tape_3590.c

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/*
 *    tape device discipline for 3590 tapes.
 *
 *    Copyright IBM Corp. 2001, 2009
 *    Author(s): Stefan Bader <[email protected]>
 *       Michael Holzheu <[email protected]>
 *       Martin Schwidefsky <[email protected]>
 */

#define KMSG_COMPONENT "tape_3590"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bio.h>
#include <asm/ebcdic.h>

#define TAPE_DBF_AREA   tape_3590_dbf
#define BUFSIZE 512 /* size of buffers for dynamic generated messages */

#include "tape.h"
#include "tape_std.h"
#include "tape_3590.h"

static struct workqueue_struct *tape_3590_wq;

/*
 * Pointer to debug area.
 */
debug_info_t *TAPE_DBF_AREA = NULL;
EXPORT_SYMBOL(TAPE_DBF_AREA);

/*******************************************************************
 * Error Recovery functions:
 * - Read Opposite:      implemented
 * - Read Device (buffered) log: BRA
 * - Read Library log:       BRA
 * - Swap Devices:       BRA
 * - Long Busy:          implemented
 * - Special Intercept:      BRA
 * - Read Alternate:         implemented
 *******************************************************************/

static const char *tape_3590_msg[TAPE_3590_MAX_MSG] = {
    [0x00] = "",
    [0x10] = "Lost Sense",
    [0x11] = "Assigned Elsewhere",
    [0x12] = "Allegiance Reset",
    [0x13] = "Shared Access Violation",
    [0x20] = "Command Reject",
    [0x21] = "Configuration Error",
    [0x22] = "Protection Exception",
    [0x23] = "Write Protect",
    [0x24] = "Write Length",
    [0x25] = "Read-Only Format",
    [0x31] = "Beginning of Partition",
    [0x33] = "End of Partition",
    [0x34] = "End of Data",
    [0x35] = "Block not found",
    [0x40] = "Device Intervention",
    [0x41] = "Loader Intervention",
    [0x42] = "Library Intervention",
    [0x50] = "Write Error",
    [0x51] = "Erase Error",
    [0x52] = "Formatting Error",
    [0x53] = "Read Error",
    [0x54] = "Unsupported Format",
    [0x55] = "No Formatting",
    [0x56] = "Positioning lost",
    [0x57] = "Read Length",
    [0x60] = "Unsupported Medium",
    [0x61] = "Medium Length Error",
    [0x62] = "Medium removed",
    [0x64] = "Load Check",
    [0x65] = "Unload Check",
    [0x70] = "Equipment Check",
    [0x71] = "Bus out Check",
    [0x72] = "Protocol Error",
    [0x73] = "Interface Error",
    [0x74] = "Overrun",
    [0x75] = "Halt Signal",
    [0x90] = "Device fenced",
    [0x91] = "Device Path fenced",
    [0xa0] = "Volume misplaced",
    [0xa1] = "Volume inaccessible",
    [0xa2] = "Volume in input",
    [0xa3] = "Volume ejected",
    [0xa4] = "All categories reserved",
    [0xa5] = "Duplicate Volume",
    [0xa6] = "Library Manager Offline",
    [0xa7] = "Library Output Station full",
    [0xa8] = "Vision System non-operational",
    [0xa9] = "Library Manager Equipment Check",
    [0xaa] = "Library Equipment Check",
    [0xab] = "All Library Cells full",
    [0xac] = "No Cleaner Volumes in Library",
    [0xad] = "I/O Station door open",
    [0xae] = "Subsystem environmental alert",
};

static int crypt_supported(struct tape_device *device)
{
    return TAPE390_CRYPT_SUPPORTED(TAPE_3590_CRYPT_INFO(device));
}

static int crypt_enabled(struct tape_device *device)
{
    return TAPE390_CRYPT_ON(TAPE_3590_CRYPT_INFO(device));
}

static void ext_to_int_kekl(struct tape390_kekl *in,
                struct tape3592_kekl *out)
{
    int i;

    memset(out, 0, sizeof(*out));
    if (in->type == TAPE390_KEKL_TYPE_HASH)
        out->flags |= 0x40;
    if (in->type_on_tape == TAPE390_KEKL_TYPE_HASH)
        out->flags |= 0x80;
    strncpy(out->label, in->label, 64);
    for (i = strlen(in->label); i < sizeof(out->label); i++)
        out->label[i] = ' ';
    ASCEBC(out->label, sizeof(out->label));
}

static void int_to_ext_kekl(struct tape3592_kekl *in,
                struct tape390_kekl *out)
{
    memset(out, 0, sizeof(*out));
    if(in->flags & 0x40)
        out->type = TAPE390_KEKL_TYPE_HASH;
    else
        out->type = TAPE390_KEKL_TYPE_LABEL;
    if(in->flags & 0x80)
        out->type_on_tape = TAPE390_KEKL_TYPE_HASH;
    else
        out->type_on_tape = TAPE390_KEKL_TYPE_LABEL;
    memcpy(out->label, in->label, sizeof(in->label));
    EBCASC(out->label, sizeof(in->label));
    strim(out->label);
}

static void int_to_ext_kekl_pair(struct tape3592_kekl_pair *in,
                 struct tape390_kekl_pair *out)
{
    if (in->count == 0) {
        out->kekl[0].type = TAPE390_KEKL_TYPE_NONE;
        out->kekl[0].type_on_tape = TAPE390_KEKL_TYPE_NONE;
        out->kekl[1].type = TAPE390_KEKL_TYPE_NONE;
        out->kekl[1].type_on_tape = TAPE390_KEKL_TYPE_NONE;
    } else if (in->count == 1) {
        int_to_ext_kekl(&in->kekl[0], &out->kekl[0]);
        out->kekl[1].type = TAPE390_KEKL_TYPE_NONE;
        out->kekl[1].type_on_tape = TAPE390_KEKL_TYPE_NONE;
    } else if (in->count == 2) {
        int_to_ext_kekl(&in->kekl[0], &out->kekl[0]);
        int_to_ext_kekl(&in->kekl[1], &out->kekl[1]);
    } else {
        printk("Invalid KEKL number: %d\n", in->count);
        BUG();
    }
}

static int check_ext_kekl(struct tape390_kekl *kekl)
{
    if (kekl->type == TAPE390_KEKL_TYPE_NONE)
        goto invalid;
    if (kekl->type > TAPE390_KEKL_TYPE_HASH)
        goto invalid;
    if (kekl->type_on_tape == TAPE390_KEKL_TYPE_NONE)
        goto invalid;
    if (kekl->type_on_tape > TAPE390_KEKL_TYPE_HASH)
        goto invalid;
    if ((kekl->type == TAPE390_KEKL_TYPE_HASH) &&
        (kekl->type_on_tape == TAPE390_KEKL_TYPE_LABEL))
        goto invalid;

    return 0;
invalid:
    return -EINVAL;
}

static int check_ext_kekl_pair(struct tape390_kekl_pair *kekls)
{
    if (check_ext_kekl(&kekls->kekl[0]))
        goto invalid;
    if (check_ext_kekl(&kekls->kekl[1]))
        goto invalid;

    return 0;
invalid:
    return -EINVAL;
}

/*
 * Query KEKLs
 */
static int tape_3592_kekl_query(struct tape_device *device,
                struct tape390_kekl_pair *ext_kekls)
{
    struct tape_request *request;
    struct tape3592_kekl_query_order *order;
    struct tape3592_kekl_query_data *int_kekls;
    int rc;

