - 2; i++) {
  		if (i == 0)
  			continue;
  		if (mpage[i + 2] != buf[i]) {
  			*fp = i;
  			return -EINVAL;
  		}
  	}
  
  	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
  	tf->protocol = ATA_PROT_NODATA;
  	tf->nsect = 0;
  	tf->command = ATA_CMD_SET_FEATURES;
  	tf->feature = wce ? SETFEATURES_WC_ON : SETFEATURES_WC_OFF;
  	return 0;
  }
  
  /**
   *	ata_mselect_control - Simulate MODE SELECT for control page
   *	@qc: Storage for translated ATA taskfile
   *	@buf: input buffer
   *	@len: number of valid bytes in the input buffer
   *	@fp: out parameter for the failed field on error
   *
   *	Prepare a taskfile to modify caching information for the device.
   *
   *	LOCKING:
   *	None.
   */
  static int ata_mselect_control(struct ata_queued_cmd *qc,
  			       const u8 *buf, int len, u16 *fp)
  {
  	struct ata_device *dev = qc->dev;
  	u8 mpage[CONTROL_MPAGE_LEN];
  	u8 d_sense;
  	int i;
  
  	/*
  	 * The first two bytes of def_control_mpage are a header, so offsets
  	 * in mpage are off by 2 compared to buf.  Same for len.
  	 */
  
  	if (len != CONTROL_MPAGE_LEN - 2) {
  		if (len < CONTROL_MPAGE_LEN - 2)
  			*fp = len;
  		else
  			*fp = CONTROL_MPAGE_LEN - 2;
  		return -EINVAL;
  	}
  
  	d_sense = buf[0] & (1 << 2);
  
  	/*
  	 * Check that read-only bits are not modified.
  	 */
  	ata_msense_control(dev, mpage, false);
  	for (i = 0; i < CONTROL_MPAGE_LEN - 2; i++) {
  		if (i == 0)
  			continue;
  		if (mpage[2 + i] != buf[i]) {
  			*fp = i;
  			return -EINVAL;
  		}
  	}
  	if (d_sense & (1 << 2))
  		dev->flags |= ATA_DFLAG_D_SENSE;
  	else
  		dev->flags &= ~ATA_DFLAG_D_SENSE;
  	return 0;
  }
  
  /**
   *	ata_scsi_mode_select_xlat - Simulate MODE SELECT 6, 10 commands
   *	@qc: Storage for translated ATA taskfile
   *
   *	Converts a MODE SELECT command to an ATA SET FEATURES taskfile.
   *	Assume this is invoked for direct access devices (e.g. disks) only.
   *	There should be no block descriptor for other device types.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	const u8 *cdb = scmd->cmnd;
  	const u8 *p;
  	u8 pg, spg;
  	unsigned six_byte, pg_len, hdr_len, bd_len;
  	int len;
  	u16 fp = (u16)-1;
  	u8 bp = 0xff;
  
  	VPRINTK("ENTER\n");
  
  	six_byte = (cdb[0] == MODE_SELECT);
  	if (six_byte) {
  		if (scmd->cmd_len < 5) {
  			fp = 4;
  			goto invalid_fld;
  		}
  
  		len = cdb[4];
  		hdr_len = 4;
  	} else {
  		if (scmd->cmd_len < 9) {
  			fp = 8;
  			goto invalid_fld;
  		}
  
  		len = (cdb[7] << 8) + cdb[8];
  		hdr_len = 8;
  	}
  
  	/* We only support PF=1, SP=0.  */
  	if ((cdb[1] & 0x11) != 0x10) {
  		fp = 1;
  		bp = (cdb[1] & 0x01) ? 1 : 5;
  		goto invalid_fld;
  	}
  
  	/* Test early for possible overrun.  */
  	if (!scsi_sg_count(scmd) || scsi_sglist(scmd)->length < len)
  		goto invalid_param_len;
  
  	p = page_address(sg_page(scsi_sglist(scmd)));
  
  	/* Move past header and block descriptors.  */
  	if (len < hdr_len)
  		goto invalid_param_len;
  
  	if (six_byte)
  		bd_len = p[3];
  	else
  		bd_len = (p[6] << 8) + p[7];
  
  	len -= hdr_len;
  	p += hdr_len;
  	if (len < bd_len)
  		goto invalid_param_len;
  	if (bd_len != 0 && bd_len != 8) {
  		fp = (six_byte) ? 3 : 6;
  		fp += bd_len + hdr_len;
  		goto invalid_param;
  	}
  
  	len -= bd_len;
  	p += bd_len;
  	if (len == 0)
  		goto skip;
  
