[GitHub/mt8127/android_kernel_alcatel_ttab.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"
#include "io_sch.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--;
			/* Reset internal retry indication. */
			cdev->private->flags.intretry = 0;
			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->dev_id.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;

	/* Set a timeout of 60s */
	ccw_device_set_timeout(cdev, 60*HZ);

	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)) {
		/* Retry Sense PGID if requested. */
		if (cdev->private->flags.intretry) {
			cdev->private->flags.intretry = 0;
			return -EAGAIN;
		}
		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->dev_id.ssid,
			      cdev->private->dev_id.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) {
		u8 lpm;

		lpm = to_io_private(sch)->orb.lpm;
		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
			      " lpm %02X, became 'not operational'\n",
			      cdev->private->dev_id.devno, sch->schid.ssid,
			      sch->schid.sch_no, 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->dev_id.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--;
		/* Reset internal retry indication. */
		cdev->private->flags.intretry = 0;
		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->dev_id.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--;
		/* Reset internal retry indication. */
		cdev->private->flags.intretry = 0;
		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->dev_id.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)) {
		/* Retry Set PGID if requested. */
		if (cdev->private->flags.intretry) {
			cdev->private->flags.intretry = 0;
			return -EAGAIN;
		}
		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->dev_id.ssid,
			      cdev->private->dev_id.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->dev_id.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)) {
		/* Retry NOP if requested. */
		if (cdev->private->flags.intretry) {
			cdev->private->flags.intretry = 0;
			return -EAGAIN;
		}
		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->dev_id.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;
	}
	/* After 60s path verification is considered to have failed. */
	ccw_device_set_timeout(cdev, 60*HZ);
	__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)
{
	/* After 60s disbanding is considered to have failed. */
	ccw_device_set_timeout(cdev, 60*HZ);

	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"
cd6b4f27	25	#include "io_sch.h"
1da177e4	26
7b7db1b5 SB	27	/*
	28	* Helper function called from interrupt context to decide whether an
	29	* operation should be tried again.
	30	*/
	31	static int __ccw_device_should_retry(struct scsw *scsw)
	32	{
	33	/* CC is only valid if start function bit is set. */
	34	if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
	35	return 1;
	36	/* No more activity. For sense and set PGID we stubbornly try again. */
	37	if (!scsw->actl)
	38	return 1;
	39	return 0;
	40	}
	41
1da177e4 LT	42	/*
	43	* Start Sense Path Group ID helper function. Used in ccw_device_recog
	44	* and ccw_device_sense_pgid.
	45	*/
	46	static int
	47	__ccw_device_sense_pgid_start(struct ccw_device *cdev)
	48	{
	49	struct subchannel *sch;
	50	struct ccw1 *ccw;
	51	int ret;
7e560814	52	int i;
1da177e4 LT	53
1da177e4 LT	54	sch = to_subchannel(cdev->dev.parent);
7e560814 CH	55	/* Return if we already checked on all paths. */
	56	if (cdev->private->imask == 0)
	57	return (sch->lpm == 0) ? -ENODEV : -EACCES;
	58	i = 8 - ffs(cdev->private->imask);
	59
1da177e4 LT	60	/* Setup sense path group id channel program. */
	61	ccw = cdev->private->iccws;
	62	ccw->cmd_code = CCW_CMD_SENSE_PGID;
1da177e4 LT	63	ccw->count = sizeof (struct pgid);
	64	ccw->flags = CCW_FLAG_SLI;
	65
	66	/* Reset device status. */