    DBF_EVENT(6, "tape3592_kekl_query\n");
    int_kekls = kmalloc(sizeof(*int_kekls), GFP_KERNEL|GFP_DMA);
    if (!int_kekls)
        return -ENOMEM;
    request = tape_alloc_request(2, sizeof(*order));
    if (IS_ERR(request)) {
        rc = PTR_ERR(request);
        goto fail_malloc;
    }
    order = request->cpdata;
    memset(order,0,sizeof(*order));
    order->code = 0xe2;
    order->max_count = 2;
    request->op = TO_KEKL_QUERY;
    tape_ccw_cc(request->cpaddr, PERF_SUBSYS_FUNC, sizeof(*order), order);
    tape_ccw_end(request->cpaddr + 1, READ_SS_DATA, sizeof(*int_kekls),
             int_kekls);
    rc = tape_do_io(device, request);
    if (rc)
        goto fail_request;
    int_to_ext_kekl_pair(&int_kekls->kekls, ext_kekls);

    rc = 0;
fail_request:
    tape_free_request(request);
fail_malloc:
    kfree(int_kekls);
    return rc;
}

/*
 * IOCTL: Query KEKLs
 */
static int tape_3592_ioctl_kekl_query(struct tape_device *device,
                      unsigned long arg)
{
    int rc;
    struct tape390_kekl_pair *ext_kekls;

    DBF_EVENT(6, "tape_3592_ioctl_kekl_query\n");
    if (!crypt_supported(device))
        return -ENOSYS;
    if (!crypt_enabled(device))
        return -EUNATCH;
    ext_kekls = kmalloc(sizeof(*ext_kekls), GFP_KERNEL);
    if (!ext_kekls)
        return -ENOMEM;
    rc = tape_3592_kekl_query(device, ext_kekls);
    if (rc != 0)
        goto fail;
    if (copy_to_user((char __user *) arg, ext_kekls, sizeof(*ext_kekls))) {
        rc = -EFAULT;
        goto fail;
    }
    rc = 0;
fail:
    kfree(ext_kekls);
    return rc;
}

static int tape_3590_mttell(struct tape_device *device, int mt_count);

/*
 * Set KEKLs
 */
static int tape_3592_kekl_set(struct tape_device *device,
                  struct tape390_kekl_pair *ext_kekls)
{
    struct tape_request *request;
    struct tape3592_kekl_set_order *order;

    DBF_EVENT(6, "tape3592_kekl_set\n");
    if (check_ext_kekl_pair(ext_kekls)) {
        DBF_EVENT(6, "invalid kekls\n");
        return -EINVAL;
    }
    if (tape_3590_mttell(device, 0) != 0)
        return -EBADSLT;
    request = tape_alloc_request(1, sizeof(*order));
    if (IS_ERR(request))
        return PTR_ERR(request);
    order = request->cpdata;
    memset(order, 0, sizeof(*order));
    order->code = 0xe3;
    order->kekls.count = 2;
    ext_to_int_kekl(&ext_kekls->kekl[0], &order->kekls.kekl[0]);
    ext_to_int_kekl(&ext_kekls->kekl[1], &order->kekls.kekl[1]);
    request->op = TO_KEKL_SET;
    tape_ccw_end(request->cpaddr, PERF_SUBSYS_FUNC, sizeof(*order), order);

    return tape_do_io_free(device, request);
}

/*
 * IOCTL: Set KEKLs
 */
static int tape_3592_ioctl_kekl_set(struct tape_device *device,
                    unsigned long arg)
{
    int rc;
    struct tape390_kekl_pair *ext_kekls;

    DBF_EVENT(6, "tape_3592_ioctl_kekl_set\n");
    if (!crypt_supported(device))
        return -ENOSYS;
    if (!crypt_enabled(device))
        return -EUNATCH;
    ext_kekls = kmalloc(sizeof(*ext_kekls), GFP_KERNEL);
    if (!ext_kekls)
        return -ENOMEM;
    if (copy_from_user(ext_kekls, (char __user *)arg, sizeof(*ext_kekls))) {
        rc = -EFAULT;
        goto out;
    }
    rc = tape_3592_kekl_set(device, ext_kekls);
out:
    kfree(ext_kekls);
    return rc;
}

/*
 * Enable encryption
 */
static struct tape_request *__tape_3592_enable_crypt(struct tape_device *device)
{
    struct tape_request *request;
    char *data;

    DBF_EVENT(6, "tape_3592_enable_crypt\n");
    if (!crypt_supported(device))
        return ERR_PTR(-ENOSYS);
    request = tape_alloc_request(2, 72);
    if (IS_ERR(request))
        return request;
    data = request->cpdata;
    memset(data,0,72);

    data[0]       = 0x05;
    data[36 + 0]  = 0x03;
    data[36 + 1]  = 0x03;
    data[36 + 4]  = 0x40;
    data[36 + 6]  = 0x01;
    data[36 + 14] = 0x2f;
    data[36 + 18] = 0xc3;
    data[36 + 35] = 0x72;
    request->op = TO_CRYPT_ON;
    tape_ccw_cc(request->cpaddr, MODE_SET_CB, 36, data);
    tape_ccw_end(request->cpaddr + 1, MODE_SET_CB, 36, data + 36);
    return request;
}

static int tape_3592_enable_crypt(struct tape_device *device)
{
    struct tape_request *request;

    request = __tape_3592_enable_crypt(device);
    if (IS_ERR(request))
        return PTR_ERR(request);
    return tape_do_io_free(device, request);
}

static void tape_3592_enable_crypt_async(struct tape_device *device)
{
    struct tape_request *request;

    request = __tape_3592_enable_crypt(device);
    if (!IS_ERR(request))
        tape_do_io_async_free(device, request);
}

/*
 * Disable encryption
 */
static struct tape_request *__tape_3592_disable_crypt(struct tape_device *device)
{
    struct tape_request *request;
    char *data;

    DBF_EVENT(6, "tape_3592_disable_crypt\n");
    if (!crypt_supported(device))
        return ERR_PTR(-ENOSYS);
    request = tape_alloc_request(2, 72);
    if (IS_ERR(request))
        return request;
    data = request->cpdata;
    memset(data,0,72);

    data[0]       = 0x05;
    data[36 + 0]  = 0x03;
    data[36 + 1]  = 0x03;
    data[36 + 35] = 0x32;

    request->op = TO_CRYPT_OFF;
    tape_ccw_cc(request->cpaddr, MODE_SET_CB, 36, data);
    tape_ccw_end(request->cpaddr + 1, MODE_SET_CB, 36, data + 36);

    return request;
}

static int tape_3592_disable_crypt(struct tape_device *device)
{
    struct tape_request *request;

    request = __tape_3592_disable_crypt(device);
    if (IS_ERR(request))
        return PTR_ERR(request);
    return tape_do_io_free(device, request);
}

static void tape_3592_disable_crypt_async(struct tape_device *device)
{
    struct tape_request *request;

    request = __tape_3592_disable_crypt(device);
    if (!IS_ERR(request))
        tape_do_io_async_free(device, request);
}

