1 files changed, 1242 insertions, 0 deletions

diff --git a/drivers/s390/char/tape_core.c b/drivers/s390/char/tape_core.c
new file mode 100644
index 00000000000..e51046ab8ad
--- /dev/null
+++ b/drivers/s390/char/tape_core.c
@@ -0,0 +1,1242 @@
+/*
+ *  drivers/s390/char/tape_core.c
+ *    basic function of the tape device driver
+ *
+ *  S390 and zSeries version
+ *    Copyright (C) 2001,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Carsten Otte <cotte@de.ibm.com>
+ *               Michael Holzheu <holzheu@de.ibm.com>
+ *               Tuan Ngo-Anh <ngoanh@de.ibm.com>
+ *               Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>      // for kernel parameters
+#include <linux/kmod.h>      // for requesting modules
+#include <linux/spinlock.h>  // for locks
+#include <linux/vmalloc.h>
+#include <linux/list.h>
+
+#include <asm/types.h>       // for variable types
+
+#define TAPE_DBF_AREA   tape_core_dbf
+
+#include "tape.h"
+#include "tape_std.h"
+
+#define PRINTK_HEADER "TAPE_CORE: "
+
+static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
+static void __tape_remove_request(struct tape_device *, struct tape_request *);
+
+/*
+ * One list to contain all tape devices of all disciplines, so
+ * we can assign the devices to minor numbers of the same major
+ * The list is protected by the rwlock
+ */
+static struct list_head tape_device_list = LIST_HEAD_INIT(tape_device_list);
+static DEFINE_RWLOCK(tape_device_lock);
+
+/*
+ * Pointer to debug area.
+ */
+debug_info_t *TAPE_DBF_AREA = NULL;
+EXPORT_SYMBOL(TAPE_DBF_AREA);
+
+/*
+ * Printable strings for tape enumerations.
+ */
+const char *tape_state_verbose[TS_SIZE] =
+{
+        [TS_UNUSED]   = "UNUSED",
+        [TS_IN_USE]   = "IN_USE",
+        [TS_BLKUSE]   = "BLKUSE",
+        [TS_INIT]     = "INIT  ",
+        [TS_NOT_OPER] = "NOT_OP"
+};
+
+const char *tape_op_verbose[TO_SIZE] =
+{
+        [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
+        [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
+        [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
+        [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
+        [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
+        [TO_RFO] = "RFO",       [TO_REW] = "REW",
+        [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
+        [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
+        [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
+        [TO_READ_ATTMSG] = "RAT",
+        [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
+        [TO_UNASSIGN] = "UAS"
+};
+
+static inline int
+busid_to_int(char *bus_id)
+{
+        int     dec;
+        int     d;
+        char *  s;
+
+        for(s = bus_id, d = 0; *s != '\0' && *s != '.'; s++)
+                d = (d * 10) + (*s - '0');
+        dec = d;
+        for(s++, d = 0; *s != '\0' && *s != '.'; s++)
+                d = (d * 10) + (*s - '0');
+        dec = (dec << 8) + d;
+
+        for(s++; *s != '\0'; s++) {
+                if (*s >= '0' && *s <= '9') {
+                        d = *s - '0';
+                } else if (*s >= 'a' && *s <= 'f') {
+                        d = *s - 'a' + 10;
+                } else {
+                        d = *s - 'A' + 10;
+                }
+                dec = (dec << 4) + d;
+        }
+
+        return dec;
+}
+
+/*
+ * Some channel attached tape specific attributes.
+ *
+ * FIXME: In the future the first_minor and blocksize attribute should be
+ *        replaced by a link to the cdev tree.
