[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(cohuck@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 * Path Group ID functions.
 */

#include <linux/config.h>
#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"

/*
 * 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;

	sch = to_subchannel(cdev->dev.parent);
	/* Setup sense path group id channel program. */
	ccw = cdev->private->iccws;
	ccw->cmd_code = CCW_CMD_SENSE_PGID;
	ccw->cda = (__u32) __pa (&cdev->private->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. */
		if (cdev->private->iretry > 0) {
			cdev->private->iretry--;
			ret = cio_start (sch, cdev->private->iccws, 
					 cdev->private->imask);
			/* ret is 0, -EBUSY, -EACCES or -ENODEV */
			if (ret != -EACCES)
				return ret;
			CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
				      "%04x, lpm %02X, became 'not "
				      "operational'\n",
				      cdev->private->devno, sch->schid.sch_no,
				      cdev->private->imask);

		}
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
	}
	return ret;
}

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

	cdev->private->state = DEV_STATE_SENSE_PGID;
	cdev->private->imask = 0x80;
	cdev->private->iretry = 5;
	memset (&cdev->private->pgid, 0, sizeof (struct 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;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
		return -ETIME;
	if (irb->esw.esw0.erw.cons &&
	    (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
		/*
		 * If the device doesn't support the Sense Path Group ID
		 *  command further retries wouldn't help ...
		 */
		return -EOPNOTSUPP;
	}
	if (irb->esw.esw0.erw.cons) {
		CIO_MSG_EVENT(2, "SNID - device %04x, unit check, "
			      "lpum %02X, cnt %02d, sns : "
			      "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
			      cdev->private->devno,
			      irb->esw.esw0.sublog.lpum,
			      irb->esw.esw0.erw.scnt,
			      irb->ecw[0], irb->ecw[1],
			      irb->ecw[2], irb->ecw[3],
			      irb->ecw[4], irb->ecw[5],
			      irb->ecw[6], irb->ecw[7]);
		return -EAGAIN;
	}
	if (irb->scsw.cc == 3) {
		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
			      "%04x, lpm %02X, became 'not operational'\n",
			      cdev->private->devno, sch->schid.sch_no,
			      sch->orb.lpm);
		return -EACCES;
	}
	if (cdev->private->pgid.inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel %04x "
			      "is reserved by someone else\n",
			      cdev->private->devno, 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;
	/* Retry sense pgid for cc=1. */
	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (irb->scsw.cc == 1) {
			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 0:			/* Sense Path Group ID successful. */
		if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
			memcpy(&cdev->private->pgid, &css[0]->global_pgid,
			       sizeof(struct pgid));
		ccw_device_sense_pgid_done(cdev, 0);
		break;
	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;
		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, -ENODEV);
		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.inf.fc = func;
	ccw = cdev->private->iccws;
	if (!cdev->private->flags.pgid_single) {
		cdev->private->pgid.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.inf.fc |= SPID_FUNC_SINGLE_PATH;

	ccw->cmd_code = CCW_CMD_SET_PGID;
	ccw->cda = (__u32) __pa (&cdev->private->pgid);
	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 = -ENODEV;
	if (cdev->private->iretry > 0) {
		cdev->private->iretry--;
		ret = cio_start (sch, cdev->private->iccws,
				 cdev->private->imask);
		/* ret is 0, -EBUSY, -EACCES or -ENODEV */
		if ((ret != -EACCES) && (ret != -ENODEV))
			return ret;
	}
	/* PGID command failed on this path. Switch it off. */
	sch->lpm &= ~cdev->private->imask;
	sch->vpm &= ~cdev->private->imask;
	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
		      "%04x, lpm %02X, became 'not operational'\n",
		      cdev->private->devno, sch->schid.sch_no, cdev->private->imask);
	return ret;
}

