device_status.c

Go to the documentation of this file.

/*
 *    Copyright IBM Corp. 2002
 *    Author(s): Cornelia Huck ([email protected])
 *       Martin Schwidefsky ([email protected])
 *
 * Status accumulation and basic sense functions.
 */

#include <linux/module.h>
#include <linux/init.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"
#include "io_sch.h"

/*
 * Check for any kind of channel or interface control check but don't
 * issue the message for the console device
 */
static void
ccw_device_msg_control_check(struct ccw_device *cdev, struct irb *irb)
{
    char dbf_text[15];

    if (!scsw_is_valid_cstat(&irb->scsw) ||
        !(scsw_cstat(&irb->scsw) & (SCHN_STAT_CHN_DATA_CHK |
          SCHN_STAT_CHN_CTRL_CHK | SCHN_STAT_INTF_CTRL_CHK)))
        return;
    CIO_MSG_EVENT(0, "Channel-Check or Interface-Control-Check "
              "received"
              " ... device %04x on subchannel 0.%x.%04x, dev_stat "
              ": %02X sch_stat : %02X\n",
              cdev->private->dev_id.devno, cdev->private->schid.ssid,
              cdev->private->schid.sch_no,
              scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw));
    sprintf(dbf_text, "chk%x", cdev->private->schid.sch_no);
    CIO_TRACE_EVENT(0, dbf_text);
    CIO_HEX_EVENT(0, irb, sizeof(struct irb));
}

/*
 * Some paths became not operational (pno bit in scsw is set).
 */
static void
ccw_device_path_notoper(struct ccw_device *cdev)
{
    struct subchannel *sch;

    sch = to_subchannel(cdev->dev.parent);
    if (cio_update_schib(sch))
        goto doverify;

    CIO_MSG_EVENT(0, "%s(0.%x.%04x) - path(s) %02x are "
              "not operational \n", __func__,
              sch->schid.ssid, sch->schid.sch_no,
              sch->schib.pmcw.pnom);

    sch->lpm &= ~sch->schib.pmcw.pnom;
doverify:
    cdev->private->flags.doverify = 1;
}

/*
 * Copy valid bits from the extended control word to device irb.
 */
static void
ccw_device_accumulate_ecw(struct ccw_device *cdev, struct irb *irb)
{
    /*
     * Copy extended control bit if it is valid... yes there
     * are condition that have to be met for the extended control
     * bit to have meaning. Sick.
     */
    cdev->private->irb.scsw.cmd.ectl = 0;
    if ((irb->scsw.cmd.stctl & SCSW_STCTL_ALERT_STATUS) &&
        !(irb->scsw.cmd.stctl & SCSW_STCTL_INTER_STATUS))
        cdev->private->irb.scsw.cmd.ectl = irb->scsw.cmd.ectl;
    /* Check if extended control word is valid. */
    if (!cdev->private->irb.scsw.cmd.ectl)
        return;
    /* Copy concurrent sense / model dependent information. */
    memcpy (&cdev->private->irb.ecw, irb->ecw, sizeof (irb->ecw));
}

/*
 * Check if extended status word is valid.
 */
static int
ccw_device_accumulate_esw_valid(struct irb *irb)
{
    if (!irb->scsw.cmd.eswf &&
        (irb->scsw.cmd.stctl == SCSW_STCTL_STATUS_PEND))
        return 0;
    if (irb->scsw.cmd.stctl ==
            (SCSW_STCTL_INTER_STATUS|SCSW_STCTL_STATUS_PEND) &&
        !(irb->scsw.cmd.actl & SCSW_ACTL_SUSPENDED))
        return 0;
    return 1;
}

/*
 * Copy valid bits from the extended status word to device irb.
 */
static void
ccw_device_accumulate_esw(struct ccw_device *cdev, struct irb *irb)
{
    struct irb *cdev_irb;
    struct sublog *cdev_sublog, *sublog;

    if (!ccw_device_accumulate_esw_valid(irb))
        return;

    cdev_irb = &cdev->private->irb;

