/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *                  Horst Hummel <Horst.Hummel@de.ibm.com>
 *                  Carsten Otte <Cotte@de.ibm.com>
 *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 1999, 2009
 * EMC Symmetrix ioctl Copyright EMC Corporation, 2008
 * Author.........: Nigel Hislop <hislop_nigel@emc.com>
 */

#define KMSG_COMPONENT "dasd-eckd"

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/hdreg.h>        /* HDIO_GETGEO                      */
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/compat.h>
#include <linux/init.h>
#include <linux/seq_file.h>

#include <asm/css_chars.h>
#include <asm/debug.h>
#include <asm/idals.h>
#include <asm/ebcdic.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include <asm/cio.h>
#include <asm/ccwdev.h>
#include <asm/itcw.h>
#include <asm/schid.h>
#include <asm/chpid.h>

#include "dasd_int.h"
#include "dasd_eckd.h"

#ifdef PRINTK_HEADER
#undef PRINTK_HEADER
#endif                          /* PRINTK_HEADER */
#define PRINTK_HEADER "dasd(eckd):"

#define ECKD_C0(i) (i->home_bytes)
#define ECKD_F(i) (i->formula)
#define ECKD_F1(i) (ECKD_F(i)==0x01?(i->factors.f_0x01.f1):\
                    (i->factors.f_0x02.f1))
#define ECKD_F2(i) (ECKD_F(i)==0x01?(i->factors.f_0x01.f2):\
                    (i->factors.f_0x02.f2))
#define ECKD_F3(i) (ECKD_F(i)==0x01?(i->factors.f_0x01.f3):\
                    (i->factors.f_0x02.f3))
#define ECKD_F4(i) (ECKD_F(i)==0x02?(i->factors.f_0x02.f4):0)
#define ECKD_F5(i) (ECKD_F(i)==0x02?(i->factors.f_0x02.f5):0)
#define ECKD_F6(i) (i->factor6)
#define ECKD_F7(i) (i->factor7)
#define ECKD_F8(i) (i->factor8)

/*
 * raw track access always map to 64k in memory
 * so it maps to 16 blocks of 4k per track
 */
#define DASD_RAW_BLOCK_PER_TRACK 16
#define DASD_RAW_BLOCKSIZE 4096
/* 64k are 128 x 512 byte sectors  */
#define DASD_RAW_SECTORS_PER_TRACK 128

MODULE_LICENSE("GPL");

static struct dasd_discipline dasd_eckd_discipline;

/* The ccw bus type uses this table to find devices that it sends to
 * dasd_eckd_probe */
static struct ccw_device_id dasd_eckd_ids[] = {
        { CCW_DEVICE_DEVTYPE (0x3990, 0, 0x3390, 0), .driver_info = 0x1},
        { CCW_DEVICE_DEVTYPE (0x2105, 0, 0x3390, 0), .driver_info = 0x2},
        { CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3380, 0), .driver_info = 0x3},
        { CCW_DEVICE_DEVTYPE (0x3990, 0, 0x3380, 0), .driver_info = 0x4},
        { CCW_DEVICE_DEVTYPE (0x2105, 0, 0x3380, 0), .driver_info = 0x5},
        { CCW_DEVICE_DEVTYPE (0x9343, 0, 0x9345, 0), .driver_info = 0x6},
        { CCW_DEVICE_DEVTYPE (0x2107, 0, 0x3390, 0), .driver_info = 0x7},
        { CCW_DEVICE_DEVTYPE (0x2107, 0, 0x3380, 0), .driver_info = 0x8},
        { CCW_DEVICE_DEVTYPE (0x1750, 0, 0x3390, 0), .driver_info = 0x9},
        { CCW_DEVICE_DEVTYPE (0x1750, 0, 0x3380, 0), .driver_info = 0xa},
        { /* end of list */ },
};

MODULE_DEVICE_TABLE(ccw, dasd_eckd_ids);

static struct ccw_driver dasd_eckd_driver; /* see below */

static void *rawpadpage;

#define INIT_CQR_OK 0
#define INIT_CQR_UNFORMATTED 1
#define INIT_CQR_ERROR 2

/* emergency request for reserve/release */
static struct {
        struct dasd_ccw_req cqr;
        struct ccw1 ccw;
        char data[32];
} *dasd_reserve_req;
static DEFINE_MUTEX(dasd_reserve_mutex);

/* definitions for the path verification worker */
struct path_verification_work_data {
        struct work_struct worker;
        struct dasd_device *device;
        struct dasd_ccw_req cqr;
        struct ccw1 ccw;
        __u8 rcd_buffer[DASD_ECKD_RCD_DATA_SIZE];
        int isglobal;
        __u8 tbvpm;
};
static struct path_verification_work_data *path_verification_worker;
static DEFINE_MUTEX(dasd_path_verification_mutex);

struct check_attention_work_data {
        struct work_struct worker;
        struct dasd_device *device;
        __u8 lpum;
};

static int prepare_itcw(struct itcw *, unsigned int, unsigned int, int,
                        struct dasd_device *, struct dasd_device *,
                        unsigned int, int, unsigned int, unsigned int,
                        unsigned int, unsigned int);

/* initial attempt at a probe function. this can be simplified once
 * the other detection code is gone */
static int
dasd_eckd_probe (struct ccw_device *cdev)
{
        int ret;

        /* set ECKD specific ccw-device options */
        ret = ccw_device_set_options(cdev, CCWDEV_ALLOW_FORCE |
                                     CCWDEV_DO_PATHGROUP | CCWDEV_DO_MULTIPATH);
        if (ret) {
                DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
                                "dasd_eckd_probe: could not set "
                                "ccw-device options");
                return ret;
        }
        ret = dasd_generic_probe(cdev, &dasd_eckd_discipline);
        return ret;
}

static int
dasd_eckd_set_online(struct ccw_device *cdev)
{
        return dasd_generic_set_online(cdev, &dasd_eckd_discipline);
}

static const int sizes_trk0[] = { 28, 148, 84 };
#define LABEL_SIZE 140

/* head and record addresses of count_area read in analysis ccw */
static const int count_area_head[] = { 0, 0, 0, 0, 2 };
static const int count_area_rec[] = { 1, 2, 3, 4, 1 };

static inline unsigned int
round_up_multiple(unsigned int no, unsigned int mult)
{
        int rem = no % mult;
        return (rem ? no - rem + mult : no);
}

static inline unsigned int
ceil_quot(unsigned int d1, unsigned int d2)
{
        return (d1 + (d2 - 1)) / d2;
}

static unsigned int
recs_per_track(struct dasd_eckd_characteristics * rdc,
               unsigned int kl, unsigned int dl)
{
        int dn, kn;

        switch (rdc->dev_type) {
        case 0x3380:
                if (kl)
                        return 1499 / (15 + 7 + ceil_quot(kl + 12, 32) +
                                       ceil_quot(dl + 12, 32));
                else
                        return 1499 / (15 + ceil_quot(dl + 12, 32));
        case 0x3390:
                dn = ceil_quot(dl + 6, 232) + 1;
                if (kl) {
                        kn = ceil_quot(kl + 6, 232) + 1;
                        return 1729 / (10 + 9 + ceil_quot(kl + 6 * kn, 34) +
                                       9 + ceil_quot(dl + 6 * dn, 34));
                } else
                        return 1729 / (10 + 9 + ceil_quot(dl + 6 * dn, 34));
        case 0x9345:
                dn = ceil_quot(dl + 6, 232) + 1;
                if (kl) {
                        kn = ceil_quot(kl + 6, 232) + 1;
                        return 1420 / (18 + 7 + ceil_quot(kl + 6 * kn, 34) +
                                       ceil_quot(dl + 6 * dn, 34));
                } else
                        return 1420 / (18 + 7 + ceil_quot(dl + 6 * dn, 34));
        }
        return 0;
}

static void set_ch_t(struct ch_t *geo, __u32 cyl, __u8 head)
{
        geo->cyl = (__u16) cyl;
        geo->head = cyl >> 16;
        geo->head <<= 4;
        geo->head |= head;
}

static int check_XRC(struct ccw1 *ccw, struct DE_eckd_data *data,
                     struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        int rc;

        if (!private->rdc_data.facilities.XRC_supported)
                return 0;

        /* switch on System Time Stamp - needed for XRC Support */
        data->ga_extended |= 0x08; /* switch on 'Time Stamp Valid'   */
        data->ga_extended |= 0x02; /* switch on 'Extended Parameter' */

        rc = get_phys_clock(&data->ep_sys_time);
        /* Ignore return code if sync clock is switched off. */
        if (rc == -EOPNOTSUPP || rc == -EACCES)
                rc = 0;

        if (ccw) {
                ccw->count = sizeof(struct DE_eckd_data);
                ccw->flags |= CCW_FLAG_SLI;
        }

        return rc;
}

static int
define_extent(struct ccw1 *ccw, struct DE_eckd_data *data, unsigned int trk,
              unsigned int totrk, int cmd, struct dasd_device *device,
              int blksize)
{
        struct dasd_eckd_private *private = device->private;
        u16 heads, beghead, endhead;
        u32 begcyl, endcyl;
        int rc = 0;

        if (ccw) {
                ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
                ccw->flags = 0;
                ccw->count = 16;
                ccw->cda = (__u32)__pa(data);
        }

        memset(data, 0, sizeof(struct DE_eckd_data));
        switch (cmd) {
        case DASD_ECKD_CCW_READ_HOME_ADDRESS:
        case DASD_ECKD_CCW_READ_RECORD_ZERO:
        case DASD_ECKD_CCW_READ:
        case DASD_ECKD_CCW_READ_MT:
        case DASD_ECKD_CCW_READ_CKD:
        case DASD_ECKD_CCW_READ_CKD_MT:
        case DASD_ECKD_CCW_READ_KD:
        case DASD_ECKD_CCW_READ_KD_MT:
                data->mask.perm = 0x1;
                data->attributes.operation = private->attrib.operation;
                break;
        case DASD_ECKD_CCW_READ_COUNT:
                data->mask.perm = 0x1;
                data->attributes.operation = DASD_BYPASS_CACHE;
                break;
        case DASD_ECKD_CCW_READ_TRACK:
        case DASD_ECKD_CCW_READ_TRACK_DATA:
                data->mask.perm = 0x1;
                data->attributes.operation = private->attrib.operation;
                data->blk_size = 0;
                break;
        case DASD_ECKD_CCW_WRITE:
        case DASD_ECKD_CCW_WRITE_MT:
        case DASD_ECKD_CCW_WRITE_KD:
        case DASD_ECKD_CCW_WRITE_KD_MT:
                data->mask.perm = 0x02;
                data->attributes.operation = private->attrib.operation;
                rc = check_XRC(ccw, data, device);
                break;
        case DASD_ECKD_CCW_WRITE_CKD:
        case DASD_ECKD_CCW_WRITE_CKD_MT:
                data->attributes.operation = DASD_BYPASS_CACHE;
                rc = check_XRC(ccw, data, device);
                break;
        case DASD_ECKD_CCW_ERASE:
        case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
        case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
                data->mask.perm = 0x3;
                data->mask.auth = 0x1;
                data->attributes.operation = DASD_BYPASS_CACHE;
                rc = check_XRC(ccw, data, device);
                break;
        case DASD_ECKD_CCW_WRITE_FULL_TRACK:
                data->mask.perm = 0x03;
                data->attributes.operation = private->attrib.operation;
                data->blk_size = 0;
                break;
        case DASD_ECKD_CCW_WRITE_TRACK_DATA:
                data->mask.perm = 0x02;
                data->attributes.operation = private->attrib.operation;
                data->blk_size = blksize;
                rc = check_XRC(ccw, data, device);
                break;
        default:
                dev_err(&device->cdev->dev,
                        "0x%x is not a known command\n", cmd);
                break;
        }

        data->attributes.mode = 0x3;    /* ECKD */

        if ((private->rdc_data.cu_type == 0x2105 ||
             private->rdc_data.cu_type == 0x2107 ||
             private->rdc_data.cu_type == 0x1750)
            && !(private->uses_cdl && trk < 2))
                data->ga_extended |= 0x40; /* Regular Data Format Mode */

        heads = private->rdc_data.trk_per_cyl;
        begcyl = trk / heads;
        beghead = trk % heads;
        endcyl = totrk / heads;
        endhead = totrk % heads;