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

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

	sch = to_subchannel(cdev->dev.parent);
	while (sch->vpm != sch->lpm) {
		/* Find first unequal bit in vpm vs. lpm */
		for (imask = 0x80; imask != 0; imask >>= 1)
			if ((sch->vpm & imask) != (sch->lpm & imask))
				break;
		cdev->private->imask = imask;
		func = (sch->vpm & imask) ?
			SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
		ret = __ccw_device_do_pgid(cdev, func);
		if (ret == 0 || ret == -EBUSY)
			return;
		cdev->private->iretry = 5;
	}
	ccw_device_verify_done(cdev, (sch->lpm != 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;
	/* Retry set pgid for cc=1. */
	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (irb->scsw.cc == 1)
			__ccw_device_verify_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:
		/* Establish or Resign Path Group done. Update vpm. */
		if ((sch->lpm & cdev->private->imask) != 0)
			sch->vpm |= cdev->private->imask;
		else
			sch->vpm &= ~cdev->private->imask;
		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) {
			ccw_device_verify_done(cdev, -EOPNOTSUPP);
			break;
		}
		cdev->private->flags.pgid_single = 1;
		/* 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. */
		sch->lpm &= ~cdev->private->imask;
		sch->vpm &= ~cdev->private->imask;
		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->iretry = 5;
	/*
	 * Update sch->lpm with current values to catch paths becoming
	 * available again.
	 */
	if (stsch(sch->schid, &sch->schib)) {
		ccw_device_verify_done(cdev, -ENODEV);
		return;
	}
	sch->lpm = sch->schib.pmcw.pim &
		sch->schib.pmcw.pam &
		sch->schib.pmcw.pom &
		sch->opm;
	__ccw_device_verify_start(cdev);
}

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_verify_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;
	/* Retry set pgid for cc=1. */
	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (irb->scsw.cc == 1)
			__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. */
		sch->vpm = 0;
		ccw_device_disband_done(cdev, ret);
		break;
	case -EOPNOTSUPP:
		/*
		 * One of those strange devices which claim to be able
		 * to do multipathing but not for Unset Path Group ID.
		 */
		cdev->private->flags.pgid_single = 1;
		/* fall through. */
	case -EAGAIN:		/* Try again. */
		__ccw_device_disband_start(cdev);
		break;
	case -ETIME:		/* Set path group id stopped by timeout. */
		ccw_device_disband_done(cdev, -ETIME);
		break;
	case -EACCES:		/* channel is not operational. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		__ccw_device_disband_start(cdev);
		break;
	}
}

