X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fs390%2Fcio%2Fdevice_fsm.c;fp=kernel%2Fdrivers%2Fs390%2Fcio%2Fdevice_fsm.c;h=83da53c8e54c5b982d604d1c7f91846404d9072b;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/s390/cio/device_fsm.c b/kernel/drivers/s390/cio/device_fsm.c
new file mode 100644
index 000000000..83da53c8e
--- /dev/null
+++ b/kernel/drivers/s390/cio/device_fsm.c
@@ -0,0 +1,1117 @@
+/*
+ * finite state machine for device handling
+ *
+ *    Copyright IBM Corp. 2002, 2008
+ *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
+ *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+
+#include <asm/ccwdev.h>
+#include <asm/cio.h>
+#include <asm/chpid.h>
+
+#include "cio.h"
+#include "cio_debug.h"
+#include "css.h"
+#include "device.h"
+#include "chsc.h"
+#include "ioasm.h"
+#include "chp.h"
+
+static int timeout_log_enabled;
+
+static int __init ccw_timeout_log_setup(char *unused)
+{
+	timeout_log_enabled = 1;
+	return 1;
+}
+
+__setup("ccw_timeout_log", ccw_timeout_log_setup);
+
+static void ccw_timeout_log(struct ccw_device *cdev)
+{
+	struct schib schib;
+	struct subchannel *sch;
+	struct io_subchannel_private *private;
+	union orb *orb;
+	int cc;
+
+	sch = to_subchannel(cdev->dev.parent);
+	private = to_io_private(sch);
+	orb = &private->orb;
+	cc = stsch_err(sch->schid, &schib);
+
+	printk(KERN_WARNING "cio: ccw device timeout occurred at %llx, "
+	       "device information:\n", get_tod_clock());
+	printk(KERN_WARNING "cio: orb:\n");
+	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
+		       orb, sizeof(*orb), 0);
+	printk(KERN_WARNING "cio: ccw device bus id: %s\n",
+	       dev_name(&cdev->dev));
+	printk(KERN_WARNING "cio: subchannel bus id: %s\n",
+	       dev_name(&sch->dev));
+	printk(KERN_WARNING "cio: subchannel lpm: %02x, opm: %02x, "
+	       "vpm: %02x\n", sch->lpm, sch->opm, sch->vpm);
+
+	if (orb->tm.b) {
+		printk(KERN_WARNING "cio: orb indicates transport mode\n");
+		printk(KERN_WARNING "cio: last tcw:\n");
+		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
+			       (void *)(addr_t)orb->tm.tcw,
+			       sizeof(struct tcw), 0);
+	} else {
+		printk(KERN_WARNING "cio: orb indicates command mode\n");
+		if ((void *)(addr_t)orb->cmd.cpa == &private->sense_ccw ||
+		    (void *)(addr_t)orb->cmd.cpa == cdev->private->iccws)
+			printk(KERN_WARNING "cio: last channel program "
+			       "(intern):\n");
+		else
+			printk(KERN_WARNING "cio: last channel program:\n");
+
+		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
+			       (void *)(addr_t)orb->cmd.cpa,
+			       sizeof(struct ccw1), 0);
+	}
+	printk(KERN_WARNING "cio: ccw device state: %d\n",
+	       cdev->private->state);
+	printk(KERN_WARNING "cio: store subchannel returned: cc=%d\n", cc);
+	printk(KERN_WARNING "cio: schib:\n");
+	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
+		       &schib, sizeof(schib), 0);
+	printk(KERN_WARNING "cio: ccw device flags:\n");
+	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
+		       &cdev->private->flags, sizeof(cdev->private->flags), 0);
+}
+
+/*
+ * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
+ */
+static void
+ccw_device_timeout(unsigned long data)
+{
+	struct ccw_device *cdev;
+
+	cdev = (struct ccw_device *) data;
+	spin_lock_irq(cdev->ccwlock);
+	if (timeout_log_enabled)
+		ccw_timeout_log(cdev);
+	dev_fsm_event(cdev, DEV_EVENT_TIMEOUT);
+	spin_unlock_irq(cdev->ccwlock);
+}
+
+/*
+ * Set timeout
+ */
+void
+ccw_device_set_timeout(struct ccw_device *cdev, int expires)
+{
+	if (expires == 0) {
+		del_timer(&cdev->private->timer);
+		return;
+	}
+	if (timer_pending(&cdev->private->timer)) {
+		if (mod_timer(&cdev->private->timer, jiffies + expires))
+			return;
+	}
+	cdev->private->timer.function = ccw_device_timeout;
+	cdev->private->timer.data = (unsigned long) cdev;
+	cdev->private->timer.expires = jiffies + expires;
+	add_timer(&cdev->private->timer);
+}
+
+/*
+ * Cancel running i/o. This is called repeatedly since halt/clear are
+ * asynchronous operations. We do one try with cio_cancel, two tries
+ * with cio_halt, 255 tries with cio_clear. If everythings fails panic.