	67	memset(&cdev->private->irb, 0, sizeof(struct irb));
	68	/* Try on every path. */
	69	ret = -ENODEV;
	70	while (cdev->private->imask != 0) {
	71	/* Try every path multiple times. */
7e560814	72	ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
1da177e4 LT	73	if (cdev->private->iretry > 0) {
1da177e4 LT	74	cdev->private->iretry--;
d23861ff CH	75	/* Reset internal retry indication. */
d23861ff CH	76	cdev->private->flags.intretry = 0;
1da177e4 LT	77	ret = cio_start (sch, cdev->private->iccws,
	78	cdev->private->imask);
	79	/* ret is 0, -EBUSY, -EACCES or -ENODEV */
	80	if (ret != -EACCES)
	81	return ret;
	82	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
fb6958a5	83	"0.%x.%04x, lpm %02X, became 'not "
1da177e4	84	"operational'\n",
78964268 CH	85	cdev->private->dev_id.devno,
78964268 CH	86	sch->schid.ssid,
fb6958a5	87	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	88
	89	}
	90	cdev->private->imask >>= 1;
	91	cdev->private->iretry = 5;
7e560814	92	i++;
1da177e4	93	}
7e560814	94
1da177e4 LT	95	return ret;
	96	}
	97
	98	void
	99	ccw_device_sense_pgid_start(struct ccw_device *cdev)
	100	{
	101	int ret;
	102
f1ee3281 CH	103	/* Set a timeout of 60s */
	104	ccw_device_set_timeout(cdev, 60*HZ);
	105
1da177e4 LT	106	cdev->private->state = DEV_STATE_SENSE_PGID;
	107	cdev->private->imask = 0x80;
	108	cdev->private->iretry = 5;
7e560814	109	memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
1da177e4 LT	110	ret = __ccw_device_sense_pgid_start(cdev);
	111	if (ret && ret != -EBUSY)
	112	ccw_device_sense_pgid_done(cdev, ret);
	113	}
	114
	115	/*
	116	* Called from interrupt context to check if a valid answer
	117	* to Sense Path Group ID was received.
	118	*/
	119	static int
	120	__ccw_device_check_sense_pgid(struct ccw_device *cdev)
	121	{
	122	struct subchannel *sch;
	123	struct irb *irb;
7e560814	124	int i;
1da177e4 LT	125
	126	sch = to_subchannel(cdev->dev.parent);
	127	irb = &cdev->private->irb;
d23861ff CH	128	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC)) {
	129	/* Retry Sense PGID if requested. */
	130	if (cdev->private->flags.intretry) {
	131	cdev->private->flags.intretry = 0;
	132	return -EAGAIN;
	133	}
1da177e4	134	return -ETIME;
d23861ff	135	}
1da177e4 LT	136	if (irb->esw.esw0.erw.cons &&
	137	(irb->ecw[0]&(SNS0_CMD_REJECT\|SNS0_INTERVENTION_REQ))) {
	138	/*
	139	* If the device doesn't support the Sense Path Group ID
	140	* command further retries wouldn't help ...
	141	*/
	142	return -EOPNOTSUPP;
	143	}
	144	if (irb->esw.esw0.erw.cons) {
fb6958a5	145	CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
1da177e4 LT	146	"lpum %02X, cnt %02d, sns : "
1da177e4 LT	147	"%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
78964268 CH	148	cdev->private->dev_id.ssid,
78964268 CH	149	cdev->private->dev_id.devno,
1da177e4 LT	150	irb->esw.esw0.sublog.lpum,
	151	irb->esw.esw0.erw.scnt,
	152	irb->ecw[0], irb->ecw[1],
	153	irb->ecw[2], irb->ecw[3],
	154	irb->ecw[4], irb->ecw[5],
	155	irb->ecw[6], irb->ecw[7]);
	156	return -EAGAIN;
	157	}
	158	if (irb->scsw.cc == 3) {
cd6b4f27 CH	159	u8 lpm;
	160
	161	lpm = to_io_private(sch)->orb.lpm;
fb6958a5 CH	162	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
fb6958a5 CH	163	" lpm %02X, became 'not operational'\n",
78964268	164	cdev->private->dev_id.devno, sch->schid.ssid,
cd6b4f27	165	sch->schid.sch_no, lpm);
1da177e4 LT	166	return -EACCES;
1da177e4 LT	167	}
7e560814 CH	168	i = 8 - ffs(cdev->private->imask);
7e560814 CH	169	if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
fb6958a5	170	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
1da177e4	171	"is reserved by someone else\n",
78964268	172	cdev->private->dev_id.devno, sch->schid.ssid,
fb6958a5	173	sch->schid.sch_no);
1da177e4 LT	174	return -EUSERS;
	175	}
	176	return 0;
	177	}
	178
	179	/*
	180	* Got interrupt for Sense Path Group ID.