/*
 * IOCTL: Set encryption status
 */
static int tape_3592_ioctl_crypt_set(struct tape_device *device,
                     unsigned long arg)
{
    struct tape390_crypt_info info;

    DBF_EVENT(6, "tape_3592_ioctl_crypt_set\n");
    if (!crypt_supported(device))
        return -ENOSYS;
    if (copy_from_user(&info, (char __user *)arg, sizeof(info)))
        return -EFAULT;
    if (info.status & ~TAPE390_CRYPT_ON_MASK)
        return -EINVAL;
    if (info.status & TAPE390_CRYPT_ON_MASK)
        return tape_3592_enable_crypt(device);
    else
        return tape_3592_disable_crypt(device);
}

static int tape_3590_sense_medium(struct tape_device *device);

/*
 * IOCTL: Query enryption status
 */
static int tape_3592_ioctl_crypt_query(struct tape_device *device,
                       unsigned long arg)
{
    DBF_EVENT(6, "tape_3592_ioctl_crypt_query\n");
    if (!crypt_supported(device))
        return -ENOSYS;
    tape_3590_sense_medium(device);
    if (copy_to_user((char __user *) arg, &TAPE_3590_CRYPT_INFO(device),
        sizeof(TAPE_3590_CRYPT_INFO(device))))
        return -EFAULT;
    else
        return 0;
}

/*
 * 3590 IOCTL Overload
 */
static int
tape_3590_ioctl(struct tape_device *device, unsigned int cmd, unsigned long arg)
{
    switch (cmd) {
    case TAPE390_DISPLAY: {
        struct display_struct disp;

        if (copy_from_user(&disp, (char __user *) arg, sizeof(disp)))
            return -EFAULT;

        return tape_std_display(device, &disp);
    }
    case TAPE390_KEKL_SET:
        return tape_3592_ioctl_kekl_set(device, arg);
    case TAPE390_KEKL_QUERY:
        return tape_3592_ioctl_kekl_query(device, arg);
    case TAPE390_CRYPT_SET:
        return tape_3592_ioctl_crypt_set(device, arg);
    case TAPE390_CRYPT_QUERY:
        return tape_3592_ioctl_crypt_query(device, arg);
    default:
        return -EINVAL; /* no additional ioctls */
    }
}

/*
 * SENSE Medium: Get Sense data about medium state
 */
static int tape_3590_sense_medium(struct tape_device *device)
{
    struct tape_request *request;

    request = tape_alloc_request(1, 128);
    if (IS_ERR(request))
        return PTR_ERR(request);
    request->op = TO_MSEN;
    tape_ccw_end(request->cpaddr, MEDIUM_SENSE, 128, request->cpdata);
    return tape_do_io_free(device, request);
}

static void tape_3590_sense_medium_async(struct tape_device *device)
{
    struct tape_request *request;

    request = tape_alloc_request(1, 128);
    if (IS_ERR(request))
        return;
    request->op = TO_MSEN;
    tape_ccw_end(request->cpaddr, MEDIUM_SENSE, 128, request->cpdata);
    tape_do_io_async_free(device, request);
}

/*
 * MTTELL: Tell block. Return the number of block relative to current file.
 */
static int
tape_3590_mttell(struct tape_device *device, int mt_count)
{
    __u64 block_id;
    int rc;

    rc = tape_std_read_block_id(device, &block_id);
    if (rc)
        return rc;
    return block_id >> 32;
}

/*
 * MTSEEK: seek to the specified block.
 */
static int
tape_3590_mtseek(struct tape_device *device, int count)
{
    struct tape_request *request;

    DBF_EVENT(6, "xsee id: %x\n", count);
    request = tape_alloc_request(3, 4);
    if (IS_ERR(request))
        return PTR_ERR(request);
    request->op = TO_LBL;
    tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    *(__u32 *) request->cpdata = count;
    tape_ccw_cc(request->cpaddr + 1, LOCATE, 4, request->cpdata);
    tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
    return tape_do_io_free(device, request);
}

/*
 * Read Opposite Error Recovery Function:
 * Used, when Read Forward does not work
 */
static void
tape_3590_read_opposite(struct tape_device *device,
            struct tape_request *request)
{
    struct tape_3590_disc_data *data;

    /*
     * We have allocated 4 ccws in tape_std_read, so we can now
     * transform the request to a read backward, followed by a
     * forward space block.
     */
    request->op = TO_RBA;
    tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
    data = device->discdata;
    tape_ccw_cc_idal(request->cpaddr + 1, data->read_back_op,
             device->char_data.idal_buf);
    tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
    tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
    DBF_EVENT(6, "xrop ccwg\n");
}

/*
 * Read Attention Msg
 * This should be done after an interrupt with attention bit (0x80)
 * in device state.
 *
 * After a "read attention message" request there are two possible
 * results:
 *
 * 1. A unit check is presented, when attention sense is present (e.g. when
 * a medium has been unloaded). The attention sense comes then
 * together with the unit check. The recovery action is either "retry"
 * (in case there is an attention message pending) or "permanent error".
 *
 * 2. The attention msg is written to the "read subsystem data" buffer.
 * In this case we probably should print it to the console.
 */
static void tape_3590_read_attmsg_async(struct tape_device *device)
{
    struct tape_request *request;
    char *buf;

    request = tape_alloc_request(3, 4096);
    if (IS_ERR(request))
        return;
    request->op = TO_READ_ATTMSG;
    buf = request->cpdata;
    buf[0] = PREP_RD_SS_DATA;
    buf[6] = RD_ATTMSG; /* read att msg */
    tape_ccw_cc(request->cpaddr, PERFORM_SS_FUNC, 12, buf);
    tape_ccw_cc(request->cpaddr + 1, READ_SS_DATA, 4096 - 12, buf + 12);
    tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
    tape_do_io_async_free(device, request);
}

/*
 * These functions are used to schedule follow-up actions from within an
 * interrupt context (like unsolicited interrupts).
 * Note: the work handler is called by the system work queue. The tape
 * commands started by the handler need to be asynchrounous, otherwise
 * a deadlock can occur e.g. in case of a deferred cc=1 (see __tape_do_irq).
 */
struct work_handler_data {
    struct tape_device *device;
    enum tape_op        op;
    struct work_struct  work;
};

static void
tape_3590_work_handler(struct work_struct *work)
{
    struct work_handler_data *p =
        container_of(work, struct work_handler_data, work);

    switch (p->op) {
    case TO_MSEN:
        tape_3590_sense_medium_async(p->device);
        break;
    case TO_READ_ATTMSG:
        tape_3590_read_attmsg_async(p->device);
        break;
    case TO_CRYPT_ON:
        tape_3592_enable_crypt_async(p->device);
        break;
    case TO_CRYPT_OFF:
        tape_3592_disable_crypt_async(p->device);
        break;
    default:
        DBF_EVENT(3, "T3590: work handler undefined for "
              "operation 0x%02x\n", p->op);
    }
    tape_put_device(p->device);
    kfree(p);
}

static int
tape_3590_schedule_work(struct tape_device *device, enum tape_op op)
{
    struct work_handler_data *p;

    if ((p = kzalloc(sizeof(*p), GFP_ATOMIC)) == NULL)
        return -ENOMEM;

    INIT_WORK(&p->work, tape_3590_work_handler);

    p->device = tape_get_device(device);
    p->op = op;

    queue_work(tape_3590_wq, &p->work);
    return 0;
}

static void tape_3590_med_state_set(struct tape_device *device,
                    struct tape_3590_med_sense *sense)
{
    struct tape390_crypt_info *c_info;

    c_info = &TAPE_3590_CRYPT_INFO(device);

    DBF_EVENT(6, "medium state: %x:%x\n", sense->macst, sense->masst);
    switch (sense->macst) {
    case 0x04:
    case 0x05:
    case 0x06:
        tape_med_state_set(device, MS_UNLOADED);
        TAPE_3590_CRYPT_INFO(device).medium_status = 0;
        return;
    case 0x08:
    case 0x09:
        tape_med_state_set(device, MS_LOADED);
        break;
    default:
        tape_med_state_set(device, MS_UNKNOWN);
        return;
    }
    c_info->medium_status |= TAPE390_MEDIUM_LOADED_MASK;
    if (sense->flags & MSENSE_CRYPT_MASK) {
        DBF_EVENT(6, "Medium is encrypted (%04x)\n", sense->flags);
        c_info->medium_status |= TAPE390_MEDIUM_ENCRYPTED_MASK;
    } else  {
        DBF_EVENT(6, "Medium is not encrypted %04x\n", sense->flags);
        c_info->medium_status &= ~TAPE390_MEDIUM_ENCRYPTED_MASK;
    }
}

/*
 * The done handler is called at device/channel end and wakes up the sleeping
 * process
 */
static int
tape_3590_done(struct tape_device *device, struct tape_request *request)
{

    DBF_EVENT(6, "%s done\n", tape_op_verbose[request->op]);

    switch (request->op) {
    case TO_BSB:
    case TO_BSF:
    case TO_DSE:
    case TO_FSB:
    case TO_FSF:
    case TO_LBL:
    case TO_RFO:
    case TO_RBA:
    case TO_REW:
    case TO_WRI:
    case TO_WTM:
    case TO_BLOCK:
    case TO_LOAD:
        tape_med_state_set(device, MS_LOADED);
        break;
    case TO_RUN:
        tape_med_state_set(device, MS_UNLOADED);
        tape_3590_schedule_work(device, TO_CRYPT_OFF);
        break;
    case TO_MSEN:
        tape_3590_med_state_set(device, request->cpdata);
        break;
    case TO_CRYPT_ON:
        TAPE_3590_CRYPT_INFO(device).status
            |= TAPE390_CRYPT_ON_MASK;
        *(device->modeset_byte) |= 0x03;
        break;
    case TO_CRYPT_OFF:
        TAPE_3590_CRYPT_INFO(device).status
            &= ~TAPE390_CRYPT_ON_MASK;
        *(device->modeset_byte) &= ~0x03;
        break;
    case TO_RBI:    /* RBI seems to succeed even without medium loaded. */
    case TO_NOP:    /* Same to NOP. */
    case TO_READ_CONFIG:
    case TO_READ_ATTMSG:
    case TO_DIS:
    case TO_ASSIGN:
    case TO_UNASSIGN:
    case TO_SIZE:
    case TO_KEKL_SET:
    case TO_KEKL_QUERY:
    case TO_RDC:
        break;
    }
    return TAPE_IO_SUCCESS;
}

/*
 * This function is called, when error recovery was successful
 */
static inline int
tape_3590_erp_succeded(struct tape_device *device, struct tape_request *request)
{
    DBF_EVENT(3, "Error Recovery successful for %s\n",
          tape_op_verbose[request->op]);
    return tape_3590_done(device, request);
}

/*
 * This function is called, when error recovery was not successful
 */
static inline int
tape_3590_erp_failed(struct tape_device *device, struct tape_request *request,
             struct irb *irb, int rc)
{
    DBF_EVENT(3, "Error Recovery failed for %s\n",
          tape_op_verbose[request->op]);
    tape_dump_sense_dbf(device, request, irb);
    return rc;
}

/*
 * Error Recovery do retry
 */
static inline int
tape_3590_erp_retry(struct tape_device *device, struct tape_request *request,
            struct irb *irb)
{
    DBF_EVENT(2, "Retry: %s\n", tape_op_verbose[request->op]);
    tape_dump_sense_dbf(device, request, irb);
    return TAPE_IO_RETRY;
}

/*
 * Handle unsolicited interrupts
 */
static int
tape_3590_unsolicited_irq(struct tape_device *device, struct irb *irb)
{
    if (irb->scsw.cmd.dstat == DEV_STAT_CHN_END)
        /* Probably result of halt ssch */
        return TAPE_IO_PENDING;
    else if (irb->scsw.cmd.dstat == 0x85)
        /* Device Ready */
        DBF_EVENT(3, "unsol.irq! tape ready: %08x\n", device->cdev_id);
    else if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
        tape_3590_schedule_work(device, TO_READ_ATTMSG);
    } else {
        DBF_EVENT(3, "unsol.irq! dev end: %08x\n", device->cdev_id);
        tape_dump_sense_dbf(device, NULL, irb);
    }
    /* check medium state */
    tape_3590_schedule_work(device, TO_MSEN);
    return TAPE_IO_SUCCESS;
}

/*
 * Basic Recovery routine
 */
static int
tape_3590_erp_basic(struct tape_device *device, struct tape_request *request,
            struct irb *irb, int rc)
{
    struct tape_3590_sense *sense;

    sense = (struct tape_3590_sense *) irb->ecw;

    switch (sense->bra) {
    case SENSE_BRA_PER:
        return tape_3590_erp_failed(device, request, irb, rc);
    case SENSE_BRA_CONT:
        return tape_3590_erp_succeded(device, request);
    case SENSE_BRA_RE:
        return tape_3590_erp_retry(device, request, irb);
    case SENSE_BRA_DRE:
        return tape_3590_erp_failed(device, request, irb, rc);
    default:
        BUG();
        return TAPE_IO_STOP;
    }
}

/*
 *  RDL: Read Device (buffered) log
 */
static int
tape_3590_erp_read_buf_log(struct tape_device *device,
               struct tape_request *request, struct irb *irb)
{
    /*
     * We just do the basic error recovery at the moment (retry).
     * Perhaps in the future, we read the log and dump it somewhere...
     */
    return tape_3590_erp_basic(device, request, irb, -EIO);
}

