[net-next-2.6.git] / drivers / s390 / cio / device_pgid.c

/*
 * drivers/s390/cio/device_pgid.c
 *
 *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
 *			 IBM Corporation
 *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 * Path Group ID functions.
 */

#include <linux/module.h>
#include <linux/init.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/delay.h>
#include <asm/lowcore.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"

/*
 * Helper function called from interrupt context to decide whether an
 * operation should be tried again.
 */
static int __ccw_device_should_retry(struct scsw *scsw)
{
	/* CC is only valid if start function bit is set. */
	if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
		return 1;
	/* No more activity. For sense and set PGID we stubbornly try again. */
	if (!scsw->actl)
		return 1;
	return 0;
}

/*
 * Start Sense Path Group ID helper function. Used in ccw_device_recog
 * and ccw_device_sense_pgid.
 */
static int
__ccw_device_sense_pgid_start(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct ccw1 *ccw;
	int ret;
	int i;

	sch = to_subchannel(cdev->dev.parent);
	/* Return if we already checked on all paths. */
	if (cdev->private->imask == 0)
		return (sch->lpm == 0) ? -ENODEV : -EACCES;
	i = 8 - ffs(cdev->private->imask);

	/* Setup sense path group id channel program. */
	ccw = cdev->private->iccws;
	ccw->cmd_code = CCW_CMD_SENSE_PGID;
	ccw->count = sizeof (struct pgid);
	ccw->flags = CCW_FLAG_SLI;

	/* Reset device status. */
	memset(&cdev->private->irb, 0, sizeof(struct irb));
	/* Try on every path. */
	ret = -ENODEV;
	while (cdev->private->imask != 0) {
		/* Try every path multiple times. */
		ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
		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)
				return ret;
			CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
				      "0.%x.%04x, lpm %02X, became 'not "
				      "operational'\n",
				      cdev->private->devno, sch->schid.ssid,
				      sch->schid.sch_no, cdev->private->imask);

		}
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		i++;
	}

	return ret;
}

void
ccw_device_sense_pgid_start(struct ccw_device *cdev)
{
	int ret;

	cdev->private->state = DEV_STATE_SENSE_PGID;
	cdev->private->imask = 0x80;
	cdev->private->iretry = 5;
	memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
	ret = __ccw_device_sense_pgid_start(cdev);
	if (ret && ret != -EBUSY)
		ccw_device_sense_pgid_done(cdev, ret);
}

/*
 * Called from interrupt context to check if a valid answer
 * to Sense Path Group ID was received.
 */
static int
__ccw_device_check_sense_pgid(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct irb *irb;
	int i;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
		return -ETIME;
	if (irb->esw.esw0.erw.cons &&
	    (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
		/*
		 * If the device doesn't support the Sense Path Group ID
		 *  command further retries wouldn't help ...
		 */
		return -EOPNOTSUPP;
	}
	if (irb->esw.esw0.erw.cons) {
		CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
			      "lpum %02X, cnt %02d, sns : "
			      "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
			      cdev->private->ssid, cdev->private->devno,
			      irb->esw.esw0.sublog.lpum,
			      irb->esw.esw0.erw.scnt,
			      irb->ecw[0], irb->ecw[1],
			      irb->ecw[2], irb->ecw[3],
			      irb->ecw[4], irb->ecw[5],
			      irb->ecw[6], irb->ecw[7]);
		return -EAGAIN;
	}
	if (irb->scsw.cc == 3) {
		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
			      " lpm %02X, became 'not operational'\n",
			      cdev->private->devno, sch->schid.ssid,
			      sch->schid.sch_no, sch->orb.lpm);
		return -EACCES;
	}
	i = 8 - ffs(cdev->private->imask);
	if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
			      "is reserved by someone else\n",
			      cdev->private->devno, sch->schid.ssid,
			      sch->schid.sch_no);
		return -EUSERS;
	}
	return 0;
}

/*
 * Got interrupt for Sense Path Group ID.
 */
void
ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;
	struct irb *irb;
	int ret;

	irb = (struct irb *) __LC_IRB;