  	/* Parse both possible formats for the mode page headers.  */
  	pg = p[0] & 0x3f;
  	if (p[0] & 0x40) {
  		if (len < 4)
  			goto invalid_param_len;
  
  		spg = p[1];
  		pg_len = (p[2] << 8) | p[3];
  		p += 4;
  		len -= 4;
  	} else {
  		if (len < 2)
  			goto invalid_param_len;
  
  		spg = 0;
  		pg_len = p[1];
  		p += 2;
  		len -= 2;
  	}
  
  	/*
  	 * No mode subpages supported (yet) but asking for _all_
  	 * subpages may be valid
  	 */
  	if (spg && (spg != ALL_SUB_MPAGES)) {
  		fp = (p[0] & 0x40) ? 1 : 0;
  		fp += hdr_len + bd_len;
  		goto invalid_param;
  	}
  	if (pg_len > len)
  		goto invalid_param_len;
  
  	switch (pg) {
  	case CACHE_MPAGE:
  		if (ata_mselect_caching(qc, p, pg_len, &fp) < 0) {
  			fp += hdr_len + bd_len;
  			goto invalid_param;
  		}
  		break;
  	case CONTROL_MPAGE:
  		if (ata_mselect_control(qc, p, pg_len, &fp) < 0) {
  			fp += hdr_len + bd_len;
  			goto invalid_param;
  		} else {
  			goto skip; /* No ATA command to send */
  		}
  		break;
  	default:		/* invalid page code */
  		fp = bd_len + hdr_len;
  		goto invalid_param;
  	}
  
  	/*
  	 * Only one page has changeable data, so we only support setting one
  	 * page at a time.
  	 */
  	if (len > pg_len)
  		goto invalid_param;
  
  	return 0;
  
   invalid_fld:
  	ata_scsi_set_invalid_field(qc->dev, scmd, fp, bp);
  	return 1;
  
   invalid_param:
  	ata_scsi_set_invalid_parameter(qc->dev, scmd, fp);
  	return 1;
  
   invalid_param_len:
  	/* "Parameter list length error" */
  	ata_scsi_set_sense(qc->dev, scmd, ILLEGAL_REQUEST, 0x1a, 0x0);
  	return 1;
  
   skip:
  	scmd->result = SAM_STAT_GOOD;
  	return 1;
  }
  
  static u8 ata_scsi_trusted_op(u32 len, bool send, bool dma)
  {
  	if (len == 0)
  		return ATA_CMD_TRUSTED_NONDATA;
  	else if (send)
  		return dma ? ATA_CMD_TRUSTED_SND_DMA : ATA_CMD_TRUSTED_SND;
  	else
  		return dma ? ATA_CMD_TRUSTED_RCV_DMA : ATA_CMD_TRUSTED_RCV;
  }
  
  static unsigned int ata_scsi_security_inout_xlat(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	const u8 *cdb = scmd->cmnd;
  	struct ata_taskfile *tf = &qc->tf;
  	u8 secp = cdb[1];
  	bool send = (cdb[0] == SECURITY_PROTOCOL_OUT);
  	u16 spsp = get_unaligned_be16(&cdb[2]);
  	u32 len = get_unaligned_be32(&cdb[6]);
  	bool dma = !(qc->dev->flags & ATA_DFLAG_PIO);
  
  	/*
  	 * We don't support the ATA "security" protocol.
  	 */
  	if (secp == 0xef) {
  		ata_scsi_set_invalid_field(qc->dev, scmd, 1, 0);
  		return 1;
  	}
  
  	if (cdb[4] & 7) { /* INC_512 */
  		if (len > 0xffff) {
  			ata_scsi_set_invalid_field(qc->dev, scmd, 6, 0);
  			return 1;
  		}
  	} else {
  		if (len > 0x01fffe00) {
  			ata_scsi_set_invalid_field(qc->dev, scmd, 6, 0);
  			return 1;
  		}
  
  		/* convert to the sector-based ATA addressing */
  		len = (len + 511) / 512;
  	}
  
  	tf->protocol = dma ? ATA_PROT_DMA : ATA_PROT_PIO;
  	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR | ATA_TFLAG_LBA;
  	if (send)
  		tf->flags |= ATA_TFLAG_WRITE;
  	tf->command = ata_scsi_trusted_op(len, send, dma);
  	tf->feature = secp;
  	tf->lbam = spsp & 0xff;
  	tf->lbah = spsp >> 8;
  
  	if (len) {
  		tf->nsect = len & 0xff;
  		tf->lbal = len >> 8;
  	} else {
  		if (!send)
  			tf->lbah = (1 << 7);
  	}
  
  	ata_qc_set_pc_nbytes(qc);
  	return 0;
  }
  
  /**
   *	ata_scsi_var_len_cdb_xlat - SATL variable length CDB to Handler
   *	@qc: Command to be translated
   *
   *	Translate a SCSI variable length CDB to specified commands.
   *	It checks a service action value in CDB to call corresponding handler.
   *
   *	RETURNS:
   *	Zero on success, non-zero on failure
   *
   */
  static unsigned int ata_scsi_var_len_cdb_xlat(struct ata_queued_cmd *qc)
  {
  	struct scsi_cmnd *scmd = qc->scsicmd;
  	const u8 *cdb = scmd->cmnd;
  	const u16 sa = get_unaligned_be16(&cdb[8]);
  
