--- /dev/null
+/*
+ * basic function of the tape device driver
+ *
+ * S390 and zSeries version
+ * Copyright IBM Corp. 2001, 2009
+ * 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>
+ * Stefan Bader <shbader@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "tape"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#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 <linux/slab.h>
+
+#include <asm/types.h> // for variable types
+
+#define TAPE_DBF_AREA tape_core_dbf
+
+#include "tape.h"
+#include "tape_std.h"
+
+#define LONG_BUSY_TIMEOUT 180 /* seconds */
+
+static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
+static void tape_delayed_next_request(struct work_struct *);
+static void tape_long_busy_timeout(unsigned long data);
+
+/*
+ * 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 LIST_HEAD(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", [TO_CRYPT_ON] = "CON",
+ [TO_CRYPT_OFF] = "COF", [TO_KEKL_SET] = "KLS",
+ [TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
+};
+
+static int devid_to_int(struct ccw_dev_id *dev_id)
+{
+ return dev_id->devno + (dev_id->ssid << 16);
+}
+
+/*
+ * 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, struct device_attribute *attr, char *buf)
+{
+ struct tape_device *tdev;
+
+ tdev = dev_get_drvdata(dev);
+ 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, struct device_attribute *attr, char *buf)
+{
+ struct tape_device *tdev;
+
+ tdev = dev_get_drvdata(dev);
+ 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, struct device_attribute *attr, char *buf)
+{
+ struct tape_device *tdev;
+
+ tdev = dev_get_drvdata(dev);
+ 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, struct device_attribute *attr, char *buf)
+{
+ struct tape_device *tdev;
+ ssize_t rc;
+
+ tdev = dev_get_drvdata(dev);
+ 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, struct device_attribute *attr, char *buf)
+{
+ struct tape_device *tdev;
+
+ tdev = dev_get_drvdata(dev);
+
+ 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);
+ DBF_EVENT(4, "old ts:\t\n");
+ if (device->tape_state < TS_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 < TS_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);
+}
+
+struct tape_med_state_work_data {
+ struct tape_device *device;
+ enum tape_medium_state state;
+ struct work_struct work;
+};
+
+static void
+tape_med_state_work_handler(struct work_struct *work)
+{
+ static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
+ static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
+ struct tape_med_state_work_data *p =
+ container_of(work, struct tape_med_state_work_data, work);
+ struct tape_device *device = p->device;
+ char *envp[] = { NULL, NULL };
+
+ switch (p->state) {
+ case MS_UNLOADED:
+ pr_info("%s: The tape cartridge has been successfully "
+ "unloaded\n", dev_name(&device->cdev->dev));
+ envp[0] = env_state_unloaded;
+ kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
+ break;
+ case MS_LOADED:
+ pr_info("%s: A tape cartridge has been mounted\n",
+ dev_name(&device->cdev->dev));
+ envp[0] = env_state_loaded;
+ kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
+ break;
+ default:
+ break;
+ }
+ tape_put_device(device);
+ kfree(p);
+}
+
+static void
+tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
+{
+ struct tape_med_state_work_data *p;
+
+ p = kzalloc(sizeof(*p), GFP_ATOMIC);
+ if (p) {
+ INIT_WORK(&p->work, tape_med_state_work_handler);
+ p->device = tape_get_device(device);
+ p->state = state;
+ schedule_work(&p->work);
+ }
+}
+
+void
+tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
+{
+ enum tape_medium_state oldstate;
+
+ oldstate = device->medium_state;
+ if (oldstate == newstate)
+ return;
+ device->medium_state = newstate;
+ switch(newstate){
+ case MS_UNLOADED:
+ device->tape_generic_status |= GMT_DR_OPEN(~0);
+ if (oldstate == MS_LOADED)
+ tape_med_state_work(device, MS_UNLOADED);
+ break;
+ case MS_LOADED:
+ device->tape_generic_status &= ~GMT_DR_OPEN(~0);
+ if (oldstate == MS_UNLOADED)
+ tape_med_state_work(device, MS_LOADED);
+ break;
+ default:
+ break;
+ }
+ wake_up(&device->state_change_wq);
+}
+
+/*
+ * Stop running ccw. Has to be called with the device lock held.