+ */
+static ssize_t
+tape_medium_state_show(struct device *dev, char *buf)
+{
+        struct tape_device *tdev;
+
+        tdev = (struct tape_device *) dev->driver_data;
+        return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
+}
+
+static
+DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
+
+static ssize_t
+tape_first_minor_show(struct device *dev, char *buf)
+{
+        struct tape_device *tdev;
+
+        tdev = (struct tape_device *) dev->driver_data;
+        return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
+}
+
+static
+DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
+
+static ssize_t
+tape_state_show(struct device *dev, char *buf)
+{
+        struct tape_device *tdev;
+
+        tdev = (struct tape_device *) dev->driver_data;
+        return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
+                "OFFLINE" : tape_state_verbose[tdev->tape_state]);
+}
+
+static
+DEVICE_ATTR(state, 0444, tape_state_show, NULL);
+
+static ssize_t
+tape_operation_show(struct device *dev, char *buf)
+{
+        struct tape_device *tdev;
+        ssize_t rc;
+
+        tdev = (struct tape_device *) dev->driver_data;
+        if (tdev->first_minor < 0)
+                return scnprintf(buf, PAGE_SIZE, "N/A\n");
+
+        spin_lock_irq(get_ccwdev_lock(tdev->cdev));
+        if (list_empty(&tdev->req_queue))
+                rc = scnprintf(buf, PAGE_SIZE, "---\n");
+        else {
+                struct tape_request *req;
+
+                req = list_entry(tdev->req_queue.next, struct tape_request,
+                        list);
+                rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
+        }
+        spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
+        return rc;
+}
+
+static
+DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
+
+static ssize_t
+tape_blocksize_show(struct device *dev, char *buf)
+{
+        struct tape_device *tdev;
+
+        tdev = (struct tape_device *) dev->driver_data;
+
+        return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
+}
+
+static
+DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
+
+static struct attribute *tape_attrs[] = {
+        &dev_attr_medium_state.attr,
+        &dev_attr_first_minor.attr,
+        &dev_attr_state.attr,
+        &dev_attr_operation.attr,
+        &dev_attr_blocksize.attr,
+        NULL
+};
+
+static struct attribute_group tape_attr_group = {
+        .attrs = tape_attrs,
+};
+
+/*
+ * Tape state functions
+ */
+void
+tape_state_set(struct tape_device *device, enum tape_state newstate)
+{
+        const char *str;
+
+        if (device->tape_state == TS_NOT_OPER) {
+                DBF_EVENT(3, "ts_set err: not oper\n");
+                return;
+        }
+        DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
+        if (device->tape_state < TO_SIZE && device->tape_state >= 0)
+                str = tape_state_verbose[device->tape_state];
+        else
+                str = "UNKNOWN TS";
+        DBF_EVENT(4, "old ts:   %s\n", str);
+        if (device->tape_state < TO_SIZE && device->tape_state >=0 )
+                str = tape_state_verbose[device->tape_state];
+        else
+                str = "UNKNOWN TS";
+        DBF_EVENT(4, "%s\n", str);
+        DBF_EVENT(4, "new ts:\t\n");
+        if (newstate < TO_SIZE && newstate >= 0)
+                str = tape_state_verbose[newstate];
+        else
+                str = "UNKNOWN TS";
+        DBF_EVENT(4, "%s\n", str);
+        device->tape_state = newstate;
+        wake_up(&device->state_change_wq);
+}
+
+void
+tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
+{
+        if (device->medium_state == newstate)
+                return;
+        switch(newstate){
+        case MS_UNLOADED:
+                device->tape_generic_status |= GMT_DR_OPEN(~0);
+                PRINT_INFO("(%s): Tape is unloaded\n",
+                           device->cdev->dev.bus_id);
+                break;
+        case MS_LOADED:
+                device->tape_generic_status &= ~GMT_DR_OPEN(~0);
+                PRINT_INFO("(%s): Tape has been mounted\n",
+                           device->cdev->dev.bus_id);
+                break;
+        default:
+                // print nothing
+                break;
+        }
+        device->medium_state = newstate;
+        wake_up(&device->state_change_wq);
+}
+
+/*
+ * Stop running ccw. Has to be called with the device lock held.
+ */
+static inline int
+__tape_halt_io(struct tape_device *device, struct tape_request *request)
+{
+        int retries;
+        int rc;
+
+        /* Check if interrupt has already been processed */
+        if (request->callback == NULL)
+                return 0;
+
+        rc = 0;
+        for (retries = 0; retries < 5; retries++) {
+                rc = ccw_device_clear(device->cdev, (long) request);
+
+                if (rc == 0) {                     /* Termination successful */
+                        request->rc     = -EIO;
+                        request->status = TAPE_REQUEST_DONE;
+                        return 0;
+                }
+
+                if (rc == -ENODEV)
+                        DBF_EXCEPTION(2, "device gone, retry\n");
+                else if (rc == -EIO)
+                        DBF_EXCEPTION(2, "I/O error, retry\n");
+                else if (rc == -EBUSY)
+                        DBF_EXCEPTION(2, "device busy, retry late\n");
+                else
+                        BUG();
+        }
+
+        return rc;
+}
+
+/*
+ * Add device into the sorted list, giving it the first
+ * available minor number.
+ */
+static int
+tape_assign_minor(struct tape_device *device)
+{
+        struct tape_device *tmp;
+        int minor;
+
+        minor = 0;
+        write_lock(&tape_device_lock);
+        list_for_each_entry(tmp, &tape_device_list, node) {
+                if (minor < tmp->first_minor)
+                        break;
+                minor += TAPE_MINORS_PER_DEV;
+        }
+        if (minor >= 256) {
+                write_unlock(&tape_device_lock);
+                return -ENODEV;
+        }
+        device->first_minor = minor;
+        list_add_tail(&device->node, &tmp->node);
+        write_unlock(&tape_device_lock);
+        return 0;
+}
+
+/* remove device from the list */
+static void
+tape_remove_minor(struct tape_device *device)
+{
+        write_lock(&tape_device_lock);
+        list_del_init(&device->node);
+        device->first_minor = -1;
+        write_unlock(&tape_device_lock);
+}
+
+/*
+ * Set a device online.