        /* check for sequential prestage - enhance cylinder range */
        if (data->attributes.operation == DASD_SEQ_PRESTAGE ||
            data->attributes.operation == DASD_SEQ_ACCESS) {

                if (endcyl + private->attrib.nr_cyl < private->real_cyl)
                        endcyl += private->attrib.nr_cyl;
                else
                        endcyl = (private->real_cyl - 1);
        }

        set_ch_t(&data->beg_ext, begcyl, beghead);
        set_ch_t(&data->end_ext, endcyl, endhead);
        return rc;
}


static void locate_record_ext(struct ccw1 *ccw, struct LRE_eckd_data *data,
                              unsigned int trk, unsigned int rec_on_trk,
                              int count, int cmd, struct dasd_device *device,
                              unsigned int reclen, unsigned int tlf)
{
        struct dasd_eckd_private *private = device->private;
        int sector;
        int dn, d;

        if (ccw) {
                ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD_EXT;
                ccw->flags = 0;
                if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK)
                        ccw->count = 22;
                else
                        ccw->count = 20;
                ccw->cda = (__u32)__pa(data);
        }

        memset(data, 0, sizeof(*data));
        sector = 0;
        if (rec_on_trk) {
                switch (private->rdc_data.dev_type) {
                case 0x3390:
                        dn = ceil_quot(reclen + 6, 232);
                        d = 9 + ceil_quot(reclen + 6 * (dn + 1), 34);
                        sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
                        break;
                case 0x3380:
                        d = 7 + ceil_quot(reclen + 12, 32);
                        sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
                        break;
                }
        }
        data->sector = sector;
        /* note: meaning of count depends on the operation
         *       for record based I/O it's the number of records, but for
         *       track based I/O it's the number of tracks
         */
        data->count = count;
        switch (cmd) {
        case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
                data->operation.orientation = 0x3;
                data->operation.operation = 0x03;
                break;
        case DASD_ECKD_CCW_READ_HOME_ADDRESS:
                data->operation.orientation = 0x3;
                data->operation.operation = 0x16;
                break;
        case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
                data->operation.orientation = 0x1;
                data->operation.operation = 0x03;
                data->count++;
                break;
        case DASD_ECKD_CCW_READ_RECORD_ZERO:
                data->operation.orientation = 0x3;
                data->operation.operation = 0x16;
                data->count++;
                break;
        case DASD_ECKD_CCW_WRITE:
        case DASD_ECKD_CCW_WRITE_MT:
        case DASD_ECKD_CCW_WRITE_KD:
        case DASD_ECKD_CCW_WRITE_KD_MT:
                data->auxiliary.length_valid = 0x1;
                data->length = reclen;
                data->operation.operation = 0x01;
                break;
        case DASD_ECKD_CCW_WRITE_CKD:
        case DASD_ECKD_CCW_WRITE_CKD_MT:
                data->auxiliary.length_valid = 0x1;
                data->length = reclen;
                data->operation.operation = 0x03;
                break;
        case DASD_ECKD_CCW_WRITE_FULL_TRACK:
                data->operation.orientation = 0x0;
                data->operation.operation = 0x3F;
                data->extended_operation = 0x11;
                data->length = 0;
                data->extended_parameter_length = 0x02;
                if (data->count > 8) {
                        data->extended_parameter[0] = 0xFF;
                        data->extended_parameter[1] = 0xFF;
                        data->extended_parameter[1] <<= (16 - count);
                } else {
                        data->extended_parameter[0] = 0xFF;
                        data->extended_parameter[0] <<= (8 - count);
                        data->extended_parameter[1] = 0x00;
                }
                data->sector = 0xFF;
                break;
        case DASD_ECKD_CCW_WRITE_TRACK_DATA:
                data->auxiliary.length_valid = 0x1;
                data->length = reclen;  /* not tlf, as one might think */
                data->operation.operation = 0x3F;
                data->extended_operation = 0x23;
                break;
        case DASD_ECKD_CCW_READ:
        case DASD_ECKD_CCW_READ_MT:
        case DASD_ECKD_CCW_READ_KD:
        case DASD_ECKD_CCW_READ_KD_MT:
                data->auxiliary.length_valid = 0x1;
                data->length = reclen;
                data->operation.operation = 0x06;
                break;
        case DASD_ECKD_CCW_READ_CKD:
        case DASD_ECKD_CCW_READ_CKD_MT:
                data->auxiliary.length_valid = 0x1;
                data->length = reclen;
                data->operation.operation = 0x16;
                break;
        case DASD_ECKD_CCW_READ_COUNT:
                data->operation.operation = 0x06;
                break;
        case DASD_ECKD_CCW_READ_TRACK:
                data->operation.orientation = 0x1;
                data->operation.operation = 0x0C;
                data->extended_parameter_length = 0;
                data->sector = 0xFF;
                break;
        case DASD_ECKD_CCW_READ_TRACK_DATA:
                data->auxiliary.length_valid = 0x1;
                data->length = tlf;
                data->operation.operation = 0x0C;
                break;
        case DASD_ECKD_CCW_ERASE:
                data->length = reclen;
                data->auxiliary.length_valid = 0x1;
                data->operation.operation = 0x0b;
                break;
        default:
                DBF_DEV_EVENT(DBF_ERR, device,
                            "fill LRE unknown opcode 0x%x", cmd);
                BUG();
        }
        set_ch_t(&data->seek_addr,
                 trk / private->rdc_data.trk_per_cyl,
                 trk % private->rdc_data.trk_per_cyl);
        data->search_arg.cyl = data->seek_addr.cyl;
        data->search_arg.head = data->seek_addr.head;
        data->search_arg.record = rec_on_trk;
}

static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
                      unsigned int trk, unsigned int totrk, int cmd,
                      struct dasd_device *basedev, struct dasd_device *startdev,
                      unsigned int format, unsigned int rec_on_trk, int count,
                      unsigned int blksize, unsigned int tlf)
{
        struct dasd_eckd_private *basepriv, *startpriv;
        struct LRE_eckd_data *lredata;
        struct DE_eckd_data *dedata;
        int rc = 0;

        basepriv = basedev->private;
        startpriv = startdev->private;
        dedata = &pfxdata->define_extent;
        lredata = &pfxdata->locate_record;

        ccw->cmd_code = DASD_ECKD_CCW_PFX;
        ccw->flags = 0;
        if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK) {
                ccw->count = sizeof(*pfxdata) + 2;
                ccw->cda = (__u32) __pa(pfxdata);
                memset(pfxdata, 0, sizeof(*pfxdata) + 2);
        } else {
                ccw->count = sizeof(*pfxdata);
                ccw->cda = (__u32) __pa(pfxdata);
                memset(pfxdata, 0, sizeof(*pfxdata));
        }

        /* prefix data */
        if (format > 1) {
                DBF_DEV_EVENT(DBF_ERR, basedev,
                              "PFX LRE unknown format 0x%x", format);
                BUG();
                return -EINVAL;
        }
        pfxdata->format = format;
        pfxdata->base_address = basepriv->ned->unit_addr;
        pfxdata->base_lss = basepriv->ned->ID;
        pfxdata->validity.define_extent = 1;

        /* private uid is kept up to date, conf_data may be outdated */
        if (startpriv->uid.type != UA_BASE_DEVICE) {
                pfxdata->validity.verify_base = 1;
                if (startpriv->uid.type == UA_HYPER_PAV_ALIAS)
                        pfxdata->validity.hyper_pav = 1;
        }

        rc = define_extent(NULL, dedata, trk, totrk, cmd, basedev, blksize);

        /*
         * For some commands the System Time Stamp is set in the define extent
         * data when XRC is supported. The validity of the time stamp must be
         * reflected in the prefix data as well.
         */
        if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
                pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid'   */

        if (format == 1) {
                locate_record_ext(NULL, lredata, trk, rec_on_trk, count, cmd,
                                  basedev, blksize, tlf);
        }

        return rc;
}

static int prefix(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
                  unsigned int trk, unsigned int totrk, int cmd,
                  struct dasd_device *basedev, struct dasd_device *startdev)
{
        return prefix_LRE(ccw, pfxdata, trk, totrk, cmd, basedev, startdev,
                          0, 0, 0, 0, 0);
}

static void
locate_record(struct ccw1 *ccw, struct LO_eckd_data *data, unsigned int trk,
              unsigned int rec_on_trk, int no_rec, int cmd,
              struct dasd_device * device, int reclen)
{
        struct dasd_eckd_private *private = device->private;
        int sector;
        int dn, d;

        DBF_DEV_EVENT(DBF_INFO, device,
                  "Locate: trk %d, rec %d, no_rec %d, cmd %d, reclen %d",
                  trk, rec_on_trk, no_rec, cmd, reclen);

        ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD;
        ccw->flags = 0;
        ccw->count = 16;
        ccw->cda = (__u32) __pa(data);

        memset(data, 0, sizeof(struct LO_eckd_data));
        sector = 0;
        if (rec_on_trk) {
                switch (private->rdc_data.dev_type) {
                case 0x3390:
                        dn = ceil_quot(reclen + 6, 232);
                        d = 9 + ceil_quot(reclen + 6 * (dn + 1), 34);
                        sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
                        break;
                case 0x3380:
                        d = 7 + ceil_quot(reclen + 12, 32);
                        sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
                        break;
                }
        }
        data->sector = sector;
        data->count = no_rec;
        switch (cmd) {
        case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
                data->operation.orientation = 0x3;
                data->operation.operation = 0x03;
                break;
        case DASD_ECKD_CCW_READ_HOME_ADDRESS:
                data->operation.orientation = 0x3;
                data->operation.operation = 0x16;
                break;
        case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
                data->operation.orientation = 0x1;
                data->operation.operation = 0x03;
                data->count++;
                break;
        case DASD_ECKD_CCW_READ_RECORD_ZERO:
                data->operation.orientation = 0x3;
                data->operation.operation = 0x16;
                data->count++;
                break;
        case DASD_ECKD_CCW_WRITE:
        case DASD_ECKD_CCW_WRITE_MT:
        case DASD_ECKD_CCW_WRITE_KD:
        case DASD_ECKD_CCW_WRITE_KD_MT:
                data->auxiliary.last_bytes_used = 0x1;
                data->length = reclen;
                data->operation.operation = 0x01;
                break;
        case DASD_ECKD_CCW_WRITE_CKD:
        case DASD_ECKD_CCW_WRITE_CKD_MT:
                data->auxiliary.last_bytes_used = 0x1;
                data->length = reclen;
                data->operation.operation = 0x03;
                break;
        case DASD_ECKD_CCW_READ:
        case DASD_ECKD_CCW_READ_MT:
        case DASD_ECKD_CCW_READ_KD:
        case DASD_ECKD_CCW_READ_KD_MT:
                data->auxiliary.last_bytes_used = 0x1;
                data->length = reclen;
                data->operation.operation = 0x06;
                break;
        case DASD_ECKD_CCW_READ_CKD:
        case DASD_ECKD_CCW_READ_CKD_MT:
                data->auxiliary.last_bytes_used = 0x1;
                data->length = reclen;
                data->operation.operation = 0x16;
                break;
        case DASD_ECKD_CCW_READ_COUNT:
                data->operation.operation = 0x06;
                break;
        case DASD_ECKD_CCW_ERASE:
                data->length = reclen;
                data->auxiliary.last_bytes_used = 0x1;
                data->operation.operation = 0x0b;
                break;
        default:
                DBF_DEV_EVENT(DBF_ERR, device, "unknown locate record "
                              "opcode 0x%x", cmd);
        }
        set_ch_t(&data->seek_addr,
                 trk / private->rdc_data.trk_per_cyl,
                 trk % private->rdc_data.trk_per_cyl);
        data->search_arg.cyl = data->seek_addr.cyl;
        data->search_arg.head = data->seek_addr.head;
        data->search_arg.record = rec_on_trk;
}

/*
 * Returns 1 if the block is one of the special blocks that needs
 * to get read/written with the KD variant of the command.
 * That is DASD_ECKD_READ_KD_MT instead of DASD_ECKD_READ_MT and
 * DASD_ECKD_WRITE_KD_MT instead of DASD_ECKD_WRITE_MT.
 * Luckily the KD variants differ only by one bit (0x08) from the
 * normal variant. So don't wonder about code like:
 * if (dasd_eckd_cdl_special(blk_per_trk, recid))
 *         ccw->cmd_code |= 0x8;
 */
static inline int
dasd_eckd_cdl_special(int blk_per_trk, int recid)
{
        if (recid < 3)
                return 1;
        if (recid < blk_per_trk)
                return 0;
        if (recid < 2 * blk_per_trk)
                return 1;
        return 0;
}

