// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  libata-scsi.c - helper library for ATA
 *
 *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
 *  Copyright 2003-2004 Jeff Garzik
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/driver-api/libata.rst
 *
 *  Hardware documentation available from
 *  - http://www.t10.org/
 *  - http://www.t13.org/
 */

#include <linux/compat.h>
#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 <linux/of.h>

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

#define ATA_SCSI_RBUF_SIZE      576

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);

#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 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 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);

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;

        scsi_build_sense(cmd, d_sense, 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);
}

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

/**
 *      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);
}
EXPORT_SYMBOL_GPL(ata_scsi_unlock_native_capacity);

/**
 *      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 sensebuf[SCSI_SENSE_BUFFERSIZE];
        u8 scsi_cmd[MAX_COMMAND_SIZE];
        u8 args[4], *argbuf = 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;

        memset(sensebuf, 0, sizeof(sensebuf));
        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] = ATA_SMART_LBAM_PASS;
                scsi_cmd[12] = ATA_SMART_LBAH_PASS;
        } 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 (cmd_result < 0) {
                rc = cmd_result;
                goto error;
        }
        if (scsi_sense_valid(&sshdr)) {/* sense data available */
                u8 *desc = sensebuf + 8;

                /* If we set cc then ATA pass-through will cause a
                 * check condition even if no error. Filter that. */
                if (scsi_status_is_check_condition(cmd_result)) {
                        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(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 sensebuf[SCSI_SENSE_BUFFERSIZE];
        u8 scsi_cmd[MAX_COMMAND_SIZE];
        u8 args[7];
        struct scsi_sense_hdr sshdr;
        int cmd_result;

        if (arg == NULL)
                return -EINVAL;

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

        memset(sensebuf, 0, sizeof(sensebuf));
        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 (cmd_result < 0) {
                rc = cmd_result;
                goto error;
        }
        if (scsi_sense_valid(&sshdr)) {/* sense data available */
                u8 *desc = sensebuf + 8;

                /* 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:
        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;
}

/*
 * This handles both native and compat commands, so anything added
 * here must have a compatible argument, or check in_compat_syscall()
 */
int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
                     unsigned 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);
#ifdef CONFIG_COMPAT
                if (in_compat_syscall())
                        return put_user(val, (compat_ulong_t __user *)arg);
#endif
                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, unsigned 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);

                if (cmd->request->rq_flags & RQF_QUIET)
                        qc->flags |= ATA_QCFLAG_QUIET;
        } else {
                cmd->result = (DID_OK << 16) | SAM_STAT_TASK_SET_FULL;
                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->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);

        /*
         * 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(cmd, 1, 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);

        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);
}

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;
}

/**
 *      ata_scsi_dma_need_drain - 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.
 */
bool ata_scsi_dma_need_drain(struct request *rq)
{
        return atapi_cmd_type(scsi_req(rq)->cmd[0]) == ATAPI_MISC;
}
EXPORT_SYMBOL_GPL(ata_scsi_dma_need_drain);

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) {
                sdev->sector_size = ATA_SECT_SIZE;

                /* set DMA padding */
                blk_queue_update_dma_pad(q, ATA_DMA_PAD_SZ - 1);

                /* make room for appending the drain */
                blk_queue_max_segments(q, queue_max_segments(q) - 1);

                sdev->dma_drain_len = ATAPI_MAX_DRAIN;
                sdev->dma_drain_buf = kmalloc(sdev->dma_drain_len, GFP_NOIO);
                if (!sdev->dma_drain_buf) {
                        ata_dev_err(dev, "drain buffer allocation failed\n");
                        return -ENOMEM;
                }
        } 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, depth);
                scsi_change_queue_depth(sdev, depth);
        }

        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;
}
EXPORT_SYMBOL_GPL(ata_scsi_slave_config);

/**
 *      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);
        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(sdev->dma_drain_buf);
}
EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);

/**
 *      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;
}

static bool ata_check_nblocks(struct scsi_cmnd *scmd, u32 n_blocks)
{
        struct request *rq = scmd->request;
        u32 req_blocks;

        if (!blk_rq_is_passthrough(rq))
                return true;

        req_blocks = blk_rq_bytes(rq) / scmd->device->sector_size;
        if (n_blocks > req_blocks)
                return false;

        return true;
}

/**
 *      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;
                if (!ata_check_nblocks(scmd, n_block))
                        goto invalid_fld;
                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;
                if (!ata_check_nblocks(scmd, n_block))
                        goto invalid_fld;
                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;
                if (!ata_check_nblocks(scmd, n_block))
                        goto invalid_fld;
                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->hw_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)
{
        static const u8 versions[] = {
                0x00,
                0x60,   /* SAM-3 (no version claimed) */

                0x03,
                0x20,   /* SBC-2 (no version claimed) */

                0x03,
                0x00    /* SPC-3 (no version claimed) */
        };
        static 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;
        static 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)
{
        static 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;