/*      $NetBSD: dmover_session.c,v 1.6 2011/05/14 18:24:47 jakllsch Exp $      */

/*
* Copyright (c) 2002 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Jason R. Thorpe for Wasabi Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed for the NetBSD Project by
*      Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
*    or promote products derived from this software without specific prior
*    written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/*
* dmover_session.c: Session management functions for dmover-api.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: dmover_session.c,v 1.6 2011/05/14 18:24:47 jakllsch Exp $");

#include <sys/param.h>
#include <sys/pool.h>
#include <sys/systm.h>
#include <sys/malloc.h>

#include <dev/dmover/dmovervar.h>

struct pool dmover_session_pool;

static bool initialized;

void
dmover_session_initialize(void)
{

       KASSERT(initialized == false);

       pool_init(&dmover_session_pool, sizeof(struct dmover_session),
           0, 0, 0, "dmses", &pool_allocator_nointr, IPL_NONE);
       initialized = true;
}

/*
* dmover_session_create:       [client interface function]
*
*      Create a dmover session.
*/
int
dmover_session_create(const char *type, struct dmover_session **dsesp)
{
       struct dmover_session *dses;
       int error;

       if (__predict_false(initialized == false)) {
               error = initialized ? false : ENXIO;

               if (error)
                       return (error);
       }

       dses = pool_get(&dmover_session_pool, PR_NOWAIT);
       if (__predict_false(dses == NULL))
               return (ENOMEM);

       /* Allocate a back-end to the session. */
       error = dmover_backend_alloc(dses, type);
       if (__predict_false(error)) {
               pool_put(&dmover_session_pool, dses);
               return (error);
       }

       TAILQ_INIT(&dses->__dses_pendreqs);
       dses->__dses_npendreqs = 0;

       *dsesp = dses;
       return (0);
}

/*
* dmover_session_destroy:      [client interface function]
*
*      Tear down a dmover session.
*/
void
dmover_session_destroy(struct dmover_session *dses)
{

       KASSERT(initialized == true);

       /* XXX */
       if (dses->__dses_npendreqs)
               panic("dmover_session_destroy");

       dmover_backend_release(dses);
       pool_put(&dmover_session_pool, dses);
}