+ * Returns 0 if device now idle, -ENODEV for device not operational and
+ * -EBUSY if an interrupt is expected (either from halt/clear or from a
+ * status pending).
+ */
+int
+ccw_device_cancel_halt_clear(struct ccw_device *cdev)
+{
+	struct subchannel *sch;
+	int ret;
+
+	sch = to_subchannel(cdev->dev.parent);
+	if (cio_update_schib(sch))
+		return -ENODEV; 
+	if (!sch->schib.pmcw.ena)
+		/* Not operational -> done. */
+		return 0;
+	/* Stage 1: cancel io. */
+	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
+	    !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
+		if (!scsw_is_tm(&sch->schib.scsw)) {
+			ret = cio_cancel(sch);
+			if (ret != -EINVAL)
+				return ret;
+		}
+		/* cancel io unsuccessful or not applicable (transport mode).
+		 * Continue with asynchronous instructions. */
+		cdev->private->iretry = 3;	/* 3 halt retries. */
+	}
+	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
+		/* Stage 2: halt io. */
+		if (cdev->private->iretry) {
+			cdev->private->iretry--;
+			ret = cio_halt(sch);
+			if (ret != -EBUSY)
+				return (ret == 0) ? -EBUSY : ret;
+		}
+		/* halt io unsuccessful. */
+		cdev->private->iretry = 255;	/* 255 clear retries. */
+	}
+	/* Stage 3: clear io. */
+	if (cdev->private->iretry) {
+		cdev->private->iretry--;
+		ret = cio_clear (sch);
+		return (ret == 0) ? -EBUSY : ret;
+	}
+	/* Function was unsuccessful */
+	CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
+		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno);
+	return -EIO;
+}
+
+void ccw_device_update_sense_data(struct ccw_device *cdev)
+{
+	memset(&cdev->id, 0, sizeof(cdev->id));
+	cdev->id.cu_type   = cdev->private->senseid.cu_type;
+	cdev->id.cu_model  = cdev->private->senseid.cu_model;
+	cdev->id.dev_type  = cdev->private->senseid.dev_type;
+	cdev->id.dev_model = cdev->private->senseid.dev_model;
+}
+
+int ccw_device_test_sense_data(struct ccw_device *cdev)
+{
+	return cdev->id.cu_type == cdev->private->senseid.cu_type &&
+		cdev->id.cu_model == cdev->private->senseid.cu_model &&
+		cdev->id.dev_type == cdev->private->senseid.dev_type &&
+		cdev->id.dev_model == cdev->private->senseid.dev_model;
+}
+
+/*
+ * The machine won't give us any notification by machine check if a chpid has
+ * been varied online on the SE so we have to find out by magic (i. e. driving
+ * the channel subsystem to device selection and updating our path masks).
+ */
+static void
+__recover_lost_chpids(struct subchannel *sch, int old_lpm)
+{
+	int mask, i;
+	struct chp_id chpid;
+
+	chp_id_init(&chpid);
+	for (i = 0; i<8; i++) {
+		mask = 0x80 >> i;
+		if (!(sch->lpm & mask))
+			continue;
+		if (old_lpm & mask)
+			continue;
+		chpid.id = sch->schib.pmcw.chpid[i];
+		if (!chp_is_registered(chpid))
+			css_schedule_eval_all();
+	}
+}
+
+/*
+ * Stop device recognition.
+ */
+static void
+ccw_device_recog_done(struct ccw_device *cdev, int state)
+{
+	struct subchannel *sch;
+	int old_lpm;
+
+	sch = to_subchannel(cdev->dev.parent);
+
+	if (cio_disable_subchannel(sch))
+		state = DEV_STATE_NOT_OPER;
+	/*
+	 * Now that we tried recognition, we have performed device selection
+	 * through ssch() and the path information is up to date.