	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (__ccw_device_should_retry(&irb->scsw)) {
			ret = __ccw_device_sense_pgid_start(cdev);
			if (ret && ret != -EBUSY)
				ccw_device_sense_pgid_done(cdev, ret);
		}
		return;
	}
	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
		return;
	sch = to_subchannel(cdev->dev.parent);
	ret = __ccw_device_check_sense_pgid(cdev);
	memset(&cdev->private->irb, 0, sizeof(struct irb));
	switch (ret) {
	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
	case -EOPNOTSUPP:	/* Sense Path Group ID not supported */
		ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
		break;
	case -ETIME:		/* Sense path group id stopped by timeout. */
		ccw_device_sense_pgid_done(cdev, -ETIME);
		break;
	case -EACCES:		/* channel is not operational. */
		sch->lpm &= ~cdev->private->imask;
		/* Fall through. */
	case 0:			/* Sense Path Group ID successful. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		/* Fall through. */
	case -EAGAIN:		/* Try again. */
		ret = __ccw_device_sense_pgid_start(cdev);
		if (ret != 0 && ret != -EBUSY)
			ccw_device_sense_pgid_done(cdev, ret);
		break;
	case -EUSERS:		/* device is reserved for someone else. */
		ccw_device_sense_pgid_done(cdev, -EUSERS);
		break;
	}
}

/*
 * Path Group ID helper function.
 */
static int
__ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
{
	struct subchannel *sch;
	struct ccw1 *ccw;
	int ret;

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

	/* Setup sense path group id channel program. */
	cdev->private->pgid[0].inf.fc = func;
	ccw = cdev->private->iccws;
	if (!cdev->private->flags.pgid_single) {
		cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
		ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
		ccw->cda = 0;
		ccw->count = 0;
		ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
		ccw++;
	} else
		cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;

	ccw->cmd_code = CCW_CMD_SET_PGID;
	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
	ccw->count = sizeof (struct pgid);
	ccw->flags = CCW_FLAG_SLI;

	/* Reset device status. */
	memset(&cdev->private->irb, 0, sizeof(struct irb));

	/* Try multiple times. */
	ret = -EACCES;
	if (cdev->private->iretry > 0) {
		cdev->private->iretry--;
		ret = cio_start (sch, cdev->private->iccws,
				 cdev->private->imask);
		/* We expect an interrupt in case of success or busy
		 * indication. */
		if ((ret == 0) || (ret == -EBUSY))
			return ret;
	}
	/* 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,
		      sch->schid.sch_no, cdev->private->imask);
	return ret;
}

/*
 * Helper function to send a nop ccw down a path.
 */
static int __ccw_device_do_nop(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct ccw1 *ccw;
	int ret;

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

	/* Setup nop channel program. */
	ccw = cdev->private->iccws;
	ccw->cmd_code = CCW_CMD_NOOP;
	ccw->cda = 0;
	ccw->count = 0;
	ccw->flags = CCW_FLAG_SLI;

	/* Reset device status. */
	memset(&cdev->private->irb, 0, sizeof(struct irb));

	/* Try multiple times. */
	ret = -EACCES;
	if (cdev->private->iretry > 0) {
		cdev->private->iretry--;
		ret = cio_start (sch, cdev->private->iccws,
				 cdev->private->imask);
		/* We expect an interrupt in case of success or busy
		 * indication. */
		if ((ret == 0) || (ret == -EBUSY))
			return ret;
	}
	/* 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,
		      sch->schid.sch_no, cdev->private->imask);
	return ret;
}


/*
 * Called from interrupt context to check if a valid answer
 * to Set Path Group ID was received.
 */
static int
__ccw_device_check_pgid(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct irb *irb;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
		return -ETIME;
	if (irb->esw.esw0.erw.cons) {
		if (irb->ecw[0] & SNS0_CMD_REJECT)
			return -EOPNOTSUPP;
		/* Hmm, whatever happened, try again. */
		CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
			      "cnt %02d, "
			      "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
			      cdev->private->ssid,
			      cdev->private->devno, irb->esw.esw0.erw.scnt,
			      irb->ecw[0], irb->ecw[1],
			      irb->ecw[2], irb->ecw[3],
			      irb->ecw[4], irb->ecw[5],
			      irb->ecw[6], irb->ecw[7]);
		return -EAGAIN;
	}
	if (irb->scsw.cc == 3) {
		CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
			      " lpm %02X, became 'not operational'\n",
			      cdev->private->devno, sch->schid.ssid,
			      sch->schid.sch_no, cdev->private->imask);
		return -EACCES;
	}
	return 0;
}

