Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1135 insertions, 0 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
new file mode 100644
index 000000000000..df0325505e4e
--- /dev/null
+++ b/drivers/s390/cio/device.c
@@ -0,0 +1,1135 @@
+/*
+ *  drivers/s390/cio/device.c
+ *  bus driver for ccw devices
+ *   $Revision: 1.131 $
+ *
+ *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
+ *                       IBM Corporation
+ *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
+ *               Cornelia Huck (cohuck@de.ibm.com)
+ *               Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/device.h>
+#include <linux/workqueue.h>
+
+#include <asm/ccwdev.h>
+#include <asm/cio.h>
+
+#include "cio.h"
+#include "css.h"
+#include "device.h"
+#include "ioasm.h"
+
+/******************* bus type handling ***********************/
+
+/* The Linux driver model distinguishes between a bus type and
+ * the bus itself. Of course we only have one channel
+ * subsystem driver and one channel system per machine, but
+ * we still use the abstraction. T.R. says it's a good idea. */
+static int
+ccw_bus_match (struct device * dev, struct device_driver * drv)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct ccw_driver *cdrv = to_ccwdrv(drv);
+        const struct ccw_device_id *ids = cdrv->ids, *found;
+
+        if (!ids)
+                return 0;
+
+        found = ccw_device_id_match(ids, &cdev->id);
+        if (!found)
+                return 0;
+
+        cdev->id.driver_info = found->driver_info;
+
+        return 1;
+}
+
+/*
+ * Hotplugging interface for ccw devices.
+ * Heavily modeled on pci and usb hotplug.
+ */
+static int
+ccw_hotplug (struct device *dev, char **envp, int num_envp,
+             char *buffer, int buffer_size)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        int i = 0;
+        int length = 0;
+
+        if (!cdev)
+                return -ENODEV;
+
+        /* what we want to pass to /sbin/hotplug */
+
+        envp[i++] = buffer;
+        length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
+                           cdev->id.cu_type);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        buffer += length;
+
+        envp[i++] = buffer;
+        length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
+                           cdev->id.cu_model);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        buffer += length;
+
+        /* The next two can be zero, that's ok for us */
+        envp[i++] = buffer;
+        length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
+                           cdev->id.dev_type);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        buffer += length;
+
+        envp[i++] = buffer;
+        length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
+                           cdev->id.dev_model);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+
+        envp[i] = 0;
+
+        return 0;
+}
+
+struct bus_type ccw_bus_type = {
+        .name  = "ccw",
+        .match = &ccw_bus_match,
+        .hotplug = &ccw_hotplug,
+};
+
+static int io_subchannel_probe (struct device *);
+static int io_subchannel_remove (struct device *);
+void io_subchannel_irq (struct device *);
+static int io_subchannel_notify(struct device *, int);
+static void io_subchannel_verify(struct device *);
+static void io_subchannel_ioterm(struct device *);
+static void io_subchannel_shutdown(struct device *);
+
+struct css_driver io_subchannel_driver = {
+        .subchannel_type = SUBCHANNEL_TYPE_IO,
+        .drv = {
+                .name = "io_subchannel",
+                .bus  = &css_bus_type,
+                .probe = &io_subchannel_probe,
+                .remove = &io_subchannel_remove,
+                .shutdown = &io_subchannel_shutdown,
+        },
+        .irq = io_subchannel_irq,
+        .notify = io_subchannel_notify,
+        .verify = io_subchannel_verify,
+        .termination = io_subchannel_ioterm,
+};
+
+struct workqueue_struct *ccw_device_work;
+struct workqueue_struct *ccw_device_notify_work;
+static wait_queue_head_t ccw_device_init_wq;
+static atomic_t ccw_device_init_count;
+
+static int __init
+init_ccw_bus_type (void)
+{
+        int ret;
+
+        init_waitqueue_head(&ccw_device_init_wq);
+        atomic_set(&ccw_device_init_count, 0);
+
+        ccw_device_work = create_singlethread_workqueue("cio");
+        if (!ccw_device_work)
+                return -ENOMEM; /* FIXME: better errno ? */
+        ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
+        if (!ccw_device_notify_work) {
+                ret = -ENOMEM; /* FIXME: better errno ? */
+                goto out_err;
+        }
+        slow_path_wq = create_singlethread_workqueue("kslowcrw");
+        if (!slow_path_wq) {
+                ret = -ENOMEM; /* FIXME: better errno ? */
+                goto out_err;
+        }
+        if ((ret = bus_register (&ccw_bus_type)))
+                goto out_err;
+
+        if ((ret = driver_register(&io_subchannel_driver.drv)))
+                goto out_err;
+
+        wait_event(ccw_device_init_wq,
+                   atomic_read(&ccw_device_init_count) == 0);
+        flush_workqueue(ccw_device_work);
+        return 0;
+out_err:
+        if (ccw_device_work)
+                destroy_workqueue(ccw_device_work);
+        if (ccw_device_notify_work)
+                destroy_workqueue(ccw_device_notify_work);
+        if (slow_path_wq)
+                destroy_workqueue(slow_path_wq);
+        return ret;
+}
+
+static void __exit
+cleanup_ccw_bus_type (void)
+{
+        driver_unregister(&io_subchannel_driver.drv);
+        bus_unregister(&ccw_bus_type);
+        destroy_workqueue(ccw_device_notify_work);
+        destroy_workqueue(ccw_device_work);
+}
+
+subsys_initcall(init_ccw_bus_type);
+module_exit(cleanup_ccw_bus_type);
+
+/************************ device handling **************************/
+
+/*
+ * A ccw_device has some interfaces in sysfs in addition to the
+ * standard ones.