+	 */
+	old_lpm = sch->lpm;
+
+	/* Check since device may again have become not operational. */
+	if (cio_update_schib(sch))
+		state = DEV_STATE_NOT_OPER;
+	else
+		sch->lpm = sch->schib.pmcw.pam & sch->opm;
+
+	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
+		/* Force reprobe on all chpids. */
+		old_lpm = 0;
+	if (sch->lpm != old_lpm)
+		__recover_lost_chpids(sch, old_lpm);
+	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID &&
+	    (state == DEV_STATE_NOT_OPER || state == DEV_STATE_BOXED)) {
+		cdev->private->flags.recog_done = 1;
+		cdev->private->state = DEV_STATE_DISCONNECTED;
+		wake_up(&cdev->private->wait_q);
+		return;
+	}
+	if (cdev->private->flags.resuming) {
+		cdev->private->state = state;
+		cdev->private->flags.recog_done = 1;
+		wake_up(&cdev->private->wait_q);
+		return;
+	}
+	switch (state) {
+	case DEV_STATE_NOT_OPER:
+		break;
+	case DEV_STATE_OFFLINE:
+		if (!cdev->online) {
+			ccw_device_update_sense_data(cdev);
+			break;
+		}
+		cdev->private->state = DEV_STATE_OFFLINE;
+		cdev->private->flags.recog_done = 1;
+		if (ccw_device_test_sense_data(cdev)) {
+			cdev->private->flags.donotify = 1;
+			ccw_device_online(cdev);
+			wake_up(&cdev->private->wait_q);
+		} else {
+			ccw_device_update_sense_data(cdev);
+			ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
+		}
+		return;
+	case DEV_STATE_BOXED:
+		if (cdev->id.cu_type != 0) { /* device was recognized before */
+			cdev->private->flags.recog_done = 1;
+			cdev->private->state = DEV_STATE_BOXED;
+			wake_up(&cdev->private->wait_q);
+			return;
+		}
+		break;
+	}
+	cdev->private->state = state;
+	io_subchannel_recog_done(cdev);
+	wake_up(&cdev->private->wait_q);
+}
+
+/*
+ * Function called from device_id.c after sense id has completed.
+ */
+void
+ccw_device_sense_id_done(struct ccw_device *cdev, int err)
+{
+	switch (err) {
+	case 0:
+		ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
+		break;
+	case -ETIME:		/* Sense id stopped by timeout. */
+		ccw_device_recog_done(cdev, DEV_STATE_BOXED);
+		break;
+	default:
+		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
+		break;
+	}
+}
+
+/**
+  * ccw_device_notify() - inform the device's driver about an event
+  * @cdev: device for which an event occurred
+  * @event: event that occurred
+  *
+  * Returns:
+  *   -%EINVAL if the device is offline or has no driver.
+  *   -%EOPNOTSUPP if the device's driver has no notifier registered.
+  *   %NOTIFY_OK if the driver wants to keep the device.
+  *   %NOTIFY_BAD if the driver doesn't want to keep the device.
+  */
+int ccw_device_notify(struct ccw_device *cdev, int event)
+{
+	int ret = -EINVAL;
+
+	if (!cdev->drv)
+		goto out;
+	if (!cdev->online)
+		goto out;
+	CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
+		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
+		      event);
+	if (!cdev->drv->notify) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+	if (cdev->drv->notify(cdev, event))
+		ret = NOTIFY_OK;
+	else
+		ret = NOTIFY_BAD;
+out:
+	return ret;
+}
+
+static void ccw_device_oper_notify(struct ccw_device *cdev)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+	if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
+		/* Reenable channel measurements, if needed. */
+		ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
+		/* Save indication for new paths. */
+		cdev->private->path_new_mask = sch->vpm;
+		return;
+	}
+	/* Driver doesn't want device back. */
+	ccw_device_set_notoper(cdev);
+	ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
+}
+
+/*
+ * Finished with online/offline processing.