/*
 * Called from interrupt context to check the path status after a nop has
 * been send.
 */
static int __ccw_device_check_nop(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct irb *irb;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
		return -ETIME;
	if (irb->scsw.cc == 3) {
		CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
			      " lpm %02X, became 'not operational'\n",
			      cdev->private->devno, sch->schid.ssid,
			      sch->schid.sch_no, cdev->private->imask);
		return -EACCES;
	}
	return 0;
}

static void
__ccw_device_verify_start(struct ccw_device *cdev)
{
	struct subchannel *sch;
	__u8 func;
	int ret;

	sch = to_subchannel(cdev->dev.parent);
	/* 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) {
			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;
		/* Permanent path failure, try next. */
	}
	/* Done with all paths. */
	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
}
		
/*
 * Got interrupt for Set Path Group ID.
 */
void
ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;
	struct irb *irb;
	int ret;

	irb = (struct irb *) __LC_IRB;

	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (__ccw_device_should_retry(&irb->scsw))
			__ccw_device_verify_start(cdev);
		return;
	}
	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
		return;
	sch = to_subchannel(cdev->dev.parent);
	if (cdev->private->options.pgroup)
		ret = __ccw_device_check_pgid(cdev);
	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:
		/* 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;
	case -EOPNOTSUPP:
		/*
		 * One of those strange devices which claim to be able
		 * to do multipathing but not for Set Path Group ID.
		 */
		if (cdev->private->flags.pgid_single)
			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);
		break;
	case -ETIME:		/* Set path group id stopped by timeout. */
		ccw_device_verify_done(cdev, -ETIME);
		break;
	case -EACCES:		/* channel is not operational. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		__ccw_device_verify_start(cdev);
		break;
	}
}

void
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;

	/* Start with empty vpm. */
	sch->vpm = 0;

	/* Get current pam. */
	if (stsch(sch->schid, &sch->schib)) {
		ccw_device_verify_done(cdev, -ENODEV);
		return;
	}
	__ccw_device_verify_start(cdev);
}

static void
__ccw_device_disband_start(struct ccw_device *cdev)
{
	struct subchannel *sch;
	int ret;

	sch = to_subchannel(cdev->dev.parent);
	while (cdev->private->imask != 0) {
		if (sch->lpm & cdev->private->imask) {
			ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
			if (ret == 0)
				return;
		}
		cdev->private->iretry = 5;
		cdev->private->imask >>= 1;
	}
	ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
}

/*
 * Got interrupt for Unset Path Group ID.
 */
void
ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;
	struct irb *irb;
	int ret;

	irb = (struct irb *) __LC_IRB;

	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (__ccw_device_should_retry(&irb->scsw))
			__ccw_device_disband_start(cdev);
		return;
	}
	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
		return;
	sch = to_subchannel(cdev->dev.parent);
	ret = __ccw_device_check_pgid(cdev);
	memset(&cdev->private->irb, 0, sizeof(struct irb));
	switch (ret) {
	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	case 0:			/* disband successful. */
		ccw_device_disband_done(cdev, ret);
		break;
	case -EOPNOTSUPP:
		/*
		 * One of those strange devices which claim to be able
		 * to do multipathing but not for Unset Path Group ID.
		 */
		cdev->private->flags.pgid_single = 1;
		/* fall through. */
	case -EAGAIN:		/* Try again. */
		__ccw_device_disband_start(cdev);
		break;
	case -ETIME:		/* Set path group id stopped by timeout. */
		ccw_device_disband_done(cdev, -ETIME);
		break;
	case -EACCES:		/* channel is not operational. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		__ccw_device_disband_start(cdev);
		break;
	}
}

