/*
 * 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.
 */

/*
 * 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);
}