+ */
+static void
+ccw_device_done(struct ccw_device *cdev, int state)
+{
+	struct subchannel *sch;
+
+	sch = to_subchannel(cdev->dev.parent);
+
+	ccw_device_set_timeout(cdev, 0);
+
+	if (state != DEV_STATE_ONLINE)
+		cio_disable_subchannel(sch);
+
+	/* Reset device status. */
+	memset(&cdev->private->irb, 0, sizeof(struct irb));
+
+	cdev->private->state = state;
+
+	switch (state) {
+	case DEV_STATE_BOXED:
+		CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
+			      cdev->private->dev_id.devno, sch->schid.sch_no);
+		if (cdev->online &&
+		    ccw_device_notify(cdev, CIO_BOXED) != NOTIFY_OK)
+			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+		cdev->private->flags.donotify = 0;
+		break;
+	case DEV_STATE_NOT_OPER:
+		CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
+			      cdev->private->dev_id.devno, sch->schid.sch_no);
+		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
+			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+		else
+			ccw_device_set_disconnected(cdev);
+		cdev->private->flags.donotify = 0;
+		break;
+	case DEV_STATE_DISCONNECTED:
+		CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
+			      "%04x\n", cdev->private->dev_id.devno,
+			      sch->schid.sch_no);
+		if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK) {
+			cdev->private->state = DEV_STATE_NOT_OPER;
+			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+		} else
+			ccw_device_set_disconnected(cdev);
+		cdev->private->flags.donotify = 0;
+		break;
+	default:
+		break;
+	}
+
+	if (cdev->private->flags.donotify) {
+		cdev->private->flags.donotify = 0;
+		ccw_device_oper_notify(cdev);
+	}
+	wake_up(&cdev->private->wait_q);
+}
+
+/*
+ * Start device recognition.
+ */
+void ccw_device_recognition(struct ccw_device *cdev)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+	/*
+	 * We used to start here with a sense pgid to find out whether a device
+	 * is locked by someone else. Unfortunately, the sense pgid command
+	 * code has other meanings on devices predating the path grouping
+	 * algorithm, so we start with sense id and box the device after an
+	 * timeout (or if sense pgid during path verification detects the device
+	 * is locked, as may happen on newer devices).
+	 */
+	cdev->private->flags.recog_done = 0;
+	cdev->private->state = DEV_STATE_SENSE_ID;
+	if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
+		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
+		return;
+	}
+	ccw_device_sense_id_start(cdev);
+}
+
+/*
+ * Handle events for states that use the ccw request infrastructure.
+ */
+static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
+{
+	switch (e) {
+	case DEV_EVENT_NOTOPER:
+		ccw_request_notoper(cdev);
+		break;
+	case DEV_EVENT_INTERRUPT:
+		ccw_request_handler(cdev);
+		break;
+	case DEV_EVENT_TIMEOUT:
+		ccw_request_timeout(cdev);
+		break;
+	default:
+		break;
+	}
+}
+
+static void ccw_device_report_path_events(struct ccw_device *cdev)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	int path_event[8];
+	int chp, mask;
+
+	for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
+		path_event[chp] = PE_NONE;
+		if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
+			path_event[chp] |= PE_PATH_GONE;
+		if (mask & cdev->private->path_new_mask & sch->vpm)
+			path_event[chp] |= PE_PATH_AVAILABLE;
+		if (mask & cdev->private->pgid_reset_mask & sch->vpm)
+			path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
+	}
+	if (cdev->online && cdev->drv->path_event)
+		cdev->drv->path_event(cdev, path_event);
+}
+
+static void ccw_device_reset_path_events(struct ccw_device *cdev)
+{
+	cdev->private->path_gone_mask = 0;
+	cdev->private->path_new_mask = 0;
+	cdev->private->pgid_reset_mask = 0;
+}
+
+static void create_fake_irb(struct irb *irb, int type)
+{
+	memset(irb, 0, sizeof(*irb));
+	if (type == FAKE_CMD_IRB) {
+		struct cmd_scsw *scsw = &irb->scsw.cmd;
+		scsw->cc = 1;
+		scsw->fctl = SCSW_FCTL_START_FUNC;
+		scsw->actl = SCSW_ACTL_START_PEND;