void
ccw_device_disband_start(struct ccw_device *cdev)
{
	cdev->private->flags.pgid_single = 0;
	cdev->private->iretry = 5;
	cdev->private->imask = 0x80;
	__ccw_device_disband_start(cdev);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/s390/cio/device_pgid.c
	3	*
	4	* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
	5	* IBM Corporation
4ce3b30c	6	* Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
1da177e4 LT	7	* Martin Schwidefsky (schwidefsky@de.ibm.com)
	8	*
	9	* Path Group ID functions.
	10	*/
	11
1da177e4 LT	12	#include <linux/module.h>
	13	#include <linux/init.h>
	14
	15	#include <asm/ccwdev.h>
	16	#include <asm/cio.h>
	17	#include <asm/delay.h>
	18	#include <asm/lowcore.h>
	19
	20	#include "cio.h"
	21	#include "cio_debug.h"
	22	#include "css.h"
	23	#include "device.h"
6810a2bc	24	#include "ioasm.h"
1da177e4	25
7b7db1b5 SB	26	/*
	27	* Helper function called from interrupt context to decide whether an
	28	* operation should be tried again.
	29	*/
	30	static int __ccw_device_should_retry(struct scsw *scsw)
	31	{
	32	/* CC is only valid if start function bit is set. */
	33	if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
	34	return 1;
	35	/* No more activity. For sense and set PGID we stubbornly try again. */
	36	if (!scsw->actl)
	37	return 1;
	38	return 0;
	39	}
	40
1da177e4 LT	41	/*
	42	* Start Sense Path Group ID helper function. Used in ccw_device_recog
	43	* and ccw_device_sense_pgid.
	44	*/
	45	static int
	46	__ccw_device_sense_pgid_start(struct ccw_device *cdev)
	47	{
	48	struct subchannel *sch;
	49	struct ccw1 *ccw;
	50	int ret;
7e560814	51	int i;
1da177e4 LT	52
1da177e4 LT	53	sch = to_subchannel(cdev->dev.parent);
7e560814 CH	54	/* Return if we already checked on all paths. */
	55	if (cdev->private->imask == 0)
	56	return (sch->lpm == 0) ? -ENODEV : -EACCES;
	57	i = 8 - ffs(cdev->private->imask);
	58
1da177e4 LT	59	/* Setup sense path group id channel program. */
	60	ccw = cdev->private->iccws;
	61	ccw->cmd_code = CCW_CMD_SENSE_PGID;
1da177e4 LT	62	ccw->count = sizeof (struct pgid);
	63	ccw->flags = CCW_FLAG_SLI;
	64
	65	/* Reset device status. */
	66	memset(&cdev->private->irb, 0, sizeof(struct irb));
	67	/* Try on every path. */
	68	ret = -ENODEV;
	69	while (cdev->private->imask != 0) {
	70	/* Try every path multiple times. */
7e560814	71	ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
1da177e4 LT	72	if (cdev->private->iretry > 0) {
	73	cdev->private->iretry--;
	74	ret = cio_start (sch, cdev->private->iccws,
	75	cdev->private->imask);
	76	/* ret is 0, -EBUSY, -EACCES or -ENODEV */
	77	if (ret != -EACCES)
	78	return ret;
	79	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
fb6958a5	80	"0.%x.%04x, lpm %02X, became 'not "
1da177e4	81	"operational'\n",
fb6958a5 CH	82	cdev->private->devno, sch->schid.ssid,
fb6958a5 CH	83	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	84
	85	}
	86	cdev->private->imask >>= 1;
	87	cdev->private->iretry = 5;
7e560814	88	i++;
1da177e4	89	}
7e560814	90
1da177e4 LT	91	return ret;
	92	}
	93
	94	void
	95	ccw_device_sense_pgid_start(struct ccw_device *cdev)
	96	{
	97	int ret;
	98
	99	cdev->private->state = DEV_STATE_SENSE_PGID;
	100	cdev->private->imask = 0x80;
	101	cdev->private->iretry = 5;
7e560814	102	memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
1da177e4 LT	103	ret = __ccw_device_sense_pgid_start(cdev);
	104	if (ret && ret != -EBUSY)
	105	ccw_device_sense_pgid_done(cdev, ret);
	106	}
	107
	108	/*
	109	* Called from interrupt context to check if a valid answer
	110	* to Sense Path Group ID was received.
	111	*/
	112	static int
	113	__ccw_device_check_sense_pgid(struct ccw_device *cdev)