+ *
+ * This function is called by the common I/O layer to move a device from the
+ * detected but offline into the online state.
+ * If we return an error (RC < 0) the device remains in the offline state. This
+ * can happen if the device is assigned somewhere else, for example.
+ */
+int
+tape_generic_online(struct tape_device *device,
+                   struct tape_discipline *discipline)
+{
+        int rc;
+
+        DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
+
+        if (device->tape_state != TS_INIT) {
+                DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
+                return -EINVAL;
+        }
+
+        /* Let the discipline have a go at the device. */
+        device->discipline = discipline;
+        if (!try_module_get(discipline->owner)) {
+                PRINT_ERR("Cannot get module. Module gone.\n");
+                return -EINVAL;
+        }
+
+        rc = discipline->setup_device(device);
+        if (rc)
+                goto out;
+        rc = tape_assign_minor(device);
+        if (rc)
+                goto out_discipline;
+
+        rc = tapechar_setup_device(device);
+        if (rc)
+                goto out_minor;
+        rc = tapeblock_setup_device(device);
+        if (rc)
+                goto out_char;
+
+        tape_state_set(device, TS_UNUSED);
+
+        DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
+
+        return 0;
+
+out_char:
+        tapechar_cleanup_device(device);
+out_discipline:
+        device->discipline->cleanup_device(device);
+        device->discipline = NULL;
+out_minor:
+        tape_remove_minor(device);
+out:
+        module_put(discipline->owner);
+        return rc;
+}
+
+static inline void
+tape_cleanup_device(struct tape_device *device)
+{
+        tapeblock_cleanup_device(device);
+        tapechar_cleanup_device(device);
+        device->discipline->cleanup_device(device);
+        module_put(device->discipline->owner);
+        tape_remove_minor(device);
+        tape_med_state_set(device, MS_UNKNOWN);
+}
+
+/*
+ * Set device offline.
+ *
+ * Called by the common I/O layer if the drive should set offline on user
+ * request. We may prevent this by returning an error.
+ * Manual offline is only allowed while the drive is not in use.
+ */
+int
+tape_generic_offline(struct tape_device *device)
+{
+        if (!device) {
+                PRINT_ERR("tape_generic_offline: no such device\n");
+                return -ENODEV;
+        }
+
+        DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
+                device->cdev_id, device);
+
+        spin_lock_irq(get_ccwdev_lock(device->cdev));
+        switch (device->tape_state) {
+                case TS_INIT:
+                case TS_NOT_OPER:
+                        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+                        break;
+                case TS_UNUSED:
+                        tape_state_set(device, TS_INIT);
+                        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+                        tape_cleanup_device(device);
+                        break;
+                default:
+                        DBF_EVENT(3, "(%08x): Set offline failed "
+                                "- drive in use.\n",
+                                device->cdev_id);
+                        PRINT_WARN("(%s): Set offline failed "
+                                "- drive in use.\n",
+                                device->cdev->dev.bus_id);
+                        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+                        return -EBUSY;
+        }
+
+        DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
+        return 0;
+}
+
+/*
+ * Allocate memory for a new device structure.
+ */
+static struct tape_device *
+tape_alloc_device(void)
+{
+        struct tape_device *device;
+
+        device = (struct tape_device *)
+                kmalloc(sizeof(struct tape_device), GFP_KERNEL);
+        if (device == NULL) {
+                DBF_EXCEPTION(2, "ti:no mem\n");
+                PRINT_INFO ("can't allocate memory for "
+                            "tape info structure\n");
+                return ERR_PTR(-ENOMEM);
+        }
+        memset(device, 0, sizeof(struct tape_device));
+        device->modeset_byte = (char *) kmalloc(1, GFP_KERNEL | GFP_DMA);
+        if (device->modeset_byte == NULL) {
+                DBF_EXCEPTION(2, "ti:no mem\n");
+                PRINT_INFO("can't allocate memory for modeset byte\n");
+                kfree(device);
+                return ERR_PTR(-ENOMEM);
+        }
+        INIT_LIST_HEAD(&device->req_queue);
+        INIT_LIST_HEAD(&device->node);
+        init_waitqueue_head(&device->state_change_wq);
+        device->tape_state = TS_INIT;
+        device->medium_state = MS_UNKNOWN;
+        *device->modeset_byte = 0;
+        device->first_minor = -1;
+        atomic_set(&device->ref_count, 1);
+
+        return device;
+}
+
+/*
+ * Get a reference to an existing device structure. This will automatically
+ * increment the reference count.