+ */
+static int
+__tape_cancel_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);
+
+ switch (rc) {
+ case 0:
+ request->status = TAPE_REQUEST_DONE;
+ return 0;
+ case -EBUSY:
+ request->status = TAPE_REQUEST_CANCEL;
+ schedule_delayed_work(&device->tape_dnr, 0);
+ return 0;
+ case -ENODEV:
+ DBF_EXCEPTION(2, "device gone, retry\n");
+ break;
+ case -EIO:
+ DBF_EXCEPTION(2, "I/O error, retry\n");
+ break;
+ default:
+ 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;
+ }
+
+ init_timer(&device->lb_timeout);
+ device->lb_timeout.function = tape_long_busy_timeout;
+
+ /* Let the discipline have a go at the device. */
+ device->discipline = discipline;
+ if (!try_module_get(discipline->owner)) {
+ 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;
+
+ tape_state_set(device, TS_UNUSED);
+
+ DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
+
+ return 0;
+
+out_minor:
+ tape_remove_minor(device);
+out_discipline:
+ device->discipline->cleanup_device(device);
+ device->discipline = NULL;
+out:
+ module_put(discipline->owner);
+ return rc;
+}
+
+static void
+tape_cleanup_device(struct tape_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);
+}
+
+/*
+ * Suspend device.
+ *
+ * Called by the common I/O layer if the drive should be suspended on user
+ * request. We refuse to suspend if the device is loaded or in use for the
+ * following reason:
+ * While the Linux guest is suspended, it might be logged off which causes
+ * devices to be detached. Tape devices are automatically rewound and unloaded
+ * during DETACH processing (unless the tape device was attached with the
+ * NOASSIGN or MULTIUSER option). After rewind/unload, there is no way to
+ * resume the original state of the tape device, since we would need to
+ * manually re-load the cartridge which was active at suspend time.
+ */
+int tape_generic_pm_suspend(struct ccw_device *cdev)
+{
+ struct tape_device *device;
+
+ device = dev_get_drvdata(&cdev->dev);
+ if (!device) {
+ return -ENODEV;
+ }
+
+ DBF_LH(3, "(%08x): tape_generic_pm_suspend(%p)\n",
+ device->cdev_id, device);
+
+ if (device->medium_state != MS_UNLOADED) {
+ pr_err("A cartridge is loaded in tape device %s, "
+ "refusing to suspend\n", dev_name(&cdev->dev));
+ return -EBUSY;
+ }
+
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ switch (device->tape_state) {
+ case TS_INIT:
+ case TS_NOT_OPER:
+ case TS_UNUSED:
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ break;
+ default:
+ pr_err("Tape device %s is busy, refusing to "
+ "suspend\n", dev_name(&cdev->dev));
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ return -EBUSY;
+ }
+
+ DBF_LH(3, "(%08x): Drive suspended.\n", device->cdev_id);
+ return 0;
+}
+
+/*
+ * 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 ccw_device *cdev)
+{
+ struct tape_device *device;
+
+ device = dev_get_drvdata(&cdev->dev);
+ if (!device) {
+ 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);
+ 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 = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
+ if (device == NULL) {
+ DBF_EXCEPTION(2, "ti:no mem\n");
+ return ERR_PTR(-ENOMEM);
+ }
+ device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
+ if (device->modeset_byte == NULL) {
+ DBF_EXCEPTION(2, "ti:no mem\n");
+ kfree(device);
+ return ERR_PTR(-ENOMEM);
+ }
+ mutex_init(&device->mutex);
+ INIT_LIST_HEAD(&device->req_queue);
+ INIT_LIST_HEAD(&device->node);
+ init_waitqueue_head(&device->state_change_wq);
+ init_waitqueue_head(&device->wait_queue);
+ device->tape_state = TS_INIT;
+ device->medium_state = MS_UNKNOWN;
+ *device->modeset_byte = 0;
+ device->first_minor = -1;
+ atomic_set(&device->ref_count, 1);
+ INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
+
+ return device;
+}
+
+/*
+ * Get a reference to an existing device structure. This will automatically
+ * increment the reference count.