  	/*
  	 * if service action represents a ata pass-thru(32) command,
  	 * then pass it to ata_scsi_pass_thru handler.
  	 */
  	if (sa == ATA_32)
  		return ata_scsi_pass_thru(qc);
  
  	/* unsupported service action */
  	return 1;
  }
  
  /**
   *	ata_get_xlat_func - check if SCSI to ATA translation is possible
   *	@dev: ATA device
   *	@cmd: SCSI command opcode to consider
   *
   *	Look up the SCSI command given, and determine whether the
   *	SCSI command is to be translated or simulated.
   *
   *	RETURNS:
   *	Pointer to translation function if possible, %NULL if not.
   */
  
  static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
  {
  	switch (cmd) {
  	case READ_6:
  	case READ_10:
  	case READ_16:
  
  	case WRITE_6:
  	case WRITE_10:
  	case WRITE_16:
  		return ata_scsi_rw_xlat;
  
  	case WRITE_SAME_16:
  		return ata_scsi_write_same_xlat;
  
  	case SYNCHRONIZE_CACHE:
  		if (ata_try_flush_cache(dev))
  			return ata_scsi_flush_xlat;
  		break;
  
  	case VERIFY:
  	case VERIFY_16:
  		return ata_scsi_verify_xlat;
  
  	case ATA_12:
  	case ATA_16:
  		return ata_scsi_pass_thru;
  
  	case VARIABLE_LENGTH_CMD:
  		return ata_scsi_var_len_cdb_xlat;
  
  	case MODE_SELECT:
  	case MODE_SELECT_10:
  		return ata_scsi_mode_select_xlat;
  		break;
  
  	case ZBC_IN:
  		return ata_scsi_zbc_in_xlat;
  
  	case ZBC_OUT:
  		return ata_scsi_zbc_out_xlat;
  
  	case SECURITY_PROTOCOL_IN:
  	case SECURITY_PROTOCOL_OUT:
  		if (!(dev->flags & ATA_DFLAG_TRUSTED))
  			break;
  		return ata_scsi_security_inout_xlat;
  
  	case START_STOP:
  		return ata_scsi_start_stop_xlat;
  	}
  
  	return NULL;
  }
  
  /**
   *	ata_scsi_dump_cdb - dump SCSI command contents to dmesg
   *	@ap: ATA port to which the command was being sent
   *	@cmd: SCSI command to dump
   *
   *	Prints the contents of a SCSI command via printk().
   */
  
  static inline void ata_scsi_dump_cdb(struct ata_port *ap,
  				     struct scsi_cmnd *cmd)
  {
  #ifdef ATA_DEBUG
  	struct scsi_device *scsidev = cmd->device;
  
  	DPRINTK("CDB (%u:%d,%d,%d) %9ph\n",
  		ap->print_id,
  		scsidev->channel, scsidev->id, scsidev->lun,
  		cmd->cmnd);
  #endif
  }
  
  static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
  				      struct ata_device *dev)
  {
  	u8 scsi_op = scmd->cmnd[0];
  	ata_xlat_func_t xlat_func;
  	int rc = 0;
  
  	if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
  		if (unlikely(!scmd->cmd_len || scmd->cmd_len > dev->cdb_len))
  			goto bad_cdb_len;
  
  		xlat_func = ata_get_xlat_func(dev, scsi_op);
  	} else {
  		if (unlikely(!scmd->cmd_len))
  			goto bad_cdb_len;
  
  		xlat_func = NULL;
  		if (likely((scsi_op != ATA_16) || !atapi_passthru16)) {
  			/* relay SCSI command to ATAPI device */
  			int len = COMMAND_SIZE(scsi_op);
  			if (unlikely(len > scmd->cmd_len || len > dev->cdb_len))
  				goto bad_cdb_len;
  
  			xlat_func = atapi_xlat;
  		} else {
  			/* ATA_16 passthru, treat as an ATA command */
  			if (unlikely(scmd->cmd_len > 16))
  				goto bad_cdb_len;
  
  			xlat_func = ata_get_xlat_func(dev, scsi_op);
  		}
  	}
  
  	if (xlat_func)
  		rc = ata_scsi_translate(dev, scmd, xlat_func);
  	else
  		ata_scsi_simulate(dev, scmd);
  
  	return rc;
  
   bad_cdb_len:
  	DPRINTK("bad CDB len=%u, scsi_op=0x%02x, max=%u\n",
  		scmd->cmd_len, scsi_op, dev->cdb_len);
  	scmd->result = DID_ERROR << 16;
  	scmd->scsi_done(scmd);
  	return 0;
  }
  