/*
 *  SWAP: Swap Devices
 */
static int
tape_3590_erp_swap(struct tape_device *device, struct tape_request *request,
           struct irb *irb)
{
    /*
     * This error recovery should swap the tapes
     * if the original has a problem. The operation
     * should proceed with the new tape... this
     * should probably be done in user space!
     */
    dev_warn (&device->cdev->dev, "The tape medium must be loaded into a "
        "different tape unit\n");
    return tape_3590_erp_basic(device, request, irb, -EIO);
}

/*
 *  LBY: Long Busy
 */
static int
tape_3590_erp_long_busy(struct tape_device *device,
            struct tape_request *request, struct irb *irb)
{
    DBF_EVENT(6, "Device is busy\n");
    return TAPE_IO_LONG_BUSY;
}

/*
 *  SPI: Special Intercept
 */
static int
tape_3590_erp_special_interrupt(struct tape_device *device,
                struct tape_request *request, struct irb *irb)
{
    return tape_3590_erp_basic(device, request, irb, -EIO);
}

/*
 *  RDA: Read Alternate
 */
static int
tape_3590_erp_read_alternate(struct tape_device *device,
                 struct tape_request *request, struct irb *irb)
{
    struct tape_3590_disc_data *data;

    /*
     * The issued Read Backward or Read Previous command is not
     * supported by the device
     * The recovery action should be to issue another command:
     * Read Revious: if Read Backward is not supported
     * Read Backward: if Read Previous is not supported
     */
    data = device->discdata;
    if (data->read_back_op == READ_PREVIOUS) {
        DBF_EVENT(2, "(%08x): No support for READ_PREVIOUS command\n",
              device->cdev_id);
        data->read_back_op = READ_BACKWARD;
    } else {
        DBF_EVENT(2, "(%08x): No support for READ_BACKWARD command\n",
              device->cdev_id);
        data->read_back_op = READ_PREVIOUS;
    }
    tape_3590_read_opposite(device, request);
    return tape_3590_erp_retry(device, request, irb);
}

/*
 * Error Recovery read opposite
 */
static int
tape_3590_erp_read_opposite(struct tape_device *device,
                struct tape_request *request, struct irb *irb)
{
    switch (request->op) {
    case TO_RFO:
        /*
         * We did read forward, but the data could not be read.
         * We will read backward and then skip forward again.
         */
        tape_3590_read_opposite(device, request);
        return tape_3590_erp_retry(device, request, irb);
    case TO_RBA:
        /* We tried to read forward and backward, but hat no success */
        return tape_3590_erp_failed(device, request, irb, -EIO);
        break;
    default:
        return tape_3590_erp_failed(device, request, irb, -EIO);
    }
}

/*
 * Print an MIM (Media Information  Message) (message code f0)
 */
static void
tape_3590_print_mim_msg_f0(struct tape_device *device, struct irb *irb)
{
    struct tape_3590_sense *sense;
    char *exception, *service;

    exception = kmalloc(BUFSIZE, GFP_ATOMIC);
    service = kmalloc(BUFSIZE, GFP_ATOMIC);

    if (!exception || !service)
        goto out_nomem;

    sense = (struct tape_3590_sense *) irb->ecw;
    /* Exception Message */
    switch (sense->fmt.f70.emc) {
    case 0x02:
        snprintf(exception, BUFSIZE, "Data degraded");
        break;
    case 0x03:
        snprintf(exception, BUFSIZE, "Data degraded in partion %i",
            sense->fmt.f70.mp);
        break;
    case 0x04:
        snprintf(exception, BUFSIZE, "Medium degraded");
        break;
    case 0x05:
        snprintf(exception, BUFSIZE, "Medium degraded in partition %i",
            sense->fmt.f70.mp);
        break;
    case 0x06:
        snprintf(exception, BUFSIZE, "Block 0 Error");
        break;
    case 0x07:
        snprintf(exception, BUFSIZE, "Medium Exception 0x%02x",
            sense->fmt.f70.md);
        break;
    default:
        snprintf(exception, BUFSIZE, "0x%02x",
            sense->fmt.f70.emc);
        break;
    }
    /* Service Message */
    switch (sense->fmt.f70.smc) {
    case 0x02:
        snprintf(service, BUFSIZE, "Reference Media maintenance "
            "procedure %i", sense->fmt.f70.md);
        break;
    default:
        snprintf(service, BUFSIZE, "0x%02x",
            sense->fmt.f70.smc);
        break;
    }

    dev_warn (&device->cdev->dev, "Tape media information: exception %s, "
        "service %s\n", exception, service);

out_nomem:
    kfree(exception);
    kfree(service);
}

/*
 * Print an I/O Subsystem Service Information Message (message code f1)
 */
static void
tape_3590_print_io_sim_msg_f1(struct tape_device *device, struct irb *irb)
{
    struct tape_3590_sense *sense;
    char *exception, *service;

    exception = kmalloc(BUFSIZE, GFP_ATOMIC);
    service = kmalloc(BUFSIZE, GFP_ATOMIC);

    if (!exception || !service)
        goto out_nomem;

    sense = (struct tape_3590_sense *) irb->ecw;
    /* Exception Message */
    switch (sense->fmt.f71.emc) {
    case 0x01:
        snprintf(exception, BUFSIZE, "Effect of failure is unknown");
        break;
    case 0x02:
        snprintf(exception, BUFSIZE, "CU Exception - no performance "
            "impact");
        break;
    case 0x03:
        snprintf(exception, BUFSIZE, "CU Exception on channel "
            "interface 0x%02x", sense->fmt.f71.md[0]);
        break;
    case 0x04:
        snprintf(exception, BUFSIZE, "CU Exception on device path "
            "0x%02x", sense->fmt.f71.md[0]);
        break;
    case 0x05:
        snprintf(exception, BUFSIZE, "CU Exception on library path "
            "0x%02x", sense->fmt.f71.md[0]);
        break;
    case 0x06:
        snprintf(exception, BUFSIZE, "CU Exception on node 0x%02x",
            sense->fmt.f71.md[0]);
        break;
    case 0x07:
        snprintf(exception, BUFSIZE, "CU Exception on partition "
            "0x%02x", sense->fmt.f71.md[0]);
        break;
    default:
        snprintf(exception, BUFSIZE, "0x%02x",
            sense->fmt.f71.emc);
    }
    /* Service Message */
    switch (sense->fmt.f71.smc) {
    case 0x01:
        snprintf(service, BUFSIZE, "Repair impact is unknown");
        break;
    case 0x02:
        snprintf(service, BUFSIZE, "Repair will not impact cu "
            "performance");
        break;
    case 0x03:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable node "
                "0x%x on CU", sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable "
                "nodes (0x%x-0x%x) on CU", sense->fmt.f71.md[1],
                sense->fmt.f71.md[2]);
        break;
    case 0x04:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable "
                "channel path 0x%x on CU",
                sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable cannel"
                " paths (0x%x-0x%x) on CU",
                sense->fmt.f71.md[1], sense->fmt.f71.md[2]);
        break;
    case 0x05:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable device"
                " path 0x%x on CU", sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable device"
                " paths (0x%x-0x%x) on CU",
                sense->fmt.f71.md[1], sense->fmt.f71.md[2]);
        break;
    case 0x06:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable "
                "library path 0x%x on CU",
                sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable "
                "library paths (0x%x-0x%x) on CU",
                sense->fmt.f71.md[1], sense->fmt.f71.md[2]);
        break;
    case 0x07:
        snprintf(service, BUFSIZE, "Repair will disable access to CU");
        break;
    default:
        snprintf(service, BUFSIZE, "0x%02x",
            sense->fmt.f71.smc);
    }

    dev_warn (&device->cdev->dev, "I/O subsystem information: exception"
        " %s, service %s\n", exception, service);
out_nomem:
    kfree(exception);
    kfree(service);
}