+ * The following entries are designed to export the information which
+ * resided in 2.4 in /proc/subchannels. Subchannel and device number
+ * are obvious, so they don't have an entry :)
+ * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
+ */
+static ssize_t
+chpids_show (struct device * dev, char * buf)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        struct ssd_info *ssd = &sch->ssd_info;
+        ssize_t ret = 0;
+        int chp;
+
+        for (chp = 0; chp < 8; chp++)
+                ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
+
+        ret += sprintf (buf+ret, "\n");
+        return min((ssize_t)PAGE_SIZE, ret);
+}
+
+static ssize_t
+pimpampom_show (struct device * dev, char * buf)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        struct pmcw *pmcw = &sch->schib.pmcw;
+
+        return sprintf (buf, "%02x %02x %02x\n",
+                        pmcw->pim, pmcw->pam, pmcw->pom);
+}
+
+static ssize_t
+devtype_show (struct device *dev, char *buf)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct ccw_device_id *id = &(cdev->id);
+
+        if (id->dev_type != 0)
+                return sprintf(buf, "%04x/%02x\n",
+                                id->dev_type, id->dev_model);
+        else
+                return sprintf(buf, "n/a\n");
+}
+
+static ssize_t
+cutype_show (struct device *dev, char *buf)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct ccw_device_id *id = &(cdev->id);
+
+        return sprintf(buf, "%04x/%02x\n",
+                       id->cu_type, id->cu_model);
+}
+
+static ssize_t
+online_show (struct device *dev, char *buf)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+
+        return sprintf(buf, cdev->online ? "1\n" : "0\n");
+}
+
+static void
+ccw_device_remove_disconnected(struct ccw_device *cdev)
+{
+        struct subchannel *sch;
+        /*
+         * Forced offline in disconnected state means
+         * 'throw away device'.