  /**
   *	ata_scsi_queuecmd - Issue SCSI cdb to libata-managed device
   *	@shost: SCSI host of command to be sent
   *	@cmd: SCSI command to be sent
   *
   *	In some cases, this function translates SCSI commands into
   *	ATA taskfiles, and queues the taskfiles to be sent to
   *	hardware.  In other cases, this function simulates a
   *	SCSI device by evaluating and responding to certain
   *	SCSI commands.  This creates the overall effect of
   *	ATA and ATAPI devices appearing as SCSI devices.
   *
   *	LOCKING:
   *	ATA host lock
   *
   *	RETURNS:
   *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
   *	0 otherwise.
   */
  int ata_scsi_queuecmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
  {
  	struct ata_port *ap;
  	struct ata_device *dev;
  	struct scsi_device *scsidev = cmd->device;
  	int rc = 0;
  	unsigned long irq_flags;
  
  	ap = ata_shost_to_port(shost);
  
  	spin_lock_irqsave(ap->lock, irq_flags);
  
  	ata_scsi_dump_cdb(ap, cmd);
  
  	dev = ata_scsi_find_dev(ap, scsidev);
  	if (likely(dev))
  		rc = __ata_scsi_queuecmd(cmd, dev);
  	else {
  		cmd->result = (DID_BAD_TARGET << 16);
  		cmd->scsi_done(cmd);
  	}
  
  	spin_unlock_irqrestore(ap->lock, irq_flags);
  
  	return rc;
  }
  
  /**
   *	ata_scsi_simulate - simulate SCSI command on ATA device
   *	@dev: the target device
   *	@cmd: SCSI command being sent to device.
   *
   *	Interprets and directly executes a select list of SCSI commands
   *	that can be handled internally.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   */
  
  void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd)
  {
  	struct ata_scsi_args args;
  	const u8 *scsicmd = cmd->cmnd;
  	u8 tmp8;
  
  	args.dev = dev;
  	args.id = dev->id;
  	args.cmd = cmd;
  
  	switch(scsicmd[0]) {
  	case INQUIRY:
  		if (scsicmd[1] & 2)		   /* is CmdDt set?  */
  			ata_scsi_set_invalid_field(dev, cmd, 1, 0xff);
  		else if ((scsicmd[1] & 1) == 0)    /* is EVPD clear? */
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_std);
  		else switch (scsicmd[2]) {
  		case 0x00:
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_00);
  			break;
  		case 0x80:
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_80);
  			break;
  		case 0x83:
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_83);
  			break;
  		case 0x89:
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_89);
  			break;
  		case 0xb0:
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_b0);
  			break;
  		case 0xb1:
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_b1);
  			break;
  		case 0xb2:
  			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_b2);
  			break;
  		case 0xb6:
  			if (dev->flags & ATA_DFLAG_ZAC) {
  				ata_scsi_rbuf_fill(&args, ata_scsiop_inq_b6);
  				break;
  			}
  			/* Fallthrough */
  		default:
  			ata_scsi_set_invalid_field(dev, cmd, 2, 0xff);
  			break;
  		}
  		break;
  
  	case MODE_SENSE:
  	case MODE_SENSE_10:
  		ata_scsi_rbuf_fill(&args, ata_scsiop_mode_sense);
  		break;
  
  	case READ_CAPACITY:
  		ata_scsi_rbuf_fill(&args, ata_scsiop_read_cap);
  		break;
  
  	case SERVICE_ACTION_IN_16:
  		if ((scsicmd[1] & 0x1f) == SAI_READ_CAPACITY_16)
  			ata_scsi_rbuf_fill(&args, ata_scsiop_read_cap);
  		else
  			ata_scsi_set_invalid_field(dev, cmd, 1, 0xff);
  		break;
  
  	case REPORT_LUNS:
  		ata_scsi_rbuf_fill(&args, ata_scsiop_report_luns);
  		break;
  
  	case REQUEST_SENSE:
  		ata_scsi_set_sense(dev, cmd, 0, 0, 0);
  		cmd->result = (DRIVER_SENSE << 24);
  		break;
  
  	/* if we reach this, then writeback caching is disabled,
  	 * turning this into a no-op.
  	 */
  	case SYNCHRONIZE_CACHE:
  		/* fall through */
  
  	/* no-op's, complete with success */
  	case REZERO_UNIT:
  	case SEEK_6:
  	case SEEK_10:
  	case TEST_UNIT_READY:
  		break;
  
  	case SEND_DIAGNOSTIC:
  		tmp8 = scsicmd[1] & ~(1 << 3);
  		if (tmp8 != 0x4 || scsicmd[3] || scsicmd[4])
  			ata_scsi_set_invalid_field(dev, cmd, 1, 0xff);
  		break;
  
  	case MAINTENANCE_IN:
  		if (scsicmd[1] == MI_REPORT_SUPPORTED_OPERATION_CODES)
  			ata_scsi_rbuf_fill(&args, ata_scsiop_maint_in);
  		else
  			ata_scsi_set_invalid_field(dev, cmd, 1, 0xff);
  		break;
  