+ */
+struct tape_device *
+tape_get_device_reference(struct tape_device *device)
+{
+        DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
+                atomic_inc_return(&device->ref_count));
+
+        return device;
+}
+
+/*
+ * Decrease the reference counter of a devices structure. If the
+ * reference counter reaches zero free the device structure.
+ * The function returns a NULL pointer to be used by the caller
+ * for clearing reference pointers.
+ */
+struct tape_device *
+tape_put_device(struct tape_device *device)
+{
+        int remain;
+
+        remain = atomic_dec_return(&device->ref_count);
+        if (remain > 0) {
+                DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
+        } else {
+                if (remain < 0) {
+                        DBF_EVENT(4, "put device without reference\n");
+                        PRINT_ERR("put device without reference\n");
+                } else {
+                        DBF_EVENT(4, "tape_free_device(%p)\n", device);
+                        kfree(device->modeset_byte);
+                        kfree(device);
+                }
+        }
+
+        return NULL;                    
+}
+
+/*
+ * Find tape device by a device index.
+ */
+struct tape_device *
+tape_get_device(int devindex)
+{
+        struct tape_device *device, *tmp;
+
+        device = ERR_PTR(-ENODEV);
+        read_lock(&tape_device_lock);
+        list_for_each_entry(tmp, &tape_device_list, node) {
+                if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
+                        device = tape_get_device_reference(tmp);
+                        break;
+                }
+        }
+        read_unlock(&tape_device_lock);
+        return device;
+}
+
+/*
+ * Driverfs tape probe function.
+ */
+int
+tape_generic_probe(struct ccw_device *cdev)
+{
+        struct tape_device *device;
+
+        device = tape_alloc_device();
+        if (IS_ERR(device))
+                return -ENODEV;
+        PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
+        cdev->dev.driver_data = device;
+        device->cdev = cdev;
+        device->cdev_id = busid_to_int(cdev->dev.bus_id);
+        cdev->handler = __tape_do_irq;
+
+        ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
+        sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
+
+        return 0;
+}
+
+static inline void
+__tape_discard_requests(struct tape_device *device)
+{
+        struct tape_request *   request;
+        struct list_head *      l, *n;
+
+        list_for_each_safe(l, n, &device->req_queue) {
+                request = list_entry(l, struct tape_request, list);
+                if (request->status == TAPE_REQUEST_IN_IO)
+                        request->status = TAPE_REQUEST_DONE;
+                list_del(&request->list);
+
+                /* Decrease ref_count for removed request. */
+                request->device = tape_put_device(device);
+                request->rc = -EIO;
+                if (request->callback != NULL)
+                        request->callback(request, request->callback_data);
+        }
+}
+
+/*
+ * Driverfs tape remove function.
+ *
+ * This function is called whenever the common I/O layer detects the device
+ * gone. This can happen at any time and we cannot refuse.
+ */
+void
+tape_generic_remove(struct ccw_device *cdev)
+{
+        struct tape_device *    device;
+
+        device = cdev->dev.driver_data;
+        if (!device) {
+                PRINT_ERR("No device pointer in tape_generic_remove!\n");
+                return;
+        }
+        DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
+
+        spin_lock_irq(get_ccwdev_lock(device->cdev));
+        switch (device->tape_state) {
+                case TS_INIT:
+                        tape_state_set(device, TS_NOT_OPER);
+                case TS_NOT_OPER:
+                        /*
+                         * Nothing to do.
+                         */
+                        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+                        break;
+                case TS_UNUSED:
+                        /*
+                         * Need only to release the device.
+                         */
+                        tape_state_set(device, TS_NOT_OPER);
+                        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+                        tape_cleanup_device(device);
+                        break;
+                default:
+                        /*
+                         * There may be requests on the queue. We will not get
+                         * an interrupt for a request that was running. So we
+                         * just post them all as I/O errors.
