[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"

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