  	/* all other commands */
  	default:
  		ata_scsi_set_sense(dev, cmd, ILLEGAL_REQUEST, 0x20, 0x0);
  		/* "Invalid command operation code" */
  		break;
  	}
  
  	cmd->scsi_done(cmd);
  }
  
  int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
  {
  	int i, rc;
  
  	for (i = 0; i < host->n_ports; i++) {
  		struct ata_port *ap = host->ports[i];
  		struct Scsi_Host *shost;
  
  		rc = -ENOMEM;
  		shost = scsi_host_alloc(sht, sizeof(struct ata_port *));
  		if (!shost)
  			goto err_alloc;
  
  		shost->eh_noresume = 1;
  		*(struct ata_port **)&shost->hostdata[0] = ap;
  		ap->scsi_host = shost;
  
  		shost->transportt = ata_scsi_transport_template;
  		shost->unique_id = ap->print_id;
  		shost->max_id = 16;
  		shost->max_lun = 1;
  		shost->max_channel = 1;
  		shost->max_cmd_len = 32;
  
  		/* Schedule policy is determined by ->qc_defer()
  		 * callback and it needs to see every deferred qc.
  		 * Set host_blocked to 1 to prevent SCSI midlayer from
  		 * automatically deferring requests.
  		 */
  		shost->max_host_blocked = 1;
  
  		rc = scsi_add_host_with_dma(ap->scsi_host,
  						&ap->tdev, ap->host->dev);
  		if (rc)
  			goto err_add;
  	}
  
  	return 0;
  
   err_add:
  	scsi_host_put(host->ports[i]->scsi_host);
   err_alloc:
  	while (--i >= 0) {
  		struct Scsi_Host *shost = host->ports[i]->scsi_host;
  
  		scsi_remove_host(shost);
  		scsi_host_put(shost);
  	}
  	return rc;
  }
  
  void ata_scsi_scan_host(struct ata_port *ap, int sync)
  {
  	int tries = 5;
  	struct ata_device *last_failed_dev = NULL;
  	struct ata_link *link;
  	struct ata_device *dev;
  
   repeat:
  	ata_for_each_link(link, ap, EDGE) {
  		ata_for_each_dev(dev, link, ENABLED) {
  			struct scsi_device *sdev;
  			int channel = 0, id = 0;
  
  			if (dev->sdev)
  				continue;
  
  			if (ata_is_host_link(link))
  				id = dev->devno;
  			else
  				channel = link->pmp;
  
  			sdev = __scsi_add_device(ap->scsi_host, channel, id, 0,
  						 NULL);
  			if (!IS_ERR(sdev)) {
  				dev->sdev = sdev;
  				scsi_device_put(sdev);
  			} else {
  				dev->sdev = NULL;
  			}
  		}
  	}
  
  	/* If we scanned while EH was in progress or allocation
  	 * failure occurred, scan would have failed silently.  Check
  	 * whether all devices are attached.
  	 */
  	ata_for_each_link(link, ap, EDGE) {
  		ata_for_each_dev(dev, link, ENABLED) {
  			if (!dev->sdev)
  				goto exit_loop;
  		}
  	}
   exit_loop:
  	if (!link)
  		return;
  
  	/* we're missing some SCSI devices */
  	if (sync) {
  		/* If caller requested synchrnous scan && we've made
  		 * any progress, sleep briefly and repeat.
  		 */
  		if (dev != last_failed_dev) {
  			msleep(100);
  			last_failed_dev = dev;
  			goto repeat;
  		}
  
  		/* We might be failing to detect boot device, give it
  		 * a few more chances.
  		 */
  		if (--tries) {
  			msleep(100);
  			goto repeat;
  		}
  
  		ata_port_err(ap,
  			     "WARNING: synchronous SCSI scan failed without making any progress, switching to async\n");
  	}
  
  	queue_delayed_work(system_long_wq, &ap->hotplug_task,
  			   round_jiffies_relative(HZ));
  }
  
  /**
   *	ata_scsi_offline_dev - offline attached SCSI device
   *	@dev: ATA device to offline attached SCSI device for
   *
   *	This function is called from ata_eh_hotplug() and responsible
   *	for taking the SCSI device attached to @dev offline.  This
   *	function is called with host lock which protects dev->sdev
   *	against clearing.
   *
   *	LOCKING:
   *	spin_lock_irqsave(host lock)
   *
   *	RETURNS:
   *	1 if attached SCSI device exists, 0 otherwise.
   */
  int ata_scsi_offline_dev(struct ata_device *dev)
  {
  	if (dev->sdev) {
  		scsi_device_set_state(dev->sdev, SDEV_OFFLINE);
  		return 1;
  	}
  	return 0;
  }
  