	181	*/
	182	void
	183	ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
	184	{
	185	struct subchannel *sch;
	186	struct irb *irb;
	187	int ret;
	188
	189	irb = (struct irb *) __LC_IRB;
7b7db1b5	190
1da177e4 LT	191	if (irb->scsw.stctl ==
1da177e4 LT	192	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	193	if (__ccw_device_should_retry(&irb->scsw)) {
1da177e4 LT	194	ret = __ccw_device_sense_pgid_start(cdev);
	195	if (ret && ret != -EBUSY)
	196	ccw_device_sense_pgid_done(cdev, ret);
	197	}
	198	return;
	199	}
	200	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	201	return;
	202	sch = to_subchannel(cdev->dev.parent);
	203	ret = __ccw_device_check_sense_pgid(cdev);
	204	memset(&cdev->private->irb, 0, sizeof(struct irb));
	205	switch (ret) {
	206	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
1da177e4 LT	207	case -EOPNOTSUPP: /* Sense Path Group ID not supported */
	208	ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
	209	break;
	210	case -ETIME: /* Sense path group id stopped by timeout. */
	211	ccw_device_sense_pgid_done(cdev, -ETIME);
	212	break;
	213	case -EACCES: /* channel is not operational. */
	214	sch->lpm &= ~cdev->private->imask;
7e560814 CH	215	/* Fall through. */
7e560814 CH	216	case 0: /* Sense Path Group ID successful. */
1da177e4 LT	217	cdev->private->imask >>= 1;
	218	cdev->private->iretry = 5;
	219	/* Fall through. */
	220	case -EAGAIN: /* Try again. */
	221	ret = __ccw_device_sense_pgid_start(cdev);
	222	if (ret != 0 && ret != -EBUSY)
7e560814	223	ccw_device_sense_pgid_done(cdev, ret);
1da177e4 LT	224	break;
	225	case -EUSERS: /* device is reserved for someone else. */
	226	ccw_device_sense_pgid_done(cdev, -EUSERS);
	227	break;
	228	}
	229	}
	230
	231	/*
	232	* Path Group ID helper function.
	233	*/
	234	static int
	235	__ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
	236	{
	237	struct subchannel *sch;
	238	struct ccw1 *ccw;
	239	int ret;
	240
	241	sch = to_subchannel(cdev->dev.parent);
	242
	243	/* Setup sense path group id channel program. */
7e560814	244	cdev->private->pgid[0].inf.fc = func;
1da177e4 LT	245	ccw = cdev->private->iccws;
1da177e4 LT	246	if (!cdev->private->flags.pgid_single) {
7e560814	247	cdev->private->pgid[0].inf.fc \|= SPID_FUNC_MULTI_PATH;
1da177e4 LT	248	ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
	249	ccw->cda = 0;
	250	ccw->count = 0;
	251	ccw->flags = CCW_FLAG_SLI \| CCW_FLAG_CC;
	252	ccw++;
	253	} else
7e560814	254	cdev->private->pgid[0].inf.fc \|= SPID_FUNC_SINGLE_PATH;
1da177e4 LT	255
1da177e4 LT	256	ccw->cmd_code = CCW_CMD_SET_PGID;
7e560814	257	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
1da177e4 LT	258	ccw->count = sizeof (struct pgid);
	259	ccw->flags = CCW_FLAG_SLI;
	260
	261	/* Reset device status. */
	262	memset(&cdev->private->irb, 0, sizeof(struct irb));
	263
	264	/* Try multiple times. */
28bdc6f6	265	ret = -EACCES;
1da177e4 LT	266	if (cdev->private->iretry > 0) {
1da177e4 LT	267	cdev->private->iretry--;
d23861ff CH	268	/* Reset internal retry indication. */
d23861ff CH	269	cdev->private->flags.intretry = 0;
1da177e4 LT	270	ret = cio_start (sch, cdev->private->iccws,
1da177e4 LT	271	cdev->private->imask);
28bdc6f6 PO	272	/* We expect an interrupt in case of success or busy
	273	* indication. */
	274	if ((ret == 0) \|\| (ret == -EBUSY))
1da177e4 LT	275	return ret;
1da177e4 LT	276	}
28bdc6f6	277	/* PGID command failed on this path. */
1da177e4	278	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
fb6958a5	279	"0.%x.%04x, lpm %02X, became 'not operational'\n",
78964268	280	cdev->private->dev_id.devno, sch->schid.ssid,
fb6958a5	281	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	282	return ret;
	283	}
	284
7e560814 CH	285	/*
	286	* Helper function to send a nop ccw down a path.