+         */
+        sch = to_subchannel(cdev->dev.parent);
+        device_unregister(&sch->dev);
+        /* Reset intparm to zeroes. */
+        sch->schib.pmcw.intparm = 0;
+        cio_modify(sch);
+        put_device(&sch->dev);
+}
+
+int
+ccw_device_set_offline(struct ccw_device *cdev)
+{
+        int ret;
+
+        if (!cdev)
+                return -ENODEV;
+        if (!cdev->online || !cdev->drv)
+                return -EINVAL;
+
+        if (cdev->drv->set_offline) {
+                ret = cdev->drv->set_offline(cdev);
+                if (ret != 0)
+                        return ret;
+        }
+        cdev->online = 0;
+        spin_lock_irq(cdev->ccwlock);
+        ret = ccw_device_offline(cdev);
+        if (ret == -ENODEV) {
+                if (cdev->private->state != DEV_STATE_NOT_OPER) {
+                        cdev->private->state = DEV_STATE_OFFLINE;
+                        dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
+                }
+                spin_unlock_irq(cdev->ccwlock);
+                return ret;
+        }
+        spin_unlock_irq(cdev->ccwlock);
+        if (ret == 0)
+                wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
+        else {
+                pr_debug("ccw_device_offline returned %d, device %s\n",
+                         ret, cdev->dev.bus_id);
+                cdev->online = 1;
+        }
+        return ret;
+}
+
+int
+ccw_device_set_online(struct ccw_device *cdev)
+{
+        int ret;
+
+        if (!cdev)
+                return -ENODEV;
+        if (cdev->online || !cdev->drv)
+                return -EINVAL;
+
+        spin_lock_irq(cdev->ccwlock);
+        ret = ccw_device_online(cdev);
+        spin_unlock_irq(cdev->ccwlock);
+        if (ret == 0)
+                wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
+        else {
+                pr_debug("ccw_device_online returned %d, device %s\n",
+                         ret, cdev->dev.bus_id);
+                return ret;
+        }
+        if (cdev->private->state != DEV_STATE_ONLINE)
+                return -ENODEV;
+        if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
+                cdev->online = 1;
+                return 0;
+        }
+        spin_lock_irq(cdev->ccwlock);
+        ret = ccw_device_offline(cdev);
+        spin_unlock_irq(cdev->ccwlock);
+        if (ret == 0)
+                wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
+        else 
+                pr_debug("ccw_device_offline returned %d, device %s\n",
+                         ret, cdev->dev.bus_id);
+        return (ret = 0) ? -ENODEV : ret;
+}
+
+static ssize_t
+online_store (struct device *dev, const char *buf, size_t count)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        int i, force, ret;
+        char *tmp;
+
+        if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
+                return -EAGAIN;
+
+        if (cdev->drv && !try_module_get(cdev->drv->owner)) {
+                atomic_set(&cdev->private->onoff, 0);
+                return -EINVAL;
+        }
+        if (!strncmp(buf, "force\n", count)) {
+                force = 1;
+                i = 1;
+        } else {
+                force = 0;
+                i = simple_strtoul(buf, &tmp, 16);
+        }
+        if (i == 1) {
+                /* Do device recognition, if needed. */
+                if (cdev->id.cu_type == 0) {
+                        ret = ccw_device_recognition(cdev);
+                        if (ret) {
+                                printk(KERN_WARNING"Couldn't start recognition "
+                                       "for device %s (ret=%d)\n",
+                                       cdev->dev.bus_id, ret);
+                                goto out;
+                        }
+                        wait_event(cdev->private->wait_q,
+                                   cdev->private->flags.recog_done);
+                }
+                if (cdev->drv && cdev->drv->set_online)
+                        ccw_device_set_online(cdev);
+        } else if (i == 0) {
+                if (cdev->private->state == DEV_STATE_DISCONNECTED)
+                        ccw_device_remove_disconnected(cdev);
+                else if (cdev->drv && cdev->drv->set_offline)
+                        ccw_device_set_offline(cdev);
+        }
+        if (force && cdev->private->state == DEV_STATE_BOXED) {
+                ret = ccw_device_stlck(cdev);
+                if (ret) {
+                        printk(KERN_WARNING"ccw_device_stlck for device %s "
+                               "returned %d!\n", cdev->dev.bus_id, ret);
+                        goto out;
+                }
+                /* Do device recognition, if needed. */
+                if (cdev->id.cu_type == 0) {
+                        cdev->private->state = DEV_STATE_NOT_OPER;
+                        ret = ccw_device_recognition(cdev);
+                        if (ret) {
+                                printk(KERN_WARNING"Couldn't start recognition "
+                                       "for device %s (ret=%d)\n",
+                                       cdev->dev.bus_id, ret);
+                                goto out;
+                        }
+                        wait_event(cdev->private->wait_q,
+                                   cdev->private->flags.recog_done);
+                }
+                if (cdev->drv && cdev->drv->set_online)
+                        ccw_device_set_online(cdev);
