scsi_vhci/fops/tpgs.c

	tpgs.c revision 0205780bc43902d17f94f07ceacb0cd8d5eab20f
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Implementation of "scsi_vhci_f_tpgs" T10 standard based failover_ops.
 *
 * NOTE: for non-sequential devices only.
 */

#include <sys/conf.h>
#include <sys/file.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/scsi/scsi.h>
#include <sys/scsi/adapters/scsi_vhci.h>
#include <sys/scsi/adapters/scsi_vhci_tpgs.h>

/* Supported device table entries.  */
char    *std_dev_table[] = { NULL };

/* Failover module plumbing. */
SCSI_FAILOVER_OP(SFO_NAME_TPGS, std, "%I%");

#define STD_FO_CMD_RETRY_DELAY  1000000 /* 1 seconds */
#define STD_FO_RETRY_DELAY  2000000 /* 2 seconds */
/*
 * max time for failover to complete is 3 minutes.  Compute
 * number of retries accordingly, to ensure we wait for at least
 * 3 minutes
 */
#define STD_FO_MAX_RETRIES  (3*60*1000000)/STD_FO_RETRY_DELAY


/* ARGSUSED */
static int
std_device_probe(struct scsi_device *sd, struct scsi_inquiry *inq,
    void **ctpriv)
{
    int     mode, state, xlf, preferred = 0;

    VHCI_DEBUG(6, (CE_NOTE, NULL, "std_device_probe: vidpid %s\n",
        inq->inq_vid));

    if (inq->inq_tpgs == 0) {
        VHCI_DEBUG(4, (CE_WARN, NULL,
            "!std_device_probe: not a standard tpgs device"));
        return (SFO_DEVICE_PROBE_PHCI);
    }

    if (inq->inq_dtype == DTYPE_SEQUENTIAL) {
        VHCI_DEBUG(4, (CE_NOTE, NULL,
            "!std_device_probe: Detected a "
            "Standard Asymmetric device "
            "not yet supported\n"));
        return (SFO_DEVICE_PROBE_PHCI);
    }

    if (vhci_tpgs_get_target_fo_mode(sd, &mode, &state, &xlf, &preferred)) {
        VHCI_DEBUG(4, (CE_WARN, NULL, "!unable to fetch fo "
            "mode: sd(%p)", (void *) sd));
        return (SFO_DEVICE_PROBE_PHCI);
    }

    if (inq->inq_tpgs == SCSI_IMPLICIT_FAILOVER) {
        VHCI_DEBUG(1, (CE_NOTE, NULL,
            "!std_device_probe: Detected a "
            "Standard Asymmetric device "
            "with implicit failover\n"));
        return (SFO_DEVICE_PROBE_VHCI);
    }
    if (inq->inq_tpgs == SCSI_EXPLICIT_FAILOVER) {
        VHCI_DEBUG(1, (CE_NOTE, NULL,
            "!std_device_probe: Detected a "
            "Standard Asymmetric device "
            "with explicit failover\n"));
        return (SFO_DEVICE_PROBE_VHCI);
    }
    if (inq->inq_tpgs == SCSI_BOTH_FAILOVER) {
        VHCI_DEBUG(1, (CE_NOTE, NULL,
            "!std_device_probe: Detected a "
            "Standard Asymmetric device "
            "which supports both implicit and explicit failover\n"));
        return (SFO_DEVICE_PROBE_VHCI);
    }
    VHCI_DEBUG(1, (CE_WARN, NULL,
        "!std_device_probe: "
        "Unknown tpgs_bits: %x", inq->inq_tpgs));
    return (SFO_DEVICE_PROBE_PHCI);
}

/* ARGSUSED */
static void
std_device_unprobe(struct scsi_device *sd, void *ctpriv)
{
    /*
     * For future use
     */
}

/* ARGSUSED */
static int
std_activate_explicit(struct scsi_device *sd, int xlf_capable)
{
    cmn_err(CE_NOTE, "Explicit Activation is done by "
        "vhci_tpgs_set_target_groups() call from MPAPI");
    return (1);
}

/*
 * Process the packet reason of CMD_PKT_CMPLT - return 0 if no
 * retry and 1 if a retry should be done
 */
static int
std_process_cmplt_pkt(struct scsi_device *sd, struct scsi_pkt *pkt,
    int *retry_cnt)
{
    struct scsi_extended_sense  *sns;