/*
 * Returns the record size for the special blocks of the cdl format.
 * Only returns something useful if dasd_eckd_cdl_special is true
 * for the recid.
 */
static inline int
dasd_eckd_cdl_reclen(int recid)
{
        if (recid < 3)
                return sizes_trk0[recid];
        return LABEL_SIZE;
}
/* create unique id from private structure. */
static void create_uid(struct dasd_eckd_private *private)
{
        int count;
        struct dasd_uid *uid;

        uid = &private->uid;
        memset(uid, 0, sizeof(struct dasd_uid));
        memcpy(uid->vendor, private->ned->HDA_manufacturer,
               sizeof(uid->vendor) - 1);
        EBCASC(uid->vendor, sizeof(uid->vendor) - 1);
        memcpy(uid->serial, private->ned->HDA_location,
               sizeof(uid->serial) - 1);
        EBCASC(uid->serial, sizeof(uid->serial) - 1);
        uid->ssid = private->gneq->subsystemID;
        uid->real_unit_addr = private->ned->unit_addr;
        if (private->sneq) {
                uid->type = private->sneq->sua_flags;
                if (uid->type == UA_BASE_PAV_ALIAS)
                        uid->base_unit_addr = private->sneq->base_unit_addr;
        } else {
                uid->type = UA_BASE_DEVICE;
        }
        if (private->vdsneq) {
                for (count = 0; count < 16; count++) {
                        sprintf(uid->vduit+2*count, "%02x",
                                private->vdsneq->uit[count]);
                }
        }
}

/*
 * Generate device unique id that specifies the physical device.
 */
static int dasd_eckd_generate_uid(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        unsigned long flags;

        if (!private)
                return -ENODEV;
        if (!private->ned || !private->gneq)
                return -ENODEV;
        spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
        create_uid(private);
        spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
        return 0;
}

static int dasd_eckd_get_uid(struct dasd_device *device, struct dasd_uid *uid)
{
        struct dasd_eckd_private *private = device->private;
        unsigned long flags;

        if (private) {
                spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
                *uid = private->uid;
                spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
                return 0;
        }
        return -EINVAL;
}

/*
 * compare device UID with data of a given dasd_eckd_private structure
 * return 0 for match
 */
static int dasd_eckd_compare_path_uid(struct dasd_device *device,
                                      struct dasd_eckd_private *private)
{
        struct dasd_uid device_uid;

        create_uid(private);
        dasd_eckd_get_uid(device, &device_uid);

        return memcmp(&device_uid, &private->uid, sizeof(struct dasd_uid));
}

static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,
                                   struct dasd_ccw_req *cqr,
                                   __u8 *rcd_buffer,
                                   __u8 lpm)
{
        struct ccw1 *ccw;
        /*
         * buffer has to start with EBCDIC "V1.0" to show
         * support for virtual device SNEQ
         */
        rcd_buffer[0] = 0xE5;
        rcd_buffer[1] = 0xF1;
        rcd_buffer[2] = 0x4B;
        rcd_buffer[3] = 0xF0;

        ccw = cqr->cpaddr;
        ccw->cmd_code = DASD_ECKD_CCW_RCD;
        ccw->flags = 0;
        ccw->cda = (__u32)(addr_t)rcd_buffer;
        ccw->count = DASD_ECKD_RCD_DATA_SIZE;
        cqr->magic = DASD_ECKD_MAGIC;

        cqr->startdev = device;
        cqr->memdev = device;
        cqr->block = NULL;
        cqr->expires = 10*HZ;
        cqr->lpm = lpm;
        cqr->retries = 256;
        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
}

/*
 * Wakeup helper for read_conf
 * if the cqr is not done and needs some error recovery
 * the buffer has to be re-initialized with the EBCDIC "V1.0"
 * to show support for virtual device SNEQ
 */
static void read_conf_cb(struct dasd_ccw_req *cqr, void *data)
{
        struct ccw1 *ccw;
        __u8 *rcd_buffer;

        if (cqr->status !=  DASD_CQR_DONE) {
                ccw = cqr->cpaddr;
                rcd_buffer = (__u8 *)((addr_t) ccw->cda);
                memset(rcd_buffer, 0, sizeof(*rcd_buffer));

                rcd_buffer[0] = 0xE5;
                rcd_buffer[1] = 0xF1;
                rcd_buffer[2] = 0x4B;
                rcd_buffer[3] = 0xF0;
        }
        dasd_wakeup_cb(cqr, data);
}

static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
                                           struct dasd_ccw_req *cqr,
                                           __u8 *rcd_buffer,
                                           __u8 lpm)
{
        struct ciw *ciw;
        int rc;
        /*
         * sanity check: scan for RCD command in extended SenseID data
         * some devices do not support RCD
         */
        ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
        if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD)
                return -EOPNOTSUPP;

        dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buffer, lpm);
        clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
        set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
        cqr->retries = 5;
        cqr->callback = read_conf_cb;
        rc = dasd_sleep_on_immediatly(cqr);
        return rc;
}

static int dasd_eckd_read_conf_lpm(struct dasd_device *device,
                                   void **rcd_buffer,
                                   int *rcd_buffer_size, __u8 lpm)
{
        struct ciw *ciw;
        char *rcd_buf = NULL;
        int ret;
        struct dasd_ccw_req *cqr;

        /*
         * sanity check: scan for RCD command in extended SenseID data
         * some devices do not support RCD
         */
        ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
        if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD) {
                ret = -EOPNOTSUPP;
                goto out_error;
        }
        rcd_buf = kzalloc(DASD_ECKD_RCD_DATA_SIZE, GFP_KERNEL | GFP_DMA);
        if (!rcd_buf) {
                ret = -ENOMEM;
                goto out_error;
        }
        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* RCD */,
                                   0, /* use rcd_buf as data ara */
                                   device);
        if (IS_ERR(cqr)) {
                DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                              "Could not allocate RCD request");
                ret = -ENOMEM;
                goto out_error;
        }
        dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buf, lpm);
        cqr->callback = read_conf_cb;
        ret = dasd_sleep_on(cqr);
        /*
         * on success we update the user input parms
         */
        dasd_sfree_request(cqr, cqr->memdev);
        if (ret)
                goto out_error;

        *rcd_buffer_size = DASD_ECKD_RCD_DATA_SIZE;
        *rcd_buffer = rcd_buf;
        return 0;
out_error:
        kfree(rcd_buf);
        *rcd_buffer = NULL;
        *rcd_buffer_size = 0;
        return ret;
}

static int dasd_eckd_identify_conf_parts(struct dasd_eckd_private *private)
{

        struct dasd_sneq *sneq;
        int i, count;

        private->ned = NULL;
        private->sneq = NULL;
        private->vdsneq = NULL;
        private->gneq = NULL;
        count = private->conf_len / sizeof(struct dasd_sneq);
        sneq = (struct dasd_sneq *)private->conf_data;
        for (i = 0; i < count; ++i) {
                if (sneq->flags.identifier == 1 && sneq->format == 1)
                        private->sneq = sneq;
                else if (sneq->flags.identifier == 1 && sneq->format == 4)
                        private->vdsneq = (struct vd_sneq *)sneq;
                else if (sneq->flags.identifier == 2)
                        private->gneq = (struct dasd_gneq *)sneq;
                else if (sneq->flags.identifier == 3 && sneq->res1 == 1)
                        private->ned = (struct dasd_ned *)sneq;
                sneq++;
        }
        if (!private->ned || !private->gneq) {
                private->ned = NULL;
                private->sneq = NULL;
                private->vdsneq = NULL;
                private->gneq = NULL;
                return -EINVAL;
        }
        return 0;

};

static unsigned char dasd_eckd_path_access(void *conf_data, int conf_len)
{
        struct dasd_gneq *gneq;
        int i, count, found;

        count = conf_len / sizeof(*gneq);
        gneq = (struct dasd_gneq *)conf_data;
        found = 0;
        for (i = 0; i < count; ++i) {
                if (gneq->flags.identifier == 2) {
                        found = 1;
                        break;
                }
                gneq++;
        }
        if (found)
                return ((char *)gneq)[18] & 0x07;
        else
                return 0;
}

static void dasd_eckd_clear_conf_data(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        int i;

        private->conf_data = NULL;
        private->conf_len = 0;
        for (i = 0; i < 8; i++) {
                kfree(device->path[i].conf_data);
                device->path[i].conf_data = NULL;
                device->path[i].cssid = 0;
                device->path[i].ssid = 0;
                device->path[i].chpid = 0;
        }
}


static int dasd_eckd_read_conf(struct dasd_device *device)
{
        void *conf_data;
        int conf_len, conf_data_saved;
        int rc, path_err, pos;
        __u8 lpm, opm;
        struct dasd_eckd_private *private, path_private;
        struct dasd_uid *uid;
        char print_path_uid[60], print_device_uid[60];
        struct channel_path_desc *chp_desc;
        struct subchannel_id sch_id;

        private = device->private;
        opm = ccw_device_get_path_mask(device->cdev);
        ccw_device_get_schid(device->cdev, &sch_id);
        conf_data_saved = 0;
        path_err = 0;

        /* get configuration data per operational path */
        for (lpm = 0x80; lpm; lpm>>= 1) {
                if (!(lpm & opm))
                        continue;
                rc = dasd_eckd_read_conf_lpm(device, &conf_data,
                                             &conf_len, lpm);
                if (rc && rc != -EOPNOTSUPP) {  /* -EOPNOTSUPP is ok */
                        DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
                                        "Read configuration data returned "
                                        "error %d", rc);
                        return rc;
                }
                if (conf_data == NULL) {
                        DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                        "No configuration data "
                                        "retrieved");
                        /* no further analysis possible */
                        dasd_path_add_opm(device, opm);
                        continue;       /* no error */
                }
                /* save first valid configuration data */
                if (!conf_data_saved) {
                        /* initially clear previously stored conf_data */
                        dasd_eckd_clear_conf_data(device);
                        private->conf_data = conf_data;
                        private->conf_len = conf_len;
                        if (dasd_eckd_identify_conf_parts(private)) {
                                private->conf_data = NULL;
                                private->conf_len = 0;
                                kfree(conf_data);
                                continue;
                        }
                        pos = pathmask_to_pos(lpm);
                        /* store per path conf_data */
                        device->path[pos].conf_data = conf_data;
                        device->path[pos].cssid = sch_id.cssid;
                        device->path[pos].ssid = sch_id.ssid;
                        chp_desc = ccw_device_get_chp_desc(device->cdev, pos);
                        if (chp_desc)
                                device->path[pos].chpid = chp_desc->chpid;
                        kfree(chp_desc);
                        /*
                         * build device UID that other path data
                         * can be compared to it
                         */
                        dasd_eckd_generate_uid(device);
                        conf_data_saved++;
                } else {
                        path_private.conf_data = conf_data;
                        path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;
                        if (dasd_eckd_identify_conf_parts(
                                    &path_private)) {
                                path_private.conf_data = NULL;
                                path_private.conf_len = 0;
                                kfree(conf_data);
                                continue;
                        }
                        if (dasd_eckd_compare_path_uid(
                                    device, &path_private)) {
                                uid = &path_private.uid;
                                if (strlen(uid->vduit) > 0)
                                        snprintf(print_path_uid,
                                                 sizeof(print_path_uid),
                                                 "%s.%s.%04x.%02x.%s",
                                                 uid->vendor, uid->serial,
                                                 uid->ssid, uid->real_unit_addr,
                                                 uid->vduit);
                                else
                                        snprintf(print_path_uid,
                                                 sizeof(print_path_uid),
                                                 "%s.%s.%04x.%02x",
                                                 uid->vendor, uid->serial,
                                                 uid->ssid,
                                                 uid->real_unit_addr);
                                uid = &private->uid;
                                if (strlen(uid->vduit) > 0)
                                        snprintf(print_device_uid,
                                                 sizeof(print_device_uid),
                                                 "%s.%s.%04x.%02x.%s",
                                                 uid->vendor, uid->serial,
                                                 uid->ssid, uid->real_unit_addr,
                                                 uid->vduit);
                                else
                                        snprintf(print_device_uid,
                                                 sizeof(print_device_uid),
                                                 "%s.%s.%04x.%02x",
                                                 uid->vendor, uid->serial,
                                                 uid->ssid,
                                                 uid->real_unit_addr);
                                dev_err(&device->cdev->dev,
                                        "Not all channel paths lead to "
                                        "the same device, path %02X leads to "
                                        "device %s instead of %s\n", lpm,
                                        print_path_uid, print_device_uid);
                                path_err = -EINVAL;
                                dasd_path_add_cablepm(device, lpm);
                                continue;
                        }
                        pos = pathmask_to_pos(lpm);
                        /* store per path conf_data */
                        device->path[pos].conf_data = conf_data;
                        device->path[pos].cssid = sch_id.cssid;
                        device->path[pos].ssid = sch_id.ssid;
                        chp_desc = ccw_device_get_chp_desc(device->cdev, pos);
                        if (chp_desc)
                                device->path[pos].chpid = chp_desc->chpid;
                        kfree(chp_desc);
                        path_private.conf_data = NULL;
                        path_private.conf_len = 0;
                }
                switch (dasd_eckd_path_access(conf_data, conf_len)) {
                case 0x02:
                        dasd_path_add_nppm(device, lpm);
                        break;
                case 0x03:
                        dasd_path_add_ppm(device, lpm);
                        break;
                }
                if (!dasd_path_get_opm(device)) {
                        dasd_path_set_opm(device, lpm);
                        dasd_generic_path_operational(device);
                } else {
                        dasd_path_add_opm(device, lpm);
                }
        }