+		scsw->stctl = SCSW_STCTL_STATUS_PEND;
+	} else if (type == FAKE_TM_IRB) {
+		struct tm_scsw *scsw = &irb->scsw.tm;
+		scsw->x = 1;
+		scsw->cc = 1;
+		scsw->fctl = SCSW_FCTL_START_FUNC;
+		scsw->actl = SCSW_ACTL_START_PEND;
+		scsw->stctl = SCSW_STCTL_STATUS_PEND;
+	}
+}
+
+void ccw_device_verify_done(struct ccw_device *cdev, int err)
+{
+	struct subchannel *sch;
+
+	sch = to_subchannel(cdev->dev.parent);
+	/* Update schib - pom may have changed. */
+	if (cio_update_schib(sch)) {
+		err = -ENODEV;
+		goto callback;
+	}
+	/* Update lpm with verified path mask. */
+	sch->lpm = sch->vpm;
+	/* Repeat path verification? */
+	if (cdev->private->flags.doverify) {
+		ccw_device_verify_start(cdev);
+		return;
+	}
+callback:
+	switch (err) {
+	case 0:
+		ccw_device_done(cdev, DEV_STATE_ONLINE);
+		/* Deliver fake irb to device driver, if needed. */
+		if (cdev->private->flags.fake_irb) {
+			create_fake_irb(&cdev->private->irb,
+					cdev->private->flags.fake_irb);
+			cdev->private->flags.fake_irb = 0;
+			if (cdev->handler)
+				cdev->handler(cdev, cdev->private->intparm,
+					      &cdev->private->irb);
+			memset(&cdev->private->irb, 0, sizeof(struct irb));
+		}
+		ccw_device_report_path_events(cdev);
+		break;
+	case -ETIME:
+	case -EUSERS:
+		/* Reset oper notify indication after verify error. */
+		cdev->private->flags.donotify = 0;
+		ccw_device_done(cdev, DEV_STATE_BOXED);
+		break;
+	case -EACCES:
+		/* Reset oper notify indication after verify error. */
+		cdev->private->flags.donotify = 0;
+		ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
+		break;
+	default:
+		/* Reset oper notify indication after verify error. */
+		cdev->private->flags.donotify = 0;
+		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
+		break;
+	}
+	ccw_device_reset_path_events(cdev);
+}
+
+/*
+ * Get device online.
+ */
+int
+ccw_device_online(struct ccw_device *cdev)
+{
+	struct subchannel *sch;
+	int ret;
+
+	if ((cdev->private->state != DEV_STATE_OFFLINE) &&
+	    (cdev->private->state != DEV_STATE_BOXED))
+		return -EINVAL;
+	sch = to_subchannel(cdev->dev.parent);
+	ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
+	if (ret != 0) {
+		/* Couldn't enable the subchannel for i/o. Sick device. */
+		if (ret == -ENODEV)
+			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
+		return ret;
+	}
+	/* Start initial path verification. */
+	cdev->private->state = DEV_STATE_VERIFY;
+	ccw_device_verify_start(cdev);
+	return 0;
+}
+
+void
+ccw_device_disband_done(struct ccw_device *cdev, int err)
+{
+	switch (err) {
+	case 0:
+		ccw_device_done(cdev, DEV_STATE_OFFLINE);
+		break;
+	case -ETIME:
+		ccw_device_done(cdev, DEV_STATE_BOXED);
+		break;
+	default:
+		cdev->private->flags.donotify = 0;
+		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
+		break;
+	}
+}
+
+/*
+ * Shutdown device.
+ */
+int
+ccw_device_offline(struct ccw_device *cdev)
+{
+	struct subchannel *sch;
+
+	/* Allow ccw_device_offline while disconnected. */
+	if (cdev->private->state == DEV_STATE_DISCONNECTED ||
+	    cdev->private->state == DEV_STATE_NOT_OPER) {
+		cdev->private->flags.donotify = 0;
+		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
+		return 0;
+	}
+	if (cdev->private->state == DEV_STATE_BOXED) {
+		ccw_device_done(cdev, DEV_STATE_BOXED);
+		return 0;
+	}
+	if (ccw_device_is_orphan(cdev)) {
+		ccw_device_done(cdev, DEV_STATE_OFFLINE);
+		return 0;
+	}
+	sch = to_subchannel(cdev->dev.parent);
+	if (cio_update_schib(sch))
+		return -ENODEV;
+	if (scsw_actl(&sch->schib.scsw) != 0)
+		return -EBUSY;
+	if (cdev->private->state != DEV_STATE_ONLINE)
+		return -EINVAL;
+	/* Are we doing path grouping? */
+	if (!cdev->private->flags.pgroup) {
+		/* No, set state offline immediately. */
+		ccw_device_done(cdev, DEV_STATE_OFFLINE);
+		return 0;
+	}
+	/* Start Set Path Group commands. */
+	cdev->private->state = DEV_STATE_DISBAND_PGID;
+	ccw_device_disband_start(cdev);
+	return 0;
+}
+
+/*
+ * Handle not operational event in non-special state.
