device_fsm.c

linux-2.6.15.6

}

static void
ccw_device_clear_verify(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct irb *irb;

	irb = (struct irb *) __LC_IRB;
	/* Accumulate status. We don't do basic sense. */
	ccw_device_accumulate_irb(cdev, irb);
	/* Try to start delayed device verification. */
	ccw_device_online_verify(cdev, 0);
	/* Note: Don't call handler for cio initiated clear! */
}

static void
ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);
	ccw_device_set_timeout(cdev, 0);
	/* OK, i/o is dead now. Call interrupt handler. */
	cdev->private->state = DEV_STATE_ONLINE;
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-ETIMEDOUT));
	if (!sch->lpm) {
		PREPARE_WORK(&cdev->private->kick_work,
			     ccw_device_nopath_notify, (void *)cdev);
		queue_work(ccw_device_notify_work, &cdev->private->kick_work);
	} else if (cdev->private->flags.doverify)
		/* Start delayed path verification. */
		ccw_device_online_verify(cdev, 0);
}

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;
	}
	if (ret == -ENODEV) {
		struct subchannel *sch;

		sch = to_subchannel(cdev->dev.parent);
		if (!sch->lpm) {
			PREPARE_WORK(&cdev->private->kick_work,
				     ccw_device_nopath_notify, (void *)cdev);
			queue_work(ccw_device_notify_work,
				   &cdev->private->kick_work);
		} else
			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
		return;
	}
	//FIXME: Can we get here?
	cdev->private->state = DEV_STATE_ONLINE;
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-ETIMEDOUT));
}

static void
ccw_device_wait4io_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct irb *irb;
	struct subchannel *sch;

	irb = (struct irb *) __LC_IRB;
	/*
	 * Accumulate status and find out if a basic sense is needed.
	 * This is fine since we have already adapted the lpm.
	 */
	ccw_device_accumulate_irb(cdev, irb);
	if (cdev->private->flags.dosense) {
		if (ccw_device_do_sense(cdev, irb) == 0) {
			cdev->private->state = DEV_STATE_W4SENSE;
		}
		return;
	}

	/* Iff device is idle, reset timeout. */
	sch = to_subchannel(cdev->dev.parent);
	if (!stsch(sch->irq, &sch->schib))
		if (sch->schib.scsw.actl == 0)
			ccw_device_set_timeout(cdev, 0);
	/* Call the handler. */
	ccw_device_call_handler(cdev);
	if (!sch->lpm) {
		PREPARE_WORK(&cdev->private->kick_work,
			     ccw_device_nopath_notify, (void *)cdev);
		queue_work(ccw_device_notify_work, &cdev->private->kick_work);
	} else if (cdev->private->flags.doverify)
		ccw_device_online_verify(cdev, 0);
}

static void
ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event)
{
	int ret;
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);
	ccw_device_set_timeout(cdev, 0);
	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 == -ENODEV) {
		if (!sch->lpm) {
			PREPARE_WORK(&cdev->private->kick_work,
				     ccw_device_nopath_notify, (void *)cdev);
			queue_work(ccw_device_notify_work,
				   &cdev->private->kick_work);
		} else
			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
		return;
	}
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-ETIMEDOUT));
	if (!sch->lpm) {
		PREPARE_WORK(&cdev->private->kick_work,
			     ccw_device_nopath_notify, (void *)cdev);
		queue_work(ccw_device_notify_work, &cdev->private->kick_work);
	} else if (cdev->private->flags.doverify)
		/* Start delayed path verification. */
		ccw_device_online_verify(cdev, 0);
}

static void
ccw_device_wait4io_verify(struct ccw_device *cdev, enum dev_event dev_event)
{
	/* When the I/O has terminated, we have to start verification. */
	if (cdev->private->options.pgroup)
		cdev->private->flags.doverify = 1;
}

static void
ccw_device_stlck_done(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct irb *irb;

	switch (dev_event) {
	case DEV_EVENT_INTERRUPT:
		irb = (struct irb *) __LC_IRB;
		/* Check for unsolicited interrupt. */
		if ((irb->scsw.stctl ==
		     (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) &&
		    (!irb->scsw.cc))
			/* FIXME: we should restart stlck here, but this
			 * is extremely unlikely ... */
			goto out_wakeup;

		ccw_device_accumulate_irb(cdev, irb);
		/* We don't care about basic sense etc. */
		break;
	default: /* timeout */
		break;
	}
out_wakeup:
	wake_up(&cdev->private->wait_q);
}