+        }
+        out:
+        if (cdev->drv)
+                module_put(cdev->drv->owner);
+        atomic_set(&cdev->private->onoff, 0);
+        return count;
+}
+
+static ssize_t
+available_show (struct device *dev, char *buf)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct subchannel *sch;
+
+        switch (cdev->private->state) {
+        case DEV_STATE_BOXED:
+                return sprintf(buf, "boxed\n");
+        case DEV_STATE_DISCONNECTED:
+        case DEV_STATE_DISCONNECTED_SENSE_ID:
+        case DEV_STATE_NOT_OPER:
+                sch = to_subchannel(dev->parent);
+                if (!sch->lpm)
+                        return sprintf(buf, "no path\n");
+                else
+                        return sprintf(buf, "no device\n");
+        default:
+                /* All other states considered fine. */
+                return sprintf(buf, "good\n");
+        }
+}
+
+static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
+static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
+static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
+static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
+static DEVICE_ATTR(online, 0644, online_show, online_store);
+extern struct device_attribute dev_attr_cmb_enable;
+static DEVICE_ATTR(availability, 0444, available_show, NULL);
+
+static struct attribute * subch_attrs[] = {
+        &dev_attr_chpids.attr,
+        &dev_attr_pimpampom.attr,
+        NULL,
+};
+
+static struct attribute_group subch_attr_group = {
+        .attrs = subch_attrs,
+};
+
+static inline int
+subchannel_add_files (struct device *dev)
+{
+        return sysfs_create_group(&dev->kobj, &subch_attr_group);
+}
+
+static struct attribute * ccwdev_attrs[] = {
+        &dev_attr_devtype.attr,
+        &dev_attr_cutype.attr,
+        &dev_attr_online.attr,
+        &dev_attr_cmb_enable.attr,
+        &dev_attr_availability.attr,
+        NULL,
+};
+
+static struct attribute_group ccwdev_attr_group = {
+        .attrs = ccwdev_attrs,
+};
+
+static inline int
+device_add_files (struct device *dev)
+{
+        return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
+}
+
+static inline void
+device_remove_files(struct device *dev)
+{
+        sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
+}
+
+/* this is a simple abstraction for device_register that sets the
+ * correct bus type and adds the bus specific files */
+int
+ccw_device_register(struct ccw_device *cdev)
+{
+        struct device *dev = &cdev->dev;
+        int ret;
+
+        dev->bus = &ccw_bus_type;
+
+        if ((ret = device_add(dev)))
+                return ret;
+
+        set_bit(1, &cdev->private->registered);
+        if ((ret = device_add_files(dev))) {
+                if (test_and_clear_bit(1, &cdev->private->registered))
+                        device_del(dev);
+        }
+        return ret;
+}
+
+static struct ccw_device *
+get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
+{
+        struct ccw_device *cdev;
+        struct list_head *entry;
+        struct device *dev;
+
+        if (!get_bus(&ccw_bus_type))
+                return NULL;
+        down_read(&ccw_bus_type.subsys.rwsem);
+        cdev = NULL;
+        list_for_each(entry, &ccw_bus_type.devices.list) {
+                dev = get_device(container_of(entry,
+                                              struct device, bus_list));
+                if (!dev)
+                        continue;
+                cdev = to_ccwdev(dev);
+                if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
+                    (cdev->private->devno == devno) &&
+                    (cdev != sibling)) {
+                        cdev->private->state = DEV_STATE_NOT_OPER;
+                        break;
+                }
+                put_device(dev);
+                cdev = NULL;
+        }
+        up_read(&ccw_bus_type.subsys.rwsem);
+        put_bus(&ccw_bus_type);
+
+        return cdev;
+}
+
+static void
+ccw_device_add_changed(void *data)
+{
+
+        struct ccw_device *cdev;
+
+        cdev = (struct ccw_device *)data;
+        if (device_add(&cdev->dev)) {
+                put_device(&cdev->dev);
+                return;
+        }
+        set_bit(1, &cdev->private->registered);
+        if (device_add_files(&cdev->dev)) {
+                if (test_and_clear_bit(1, &cdev->private->registered))
+                        device_unregister(&cdev->dev);
+        }
+}
+
+extern int css_get_ssd_info(struct subchannel *sch);
+
+void
+ccw_device_do_unreg_rereg(void *data)
+{
+        struct ccw_device *cdev;
+        struct subchannel *sch;
+        int need_rename;
+
+        cdev = (struct ccw_device *)data;
+        sch = to_subchannel(cdev->dev.parent);
+        if (cdev->private->devno != sch->schib.pmcw.dev) {
+                /*
+                 * The device number has changed. This is usually only when
+                 * a device has been detached under VM and then re-appeared
+                 * on another subchannel because of a different attachment
+                 * order than before. Ideally, we should should just switch
+                 * subchannels, but unfortunately, this is not possible with
+                 * the current implementation.
+                 * Instead, we search for the old subchannel for this device
+                 * number and deregister so there are no collisions with the
+                 * newly registered ccw_device.