+                         */
+                        DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
+                                device->cdev_id);
+                        PRINT_WARN("(%s): Drive in use vanished - "
+                                "expect trouble!\n",
+                                device->cdev->dev.bus_id);
+                        PRINT_WARN("State was %i\n", device->tape_state);
+                        tape_state_set(device, TS_NOT_OPER);
+                        __tape_discard_requests(device);
+                        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+                        tape_cleanup_device(device);
+        }
+
+        if (cdev->dev.driver_data != NULL) {
+                sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
+                cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
+        }
+}
+
+/*
+ * Allocate a new tape ccw request
+ */
+struct tape_request *
+tape_alloc_request(int cplength, int datasize)
+{
+        struct tape_request *request;
+
+        if (datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
+                BUG();
+
+        DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
+
+        request = (struct tape_request *) kmalloc(sizeof(struct tape_request),
+                                                  GFP_KERNEL);
+        if (request == NULL) {
+                DBF_EXCEPTION(1, "cqra nomem\n");
+                return ERR_PTR(-ENOMEM);
+        }
+        memset(request, 0, sizeof(struct tape_request));
+        /* allocate channel program */
+        if (cplength > 0) {
+                request->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
+                                          GFP_ATOMIC | GFP_DMA);
+                if (request->cpaddr == NULL) {
+                        DBF_EXCEPTION(1, "cqra nomem\n");
+                        kfree(request);
+                        return ERR_PTR(-ENOMEM);
+                }
+                memset(request->cpaddr, 0, cplength*sizeof(struct ccw1));
+        }
+        /* alloc small kernel buffer */
+        if (datasize > 0) {
+                request->cpdata = kmalloc(datasize, GFP_KERNEL | GFP_DMA);
+                if (request->cpdata == NULL) {
+                        DBF_EXCEPTION(1, "cqra nomem\n");
+                        if (request->cpaddr != NULL)
+                                kfree(request->cpaddr);
+                        kfree(request);
+                        return ERR_PTR(-ENOMEM);
+                }
+                memset(request->cpdata, 0, datasize);
+        }
+        DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
+                request->cpdata);
+
+        return request;
+}
+
+/*
+ * Free tape ccw request
+ */
+void
+tape_free_request (struct tape_request * request)
+{
+        DBF_LH(6, "Free request %p\n", request);
+
+        if (request->device != NULL) {
+                request->device = tape_put_device(request->device);
+        }
+        if (request->cpdata != NULL)
+                kfree(request->cpdata);
+        if (request->cpaddr != NULL)
+                kfree(request->cpaddr);
+        kfree(request);
+}
+
+static inline void
+__tape_do_io_list(struct tape_device *device)
+{
+        struct list_head *l, *n;
+        struct tape_request *request;
+        int rc;
+
+        DBF_LH(6, "__tape_do_io_list(%p)\n", device);
+        /*
+         * Try to start each request on request queue until one is
+         * started successful.
+         */
+        list_for_each_safe(l, n, &device->req_queue) {
+                request = list_entry(l, struct tape_request, list);
+#ifdef CONFIG_S390_TAPE_BLOCK
+                if (request->op == TO_BLOCK)
+                        device->discipline->check_locate(device, request);
+#endif
+                rc = ccw_device_start(device->cdev, request->cpaddr,
+                                      (unsigned long) request, 0x00,
+                                      request->options);
+                if (rc == 0) {
+                        request->status = TAPE_REQUEST_IN_IO;
+                        break;
+                }
+                /* Start failed. Remove request and indicate failure. */
+                DBF_EVENT(1, "tape: DOIO failed with er = %i\n", rc);
+
+                /* Set ending status and do callback. */
+                request->rc = rc;
+                request->status = TAPE_REQUEST_DONE;
+                __tape_remove_request(device, request);
+        }
+}
+
+static void
+__tape_remove_request(struct tape_device *device, struct tape_request *request)
+{
+        /* Remove from request queue. */
+        list_del(&request->list);
+
+        /* Do callback. */
+        if (request->callback != NULL)
+                request->callback(request, request->callback_data);
+
+        /* Start next request. */
+        if (!list_empty(&device->req_queue))
+                __tape_do_io_list(device);
+}
+
+/*
+ * Write sense data to console/dbf
+ */
+void
+tape_dump_sense(struct tape_device* device, struct tape_request *request,
+                struct irb *irb)
+{
+        unsigned int *sptr;
+
+        PRINT_INFO("-------------------------------------------------\n");
+        PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
+                   irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
+        PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
+        if (request != NULL)
+                PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
+
+        sptr = (unsigned int *) irb->ecw;
+        PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
+                   sptr[0], sptr[1], sptr[2], sptr[3]);
+        PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
+                   sptr[4], sptr[5], sptr[6], sptr[7]);
+        PRINT_INFO("--------------------------------------------------\n");
+}
+
+/*
+ * Write sense data to dbf
+ */
+void
+tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
+                    struct irb *irb)
+{
+        unsigned int *sptr;
+        const char* op;
+
+        if (request != NULL)
+                op = tape_op_verbose[request->op];
+        else
+                op = "---";
+        DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
+                  irb->scsw.dstat,irb->scsw.cstat);
+        DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
+        sptr = (unsigned int *) irb->ecw;
+        DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
+        DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
+        DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
+        DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
+}
+
+/*
+ * I/O helper function. Adds the request to the request queue
+ * and starts it if the tape is idle. Has to be called with
+ * the device lock held.
