// SPDX-License-Identifier: GPL-2.0
/*
 * 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):"

/*
 * 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);

static struct {
        struct dasd_ccw_req cqr;
        struct ccw1 ccw[2];
        char data[40];
} *dasd_vol_info_req;
static DEFINE_MUTEX(dasd_vol_info_mutex);

struct ext_pool_exhaust_work_data {
        struct work_struct worker;
        struct dasd_device *device;
        struct dasd_device *base;
};

/* definitions for the path verification worker */
struct pe_handler_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;
        __u8 fcsecpm;
};
static struct pe_handler_work_data *pe_handler_worker;
static DEFINE_MUTEX(dasd_pe_handler_mutex);

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

static int dasd_eckd_ext_pool_id(struct dasd_device *);
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);
        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, 1 };
static const int count_area_rec[] = { 1, 2, 3, 4, 1 };

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;
}

/*
 * calculate failing track from sense data depending if
 * it is an EAV device or not
 */
static int dasd_eckd_track_from_irb(struct irb *irb, struct dasd_device *device,
                                    sector_t *track)
{
        struct dasd_eckd_private *private = device->private;
        u8 *sense = NULL;
        u32 cyl;
        u8 head;

        sense = dasd_get_sense(irb);
        if (!sense) {
                DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                              "ESE error no sense data\n");
                return -EINVAL;
        }
        if (!(sense[27] & DASD_SENSE_BIT_2)) {
                DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                              "ESE error no valid track data\n");
                return -EINVAL;
        }

        if (sense[27] & DASD_SENSE_BIT_3) {
                /* enhanced addressing */
                cyl = sense[30] << 20;
                cyl |= (sense[31] & 0xF0) << 12;
                cyl |= sense[28] << 8;
                cyl |= sense[29];
        } else {
                cyl = sense[29] << 8;
                cyl |= sense[30];
        }
        head = sense[31] & 0x0F;
        *track = cyl * private->rdc_data.trk_per_cyl + head;
        return 0;
}

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

        rc = get_phys_clock(&data->ep_sys_time);
        /*
         * Ignore return code if XRC is not supported or
         * sync clock is switched off
         */
        if ((rc && !private->rdc_data.facilities.XRC_supported) ||
            rc == -EOPNOTSUPP || rc == -EACCES)
                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' */

        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 = set_timestamp(ccw, data, device);
                break;
        case DASD_ECKD_CCW_WRITE_CKD:
        case DASD_ECKD_CCW_WRITE_CKD_MT:
                data->attributes.operation = DASD_BYPASS_CACHE;
                rc = set_timestamp(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 = set_timestamp(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 = set_timestamp(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_PAV_ALIAS)
                pfxdata->validity.verify_base = 1;

        if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
                pfxdata->validity.verify_base = 1;
                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->serial,
               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, NULL);
        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_store_conf_data(struct dasd_device *device,
                                      struct dasd_conf_data *conf_data, int chp)
{
        struct dasd_eckd_private *private = device->private;
        struct channel_path_desc_fmt0 *chp_desc;
        struct subchannel_id sch_id;
        void *cdp;

        /*
         * path handling and read_conf allocate data
         * free it before replacing the pointer
         * also replace the old private->conf_data pointer
         * with the new one if this points to the same data
         */
        cdp = device->path[chp].conf_data;
        if (private->conf_data == cdp) {
                private->conf_data = (void *)conf_data;
                dasd_eckd_identify_conf_parts(private);
        }
        ccw_device_get_schid(device->cdev, &sch_id);
        device->path[chp].conf_data = conf_data;
        device->path[chp].cssid = sch_id.cssid;
        device->path[chp].ssid = sch_id.ssid;
        chp_desc = ccw_device_get_chp_desc(device->cdev, chp);
        if (chp_desc)
                device->path[chp].chpid = chp_desc->chpid;
        kfree(chp_desc);
        kfree(cdp);
}