	114	{
	115	struct subchannel *sch;
	116	struct irb *irb;
7e560814	117	int i;
1da177e4 LT	118
	119	sch = to_subchannel(cdev->dev.parent);
	120	irb = &cdev->private->irb;
	121	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC))
	122	return -ETIME;
	123	if (irb->esw.esw0.erw.cons &&
	124	(irb->ecw[0]&(SNS0_CMD_REJECT\|SNS0_INTERVENTION_REQ))) {
	125	/*
	126	* If the device doesn't support the Sense Path Group ID
	127	* command further retries wouldn't help ...
	128	*/
	129	return -EOPNOTSUPP;
	130	}
	131	if (irb->esw.esw0.erw.cons) {
fb6958a5	132	CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
1da177e4 LT	133	"lpum %02X, cnt %02d, sns : "
1da177e4 LT	134	"%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
fb6958a5	135	cdev->private->ssid, cdev->private->devno,
1da177e4 LT	136	irb->esw.esw0.sublog.lpum,
	137	irb->esw.esw0.erw.scnt,
	138	irb->ecw[0], irb->ecw[1],
	139	irb->ecw[2], irb->ecw[3],
	140	irb->ecw[4], irb->ecw[5],
	141	irb->ecw[6], irb->ecw[7]);
	142	return -EAGAIN;
	143	}
	144	if (irb->scsw.cc == 3) {
fb6958a5 CH	145	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
	146	" lpm %02X, became 'not operational'\n",
	147	cdev->private->devno, sch->schid.ssid,
	148	sch->schid.sch_no, sch->orb.lpm);
1da177e4 LT	149	return -EACCES;
1da177e4 LT	150	}
7e560814 CH	151	i = 8 - ffs(cdev->private->imask);
7e560814 CH	152	if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
fb6958a5	153	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
1da177e4	154	"is reserved by someone else\n",
fb6958a5 CH	155	cdev->private->devno, sch->schid.ssid,
fb6958a5 CH	156	sch->schid.sch_no);
1da177e4 LT	157	return -EUSERS;
	158	}
	159	return 0;
	160	}
	161
	162	/*
	163	* Got interrupt for Sense Path Group ID.
	164	*/
	165	void
	166	ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
	167	{
	168	struct subchannel *sch;
	169	struct irb *irb;
	170	int ret;
	171
	172	irb = (struct irb *) __LC_IRB;
7b7db1b5	173
1da177e4 LT	174	if (irb->scsw.stctl ==
1da177e4 LT	175	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	176	if (__ccw_device_should_retry(&irb->scsw)) {
1da177e4 LT	177	ret = __ccw_device_sense_pgid_start(cdev);
	178	if (ret && ret != -EBUSY)
	179	ccw_device_sense_pgid_done(cdev, ret);
	180	}
	181	return;
	182	}
	183	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	184	return;
	185	sch = to_subchannel(cdev->dev.parent);
	186	ret = __ccw_device_check_sense_pgid(cdev);
	187	memset(&cdev->private->irb, 0, sizeof(struct irb));
	188	switch (ret) {
	189	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
1da177e4 LT	190	case -EOPNOTSUPP: /* Sense Path Group ID not supported */
	191	ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
	192	break;
	193	case -ETIME: /* Sense path group id stopped by timeout. */
	194	ccw_device_sense_pgid_done(cdev, -ETIME);
	195	break;
	196	case -EACCES: /* channel is not operational. */
	197	sch->lpm &= ~cdev->private->imask;
7e560814 CH	198	/* Fall through. */
7e560814 CH	199	case 0: /* Sense Path Group ID successful. */
1da177e4 LT	200	cdev->private->imask >>= 1;
	201	cdev->private->iretry = 5;
	202	/* Fall through. */
	203	case -EAGAIN: /* Try again. */
	204	ret = __ccw_device_sense_pgid_start(cdev);
	205	if (ret != 0 && ret != -EBUSY)
7e560814	206	ccw_device_sense_pgid_done(cdev, ret);
1da177e4 LT	207	break;
	208	case -EUSERS: /* device is reserved for someone else. */
	209	ccw_device_sense_pgid_done(cdev, -EUSERS);
	210	break;
	211	}
	212	}
	213
	214	/*
	215	* Path Group ID helper function.
	216	*/
	217	static int
	218	__ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
	219	{
	220	struct subchannel *sch;