+ */
+static inline int
+__tape_do_io(struct tape_device *device, struct tape_request *request)
+{
+        int rc;
+
+        switch (request->op) {
+                case TO_MSEN:
+                case TO_ASSIGN:
+                case TO_UNASSIGN:
+                case TO_READ_ATTMSG:
+                        if (device->tape_state == TS_INIT)
+                                break;
+                        if (device->tape_state == TS_UNUSED)
+                                break;
+                default:
+                        if (device->tape_state == TS_BLKUSE)
+                                break;
+                        if (device->tape_state != TS_IN_USE)
+                                return -ENODEV;
+        }
+
+        /* Increase use count of device for the added request. */
+        request->device = tape_get_device_reference(device);
+
+        if (list_empty(&device->req_queue)) {
+                /* No other requests are on the queue. Start this one. */
+#ifdef CONFIG_S390_TAPE_BLOCK
+                if (request->op == TO_BLOCK)
+                        device->discipline->check_locate(device, request);
+#endif
+                rc = ccw_device_start(device->cdev, request->cpaddr,
+                                      (unsigned long) request, 0x00,
+                                      request->options);
+                if (rc) {
+                        DBF_EVENT(1, "tape: DOIO failed with rc = %i\n", rc);
+                        return rc;
+                }
+                DBF_LH(5, "Request %p added for execution.\n", request);
+                list_add(&request->list, &device->req_queue);
+                request->status = TAPE_REQUEST_IN_IO;
+        } else {
+                DBF_LH(5, "Request %p add to queue.\n", request);
+                list_add_tail(&request->list, &device->req_queue);
+                request->status = TAPE_REQUEST_QUEUED;
+        }
+        return 0;
+}
+
+/*
+ * Add the request to the request queue, try to start it if the
+ * tape is idle. Return without waiting for end of i/o.
+ */
+int
+tape_do_io_async(struct tape_device *device, struct tape_request *request)
+{
+        int rc;
+
+        DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
+
+        spin_lock_irq(get_ccwdev_lock(device->cdev));
+        /* Add request to request queue and try to start it. */
+        rc = __tape_do_io(device, request);
+        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+        return rc;
+}
+
+/*
+ * tape_do_io/__tape_wake_up
+ * Add the request to the request queue, try to start it if the
+ * tape is idle and wait uninterruptible for its completion.
+ */
+static void
+__tape_wake_up(struct tape_request *request, void *data)
+{
+        request->callback = NULL;
+        wake_up((wait_queue_head_t *) data);
+}
+
+int
+tape_do_io(struct tape_device *device, struct tape_request *request)
+{
+        wait_queue_head_t wq;
+        int rc;
+
+        init_waitqueue_head(&wq);
+        spin_lock_irq(get_ccwdev_lock(device->cdev));
+        /* Setup callback */
+        request->callback = __tape_wake_up;
+        request->callback_data = &wq;
+        /* Add request to request queue and try to start it. */
+        rc = __tape_do_io(device, request);
+        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+        if (rc)
+                return rc;
+        /* Request added to the queue. Wait for its completion. */
+        wait_event(wq, (request->callback == NULL));
+        /* Get rc from request */
+        return request->rc;
+}
+
+/*
+ * tape_do_io_interruptible/__tape_wake_up_interruptible
+ * Add the request to the request queue, try to start it if the
+ * tape is idle and wait uninterruptible for its completion.
+ */
+static void
+__tape_wake_up_interruptible(struct tape_request *request, void *data)
+{
+        request->callback = NULL;
+        wake_up_interruptible((wait_queue_head_t *) data);
+}
+
+int
+tape_do_io_interruptible(struct tape_device *device,
+                         struct tape_request *request)
+{
+        wait_queue_head_t wq;
+        int rc;
+
+        init_waitqueue_head(&wq);
+        spin_lock_irq(get_ccwdev_lock(device->cdev));
+        /* Setup callback */
+        request->callback = __tape_wake_up_interruptible;
+        request->callback_data = &wq;
+        rc = __tape_do_io(device, request);
+        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+        if (rc)
+                return rc;
+        /* Request added to the queue. Wait for its completion. */
+        rc = wait_event_interruptible(wq, (request->callback == NULL));
+        if (rc != -ERESTARTSYS)
+                /* Request finished normally. */
+                return request->rc;
+        /* Interrupted by a signal. We have to stop the current request. */
+        spin_lock_irq(get_ccwdev_lock(device->cdev));
+        rc = __tape_halt_io(device, request);
+        if (rc == 0) {
+                DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
+                rc = -ERESTARTSYS;
+        }
+        spin_unlock_irq(get_ccwdev_lock(device->cdev));
+        return rc;
+}
+
+/*
+ * Handle requests that return an i/o error in the irb.