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;
                dasd_path_notoper(device, i);
        }
}

static void dasd_eckd_read_fc_security(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        u8 esm_valid;
        u8 esm[8];
        int chp;
        int rc;

        rc = chsc_scud(private->uid.ssid, (u64 *)esm, &esm_valid);
        if (rc) {
                for (chp = 0; chp < 8; chp++)
                        device->path[chp].fc_security = 0;
                return;
        }

        for (chp = 0; chp < 8; chp++) {
                if (esm_valid & (0x80 >> chp))
                        device->path[chp].fc_security = esm[chp];
                else
                        device->path[chp].fc_security = 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];

        private = device->private;
        opm = ccw_device_get_path_mask(device->cdev);
        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;
                        }
                        /*
                         * 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;
                        }
                        path_private.conf_data = NULL;
                        path_private.conf_len = 0;
                }

                pos = pathmask_to_pos(lpm);
                dasd_eckd_store_conf_data(device, conf_data, pos);

                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);
                }
        }

        dasd_eckd_read_fc_security(device);

        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;
        unsigned int mdc;
        int tpm;

        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;
        unsigned 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 pe_handler_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 dasd_eckd_path_available_action(struct dasd_device *device,
                                            struct pe_handler_work_data *data)
{
        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;
        struct dasd_conf_data *conf_data;
        unsigned long flags;
        char print_uid[60];
        int rc, pos;

        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;
                        }
                }

                conf_data = kzalloc(DASD_ECKD_RCD_DATA_SIZE, GFP_KERNEL);
                if (conf_data) {
                        memcpy(conf_data, data->rcd_buffer,
                               DASD_ECKD_RCD_DATA_SIZE);
                }
                pos = pathmask_to_pos(lpm);
                dasd_eckd_store_conf_data(device, conf_data, pos);

                /*
                 * 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);

                dasd_path_create_kobj(device, pos);
        }
}

static void do_pe_handler_work(struct work_struct *work)
{
        struct pe_handler_work_data *data;
        struct dasd_device *device;

        data = container_of(work, struct pe_handler_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;
        }

        if (data->tbvpm)
                dasd_eckd_path_available_action(device, data);
        if (data->fcsecpm)
                dasd_eckd_read_fc_security(device);

        clear_bit(DASD_FLAG_PATH_VERIFY, &device->flags);
        dasd_put_device(device);
        if (data->isglobal)
                mutex_unlock(&dasd_pe_handler_mutex);
        else
                kfree(data);
}

static int dasd_eckd_pe_handler(struct dasd_device *device,
                                __u8 tbvpm, __u8 fcsecpm)
{
        struct pe_handler_work_data *data;

        data = kmalloc(sizeof(*data), GFP_ATOMIC | GFP_DMA);
        if (!data) {
                if (mutex_trylock(&dasd_pe_handler_mutex)) {
                        data = pe_handler_worker;
                        data->isglobal = 1;
                } else {
                        return -ENOMEM;
                }
        } else {
                memset(data, 0, sizeof(*data));
                data->isglobal = 0;
        }
        INIT_WORK(&data->worker, do_pe_handler_work);
        dasd_get_device(device);
        data->device = device;
        data->tbvpm = tbvpm;
        data->fcsecpm = fcsecpm;
        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, NULL);
        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;
}

/* Read Volume Information - Volume Storage Query */
static int dasd_eckd_read_vol_info(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        struct dasd_psf_prssd_data *prssdp;
        struct dasd_rssd_vsq *vsq;
        struct dasd_ccw_req *cqr;
        struct ccw1 *ccw;
        int useglobal;
        int rc;

        /* This command cannot be executed on an alias device */
        if (private->uid.type == UA_BASE_PAV_ALIAS ||
            private->uid.type == UA_HYPER_PAV_ALIAS)
                return 0;

        useglobal = 0;
        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2 /* PSF + RSSD */,
                                   sizeof(*prssdp) + sizeof(*vsq), device, NULL);
        if (IS_ERR(cqr)) {
                DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                "Could not allocate initialization request");
                mutex_lock(&dasd_vol_info_mutex);
                useglobal = 1;
                cqr = &dasd_vol_info_req->cqr;
                memset(cqr, 0, sizeof(*cqr));
                memset(dasd_vol_info_req, 0, sizeof(*dasd_vol_info_req));
                cqr->cpaddr = &dasd_vol_info_req->ccw;
                cqr->data = &dasd_vol_info_req->data;
                cqr->magic = DASD_ECKD_MAGIC;
        }