        return path_err;
}

static u32 get_fcx_max_data(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        int fcx_in_css, fcx_in_gneq, fcx_in_features;
        int tpm, mdc;

        if (dasd_nofcx)
                return 0;
        /* is transport mode supported? */
        fcx_in_css = css_general_characteristics.fcx;
        fcx_in_gneq = private->gneq->reserved2[7] & 0x04;
        fcx_in_features = private->features.feature[40] & 0x80;
        tpm = fcx_in_css && fcx_in_gneq && fcx_in_features;

        if (!tpm)
                return 0;

        mdc = ccw_device_get_mdc(device->cdev, 0);
        if (mdc < 0) {
                dev_warn(&device->cdev->dev, "Detecting the maximum supported data size for zHPF requests failed\n");
                return 0;
        } else {
                return (u32)mdc * FCX_MAX_DATA_FACTOR;
        }
}

static int verify_fcx_max_data(struct dasd_device *device, __u8 lpm)
{
        struct dasd_eckd_private *private = device->private;
        int mdc;
        u32 fcx_max_data;

        if (private->fcx_max_data) {
                mdc = ccw_device_get_mdc(device->cdev, lpm);
                if ((mdc < 0)) {
                        dev_warn(&device->cdev->dev,
                                 "Detecting the maximum data size for zHPF "
                                 "requests failed (rc=%d) for a new path %x\n",
                                 mdc, lpm);
                        return mdc;
                }
                fcx_max_data = (u32)mdc * FCX_MAX_DATA_FACTOR;
                if (fcx_max_data < private->fcx_max_data) {
                        dev_warn(&device->cdev->dev,
                                 "The maximum data size for zHPF requests %u "
                                 "on a new path %x is below the active maximum "
                                 "%u\n", fcx_max_data, lpm,
                                 private->fcx_max_data);
                        return -EACCES;
                }
        }
        return 0;
}

static int rebuild_device_uid(struct dasd_device *device,
                              struct path_verification_work_data *data)
{
        struct dasd_eckd_private *private = device->private;
        __u8 lpm, opm = dasd_path_get_opm(device);
        int rc = -ENODEV;

        for (lpm = 0x80; lpm; lpm >>= 1) {
                if (!(lpm & opm))
                        continue;
                memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
                memset(&data->cqr, 0, sizeof(data->cqr));
                data->cqr.cpaddr = &data->ccw;
                rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
                                                     data->rcd_buffer,
                                                     lpm);

                if (rc) {
                        if (rc == -EOPNOTSUPP) /* -EOPNOTSUPP is ok */
                                continue;
                        DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
                                        "Read configuration data "
                                        "returned error %d", rc);
                        break;
                }
                memcpy(private->conf_data, data->rcd_buffer,
                       DASD_ECKD_RCD_DATA_SIZE);
                if (dasd_eckd_identify_conf_parts(private)) {
                        rc = -ENODEV;
                } else /* first valid path is enough */
                        break;
        }

        if (!rc)
                rc = dasd_eckd_generate_uid(device);

        return rc;
}

static void do_path_verification_work(struct work_struct *work)
{
        struct path_verification_work_data *data;
        struct dasd_device *device;
        struct dasd_eckd_private path_private;
        struct dasd_uid *uid;
        __u8 path_rcd_buf[DASD_ECKD_RCD_DATA_SIZE];
        __u8 lpm, opm, npm, ppm, epm, hpfpm, cablepm;
        unsigned long flags;
        char print_uid[60];
        int rc;

        data = container_of(work, struct path_verification_work_data, worker);
        device = data->device;

        /* delay path verification until device was resumed */
        if (test_bit(DASD_FLAG_SUSPENDED, &device->flags)) {
                schedule_work(work);
                return;
        }
        /* check if path verification already running and delay if so */
        if (test_and_set_bit(DASD_FLAG_PATH_VERIFY, &device->flags)) {
                schedule_work(work);
                return;
        }
        opm = 0;
        npm = 0;
        ppm = 0;
        epm = 0;
        hpfpm = 0;
        cablepm = 0;

        for (lpm = 0x80; lpm; lpm >>= 1) {
                if (!(lpm & data->tbvpm))
                        continue;
                memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
                memset(&data->cqr, 0, sizeof(data->cqr));
                data->cqr.cpaddr = &data->ccw;
                rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
                                                     data->rcd_buffer,
                                                     lpm);
                if (!rc) {
                        switch (dasd_eckd_path_access(data->rcd_buffer,
                                                      DASD_ECKD_RCD_DATA_SIZE)
                                ) {
                        case 0x02:
                                npm |= lpm;
                                break;
                        case 0x03:
                                ppm |= lpm;
                                break;
                        }
                        opm |= lpm;
                } else if (rc == -EOPNOTSUPP) {
                        DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                        "path verification: No configuration "
                                        "data retrieved");
                        opm |= lpm;
                } else if (rc == -EAGAIN) {
                        DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                        "path verification: device is stopped,"
                                        " try again later");
                        epm |= lpm;
                } else {
                        dev_warn(&device->cdev->dev,
                                 "Reading device feature codes failed "
                                 "(rc=%d) for new path %x\n", rc, lpm);
                        continue;
                }
                if (verify_fcx_max_data(device, lpm)) {
                        opm &= ~lpm;
                        npm &= ~lpm;
                        ppm &= ~lpm;
                        hpfpm |= lpm;
                        continue;
                }

                /*
                 * save conf_data for comparison after
                 * rebuild_device_uid may have changed
                 * the original data
                 */
                memcpy(&path_rcd_buf, data->rcd_buffer,
                       DASD_ECKD_RCD_DATA_SIZE);
                path_private.conf_data = (void *) &path_rcd_buf;
                path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;
                if (dasd_eckd_identify_conf_parts(&path_private)) {
                        path_private.conf_data = NULL;
                        path_private.conf_len = 0;
                        continue;
                }

                /*
                 * compare path UID with device UID only if at least
                 * one valid path is left
                 * in other case the device UID may have changed and
                 * the first working path UID will be used as device UID
                 */
                if (dasd_path_get_opm(device) &&
                    dasd_eckd_compare_path_uid(device, &path_private)) {
                        /*
                         * the comparison was not successful
                         * rebuild the device UID with at least one
                         * known path in case a z/VM hyperswap command
                         * has changed the device
                         *
                         * after this compare again
                         *
                         * if either the rebuild or the recompare fails
                         * the path can not be used
                         */
                        if (rebuild_device_uid(device, data) ||
                            dasd_eckd_compare_path_uid(
                                    device, &path_private)) {
                                uid = &path_private.uid;
                                if (strlen(uid->vduit) > 0)
                                        snprintf(print_uid, sizeof(print_uid),
                                                 "%s.%s.%04x.%02x.%s",
                                                 uid->vendor, uid->serial,
                                                 uid->ssid, uid->real_unit_addr,
                                                 uid->vduit);
                                else
                                        snprintf(print_uid, sizeof(print_uid),
                                                 "%s.%s.%04x.%02x",
                                                 uid->vendor, uid->serial,
                                                 uid->ssid,
                                                 uid->real_unit_addr);
                                dev_err(&device->cdev->dev,
                                        "The newly added channel path %02X "
                                        "will not be used because it leads "
                                        "to a different device %s\n",
                                        lpm, print_uid);
                                opm &= ~lpm;
                                npm &= ~lpm;
                                ppm &= ~lpm;
                                cablepm |= lpm;
                                continue;
                        }
                }

                /*
                 * There is a small chance that a path is lost again between
                 * above path verification and the following modification of
                 * the device opm mask. We could avoid that race here by using
                 * yet another path mask, but we rather deal with this unlikely
                 * situation in dasd_start_IO.
                 */
                spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
                if (!dasd_path_get_opm(device) && opm) {
                        dasd_path_set_opm(device, opm);
                        dasd_generic_path_operational(device);
                } else {
                        dasd_path_add_opm(device, opm);
                }
                dasd_path_add_nppm(device, npm);
                dasd_path_add_ppm(device, ppm);
                dasd_path_add_tbvpm(device, epm);
                dasd_path_add_cablepm(device, cablepm);
                dasd_path_add_nohpfpm(device, hpfpm);
                spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
        }
        clear_bit(DASD_FLAG_PATH_VERIFY, &device->flags);
        dasd_put_device(device);
        if (data->isglobal)
                mutex_unlock(&dasd_path_verification_mutex);
        else
                kfree(data);
}

static int dasd_eckd_verify_path(struct dasd_device *device, __u8 lpm)
{
        struct path_verification_work_data *data;

        data = kmalloc(sizeof(*data), GFP_ATOMIC | GFP_DMA);
        if (!data) {
                if (mutex_trylock(&dasd_path_verification_mutex)) {
                        data = path_verification_worker;
                        data->isglobal = 1;
                } else
                        return -ENOMEM;
        } else {
                memset(data, 0, sizeof(*data));
                data->isglobal = 0;
        }
        INIT_WORK(&data->worker, do_path_verification_work);
        dasd_get_device(device);
        data->device = device;
        data->tbvpm = lpm;
        schedule_work(&data->worker);
        return 0;
}

static void dasd_eckd_reset_path(struct dasd_device *device, __u8 pm)
{
        struct dasd_eckd_private *private = device->private;
        unsigned long flags;

        if (!private->fcx_max_data)
                private->fcx_max_data = get_fcx_max_data(device);
        spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
        dasd_path_set_tbvpm(device, pm ? : dasd_path_get_notoperpm(device));
        dasd_schedule_device_bh(device);
        spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}

static int dasd_eckd_read_features(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        struct dasd_psf_prssd_data *prssdp;
        struct dasd_rssd_features *features;
        struct dasd_ccw_req *cqr;
        struct ccw1 *ccw;
        int rc;

        memset(&private->features, 0, sizeof(struct dasd_rssd_features));
        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
                                   (sizeof(struct dasd_psf_prssd_data) +
                                    sizeof(struct dasd_rssd_features)),
                                   device);
        if (IS_ERR(cqr)) {
                DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s", "Could not "
                                "allocate initialization request");
                return PTR_ERR(cqr);
        }
        cqr->startdev = device;
        cqr->memdev = device;
        cqr->block = NULL;
        cqr->retries = 256;
        cqr->expires = 10 * HZ;

        /* Prepare for Read Subsystem Data */
        prssdp = (struct dasd_psf_prssd_data *) cqr->data;
        memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
        prssdp->order = PSF_ORDER_PRSSD;
        prssdp->suborder = 0x41;        /* Read Feature Codes */
        /* all other bytes of prssdp must be zero */

        ccw = cqr->cpaddr;
        ccw->cmd_code = DASD_ECKD_CCW_PSF;
        ccw->count = sizeof(struct dasd_psf_prssd_data);
        ccw->flags |= CCW_FLAG_CC;
        ccw->cda = (__u32)(addr_t) prssdp;

        /* Read Subsystem Data - feature codes */
        features = (struct dasd_rssd_features *) (prssdp + 1);
        memset(features, 0, sizeof(struct dasd_rssd_features));

        ccw++;
        ccw->cmd_code = DASD_ECKD_CCW_RSSD;
        ccw->count = sizeof(struct dasd_rssd_features);
        ccw->cda = (__u32)(addr_t) features;

