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kernel-ark/drivers/s390/cio/device_pgid.c
Cornelia Huck 7e560814de [S390] path grouping and path verifications fixes. 
1. Multipath devices for which SetPGID is not supported are not handled well.
   Use NOP ccws for path verification (sans path grouping) when SetPGID is not
   supported.
2. Check for PGIDs already set with SensePGID on _all_ paths (not just the
   first one) and try to find a common one. Moan if no common PGID can be
   found (and use NOP verification). If no PGIDs have been set, use the css
   global PGID (as before). (Rationale: SetPGID will get a command reject if
   the PGID it tries to set does not match the already set PGID.)
3. Immediately before reboot, issue RESET CHANNEL PATH (rcp) on all chpids. This
   will remove the old PGIDs. rcp will generate solicited CRWs which can be
   savely ignored by the machine check handler (all other actions create
   unsolicited CRWs).

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-07-12 16:40:19 +02:00

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/*
* 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"
/*
* Start Sense Path Group ID helper function. Used in ccw_device_recog
* and ccw_device_sense_pgid.
*/
static int
__ccw_device_sense_pgid_start(struct ccw_device *cdev)
{
struct subchannel *sch;
struct ccw1 *ccw;
int ret;
int i;
sch = to_subchannel(cdev->dev.parent);
/* Return if we already checked on all paths. */
if (cdev->private->imask == 0)
return (sch->lpm == 0) ? -ENODEV : -EACCES;
i = 8 - ffs(cdev->private->imask);
/* Setup sense path group id channel program. */
ccw = cdev->private->iccws;
ccw->cmd_code = CCW_CMD_SENSE_PGID;
ccw->count = sizeof (struct pgid);
ccw->flags = CCW_FLAG_SLI;
/* Reset device status. */
memset(&cdev->private->irb, 0, sizeof(struct irb));
/* Try on every path. */
ret = -ENODEV;
while (cdev->private->imask != 0) {
/* Try every path multiple times. */
ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
if (cdev->private->iretry > 0) {
cdev->private->iretry--;
ret = cio_start (sch, cdev->private->iccws,
cdev->private->imask);
/* ret is 0, -EBUSY, -EACCES or -ENODEV */
if (ret != -EACCES)
return ret;
CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
"0.%x.%04x, lpm %02X, became 'not "
"operational'\n",
cdev->private->devno, sch->schid.ssid,
sch->schid.sch_no, cdev->private->imask);
}
cdev->private->imask >>= 1;
cdev->private->iretry = 5;
i++;
}
return ret;
}
void
ccw_device_sense_pgid_start(struct ccw_device *cdev)
{
int ret;
cdev->private->state = DEV_STATE_SENSE_PGID;
cdev->private->imask = 0x80;
cdev->private->iretry = 5;
memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
ret = __ccw_device_sense_pgid_start(cdev);
if (ret && ret != -EBUSY)
ccw_device_sense_pgid_done(cdev, ret);
}
/*
* Called from interrupt context to check if a valid answer
* to Sense Path Group ID was received.
*/
static int
__ccw_device_check_sense_pgid(struct ccw_device *cdev)
{
struct subchannel *sch;
struct irb *irb;
int i;
sch = to_subchannel(cdev->dev.parent);
irb = &cdev->private->irb;
if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
return -ETIME;
if (irb->esw.esw0.erw.cons &&
(irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
/*
* If the device doesn't support the Sense Path Group ID
* command further retries wouldn't help ...
*/
return -EOPNOTSUPP;
}
if (irb->esw.esw0.erw.cons) {
CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
"lpum %02X, cnt %02d, sns : "
"%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
cdev->private->ssid, cdev->private->devno,
irb->esw.esw0.sublog.lpum,
irb->esw.esw0.erw.scnt,
irb->ecw[0], irb->ecw[1],
irb->ecw[2], irb->ecw[3],
irb->ecw[4], irb->ecw[5],
irb->ecw[6], irb->ecw[7]);
return -EAGAIN;
}
if (irb->scsw.cc == 3) {
CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
" lpm %02X, became 'not operational'\n",
cdev->private->devno, sch->schid.ssid,
sch->schid.sch_no, sch->orb.lpm);
return -EACCES;
}
i = 8 - ffs(cdev->private->imask);
if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
"is reserved by someone else\n",
cdev->private->devno, sch->schid.ssid,
sch->schid.sch_no);
return -EUSERS;
}
return 0;
}
/*
* Got interrupt for Sense Path Group ID.