        /* Prepare for Read Subsystem Data */
        prssdp = cqr->data;
        prssdp->order = PSF_ORDER_PRSSD;
        prssdp->suborder = PSF_SUBORDER_VSQ;    /* Volume Storage Query */
        prssdp->lss = private->ned->ID;
        prssdp->volume = private->ned->unit_addr;

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

        /* Read Subsystem Data - Volume Storage Query */
        vsq = (struct dasd_rssd_vsq *)(prssdp + 1);
        memset(vsq, 0, sizeof(*vsq));

        ccw++;
        ccw->cmd_code = DASD_ECKD_CCW_RSSD;
        ccw->count = sizeof(*vsq);
        ccw->flags |= CCW_FLAG_SLI;
        ccw->cda = (__u32)(addr_t)vsq;

        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        cqr->startdev = device;
        cqr->memdev = device;
        cqr->block = NULL;
        cqr->retries = 256;
        cqr->expires = device->default_expires * HZ;
        /* The command might not be supported. Suppress the error output */
        __set_bit(DASD_CQR_SUPPRESS_CR, &cqr->flags);

        rc = dasd_sleep_on_interruptible(cqr);
        if (rc == 0) {
                memcpy(&private->vsq, vsq, sizeof(*vsq));
        } else {
                DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
                                "Reading the volume storage information failed with rc=%d", rc);
        }

        if (useglobal)
                mutex_unlock(&dasd_vol_info_mutex);
        else
                dasd_sfree_request(cqr, cqr->memdev);

        return rc;
}

static int dasd_eckd_is_ese(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;

        return private->vsq.vol_info.ese;
}

static int dasd_eckd_ext_pool_id(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;

        return private->vsq.extent_pool_id;
}

/*
 * This value represents the total amount of available space. As more space is
 * allocated by ESE volumes, this value will decrease.
 * The data for this value is therefore updated on any call.
 */
static int dasd_eckd_space_configured(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        int rc;

        rc = dasd_eckd_read_vol_info(device);

        return rc ? : private->vsq.space_configured;
}

/*
 * The value of space allocated by an ESE volume may have changed and is
 * therefore updated on any call.
 */
static int dasd_eckd_space_allocated(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        int rc;

        rc = dasd_eckd_read_vol_info(device);

        return rc ? : private->vsq.space_allocated;
}

static int dasd_eckd_logical_capacity(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;

        return private->vsq.logical_capacity;
}

static void dasd_eckd_ext_pool_exhaust_work(struct work_struct *work)
{
        struct ext_pool_exhaust_work_data *data;
        struct dasd_device *device;
        struct dasd_device *base;

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

        if (!base)
                base = device;
        if (dasd_eckd_space_configured(base) != 0) {
                dasd_generic_space_avail(device);
        } else {
                dev_warn(&device->cdev->dev, "No space left in the extent pool\n");
                DBF_DEV_EVENT(DBF_WARNING, device, "%s", "out of space");
        }

        dasd_put_device(device);
        kfree(data);
}

static int dasd_eckd_ext_pool_exhaust(struct dasd_device *device,
                                      struct dasd_ccw_req *cqr)
{
        struct ext_pool_exhaust_work_data *data;

        data = kzalloc(sizeof(*data), GFP_ATOMIC);
        if (!data)
                return -ENOMEM;
        INIT_WORK(&data->worker, dasd_eckd_ext_pool_exhaust_work);
        dasd_get_device(device);
        data->device = device;

        if (cqr->block)
                data->base = cqr->block->base;
        else if (cqr->basedev)
                data->base = cqr->basedev;
        else
                data->base = NULL;

