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 00000000000..df0325505e4
--- /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);