+ */
+static void ccw_device_generic_notoper(struct ccw_device *cdev,
+				       enum dev_event dev_event)
+{
+	if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
+		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+	else
+		ccw_device_set_disconnected(cdev);
+}
+
+/*
+ * Handle path verification event in offline state.
+ */
+static void ccw_device_offline_verify(struct ccw_device *cdev,
+				      enum dev_event dev_event)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+	css_schedule_eval(sch->schid);
+}
+
+/*
+ * Handle path verification event.
+ */
+static void
+ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	struct subchannel *sch;
+
+	if (cdev->private->state == DEV_STATE_W4SENSE) {
+		cdev->private->flags.doverify = 1;
+		return;
+	}
+	sch = to_subchannel(cdev->dev.parent);
+	/*
+	 * Since we might not just be coming from an interrupt from the
+	 * subchannel we have to update the schib.
+	 */
+	if (cio_update_schib(sch)) {
+		ccw_device_verify_done(cdev, -ENODEV);
+		return;
+	}
+
+	if (scsw_actl(&sch->schib.scsw) != 0 ||
+	    (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
+	    (scsw_stctl(&cdev->private->irb.scsw) & SCSW_STCTL_STATUS_PEND)) {
+		/*
+		 * No final status yet or final status not yet delivered
+		 * to the device driver. Can't do path verification now,
+		 * delay until final status was delivered.
+		 */
+		cdev->private->flags.doverify = 1;
+		return;
+	}
+	/* Device is idle, we can do the path verification. */
+	cdev->private->state = DEV_STATE_VERIFY;
+	ccw_device_verify_start(cdev);
+}
+
+/*
+ * Handle path verification event in boxed state.
+ */
+static void ccw_device_boxed_verify(struct ccw_device *cdev,
+				    enum dev_event dev_event)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+	if (cdev->online) {
+		if (cio_enable_subchannel(sch, (u32) (addr_t) sch))
+			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
+		else
+			ccw_device_online_verify(cdev, dev_event);
+	} else
+		css_schedule_eval(sch->schid);
+}
+
+/*
+ * Got an interrupt for a normal io (state online).
+ */
+static void
+ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	struct irb *irb;
+	int is_cmd;
+
+	irb = this_cpu_ptr(&cio_irb);
+	is_cmd = !scsw_is_tm(&irb->scsw);
+	/* Check for unsolicited interrupt. */
+	if (!scsw_is_solicited(&irb->scsw)) {
+		if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
+		    !irb->esw.esw0.erw.cons) {
+			/* Unit check but no sense data. Need basic sense. */
+			if (ccw_device_do_sense(cdev, irb) != 0)
+				goto call_handler_unsol;
+			memcpy(&cdev->private->irb, irb, sizeof(struct irb));
+			cdev->private->state = DEV_STATE_W4SENSE;
+			cdev->private->intparm = 0;
+			return;
+		}
+call_handler_unsol:
+		if (cdev->handler)
+			cdev->handler (cdev, 0, irb);
+		if (cdev->private->flags.doverify)
+			ccw_device_online_verify(cdev, 0);
+		return;
+	}
+	/* Accumulate status and find out if a basic sense is needed. */
+	ccw_device_accumulate_irb(cdev, irb);
+	if (is_cmd && cdev->private->flags.dosense) {
+		if (ccw_device_do_sense(cdev, irb) == 0) {
+			cdev->private->state = DEV_STATE_W4SENSE;
+		}
+		return;
+	}
+	/* Call the handler. */
+	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
+		/* Start delayed path verification. */
+		ccw_device_online_verify(cdev, 0);
+}
+
+/*
+ * Got an timeout in online state.
+ */
+static void
+ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	int ret;
+
+	ccw_device_set_timeout(cdev, 0);
+	cdev->private->iretry = 255;
+	ret = ccw_device_cancel_halt_clear(cdev);
+	if (ret == -EBUSY) {
+		ccw_device_set_timeout(cdev, 3*HZ);
+		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
+		return;
+	}
+	if (ret)
+		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
+	else if (cdev->handler)
+		cdev->handler(cdev, cdev->private->intparm,
+			      ERR_PTR(-ETIMEDOUT));
+}
+
+/*
+ * Got an interrupt for a basic sense.
