scsi/impl/scsi_reset_notify.c

	scsi_reset_notify.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 (c) 1998 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * support functions for hba drivers to handle scsi reset notifications.
 */

#include <sys/scsi/scsi.h>
#include <sys/scsi/impl/scsi_reset_notify.h>

/*
 * routine for reset notification setup.
 * The function is entered without adapter driver mutex being held.
 */

int
scsi_hba_reset_notify_setup(struct scsi_address *ap, int flag,
    void (*callback)(caddr_t), caddr_t arg, kmutex_t *mutex,
    struct scsi_reset_notify_entry **listp)
{
    struct scsi_reset_notify_entry  *p, *beforep;
    int             rval = DDI_FAILURE;

    mutex_enter(mutex);
    p = *listp;
    beforep = NULL;
    while (p) {
        if (p->ap == ap)
            break;      /* An entry exist for this target */
        beforep = p;
        p = p->next;
    }

    if ((flag & SCSI_RESET_CANCEL) && (p != NULL)) {
        if (beforep == NULL) {
            *listp = p->next;
        } else {
            beforep->next = p->next;
        }
        kmem_free(p, sizeof (struct scsi_reset_notify_entry));
        rval = DDI_SUCCESS;

    } else if ((flag & SCSI_RESET_NOTIFY) && (p == NULL)) {
        p = kmem_zalloc(sizeof (struct scsi_reset_notify_entry),
            KM_SLEEP);
        p->ap = ap;
        p->callback = callback;
        p->arg = arg;
        p->next = *listp;
        *listp = p;
        rval = DDI_SUCCESS;
    }
    mutex_exit(mutex);
    return (rval);
}

/*
 * routine to deallocate the callback list
 */
void
scsi_hba_reset_notify_tear_down(struct scsi_reset_notify_entry *listp)
{
    struct scsi_reset_notify_entry  *p, *next;

    p = listp;
    while (p) {
        next = p->next;
        kmem_free(p, sizeof (struct scsi_reset_notify_entry));
        p = next;
    }
}


/*
 * routine to perform the notification callbacks after a reset.
 * The function is entered with adapter driver mutex being held.
 */
void
scsi_hba_reset_notify_callback(kmutex_t *mutex,
    struct scsi_reset_notify_entry **listp)
{
    int i, count;
    struct  scsi_reset_notify_entry *p;
    struct  notify_entry {
        void    (*callback)(caddr_t);
        caddr_t arg;
    } *list;

    if ((p = *listp) == NULL)
        return;

    count = 0;
    while (p != NULL) {
        count++;
        p = p->next;
    }

    list = kmem_alloc(count * sizeof (struct notify_entry), KM_NOSLEEP);
    if (list == NULL) {
        cmn_err(CE_WARN, "scsi_reset_notify: kmem_alloc failed");
        return;
    }

    for (i = 0, p = *listp; i < count; i++, p = p->next) {
        list[i].callback = p->callback;
        list[i].arg = p->arg;
    }

    mutex_exit(mutex);
    for (i = 0; i < count; i++) {
        if (list[i].callback != NULL)
            (void) (*list[i].callback)(list[i].arg);
    }
    kmem_free(list, count * sizeof (struct notify_entry));
    mutex_enter(mutex);
}