+ */
+struct tape_device *
+tape_get_device(struct tape_device *device)
+{
+ int count;
+
+ count = atomic_inc_return(&device->ref_count);
+ DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, 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.
+ */
+void
+tape_put_device(struct tape_device *device)
+{
+ int count;
+
+ count = atomic_dec_return(&device->ref_count);
+ DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
+ BUG_ON(count < 0);
+ if (count == 0) {
+ kfree(device->modeset_byte);
+ kfree(device);
+ }
+}
+
+/*
+ * Find tape device by a device index.
+ */
+struct tape_device *
+tape_find_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(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;
+ int ret;
+ struct ccw_dev_id dev_id;
+
+ device = tape_alloc_device();
+ if (IS_ERR(device))
+ return -ENODEV;
+ ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
+ CCWDEV_DO_MULTIPATH);
+ ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
+ if (ret) {
+ tape_put_device(device);
+ return ret;
+ }
+ dev_set_drvdata(&cdev->dev, device);
+ cdev->handler = __tape_do_irq;
+ device->cdev = cdev;
+ ccw_device_get_id(cdev, &dev_id);
+ device->cdev_id = devid_to_int(&dev_id);
+ return ret;
+}
+
+static 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 = NULL;
+ 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 = dev_get_drvdata(&cdev->dev);
+ if (!device) {
+ 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);
+ pr_warning("%s: A tape unit was detached while in "
+ "use\n", dev_name(&device->cdev->dev));
+ tape_state_set(device, TS_NOT_OPER);
+ __tape_discard_requests(device);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ tape_cleanup_device(device);
+ }
+
+ device = dev_get_drvdata(&cdev->dev);
+ if (device) {
+ sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
+ dev_set_drvdata(&cdev->dev, NULL);
+ tape_put_device(device);
+ }
+}
+
+/*
+ * Allocate a new tape ccw request
+ */
+struct tape_request *
+tape_alloc_request(int cplength, int datasize)
+{
+ struct tape_request *request;
+
+ BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
+
+ DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
+
+ request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
+ if (request == NULL) {
+ DBF_EXCEPTION(1, "cqra nomem\n");
+ return ERR_PTR(-ENOMEM);
+ }
+ /* allocate channel program */
+ if (cplength > 0) {
+ request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
+ GFP_ATOMIC | GFP_DMA);
+ if (request->cpaddr == NULL) {
+ DBF_EXCEPTION(1, "cqra nomem\n");
+ kfree(request);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+ /* alloc small kernel buffer */
+ if (datasize > 0) {
+ request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
+ if (request->cpdata == NULL) {
+ DBF_EXCEPTION(1, "cqra nomem\n");
+ kfree(request->cpaddr);
+ kfree(request);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+ 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)
+ tape_put_device(request->device);
+ kfree(request->cpdata);
+ kfree(request->cpaddr);
+ kfree(request);
+}
+
+static int
+__tape_start_io(struct tape_device *device, struct tape_request *request)
+{
+ int rc;
+
+ rc = ccw_device_start(
+ device->cdev,
+ request->cpaddr,
+ (unsigned long) request,
+ 0x00,
+ request->options
+ );
+ if (rc == 0) {
+ request->status = TAPE_REQUEST_IN_IO;
+ } else if (rc == -EBUSY) {
+ /* The common I/O subsystem is currently busy. Retry later. */
+ request->status = TAPE_REQUEST_QUEUED;
+ schedule_delayed_work(&device->tape_dnr, 0);
+ rc = 0;
+ } else {
+ /* Start failed. Remove request and indicate failure. */
+ DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
+ }
+ return rc;
+}
+
+static void
+__tape_start_next_request(struct tape_device *device)
+{
+ struct list_head *l, *n;
+ struct tape_request *request;
+ int rc;
+
+ DBF_LH(6, "__tape_start_next_request(%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);
+
+ /*
+ * Avoid race condition if bottom-half was triggered more than
+ * once.