	221	struct ccw1 *ccw;
	222	int ret;
	223
	224	sch = to_subchannel(cdev->dev.parent);
	225
	226	/* Setup sense path group id channel program. */
7e560814	227	cdev->private->pgid[0].inf.fc = func;
1da177e4 LT	228	ccw = cdev->private->iccws;
1da177e4 LT	229	if (!cdev->private->flags.pgid_single) {
7e560814	230	cdev->private->pgid[0].inf.fc \|= SPID_FUNC_MULTI_PATH;
1da177e4 LT	231	ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
	232	ccw->cda = 0;
	233	ccw->count = 0;
	234	ccw->flags = CCW_FLAG_SLI \| CCW_FLAG_CC;
	235	ccw++;
	236	} else
7e560814	237	cdev->private->pgid[0].inf.fc \|= SPID_FUNC_SINGLE_PATH;
1da177e4 LT	238
1da177e4 LT	239	ccw->cmd_code = CCW_CMD_SET_PGID;
7e560814	240	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
1da177e4 LT	241	ccw->count = sizeof (struct pgid);
	242	ccw->flags = CCW_FLAG_SLI;
	243
	244	/* Reset device status. */
	245	memset(&cdev->private->irb, 0, sizeof(struct irb));
	246
	247	/* Try multiple times. */
28bdc6f6	248	ret = -EACCES;
1da177e4 LT	249	if (cdev->private->iretry > 0) {
	250	cdev->private->iretry--;
	251	ret = cio_start (sch, cdev->private->iccws,
	252	cdev->private->imask);
28bdc6f6 PO	253	/* We expect an interrupt in case of success or busy
	254	* indication. */
	255	if ((ret == 0) \|\| (ret == -EBUSY))
1da177e4 LT	256	return ret;
1da177e4 LT	257	}
28bdc6f6	258	/* PGID command failed on this path. */
1da177e4	259	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
fb6958a5 CH	260	"0.%x.%04x, lpm %02X, became 'not operational'\n",
	261	cdev->private->devno, sch->schid.ssid,
	262	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	263	return ret;
	264	}
	265
7e560814 CH	266	/*
	267	* Helper function to send a nop ccw down a path.
	268	*/
	269	static int __ccw_device_do_nop(struct ccw_device *cdev)
	270	{
	271	struct subchannel *sch;
	272	struct ccw1 *ccw;
	273	int ret;
	274
	275	sch = to_subchannel(cdev->dev.parent);
	276
	277	/* Setup nop channel program. */
	278	ccw = cdev->private->iccws;
	279	ccw->cmd_code = CCW_CMD_NOOP;
	280	ccw->cda = 0;
	281	ccw->count = 0;
	282	ccw->flags = CCW_FLAG_SLI;
	283
	284	/* Reset device status. */
	285	memset(&cdev->private->irb, 0, sizeof(struct irb));
	286
	287	/* Try multiple times. */
28bdc6f6	288	ret = -EACCES;
7e560814 CH	289	if (cdev->private->iretry > 0) {
	290	cdev->private->iretry--;
	291	ret = cio_start (sch, cdev->private->iccws,
	292	cdev->private->imask);
28bdc6f6 PO	293	/* We expect an interrupt in case of success or busy
	294	* indication. */
	295	if ((ret == 0) \|\| (ret == -EBUSY))
7e560814 CH	296	return ret;
7e560814 CH	297	}
28bdc6f6	298	/* nop command failed on this path. */
7e560814 CH	299	CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
	300	"0.%x.%04x, lpm %02X, became 'not operational'\n",
	301	cdev->private->devno, sch->schid.ssid,
	302	sch->schid.sch_no, cdev->private->imask);
	303	return ret;
	304	}
	305
	306
1da177e4 LT	307	/*
	308	* Called from interrupt context to check if a valid answer
	309	* to Set Path Group ID was received.
	310	*/
	311	static int
	312	__ccw_device_check_pgid(struct ccw_device *cdev)
	313	{
	314	struct subchannel *sch;
	315	struct irb *irb;
	316
	317	sch = to_subchannel(cdev->dev.parent);
	318	irb = &cdev->private->irb;
	319	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC))
	320	return -ETIME;
	321	if (irb->esw.esw0.erw.cons) {
	322	if (irb->ecw[0] & SNS0_CMD_REJECT)
	323	return -EOPNOTSUPP;
	324	/* Hmm, whatever happened, try again. */
fb6958a5 CH	325	CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
fb6958a5 CH	326	"cnt %02d, "
1da177e4	327	"sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
