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      1 /*	$NetBSD: dmover_session.c,v 1.6 2011/05/14 18:24:47 jakllsch Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2002 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed for the NetBSD Project by
     20  *	Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 /*
     39  * dmover_session.c: Session management functions for dmover-api.
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: dmover_session.c,v 1.6 2011/05/14 18:24:47 jakllsch Exp $");
     44 
     45 #include <sys/param.h>
     46 #include <sys/pool.h>
     47 #include <sys/systm.h>
     48 #include <sys/malloc.h>
     49 
     50 #include <dev/dmover/dmovervar.h>
     51 
     52 struct pool dmover_session_pool;
     53 
     54 static bool initialized;
     55 
     56 void
     57 dmover_session_initialize(void)
     58 {
     59 
     60 	KASSERT(initialized == false);
     61 
     62 	pool_init(&dmover_session_pool, sizeof(struct dmover_session),
     63 	    0, 0, 0, "dmses", &pool_allocator_nointr, IPL_NONE);
     64 	initialized = true;
     65 }
     66 
     67 /*
     68  * dmover_session_create:	[client interface function]
     69  *
     70  *	Create a dmover session.
     71  */
     72 int
     73 dmover_session_create(const char *type, struct dmover_session **dsesp)
     74 {
     75 	struct dmover_session *dses;
     76 	int error;
     77 
     78 	if (__predict_false(initialized == false)) {
     79 		error = initialized ? false : ENXIO;
     80 
     81 		if (error)
     82 			return (error);
     83 	}
     84 
     85 	dses = pool_get(&dmover_session_pool, PR_NOWAIT);
     86 	if (__predict_false(dses == NULL))
     87 		return (ENOMEM);
     88 
     89 	/* Allocate a back-end to the session. */
     90 	error = dmover_backend_alloc(dses, type);
     91 	if (__predict_false(error)) {
     92 		pool_put(&dmover_session_pool, dses);
     93 		return (error);
     94 	}
     95 
     96 	TAILQ_INIT(&dses->__dses_pendreqs);
     97 	dses->__dses_npendreqs = 0;
     98 
     99 	*dsesp = dses;
    100 	return (0);
    101 }
    102 
    103 /*
    104  * dmover_session_destroy:	[client interface function]
    105  *
    106  *	Tear down a dmover session.
    107  */
    108 void
    109 dmover_session_destroy(struct dmover_session *dses)
    110 {
    111 
    112 	KASSERT(initialized == true);
    113 
    114 	/* XXX */
    115 	if (dses->__dses_npendreqs)
    116 		panic("dmover_session_destroy");
    117 
    118 	dmover_backend_release(dses);
    119 	pool_put(&dmover_session_pool, dses);
    120 }
    121