/*
 * Print an Device Subsystem Service Information Message (message code f2)
 */
static void
tape_3590_print_dev_sim_msg_f2(struct tape_device *device, struct irb *irb)
{
    struct tape_3590_sense *sense;
    char *exception, *service;

    exception = kmalloc(BUFSIZE, GFP_ATOMIC);
    service = kmalloc(BUFSIZE, GFP_ATOMIC);

    if (!exception || !service)
        goto out_nomem;

    sense = (struct tape_3590_sense *) irb->ecw;
    /* Exception Message */
    switch (sense->fmt.f71.emc) {
    case 0x01:
        snprintf(exception, BUFSIZE, "Effect of failure is unknown");
        break;
    case 0x02:
        snprintf(exception, BUFSIZE, "DV Exception - no performance"
            " impact");
        break;
    case 0x03:
        snprintf(exception, BUFSIZE, "DV Exception on channel "
            "interface 0x%02x", sense->fmt.f71.md[0]);
        break;
    case 0x04:
        snprintf(exception, BUFSIZE, "DV Exception on loader 0x%02x",
            sense->fmt.f71.md[0]);
        break;
    case 0x05:
        snprintf(exception, BUFSIZE, "DV Exception on message display"
            " 0x%02x", sense->fmt.f71.md[0]);
        break;
    case 0x06:
        snprintf(exception, BUFSIZE, "DV Exception in tape path");
        break;
    case 0x07:
        snprintf(exception, BUFSIZE, "DV Exception in drive");
        break;
    default:
        snprintf(exception, BUFSIZE, "0x%02x",
            sense->fmt.f71.emc);
    }
    /* Service Message */
    switch (sense->fmt.f71.smc) {
    case 0x01:
        snprintf(service, BUFSIZE, "Repair impact is unknown");
        break;
    case 0x02:
        snprintf(service, BUFSIZE, "Repair will not impact device "
            "performance");
        break;
    case 0x03:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable "
                "channel path 0x%x on DV",
                sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable "
                "channel path (0x%x-0x%x) on DV",
                sense->fmt.f71.md[1], sense->fmt.f71.md[2]);
        break;
    case 0x04:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable "
                "interface 0x%x on DV", sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable "
                "interfaces (0x%x-0x%x) on DV",
                sense->fmt.f71.md[1], sense->fmt.f71.md[2]);
        break;
    case 0x05:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable loader"
                " 0x%x on DV", sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable loader"
                " (0x%x-0x%x) on DV",
                sense->fmt.f71.md[1], sense->fmt.f71.md[2]);
        break;
    case 0x07:
        snprintf(service, BUFSIZE, "Repair will disable access to DV");
        break;
    case 0x08:
        if (sense->fmt.f71.mdf == 0)
            snprintf(service, BUFSIZE, "Repair will disable "
                "message display 0x%x on DV",
                sense->fmt.f71.md[1]);
        else
            snprintf(service, BUFSIZE, "Repair will disable "
                "message displays (0x%x-0x%x) on DV",
                 sense->fmt.f71.md[1], sense->fmt.f71.md[2]);
        break;
    case 0x09:
        snprintf(service, BUFSIZE, "Clean DV");
        break;
    default:
        snprintf(service, BUFSIZE, "0x%02x",
            sense->fmt.f71.smc);
    }

    dev_warn (&device->cdev->dev, "Device subsystem information: exception"
        " %s, service %s\n", exception, service);
out_nomem:
    kfree(exception);
    kfree(service);
}

/*
 * Print standard ERA Message
 */
static void
tape_3590_print_era_msg(struct tape_device *device, struct irb *irb)
{
    struct tape_3590_sense *sense;

    sense = (struct tape_3590_sense *) irb->ecw;
    if (sense->mc == 0)
        return;
    if ((sense->mc > 0) && (sense->mc < TAPE_3590_MAX_MSG)) {
        if (tape_3590_msg[sense->mc] != NULL)
            dev_warn (&device->cdev->dev, "The tape unit has "
                "issued sense message %s\n",
                tape_3590_msg[sense->mc]);
        else
            dev_warn (&device->cdev->dev, "The tape unit has "
                "issued an unknown sense message code 0x%x\n",
                sense->mc);
        return;
    }
    if (sense->mc == 0xf0) {
        /* Standard Media Information Message */
        dev_warn (&device->cdev->dev, "MIM SEV=%i, MC=%02x, ES=%x/%x, "
            "RC=%02x-%04x-%02x\n", sense->fmt.f70.sev, sense->mc,
            sense->fmt.f70.emc, sense->fmt.f70.smc,
            sense->fmt.f70.refcode, sense->fmt.f70.mid,
            sense->fmt.f70.fid);
        tape_3590_print_mim_msg_f0(device, irb);
        return;
    }
    if (sense->mc == 0xf1) {
        /* Standard I/O Subsystem Service Information Message */
        dev_warn (&device->cdev->dev, "IOSIM SEV=%i, DEVTYPE=3590/%02x,"
            " MC=%02x, ES=%x/%x, REF=0x%04x-0x%04x-0x%04x\n",
            sense->fmt.f71.sev, device->cdev->id.dev_model,
            sense->mc, sense->fmt.f71.emc, sense->fmt.f71.smc,
            sense->fmt.f71.refcode1, sense->fmt.f71.refcode2,
            sense->fmt.f71.refcode3);
        tape_3590_print_io_sim_msg_f1(device, irb);
        return;
    }
    if (sense->mc == 0xf2) {
        /* Standard Device Service Information Message */
        dev_warn (&device->cdev->dev, "DEVSIM SEV=%i, DEVTYPE=3590/%02x"
            ", MC=%02x, ES=%x/%x, REF=0x%04x-0x%04x-0x%04x\n",
            sense->fmt.f71.sev, device->cdev->id.dev_model,
            sense->mc, sense->fmt.f71.emc, sense->fmt.f71.smc,
            sense->fmt.f71.refcode1, sense->fmt.f71.refcode2,
            sense->fmt.f71.refcode3);
        tape_3590_print_dev_sim_msg_f2(device, irb);
        return;
    }
    if (sense->mc == 0xf3) {
        /* Standard Library Service Information Message */
        return;
    }
    dev_warn (&device->cdev->dev, "The tape unit has issued an unknown "
        "sense message code %x\n", sense->mc);
}

