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Commit 28bdc6f6 authored by Peter Oberparleiter's avatar Peter Oberparleiter Committed by Martin Schwidefsky
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[S390] cio: always query all paths on path verification. 



Reappearing channel paths are sometimes not utilized by CCW devices
because path verification incorrectly relies on path-operational-mask
information which is not updated until a channel path has been used
again.
Modify path verification procedure to always query all available paths
to a device.

Signed-off-by: default avatarPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e0e32c8e

drivers/s390/cio/chsc.c

+1 −1
Original line number Diff line number Diff line
@@ -256,7 +256,7 @@ s390_subchannel_remove_chpid(struct device *dev, void *data) 
	/* trigger path verification. */

	if (sch->driver && sch->driver->verify)

		sch->driver->verify(&sch->dev);

	else if (sch->vpm == mask)

	else if (sch->lpm == mask)

		goto out_unreg;

out_unlock:

	spin_unlock_irq(&sch->lock);

drivers/s390/cio/cio.c

+1 −4
Original line number Diff line number Diff line
@@ -569,10 +569,7 @@ cio_validate_subchannel (struct subchannel *sch, struct subchannel_id schid) 
	sch->opm = 0xff;

	if (!cio_is_console(sch->schid))

		chsc_validate_chpids(sch);

	sch->lpm = sch->schib.pmcw.pim &

		sch->schib.pmcw.pam &

		sch->schib.pmcw.pom &

		sch->opm;

	sch->lpm = sch->schib.pmcw.pam & sch->opm;



	CIO_DEBUG(KERN_INFO, 0,

		  "Detected device %04x on subchannel 0.%x.%04X"

drivers/s390/cio/device_fsm.c

+23 −16
Original line number Diff line number Diff line
@@ -232,10 +232,7 @@ ccw_device_recog_done(struct ccw_device *cdev, int state) 
	 */

	old_lpm = sch->lpm;

	stsch(sch->schid, &sch->schib);

	sch->lpm = sch->schib.pmcw.pim &

		sch->schib.pmcw.pam &

		sch->schib.pmcw.pom &

		sch->opm;

	sch->lpm = sch->schib.pmcw.pam & sch->opm;

	/* Check since device may again have become not operational. */

	if (!sch->schib.pmcw.dnv)

		state = DEV_STATE_NOT_OPER;
@@ -455,8 +452,8 @@ ccw_device_sense_pgid_done(struct ccw_device *cdev, int err) 
		return;

	}

	/* Start Path Group verification. */

	sch->vpm = 0;	/* Start with no path groups set. */

	cdev->private->state = DEV_STATE_VERIFY;

	cdev->private->flags.doverify = 0;

	ccw_device_verify_start(cdev);

}
@@ -556,7 +553,19 @@ ccw_device_nopath_notify(void *data) 
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. */

	stsch(sch->schid, &sch->schib);

	/* Update lpm with verified path mask. */

	sch->lpm = sch->vpm;

	/* Repeat path verification? */

	if (cdev->private->flags.doverify) {

		cdev->private->flags.doverify = 0;

		ccw_device_verify_start(cdev);

		return;

	}

	switch (err) {

	case -EOPNOTSUPP: /* path grouping not supported, just set online. */

		cdev->private->options.pgroup = 0;
@@ -614,6 +623,7 @@ ccw_device_online(struct ccw_device *cdev) 
	if (!cdev->private->options.pgroup) {

		/* Start initial path verification. */

		cdev->private->state = DEV_STATE_VERIFY;

		cdev->private->flags.doverify = 0;

		ccw_device_verify_start(cdev);

		return 0;

	}
@@ -660,7 +670,6 @@ ccw_device_offline(struct ccw_device *cdev) 
	/* Are we doing path grouping? */

	if (!cdev->private->options.pgroup) {

		/* No, set state offline immediately. */

		sch->vpm = 0;

		ccw_device_done(cdev, DEV_STATE_OFFLINE);

		return 0;

	}
@@ -781,6 +790,7 @@ ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event) 
	}