        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        rc = dasd_sleep_on(cqr);
        if (rc == 0) {
                prssdp = (struct dasd_psf_prssd_data *) cqr->data;
                features = (struct dasd_rssd_features *) (prssdp + 1);
                memcpy(&private->features, features,
                       sizeof(struct dasd_rssd_features));
        } else
                dev_warn(&device->cdev->dev, "Reading device feature codes"
                         " failed with rc=%d\n", rc);
        dasd_sfree_request(cqr, cqr->memdev);
        return rc;
}


/*
 * Build CP for Perform Subsystem Function - SSC.
 */
static struct dasd_ccw_req *dasd_eckd_build_psf_ssc(struct dasd_device *device,
                                                    int enable_pav)
{
        struct dasd_ccw_req *cqr;
        struct dasd_psf_ssc_data *psf_ssc_data;
        struct ccw1 *ccw;

        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ ,
                                  sizeof(struct dasd_psf_ssc_data),
                                  device);

        if (IS_ERR(cqr)) {
                DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                           "Could not allocate PSF-SSC request");
                return cqr;
        }
        psf_ssc_data = (struct dasd_psf_ssc_data *)cqr->data;
        psf_ssc_data->order = PSF_ORDER_SSC;
        psf_ssc_data->suborder = 0xc0;
        if (enable_pav) {
                psf_ssc_data->suborder |= 0x08;
                psf_ssc_data->reserved[0] = 0x88;
        }
        ccw = cqr->cpaddr;
        ccw->cmd_code = DASD_ECKD_CCW_PSF;
        ccw->cda = (__u32)(addr_t)psf_ssc_data;
        ccw->count = 66;

        cqr->startdev = device;
        cqr->memdev = device;
        cqr->block = NULL;
        cqr->retries = 256;
        cqr->expires = 10*HZ;
        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        return cqr;
}

/*
 * Perform Subsystem Function.
 * It is necessary to trigger CIO for channel revalidation since this
 * call might change behaviour of DASD devices.
 */
static int
dasd_eckd_psf_ssc(struct dasd_device *device, int enable_pav,
                  unsigned long flags)
{
        struct dasd_ccw_req *cqr;
        int rc;

        cqr = dasd_eckd_build_psf_ssc(device, enable_pav);
        if (IS_ERR(cqr))
                return PTR_ERR(cqr);

        /*
         * set flags e.g. turn on failfast, to prevent blocking
         * the calling function should handle failed requests
         */
        cqr->flags |= flags;

        rc = dasd_sleep_on(cqr);
        if (!rc)
                /* trigger CIO to reprobe devices */
                css_schedule_reprobe();
        else if (cqr->intrc == -EAGAIN)
                rc = -EAGAIN;

        dasd_sfree_request(cqr, cqr->memdev);
        return rc;
}

/*
 * Valide storage server of current device.
 */
static int dasd_eckd_validate_server(struct dasd_device *device,
                                     unsigned long flags)
{
        struct dasd_eckd_private *private = device->private;
        int enable_pav, rc;

        if (private->uid.type == UA_BASE_PAV_ALIAS ||
            private->uid.type == UA_HYPER_PAV_ALIAS)
                return 0;
        if (dasd_nopav || MACHINE_IS_VM)
                enable_pav = 0;
        else
                enable_pav = 1;
        rc = dasd_eckd_psf_ssc(device, enable_pav, flags);

        /* may be requested feature is not available on server,
         * therefore just report error and go ahead */
        DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "PSF-SSC for SSID %04x "
                        "returned rc=%d", private->uid.ssid, rc);
        return rc;
}

/*
 * worker to do a validate server in case of a lost pathgroup
 */
static void dasd_eckd_do_validate_server(struct work_struct *work)
{
        struct dasd_device *device = container_of(work, struct dasd_device,
                                                  kick_validate);
        unsigned long flags = 0;

        set_bit(DASD_CQR_FLAGS_FAILFAST, &flags);
        if (dasd_eckd_validate_server(device, flags)
            == -EAGAIN) {
                /* schedule worker again if failed */
                schedule_work(&device->kick_validate);
                return;
        }

        dasd_put_device(device);
}

static void dasd_eckd_kick_validate_server(struct dasd_device *device)
{
        dasd_get_device(device);
        /* exit if device not online or in offline processing */
        if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
           device->state < DASD_STATE_ONLINE) {
                dasd_put_device(device);
                return;
        }
        /* queue call to do_validate_server to the kernel event daemon. */
        if (!schedule_work(&device->kick_validate))
                dasd_put_device(device);
}

/*
 * Check device characteristics.
 * If the device is accessible using ECKD discipline, the device is enabled.
 */
static int
dasd_eckd_check_characteristics(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        struct dasd_block *block;
        struct dasd_uid temp_uid;
        int rc, i;
        int readonly;
        unsigned long value;

        /* setup work queue for validate server*/
        INIT_WORK(&device->kick_validate, dasd_eckd_do_validate_server);
        /* setup work queue for summary unit check */
        INIT_WORK(&device->suc_work, dasd_alias_handle_summary_unit_check);

        if (!ccw_device_is_pathgroup(device->cdev)) {
                dev_warn(&device->cdev->dev,
                         "A channel path group could not be established\n");
                return -EIO;
        }
        if (!ccw_device_is_multipath(device->cdev)) {
                dev_info(&device->cdev->dev,
                         "The DASD is not operating in multipath mode\n");
        }
        if (!private) {
                private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
                if (!private) {
                        dev_warn(&device->cdev->dev,
                                 "Allocating memory for private DASD data "
                                 "failed\n");
                        return -ENOMEM;
                }
                device->private = private;
        } else {
                memset(private, 0, sizeof(*private));
        }
        /* Invalidate status of initial analysis. */
        private->init_cqr_status = -1;
        /* Set default cache operations. */
        private->attrib.operation = DASD_NORMAL_CACHE;
        private->attrib.nr_cyl = 0;

        /* Read Configuration Data */
        rc = dasd_eckd_read_conf(device);
        if (rc)
                goto out_err1;

        /* set some default values */
        device->default_expires = DASD_EXPIRES;
        device->default_retries = DASD_RETRIES;
        device->path_thrhld = DASD_ECKD_PATH_THRHLD;
        device->path_interval = DASD_ECKD_PATH_INTERVAL;

        if (private->gneq) {
                value = 1;
                for (i = 0; i < private->gneq->timeout.value; i++)
                        value = 10 * value;
                value = value * private->gneq->timeout.number;
                /* do not accept useless values */
                if (value != 0 && value <= DASD_EXPIRES_MAX)
                        device->default_expires = value;
        }

        dasd_eckd_get_uid(device, &temp_uid);
        if (temp_uid.type == UA_BASE_DEVICE) {
                block = dasd_alloc_block();
                if (IS_ERR(block)) {
                        DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                        "could not allocate dasd "
                                        "block structure");
                        rc = PTR_ERR(block);
                        goto out_err1;
                }
                device->block = block;
                block->base = device;
        }

        /* register lcu with alias handling, enable PAV */
        rc = dasd_alias_make_device_known_to_lcu(device);
        if (rc)
                goto out_err2;

        dasd_eckd_validate_server(device, 0);

        /* device may report different configuration data after LCU setup */
        rc = dasd_eckd_read_conf(device);
        if (rc)
                goto out_err3;

        /* Read Feature Codes */
        dasd_eckd_read_features(device);

        /* Read Device Characteristics */
        rc = dasd_generic_read_dev_chars(device, DASD_ECKD_MAGIC,
                                         &private->rdc_data, 64);
        if (rc) {
                DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
                                "Read device characteristic failed, rc=%d", rc);
                goto out_err3;
        }

        if ((device->features & DASD_FEATURE_USERAW) &&
            !(private->rdc_data.facilities.RT_in_LR)) {
                dev_err(&device->cdev->dev, "The storage server does not "
                        "support raw-track access\n");
                rc = -EINVAL;
                goto out_err3;
        }

        /* find the valid cylinder size */
        if (private->rdc_data.no_cyl == LV_COMPAT_CYL &&
            private->rdc_data.long_no_cyl)
                private->real_cyl = private->rdc_data.long_no_cyl;
        else
                private->real_cyl = private->rdc_data.no_cyl;

        private->fcx_max_data = get_fcx_max_data(device);

        readonly = dasd_device_is_ro(device);
        if (readonly)
                set_bit(DASD_FLAG_DEVICE_RO, &device->flags);

        dev_info(&device->cdev->dev, "New DASD %04X/%02X (CU %04X/%02X) "
                 "with %d cylinders, %d heads, %d sectors%s\n",
                 private->rdc_data.dev_type,
                 private->rdc_data.dev_model,
                 private->rdc_data.cu_type,
                 private->rdc_data.cu_model.model,
                 private->real_cyl,
                 private->rdc_data.trk_per_cyl,
                 private->rdc_data.sec_per_trk,
                 readonly ? ", read-only device" : "");
        return 0;

out_err3:
        dasd_alias_disconnect_device_from_lcu(device);
out_err2:
        dasd_free_block(device->block);
        device->block = NULL;
out_err1:
        kfree(private->conf_data);
        kfree(device->private);
        device->private = NULL;
        return rc;
}

static void dasd_eckd_uncheck_device(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        int i;

        dasd_alias_disconnect_device_from_lcu(device);
        private->ned = NULL;
        private->sneq = NULL;
        private->vdsneq = NULL;
        private->gneq = NULL;
        private->conf_len = 0;
        for (i = 0; i < 8; i++) {
                kfree(device->path[i].conf_data);
                if ((__u8 *)device->path[i].conf_data ==
                    private->conf_data) {
                        private->conf_data = NULL;
                        private->conf_len = 0;
                }
                device->path[i].conf_data = NULL;
                device->path[i].cssid = 0;
                device->path[i].ssid = 0;
                device->path[i].chpid = 0;
        }
        kfree(private->conf_data);
        private->conf_data = NULL;
}

static struct dasd_ccw_req *
dasd_eckd_analysis_ccw(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        struct eckd_count *count_data;
        struct LO_eckd_data *LO_data;
        struct dasd_ccw_req *cqr;
        struct ccw1 *ccw;
        int cplength, datasize;
        int i;

        cplength = 8;
        datasize = sizeof(struct DE_eckd_data) + 2*sizeof(struct LO_eckd_data);
        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize, device);
        if (IS_ERR(cqr))
                return cqr;
        ccw = cqr->cpaddr;
        /* Define extent for the first 3 tracks. */
        define_extent(ccw++, cqr->data, 0, 2,
                      DASD_ECKD_CCW_READ_COUNT, device, 0);
        LO_data = cqr->data + sizeof(struct DE_eckd_data);
        /* Locate record for the first 4 records on track 0. */
        ccw[-1].flags |= CCW_FLAG_CC;
        locate_record(ccw++, LO_data++, 0, 0, 4,
                      DASD_ECKD_CCW_READ_COUNT, device, 0);

        count_data = private->count_area;
        for (i = 0; i < 4; i++) {
                ccw[-1].flags |= CCW_FLAG_CC;
                ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
                ccw->flags = 0;
                ccw->count = 8;
                ccw->cda = (__u32)(addr_t) count_data;
                ccw++;
                count_data++;
        }

        /* Locate record for the first record on track 2. */
        ccw[-1].flags |= CCW_FLAG_CC;
        locate_record(ccw++, LO_data++, 2, 0, 1,
                      DASD_ECKD_CCW_READ_COUNT, device, 0);
        /* Read count ccw. */
        ccw[-1].flags |= CCW_FLAG_CC;
        ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
        ccw->flags = 0;
        ccw->count = 8;
        ccw->cda = (__u32)(addr_t) count_data;

        cqr->block = NULL;
        cqr->startdev = device;
        cqr->memdev = device;
        cqr->retries = 255;
        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        return cqr;
}

/* differentiate between 'no record found' and any other error */
static int dasd_eckd_analysis_evaluation(struct dasd_ccw_req *init_cqr)
{
        char *sense;
        if (init_cqr->status == DASD_CQR_DONE)
                return INIT_CQR_OK;
        else if (init_cqr->status == DASD_CQR_NEED_ERP ||
                 init_cqr->status == DASD_CQR_FAILED) {
                sense = dasd_get_sense(&init_cqr->irb);
                if (sense && (sense[1] & SNS1_NO_REC_FOUND))
                        return INIT_CQR_UNFORMATTED;
                else
                        return INIT_CQR_ERROR;
        } else
                return INIT_CQR_ERROR;
}