static int tape_3590_crypt_error(struct tape_device *device,
                 struct tape_request *request, struct irb *irb)
{
    u8 cu_rc;
    u16 ekm_rc2;
    char *sense;

    sense = ((struct tape_3590_sense *) irb->ecw)->fmt.data;
    cu_rc = sense[0];
    ekm_rc2 = *((u16*) &sense[10]);
    if ((cu_rc == 0) && (ekm_rc2 == 0xee31))
        /* key not defined on EKM */
        return tape_3590_erp_basic(device, request, irb, -EKEYREJECTED);
    if ((cu_rc == 1) || (cu_rc == 2))
        /* No connection to EKM */
        return tape_3590_erp_basic(device, request, irb, -ENOTCONN);

    dev_err (&device->cdev->dev, "The tape unit failed to obtain the "
        "encryption key from EKM\n");

    return tape_3590_erp_basic(device, request, irb, -ENOKEY);
}

/*
 *  3590 error Recovery routine:
 *  If possible, it tries to recover from the error. If this is not possible,
 *  inform the user about the problem.
 */
static int
tape_3590_unit_check(struct tape_device *device, struct tape_request *request,
             struct irb *irb)
{
    struct tape_3590_sense *sense;

    sense = (struct tape_3590_sense *) irb->ecw;

    DBF_EVENT(6, "Unit Check: RQC = %x\n", sense->rc_rqc);

    /*
     * First check all RC-QRCs where we want to do something special
     *   - "break":     basic error recovery is done
     *   - "goto out:": just print error message if available
     */
    switch (sense->rc_rqc) {

    case 0x1110:
        tape_3590_print_era_msg(device, irb);
        return tape_3590_erp_read_buf_log(device, request, irb);

    case 0x2011:
        tape_3590_print_era_msg(device, irb);
        return tape_3590_erp_read_alternate(device, request, irb);

    case 0x2230:
    case 0x2231:
        tape_3590_print_era_msg(device, irb);
        return tape_3590_erp_special_interrupt(device, request, irb);
    case 0x2240:
        return tape_3590_crypt_error(device, request, irb);

    case 0x3010:
        DBF_EVENT(2, "(%08x): Backward at Beginning of Partition\n",
              device->cdev_id);
        return tape_3590_erp_basic(device, request, irb, -ENOSPC);
    case 0x3012:
        DBF_EVENT(2, "(%08x): Forward at End of Partition\n",
              device->cdev_id);
        return tape_3590_erp_basic(device, request, irb, -ENOSPC);
    case 0x3020:
        DBF_EVENT(2, "(%08x): End of Data Mark\n", device->cdev_id);
        return tape_3590_erp_basic(device, request, irb, -ENOSPC);

    case 0x3122:
        DBF_EVENT(2, "(%08x): Rewind Unload initiated\n",
              device->cdev_id);
        return tape_3590_erp_basic(device, request, irb, -EIO);
    case 0x3123:
        DBF_EVENT(2, "(%08x): Rewind Unload complete\n",
              device->cdev_id);
        tape_med_state_set(device, MS_UNLOADED);
        tape_3590_schedule_work(device, TO_CRYPT_OFF);
        return tape_3590_erp_basic(device, request, irb, 0);

    case 0x4010:
        /*
         * print additional msg since default msg
         * "device intervention" is not very meaningfull
         */
        tape_med_state_set(device, MS_UNLOADED);
        tape_3590_schedule_work(device, TO_CRYPT_OFF);
        return tape_3590_erp_basic(device, request, irb, -ENOMEDIUM);
    case 0x4012:        /* Device Long Busy */
        /* XXX: Also use long busy handling here? */
        DBF_EVENT(6, "(%08x): LONG BUSY\n", device->cdev_id);
        tape_3590_print_era_msg(device, irb);
        return tape_3590_erp_basic(device, request, irb, -EBUSY);
    case 0x4014:
        DBF_EVENT(6, "(%08x): Crypto LONG BUSY\n", device->cdev_id);
        return tape_3590_erp_long_busy(device, request, irb);

    case 0x5010:
        if (sense->rac == 0xd0) {
            /* Swap */
            tape_3590_print_era_msg(device, irb);
            return tape_3590_erp_swap(device, request, irb);
        }
        if (sense->rac == 0x26) {
            /* Read Opposite */
            tape_3590_print_era_msg(device, irb);
            return tape_3590_erp_read_opposite(device, request,
                               irb);
        }
        return tape_3590_erp_basic(device, request, irb, -EIO);
    case 0x5020:
    case 0x5021:
    case 0x5022:
    case 0x5040:
    case 0x5041:
    case 0x5042:
        tape_3590_print_era_msg(device, irb);
        return tape_3590_erp_swap(device, request, irb);

    case 0x5110:
    case 0x5111:
        return tape_3590_erp_basic(device, request, irb, -EMEDIUMTYPE);

    case 0x5120:
    case 0x1120:
        tape_med_state_set(device, MS_UNLOADED);
        tape_3590_schedule_work(device, TO_CRYPT_OFF);
        return tape_3590_erp_basic(device, request, irb, -ENOMEDIUM);

    case 0x6020:
        return tape_3590_erp_basic(device, request, irb, -EMEDIUMTYPE);

    case 0x8011:
        return tape_3590_erp_basic(device, request, irb, -EPERM);
    case 0x8013:
        dev_warn (&device->cdev->dev, "A different host has privileged"
            " access to the tape unit\n");
        return tape_3590_erp_basic(device, request, irb, -EPERM);
    default:
        return tape_3590_erp_basic(device, request, irb, -EIO);
    }
}

/*
 * 3590 interrupt handler:
 */
static int
tape_3590_irq(struct tape_device *device, struct tape_request *request,
          struct irb *irb)
{
    if (request == NULL)
        return tape_3590_unsolicited_irq(device, irb);

    if ((irb->scsw.cmd.dstat & DEV_STAT_UNIT_EXCEP) &&
        (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) &&
        (request->op == TO_WRI)) {
        /* Write at end of volume */
        DBF_EVENT(2, "End of volume\n");
        return tape_3590_erp_failed(device, request, irb, -ENOSPC);
    }

    if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
        return tape_3590_unit_check(device, request, irb);

    if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
        if (irb->scsw.cmd.dstat == DEV_STAT_UNIT_EXCEP) {
            if (request->op == TO_FSB || request->op == TO_BSB)
                request->rescnt++;
            else
                DBF_EVENT(5, "Unit Exception!\n");
        }

        return tape_3590_done(device, request);
    }

    if (irb->scsw.cmd.dstat & DEV_STAT_CHN_END) {
        DBF_EVENT(2, "cannel end\n");
        return TAPE_IO_PENDING;
    }

    if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
        DBF_EVENT(2, "Unit Attention when busy..\n");
        return TAPE_IO_PENDING;
    }