void
ccw_device_disband_start(struct ccw_device *cdev)
{
	cdev->private->flags.pgid_single = 0;
	cdev->private->iretry = 5;
	cdev->private->imask = 0x80;
	__ccw_device_disband_start(cdev);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/s390/cio/device_pgid.c
	3	*
	4	* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
	5	* IBM Corporation
	6	* Author(s): Cornelia Huck(cohuck@de.ibm.com)
	7	* Martin Schwidefsky (schwidefsky@de.ibm.com)
	8	*
	9	* Path Group ID functions.
	10	*/
	11
	12	#include <linux/config.h>
	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15
	16	#include <asm/ccwdev.h>
	17	#include <asm/cio.h>
	18	#include <asm/delay.h>
	19	#include <asm/lowcore.h>
	20
	21	#include "cio.h"
	22	#include "cio_debug.h"
	23	#include "css.h"
	24	#include "device.h"
6810a2bc	25	#include "ioasm.h"
1da177e4 LT	26
	27	/*
	28	* Start Sense Path Group ID helper function. Used in ccw_device_recog
	29	* and ccw_device_sense_pgid.
	30	*/
	31	static int
	32	__ccw_device_sense_pgid_start(struct ccw_device *cdev)
	33	{
	34	struct subchannel *sch;
	35	struct ccw1 *ccw;
	36	int ret;
	37
	38	sch = to_subchannel(cdev->dev.parent);
	39	/* Setup sense path group id channel program. */
	40	ccw = cdev->private->iccws;
	41	ccw->cmd_code = CCW_CMD_SENSE_PGID;
	42	ccw->cda = (__u32) __pa (&cdev->private->pgid);
	43	ccw->count = sizeof (struct pgid);
	44	ccw->flags = CCW_FLAG_SLI;
	45
	46	/* Reset device status. */
	47	memset(&cdev->private->irb, 0, sizeof(struct irb));
	48	/* Try on every path. */
	49	ret = -ENODEV;
	50	while (cdev->private->imask != 0) {
	51	/* Try every path multiple times. */
	52	if (cdev->private->iretry > 0) {
	53	cdev->private->iretry--;
	54	ret = cio_start (sch, cdev->private->iccws,
	55	cdev->private->imask);
	56	/* ret is 0, -EBUSY, -EACCES or -ENODEV */
	57	if (ret != -EACCES)
	58	return ret;
	59	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
	60	"%04x, lpm %02X, became 'not "
	61	"operational'\n",
a8237fc4	62	cdev->private->devno, sch->schid.sch_no,
1da177e4 LT	63	cdev->private->imask);
	64
	65	}
	66	cdev->private->imask >>= 1;
	67	cdev->private->iretry = 5;
	68	}
	69	return ret;
	70	}
	71
	72	void
	73	ccw_device_sense_pgid_start(struct ccw_device *cdev)
	74	{
	75	int ret;
	76
	77	cdev->private->state = DEV_STATE_SENSE_PGID;
	78	cdev->private->imask = 0x80;
	79	cdev->private->iretry = 5;
	80	memset (&cdev->private->pgid, 0, sizeof (struct pgid));
	81	ret = __ccw_device_sense_pgid_start(cdev);
	82	if (ret && ret != -EBUSY)
	83	ccw_device_sense_pgid_done(cdev, ret);
	84	}
	85
	86	/*
	87	* Called from interrupt context to check if a valid answer
	88	* to Sense Path Group ID was received.
	89	*/
	90	static int
	91	__ccw_device_check_sense_pgid(struct ccw_device *cdev)
	92	{
	93	struct subchannel *sch;
	94	struct irb *irb;
	95
	96	sch = to_subchannel(cdev->dev.parent);
	97	irb = &cdev->private->irb;
	98	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC))
	99	return -ETIME;
	100	if (irb->esw.esw0.erw.cons &&
	101	(irb->ecw[0]&(SNS0_CMD_REJECT\|SNS0_INTERVENTION_REQ))) {
	102	/*
	103	* If the device doesn't support the Sense Path Group ID
	104	* command further retries wouldn't help ...
	105	*/
	106	return -EOPNOTSUPP;
	107	}
	108	if (irb->esw.esw0.erw.cons) {
	109	CIO_MSG_EVENT(2, "SNID - device %04x, unit check, "
	110	"lpum %02X, cnt %02d, sns : "
	111	"%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
	112	cdev->private->devno,
	113	irb->esw.esw0.sublog.lpum,
	114	irb->esw.esw0.erw.scnt,
	115	irb->ecw[0], irb->ecw[1],
	116	irb->ecw[2], irb->ecw[3],
	117	irb->ecw[4], irb->ecw[5],