	287	*/
	288	static int __ccw_device_do_nop(struct ccw_device *cdev)
	289	{
	290	struct subchannel *sch;
	291	struct ccw1 *ccw;
	292	int ret;
	293
	294	sch = to_subchannel(cdev->dev.parent);
	295
	296	/* Setup nop channel program. */
	297	ccw = cdev->private->iccws;
	298	ccw->cmd_code = CCW_CMD_NOOP;
	299	ccw->cda = 0;
	300	ccw->count = 0;
	301	ccw->flags = CCW_FLAG_SLI;
	302
	303	/* Reset device status. */
	304	memset(&cdev->private->irb, 0, sizeof(struct irb));
	305
	306	/* Try multiple times. */
28bdc6f6	307	ret = -EACCES;
7e560814 CH	308	if (cdev->private->iretry > 0) {
7e560814 CH	309	cdev->private->iretry--;
d23861ff CH	310	/* Reset internal retry indication. */
d23861ff CH	311	cdev->private->flags.intretry = 0;
7e560814 CH	312	ret = cio_start (sch, cdev->private->iccws,
7e560814 CH	313	cdev->private->imask);
28bdc6f6 PO	314	/* We expect an interrupt in case of success or busy
	315	* indication. */
	316	if ((ret == 0) \|\| (ret == -EBUSY))
7e560814 CH	317	return ret;
7e560814 CH	318	}
28bdc6f6	319	/* nop command failed on this path. */
7e560814 CH	320	CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
7e560814 CH	321	"0.%x.%04x, lpm %02X, became 'not operational'\n",
78964268	322	cdev->private->dev_id.devno, sch->schid.ssid,
7e560814 CH	323	sch->schid.sch_no, cdev->private->imask);
	324	return ret;
	325	}
	326
	327
1da177e4 LT	328	/*
	329	* Called from interrupt context to check if a valid answer
	330	* to Set Path Group ID was received.
	331	*/
	332	static int
	333	__ccw_device_check_pgid(struct ccw_device *cdev)
	334	{
	335	struct subchannel *sch;
	336	struct irb *irb;
	337
	338	sch = to_subchannel(cdev->dev.parent);
	339	irb = &cdev->private->irb;
d23861ff CH	340	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC)) {
	341	/* Retry Set PGID if requested. */
	342	if (cdev->private->flags.intretry) {
	343	cdev->private->flags.intretry = 0;
	344	return -EAGAIN;
	345	}
1da177e4	346	return -ETIME;
d23861ff	347	}
1da177e4 LT	348	if (irb->esw.esw0.erw.cons) {
	349	if (irb->ecw[0] & SNS0_CMD_REJECT)
	350	return -EOPNOTSUPP;
	351	/* Hmm, whatever happened, try again. */
fb6958a5 CH	352	CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
fb6958a5 CH	353	"cnt %02d, "
1da177e4	354	"sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
78964268 CH	355	cdev->private->dev_id.ssid,
	356	cdev->private->dev_id.devno,
	357	irb->esw.esw0.erw.scnt,
1da177e4 LT	358	irb->ecw[0], irb->ecw[1],
	359	irb->ecw[2], irb->ecw[3],
	360	irb->ecw[4], irb->ecw[5],
	361	irb->ecw[6], irb->ecw[7]);
	362	return -EAGAIN;
	363	}
	364	if (irb->scsw.cc == 3) {
fb6958a5 CH	365	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
fb6958a5 CH	366	" lpm %02X, became 'not operational'\n",
78964268	367	cdev->private->dev_id.devno, sch->schid.ssid,
fb6958a5	368	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	369	return -EACCES;
	370	}
	371	return 0;
	372	}
	373
7e560814 CH	374	/*
	375	* Called from interrupt context to check the path status after a nop has
	376	* been send.