    DBF_EVENT(6, "xunknownirq\n");
    tape_dump_sense_dbf(device, request, irb);
    return TAPE_IO_STOP;
}


static int tape_3590_read_dev_chars(struct tape_device *device,
                    struct tape_3590_rdc_data *rdc_data)
{
    int rc;
    struct tape_request *request;

    request = tape_alloc_request(1, sizeof(*rdc_data));
    if (IS_ERR(request))
        return PTR_ERR(request);
    request->op = TO_RDC;
    tape_ccw_end(request->cpaddr, CCW_CMD_RDC, sizeof(*rdc_data),
             request->cpdata);
    rc = tape_do_io(device, request);
    if (rc == 0)
        memcpy(rdc_data, request->cpdata, sizeof(*rdc_data));
    tape_free_request(request);
    return rc;
}

/*
 * Setup device function
 */
static int
tape_3590_setup_device(struct tape_device *device)
{
    int rc;
    struct tape_3590_disc_data *data;
    struct tape_3590_rdc_data *rdc_data;

    DBF_EVENT(6, "3590 device setup\n");
    data = kzalloc(sizeof(struct tape_3590_disc_data), GFP_KERNEL | GFP_DMA);
    if (data == NULL)
        return -ENOMEM;
    data->read_back_op = READ_PREVIOUS;
    device->discdata = data;

    rdc_data = kmalloc(sizeof(*rdc_data), GFP_KERNEL | GFP_DMA);
    if (!rdc_data) {
        rc = -ENOMEM;
        goto fail_kmalloc;
    }
    rc = tape_3590_read_dev_chars(device, rdc_data);
    if (rc) {
        DBF_LH(3, "Read device characteristics failed!\n");
        goto fail_rdc_data;
    }
    rc = tape_std_assign(device);
    if (rc)
        goto fail_rdc_data;
    if (rdc_data->data[31] == 0x13) {
        data->crypt_info.capability |= TAPE390_CRYPT_SUPPORTED_MASK;
        tape_3592_disable_crypt(device);
    } else {
        DBF_EVENT(6, "Device has NO crypto support\n");
    }
    /* Try to find out if medium is loaded */
    rc = tape_3590_sense_medium(device);
    if (rc) {
        DBF_LH(3, "3590 medium sense returned %d\n", rc);
        goto fail_rdc_data;
    }
    return 0;

fail_rdc_data:
    kfree(rdc_data);
fail_kmalloc:
    kfree(data);
    return rc;
}

/*
 * Cleanup device function
 */
static void
tape_3590_cleanup_device(struct tape_device *device)
{
    flush_workqueue(tape_3590_wq);
    tape_std_unassign(device);

    kfree(device->discdata);
    device->discdata = NULL;
}

/*
 * List of 3590 magnetic tape commands.
 */
static tape_mtop_fn tape_3590_mtop[TAPE_NR_MTOPS] = {
    [MTRESET]    = tape_std_mtreset,
    [MTFSF]      = tape_std_mtfsf,
    [MTBSF]      = tape_std_mtbsf,
    [MTFSR]      = tape_std_mtfsr,
    [MTBSR]      = tape_std_mtbsr,
    [MTWEOF]     = tape_std_mtweof,
    [MTREW]      = tape_std_mtrew,
    [MTOFFL]     = tape_std_mtoffl,
    [MTNOP]      = tape_std_mtnop,
    [MTRETEN]    = tape_std_mtreten,
    [MTBSFM]     = tape_std_mtbsfm,
    [MTFSFM]     = tape_std_mtfsfm,
    [MTEOM]      = tape_std_mteom,
    [MTERASE]    = tape_std_mterase,
    [MTRAS1]     = NULL,
    [MTRAS2]     = NULL,
    [MTRAS3]     = NULL,
    [MTSETBLK]   = tape_std_mtsetblk,
    [MTSETDENSITY]   = NULL,
    [MTSEEK]     = tape_3590_mtseek,
    [MTTELL]     = tape_3590_mttell,
    [MTSETDRVBUFFER] = NULL,
    [MTFSS]      = NULL,
    [MTBSS]      = NULL,
    [MTWSM]      = NULL,
    [MTLOCK]     = NULL,
    [MTUNLOCK]   = NULL,
    [MTLOAD]     = tape_std_mtload,
    [MTUNLOAD]   = tape_std_mtunload,
    [MTCOMPRESSION]  = tape_std_mtcompression,
    [MTSETPART]  = NULL,
    [MTMKPART]   = NULL
};

/*
 * Tape discipline structure for 3590.
 */
static struct tape_discipline tape_discipline_3590 = {
    .owner = THIS_MODULE,
    .setup_device = tape_3590_setup_device,
    .cleanup_device = tape_3590_cleanup_device,
    .process_eov = tape_std_process_eov,
    .irq = tape_3590_irq,
    .read_block = tape_std_read_block,
    .write_block = tape_std_write_block,
    .ioctl_fn = tape_3590_ioctl,
    .mtop_array = tape_3590_mtop
};

static struct ccw_device_id tape_3590_ids[] = {
    {CCW_DEVICE_DEVTYPE(0x3590, 0, 0x3590, 0), .driver_info = tape_3590},
    {CCW_DEVICE_DEVTYPE(0x3592, 0, 0x3592, 0), .driver_info = tape_3592},
    { /* end of list */ }
};

static int
tape_3590_online(struct ccw_device *cdev)
{
    return tape_generic_online(dev_get_drvdata(&cdev->dev),
                   &tape_discipline_3590);
}

static struct ccw_driver tape_3590_driver = {
    .driver = {
        .name = "tape_3590",
        .owner = THIS_MODULE,
    },
    .ids = tape_3590_ids,
    .probe = tape_generic_probe,
    .remove = tape_generic_remove,
    .set_offline = tape_generic_offline,
    .set_online = tape_3590_online,
    .freeze = tape_generic_pm_suspend,
    .int_class = IOINT_TAP,
};

/*
 * Setup discipline structure.
 */
static int
tape_3590_init(void)
{
    int rc;

    TAPE_DBF_AREA = debug_register("tape_3590", 2, 2, 4 * sizeof(long));
    debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
#ifdef DBF_LIKE_HELL
    debug_set_level(TAPE_DBF_AREA, 6);
#endif

    DBF_EVENT(3, "3590 init\n");

    tape_3590_wq = alloc_workqueue("tape_3590", 0, 0);
    if (!tape_3590_wq)
        return -ENOMEM;

    /* Register driver for 3590 tapes. */
    rc = ccw_driver_register(&tape_3590_driver);
    if (rc) {
        destroy_workqueue(tape_3590_wq);
        DBF_EVENT(3, "3590 init failed\n");
    } else
        DBF_EVENT(3, "3590 registered\n");
    return rc;
}

static void
tape_3590_exit(void)
{
    ccw_driver_unregister(&tape_3590_driver);
    destroy_workqueue(tape_3590_wq);
    debug_unregister(TAPE_DBF_AREA);
}

MODULE_DEVICE_TABLE(ccw, tape_3590_ids);
MODULE_AUTHOR("(C) 2001,2006 IBM Corporation");
MODULE_DESCRIPTION("Linux on zSeries channel attached 3590 tape device driver");
MODULE_LICENSE("GPL");

module_init(tape_3590_init);
module_exit(tape_3590_exit);