*/
void
ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
struct subchannel *sch;
struct irb *irb;
int ret;
irb = (struct irb *) __LC_IRB;
/* 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 -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 = -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 "
"0.%x.%04x, lpm %02X, became 'not operational'\n",
cdev->private->devno, sch->schid.ssid,
sch->schid.sch_no, cdev->private->imask);
return ret;
}
/*
* Helper function to send a nop ccw down a path.
*/
static int __ccw_device_do_nop(struct ccw_device *cdev)
{
struct subchannel *sch;
struct ccw1 *ccw;
int ret;
sch = to_subchannel(cdev->dev.parent);
/* Setup nop channel program. */
ccw = cdev->private->iccws;
ccw->cmd_code = CCW_CMD_NOOP;
ccw->cda = 0;
ccw->count = 0;
ccw->flags = CCW_FLAG_SLI;
/* Reset device status. */
memset(&cdev->private->irb, 0, sizeof(struct irb));
/* Try multiple times. */
ret = -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;
}
/* nop command failed on this path. Switch it off. */
sch->lpm &= ~cdev->private->imask;
sch->vpm &= ~cdev->private->imask;
CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
"0.%x.%04x, lpm %02X, became 'not operational'\n",
cdev->private->devno, sch->schid.ssid,
sch->schid.sch_no, cdev->private->imask);
return ret;
}
/*
* Called from interrupt context to check if a valid answer
* to Set Path Group ID was received.
*/
static int
__ccw_device_check_pgid(struct ccw_device *cdev)
{
struct subchannel *sch;
struct irb *irb;
sch = to_subchannel(cdev->dev.parent);
irb = &cdev->private->irb;
if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
return -ETIME;
if (irb->esw.esw0.erw.cons) {
if (irb->ecw[0] & SNS0_CMD_REJECT)
return -EOPNOTSUPP;
/* Hmm, whatever happened, try again. */
CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
"cnt %02d, "
"sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
cdev->private->ssid,
cdev->private->devno, irb->esw.esw0.erw.scnt,
irb->ecw[0], irb->ecw[1],
irb->ecw[2], irb->ecw[3],
irb->ecw[4], irb->ecw[5],
irb->ecw[6], irb->ecw[7]);
return -EAGAIN;
}
if (irb->scsw.cc == 3) {
CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
" lpm %02X, became 'not operational'\n",
cdev->private->devno, sch->schid.ssid,
sch->schid.sch_no, cdev->private->imask);
return -EACCES;
}
return 0;
}
/*
* Called from interrupt context to check the path status after a nop has
* been send.
*/
static int __ccw_device_check_nop(struct ccw_device *cdev)
{
struct subchannel *sch;
struct irb *irb;
sch = to_subchannel(cdev->dev.parent);
irb = &cdev->private->irb;
if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
return -ETIME;
if (irb->scsw.cc == 3) {
CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
" lpm %02X, became 'not operational'\n",
cdev->private->devno, sch->schid.ssid,
sch->schid.sch_no, cdev->private->imask);
return -EACCES;
}
return 0;
}
static void
__ccw_device_verify_start(struct ccw_device *cdev)
{
struct subchannel *sch;
__u8 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;
if (cdev->private->options.pgroup) {
func = (sch->vpm & imask) ?
SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
ret = __ccw_device_do_pgid(cdev, func);
} else
ret = __ccw_device_do_nop(cdev);
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);
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:
/* 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)
cdev->private->options.pgroup = 0;
else
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_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;
/* 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);
}
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