  /**
   *	ata_scsi_remove_dev - remove attached SCSI device
   *	@dev: ATA device to remove attached SCSI device for
   *
   *	This function is called from ata_eh_scsi_hotplug() and
   *	responsible for removing the SCSI device attached to @dev.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep).
   */
  static void ata_scsi_remove_dev(struct ata_device *dev)
  {
  	struct ata_port *ap = dev->link->ap;
  	struct scsi_device *sdev;
  	unsigned long flags;
  
  	/* Alas, we need to grab scan_mutex to ensure SCSI device
  	 * state doesn't change underneath us and thus
  	 * scsi_device_get() always succeeds.  The mutex locking can
  	 * be removed if there is __scsi_device_get() interface which
  	 * increments reference counts regardless of device state.
  	 */
  	mutex_lock(&ap->scsi_host->scan_mutex);
  	spin_lock_irqsave(ap->lock, flags);
  
  	/* clearing dev->sdev is protected by host lock */
  	sdev = dev->sdev;
  	dev->sdev = NULL;
  
  	if (sdev) {
  		/* If user initiated unplug races with us, sdev can go
  		 * away underneath us after the host lock and
  		 * scan_mutex are released.  Hold onto it.
  		 */
  		if (scsi_device_get(sdev) == 0) {
  			/* The following ensures the attached sdev is
  			 * offline on return from ata_scsi_offline_dev()
  			 * regardless it wins or loses the race
  			 * against this function.
  			 */
  			scsi_device_set_state(sdev, SDEV_OFFLINE);
  		} else {
  			WARN_ON(1);
  			sdev = NULL;
  		}
  	}
  
  	spin_unlock_irqrestore(ap->lock, flags);
  	mutex_unlock(&ap->scsi_host->scan_mutex);
  
  	if (sdev) {
  		ata_dev_info(dev, "detaching (SCSI %s)\n",
  			     dev_name(&sdev->sdev_gendev));
  
  		scsi_remove_device(sdev);
  		scsi_device_put(sdev);
  	}
  }
  
  static void ata_scsi_handle_link_detach(struct ata_link *link)
  {
  	struct ata_port *ap = link->ap;
  	struct ata_device *dev;
  
  	ata_for_each_dev(dev, link, ALL) {
  		unsigned long flags;
  
  		if (!(dev->flags & ATA_DFLAG_DETACHED))
  			continue;
  
  		spin_lock_irqsave(ap->lock, flags);
  		dev->flags &= ~ATA_DFLAG_DETACHED;
  		spin_unlock_irqrestore(ap->lock, flags);
  
  		if (zpodd_dev_enabled(dev))
  			zpodd_exit(dev);
  
  		ata_scsi_remove_dev(dev);
  	}
  }
  
  /**
   *	ata_scsi_media_change_notify - send media change event
   *	@dev: Pointer to the disk device with media change event
   *
   *	Tell the block layer to send a media change notification
   *	event.
   *
   * 	LOCKING:
   * 	spin_lock_irqsave(host lock)
   */
  void ata_scsi_media_change_notify(struct ata_device *dev)
  {
  	if (dev->sdev)
  		sdev_evt_send_simple(dev->sdev, SDEV_EVT_MEDIA_CHANGE,
  				     GFP_ATOMIC);
  }
  
  /**
   *	ata_scsi_hotplug - SCSI part of hotplug
   *	@work: Pointer to ATA port to perform SCSI hotplug on
   *
   *	Perform SCSI part of hotplug.  It's executed from a separate
   *	workqueue after EH completes.  This is necessary because SCSI
   *	hot plugging requires working EH and hot unplugging is
   *	synchronized with hot plugging with a mutex.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep).
   */
  void ata_scsi_hotplug(struct work_struct *work)
  {
  	struct ata_port *ap =
  		container_of(work, struct ata_port, hotplug_task.work);
  	int i;
  
  	if (ap->pflags & ATA_PFLAG_UNLOADING) {
  		DPRINTK("ENTER/EXIT - unloading\n");
  		return;
  	}
  
  	/*
  	 * XXX - UGLY HACK
  	 *
  	 * The block layer suspend/resume path is fundamentally broken due
  	 * to freezable kthreads and workqueue and may deadlock if a block
  	 * device gets removed while resume is in progress.  I don't know
  	 * what the solution is short of removing freezable kthreads and
  	 * workqueues altogether.
  	 *
  	 * The following is an ugly hack to avoid kicking off device
  	 * removal while freezer is active.  This is a joke but does avoid
  	 * this particular deadlock scenario.
  	 *
  	 * https://bugzilla.kernel.org/show_bug.cgi?id=62801
  	 * http://marc.info/?l=linux-kernel&m=138695698516487
  	 */
  #ifdef CONFIG_FREEZER
  	while (pm_freezing)
  		msleep(10);
  #endif
  