fb6958a5	328	cdev->private->ssid,
1da177e4 LT	329	cdev->private->devno, irb->esw.esw0.erw.scnt,
	330	irb->ecw[0], irb->ecw[1],
	331	irb->ecw[2], irb->ecw[3],
	332	irb->ecw[4], irb->ecw[5],
	333	irb->ecw[6], irb->ecw[7]);
	334	return -EAGAIN;
	335	}
	336	if (irb->scsw.cc == 3) {
fb6958a5 CH	337	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
	338	" lpm %02X, became 'not operational'\n",
	339	cdev->private->devno, sch->schid.ssid,
	340	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	341	return -EACCES;
	342	}
	343	return 0;
	344	}
	345
7e560814 CH	346	/*
	347	* Called from interrupt context to check the path status after a nop has
	348	* been send.
	349	*/
	350	static int __ccw_device_check_nop(struct ccw_device *cdev)
	351	{
	352	struct subchannel *sch;
	353	struct irb *irb;
	354
	355	sch = to_subchannel(cdev->dev.parent);
	356	irb = &cdev->private->irb;
	357	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC))
	358	return -ETIME;
	359	if (irb->scsw.cc == 3) {
	360	CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
	361	" lpm %02X, became 'not operational'\n",
	362	cdev->private->devno, sch->schid.ssid,
	363	sch->schid.sch_no, cdev->private->imask);
	364	return -EACCES;
	365	}
	366	return 0;
	367	}
	368
1da177e4 LT	369	static void
	370	__ccw_device_verify_start(struct ccw_device *cdev)
	371	{
	372	struct subchannel *sch;
28bdc6f6	373	__u8 func;
1da177e4 LT	374	int ret;
	375
	376	sch = to_subchannel(cdev->dev.parent);
28bdc6f6 PO	377	/* Repeat for all paths. */
	378	for (; cdev->private->imask; cdev->private->imask >>= 1,
	379	cdev->private->iretry = 5) {
	380	if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
	381	/* Path not available, try next. */
	382	continue;
7e560814	383	if (cdev->private->options.pgroup) {
28bdc6f6 PO	384	if (sch->opm & cdev->private->imask)
	385	func = SPID_FUNC_ESTABLISH;
	386	else
	387	func = SPID_FUNC_RESIGN;
7e560814 CH	388	ret = __ccw_device_do_pgid(cdev, func);
	389	} else
	390	ret = __ccw_device_do_nop(cdev);
28bdc6f6 PO	391	/* We expect an interrupt in case of success or busy
28bdc6f6 PO	392	* indication. */
1da177e4 LT	393	if (ret == 0 \|\| ret == -EBUSY)
1da177e4 LT	394	return;
28bdc6f6	395	/* Permanent path failure, try next. */
1da177e4	396	}
28bdc6f6 PO	397	/* Done with all paths. */
28bdc6f6 PO	398	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
1da177e4 LT	399	}
	400
	401	/*
	402	* Got interrupt for Set Path Group ID.
	403	*/
	404	void
	405	ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
	406	{
	407	struct subchannel *sch;
	408	struct irb *irb;
	409	int ret;
	410
	411	irb = (struct irb *) __LC_IRB;
7b7db1b5	412
1da177e4 LT	413	if (irb->scsw.stctl ==
1da177e4 LT	414	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	415	if (__ccw_device_should_retry(&irb->scsw))
1da177e4 LT	416	__ccw_device_verify_start(cdev);
	417	return;
	418	}
	419	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	420	return;
	421	sch = to_subchannel(cdev->dev.parent);
7e560814 CH	422	if (cdev->private->options.pgroup)
	423	ret = __ccw_device_check_pgid(cdev);
	424	else
	425	ret = __ccw_device_check_nop(cdev);
1da177e4	426	memset(&cdev->private->irb, 0, sizeof(struct irb));
28bdc6f6	427
1da177e4 LT	428	switch (ret) {
	429	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	430	case 0:
28bdc6f6 PO	431	/* Path verification ccw finished successfully, update lpm. */
	432	sch->vpm \|= sch->opm & cdev->private->imask;
	433	/* Go on with next path. */
	434	cdev->private->imask >>= 1;
1da177e4 LT	435	cdev->private->iretry = 5;
	436	__ccw_device_verify_start(cdev);
	437	break;
	438	case -EOPNOTSUPP:
	439	/*