+ */
+ if (request->status == TAPE_REQUEST_IN_IO)
+ return;
+ /*
+ * Request has already been stopped. We have to wait until
+ * the request is removed from the queue in the interrupt
+ * handling.
+ */
+ if (request->status == TAPE_REQUEST_DONE)
+ return;
+
+ /*
+ * We wanted to cancel the request but the common I/O layer
+ * was busy at that time. This can only happen if this
+ * function is called by delayed_next_request.
+ * Otherwise we start the next request on the queue.
+ */
+ if (request->status == TAPE_REQUEST_CANCEL) {
+ rc = __tape_cancel_io(device, request);
+ } else {
+ rc = __tape_start_io(device, request);
+ }
+ if (rc == 0)
+ return;
+
+ /* Set ending status. */
+ request->rc = rc;
+ request->status = TAPE_REQUEST_DONE;
+
+ /* Remove from request queue. */
+ list_del(&request->list);
+
+ /* Do callback. */
+ if (request->callback != NULL)
+ request->callback(request, request->callback_data);
+ }
+}
+
+static void
+tape_delayed_next_request(struct work_struct *work)
+{
+ struct tape_device *device =
+ container_of(work, struct tape_device, tape_dnr.work);
+
+ DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ __tape_start_next_request(device);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+}
+
+static void tape_long_busy_timeout(unsigned long data)
+{
+ struct tape_request *request;
+ struct tape_device *device;
+
+ device = (struct tape_device *) data;
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ request = list_entry(device->req_queue.next, struct tape_request, list);
+ BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
+ DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
+ __tape_start_next_request(device);
+ device->lb_timeout.data = 0UL;
+ tape_put_device(device);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+}
+
+static void
+__tape_end_request(
+ struct tape_device * device,
+ struct tape_request * request,
+ int rc)
+{
+ DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
+ if (request) {
+ request->rc = rc;
+ request->status = TAPE_REQUEST_DONE;
+
+ /* 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_start_next_request(device);
+}
+
+/*
+ * 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.cmd.dstat, irb->scsw.cmd.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 int
+__tape_start_request(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:
+ case TO_RDC:
+ 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(device);
+
+ if (list_empty(&device->req_queue)) {
+ /* No other requests are on the queue. Start this one. */
+ rc = __tape_start_io(device, request);
+ if (rc)
+ return rc;
+
+ DBF_LH(5, "Request %p added for execution.\n", request);
+ list_add(&request->list, &device->req_queue);
+ } else {
+ DBF_LH(5, "Request %p add to queue.\n", request);
+ request->status = TAPE_REQUEST_QUEUED;
+ list_add_tail(&request->list, &device->req_queue);
+ }
+ 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_start_request(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)
+{
+ int rc;
+
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ /* Setup callback */
+ request->callback = __tape_wake_up;
+ request->callback_data = &device->wait_queue;
+ /* Add request to request queue and try to start it. */
+ rc = __tape_start_request(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(device->wait_queue, (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)
+{
+ int rc;
+
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ /* Setup callback */
+ request->callback = __tape_wake_up_interruptible;
+ request->callback_data = &device->wait_queue;
+ rc = __tape_start_request(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(device->wait_queue,
+ (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_cancel_io(device, request);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ if (rc == 0) {
+ /* Wait for the interrupt that acknowledges the halt. */
+ do {
+ rc = wait_event_interruptible(
+ device->wait_queue,
+ (request->callback == NULL)
+ );
+ } while (rc == -ERESTARTSYS);
+
+ DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
+ rc = -ERESTARTSYS;
+ }
+ return rc;
+}
+
+/*
+ * Stop running ccw.
+ */
+int
+tape_cancel_io(struct tape_device *device, struct tape_request *request)
+{
+ int rc;
+
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ rc = __tape_cancel_io(device, request);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ return rc;
+}
+
+/*
+ * 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 rc;
+
+ device = dev_get_drvdata(&cdev->dev);
+ if (device == NULL) {
+ 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)) {
+ /* FIXME: What to do with the request? */
+ switch (PTR_ERR(irb)) {
+ case -ETIMEDOUT:
+ DBF_LH(1, "(%08x): Request timed out\n",
+ device->cdev_id);
+ case -EIO:
+ __tape_end_request(device, request, -EIO);
+ break;
+ default:
+ DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
+ device->cdev_id, PTR_ERR(irb));
+ }
+ return;
+ }
+
+ /*
+ * If the condition code is not zero and the start function bit is
+ * still set, this is an deferred error and the last start I/O did
+ * not succeed. At this point the condition that caused the deferred
+ * error might still apply. So we just schedule the request to be
+ * started later.