	377	*/
	378	static int __ccw_device_check_nop(struct ccw_device *cdev)
	379	{
	380	struct subchannel *sch;
	381	struct irb *irb;
	382
	383	sch = to_subchannel(cdev->dev.parent);
	384	irb = &cdev->private->irb;
d23861ff CH	385	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC)) {
	386	/* Retry NOP if requested. */
	387	if (cdev->private->flags.intretry) {
	388	cdev->private->flags.intretry = 0;
	389	return -EAGAIN;
	390	}
7e560814	391	return -ETIME;
d23861ff	392	}
7e560814 CH	393	if (irb->scsw.cc == 3) {
	394	CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
	395	" lpm %02X, became 'not operational'\n",
78964268	396	cdev->private->dev_id.devno, sch->schid.ssid,
7e560814 CH	397	sch->schid.sch_no, cdev->private->imask);
	398	return -EACCES;
	399	}
	400	return 0;
	401	}
	402
1da177e4 LT	403	static void
	404	__ccw_device_verify_start(struct ccw_device *cdev)
	405	{
	406	struct subchannel *sch;
28bdc6f6	407	__u8 func;
1da177e4 LT	408	int ret;
	409
	410	sch = to_subchannel(cdev->dev.parent);
28bdc6f6 PO	411	/* Repeat for all paths. */
	412	for (; cdev->private->imask; cdev->private->imask >>= 1,
	413	cdev->private->iretry = 5) {
	414	if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
	415	/* Path not available, try next. */
	416	continue;
7e560814	417	if (cdev->private->options.pgroup) {
28bdc6f6 PO	418	if (sch->opm & cdev->private->imask)
	419	func = SPID_FUNC_ESTABLISH;
	420	else
	421	func = SPID_FUNC_RESIGN;
7e560814 CH	422	ret = __ccw_device_do_pgid(cdev, func);
	423	} else
	424	ret = __ccw_device_do_nop(cdev);
28bdc6f6 PO	425	/* We expect an interrupt in case of success or busy
28bdc6f6 PO	426	* indication. */
1da177e4 LT	427	if (ret == 0 \|\| ret == -EBUSY)
1da177e4 LT	428	return;
28bdc6f6	429	/* Permanent path failure, try next. */
1da177e4	430	}
28bdc6f6 PO	431	/* Done with all paths. */
28bdc6f6 PO	432	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
1da177e4 LT	433	}
	434
	435	/*
	436	* Got interrupt for Set Path Group ID.
	437	*/
	438	void
	439	ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
	440	{
	441	struct subchannel *sch;
	442	struct irb *irb;
	443	int ret;
	444
	445	irb = (struct irb *) __LC_IRB;
7b7db1b5	446
1da177e4 LT	447	if (irb->scsw.stctl ==
1da177e4 LT	448	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	449	if (__ccw_device_should_retry(&irb->scsw))
1da177e4 LT	450	__ccw_device_verify_start(cdev);
	451	return;
	452	}
	453	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	454	return;
	455	sch = to_subchannel(cdev->dev.parent);
7e560814 CH	456	if (cdev->private->options.pgroup)
	457	ret = __ccw_device_check_pgid(cdev);
	458	else
	459	ret = __ccw_device_check_nop(cdev);
1da177e4	460	memset(&cdev->private->irb, 0, sizeof(struct irb));
28bdc6f6	461
1da177e4 LT	462	switch (ret) {
	463	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	464	case 0:
28bdc6f6 PO	465	/* Path verification ccw finished successfully, update lpm. */
	466	sch->vpm \|= sch->opm & cdev->private->imask;
	467	/* Go on with next path. */
	468	cdev->private->imask >>= 1;
1da177e4 LT	469	cdev->private->iretry = 5;
	470	__ccw_device_verify_start(cdev);
	471	break;
	472	case -EOPNOTSUPP:
	473	/*
	474	* One of those strange devices which claim to be able
	475	* to do multipathing but not for Set Path Group ID.
	476	*/
7e560814 CH	477	if (cdev->private->flags.pgid_single)
	478	cdev->private->options.pgroup = 0;
	479	else
	480	cdev->private->flags.pgid_single = 1;
28bdc6f6 PO	481	/* Retry */
	482	sch->vpm = 0;
	483	cdev->private->imask = 0x80;
	484	cdev->private->iretry = 5;
1da177e4 LT	485	/* fall through. */
	486	case -EAGAIN: /* Try again. */
	487	__ccw_device_verify_start(cdev);
	488	break;
	489	case -ETIME: /* Set path group id stopped by timeout. */
	490	ccw_device_verify_done(cdev, -ETIME);
	491	break;
	492	case -EACCES: /* channel is not operational. */
28bdc6f6	493	cdev->private->imask >>= 1;
1da177e4 LT	494	cdev->private->iretry = 5;
	495	__ccw_device_verify_start(cdev);
	496	break;
	497	}
	498	}
	499
	500	void
	501	ccw_device_verify_start(struct ccw_device *cdev)
	502	{
6810a2bc CH	503	struct subchannel *sch = to_subchannel(cdev->dev.parent);
6810a2bc CH	504
1da177e4	505	cdev->private->flags.pgid_single = 0;
28bdc6f6	506	cdev->private->imask = 0x80;
1da177e4	507	cdev->private->iretry = 5;
28bdc6f6 PO	508
	509	/* Start with empty vpm. */
	510	sch->vpm = 0;
	511
	512	/* Get current pam. */
a8237fc4	513	if (stsch(sch->schid, &sch->schib)) {
6810a2bc CH	514	ccw_device_verify_done(cdev, -ENODEV);
	515	return;
	516	}
f1ee3281 CH	517	/* After 60s path verification is considered to have failed. */
f1ee3281 CH	518	ccw_device_set_timeout(cdev, 60*HZ);
1da177e4 LT	519	__ccw_device_verify_start(cdev);
	520	}
	521
	522	static void
	523	__ccw_device_disband_start(struct ccw_device *cdev)
	524	{
	525	struct subchannel *sch;
	526	int ret;
	527
	528	sch = to_subchannel(cdev->dev.parent);
	529	while (cdev->private->imask != 0) {
	530	if (sch->lpm & cdev->private->imask) {
	531	ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
	532	if (ret == 0)
	533	return;
	534	}
	535	cdev->private->iretry = 5;
	536	cdev->private->imask >>= 1;
	537	}
6d751c43	538	ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
1da177e4 LT	539	}
	540
	541	/*
	542	* Got interrupt for Unset Path Group ID.
	543	*/
	544	void
	545	ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
	546	{
	547	struct subchannel *sch;
	548	struct irb *irb;
	549	int ret;
	550
	551	irb = (struct irb *) __LC_IRB;
7b7db1b5	552
1da177e4 LT	553	if (irb->scsw.stctl ==
1da177e4 LT	554	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	555	if (__ccw_device_should_retry(&irb->scsw))
1da177e4 LT	556	__ccw_device_disband_start(cdev);
	557	return;
	558	}
	559	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	560	return;
	561	sch = to_subchannel(cdev->dev.parent);
	562	ret = __ccw_device_check_pgid(cdev);
	563	memset(&cdev->private->irb, 0, sizeof(struct irb));
	564	switch (ret) {
	565	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	566	case 0: /* disband successful. */
1da177e4 LT	567	ccw_device_disband_done(cdev, ret);
	568	break;
	569	case -EOPNOTSUPP:
	570	/*
	571	* One of those strange devices which claim to be able
	572	* to do multipathing but not for Unset Path Group ID.
	573	*/
	574	cdev->private->flags.pgid_single = 1;
	575	/* fall through. */
	576	case -EAGAIN: /* Try again. */
	577	__ccw_device_disband_start(cdev);
	578	break;
	579	case -ETIME: /* Set path group id stopped by timeout. */
	580	ccw_device_disband_done(cdev, -ETIME);
	581	break;
	582	case -EACCES: /* channel is not operational. */
	583	cdev->private->imask >>= 1;
	584	cdev->private->iretry = 5;
	585	__ccw_device_disband_start(cdev);
	586	break;
	587	}
	588	}
	589
	590	void
	591	ccw_device_disband_start(struct ccw_device *cdev)
	592	{
f1ee3281 CH	593	/* After 60s disbanding is considered to have failed. */
	594	ccw_device_set_timeout(cdev, 60*HZ);
	595
1da177e4 LT	596	cdev->private->flags.pgid_single = 0;
	597	cdev->private->iretry = 5;
	598	cdev->private->imask = 0x80;
	599	__ccw_device_disband_start(cdev);
	600	}