	118	irb->ecw[6], irb->ecw[7]);
	119	return -EAGAIN;
	120	}
	121	if (irb->scsw.cc == 3) {
	122	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
	123	"%04x, lpm %02X, became 'not operational'\n",
a8237fc4 CH	124	cdev->private->devno, sch->schid.sch_no,
a8237fc4 CH	125	sch->orb.lpm);
1da177e4 LT	126	return -EACCES;
	127	}
	128	if (cdev->private->pgid.inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
	129	CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel %04x "
	130	"is reserved by someone else\n",
a8237fc4	131	cdev->private->devno, sch->schid.sch_no);
1da177e4 LT	132	return -EUSERS;
	133	}
	134	return 0;
	135	}
	136
	137	/*
	138	* Got interrupt for Sense Path Group ID.
	139	*/
	140	void
	141	ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
	142	{
	143	struct subchannel *sch;
	144	struct irb *irb;
	145	int ret;
	146
	147	irb = (struct irb *) __LC_IRB;
	148	/* Retry sense pgid for cc=1. */
	149	if (irb->scsw.stctl ==
	150	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
	151	if (irb->scsw.cc == 1) {
	152	ret = __ccw_device_sense_pgid_start(cdev);
	153	if (ret && ret != -EBUSY)
	154	ccw_device_sense_pgid_done(cdev, ret);
	155	}
	156	return;
	157	}
	158	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	159	return;
	160	sch = to_subchannel(cdev->dev.parent);
	161	ret = __ccw_device_check_sense_pgid(cdev);
	162	memset(&cdev->private->irb, 0, sizeof(struct irb));
	163	switch (ret) {
	164	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
	165	case 0: /* Sense Path Group ID successful. */
	166	if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
a28c6944	167	memcpy(&cdev->private->pgid, &css[0]->global_pgid,
1da177e4 LT	168	sizeof(struct pgid));
	169	ccw_device_sense_pgid_done(cdev, 0);
	170	break;
	171	case -EOPNOTSUPP: /* Sense Path Group ID not supported */
	172	ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
	173	break;
	174	case -ETIME: /* Sense path group id stopped by timeout. */
	175	ccw_device_sense_pgid_done(cdev, -ETIME);
	176	break;
	177	case -EACCES: /* channel is not operational. */
	178	sch->lpm &= ~cdev->private->imask;
	179	cdev->private->imask >>= 1;
	180	cdev->private->iretry = 5;
	181	/* Fall through. */
	182	case -EAGAIN: /* Try again. */
	183	ret = __ccw_device_sense_pgid_start(cdev);
	184	if (ret != 0 && ret != -EBUSY)
	185	ccw_device_sense_pgid_done(cdev, -ENODEV);
	186	break;
	187	case -EUSERS: /* device is reserved for someone else. */
	188	ccw_device_sense_pgid_done(cdev, -EUSERS);
	189	break;
	190	}
	191	}
	192
	193	/*
	194	* Path Group ID helper function.
	195	*/
	196	static int
	197	__ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
	198	{
	199	struct subchannel *sch;
	200	struct ccw1 *ccw;
	201	int ret;
	202
	203	sch = to_subchannel(cdev->dev.parent);
	204
	205	/* Setup sense path group id channel program. */
	206	cdev->private->pgid.inf.fc = func;
	207	ccw = cdev->private->iccws;
	208	if (!cdev->private->flags.pgid_single) {
	209	cdev->private->pgid.inf.fc \|= SPID_FUNC_MULTI_PATH;
	210	ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
	211	ccw->cda = 0;
	212	ccw->count = 0;
	213	ccw->flags = CCW_FLAG_SLI \| CCW_FLAG_CC;
	214	ccw++;
	215	} else
	216	cdev->private->pgid.inf.fc \|= SPID_FUNC_SINGLE_PATH;
	217
	218	ccw->cmd_code = CCW_CMD_SET_PGID;
	219	ccw->cda = (__u32) __pa (&cdev->private->pgid);
	220	ccw->count = sizeof (struct pgid);
	221	ccw->flags = CCW_FLAG_SLI;
	222
	223	/* Reset device status. */
	224	memset(&cdev->private->irb, 0, sizeof(struct irb));
	225
	226	/* Try multiple times. */
	227	ret = -ENODEV;