    /* Copy last path used mask. */
    cdev_irb->esw.esw1.lpum = irb->esw.esw1.lpum;

    /* Copy subchannel logout information if esw is of format 0. */
    if (irb->scsw.cmd.eswf) {
        cdev_sublog = &cdev_irb->esw.esw0.sublog;
        sublog = &irb->esw.esw0.sublog;
        /* Copy extended status flags. */
        cdev_sublog->esf = sublog->esf;
        /*
         * Copy fields that have a meaning for channel data check
         * channel control check and interface control check.
         */
        if (irb->scsw.cmd.cstat & (SCHN_STAT_CHN_DATA_CHK |
                       SCHN_STAT_CHN_CTRL_CHK |
                       SCHN_STAT_INTF_CTRL_CHK)) {
            /* Copy ancillary report bit. */
            cdev_sublog->arep = sublog->arep;
            /* Copy field-validity-flags. */
            cdev_sublog->fvf = sublog->fvf;
            /* Copy storage access code. */
            cdev_sublog->sacc = sublog->sacc;
            /* Copy termination code. */
            cdev_sublog->termc = sublog->termc;
            /* Copy sequence code. */
            cdev_sublog->seqc = sublog->seqc;
        }
        /* Copy device status check. */
        cdev_sublog->devsc = sublog->devsc;
        /* Copy secondary error. */
        cdev_sublog->serr = sublog->serr;
        /* Copy i/o-error alert. */
        cdev_sublog->ioerr = sublog->ioerr;
        /* Copy channel path timeout bit. */
        if (irb->scsw.cmd.cstat & SCHN_STAT_INTF_CTRL_CHK)
            cdev_irb->esw.esw0.erw.cpt = irb->esw.esw0.erw.cpt;
        /* Copy failing storage address validity flag. */
        cdev_irb->esw.esw0.erw.fsavf = irb->esw.esw0.erw.fsavf;
        if (cdev_irb->esw.esw0.erw.fsavf) {
            /* ... and copy the failing storage address. */
            memcpy(cdev_irb->esw.esw0.faddr, irb->esw.esw0.faddr,
                   sizeof (irb->esw.esw0.faddr));
            /* ... and copy the failing storage address format. */
            cdev_irb->esw.esw0.erw.fsaf = irb->esw.esw0.erw.fsaf;
        }
        /* Copy secondary ccw address validity bit. */
        cdev_irb->esw.esw0.erw.scavf = irb->esw.esw0.erw.scavf;
        if (irb->esw.esw0.erw.scavf)
            /* ... and copy the secondary ccw address. */
            cdev_irb->esw.esw0.saddr = irb->esw.esw0.saddr;
        
    }
    /* FIXME: DCTI for format 2? */

    /* Copy authorization bit. */
    cdev_irb->esw.esw0.erw.auth = irb->esw.esw0.erw.auth;
    /* Copy path verification required flag. */
    cdev_irb->esw.esw0.erw.pvrf = irb->esw.esw0.erw.pvrf;
    if (irb->esw.esw0.erw.pvrf)
        cdev->private->flags.doverify = 1;
    /* Copy concurrent sense bit. */
    cdev_irb->esw.esw0.erw.cons = irb->esw.esw0.erw.cons;
    if (irb->esw.esw0.erw.cons)
        cdev_irb->esw.esw0.erw.scnt = irb->esw.esw0.erw.scnt;
}

/*
 * Accumulate status from irb to devstat.
 */
void
ccw_device_accumulate_irb(struct ccw_device *cdev, struct irb *irb)
{
    struct irb *cdev_irb;

    /*
     * Check if the status pending bit is set in stctl.
     * If not, the remaining bit have no meaning and we must ignore them.
     * The esw is not meaningful as well...
     */
    if (!(scsw_stctl(&irb->scsw) & SCSW_STCTL_STATUS_PEND))
        return;

    /* Check for channel checks and interface control checks. */
    ccw_device_msg_control_check(cdev, irb);