    /*
     * Re-initialize retry_cmd_cnt. Allow transport and
     * cmd errors to go through a full retry count when
     * these are encountered.  This way TRAN/CMD errors
     * retry count is not exhausted due to CMD_CMPLTs
     * delay. This allows the system
     * to brave a hick-up on the link at any given time,
     * while waiting for the fo to complete.
     */
    if (pkt->pkt_state & STATE_ARQ_DONE) {
        sns = &(((struct scsi_arq_status *)(uintptr_t)
            (pkt->pkt_scbp))->sts_sensedata);
        if (sns->es_key == KEY_UNIT_ATTENTION) {
            /*
             * tpgs access state changed
             */
            if (sns->es_add_code == STD_SCSI_ASC_STATE_CHG &&
                sns->es_qual_code == STD_SCSI_ASCQ_STATE_CHG_SUCC) {
                /* XXX: update path info? */
                cmn_err(CE_WARN, "!Device failover"
                    " state change");
            }
            return (1);
        } else if (sns->es_key == KEY_NOT_READY) {
            if ((*retry_cnt)++ >=
                STD_FO_MAX_RETRIES) {
                cmn_err(CE_WARN, "!Device failover"
                    " failed: timed out waiting "
                    "for path to become active");
                return (0);
            }
            VHCI_DEBUG(6, (CE_NOTE, NULL,
                "!(sd:%p)lun "
                "becoming active...\n", (void *)sd));
            drv_usecwait(STD_FO_RETRY_DELAY);
            return (1);
        }
        cmn_err(CE_NOTE, "!Failover failed;"
            " sense key:%x, ASC: %x, "
            "ASCQ:%x", sns->es_key,
            sns->es_add_code, sns->es_qual_code);
        return (0);
    }
    switch (SCBP_C(pkt)) {
        case STATUS_GOOD:
            break;
        case STATUS_CHECK:
            VHCI_DEBUG(4, (CE_WARN, NULL,
                "!(sd:%p):"
                " status returned CHECK during std"
                " path activation", (void *)sd));
            return (0);
        case STATUS_QFULL:
            VHCI_DEBUG(6, (CE_NOTE, NULL, "QFULL "
                "status returned QFULL during std "
                "path activation for %p\n", (void *)sd));
            drv_usecwait(5000);
            return (1);
        case STATUS_BUSY:
            VHCI_DEBUG(6, (CE_NOTE, NULL, "BUSY "
                "status returned BUSY during std "
                "path activation for %p\n", (void *)sd));
            drv_usecwait(5000);
            return (1);
        default:
            VHCI_DEBUG(4, (CE_WARN, NULL,
                "!(sd:%p) Bad status returned during std "
                "activation (pkt %p, status %x)",
                (void *)sd, (void *)pkt, SCBP_C(pkt)));
            return (0);
    }
    return (0);
}

/*
 * For now we are going to use primary/online and secondary/online.
 * There is no standby path returned by the dsp and we may have
 * to do something different for other devices that use standby
 */
/* ARGSUSED */
static int
std_path_activate(struct scsi_device *sd, char *pathclass,
    void *ctpriv)
{
    struct buf          *bp;
    struct scsi_pkt         *pkt;
    struct scsi_address     *ap;
    int             err, retry_cnt, retry_cmd_cnt;
    int             mode, state, retval, xlf, preferred;

    ap = &sd->sd_address;

    mode = state = 0;

    if (vhci_tpgs_get_target_fo_mode(sd, &mode, &state, &xlf, &preferred)) {
        VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_path_activate:"
            " failed vhci_tpgs_get_target_fo_mode\n"));
        return (1);
    }
    if ((state == STD_ACTIVE_OPTIMIZED) ||
        (state == STD_ACTIVE_NONOPTIMIZED)) {
        VHCI_DEBUG(4, (CE_NOTE, NULL, "!path already active for %p\n",
            (void *)sd));
        return (0);
    }

    if (mode != SCSI_IMPLICIT_FAILOVER) {
        VHCI_DEBUG(4, (CE_NOTE, NULL,
            "!mode is EXPLICIT for %p xlf %x\n",
            (void *)sd, xlf));
        retval = std_activate_explicit(sd, xlf);
        if (retval != 0) {
            VHCI_DEBUG(4, (CE_NOTE, NULL,
                "!(sd:%p)std_path_activate failed(1)\n",
                (void *)sd));
            return (1);
        }
    } else {
        VHCI_DEBUG(4, (CE_NOTE, NULL, "STD mode is IMPLICIT for %p\n",
            (void *)sd));
    }

    bp = scsi_alloc_consistent_buf(ap, (struct buf *)NULL, DEV_BSIZE,
        B_READ, NULL, NULL);
    if (!bp) {
        VHCI_DEBUG(4, (CE_WARN, NULL,
            "!(sd:%p)std_path_activate failed to alloc buffer",
            (void *)sd));
        return (1);
    }

    pkt = scsi_init_pkt(ap, NULL, bp, CDB_GROUP1,
        sizeof (struct scsi_arq_status), 0, PKT_CONSISTENT, NULL, NULL);
    if (!pkt) {
        VHCI_DEBUG(4, (CE_WARN, NULL,
            "!(sd:%p)std_path_activate failed to initialize packet",
            (void *)sd));
        scsi_free_consistent_buf(bp);
        return (1);
    }