+ */
+static inline void
+tape_handle_killed_request(
+        struct tape_device *device,
+        struct tape_request *request)
+{
+        if(request != NULL) {
+                /* Set ending status. FIXME: Should the request be retried? */
+                request->rc = -EIO;
+                request->status = TAPE_REQUEST_DONE;
+                __tape_remove_request(device, request);
+        } else {
+                __tape_do_io_list(device);
+        }
+}
+
+/*
+ * Tape interrupt routine, called from the ccw_device layer
+ */
+static void
+__tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
+{
+        struct tape_device *device;
+        struct tape_request *request;
+        int final;
+        int rc;
+
+        device = (struct tape_device *) cdev->dev.driver_data;
+        if (device == NULL) {
+                PRINT_ERR("could not get device structure for %s "
+                          "in interrupt\n", cdev->dev.bus_id);
+                return;
+        }
+        request = (struct tape_request *) intparm;
+
+        DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
+
+        /* On special conditions irb is an error pointer */
+        if (IS_ERR(irb)) {
+                switch (PTR_ERR(irb)) {
+                        case -ETIMEDOUT:
+                                PRINT_WARN("(%s): Request timed out\n",
+                                        cdev->dev.bus_id);
+                        case -EIO:
+                                tape_handle_killed_request(device, request);
+                                break;
+                        default:
+                                PRINT_ERR("(%s): Unexpected i/o error %li\n",
+                                        cdev->dev.bus_id,
+                                        PTR_ERR(irb));
+                }
+                return;
+        }
+
+        /* May be an unsolicited irq */
+        if(request != NULL)
+                request->rescnt = irb->scsw.count;
+
+        if (irb->scsw.dstat != 0x0c) {
+                /* Set the 'ONLINE' flag depending on sense byte 1 */
+                if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
+                        device->tape_generic_status |= GMT_ONLINE(~0);
+                else
+                        device->tape_generic_status &= ~GMT_ONLINE(~0);
+
+                /*
+                 * Any request that does not come back with channel end
+                 * and device end is unusual. Log the sense data.
+                 */
+                DBF_EVENT(3,"-- Tape Interrupthandler --\n");
+                tape_dump_sense_dbf(device, request, irb);
+        } else {
+                /* Upon normal completion the device _is_ online */
+                device->tape_generic_status |= GMT_ONLINE(~0);
+        }
+        if (device->tape_state == TS_NOT_OPER) {
+                DBF_EVENT(6, "tape:device is not operational\n");
+                return;
+        }
+
+        /*
+         * Request that were canceled still come back with an interrupt.
+         * To detect these request the state will be set to TAPE_REQUEST_DONE.
+         */
+        if(request != NULL && request->status == TAPE_REQUEST_DONE) {
+                __tape_remove_request(device, request);
+                return;
+        }
+
+        rc = device->discipline->irq(device, request, irb);
+        /*
+         * rc < 0 : request finished unsuccessfully.
+         * rc == TAPE_IO_SUCCESS: request finished successfully.
+         * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
+         * rc == TAPE_IO_RETRY: request finished but needs another go.
+         * rc == TAPE_IO_STOP: request needs to get terminated.
+         */
+        final = 0;
+        switch (rc) {
+        case TAPE_IO_SUCCESS:
+                /* Upon normal completion the device _is_ online */
+                device->tape_generic_status |= GMT_ONLINE(~0);
+                final = 1;
+                break;
+        case TAPE_IO_PENDING:
+                break;
+        case TAPE_IO_RETRY:
+#ifdef CONFIG_S390_TAPE_BLOCK
+                if (request->op == TO_BLOCK)
+                        device->discipline->check_locate(device, request);
+#endif
+                rc = ccw_device_start(cdev, request->cpaddr,
+                                      (unsigned long) request, 0x00,
+                                      request->options);
+                if (rc) {
+                        DBF_EVENT(1, "tape: DOIO failed with er = %i\n", rc);
+                        final = 1;
+                }
+                break;
+        case TAPE_IO_STOP:
+                __tape_halt_io(device, request);
+                break;
+        default:
+                if (rc > 0) {
+                        DBF_EVENT(6, "xunknownrc\n");
+                        PRINT_ERR("Invalid return code from discipline "
+                                  "interrupt function.\n");
+                        rc = -EIO;
+                }
+                final = 1;
+                break;
+        }
+        if (final) {
+                /* May be an unsolicited irq */
+                if(request != NULL) {
+                        /* Set ending status. */
+                        request->rc = rc;
+                        request->status = TAPE_REQUEST_DONE;
+                        __tape_remove_request(device, request);
+                } else {
+                        __tape_do_io_list(device);
+                }
+        }
+}
+
+/*
+ * Tape device open function used by tape_char & tape_block frontends.