    /* Check for path not operational. */
    if (scsw_is_valid_pno(&irb->scsw) && scsw_pno(&irb->scsw))
        ccw_device_path_notoper(cdev);
    /* No irb accumulation for transport mode irbs. */
    if (scsw_is_tm(&irb->scsw)) {
        memcpy(&cdev->private->irb, irb, sizeof(struct irb));
        return;
    }
    /*
     * Don't accumulate unsolicited interrupts.
     */
    if (!scsw_is_solicited(&irb->scsw))
        return;

    cdev_irb = &cdev->private->irb;

    /*
     * If the clear function had been performed, all formerly pending
     * status at the subchannel has been cleared and we must not pass
     * intermediate accumulated status to the device driver.
     */
    if (irb->scsw.cmd.fctl & SCSW_FCTL_CLEAR_FUNC)
        memset(&cdev->private->irb, 0, sizeof(struct irb));

    /* Copy bits which are valid only for the start function. */
    if (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) {
        /* Copy key. */
        cdev_irb->scsw.cmd.key = irb->scsw.cmd.key;
        /* Copy suspend control bit. */
        cdev_irb->scsw.cmd.sctl = irb->scsw.cmd.sctl;
        /* Accumulate deferred condition code. */
        cdev_irb->scsw.cmd.cc |= irb->scsw.cmd.cc;
        /* Copy ccw format bit. */
        cdev_irb->scsw.cmd.fmt = irb->scsw.cmd.fmt;
        /* Copy prefetch bit. */
        cdev_irb->scsw.cmd.pfch = irb->scsw.cmd.pfch;
        /* Copy initial-status-interruption-control. */
        cdev_irb->scsw.cmd.isic = irb->scsw.cmd.isic;
        /* Copy address limit checking control. */
        cdev_irb->scsw.cmd.alcc = irb->scsw.cmd.alcc;
        /* Copy suppress suspend bit. */
        cdev_irb->scsw.cmd.ssi = irb->scsw.cmd.ssi;
    }

    /* Take care of the extended control bit and extended control word. */
    ccw_device_accumulate_ecw(cdev, irb);
        
    /* Accumulate function control. */
    cdev_irb->scsw.cmd.fctl |= irb->scsw.cmd.fctl;
    /* Copy activity control. */
    cdev_irb->scsw.cmd.actl = irb->scsw.cmd.actl;
    /* Accumulate status control. */
    cdev_irb->scsw.cmd.stctl |= irb->scsw.cmd.stctl;
    /*
     * Copy ccw address if it is valid. This is a bit simplified
     * but should be close enough for all practical purposes.
     */
    if ((irb->scsw.cmd.stctl & SCSW_STCTL_PRIM_STATUS) ||
        ((irb->scsw.cmd.stctl ==
          (SCSW_STCTL_INTER_STATUS|SCSW_STCTL_STATUS_PEND)) &&
         (irb->scsw.cmd.actl & SCSW_ACTL_DEVACT) &&
         (irb->scsw.cmd.actl & SCSW_ACTL_SCHACT)) ||
        (irb->scsw.cmd.actl & SCSW_ACTL_SUSPENDED))
        cdev_irb->scsw.cmd.cpa = irb->scsw.cmd.cpa;
    /* Accumulate device status, but not the device busy flag. */
    cdev_irb->scsw.cmd.dstat &= ~DEV_STAT_BUSY;
    /* dstat is not always valid. */
    if (irb->scsw.cmd.stctl &
        (SCSW_STCTL_PRIM_STATUS | SCSW_STCTL_SEC_STATUS
         | SCSW_STCTL_INTER_STATUS | SCSW_STCTL_ALERT_STATUS))
        cdev_irb->scsw.cmd.dstat |= irb->scsw.cmd.dstat;
    /* Accumulate subchannel status. */
    cdev_irb->scsw.cmd.cstat |= irb->scsw.cmd.cstat;
    /* Copy residual count if it is valid. */
    if ((irb->scsw.cmd.stctl & SCSW_STCTL_PRIM_STATUS) &&
        (irb->scsw.cmd.cstat & ~(SCHN_STAT_PCI | SCHN_STAT_INCORR_LEN))
         == 0)
        cdev_irb->scsw.cmd.count = irb->scsw.cmd.count;