+ */
+ if (irb->scsw.cmd.cc != 0 &&
+ (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
+ (request->status == TAPE_REQUEST_IN_IO)) {
+ DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
+ device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
+ request->status = TAPE_REQUEST_QUEUED;
+ schedule_delayed_work(&device->tape_dnr, HZ);
+ return;
+ }
+
+ /* May be an unsolicited irq */
+ if(request != NULL)
+ request->rescnt = irb->scsw.cmd.count;
+ else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
+ !list_empty(&device->req_queue)) {
+ /* Not Ready to Ready after long busy ? */
+ struct tape_request *req;
+ req = list_entry(device->req_queue.next,
+ struct tape_request, list);
+ if (req->status == TAPE_REQUEST_LONG_BUSY) {
+ DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
+ if (del_timer(&device->lb_timeout)) {
+ device->lb_timeout.data = 0UL;
+ tape_put_device(device);
+ __tape_start_next_request(device);
+ }
+ return;
+ }
+ }
+ if (irb->scsw.cmd.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_end_request(device, request, -EIO);
+ 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.
+ */
+ switch (rc) {
+ case TAPE_IO_SUCCESS:
+ /* Upon normal completion the device _is_ online */
+ device->tape_generic_status |= GMT_ONLINE(~0);
+ __tape_end_request(device, request, rc);
+ break;
+ case TAPE_IO_PENDING:
+ break;
+ case TAPE_IO_LONG_BUSY:
+ device->lb_timeout.data =
+ (unsigned long) tape_get_device(device);
+ device->lb_timeout.expires = jiffies +
+ LONG_BUSY_TIMEOUT * HZ;
+ DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
+ add_timer(&device->lb_timeout);
+ request->status = TAPE_REQUEST_LONG_BUSY;
+ break;
+ case TAPE_IO_RETRY:
+ rc = __tape_start_io(device, request);
+ if (rc)
+ __tape_end_request(device, request, rc);
+ break;
+ case TAPE_IO_STOP:
+ rc = __tape_cancel_io(device, request);
+ if (rc)
+ __tape_end_request(device, request, rc);
+ break;
+ default:
+ if (rc > 0) {
+ DBF_EVENT(6, "xunknownrc\n");
+ __tape_end_request(device, request, -EIO);
+ } else {
+ __tape_end_request(device, request, rc);
+ }
+ break;
+ }
+}
+
+/*
+ * Tape device open function used by tape_char frontend.
+ */
+int
+tape_open(struct tape_device *device)
+{
+ int rc;
+
+ spin_lock_irq(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_irq(get_ccwdev_lock(device->cdev));
+ return rc;
+}
+
+/*
+ * Tape device release function used by tape_char frontend.
+ */
+int
+tape_release(struct tape_device *device)
+{
+ spin_lock_irq(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_irq(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", 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, "tape init\n");
+ tape_proc_init();
+ tapechar_init ();
+ return 0;
+}
+
+/*
+ * Tape exit function.
+ */
+static void
+tape_exit(void)
+{
+ DBF_EVENT(6, "tape exit\n");
+
+ /* Get rid of the frontends */
+ tapechar_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");
+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_generic_pm_suspend);
+EXPORT_SYMBOL(tape_put_device);
+EXPORT_SYMBOL(tape_get_device);
+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_dbf);
+EXPORT_SYMBOL(tape_do_io);
+EXPORT_SYMBOL(tape_do_io_async);
+EXPORT_SYMBOL(tape_do_io_interruptible);
+EXPORT_SYMBOL(tape_cancel_io);
+EXPORT_SYMBOL(tape_mtop);
Code Review / kvmfornfv.git / blobdiff