        schedule_work(&data->worker);

        return 0;
}

static void dasd_eckd_cpy_ext_pool_data(struct dasd_device *device,
                                        struct dasd_rssd_lcq *lcq)
{
        struct dasd_eckd_private *private = device->private;
        int pool_id = dasd_eckd_ext_pool_id(device);
        struct dasd_ext_pool_sum eps;
        int i;

        for (i = 0; i < lcq->pool_count; i++) {
                eps = lcq->ext_pool_sum[i];
                if (eps.pool_id == pool_id) {
                        memcpy(&private->eps, &eps,
                               sizeof(struct dasd_ext_pool_sum));
                }
        }
}

/* Read Extent Pool Information - Logical Configuration Query */
static int dasd_eckd_read_ext_pool_info(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        struct dasd_psf_prssd_data *prssdp;
        struct dasd_rssd_lcq *lcq;
        struct dasd_ccw_req *cqr;
        struct ccw1 *ccw;
        int rc;

        /* This command cannot be executed on an alias device */
        if (private->uid.type == UA_BASE_PAV_ALIAS ||
            private->uid.type == UA_HYPER_PAV_ALIAS)
                return 0;

        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2 /* PSF + RSSD */,
                                   sizeof(*prssdp) + sizeof(*lcq), device, NULL);
        if (IS_ERR(cqr)) {
                DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                "Could not allocate initialization request");
                return PTR_ERR(cqr);
        }

        /* Prepare for Read Subsystem Data */
        prssdp = cqr->data;
        memset(prssdp, 0, sizeof(*prssdp));
        prssdp->order = PSF_ORDER_PRSSD;
        prssdp->suborder = PSF_SUBORDER_LCQ;    /* Logical Configuration Query */

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

        lcq = (struct dasd_rssd_lcq *)(prssdp + 1);
        memset(lcq, 0, sizeof(*lcq));

        ccw++;
        ccw->cmd_code = DASD_ECKD_CCW_RSSD;
        ccw->count = sizeof(*lcq);
        ccw->flags |= CCW_FLAG_SLI;
        ccw->cda = (__u32)(addr_t)lcq;

        cqr->buildclk = get_tod_clock();
        cqr->status = DASD_CQR_FILLED;
        cqr->startdev = device;
        cqr->memdev = device;
        cqr->block = NULL;
        cqr->retries = 256;
        cqr->expires = device->default_expires * HZ;
        /* The command might not be supported. Suppress the error output */
        __set_bit(DASD_CQR_SUPPRESS_CR, &cqr->flags);

        rc = dasd_sleep_on_interruptible(cqr);
        if (rc == 0) {
                dasd_eckd_cpy_ext_pool_data(device, lcq);
        } else {
                DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
                                "Reading the logical configuration failed with rc=%d", rc);
        }

        dasd_sfree_request(cqr, cqr->memdev);

        return rc;
}

/*
 * Depending on the device type, the extent size is specified either as
 * cylinders per extent (CKD) or size per extent (FBA)
 * A 1GB size corresponds to 1113cyl, and 16MB to 21cyl.
 */
static int dasd_eckd_ext_size(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;
        struct dasd_ext_pool_sum eps = private->eps;

        if (!eps.flags.extent_size_valid)
                return 0;
        if (eps.extent_size.size_1G)
                return 1113;
        if (eps.extent_size.size_16M)
                return 21;

        return 0;
}

static int dasd_eckd_ext_pool_warn_thrshld(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;

        return private->eps.warn_thrshld;
}

static int dasd_eckd_ext_pool_cap_at_warnlevel(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;

        return private->eps.flags.capacity_at_warnlevel;
}

/*
 * Extent Pool out of space
 */
static int dasd_eckd_ext_pool_oos(struct dasd_device *device)
{
        struct dasd_eckd_private *private = device->private;

        return private->eps.flags.pool_oos;
}

/*
 * 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, NULL);

        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)