/*
 * This is the callback function for the init_analysis cqr. It saves
 * the status of the initial analysis ccw before it frees it and kicks
 * the device to continue the startup sequence. This will call
 * dasd_eckd_do_analysis again (if the devices has not been marked
 * for deletion in the meantime).
 */
static void dasd_eckd_analysis_callback(struct dasd_ccw_req *init_cqr,
                                        void *data)
{
        struct dasd_device *device = init_cqr->startdev;
        struct dasd_eckd_private *private = device->private;

        private->init_cqr_status = dasd_eckd_analysis_evaluation(init_cqr);
        dasd_sfree_request(init_cqr, device);
        dasd_kick_device(device);
}

static int dasd_eckd_start_analysis(struct dasd_block *block)
{
        struct dasd_ccw_req *init_cqr;

        init_cqr = dasd_eckd_analysis_ccw(block->base);
        if (IS_ERR(init_cqr))
                return PTR_ERR(init_cqr);
        init_cqr->callback = dasd_eckd_analysis_callback;
        init_cqr->callback_data = NULL;
        init_cqr->expires = 5*HZ;
        /* first try without ERP, so we can later handle unformatted
         * devices as special case
         */
        clear_bit(DASD_CQR_FLAGS_USE_ERP, &init_cqr->flags);
        init_cqr->retries = 0;
        dasd_add_request_head(init_cqr);
        return -EAGAIN;
}

static int dasd_eckd_end_analysis(struct dasd_block *block)
{
        struct dasd_device *device = block->base;
        struct dasd_eckd_private *private = device->private;
        struct eckd_count *count_area;
        unsigned int sb, blk_per_trk;
        int status, i;
        struct dasd_ccw_req *init_cqr;

        status = private->init_cqr_status;
        private->init_cqr_status = -1;
        if (status == INIT_CQR_ERROR) {
                /* try again, this time with full ERP */
                init_cqr = dasd_eckd_analysis_ccw(device);
                dasd_sleep_on(init_cqr);
                status = dasd_eckd_analysis_evaluation(init_cqr);
                dasd_sfree_request(init_cqr, device);
        }

        if (device->features & DASD_FEATURE_USERAW) {
                block->bp_block = DASD_RAW_BLOCKSIZE;
                blk_per_trk = DASD_RAW_BLOCK_PER_TRACK;
                block->s2b_shift = 3;
                goto raw;
        }

        if (status == INIT_CQR_UNFORMATTED) {
                dev_warn(&device->cdev->dev, "The DASD is not formatted\n");
                return -EMEDIUMTYPE;
        } else if (status == INIT_CQR_ERROR) {
                dev_err(&device->cdev->dev,
                        "Detecting the DASD disk layout failed because "
                        "of an I/O error\n");
                return -EIO;
        }

        private->uses_cdl = 1;
        /* Check Track 0 for Compatible Disk Layout */
        count_area = NULL;
        for (i = 0; i < 3; i++) {
                if (private->count_area[i].kl != 4 ||
                    private->count_area[i].dl != dasd_eckd_cdl_reclen(i) - 4 ||
                    private->count_area[i].cyl != 0 ||
                    private->count_area[i].head != count_area_head[i] ||
                    private->count_area[i].record != count_area_rec[i]) {
                        private->uses_cdl = 0;
                        break;
                }
        }
        if (i == 3)
                count_area = &private->count_area[4];

        if (private->uses_cdl == 0) {
                for (i = 0; i < 5; i++) {
                        if ((private->count_area[i].kl != 0) ||
                            (private->count_area[i].dl !=
                             private->count_area[0].dl) ||
                            private->count_area[i].cyl !=  0 ||
                            private->count_area[i].head != count_area_head[i] ||
                            private->count_area[i].record != count_area_rec[i])
                                break;
                }
                if (i == 5)
                        count_area = &private->count_area[0];
        } else {
                if (private->count_area[3].record == 1)
                        dev_warn(&device->cdev->dev,
                                 "Track 0 has no records following the VTOC\n");
        }

        if (count_area != NULL && count_area->kl == 0) {
                /* we found notthing violating our disk layout */
                if (dasd_check_blocksize(count_area->dl) == 0)
                        block->bp_block = count_area->dl;
        }
        if (block->bp_block == 0) {
                dev_warn(&device->cdev->dev,
                         "The disk layout of the DASD is not supported\n");
                return -EMEDIUMTYPE;
        }
        block->s2b_shift = 0;   /* bits to shift 512 to get a block */
        for (sb = 512; sb < block->bp_block; sb = sb << 1)
                block->s2b_shift++;

        blk_per_trk = recs_per_track(&private->rdc_data, 0, block->bp_block);

raw:
        block->blocks = (private->real_cyl *
                          private->rdc_data.trk_per_cyl *

                          blk_per_trk);

        dev_info(&device->cdev->dev,
                 "DASD with %d KB/block, %d KB total size, %d KB/track, "
                 "%s\n", (block->bp_block >> 10),
                 ((private->real_cyl *
                   private->rdc_data.trk_per_cyl *
                   blk_per_trk * (block->bp_block >> 9)) >> 1),
                 ((blk_per_trk * block->bp_block) >> 10),
                 private->uses_cdl ?
                 "compatible disk layout" : "linux disk layout");

        return 0;
}

static int dasd_eckd_do_analysis(struct dasd_block *block)
{
        struct dasd_eckd_private *private = block->base->private;

        if (private->init_cqr_status < 0)
                return dasd_eckd_start_analysis(block);
        else
                return dasd_eckd_end_analysis(block);
}

static int dasd_eckd_basic_to_ready(struct dasd_device *device)
{
        return dasd_alias_add_device(device);
};

static int dasd_eckd_online_to_ready(struct dasd_device *device)
{
        cancel_work_sync(&device->reload_device);
        cancel_work_sync(&device->kick_validate);
        return 0;
};

static int dasd_eckd_basic_to_known(struct dasd_device *device)
{
        return dasd_alias_remove_device(device);
};

static int
dasd_eckd_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
{
        struct dasd_eckd_private *private = block->base->private;

        if (dasd_check_blocksize(block->bp_block) == 0) {
                geo->sectors = recs_per_track(&private->rdc_data,
                                              0, block->bp_block);
        }
        geo->cylinders = private->rdc_data.no_cyl;
        geo->heads = private->rdc_data.trk_per_cyl;
        return 0;
}

/*
 * Build the TCW request for the format check
 */
static struct dasd_ccw_req *
dasd_eckd_build_check_tcw(struct dasd_device *base, struct format_data_t *fdata,
                          int enable_pav, struct eckd_count *fmt_buffer,
                          int rpt)
{
        struct dasd_eckd_private *start_priv;
        struct dasd_device *startdev = NULL;
        struct tidaw *last_tidaw = NULL;
        struct dasd_ccw_req *cqr;
        struct itcw *itcw;
        int itcw_size;
        int count;
        int rc;
        int i;

        if (enable_pav)
                startdev = dasd_alias_get_start_dev(base);

        if (!startdev)
                startdev = base;

        start_priv = startdev->private;

        count = rpt * (fdata->stop_unit - fdata->start_unit + 1);

        /*
         * we're adding 'count' amount of tidaw to the itcw.
         * calculate the corresponding itcw_size
         */
        itcw_size = itcw_calc_size(0, count, 0);

        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev);
        if (IS_ERR(cqr))
                return cqr;

        start_priv->count++;

        itcw = itcw_init(cqr->data, itcw_size, ITCW_OP_READ, 0, count, 0);
        if (IS_ERR(itcw)) {
                rc = -EINVAL;
                goto out_err;
        }

        cqr->cpaddr = itcw_get_tcw(itcw);
        rc = prepare_itcw(itcw, fdata->start_unit, fdata->stop_unit,
                          DASD_ECKD_CCW_READ_COUNT_MT, base, startdev, 0, count,
                          sizeof(struct eckd_count),
                          count * sizeof(struct eckd_count), 0, rpt);
        if (rc)
                goto out_err;

        for (i = 0; i < count; i++) {
                last_tidaw = itcw_add_tidaw(itcw, 0, fmt_buffer++,
                                            sizeof(struct eckd_count));
                if (IS_ERR(last_tidaw)) {
                        rc = -EINVAL;
                        goto out_err;
                }
        }

        last_tidaw->flags |= TIDAW_FLAGS_LAST;
        itcw_finalize(itcw);

        cqr->cpmode = 1;
        cqr->startdev = startdev;
        cqr->memdev = startdev;
        cqr->basedev = base;
        cqr->retries = startdev->default_retries;
        cqr->expires = startdev->default_expires * HZ;
        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        /* Set flags to suppress output for expected errors */
        set_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
        set_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags);

        return cqr;

out_err:
        dasd_sfree_request(cqr, startdev);

        return ERR_PTR(rc);
}

/*
 * Build the CCW request for the format check
 */
static struct dasd_ccw_req *
dasd_eckd_build_check(struct dasd_device *base, struct format_data_t *fdata,
                      int enable_pav, struct eckd_count *fmt_buffer, int rpt)
{
        struct dasd_eckd_private *start_priv;
        struct dasd_eckd_private *base_priv;
        struct dasd_device *startdev = NULL;
        struct dasd_ccw_req *cqr;
        struct ccw1 *ccw;
        void *data;
        int cplength, datasize;
        int use_prefix;
        int count;
        int i;

        if (enable_pav)
                startdev = dasd_alias_get_start_dev(base);

        if (!startdev)
                startdev = base;

        start_priv = startdev->private;
        base_priv = base->private;

        count = rpt * (fdata->stop_unit - fdata->start_unit + 1);

        use_prefix = base_priv->features.feature[8] & 0x01;

        if (use_prefix) {
                cplength = 1;
                datasize = sizeof(struct PFX_eckd_data);
        } else {
                cplength = 2;
                datasize = sizeof(struct DE_eckd_data) +
                        sizeof(struct LO_eckd_data);
        }
        cplength += count;

        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
                                  startdev);
        if (IS_ERR(cqr))
                return cqr;

        start_priv->count++;
        data = cqr->data;
        ccw = cqr->cpaddr;

        if (use_prefix) {
                prefix_LRE(ccw++, data, fdata->start_unit, fdata->stop_unit,
                           DASD_ECKD_CCW_READ_COUNT, base, startdev, 1, 0,
                           count, 0, 0);
        } else {
                define_extent(ccw++, data, fdata->start_unit, fdata->stop_unit,
                              DASD_ECKD_CCW_READ_COUNT, startdev, 0);

                data += sizeof(struct DE_eckd_data);
                ccw[-1].flags |= CCW_FLAG_CC;

                locate_record(ccw++, data, fdata->start_unit, 0, count,
                              DASD_ECKD_CCW_READ_COUNT, base, 0);
        }

        for (i = 0; i < count; i++) {
                ccw[-1].flags |= CCW_FLAG_CC;
                ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
                ccw->flags = CCW_FLAG_SLI;
                ccw->count = 8;
                ccw->cda = (__u32)(addr_t) fmt_buffer;
                ccw++;
                fmt_buffer++;
        }

        cqr->startdev = startdev;
        cqr->memdev = startdev;
        cqr->basedev = base;
        cqr->retries = DASD_RETRIES;
        cqr->expires = startdev->default_expires * HZ;
        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        /* Set flags to suppress output for expected errors */
        set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);

        return cqr;
}

static struct dasd_ccw_req *
dasd_eckd_build_format(struct dasd_device *base,
                       struct format_data_t *fdata,
                       int enable_pav)
{
        struct dasd_eckd_private *base_priv;
        struct dasd_eckd_private *start_priv;
        struct dasd_device *startdev = NULL;
        struct dasd_ccw_req *fcp;
        struct eckd_count *ect;
        struct ch_t address;
        struct ccw1 *ccw;
        void *data;
        int rpt;
        int cplength, datasize;
        int i, j;
        int intensity = 0;
        int r0_perm;
        int nr_tracks;
        int use_prefix;

        if (enable_pav)
                startdev = dasd_alias_get_start_dev(base);

        if (!startdev)
                startdev = base;

        start_priv = startdev->private;
        base_priv = base->private;

        rpt = recs_per_track(&base_priv->rdc_data, 0, fdata->blksize);

        nr_tracks = fdata->stop_unit - fdata->start_unit + 1;