    (void) scsi_setup_cdb((union scsi_cdb *)(uintptr_t)pkt->pkt_cdbp,
        SCMD_READ, 1, 1, 0);
    pkt->pkt_time = 3*30;
    pkt->pkt_flags |= FLAG_NOINTR;

    retry_cnt = 0;
    retry_cmd_cnt = 0;
retry:
    err = scsi_transport(pkt);
    if (err != TRAN_ACCEPT) {
        /*
         * Retry TRAN_BUSY till STD_FO_MAX_RETRIES is exhausted.
         * All other errors are fatal and should not be retried.
         */
        if ((err == TRAN_BUSY) &&
            (retry_cnt++ < STD_FO_MAX_RETRIES)) {
            drv_usecwait(STD_FO_RETRY_DELAY);
            goto retry;
        }
        cmn_err(CE_WARN, "Failover failed, "
            "couldn't transport packet");
        scsi_destroy_pkt(pkt);
        scsi_free_consistent_buf(bp);
        return (1);
    }
    switch (pkt->pkt_reason) {
        case CMD_CMPLT:
            retry_cmd_cnt = 0;
            retval = std_process_cmplt_pkt(sd, pkt, &retry_cnt);
            if (retval != 0) {
                goto retry;
            }
            break;
        case CMD_TIMEOUT:
            cmn_err(CE_WARN, "!Failover failed: timed out ");
            retval = 1;
            break;
        case CMD_INCOMPLETE:
        case CMD_RESET:
        case CMD_ABORTED:
        case CMD_TRAN_ERR:
            /*
             * Increased the number of retries when these error
             * cases are encountered.  Also added a 1 sec wait
             * before retrying.
             */
            if (retry_cmd_cnt++ < STD_FO_MAX_CMD_RETRIES) {
                drv_usecwait(STD_FO_CMD_RETRY_DELAY);
                VHCI_DEBUG(4, (CE_WARN, NULL,
                    "!Retrying path activation due to "
                    "pkt reason:%x, retry cnt:%d",
                    pkt->pkt_reason, retry_cmd_cnt));
                goto retry;
            }
            /* FALLTHROUGH */
        default:
            cmn_err(CE_WARN, "!Path activation did not "
                "complete successfully,"
                "(pkt reason %x)", pkt->pkt_reason);
            retval = 1;
            break;
    }


    VHCI_DEBUG(4, (CE_NOTE, NULL, "!Path activation success\n"));
    scsi_destroy_pkt(pkt);
    scsi_free_consistent_buf(bp);
    return (retval);
}

/* ARGSUSED */
static int std_path_deactivate(struct scsi_device *sd, char *pathclass,
    void *ctpriv)
{
    return (0);
}

/* ARGSUSED */
static int
std_path_get_opinfo(struct scsi_device *sd, struct scsi_path_opinfo *opinfo,
    void *ctpriv)
{
    int         mode, preferred, state, xlf;

    opinfo->opinfo_rev = OPINFO_REV;

    if (vhci_tpgs_get_target_fo_mode(sd, &mode, &state, &xlf, &preferred)) {
        VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_path_getopinfo:"
            " failed vhci_tpgs_get_target_fo_mode\n"));
        return (1);
    }

    if (state == STD_ACTIVE_OPTIMIZED) {
        opinfo->opinfo_path_state = SCSI_PATH_ACTIVE;
    } else if (state == STD_ACTIVE_NONOPTIMIZED) {
        opinfo->opinfo_path_state = SCSI_PATH_ACTIVE_NONOPT;
    } else if (state == STD_STANDBY) {
        opinfo->opinfo_path_state = SCSI_PATH_INACTIVE;
    } else if (state == STD_UNAVAILABLE) {
        opinfo->opinfo_path_state = SCSI_PATH_INACTIVE;
    }
    if (preferred) {
        (void) strcpy(opinfo->opinfo_path_attr, PCLASS_PRIMARY);
    } else {
        (void) strcpy(opinfo->opinfo_path_attr, PCLASS_SECONDARY);
    }
    VHCI_DEBUG(4, (CE_NOTE, NULL, "std_path_get_opinfo: "
        "class: %s state: %s\n", opinfo->opinfo_path_attr,
        opinfo->opinfo_path_state == SCSI_PATH_ACTIVE ?
        "ACTIVE" : "INACTIVE"));
    opinfo->opinfo_xlf_capable = 0;
    opinfo->opinfo_pswtch_best = 30;
    opinfo->opinfo_pswtch_worst = 3*30;
    opinfo->opinfo_preferred = (uint16_t)preferred;
    opinfo->opinfo_mode = (uint16_t)mode;