+ */
+static void
+ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	struct irb *irb;
+
+	irb = this_cpu_ptr(&cio_irb);
+	/* Check for unsolicited interrupt. */
+	if (scsw_stctl(&irb->scsw) ==
+	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
+		if (scsw_cc(&irb->scsw) == 1)
+			/* Basic sense hasn't started. Try again. */
+			ccw_device_do_sense(cdev, irb);
+		else {
+			CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
+				      "interrupt during w4sense...\n",
+				      cdev->private->dev_id.ssid,
+				      cdev->private->dev_id.devno);
+			if (cdev->handler)
+				cdev->handler (cdev, 0, irb);
+		}
+		return;
+	}
+	/*
+	 * Check if a halt or clear has been issued in the meanwhile. If yes,
+	 * only deliver the halt/clear interrupt to the device driver as if it
+	 * had killed the original request.
+	 */
+	if (scsw_fctl(&irb->scsw) &
+	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
+		cdev->private->flags.dosense = 0;
+		memset(&cdev->private->irb, 0, sizeof(struct irb));
+		ccw_device_accumulate_irb(cdev, irb);
+		goto call_handler;
+	}
+	/* Add basic sense info to irb. */
+	ccw_device_accumulate_basic_sense(cdev, irb);
+	if (cdev->private->flags.dosense) {
+		/* Another basic sense is needed. */
+		ccw_device_do_sense(cdev, irb);
+		return;
+	}
+call_handler:
+	cdev->private->state = DEV_STATE_ONLINE;
+	/* In case sensing interfered with setting the device online */
+	wake_up(&cdev->private->wait_q);
+	/* Call the handler. */
+	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
+		/* Start delayed path verification. */
+		ccw_device_online_verify(cdev, 0);
+}
+
+static void
+ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	ccw_device_set_timeout(cdev, 0);
+	/* Start delayed path verification. */
+	ccw_device_online_verify(cdev, 0);
+	/* OK, i/o is dead now. Call interrupt handler. */
+	if (cdev->handler)
+		cdev->handler(cdev, cdev->private->intparm,
+			      ERR_PTR(-EIO));
+}
+
+static void
+ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	int ret;
+
+	ret = ccw_device_cancel_halt_clear(cdev);
+	if (ret == -EBUSY) {
+		ccw_device_set_timeout(cdev, 3*HZ);
+		return;
+	}
+	/* Start delayed path verification. */
+	ccw_device_online_verify(cdev, 0);
+	if (cdev->handler)
+		cdev->handler(cdev, cdev->private->intparm,
+			      ERR_PTR(-EIO));
+}
+
+void ccw_device_kill_io(struct ccw_device *cdev)
+{
+	int ret;
+
+	cdev->private->iretry = 255;
+	ret = ccw_device_cancel_halt_clear(cdev);
+	if (ret == -EBUSY) {
+		ccw_device_set_timeout(cdev, 3*HZ);
+		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
+		return;
+	}
+	/* Start delayed path verification. */
+	ccw_device_online_verify(cdev, 0);
+	if (cdev->handler)
+		cdev->handler(cdev, cdev->private->intparm,
+			      ERR_PTR(-EIO));
+}
+
+static void
+ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	/* Start verification after current task finished. */
+	cdev->private->flags.doverify = 1;
+}
+
+static void
+ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	struct subchannel *sch;
+
+	sch = to_subchannel(cdev->dev.parent);
+	if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
+		/* Couldn't enable the subchannel for i/o. Sick device. */
+		return;
+	cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
+	ccw_device_sense_id_start(cdev);
+}
+
+void ccw_device_trigger_reprobe(struct ccw_device *cdev)
+{
+	struct subchannel *sch;
+
+	if (cdev->private->state != DEV_STATE_DISCONNECTED)
+		return;
+
+	sch = to_subchannel(cdev->dev.parent);
+	/* Update some values. */
+	if (cio_update_schib(sch))
+		return;
+	/*
+	 * The pim, pam, pom values may not be accurate, but they are the best
+	 * we have before performing device selection :/
+	 */
+	sch->lpm = sch->schib.pmcw.pam & sch->opm;
+	/*
+	 * Use the initial configuration since we can't be shure that the old
+	 * paths are valid.