        /*
         * fdata->intensity is a bit string that tells us what to do:
         *   Bit 0: write record zero
         *   Bit 1: write home address, currently not supported
         *   Bit 2: invalidate tracks
         *   Bit 3: use OS/390 compatible disk layout (cdl)
         *   Bit 4: do not allow storage subsystem to modify record zero
         * Only some bit combinations do make sense.
         */
        if (fdata->intensity & 0x10) {
                r0_perm = 0;
                intensity = fdata->intensity & ~0x10;
        } else {
                r0_perm = 1;
                intensity = fdata->intensity;
        }

        use_prefix = base_priv->features.feature[8] & 0x01;

        switch (intensity) {
        case 0x00:      /* Normal format */
        case 0x08:      /* Normal format, use cdl. */
                cplength = 2 + (rpt*nr_tracks);
                if (use_prefix)
                        datasize = sizeof(struct PFX_eckd_data) +
                                sizeof(struct LO_eckd_data) +
                                rpt * nr_tracks * sizeof(struct eckd_count);
                else
                        datasize = sizeof(struct DE_eckd_data) +
                                sizeof(struct LO_eckd_data) +
                                rpt * nr_tracks * sizeof(struct eckd_count);
                break;
        case 0x01:      /* Write record zero and format track. */
        case 0x09:      /* Write record zero and format track, use cdl. */
                cplength = 2 + rpt * nr_tracks;
                if (use_prefix)
                        datasize = sizeof(struct PFX_eckd_data) +
                                sizeof(struct LO_eckd_data) +
                                sizeof(struct eckd_count) +
                                rpt * nr_tracks * sizeof(struct eckd_count);
                else
                        datasize = sizeof(struct DE_eckd_data) +
                                sizeof(struct LO_eckd_data) +
                                sizeof(struct eckd_count) +
                                rpt * nr_tracks * sizeof(struct eckd_count);
                break;
        case 0x04:      /* Invalidate track. */
        case 0x0c:      /* Invalidate track, use cdl. */
                cplength = 3;
                if (use_prefix)
                        datasize = sizeof(struct PFX_eckd_data) +
                                sizeof(struct LO_eckd_data) +
                                sizeof(struct eckd_count);
                else
                        datasize = sizeof(struct DE_eckd_data) +
                                sizeof(struct LO_eckd_data) +
                                sizeof(struct eckd_count);
                break;
        default:
                dev_warn(&startdev->cdev->dev,
                         "An I/O control call used incorrect flags 0x%x\n",
                         fdata->intensity);
                return ERR_PTR(-EINVAL);
        }
        /* Allocate the format ccw request. */
        fcp = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength,
                                   datasize, startdev);
        if (IS_ERR(fcp))
                return fcp;

        start_priv->count++;
        data = fcp->data;
        ccw = fcp->cpaddr;

        switch (intensity & ~0x08) {
        case 0x00: /* Normal format. */
                if (use_prefix) {
                        prefix(ccw++, (struct PFX_eckd_data *) data,
                               fdata->start_unit, fdata->stop_unit,
                               DASD_ECKD_CCW_WRITE_CKD, base, startdev);
                        /* grant subsystem permission to format R0 */
                        if (r0_perm)
                                ((struct PFX_eckd_data *)data)
                                        ->define_extent.ga_extended |= 0x04;
                        data += sizeof(struct PFX_eckd_data);
                } else {
                        define_extent(ccw++, (struct DE_eckd_data *) data,
                                      fdata->start_unit, fdata->stop_unit,
                                      DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
                        /* grant subsystem permission to format R0 */
                        if (r0_perm)
                                ((struct DE_eckd_data *) data)
                                        ->ga_extended |= 0x04;
                        data += sizeof(struct DE_eckd_data);
                }
                ccw[-1].flags |= CCW_FLAG_CC;
                locate_record(ccw++, (struct LO_eckd_data *) data,
                              fdata->start_unit, 0, rpt*nr_tracks,
                              DASD_ECKD_CCW_WRITE_CKD, base,
                              fdata->blksize);
                data += sizeof(struct LO_eckd_data);
                break;
        case 0x01: /* Write record zero + format track. */
                if (use_prefix) {
                        prefix(ccw++, (struct PFX_eckd_data *) data,
                               fdata->start_unit, fdata->stop_unit,
                               DASD_ECKD_CCW_WRITE_RECORD_ZERO,
                               base, startdev);
                        data += sizeof(struct PFX_eckd_data);
                } else {
                        define_extent(ccw++, (struct DE_eckd_data *) data,
                               fdata->start_unit, fdata->stop_unit,
                               DASD_ECKD_CCW_WRITE_RECORD_ZERO, startdev, 0);
                        data += sizeof(struct DE_eckd_data);
                }
                ccw[-1].flags |= CCW_FLAG_CC;
                locate_record(ccw++, (struct LO_eckd_data *) data,
                              fdata->start_unit, 0, rpt * nr_tracks + 1,
                              DASD_ECKD_CCW_WRITE_RECORD_ZERO, base,
                              base->block->bp_block);
                data += sizeof(struct LO_eckd_data);
                break;
        case 0x04: /* Invalidate track. */
                if (use_prefix) {
                        prefix(ccw++, (struct PFX_eckd_data *) data,
                               fdata->start_unit, fdata->stop_unit,
                               DASD_ECKD_CCW_WRITE_CKD, base, startdev);
                        data += sizeof(struct PFX_eckd_data);
                } else {
                        define_extent(ccw++, (struct DE_eckd_data *) data,
                               fdata->start_unit, fdata->stop_unit,
                               DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
                        data += sizeof(struct DE_eckd_data);
                }
                ccw[-1].flags |= CCW_FLAG_CC;
                locate_record(ccw++, (struct LO_eckd_data *) data,
                              fdata->start_unit, 0, 1,
                              DASD_ECKD_CCW_WRITE_CKD, base, 8);
                data += sizeof(struct LO_eckd_data);
                break;
        }

        for (j = 0; j < nr_tracks; j++) {
                /* calculate cylinder and head for the current track */
                set_ch_t(&address,
                         (fdata->start_unit + j) /
                         base_priv->rdc_data.trk_per_cyl,
                         (fdata->start_unit + j) %
                         base_priv->rdc_data.trk_per_cyl);
                if (intensity & 0x01) { /* write record zero */
                        ect = (struct eckd_count *) data;
                        data += sizeof(struct eckd_count);
                        ect->cyl = address.cyl;
                        ect->head = address.head;
                        ect->record = 0;
                        ect->kl = 0;
                        ect->dl = 8;
                        ccw[-1].flags |= CCW_FLAG_CC;
                        ccw->cmd_code = DASD_ECKD_CCW_WRITE_RECORD_ZERO;
                        ccw->flags = CCW_FLAG_SLI;
                        ccw->count = 8;
                        ccw->cda = (__u32)(addr_t) ect;
                        ccw++;
                }
                if ((intensity & ~0x08) & 0x04) {       /* erase track */
                        ect = (struct eckd_count *) data;
                        data += sizeof(struct eckd_count);
                        ect->cyl = address.cyl;
                        ect->head = address.head;
                        ect->record = 1;
                        ect->kl = 0;
                        ect->dl = 0;
                        ccw[-1].flags |= CCW_FLAG_CC;
                        ccw->cmd_code = DASD_ECKD_CCW_WRITE_CKD;
                        ccw->flags = CCW_FLAG_SLI;
                        ccw->count = 8;
                        ccw->cda = (__u32)(addr_t) ect;
                } else {                /* write remaining records */
                        for (i = 0; i < rpt; i++) {
                                ect = (struct eckd_count *) data;
                                data += sizeof(struct eckd_count);
                                ect->cyl = address.cyl;
                                ect->head = address.head;
                                ect->record = i + 1;
                                ect->kl = 0;
                                ect->dl = fdata->blksize;
                                /*
                                 * Check for special tracks 0-1
                                 * when formatting CDL
                                 */
                                if ((intensity & 0x08) &&
                                    address.cyl == 0 && address.head == 0) {
                                        if (i < 3) {
                                                ect->kl = 4;
                                                ect->dl = sizes_trk0[i] - 4;
                                        }
                                }
                                if ((intensity & 0x08) &&
                                    address.cyl == 0 && address.head == 1) {
                                        ect->kl = 44;
                                        ect->dl = LABEL_SIZE - 44;
                                }
                                ccw[-1].flags |= CCW_FLAG_CC;
                                if (i != 0 || j == 0)
                                        ccw->cmd_code =
                                                DASD_ECKD_CCW_WRITE_CKD;
                                else
                                        ccw->cmd_code =
                                                DASD_ECKD_CCW_WRITE_CKD_MT;
                                ccw->flags = CCW_FLAG_SLI;
                                ccw->count = 8;
                                ccw->cda = (__u32)(addr_t) ect;
                                ccw++;
                        }
                }
        }

        fcp->startdev = startdev;
        fcp->memdev = startdev;
        fcp->basedev = base;
        fcp->retries = 256;
        fcp->expires = startdev->default_expires * HZ;
        fcp->buildclk = get_tod_clock();
        fcp->status = DASD_CQR_FILLED;

        return fcp;
}

/*
 * Wrapper function to build a CCW request depending on input data
 */
static struct dasd_ccw_req *
dasd_eckd_format_build_ccw_req(struct dasd_device *base,
                               struct format_data_t *fdata, int enable_pav,
                               int tpm, struct eckd_count *fmt_buffer, int rpt)
{
        struct dasd_ccw_req *ccw_req;

        if (!fmt_buffer) {
                ccw_req = dasd_eckd_build_format(base, fdata, enable_pav);
        } else {
                if (tpm)
                        ccw_req = dasd_eckd_build_check_tcw(base, fdata,
                                                            enable_pav,
                                                            fmt_buffer, rpt);
                else
                        ccw_req = dasd_eckd_build_check(base, fdata, enable_pav,
                                                        fmt_buffer, rpt);
        }

        return ccw_req;
}

/*
 * Sanity checks on format_data
 */
static int dasd_eckd_format_sanity_checks(struct dasd_device *base,
                                          struct format_data_t *fdata)
{
        struct dasd_eckd_private *private = base->private;

        if (fdata->start_unit >=
            (private->real_cyl * private->rdc_data.trk_per_cyl)) {
                dev_warn(&base->cdev->dev,
                         "Start track number %u used in formatting is too big\n",
                         fdata->start_unit);
                return -EINVAL;
        }
        if (fdata->stop_unit >=
            (private->real_cyl * private->rdc_data.trk_per_cyl)) {
                dev_warn(&base->cdev->dev,
                         "Stop track number %u used in formatting is too big\n",
                         fdata->stop_unit);
                return -EINVAL;
        }
        if (fdata->start_unit > fdata->stop_unit) {
                dev_warn(&base->cdev->dev,
                         "Start track %u used in formatting exceeds end track\n",
                         fdata->start_unit);
                return -EINVAL;
        }
        if (dasd_check_blocksize(fdata->blksize) != 0) {
                dev_warn(&base->cdev->dev,
                         "The DASD cannot be formatted with block size %u\n",
                         fdata->blksize);
                return -EINVAL;
        }
        return 0;
}

/*
 * This function will process format_data originally coming from an IOCTL
 */
static int dasd_eckd_format_process_data(struct dasd_device *base,
                                         struct format_data_t *fdata,
                                         int enable_pav, int tpm,
                                         struct eckd_count *fmt_buffer, int rpt,
                                         struct irb *irb)
{
        struct dasd_eckd_private *private = base->private;
        struct dasd_ccw_req *cqr, *n;
        struct list_head format_queue;
        struct dasd_device *device;
        char *sense = NULL;
        int old_start, old_stop, format_step;
        int step, retry;
        int rc;

        rc = dasd_eckd_format_sanity_checks(base, fdata);
        if (rc)
                return rc;

        INIT_LIST_HEAD(&format_queue);

        old_start = fdata->start_unit;
        old_stop = fdata->stop_unit;

        if (!tpm && fmt_buffer != NULL) {
                /* Command Mode / Format Check */
                format_step = 1;
        } else if (tpm && fmt_buffer != NULL) {
                /* Transport Mode / Format Check */
                format_step = DASD_CQR_MAX_CCW / rpt;
        } else {
                /* Normal Formatting */
                format_step = DASD_CQR_MAX_CCW /
                        recs_per_track(&private->rdc_data, 0, fdata->blksize);
        }

        do {
                retry = 0;
                while (fdata->start_unit <= old_stop) {
                        step = fdata->stop_unit - fdata->start_unit + 1;
                        if (step > format_step) {
                                fdata->stop_unit =
                                        fdata->start_unit + format_step - 1;
                        }