    /* Take care of bits in the extended status word. */
    ccw_device_accumulate_esw(cdev, irb);

    /*
     * Check whether we must issue a SENSE CCW ourselves if there is no
     * concurrent sense facility installed for the subchannel.
     * No sense is required if no delayed sense is pending
     * and we did not get a unit check without sense information.
     *
     * Note: We should check for ioinfo[irq]->flags.consns but VM
     *   violates the ESA/390 architecture and doesn't present an
     *   operand exception for virtual devices without concurrent
     *   sense facility available/supported when enabling the
     *   concurrent sense facility.
     */
    if ((cdev_irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
        !(cdev_irb->esw.esw0.erw.cons))
        cdev->private->flags.dosense = 1;
}

/*
 * Do a basic sense.
 */
int
ccw_device_do_sense(struct ccw_device *cdev, struct irb *irb)
{
    struct subchannel *sch;
    struct ccw1 *sense_ccw;
    int rc;

    sch = to_subchannel(cdev->dev.parent);

    /* A sense is required, can we do it now ? */
    if (scsw_actl(&irb->scsw) & (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT))
        /*
         * we received an Unit Check but we have no final
         *  status yet, therefore we must delay the SENSE
         *  processing. We must not report this intermediate
         *  status to the device interrupt handler.
         */
        return -EBUSY;

    /*
     * We have ending status but no sense information. Do a basic sense.
     */
    sense_ccw = &to_io_private(sch)->sense_ccw;
    sense_ccw->cmd_code = CCW_CMD_BASIC_SENSE;
    sense_ccw->cda = (__u32) __pa(cdev->private->irb.ecw);
    sense_ccw->count = SENSE_MAX_COUNT;
    sense_ccw->flags = CCW_FLAG_SLI;

    rc = cio_start(sch, sense_ccw, 0xff);
    if (rc == -ENODEV || rc == -EACCES)
        dev_fsm_event(cdev, DEV_EVENT_VERIFY);
    return rc;
}

/*
 * Add information from basic sense to devstat.
 */
void
ccw_device_accumulate_basic_sense(struct ccw_device *cdev, struct irb *irb)
{
    /*
     * Check if the status pending bit is set in stctl.
     * If not, the remaining bit have no meaning and we must ignore them.
     * The esw is not meaningful as well...
     */
    if (!(scsw_stctl(&irb->scsw) & SCSW_STCTL_STATUS_PEND))
        return;

    /* Check for channel checks and interface control checks. */
    ccw_device_msg_control_check(cdev, irb);

    /* Check for path not operational. */
    if (scsw_is_valid_pno(&irb->scsw) && scsw_pno(&irb->scsw))
        ccw_device_path_notoper(cdev);

    if (!(irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
        (irb->scsw.cmd.dstat & DEV_STAT_CHN_END)) {
        cdev->private->irb.esw.esw0.erw.cons = 1;
        cdev->private->flags.dosense = 0;
    }
    /* Check if path verification is required. */
    if (ccw_device_accumulate_esw_valid(irb) &&
        irb->esw.esw0.erw.pvrf)
        cdev->private->flags.doverify = 1;
}

/*
 * This function accumulates the status into the private devstat and
 * starts a basic sense if one is needed.
 */
int
ccw_device_accumulate_and_sense(struct ccw_device *cdev, struct irb *irb)
{
    ccw_device_accumulate_irb(cdev, irb);
    if ((irb->scsw.cmd.actl  & (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) != 0)
        return -EBUSY;
    /* Check for basic sense. */
    if (cdev->private->flags.dosense &&
        !(irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)) {
        cdev->private->irb.esw.esw0.erw.cons = 1;
        cdev->private->flags.dosense = 0;
        return 0;
    }
    if (cdev->private->flags.dosense) {
        ccw_device_do_sense(cdev, irb);
        return -EBUSY;
    }
    return 0;
}