	/* Device is idle, we can do the path verification. */

	cdev->private->state = DEV_STATE_VERIFY;

	cdev->private->flags.doverify = 0;

	ccw_device_verify_start(cdev);

}
@@ -1043,9 +1053,9 @@ ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event) 
}



static void

ccw_device_wait4io_verify(struct ccw_device *cdev, enum dev_event dev_event)

ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)

{

	/* When the I/O has terminated, we have to start verification. */

	/* Start verification after current task finished. */

	cdev->private->flags.doverify = 1;

}
@@ -1111,10 +1121,7 @@ device_trigger_reprobe(struct subchannel *sch) 
	 * 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;

	sch->lpm = sch->schib.pmcw.pam & sch->opm;

	/* Re-set some bits in the pmcw that were lost. */

	sch->schib.pmcw.isc = 3;

	sch->schib.pmcw.csense = 1;
@@ -1238,7 +1245,7 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = { 
		[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_EVENT_VERIFY]	= ccw_device_delay_verify,

	},

	[DEV_STATE_ONLINE] = {

		[DEV_EVENT_NOTOPER]	= ccw_device_online_notoper,
@@ -1281,7 +1288,7 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = { 
		[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_EVENT_VERIFY]	= ccw_device_delay_verify,

	},

	[DEV_STATE_QUIESCE] = {

		[DEV_EVENT_NOTOPER]	= ccw_device_quiesce_done,
@@ -1294,7 +1301,7 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = { 
		[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_EVENT_VERIFY]	= ccw_device_start_id,

	},

	[DEV_STATE_DISCONNECTED_SENSE_ID] = {

		[DEV_EVENT_NOTOPER]	= ccw_device_recog_notoper,

drivers/s390/cio/device_ops.c

+1 −1
Original line number Diff line number Diff line
@@ -256,7 +256,7 @@ ccw_device_get_path_mask(struct ccw_device *cdev) 
	if (!sch)

		return 0;

	else

		return sch->vpm;

		return sch->lpm;

}



static void

drivers/s390/cio/device_pgid.c

+42 −39
Original line number Diff line number Diff line
@@ -245,18 +245,17 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func) 
	memset(&cdev->private->irb, 0, sizeof(struct irb));



	/* Try multiple times. */

	ret = -ENODEV;

	ret = -EACCES;

	if (cdev->private->iretry > 0) {

		cdev->private->iretry--;

		ret = cio_start (sch, cdev->private->iccws,

				 cdev->private->imask);

		/* ret is 0, -EBUSY, -EACCES or -ENODEV */

		if ((ret != -EACCES) && (ret != -ENODEV))

		/* We expect an interrupt in case of success or busy

		 * indication. */

		if ((ret == 0) || (ret == -EBUSY))

			return ret;

	}

	/* PGID command failed on this path. Switch it off. */

	sch->lpm &= ~cdev->private->imask;

	sch->vpm &= ~cdev->private->imask;

	/* PGID command failed on this path. */

	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "

		      "0.%x.%04x, lpm %02X, became 'not operational'\n",

		      cdev->private->devno, sch->schid.ssid,
@@ -286,18 +285,17 @@ static int __ccw_device_do_nop(struct ccw_device *cdev) 
	memset(&cdev->private->irb, 0, sizeof(struct irb));



	/* Try multiple times. */

	ret = -ENODEV;

	ret = -EACCES;

	if (cdev->private->iretry > 0) {

		cdev->private->iretry--;

		ret = cio_start (sch, cdev->private->iccws,

				 cdev->private->imask);

		/* ret is 0, -EBUSY, -EACCES or -ENODEV */

		if ((ret != -EACCES) && (ret != -ENODEV))

		/* We expect an interrupt in case of success or busy

		 * indication. */

		if ((ret == 0) || (ret == -EBUSY))

			return ret;

	}

	/* nop command failed on this path. Switch it off. */

	sch->lpm &= ~cdev->private->imask;

	sch->vpm &= ~cdev->private->imask;

	/* nop command failed on this path. */

	CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "

		      "0.%x.%04x, lpm %02X, became 'not operational'\n",

		      cdev->private->devno, sch->schid.ssid,
@@ -372,27 +370,32 @@ static void 
__ccw_device_verify_start(struct ccw_device *cdev)

{

	struct subchannel *sch;

	__u8 imask, func;

	__u8 func;

	int ret;



	sch = to_subchannel(cdev->dev.parent);

	while (sch->vpm != sch->lpm) {

		/* Find first unequal bit in vpm vs. lpm */

		for (imask = 0x80; imask != 0; imask >>= 1)

			if ((sch->vpm & imask) != (sch->lpm & imask))

				break;

		cdev->private->imask = imask;

	/* Repeat for all paths. */

	for (; cdev->private->imask; cdev->private->imask >>= 1,

				     cdev->private->iretry = 5) {

		if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)

			/* Path not available, try next. */

			continue;

		if (cdev->private->options.pgroup) {

			func = (sch->vpm & imask) ?

				SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;

			if (sch->opm & cdev->private->imask)

				func = SPID_FUNC_ESTABLISH;

			else

				func = SPID_FUNC_RESIGN;

			ret = __ccw_device_do_pgid(cdev, func);

		} else

			ret = __ccw_device_do_nop(cdev);

		/* We expect an interrupt in case of success or busy

		 * indication. */

		if (ret == 0 || ret == -EBUSY)

			return;

		cdev->private->iretry = 5;

		/* Permanent path failure, try next. */

	}

	ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);

	/* Done with all paths. */

	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);

}

		

/*
@@ -421,14 +424,14 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event) 
	else

		ret = __ccw_device_check_nop(cdev);

	memset(&cdev->private->irb, 0, sizeof(struct irb));



	switch (ret) {

	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */

	case 0:

		/* Establish or Resign Path Group done. Update vpm. */

		if ((sch->lpm & cdev->private->imask) != 0)

			sch->vpm |= cdev->private->imask;

		else

			sch->vpm &= ~cdev->private->imask;

		/* Path verification ccw finished successfully, update lpm. */

		sch->vpm |= sch->opm & cdev->private->imask;

		/* Go on with next path. */

		cdev->private->imask >>= 1;

		cdev->private->iretry = 5;

		__ccw_device_verify_start(cdev);

		break;
@@ -441,6 +444,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event) 
			cdev->private->options.pgroup = 0;

		else

			cdev->private->flags.pgid_single = 1;

		/* Retry */

		sch->vpm = 0;

		cdev->private->imask = 0x80;

		cdev->private->iretry = 5;

		/* fall through. */

	case -EAGAIN:		/* Try again. */

		__ccw_device_verify_start(cdev);
@@ -449,8 +456,7 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event) 
		ccw_device_verify_done(cdev, -ETIME);

		break;

	case -EACCES:		/* channel is not operational. */

		sch->lpm &= ~cdev->private->imask;

		sch->vpm &= ~cdev->private->imask;

		cdev->private->imask >>= 1;

		cdev->private->iretry = 5;

		__ccw_device_verify_start(cdev);

		break;
@@ -463,19 +469,17 @@ ccw_device_verify_start(struct ccw_device *cdev) 
	struct subchannel *sch = to_subchannel(cdev->dev.parent);



	cdev->private->flags.pgid_single = 0;

	cdev->private->imask = 0x80;

	cdev->private->iretry = 5;

	/*

	 * Update sch->lpm with current values to catch paths becoming

	 * available again.

	 */



	/* Start with empty vpm. */

	sch->vpm = 0;



	/* Get current pam. */

	if (stsch(sch->schid, &sch->schib)) {

		ccw_device_verify_done(cdev, -ENODEV);

		return;

	}

	sch->lpm = sch->schib.pmcw.pim &

		sch->schib.pmcw.pam &

		sch->schib.pmcw.pom &

		sch->opm;

	__ccw_device_verify_start(cdev);

}
@@ -524,7 +528,6 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event) 
	switch (ret) {

	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */

	case 0:			/* disband successful. */

		sch->vpm = 0;

		ccw_device_disband_done(cdev, ret);

		break;

	case -EOPNOTSUPP: