[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"
#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(union scsw *scsw)
{
	/* CC is only valid if start function bit is set. */
	if ((scsw->cmd.fctl & SCSW_FCTL_START_FUNC) && scsw->cmd.cc == 1)
		return 1;
	/* No more activity. For sense and set PGID we stubbornly try again. */
	if (!scsw->cmd.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(3, "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.cmd.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.cmd.cc == 3) {
		u8 lpm;

		lpm = to_io_private(sch)->orb.cmd.lpm;
		CIO_MSG_EVENT(3, "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.cmd.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_SINGLE_PATH;
	else
		cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_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(3, "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(3, "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.cmd.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.cmd.cc == 3) {
		CIO_MSG_EVENT(3, "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.cmd.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.cmd.cc == 3) {
		CIO_MSG_EVENT(3, "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.cmd.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 (cio_update_schib(sch)) {
		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.cmd.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	*/
23d805b6	31	static int __ccw_device_should_retry(union scsw *scsw)
7b7db1b5 SB	32	{
7b7db1b5 SB	33	/* CC is only valid if start function bit is set. */
23d805b6	34	if ((scsw->cmd.fctl & SCSW_FCTL_START_FUNC) && scsw->cmd.cc == 1)
7b7db1b5 SB	35	return 1;
7b7db1b5 SB	36	/* No more activity. For sense and set PGID we stubbornly try again. */
23d805b6	37	if (!scsw->cmd.actl)
7b7db1b5 SB	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;
139b83dd	82	CIO_MSG_EVENT(3, "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;
23d805b6	128	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC)) {
d23861ff CH	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	}
23d805b6	158	if (irb->scsw.cmd.cc == 3) {
cd6b4f27 CH	159	u8 lpm;
cd6b4f27 CH	160
83262d63	161	lpm = to_io_private(sch)->orb.cmd.lpm;
139b83dd	162	CIO_MSG_EVENT(3, "SNID - Device %04x on Subchannel 0.%x.%04x,"
fb6958a5	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
23d805b6	191	if (irb->scsw.cmd.stctl ==
1da177e4	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	245	ccw = cdev->private->iccws;
32aff573	246	if (cdev->private->flags.pgid_single)
7e560814	247	cdev->private->pgid[0].inf.fc \|= SPID_FUNC_SINGLE_PATH;
32aff573 ME	248	else
32aff573 ME	249	cdev->private->pgid[0].inf.fc \|= SPID_FUNC_MULTI_PATH;
1da177e4	250	ccw->cmd_code = CCW_CMD_SET_PGID;
7e560814	251	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
1da177e4 LT	252	ccw->count = sizeof (struct pgid);
	253	ccw->flags = CCW_FLAG_SLI;
	254
	255	/* Reset device status. */
	256	memset(&cdev->private->irb, 0, sizeof(struct irb));
	257
	258	/* Try multiple times. */
28bdc6f6	259	ret = -EACCES;
1da177e4 LT	260	if (cdev->private->iretry > 0) {
1da177e4 LT	261	cdev->private->iretry--;
d23861ff CH	262	/* Reset internal retry indication. */
d23861ff CH	263	cdev->private->flags.intretry = 0;
1da177e4 LT	264	ret = cio_start (sch, cdev->private->iccws,
1da177e4 LT	265	cdev->private->imask);
28bdc6f6 PO	266	/* We expect an interrupt in case of success or busy
	267	* indication. */
	268	if ((ret == 0) \|\| (ret == -EBUSY))
1da177e4 LT	269	return ret;
1da177e4 LT	270	}
28bdc6f6	271	/* PGID command failed on this path. */
139b83dd	272	CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel "
fb6958a5	273	"0.%x.%04x, lpm %02X, became 'not operational'\n",
78964268	274	cdev->private->dev_id.devno, sch->schid.ssid,
fb6958a5	275	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	276	return ret;
	277	}
	278
7e560814 CH	279	/*
	280	* Helper function to send a nop ccw down a path.
	281	*/
	282	static int __ccw_device_do_nop(struct ccw_device *cdev)
	283	{
	284	struct subchannel *sch;
	285	struct ccw1 *ccw;
	286	int ret;
	287
	288	sch = to_subchannel(cdev->dev.parent);
	289
	290	/* Setup nop channel program. */
	291	ccw = cdev->private->iccws;
	292	ccw->cmd_code = CCW_CMD_NOOP;
	293	ccw->cda = 0;
	294	ccw->count = 0;
	295	ccw->flags = CCW_FLAG_SLI;
	296
	297	/* Reset device status. */
	298	memset(&cdev->private->irb, 0, sizeof(struct irb));
	299
	300	/* Try multiple times. */
28bdc6f6	301	ret = -EACCES;
7e560814 CH	302	if (cdev->private->iretry > 0) {
7e560814 CH	303	cdev->private->iretry--;
d23861ff CH	304	/* Reset internal retry indication. */
d23861ff CH	305	cdev->private->flags.intretry = 0;
7e560814 CH	306	ret = cio_start (sch, cdev->private->iccws,
7e560814 CH	307	cdev->private->imask);
28bdc6f6 PO	308	/* We expect an interrupt in case of success or busy
	309	* indication. */
	310	if ((ret == 0) \|\| (ret == -EBUSY))
7e560814 CH	311	return ret;
7e560814 CH	312	}
28bdc6f6	313	/* nop command failed on this path. */
139b83dd	314	CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel "
7e560814	315	"0.%x.%04x, lpm %02X, became 'not operational'\n",
78964268	316	cdev->private->dev_id.devno, sch->schid.ssid,
7e560814 CH	317	sch->schid.sch_no, cdev->private->imask);
	318	return ret;
	319	}
	320
	321
1da177e4 LT	322	/*
	323	* Called from interrupt context to check if a valid answer
	324	* to Set Path Group ID was received.
	325	*/
	326	static int
	327	__ccw_device_check_pgid(struct ccw_device *cdev)
	328	{
	329	struct subchannel *sch;
	330	struct irb *irb;
	331
	332	sch = to_subchannel(cdev->dev.parent);
	333	irb = &cdev->private->irb;
23d805b6	334	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC)) {
d23861ff CH	335	/* Retry Set PGID if requested. */
	336	if (cdev->private->flags.intretry) {
	337	cdev->private->flags.intretry = 0;
	338	return -EAGAIN;
	339	}
1da177e4	340	return -ETIME;
d23861ff	341	}
1da177e4 LT	342	if (irb->esw.esw0.erw.cons) {
	343	if (irb->ecw[0] & SNS0_CMD_REJECT)
	344	return -EOPNOTSUPP;
	345	/* Hmm, whatever happened, try again. */
fb6958a5 CH	346	CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
fb6958a5 CH	347	"cnt %02d, "
1da177e4	348	"sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
78964268 CH	349	cdev->private->dev_id.ssid,
	350	cdev->private->dev_id.devno,
	351	irb->esw.esw0.erw.scnt,
1da177e4 LT	352	irb->ecw[0], irb->ecw[1],
	353	irb->ecw[2], irb->ecw[3],
	354	irb->ecw[4], irb->ecw[5],
	355	irb->ecw[6], irb->ecw[7]);
	356	return -EAGAIN;
	357	}
23d805b6	358	if (irb->scsw.cmd.cc == 3) {
139b83dd	359	CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel 0.%x.%04x,"
fb6958a5	360	" lpm %02X, became 'not operational'\n",
78964268	361	cdev->private->dev_id.devno, sch->schid.ssid,
fb6958a5	362	sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	363	return -EACCES;
	364	}
	365	return 0;
	366	}
	367
7e560814 CH	368	/*
	369	* Called from interrupt context to check the path status after a nop has
	370	* been send.
	371	*/
	372	static int __ccw_device_check_nop(struct ccw_device *cdev)
	373	{
	374	struct subchannel *sch;
	375	struct irb *irb;
	376
	377	sch = to_subchannel(cdev->dev.parent);
	378	irb = &cdev->private->irb;
23d805b6	379	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC)) {
d23861ff CH	380	/* Retry NOP if requested. */
	381	if (cdev->private->flags.intretry) {
	382	cdev->private->flags.intretry = 0;
	383	return -EAGAIN;
	384	}
7e560814	385	return -ETIME;
d23861ff	386	}
23d805b6	387	if (irb->scsw.cmd.cc == 3) {
139b83dd	388	CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel 0.%x.%04x,"
7e560814	389	" lpm %02X, became 'not operational'\n",
78964268	390	cdev->private->dev_id.devno, sch->schid.ssid,
7e560814 CH	391	sch->schid.sch_no, cdev->private->imask);
	392	return -EACCES;
	393	}
	394	return 0;
	395	}
	396
1da177e4 LT	397	static void
	398	__ccw_device_verify_start(struct ccw_device *cdev)
	399	{
	400	struct subchannel *sch;
28bdc6f6	401	__u8 func;
1da177e4 LT	402	int ret;
	403
	404	sch = to_subchannel(cdev->dev.parent);
28bdc6f6 PO	405	/* Repeat for all paths. */
	406	for (; cdev->private->imask; cdev->private->imask >>= 1,
	407	cdev->private->iretry = 5) {
	408	if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
	409	/* Path not available, try next. */
	410	continue;
7e560814	411	if (cdev->private->options.pgroup) {
28bdc6f6 PO	412	if (sch->opm & cdev->private->imask)
	413	func = SPID_FUNC_ESTABLISH;
	414	else
	415	func = SPID_FUNC_RESIGN;
7e560814 CH	416	ret = __ccw_device_do_pgid(cdev, func);
	417	} else
	418	ret = __ccw_device_do_nop(cdev);
28bdc6f6 PO	419	/* We expect an interrupt in case of success or busy
28bdc6f6 PO	420	* indication. */
1da177e4 LT	421	if (ret == 0 \|\| ret == -EBUSY)
1da177e4 LT	422	return;
28bdc6f6	423	/* Permanent path failure, try next. */
1da177e4	424	}
28bdc6f6 PO	425	/* Done with all paths. */
28bdc6f6 PO	426	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
1da177e4 LT	427	}
	428
	429	/*
	430	* Got interrupt for Set Path Group ID.
	431	*/
	432	void
	433	ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
	434	{
	435	struct subchannel *sch;
	436	struct irb *irb;
	437	int ret;
	438
	439	irb = (struct irb *) __LC_IRB;
7b7db1b5	440
23d805b6	441	if (irb->scsw.cmd.stctl ==
1da177e4	442	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	443	if (__ccw_device_should_retry(&irb->scsw))
1da177e4 LT	444	__ccw_device_verify_start(cdev);
	445	return;
	446	}
	447	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	448	return;
	449	sch = to_subchannel(cdev->dev.parent);
7e560814 CH	450	if (cdev->private->options.pgroup)
	451	ret = __ccw_device_check_pgid(cdev);
	452	else
	453	ret = __ccw_device_check_nop(cdev);
1da177e4	454	memset(&cdev->private->irb, 0, sizeof(struct irb));
28bdc6f6	455
1da177e4 LT	456	switch (ret) {
	457	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	458	case 0:
28bdc6f6 PO	459	/* Path verification ccw finished successfully, update lpm. */
	460	sch->vpm \|= sch->opm & cdev->private->imask;
	461	/* Go on with next path. */
	462	cdev->private->imask >>= 1;
1da177e4 LT	463	cdev->private->iretry = 5;
	464	__ccw_device_verify_start(cdev);
	465	break;
	466	case -EOPNOTSUPP:
	467	/*
	468	* One of those strange devices which claim to be able
	469	* to do multipathing but not for Set Path Group ID.
	470	*/
7e560814 CH	471	if (cdev->private->flags.pgid_single)
	472	cdev->private->options.pgroup = 0;
	473	else
	474	cdev->private->flags.pgid_single = 1;
28bdc6f6 PO	475	/* Retry */
	476	sch->vpm = 0;
	477	cdev->private->imask = 0x80;
	478	cdev->private->iretry = 5;
1da177e4 LT	479	/* fall through. */
	480	case -EAGAIN: /* Try again. */
	481	__ccw_device_verify_start(cdev);
	482	break;
	483	case -ETIME: /* Set path group id stopped by timeout. */
	484	ccw_device_verify_done(cdev, -ETIME);
	485	break;
	486	case -EACCES: /* channel is not operational. */
28bdc6f6	487	cdev->private->imask >>= 1;
1da177e4 LT	488	cdev->private->iretry = 5;
	489	__ccw_device_verify_start(cdev);
	490	break;
	491	}
	492	}
	493
	494	void
	495	ccw_device_verify_start(struct ccw_device *cdev)
	496	{
6810a2bc CH	497	struct subchannel *sch = to_subchannel(cdev->dev.parent);
6810a2bc CH	498
1da177e4	499	cdev->private->flags.pgid_single = 0;
28bdc6f6	500	cdev->private->imask = 0x80;
1da177e4	501	cdev->private->iretry = 5;
28bdc6f6 PO	502
	503	/* Start with empty vpm. */
	504	sch->vpm = 0;
	505
	506	/* Get current pam. */
cdb912a4	507	if (cio_update_schib(sch)) {
6810a2bc CH	508	ccw_device_verify_done(cdev, -ENODEV);
	509	return;
	510	}
f1ee3281 CH	511	/* After 60s path verification is considered to have failed. */
f1ee3281 CH	512	ccw_device_set_timeout(cdev, 60*HZ);
1da177e4 LT	513	__ccw_device_verify_start(cdev);
	514	}
	515
	516	static void
	517	__ccw_device_disband_start(struct ccw_device *cdev)
	518	{
	519	struct subchannel *sch;
	520	int ret;
	521
	522	sch = to_subchannel(cdev->dev.parent);
	523	while (cdev->private->imask != 0) {
	524	if (sch->lpm & cdev->private->imask) {
	525	ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
	526	if (ret == 0)
	527	return;
	528	}
	529	cdev->private->iretry = 5;
	530	cdev->private->imask >>= 1;
	531	}
6d751c43	532	ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
1da177e4 LT	533	}
	534
	535	/*
	536	* Got interrupt for Unset Path Group ID.
	537	*/
	538	void
	539	ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
	540	{
	541	struct subchannel *sch;
	542	struct irb *irb;
	543	int ret;
	544
	545	irb = (struct irb *) __LC_IRB;
7b7db1b5	546
23d805b6	547	if (irb->scsw.cmd.stctl ==
1da177e4	548	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
7b7db1b5	549	if (__ccw_device_should_retry(&irb->scsw))
1da177e4 LT	550	__ccw_device_disband_start(cdev);
	551	return;
	552	}
	553	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	554	return;
	555	sch = to_subchannel(cdev->dev.parent);
	556	ret = __ccw_device_check_pgid(cdev);
	557	memset(&cdev->private->irb, 0, sizeof(struct irb));
	558	switch (ret) {
	559	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	560	case 0: /* disband successful. */
1da177e4 LT	561	ccw_device_disband_done(cdev, ret);
	562	break;
	563	case -EOPNOTSUPP:
	564	/*
	565	* One of those strange devices which claim to be able
	566	* to do multipathing but not for Unset Path Group ID.
	567	*/
	568	cdev->private->flags.pgid_single = 1;
	569	/* fall through. */
	570	case -EAGAIN: /* Try again. */
	571	__ccw_device_disband_start(cdev);
	572	break;
	573	case -ETIME: /* Set path group id stopped by timeout. */
	574	ccw_device_disband_done(cdev, -ETIME);
	575	break;
	576	case -EACCES: /* channel is not operational. */
	577	cdev->private->imask >>= 1;
	578	cdev->private->iretry = 5;
	579	__ccw_device_disband_start(cdev);
	580	break;
	581	}
	582	}
	583
	584	void
	585	ccw_device_disband_start(struct ccw_device *cdev)
	586	{
f1ee3281 CH	587	/* After 60s disbanding is considered to have failed. */
	588	ccw_device_set_timeout(cdev, 60*HZ);
	589
1da177e4 LT	590	cdev->private->flags.pgid_single = 0;
	591	cdev->private->iretry = 5;
	592	cdev->private->imask = 0x80;
	593	__ccw_device_disband_start(cdev);
	594	}