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, sch->schib.pmcw.isc) != 0)
		/* Couldn't enable the subchannel for i/o. Sick device. */
		return;

	/* After 60s the device recognition is considered to have failed. */
	ccw_device_set_timeout(cdev, 60*HZ);

	cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
	ccw_device_sense_id_start(cdev);
}

void
device_trigger_reprobe(struct subchannel *sch)
{
	struct ccw_device *cdev;

	if (!sch->dev.driver_data)
		return;
	cdev = sch->dev.driver_data;
	if (cdev->private->state != DEV_STATE_DISCONNECTED)
		return;

	/* Update some values. */
	if (stsch(sch->irq, &sch->schib))
		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.pim &
		sch->schib.pmcw.pam &
		sch->schib.pmcw.pom &
		sch->opm;
	/* Re-set some bits in the pmcw that were lost. */
	sch->schib.pmcw.isc = 3;
	sch->schib.pmcw.csense = 1;
	sch->schib.pmcw.ena = 0;
	if ((sch->lpm & (sch->lpm - 1)) != 0)
		sch->schib.pmcw.mp = 1;
	sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
	/* We should also udate ssd info, but this has to wait. */
	ccw_device_start_id(cdev, 0);
}

static void
ccw_device_offline_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);
	/*
	 * An interrupt in state offline means a previous disable was not
	 * successful. Try 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_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
{
	ccw_device_set_timeout(cdev, 0);
	if (dev_event == DEV_EVENT_NOTOPER)
		cdev->private->state = DEV_STATE_NOT_OPER;
	else
		cdev->private->state = DEV_STATE_OFFLINE;
	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);
	switch (ret) {
	case 0:
		cdev->private->state = DEV_STATE_OFFLINE;
		wake_up(&cdev->private->wait_q);
		break;
	case -ENODEV:
		cdev->private->state = DEV_STATE_NOT_OPER;
		wake_up(&cdev->private->wait_q);
		break;
	default:
		ccw_device_set_timeout(cdev, HZ/10);
	}
}

/*
 * 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)
{
}

/*
 * Bug operation action. 
 */
static void
ccw_device_bug(struct ccw_device *cdev, enum dev_event dev_event)
{
	printk(KERN_EMERG "dev_jumptable[%i][%i] == NULL\n",
	       cdev->private->state, dev_event);
	BUG();
}

/*
 * 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_bug,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_SENSE_PGID] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_online_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_sense_pgid_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_onoff_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_SENSE_ID] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_recog_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_sense_id_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_recog_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_OFFLINE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_offline_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_offline_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_VERIFY] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_online_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_verify_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_onoff_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_ONLINE] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_online_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_online_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_online_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_disband_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_onoff_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_BOXED] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_offline_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_stlck_done,
		[DEV_EVENT_TIMEOUT]	= ccw_device_stlck_done,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	/* states to wait for i/o completion before doing something */
	[DEV_STATE_CLEAR_VERIFY] = {
		[DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
		[DEV_EVENT_INTERRUPT]   = ccw_device_clear_verify,
		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_TIMEOUT_KILL] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_online_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_killing_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_nop, //FIXME
	},
	[DEV_STATE_WAIT4IO] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_online_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_wait4io_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_wait4io_timeout,
		[DEV_EVENT_VERIFY]	= ccw_device_wait4io_verify,
	},
	[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_bug,
		[DEV_EVENT_VERIFY]	= ccw_device_nop,
	},
	[DEV_STATE_DISCONNECTED_SENSE_ID] = {
		[DEV_EVENT_NOTOPER]	= ccw_device_recog_notoper,
		[DEV_EVENT_INTERRUPT]	= ccw_device_sense_id_irq,
		[DEV_EVENT_TIMEOUT]	= ccw_device_recog_timeout,
		[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,
	},
};

/*
 * io_subchannel_irq is called for "real" interrupts or for status
 * pending conditions on msch.
 */
void
io_subchannel_irq (struct device *pdev)
{
	struct ccw_device *cdev;

	cdev = to_subchannel(pdev)->dev.driver_data;

	CIO_TRACE_EVENT (3, "IRQ");
	CIO_TRACE_EVENT (3, pdev->bus_id);
	if (cdev)
		dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
}

EXPORT_SYMBOL_GPL(ccw_device_set_timeout);