NetBSD/sys/dev/dmover/dmover_session.c

138 lines
3.9 KiB
C

/* $NetBSD: dmover_session.c,v 1.2 2005/02/27 00:26:59 perry 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 1.2 2005/02/27 00:26:59 perry Exp $");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/pool.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <dev/dmover/dmovervar.h>
struct pool dmover_session_pool;
static int initialized;
static struct simplelock initialized_slock = SIMPLELOCK_INITIALIZER;
void
dmover_session_initialize(void)
{
simple_lock(&initialized_slock);
if (__predict_true(initialized == 0)) {
pool_init(&dmover_session_pool, sizeof(struct dmover_session),
0, 0, 0, "dmses", &pool_allocator_nointr);
initialized = 1;
}
simple_unlock(&initialized_slock);
}
/*
* 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 == 0)) {
simple_lock(&initialized_slock);
error = initialized ? 0 : ENXIO;
simple_unlock(&initialized_slock);
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)
{
#ifdef DIAGNOSTIC
if (__predict_false(initialized == 0)) {
int croak;
simple_lock(&initialized_slock);
croak = (initialized == 0);
simple_unlock(&initialized_slock);
if (croak)
panic("dmover_session_destroy: not initialized");
}
#endif
/* XXX */
if (dses->__dses_npendreqs)
panic("dmover_session_destroy");
dmover_backend_release(dses);
pool_put(&dmover_session_pool, dses);
}