  	DPRINTK("ENTER\n");
  	mutex_lock(&ap->scsi_scan_mutex);
  
  	/* Unplug detached devices.  We cannot use link iterator here
  	 * because PMP links have to be scanned even if PMP is
  	 * currently not attached.  Iterate manually.
  	 */
  	ata_scsi_handle_link_detach(&ap->link);
  	if (ap->pmp_link)
  		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
  			ata_scsi_handle_link_detach(&ap->pmp_link[i]);
  
  	/* scan for new ones */
  	ata_scsi_scan_host(ap, 0);
  
  	mutex_unlock(&ap->scsi_scan_mutex);
  	DPRINTK("EXIT\n");
  }
  
  /**
   *	ata_scsi_user_scan - indication for user-initiated bus scan
   *	@shost: SCSI host to scan
   *	@channel: Channel to scan
   *	@id: ID to scan
   *	@lun: LUN to scan
   *
   *	This function is called when user explicitly requests bus
   *	scan.  Set probe pending flag and invoke EH.
   *
   *	LOCKING:
   *	SCSI layer (we don't care)
   *
   *	RETURNS:
   *	Zero.
   */
  int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
  		       unsigned int id, u64 lun)
  {
  	struct ata_port *ap = ata_shost_to_port(shost);
  	unsigned long flags;
  	int devno, rc = 0;
  
  	if (!ap->ops->error_handler)
  		return -EOPNOTSUPP;
  
  	if (lun != SCAN_WILD_CARD && lun)
  		return -EINVAL;
  
  	if (!sata_pmp_attached(ap)) {
  		if (channel != SCAN_WILD_CARD && channel)
  			return -EINVAL;
  		devno = id;
  	} else {
  		if (id != SCAN_WILD_CARD && id)
  			return -EINVAL;
  		devno = channel;
  	}
  
  	spin_lock_irqsave(ap->lock, flags);
  
  	if (devno == SCAN_WILD_CARD) {
  		struct ata_link *link;
  
  		ata_for_each_link(link, ap, EDGE) {
  			struct ata_eh_info *ehi = &link->eh_info;
  			ehi->probe_mask |= ATA_ALL_DEVICES;
  			ehi->action |= ATA_EH_RESET;
  		}
  	} else {
  		struct ata_device *dev = ata_find_dev(ap, devno);
  
  		if (dev) {
  			struct ata_eh_info *ehi = &dev->link->eh_info;
  			ehi->probe_mask |= 1 << dev->devno;
  			ehi->action |= ATA_EH_RESET;
  		} else
  			rc = -EINVAL;
  	}
  
  	if (rc == 0) {
  		ata_port_schedule_eh(ap);
  		spin_unlock_irqrestore(ap->lock, flags);
  		ata_port_wait_eh(ap);
  	} else
  		spin_unlock_irqrestore(ap->lock, flags);
  
  	return rc;
  }
  
  /**
   *	ata_scsi_dev_rescan - initiate scsi_rescan_device()
   *	@work: Pointer to ATA port to perform scsi_rescan_device()
   *
   *	After ATA pass thru (SAT) commands are executed successfully,
   *	libata need to propagate the changes to SCSI layer.
   *
   *	LOCKING:
   *	Kernel thread context (may sleep).
   */
  void ata_scsi_dev_rescan(struct work_struct *work)
  {
  	struct ata_port *ap =
  		container_of(work, struct ata_port, scsi_rescan_task);
  	struct ata_link *link;
  	struct ata_device *dev;
  	unsigned long flags;
  
  	mutex_lock(&ap->scsi_scan_mutex);
  	spin_lock_irqsave(ap->lock, flags);
  
  	ata_for_each_link(link, ap, EDGE) {
  		ata_for_each_dev(dev, link, ENABLED) {
  			struct scsi_device *sdev = dev->sdev;
  
  			if (!sdev)
  				continue;
  			if (scsi_device_get(sdev))
  				continue;
  
  			spin_unlock_irqrestore(ap->lock, flags);
  			scsi_rescan_device(&(sdev->sdev_gendev));
  			scsi_device_put(sdev);
  			spin_lock_irqsave(ap->lock, flags);
  		}
  	}
  
  	spin_unlock_irqrestore(ap->lock, flags);
  	mutex_unlock(&ap->scsi_scan_mutex);
  }
  