+	 */
+	io_subchannel_init_config(sch);
+	if (cio_commit_config(sch))
+		return;
+
+	/* We should also udate ssd info, but this has to wait. */
+	/* Check if this is another device which appeared on the same sch. */
+	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
+		css_schedule_eval(sch->schid);
+	else
+		ccw_device_start_id(cdev, 0);
+}
+
+static void ccw_device_disabled_irq(struct ccw_device *cdev,
+				    enum dev_event dev_event)
+{
+	struct subchannel *sch;
+
+	sch = to_subchannel(cdev->dev.parent);
+	/*
+	 * An interrupt in a disabled state means a previous disable was not
+	 * successful - should not happen, but we try to disable again.
+	 */
+	cio_disable_subchannel(sch);
+}
+
+static void
+ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	retry_set_schib(cdev);
+	cdev->private->state = DEV_STATE_ONLINE;
+	dev_fsm_event(cdev, dev_event);
+}
+
+static void ccw_device_update_cmfblock(struct ccw_device *cdev,
+				       enum dev_event dev_event)
+{
+	cmf_retry_copy_block(cdev);
+	cdev->private->state = DEV_STATE_ONLINE;
+	dev_fsm_event(cdev, dev_event);
+}
+
+static void
+ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	ccw_device_set_timeout(cdev, 0);
+	cdev->private->state = DEV_STATE_NOT_OPER;
+	wake_up(&cdev->private->wait_q);
+}
+
+static void
+ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
+{
+	int ret;
+
+	ret = ccw_device_cancel_halt_clear(cdev);
+	if (ret == -EBUSY) {
+		ccw_device_set_timeout(cdev, HZ/10);
+	} else {
+		cdev->private->state = DEV_STATE_NOT_OPER;
+		wake_up(&cdev->private->wait_q);
+	}
+}
+
+/*
+ * No operation action. This is used e.g. to ignore a timeout event in
+ * state offline.
+ */
+static void
+ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
+{
+}
+
+/*
+ * device statemachine
+ */
+fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
+	[DEV_STATE_NOT_OPER] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop,
+	},
+	[DEV_STATE_SENSE_PGID] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop,
+	},
+	[DEV_STATE_SENSE_ID] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop,
+	},
+	[DEV_STATE_OFFLINE] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
+		[DEV_EVENT_VERIFY]	= ccw_device_offline_verify,
+	},
+	[DEV_STATE_VERIFY] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
+		[DEV_EVENT_VERIFY]	= ccw_device_delay_verify,
+	},
+	[DEV_STATE_ONLINE] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_irq,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_online_timeout,
+		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
+	},
+	[DEV_STATE_W4SENSE] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_w4sense,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
+		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
+	},
+	[DEV_STATE_DISBAND_PGID] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop,
+	},
+	[DEV_STATE_BOXED] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_nop,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
+		[DEV_EVENT_VERIFY]	= ccw_device_boxed_verify,
+	},
+	/* states to wait for i/o completion before doing something */
+	[DEV_STATE_TIMEOUT_KILL] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_killing_timeout,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop, //FIXME
+	},
+	[DEV_STATE_QUIESCE] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_quiesce_done,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_quiesce_done,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_quiesce_timeout,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop,
+	},
+	/* special states for devices gone not operational */
+	[DEV_STATE_DISCONNECTED] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_start_id,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
+		[DEV_EVENT_VERIFY]	= ccw_device_start_id,
+	},
+	[DEV_STATE_DISCONNECTED_SENSE_ID] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop,
+	},
+	[DEV_STATE_CMFCHANGE] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_change_cmfstate,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_change_cmfstate,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_change_cmfstate,
+		[DEV_EVENT_VERIFY]	= ccw_device_change_cmfstate,
+	},
+	[DEV_STATE_CMFUPDATE] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_update_cmfblock,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_update_cmfblock,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_update_cmfblock,
+		[DEV_EVENT_VERIFY]	= ccw_device_update_cmfblock,
+	},
+	[DEV_STATE_STEAL_LOCK] = {
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
+		[DEV_EVENT_VERIFY]	= ccw_device_nop,
+	},
+};
+
+EXPORT_SYMBOL_GPL(ccw_device_set_timeout);