+                 * FIXME: Find another solution so the block layer doesn't
+                 *        get possibly sick...
+                 */
+                struct ccw_device *other_cdev;
+
+                need_rename = 1;
+                other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
+                                                      cdev);
+                if (other_cdev) {
+                        struct subchannel *other_sch;
+
+                        other_sch = to_subchannel(other_cdev->dev.parent);
+                        if (get_device(&other_sch->dev)) {
+                                stsch(other_sch->irq, &other_sch->schib);
+                                if (other_sch->schib.pmcw.dnv) {
+                                        other_sch->schib.pmcw.intparm = 0;
+                                        cio_modify(other_sch);
+                                }
+                                device_unregister(&other_sch->dev);
+                        }
+                }
+                /* Update ssd info here. */
+                css_get_ssd_info(sch);
+                cdev->private->devno = sch->schib.pmcw.dev;
+        } else
+                need_rename = 0;
+        device_remove_files(&cdev->dev);
+        if (test_and_clear_bit(1, &cdev->private->registered))
+                device_del(&cdev->dev);
+        if (need_rename)
+                snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
+                          sch->schib.pmcw.dev);
+        PREPARE_WORK(&cdev->private->kick_work,
+                     ccw_device_add_changed, (void *)cdev);
+        queue_work(ccw_device_work, &cdev->private->kick_work);
+}
+
+static void
+ccw_device_release(struct device *dev)
+{
+        struct ccw_device *cdev;
+
+        cdev = to_ccwdev(dev);
+        kfree(cdev->private);
+        kfree(cdev);
+}
+
+/*
+ * Register recognized device.
+ */
+static void
+io_subchannel_register(void *data)
+{
+        struct ccw_device *cdev;
+        struct subchannel *sch;
+        int ret;
+        unsigned long flags;
+
+        cdev = (struct ccw_device *) data;
+        sch = to_subchannel(cdev->dev.parent);
+
+        if (!list_empty(&sch->dev.children)) {
+                bus_rescan_devices(&ccw_bus_type);
+                goto out;
+        }
+        /* make it known to the system */
+        ret = ccw_device_register(cdev);
+        if (ret) {
+                printk (KERN_WARNING "%s: could not register %s\n",
+                        __func__, cdev->dev.bus_id);
+                put_device(&cdev->dev);
+                spin_lock_irqsave(&sch->lock, flags);
+                sch->dev.driver_data = NULL;
+                spin_unlock_irqrestore(&sch->lock, flags);
+                kfree (cdev->private);
+                kfree (cdev);
+                put_device(&sch->dev);
+                if (atomic_dec_and_test(&ccw_device_init_count))
+                        wake_up(&ccw_device_init_wq);
+                return;
+        }
+
+        ret = subchannel_add_files(cdev->dev.parent);
+        if (ret)
+                printk(KERN_WARNING "%s: could not add attributes to %s\n",
+                       __func__, sch->dev.bus_id);
+        put_device(&cdev->dev);
+out:
+        cdev->private->flags.recog_done = 1;
+        put_device(&sch->dev);
+        wake_up(&cdev->private->wait_q);
+        if (atomic_dec_and_test(&ccw_device_init_count))
+                wake_up(&ccw_device_init_wq);
+}
+
+void
+ccw_device_call_sch_unregister(void *data)
+{
+        struct ccw_device *cdev = data;
+        struct subchannel *sch;
+
+        sch = to_subchannel(cdev->dev.parent);
+        device_unregister(&sch->dev);
+        /* Reset intparm to zeroes. */
+        sch->schib.pmcw.intparm = 0;
+        cio_modify(sch);
+        put_device(&cdev->dev);
+        put_device(&sch->dev);
+}
+
+/*
+ * subchannel recognition done. Called from the state machine.
+ */
+void
+io_subchannel_recog_done(struct ccw_device *cdev)
+{
+        struct subchannel *sch;
+
+        if (css_init_done == 0) {
+                cdev->private->flags.recog_done = 1;
+                return;
+        }
+        switch (cdev->private->state) {
+        case DEV_STATE_NOT_OPER:
+                cdev->private->flags.recog_done = 1;
+                /* Remove device found not operational. */
+                if (!get_device(&cdev->dev))
+                        break;
+                sch = to_subchannel(cdev->dev.parent);
+                PREPARE_WORK(&cdev->private->kick_work,
+                             ccw_device_call_sch_unregister, (void *) cdev);
+                queue_work(slow_path_wq, &cdev->private->kick_work);
+                if (atomic_dec_and_test(&ccw_device_init_count))
+                        wake_up(&ccw_device_init_wq);
+                break;
+        case DEV_STATE_BOXED:
+                /* Device did not respond in time. */
+        case DEV_STATE_OFFLINE:
+                /* 
+                 * We can't register the device in interrupt context so
+                 * we schedule a work item.
