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linux/drivers/s390/cio/device_pgid.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2 
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

449 lines
12 KiB
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/*
* 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"
/*
* 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->irq,
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->irq, 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->irq);
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, &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->irq, 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->irq,
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)
{
cdev->private->flags.pgid_single = 0;
cdev->private->iretry = 5;
__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);
}
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