	440	* One of those strange devices which claim to be able
	441	* to do multipathing but not for Set Path Group ID.
	442	*/
7e560814 CH	443	if (cdev->private->flags.pgid_single)
	444	cdev->private->options.pgroup = 0;
	445	else
	446	cdev->private->flags.pgid_single = 1;
28bdc6f6 PO	447	/* Retry */
	448	sch->vpm = 0;
	449	cdev->private->imask = 0x80;
	450	cdev->private->iretry = 5;
1da177e4 LT	451	/* fall through. */
	452	case -EAGAIN: /* Try again. */
	453	__ccw_device_verify_start(cdev);
	454	break;
	455	case -ETIME: /* Set path group id stopped by timeout. */
	456	ccw_device_verify_done(cdev, -ETIME);
	457	break;
	458	case -EACCES: /* channel is not operational. */
28bdc6f6	459	cdev->private->imask >>= 1;
1da177e4 LT	460	cdev->private->iretry = 5;
	461	__ccw_device_verify_start(cdev);
	462	break;
	463	}
	464	}
	465
	466	void
	467	ccw_device_verify_start(struct ccw_device *cdev)
	468	{
6810a2bc CH	469	struct subchannel *sch = to_subchannel(cdev->dev.parent);
6810a2bc CH	470
1da177e4	471	cdev->private->flags.pgid_single = 0;
28bdc6f6	472	cdev->private->imask = 0x80;
1da177e4	473	cdev->private->iretry = 5;
28bdc6f6 PO	474
	475	/* Start with empty vpm. */
	476	sch->vpm = 0;
	477
	478	/* Get current pam. */
a8237fc4	479	if (stsch(sch->schid, &sch->schib)) {
6810a2bc CH	480	ccw_device_verify_done(cdev, -ENODEV);
	481	return;
	482	}
1da177e4 LT	483	__ccw_device_verify_start(cdev);
	484	}
	485
	486	static void
	487	__ccw_device_disband_start(struct ccw_device *cdev)
	488	{
	489	struct subchannel *sch;
	490	int ret;
	491
	492	sch = to_subchannel(cdev->dev.parent);
	493	while (cdev->private->imask != 0) {
	494	if (sch->lpm & cdev->private->imask) {
	495	ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
	496	if (ret == 0)
	497	return;
	498	}
	499	cdev->private->iretry = 5;
	500	cdev->private->imask >>= 1;
	501	}
6d751c43	502	ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
1da177e4 LT	503	}
	504
	505	/*
	506	* Got interrupt for Unset Path Group ID.
	507	*/
	508	void
	509	ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
	510	{
	511	struct subchannel *sch;
	512	struct irb *irb;
	513	int ret;
	514
	515	irb = (struct irb *) __LC_IRB;
7b7db1b5	516
1da177e4 LT	517	if (irb->scsw.stctl ==
1da177e4 LT	518	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	519	if (__ccw_device_should_retry(&irb->scsw))
1da177e4 LT	520	__ccw_device_disband_start(cdev);
	521	return;
	522	}
	523	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	524	return;
	525	sch = to_subchannel(cdev->dev.parent);
	526	ret = __ccw_device_check_pgid(cdev);
	527	memset(&cdev->private->irb, 0, sizeof(struct irb));
	528	switch (ret) {
	529	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	530	case 0: /* disband successful. */
1da177e4 LT	531	ccw_device_disband_done(cdev, ret);
	532	break;
	533	case -EOPNOTSUPP:
	534	/*
	535	* One of those strange devices which claim to be able
	536	* to do multipathing but not for Unset Path Group ID.
	537	*/
	538	cdev->private->flags.pgid_single = 1;
	539	/* fall through. */
	540	case -EAGAIN: /* Try again. */
	541	__ccw_device_disband_start(cdev);
	542	break;
	543	case -ETIME: /* Set path group id stopped by timeout. */
	544	ccw_device_disband_done(cdev, -ETIME);
	545	break;
	546	case -EACCES: /* channel is not operational. */
	547	cdev->private->imask >>= 1;
	548	cdev->private->iretry = 5;
	549	__ccw_device_disband_start(cdev);
	550	break;
	551	}
	552	}
	553
	554	void
	555	ccw_device_disband_start(struct ccw_device *cdev)
	556	{
	557	cdev->private->flags.pgid_single = 0;
	558	cdev->private->iretry = 5;
	559	cdev->private->imask = 0x80;
	560	__ccw_device_disband_start(cdev);
	561	}