+                 */
+                if (!get_device(&cdev->dev))
+                        break;
+                PREPARE_WORK(&cdev->private->kick_work,
+                             io_subchannel_register, (void *) cdev);
+                queue_work(slow_path_wq, &cdev->private->kick_work);
+                break;
+        }
+}
+
+static int
+io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
+{
+        int rc;
+        struct ccw_device_private *priv;
+
+        sch->dev.driver_data = cdev;
+        sch->driver = &io_subchannel_driver;
+        cdev->ccwlock = &sch->lock;
+        /* Init private data. */
+        priv = cdev->private;
+        priv->devno = sch->schib.pmcw.dev;
+        priv->irq = sch->irq;
+        priv->state = DEV_STATE_NOT_OPER;
+        INIT_LIST_HEAD(&priv->cmb_list);
+        init_waitqueue_head(&priv->wait_q);
+        init_timer(&priv->timer);
+
+        /* Set an initial name for the device. */
+        snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
+                  sch->schib.pmcw.dev);
+
+        /* Increase counter of devices currently in recognition. */
+        atomic_inc(&ccw_device_init_count);
+
+        /* Start async. device sensing. */
+        spin_lock_irq(&sch->lock);
+        rc = ccw_device_recognition(cdev);
+        spin_unlock_irq(&sch->lock);
+        if (rc) {
+                if (atomic_dec_and_test(&ccw_device_init_count))
+                        wake_up(&ccw_device_init_wq);
+        }
+        return rc;
+}
+
+static int
+io_subchannel_probe (struct device *pdev)
+{
+        struct subchannel *sch;
+        struct ccw_device *cdev;
+        int rc;
+        unsigned long flags;
+
+        sch = to_subchannel(pdev);
+        if (sch->dev.driver_data) {
+                /*
+                 * This subchannel already has an associated ccw_device.
+                 * Register it and exit. This happens for all early
+                 * device, e.g. the console.
+                 */
+                cdev = sch->dev.driver_data;
+                device_initialize(&cdev->dev);
+                ccw_device_register(cdev);
+                subchannel_add_files(&sch->dev);
+                /*
+                 * Check if the device is already online. If it is
+                 * the reference count needs to be corrected
+                 * (see ccw_device_online and css_init_done for the
+                 * ugly details).
+                 */
+                if (cdev->private->state != DEV_STATE_NOT_OPER &&
+                    cdev->private->state != DEV_STATE_OFFLINE &&
+                    cdev->private->state != DEV_STATE_BOXED)
+                        get_device(&cdev->dev);
+                return 0;
+        }
+        cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
+        if (!cdev)
+                return -ENOMEM;
+        memset(cdev, 0, sizeof(struct ccw_device));
+        cdev->private = kmalloc(sizeof(struct ccw_device_private), 
+                                GFP_KERNEL | GFP_DMA);
+        if (!cdev->private) {
+                kfree(cdev);
+                return -ENOMEM;
+        }
+        memset(cdev->private, 0, sizeof(struct ccw_device_private));
+        atomic_set(&cdev->private->onoff, 0);
+        cdev->dev = (struct device) {
+                .parent = pdev,
+                .release = ccw_device_release,
+        };
+        INIT_LIST_HEAD(&cdev->private->kick_work.entry);
+        /* Do first half of device_register. */
+        device_initialize(&cdev->dev);
+
+        if (!get_device(&sch->dev)) {
+                if (cdev->dev.release)
+                        cdev->dev.release(&cdev->dev);
+                return -ENODEV;
+        }
+
+        rc = io_subchannel_recog(cdev, to_subchannel(pdev));
+        if (rc) {
+                spin_lock_irqsave(&sch->lock, flags);
+                sch->dev.driver_data = NULL;
+                spin_unlock_irqrestore(&sch->lock, flags);
+                if (cdev->dev.release)
+                        cdev->dev.release(&cdev->dev);
+        }
+
+        return rc;
+}
+
+static void
+ccw_device_unregister(void *data)
+{
+        struct ccw_device *cdev;
+
+        cdev = (struct ccw_device *)data;
+        if (test_and_clear_bit(1, &cdev->private->registered))
+                device_unregister(&cdev->dev);
+        put_device(&cdev->dev);
+}
+
+static int
+io_subchannel_remove (struct device *dev)
+{
+        struct ccw_device *cdev;
+        unsigned long flags;
+
+        if (!dev->driver_data)
+                return 0;
+        cdev = dev->driver_data;
+        /* Set ccw device to not operational and drop reference. */
+        spin_lock_irqsave(cdev->ccwlock, flags);
+        dev->driver_data = NULL;
+        cdev->private->state = DEV_STATE_NOT_OPER;
+        spin_unlock_irqrestore(cdev->ccwlock, flags);
+        /*
+         * Put unregistration on workqueue to avoid livelocks on the css bus
+         * semaphore.
+         */
+        if (get_device(&cdev->dev)) {
+                PREPARE_WORK(&cdev->private->kick_work,
+                             ccw_device_unregister, (void *) cdev);
+                queue_work(ccw_device_work, &cdev->private->kick_work);
+        }
+        return 0;
+}
+
+static int
+io_subchannel_notify(struct device *dev, int event)
+{
+        struct ccw_device *cdev;
+
+        cdev = dev->driver_data;
+        if (!cdev)
+                return 0;
+        if (!cdev->drv)
+                return 0;
+        if (!cdev->online)
+                return 0;
+        return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
+}
+
+static void
+io_subchannel_verify(struct device *dev)
+{
+        struct ccw_device *cdev;
+
+        cdev = dev->driver_data;
+        if (cdev)
+                dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+}
+
+static void
+io_subchannel_ioterm(struct device *dev)
+{
+        struct ccw_device *cdev;
+
+        cdev = dev->driver_data;
+        if (!cdev)
+                return;
+        cdev->private->state = DEV_STATE_CLEAR_VERIFY;
+        if (cdev->handler)
+                cdev->handler(cdev, cdev->private->intparm,
+                              ERR_PTR(-EIO));
+}
+
+static void
+io_subchannel_shutdown(struct device *dev)
+{
+        struct subchannel *sch;
+        struct ccw_device *cdev;
+        int ret;
+
+        sch = to_subchannel(dev);
+        cdev = dev->driver_data;
+
+        if (cio_is_console(sch->irq))
+                return;
+        if (!sch->schib.pmcw.ena)
+                /* Nothing to do. */
+                return;
+        ret = cio_disable_subchannel(sch);
+        if (ret != -EBUSY)
+                /* Subchannel is disabled, we're done. */
+                return;
+        cdev->private->state = DEV_STATE_QUIESCE;
+        if (cdev->handler)
+                cdev->handler(cdev, cdev->private->intparm,
+                              ERR_PTR(-EIO));
+        ret = ccw_device_cancel_halt_clear(cdev);
+        if (ret == -EBUSY) {
+                ccw_device_set_timeout(cdev, HZ/10);
+                wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
+        }
+        cio_disable_subchannel(sch);
+}
+
+#ifdef CONFIG_CCW_CONSOLE
+static struct ccw_device console_cdev;
+static struct ccw_device_private console_private;
+static int console_cdev_in_use;
+
+static int
+ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
+{
+        int rc;
+
+        /* Initialize the ccw_device structure. */
+        cdev->dev = (struct device) {
+                .parent = &sch->dev,
+        };
+        /* Initialize the subchannel structure */
+        sch->dev.parent = &css_bus_device;
+        sch->dev.bus = &css_bus_type;
+
+        rc = io_subchannel_recog(cdev, sch);
+        if (rc)
+                return rc;
+
+        /* Now wait for the async. recognition to come to an end. */
+        spin_lock_irq(cdev->ccwlock);
+        while (!dev_fsm_final_state(cdev))
+                wait_cons_dev();
+        rc = -EIO;
+        if (cdev->private->state != DEV_STATE_OFFLINE)
+                goto out_unlock;
+        ccw_device_online(cdev);
+        while (!dev_fsm_final_state(cdev))
+                wait_cons_dev();
+        if (cdev->private->state != DEV_STATE_ONLINE)
+                goto out_unlock;
+        rc = 0;
+out_unlock:
+        spin_unlock_irq(cdev->ccwlock);
+        return 0;
+}
+
+struct ccw_device *
+ccw_device_probe_console(void)
+{
+        struct subchannel *sch;
+        int ret;
+
+        if (xchg(&console_cdev_in_use, 1) != 0)
+                return NULL;
+        sch = cio_probe_console();
+        if (IS_ERR(sch)) {
+                console_cdev_in_use = 0;
+                return (void *) sch;
+        }
+        memset(&console_cdev, 0, sizeof(struct ccw_device));
+        memset(&console_private, 0, sizeof(struct ccw_device_private));
+        console_cdev.private = &console_private;
+        ret = ccw_device_console_enable(&console_cdev, sch);
+        if (ret) {
+                cio_release_console();
+                console_cdev_in_use = 0;
+                return ERR_PTR(ret);
+        }
+        console_cdev.online = 1;
+        return &console_cdev;
+}
+#endif
+
+/*
+ * get ccw_device matching the busid, but only if owned by cdrv
+ */
+struct ccw_device *
+get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
+{
+        struct device *d, *dev;
+        struct device_driver *drv;
+
+        drv = get_driver(&cdrv->driver);
+        if (!drv)
+                return 0;
+
+        down_read(&drv->bus->subsys.rwsem);
+
+        dev = NULL;
+        list_for_each_entry(d, &drv->devices, driver_list) {
+                dev = get_device(d);
+
+                if (dev && !strncmp(bus_id, dev->bus_id, BUS_ID_SIZE))
+                        break;
+                else if (dev) {
+                        put_device(dev);
+                        dev = NULL;
+                }
+        }
+        up_read(&drv->bus->subsys.rwsem);
+        put_driver(drv);
+
+        return dev ? to_ccwdev(dev) : 0;
+}
+
+/************************** device driver handling ************************/
+
+/* This is the implementation of the ccw_driver class. The probe, remove
+ * and release methods are initially very similar to the device_driver
+ * implementations, with the difference that they have ccw_device
+ * arguments.
+ *
+ * A ccw driver also contains the information that is needed for
+ * device matching.
+ */
+static int
+ccw_device_probe (struct device *dev)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
+        int ret;
+
+        cdev->drv = cdrv; /* to let the driver call _set_online */
+
+        ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
+
+        if (ret) {
+                cdev->drv = 0;
+                return ret;
+        }
+
+        return 0;
+}
+
+static int
+ccw_device_remove (struct device *dev)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct ccw_driver *cdrv = cdev->drv;
+        int ret;
+
+        pr_debug("removing device %s\n", cdev->dev.bus_id);
+        if (cdrv->remove)
+                cdrv->remove(cdev);
+        if (cdev->online) {
+                cdev->online = 0;
+                spin_lock_irq(cdev->ccwlock);
+                ret = ccw_device_offline(cdev);
+                spin_unlock_irq(cdev->ccwlock);
+                if (ret == 0)
+                        wait_event(cdev->private->wait_q,
+                                   dev_fsm_final_state(cdev));
+                else
+                        //FIXME: we can't fail!
+                        pr_debug("ccw_device_offline returned %d, device %s\n",
+                                 ret, cdev->dev.bus_id);
+        }
+        ccw_device_set_timeout(cdev, 0);
+        cdev->drv = 0;
+        return 0;
+}
+
+int
+ccw_driver_register (struct ccw_driver *cdriver)
+{
+        struct device_driver *drv = &cdriver->driver;
+
+        drv->bus = &ccw_bus_type;
+        drv->name = cdriver->name;
+        drv->probe = ccw_device_probe;
+        drv->remove = ccw_device_remove;
+
+        return driver_register(drv);
+}
+
+void
+ccw_driver_unregister (struct ccw_driver *cdriver)
+{
+        driver_unregister(&cdriver->driver);
+}
+
+MODULE_LICENSE("GPL");
+EXPORT_SYMBOL(ccw_device_set_online);
+EXPORT_SYMBOL(ccw_device_set_offline);
+EXPORT_SYMBOL(ccw_driver_register);
+EXPORT_SYMBOL(ccw_driver_unregister);
+EXPORT_SYMBOL(get_ccwdev_by_busid);
+EXPORT_SYMBOL(ccw_bus_type);
+EXPORT_SYMBOL(ccw_device_work);
+EXPORT_SYMBOL(ccw_device_notify_work);