+ */
+int
+tape_open(struct tape_device *device)
+{
+        int rc;
+
+        spin_lock(get_ccwdev_lock(device->cdev));
+        if (device->tape_state == TS_NOT_OPER) {
+                DBF_EVENT(6, "TAPE:nodev\n");
+                rc = -ENODEV;
+        } else if (device->tape_state == TS_IN_USE) {
+                DBF_EVENT(6, "TAPE:dbusy\n");
+                rc = -EBUSY;
+        } else if (device->tape_state == TS_BLKUSE) {
+                DBF_EVENT(6, "TAPE:dbusy\n");
+                rc = -EBUSY;
+        } else if (device->discipline != NULL &&
+                   !try_module_get(device->discipline->owner)) {
+                DBF_EVENT(6, "TAPE:nodisc\n");
+                rc = -ENODEV;
+        } else {
+                tape_state_set(device, TS_IN_USE);
+                rc = 0;
+        }
+        spin_unlock(get_ccwdev_lock(device->cdev));
+        return rc;
+}
+
+/*
+ * Tape device release function used by tape_char & tape_block frontends.
+ */
+int
+tape_release(struct tape_device *device)
+{
+        spin_lock(get_ccwdev_lock(device->cdev));
+        if (device->tape_state == TS_IN_USE)
+                tape_state_set(device, TS_UNUSED);
+        module_put(device->discipline->owner);
+        spin_unlock(get_ccwdev_lock(device->cdev));
+        return 0;
+}
+
+/*
+ * Execute a magnetic tape command a number of times.
+ */
+int
+tape_mtop(struct tape_device *device, int mt_op, int mt_count)
+{
+        tape_mtop_fn fn;
+        int rc;
+
+        DBF_EVENT(6, "TAPE:mtio\n");
+        DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
+        DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
+
+        if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
+                return -EINVAL;
+        fn = device->discipline->mtop_array[mt_op];
+        if (fn == NULL)
+                return -EINVAL;
+
+        /* We assume that the backends can handle count up to 500. */
+        if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
+            mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
+                rc = 0;
+                for (; mt_count > 500; mt_count -= 500)
+                        if ((rc = fn(device, 500)) != 0)
+                                break;
+                if (rc == 0)
+                        rc = fn(device, mt_count);
+        } else
+                rc = fn(device, mt_count);
+        return rc;
+
+}
+
+/*
+ * Tape init function.
+ */
+static int
+tape_init (void)
+{
+        TAPE_DBF_AREA = debug_register ( "tape", 1, 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, "tape init: ($Revision: 1.51 $)\n");
+        tape_proc_init();
+        tapechar_init ();
+        tapeblock_init ();
+        return 0;
+}
+
+/*
+ * Tape exit function.
+ */
+static void
+tape_exit(void)
+{
+        DBF_EVENT(6, "tape exit\n");
+
+        /* Get rid of the frontends */
+        tapechar_exit();
+        tapeblock_exit();
+        tape_proc_cleanup();
+        debug_unregister (TAPE_DBF_AREA);
+}
+
+MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
+              "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
+MODULE_DESCRIPTION("Linux on zSeries channel attached "
+                   "tape device driver ($Revision: 1.51 $)");
+MODULE_LICENSE("GPL");
+
+module_init(tape_init);
+module_exit(tape_exit);
+
+EXPORT_SYMBOL(tape_generic_remove);
+EXPORT_SYMBOL(tape_generic_probe);
+EXPORT_SYMBOL(tape_generic_online);
+EXPORT_SYMBOL(tape_generic_offline);
+EXPORT_SYMBOL(tape_put_device);
+EXPORT_SYMBOL(tape_get_device_reference);
+EXPORT_SYMBOL(tape_state_verbose);
+EXPORT_SYMBOL(tape_op_verbose);
+EXPORT_SYMBOL(tape_state_set);
+EXPORT_SYMBOL(tape_med_state_set);
+EXPORT_SYMBOL(tape_alloc_request);
+EXPORT_SYMBOL(tape_free_request);
+EXPORT_SYMBOL(tape_dump_sense);
+EXPORT_SYMBOL(tape_dump_sense_dbf);
+EXPORT_SYMBOL(tape_do_io);
+EXPORT_SYMBOL(tape_do_io_async);
+EXPORT_SYMBOL(tape_do_io_interruptible);
+EXPORT_SYMBOL(tape_mtop);