    return (0);
}

/* ARGSUSED */
static int std_path_ping(struct scsi_device *sd, void *ctpriv)
{
    /*
     * For future use
     */
    return (1);
}

/*
 * Analyze the sense code to determine whether failover process
 */
/* ARGSUSED */
static int
std_analyze_sense(struct scsi_device *sd, struct scsi_extended_sense *sense,
    void *ctpriv)
{
    int rval = SCSI_SENSE_UNKNOWN;

    if ((sense->es_key == KEY_UNIT_ATTENTION) &&
        (sense->es_add_code == STD_SCSI_ASC_STATE_CHG) &&
        (sense->es_qual_code == STD_SCSI_ASCQ_STATE_CHG_SUCC)) {
        rval = SCSI_SENSE_STATE_CHANGED;
        VHCI_DEBUG(4, (CE_NOTE, NULL, "!std_analyze_sense:"
            " sense_key:%x, add_code: %x, qual_code:%x"
            " sense:%x\n", sense->es_key, sense->es_add_code,
            sense->es_qual_code, rval));
    } else if ((sense->es_key == KEY_NOT_READY) &&
        (sense->es_add_code == STD_LOGICAL_UNIT_NOT_ACCESSIBLE) &&
        (sense->es_qual_code == STD_TGT_PORT_UNAVAILABLE)) {
        rval = SCSI_SENSE_INACTIVE;
        VHCI_DEBUG(4, (CE_NOTE, NULL, "!std_analyze_sense:"
            " sense_key:%x, add_code: %x, qual_code:%x"
            " sense:%x\n", sense->es_key, sense->es_add_code,
            sense->es_qual_code, rval));
    } else if ((sense->es_key == KEY_ILLEGAL_REQUEST) &&
        (sense->es_add_code == STD_SCSI_ASC_INVAL_PARAM_LIST)) {
        rval = SCSI_SENSE_NOFAILOVER;
        VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_analyze_sense:"
            " sense_key:%x, add_code: %x, qual_code:%x"
            " sense:%x\n", sense->es_key, sense->es_add_code,
            sense->es_qual_code, rval));
    } else if ((sense->es_key == KEY_ILLEGAL_REQUEST) &&
        (sense->es_add_code == STD_SCSI_ASC_INVAL_CMD_OPCODE)) {
        rval = SCSI_SENSE_NOFAILOVER;
        VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_analyze_sense:"
            " sense_key:%x, add_code: %x, qual_code:%x"
            " sense:%x\n", sense->es_key, sense->es_add_code,
            sense->es_qual_code, rval));
    } else {
        /*
         * At this point sense data may be for power-on-reset
         * UNIT ATTN hardware errors, vendor unqiue sense data etc.
         * For all these cases, return SCSI_SENSE_UNKNOWN.
         */
        VHCI_DEBUG(1, (CE_NOTE, NULL, "!Analyze sense UNKNOWN:"
            " sense key:%x, ASC:%x, ASCQ:%x\n", sense->es_key,
            sense->es_add_code, sense->es_qual_code));
    }

    return (rval);
}

/* ARGSUSED */
static int
std_pathclass_next(char *cur, char **nxt, void *ctpriv)
{
    /*
     * The first phase does not have a standby path so
     * there will be no explicit failover - when standard tpgs.
     * standard defines preferred flag then we should start
     * using this as the selection mechanism - there can be
     * preferred primary standby that we should fail to first and then
     * nonpreferred secondary standby.
     */
    if (cur == NULL) {
        *nxt = PCLASS_PRIMARY;
        return (0);
    } else if (strcmp(cur, PCLASS_PRIMARY) == 0) {
        *nxt = PCLASS_SECONDARY;
        return (0);
    } else if (strcmp(cur, PCLASS_SECONDARY) == 0) {
        return (ENOENT);
    } else {
        return (EINVAL);
    }
}