	228	if (cdev->private->iretry > 0) {
	229	cdev->private->iretry--;
	230	ret = cio_start (sch, cdev->private->iccws,
	231	cdev->private->imask);
232	/* ret is 0, -EBUSY, -EACCES or -ENODEV */
233	if ((ret != -EACCES) && (ret != -ENODEV))
234	return ret;
235	}
236	/* PGID command failed on this path. Switch it off. */
237	sch->lpm &= ~cdev->private->imask;
238	sch->vpm &= ~cdev->private->imask;
239	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
240	"%04x, lpm %02X, became 'not operational'\n",
a8237fc4	241	cdev->private->devno, sch->schid.sch_no, cdev->private->imask);
1da177e4 LT	242	return ret;
	243	}
	244
	245	/*
	246	* Called from interrupt context to check if a valid answer
	247	* to Set Path Group ID was received.
	248	*/
	249	static int
	250	__ccw_device_check_pgid(struct ccw_device *cdev)
	251	{
	252	struct subchannel *sch;
	253	struct irb *irb;
	254
	255	sch = to_subchannel(cdev->dev.parent);
	256	irb = &cdev->private->irb;
	257	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC))
	258	return -ETIME;
	259	if (irb->esw.esw0.erw.cons) {
	260	if (irb->ecw[0] & SNS0_CMD_REJECT)
	261	return -EOPNOTSUPP;
	262	/* Hmm, whatever happened, try again. */
	263	CIO_MSG_EVENT(2, "SPID - device %04x, unit check, cnt %02d, "
	264	"sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
	265	cdev->private->devno, irb->esw.esw0.erw.scnt,
	266	irb->ecw[0], irb->ecw[1],
	267	irb->ecw[2], irb->ecw[3],
	268	irb->ecw[4], irb->ecw[5],
	269	irb->ecw[6], irb->ecw[7]);
	270	return -EAGAIN;
	271	}
	272	if (irb->scsw.cc == 3) {
	273	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
	274	"%04x, lpm %02X, became 'not operational'\n",
a8237fc4	275	cdev->private->devno, sch->schid.sch_no,
1da177e4 LT	276	cdev->private->imask);
	277	return -EACCES;
	278	}
	279	return 0;
	280	}
	281
	282	static void
	283	__ccw_device_verify_start(struct ccw_device *cdev)
	284	{
	285	struct subchannel *sch;
	286	__u8 imask, func;
	287	int ret;
	288
	289	sch = to_subchannel(cdev->dev.parent);
	290	while (sch->vpm != sch->lpm) {
	291	/* Find first unequal bit in vpm vs. lpm */
	292	for (imask = 0x80; imask != 0; imask >>= 1)
	293	if ((sch->vpm & imask) != (sch->lpm & imask))
	294	break;
	295	cdev->private->imask = imask;
	296	func = (sch->vpm & imask) ?
	297	SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
	298	ret = __ccw_device_do_pgid(cdev, func);
	299	if (ret == 0 \|\| ret == -EBUSY)
	300	return;
	301	cdev->private->iretry = 5;
	302	}
	303	ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
	304	}
	305
	306	/*
	307	* Got interrupt for Set Path Group ID.
	308	*/
	309	void
	310	ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
	311	{
	312	struct subchannel *sch;
	313	struct irb *irb;
	314	int ret;
	315
	316	irb = (struct irb *) __LC_IRB;
	317	/* Retry set pgid for cc=1. */
	318	if (irb->scsw.stctl ==
	319	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
	320	if (irb->scsw.cc == 1)
	321	__ccw_device_verify_start(cdev);
	322	return;
	323	}
	324	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	325	return;
	326	sch = to_subchannel(cdev->dev.parent);
	327	ret = __ccw_device_check_pgid(cdev);
	328	memset(&cdev->private->irb, 0, sizeof(struct irb));
	329	switch (ret) {
	330	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	331	case 0:
	332	/* Establish or Resign Path Group done. Update vpm. */
	333	if ((sch->lpm & cdev->private->imask) != 0)
	334	sch->vpm \|= cdev->private->imask;
	335	else
	336	sch->vpm &= ~cdev->private->imask;
	337	cdev->private->iretry = 5;
	338	__ccw_device_verify_start(cdev);
	339	break;
340	case -EOPNOTSUPP:
341	/*
342	* One of those strange devices which claim to be able
343	* to do multipathing but not for Set Path Group ID.
344	*/
345	if (cdev->private->flags.pgid_single) {
346	ccw_device_verify_done(cdev, -EOPNOTSUPP);
347	break;
348	}
349	cdev->private->flags.pgid_single = 1;
350	/* fall through. */
351	case -EAGAIN: /* Try again. */
352	__ccw_device_verify_start(cdev);
353	break;
354	case -ETIME: /* Set path group id stopped by timeout. */
355	ccw_device_verify_done(cdev, -ETIME);
356	break;
357	case -EACCES: /* channel is not operational. */
358	sch->lpm &= ~cdev->private->imask;
359	sch->vpm &= ~cdev->private->imask;
360	cdev->private->iretry = 5;
361	__ccw_device_verify_start(cdev);
362	break;
363	}
364	}
365
366	void
367	ccw_device_verify_start(struct ccw_device *cdev)
368	{
6810a2bc CH	369	struct subchannel *sch = to_subchannel(cdev->dev.parent);
6810a2bc CH	370
1da177e4 LT	371	cdev->private->flags.pgid_single = 0;
1da177e4 LT	372	cdev->private->iretry = 5;
6810a2bc CH	373	/*
	374	* Update sch->lpm with current values to catch paths becoming
	375	* available again.
	376	*/
a8237fc4	377	if (stsch(sch->schid, &sch->schib)) {
6810a2bc CH	378	ccw_device_verify_done(cdev, -ENODEV);
	379	return;
	380	}
	381	sch->lpm = sch->schib.pmcw.pim &
	382	sch->schib.pmcw.pam &
	383	sch->schib.pmcw.pom &
	384	sch->opm;
1da177e4 LT	385	__ccw_device_verify_start(cdev);
	386	}
	387
	388	static void
	389	__ccw_device_disband_start(struct ccw_device *cdev)
	390	{
	391	struct subchannel *sch;
	392	int ret;
	393
	394	sch = to_subchannel(cdev->dev.parent);
	395	while (cdev->private->imask != 0) {
	396	if (sch->lpm & cdev->private->imask) {
	397	ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
	398	if (ret == 0)
	399	return;
	400	}
	401	cdev->private->iretry = 5;
	402	cdev->private->imask >>= 1;
	403	}
	404	ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
	405	}
	406
	407	/*
	408	* Got interrupt for Unset Path Group ID.
	409	*/
	410	void
	411	ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
	412	{
	413	struct subchannel *sch;
	414	struct irb *irb;
	415	int ret;
	416
	417	irb = (struct irb *) __LC_IRB;
	418	/* Retry set pgid for cc=1. */
	419	if (irb->scsw.stctl ==
	420	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
	421	if (irb->scsw.cc == 1)
	422	__ccw_device_disband_start(cdev);
	423	return;
	424	}
	425	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	426	return;
	427	sch = to_subchannel(cdev->dev.parent);
	428	ret = __ccw_device_check_pgid(cdev);
	429	memset(&cdev->private->irb, 0, sizeof(struct irb));
	430	switch (ret) {
	431	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	432	case 0: /* disband successful. */
	433	sch->vpm = 0;
	434	ccw_device_disband_done(cdev, ret);
	435	break;
	436	case -EOPNOTSUPP:
	437	/*
	438	* One of those strange devices which claim to be able
	439	* to do multipathing but not for Unset Path Group ID.
	440	*/
	441	cdev->private->flags.pgid_single = 1;
	442	/* fall through. */
	443	case -EAGAIN: /* Try again. */
	444	__ccw_device_disband_start(cdev);
	445	break;
	446	case -ETIME: /* Set path group id stopped by timeout. */
	447	ccw_device_disband_done(cdev, -ETIME);
	448	break;
449	case -EACCES: /* channel is not operational. */
450	cdev->private->imask >>= 1;
451	cdev->private->iretry = 5;
452	__ccw_device_disband_start(cdev);
453	break;
454	}
455	}
456
457	void
458	ccw_device_disband_start(struct ccw_device *cdev)
459	{
460	cdev->private->flags.pgid_single = 0;
461	cdev->private->iretry = 5;
462	cdev->private->imask = 0x80;
463	__ccw_device_disband_start(cdev);
464	}