/* * basic function of the tape device driver * * S390 and zSeries version * Copyright IBM Corp. 2001, 2009 * Author(s): Carsten Otte * Michael Holzheu * Tuan Ngo-Anh * Martin Schwidefsky * Stefan Bader */ #define KMSG_COMPONENT "tape" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include #include // for kernel parameters #include // for requesting modules #include // for locks #include #include #include #include // 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);