  /**
   *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
   *	@host: ATA host container for all SAS ports
   *	@port_info: Information from low-level host driver
   *	@shost: SCSI host that the scsi device is attached to
   *
   *	LOCKING:
   *	PCI/etc. bus probe sem.
   *
   *	RETURNS:
   *	ata_port pointer on success / NULL on failure.
   */
  
  struct ata_port *ata_sas_port_alloc(struct ata_host *host,
  				    struct ata_port_info *port_info,
  				    struct Scsi_Host *shost)
  {
  	struct ata_port *ap;
  
  	ap = ata_port_alloc(host);
  	if (!ap)
  		return NULL;
  
  	ap->port_no = 0;
  	ap->lock = &host->lock;
  	ap->pio_mask = port_info->pio_mask;
  	ap->mwdma_mask = port_info->mwdma_mask;
  	ap->udma_mask = port_info->udma_mask;
  	ap->flags |= port_info->flags;
  	ap->ops = port_info->port_ops;
  	ap->cbl = ATA_CBL_SATA;
  
  	return ap;
  }
  EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
  
  /**
   *	ata_sas_port_start - Set port up for dma.
   *	@ap: Port to initialize
   *
   *	Called just after data structures for each port are
   *	initialized.
   *
   *	May be used as the port_start() entry in ata_port_operations.
   *
   *	LOCKING:
   *	Inherited from caller.
   */
  int ata_sas_port_start(struct ata_port *ap)
  {
  	/*
  	 * the port is marked as frozen at allocation time, but if we don't
  	 * have new eh, we won't thaw it
  	 */
  	if (!ap->ops->error_handler)
  		ap->pflags &= ~ATA_PFLAG_FROZEN;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(ata_sas_port_start);
  
  /**
   *	ata_port_stop - Undo ata_sas_port_start()
   *	@ap: Port to shut down
   *
   *	May be used as the port_stop() entry in ata_port_operations.
   *
   *	LOCKING:
   *	Inherited from caller.
   */
  
  void ata_sas_port_stop(struct ata_port *ap)
  {
  }
  EXPORT_SYMBOL_GPL(ata_sas_port_stop);
  
  /**
   * ata_sas_async_probe - simply schedule probing and return
   * @ap: Port to probe
   *
   * For batch scheduling of probe for sas attached ata devices, assumes
   * the port has already been through ata_sas_port_init()
   */
  void ata_sas_async_probe(struct ata_port *ap)
  {
  	__ata_port_probe(ap);
  }
  EXPORT_SYMBOL_GPL(ata_sas_async_probe);
  
  int ata_sas_sync_probe(struct ata_port *ap)
  {
  	return ata_port_probe(ap);
  }
  EXPORT_SYMBOL_GPL(ata_sas_sync_probe);
  
  
  /**
   *	ata_sas_port_init - Initialize a SATA device
   *	@ap: SATA port to initialize
   *
   *	LOCKING:
   *	PCI/etc. bus probe sem.
   *
   *	RETURNS:
   *	Zero on success, non-zero on error.
   */
  
  int ata_sas_port_init(struct ata_port *ap)
  {
  	int rc = ap->ops->port_start(ap);
  
  	if (rc)
  		return rc;
  	ap->print_id = atomic_inc_return(&ata_print_id);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(ata_sas_port_init);
  
  /**
   *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
   *	@ap: SATA port to destroy
   *
   */
  
  void ata_sas_port_destroy(struct ata_port *ap)
  {
  	if (ap->ops->port_stop)
  		ap->ops->port_stop(ap);
  	kfree(ap);
  }
  EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
  
  /**
   *	ata_sas_slave_configure - Default slave_config routine for libata devices
   *	@sdev: SCSI device to configure
   *	@ap: ATA port to which SCSI device is attached
   *
   *	RETURNS:
   *	Zero.
   */
  
  int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
  {
  	ata_scsi_sdev_config(sdev);
  	ata_scsi_dev_config(sdev, ap->link.device);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
  
  /**
   *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
   *	@cmd: SCSI command to be sent
   *	@ap:	ATA port to which the command is being sent
   *
   *	RETURNS:
   *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
   *	0 otherwise.
   */
  
  int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
  {
  	int rc = 0;
  
  	ata_scsi_dump_cdb(ap, cmd);
  
  	if (likely(ata_dev_enabled(ap->link.device)))
  		rc = __ata_scsi_queuecmd(cmd, ap->link.device);
  	else {
  		cmd->result = (DID_BAD_TARGET << 16);
  		cmd->scsi_done(cmd);
  	}
  	return rc;
  }
  EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
  
  int ata_sas_allocate_tag(struct ata_port *ap)
  {
  	unsigned int max_queue = ap->host->n_tags;
  	unsigned int i, tag;
  
  	for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) {
  		tag = tag < max_queue ? tag : 0;
  
  		/* the last tag is reserved for internal command. */
  		if (tag == ATA_TAG_INTERNAL)
  			continue;
  
  		if (!test_and_set_bit(tag, &ap->sas_tag_allocated)) {
  			ap->sas_last_tag = tag;
  			return tag;
  		}
  	}
  	return -1;
  }
  
  void ata_sas_free_tag(unsigned int tag, struct ata_port *ap)
  {
  	clear_bit(tag, &ap->sas_tag_allocated);
  }
  