                        cqr = dasd_eckd_format_build_ccw_req(base, fdata,
                                                             enable_pav, tpm,
                                                             fmt_buffer, rpt);
                        if (IS_ERR(cqr)) {
                                rc = PTR_ERR(cqr);
                                if (rc == -ENOMEM) {
                                        if (list_empty(&format_queue))
                                                goto out;
                                        /*
                                         * not enough memory available, start
                                         * requests retry after first requests
                                         * were finished
                                         */
                                        retry = 1;
                                        break;
                                }
                                goto out_err;
                        }
                        list_add_tail(&cqr->blocklist, &format_queue);

                        if (fmt_buffer) {
                                step = fdata->stop_unit - fdata->start_unit + 1;
                                fmt_buffer += rpt * step;
                        }
                        fdata->start_unit = fdata->stop_unit + 1;
                        fdata->stop_unit = old_stop;
                }

                rc = dasd_sleep_on_queue(&format_queue);

out_err:
                list_for_each_entry_safe(cqr, n, &format_queue, blocklist) {
                        device = cqr->startdev;
                        private = device->private;

                        if (cqr->status == DASD_CQR_FAILED) {
                                /*
                                 * Only get sense data if called by format
                                 * check
                                 */
                                if (fmt_buffer && irb) {
                                        sense = dasd_get_sense(&cqr->irb);
                                        memcpy(irb, &cqr->irb, sizeof(*irb));
                                }
                                rc = -EIO;
                        }
                        list_del_init(&cqr->blocklist);
                        dasd_sfree_request(cqr, device);
                        private->count--;
                }

                if (rc && rc != -EIO)
                        goto out;
                if (rc == -EIO) {
                        /*
                         * In case fewer than the expected records are on the
                         * track, we will most likely get a 'No Record Found'
                         * error (in command mode) or a 'File Protected' error
                         * (in transport mode). Those particular cases shouldn't
                         * pass the -EIO to the IOCTL, therefore reset the rc
                         * and continue.
                         */
                        if (sense &&
                            (sense[1] & SNS1_NO_REC_FOUND ||
                             sense[1] & SNS1_FILE_PROTECTED))
                                retry = 1;
                        else
                                goto out;
                }

        } while (retry);

out:
        fdata->start_unit = old_start;
        fdata->stop_unit = old_stop;

        return rc;
}

static int dasd_eckd_format_device(struct dasd_device *base,
                                   struct format_data_t *fdata, int enable_pav)
{
        return dasd_eckd_format_process_data(base, fdata, enable_pav, 0, NULL,
                                             0, NULL);
}

/*
 * Helper function to count consecutive records of a single track.
 */
static int dasd_eckd_count_records(struct eckd_count *fmt_buffer, int start,
                                   int max)
{
        int head;
        int i;

        head = fmt_buffer[start].head;

        /*
         * There are 3 conditions where we stop counting:
         * - if data reoccurs (same head and record may reoccur), which may
         *   happen due to the way DASD_ECKD_CCW_READ_COUNT works
         * - when the head changes, because we're iterating over several tracks
         *   then (DASD_ECKD_CCW_READ_COUNT_MT)
         * - when we've reached the end of sensible data in the buffer (the
         *   record will be 0 then)
         */
        for (i = start; i < max; i++) {
                if (i > start) {
                        if ((fmt_buffer[i].head == head &&
                            fmt_buffer[i].record == 1) ||
                            fmt_buffer[i].head != head ||
                            fmt_buffer[i].record == 0)
                                break;
                }
        }

        return i - start;
}

/*
 * Evaluate a given range of tracks. Data like number of records, blocksize,
 * record ids, and key length are compared with expected data.
 *
 * If a mismatch occurs, the corresponding error bit is set, as well as
 * additional information, depending on the error.
 */
static void dasd_eckd_format_evaluate_tracks(struct eckd_count *fmt_buffer,
                                             struct format_check_t *cdata,
                                             int rpt_max, int rpt_exp,
                                             int trk_per_cyl, int tpm)
{
        struct ch_t geo;
        int max_entries;
        int count = 0;
        int trkcount;
        int blksize;
        int pos = 0;
        int i, j;
        int kl;

        trkcount = cdata->expect.stop_unit - cdata->expect.start_unit + 1;
        max_entries = trkcount * rpt_max;

        for (i = cdata->expect.start_unit; i <= cdata->expect.stop_unit; i++) {
                /* Calculate the correct next starting position in the buffer */
                if (tpm) {
                        while (fmt_buffer[pos].record == 0 &&
                               fmt_buffer[pos].dl == 0) {
                                if (pos++ > max_entries)
                                        break;
                        }
                } else {
                        if (i != cdata->expect.start_unit)
                                pos += rpt_max - count;
                }

                /* Calculate the expected geo values for the current track */
                set_ch_t(&geo, i / trk_per_cyl, i % trk_per_cyl);

                /* Count and check number of records */
                count = dasd_eckd_count_records(fmt_buffer, pos, pos + rpt_max);

                if (count < rpt_exp) {
                        cdata->result = DASD_FMT_ERR_TOO_FEW_RECORDS;
                        break;
                }
                if (count > rpt_exp) {
                        cdata->result = DASD_FMT_ERR_TOO_MANY_RECORDS;
                        break;
                }

                for (j = 0; j < count; j++, pos++) {
                        blksize = cdata->expect.blksize;
                        kl = 0;

                        /*
                         * Set special values when checking CDL formatted
                         * devices.
                         */
                        if ((cdata->expect.intensity & 0x08) &&
                            geo.cyl == 0 && geo.head == 0) {
                                if (j < 3) {
                                        blksize = sizes_trk0[j] - 4;
                                        kl = 4;
                                }
                        }
                        if ((cdata->expect.intensity & 0x08) &&
                            geo.cyl == 0 && geo.head == 1) {
                                blksize = LABEL_SIZE - 44;
                                kl = 44;
                        }

                        /* Check blocksize */
                        if (fmt_buffer[pos].dl != blksize) {
                                cdata->result = DASD_FMT_ERR_BLKSIZE;
                                goto out;
                        }
                        /* Check if key length is 0 */
                        if (fmt_buffer[pos].kl != kl) {
                                cdata->result = DASD_FMT_ERR_KEY_LENGTH;
                                goto out;
                        }
                        /* Check if record_id is correct */
                        if (fmt_buffer[pos].cyl != geo.cyl ||
                            fmt_buffer[pos].head != geo.head ||
                            fmt_buffer[pos].record != (j + 1)) {
                                cdata->result = DASD_FMT_ERR_RECORD_ID;
                                goto out;
                        }
                }
        }

out:
        /*
         * In case of no errors, we need to decrease by one
         * to get the correct positions.
         */
        if (!cdata->result) {
                i--;
                pos--;
        }

        cdata->unit = i;
        cdata->num_records = count;
        cdata->rec = fmt_buffer[pos].record;
        cdata->blksize = fmt_buffer[pos].dl;
        cdata->key_length = fmt_buffer[pos].kl;
}

/*
 * Check the format of a range of tracks of a DASD.
 */
static int dasd_eckd_check_device_format(struct dasd_device *base,
                                         struct format_check_t *cdata,
                                         int enable_pav)
{
        struct dasd_eckd_private *private = base->private;
        struct eckd_count *fmt_buffer;
        struct irb irb;
        int rpt_max, rpt_exp;
        int fmt_buffer_size;
        int trk_per_cyl;
        int trkcount;
        int tpm = 0;
        int rc;

        trk_per_cyl = private->rdc_data.trk_per_cyl;

        /* Get maximum and expected amount of records per track */
        rpt_max = recs_per_track(&private->rdc_data, 0, 512) + 1;
        rpt_exp = recs_per_track(&private->rdc_data, 0, cdata->expect.blksize);

        trkcount = cdata->expect.stop_unit - cdata->expect.start_unit + 1;
        fmt_buffer_size = trkcount * rpt_max * sizeof(struct eckd_count);

        fmt_buffer = kzalloc(fmt_buffer_size, GFP_KERNEL | GFP_DMA);
        if (!fmt_buffer)
                return -ENOMEM;

        /*
         * A certain FICON feature subset is needed to operate in transport
         * mode. Additionally, the support for transport mode is implicitly
         * checked by comparing the buffer size with fcx_max_data. As long as
         * the buffer size is smaller we can operate in transport mode and
         * process multiple tracks. If not, only one track at once is being
         * processed using command mode.
         */
        if ((private->features.feature[40] & 0x04) &&
            fmt_buffer_size <= private->fcx_max_data)
                tpm = 1;

        rc = dasd_eckd_format_process_data(base, &cdata->expect, enable_pav,
                                           tpm, fmt_buffer, rpt_max, &irb);
        if (rc && rc != -EIO)
                goto out;
        if (rc == -EIO) {
                /*
                 * If our first attempt with transport mode enabled comes back
                 * with an incorrect length error, we're going to retry the
                 * check with command mode.
                 */
                if (tpm && scsw_cstat(&irb.scsw) == 0x40) {
                        tpm = 0;
                        rc = dasd_eckd_format_process_data(base, &cdata->expect,
                                                           enable_pav, tpm,
                                                           fmt_buffer, rpt_max,
                                                           &irb);
                        if (rc)
                                goto out;
                } else {
                        goto out;
                }
        }

        dasd_eckd_format_evaluate_tracks(fmt_buffer, cdata, rpt_max, rpt_exp,
                                         trk_per_cyl, tpm);

out:
        kfree(fmt_buffer);

        return rc;
}

static void dasd_eckd_handle_terminated_request(struct dasd_ccw_req *cqr)
{
        if (cqr->retries < 0) {
                cqr->status = DASD_CQR_FAILED;
                return;
        }
        cqr->status = DASD_CQR_FILLED;
        if (cqr->block && (cqr->startdev != cqr->block->base)) {
                dasd_eckd_reset_ccw_to_base_io(cqr);
                cqr->startdev = cqr->block->base;
                cqr->lpm = dasd_path_get_opm(cqr->block->base);
        }
};

static dasd_erp_fn_t
dasd_eckd_erp_action(struct dasd_ccw_req * cqr)
{
        struct dasd_device *device = (struct dasd_device *) cqr->startdev;
        struct ccw_device *cdev = device->cdev;

        switch (cdev->id.cu_type) {
        case 0x3990:
        case 0x2105:
        case 0x2107:
        case 0x1750:
                return dasd_3990_erp_action;
        case 0x9343:
        case 0x3880:
        default:
                return dasd_default_erp_action;
        }
}

static dasd_erp_fn_t
dasd_eckd_erp_postaction(struct dasd_ccw_req * cqr)
{
        return dasd_default_erp_postaction;
}

static void dasd_eckd_check_for_device_change(struct dasd_device *device,
                                              struct dasd_ccw_req *cqr,
                                              struct irb *irb)
{
        char mask;
        char *sense = NULL;
        struct dasd_eckd_private *private = device->private;

        /* first of all check for state change pending interrupt */
        mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
        if ((scsw_dstat(&irb->scsw) & mask) == mask) {
                /*
                 * for alias only, not in offline processing
                 * and only if not suspended
                 */
                if (!device->block && private->lcu &&
                    device->state == DASD_STATE_ONLINE &&
                    !test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
                    !test_bit(DASD_FLAG_SUSPENDED, &device->flags)) {
                        /* schedule worker to reload device */
                        dasd_reload_device(device);
                }
                dasd_generic_handle_state_change(device);
                return;
        }

        sense = dasd_get_sense(irb);
        if (!sense)
                return;

        /* summary unit check */
        if ((sense[27] & DASD_SENSE_BIT_0) && (sense[7] == 0x0D) &&
            (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK)) {
                if (test_and_set_bit(DASD_FLAG_SUC, &device->flags)) {
                        DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                                      "eckd suc: device already notified");
                        return;
                }
                sense = dasd_get_sense(irb);
                if (!sense) {
                        DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                                      "eckd suc: no reason code available");
                        clear_bit(DASD_FLAG_SUC, &device->flags);
                        return;

                }
                private->suc_reason = sense[8];
                DBF_DEV_EVENT(DBF_NOTICE, device, "%s %x",
                              "eckd handle summary unit check: reason",
                              private->suc_reason);
                dasd_get_device(device);
                if (!schedule_work(&device->suc_work))
                        dasd_put_device(device);

                return;
        }