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dmover_session.c revision 1.1 
      1 /*	$NetBSD: dmover_session.c,v 1.1 2002/08/02 00:30:39 thorpej 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 1.1 2002/08/02 00:30:39 thorpej Exp $");
     44 
     45 #include <sys/param.h>
     46 #include <sys/lock.h>
     47 #include <sys/pool.h>
     48 #include <sys/systm.h>
     49 #include <sys/malloc.h>
     50 
     51 #include <dev/dmover/dmovervar.h>
     52 
     53 struct pool dmover_session_pool;
     54 
     55 static int initialized;
     56 static struct simplelock initialized_slock = SIMPLELOCK_INITIALIZER;
     57 
     58 void
     59 dmover_session_initialize(void)
     60 {
     61 
     62 	simple_lock(&initialized_slock);
     63 	if (__predict_true(initialized == 0)) {
     64 		pool_init(&dmover_session_pool, sizeof(struct dmover_session),
     65 		    0, 0, 0, "dmses", &pool_allocator_nointr);
     66 		initialized = 1;
     67 	}
     68 	simple_unlock(&initialized_slock);
     69 }
     70 
     71 /*
     72  * dmover_session_create:	[client interface function]
     73  *
     74  *	Create a dmover session.
     75  */
     76 int
     77 dmover_session_create(const char *type, struct dmover_session **dsesp)
     78 {
     79 	struct dmover_session *dses;
     80 	int error;
     81 
     82 	if (__predict_false(initialized == 0)) {
     83 		simple_lock(&initialized_slock);
     84 		error = initialized ? 0 : ENXIO;
     85 		simple_unlock(&initialized_slock);
     86 
     87 		if (error)
     88 			return (error);
     89 	}
     90 
     91 	dses = pool_get(&dmover_session_pool, PR_NOWAIT);
     92 	if (__predict_false(dses == NULL))
     93 		return (ENOMEM);
     94 
     95 	/* Allocate a back-end to the session. */
     96 	error = dmover_backend_alloc(dses, type);
     97 	if (__predict_false(error)) {
     98 		pool_put(&dmover_session_pool, dses);
     99 		return (error);
    100 	}
    101 
    102 	TAILQ_INIT(&dses->__dses_pendreqs);
    103 	dses->__dses_npendreqs = 0;
    104 
    105 	*dsesp = dses;
    106 	return (0);
    107 }
    108 
    109 /*
    110  * dmover_session_destroy:	[client interface function]
    111  *
    112  *	Tear down a dmover session.
    113  */
    114 void
    115 dmover_session_destroy(struct dmover_session *dses)
    116 {
    117 
    118 #ifdef DIAGNOSTIC
    119 	if (__predict_false(initialized == 0)) {
    120 		int croak;
    121 
    122 		simple_lock(&initialized_slock);
    123 		croak = (initialized == 0);
    124 		simple_unlock(&initialized_slock);
    125 
    126 		if (croak)
    127 			panic("dmover_session_destroy: not initialized");
    128 	}
    129 #endif
    130 
    131 	/* XXX */
    132 	if (dses->__dses_npendreqs)
    133 		panic("dmover_session_destroy");
    134 
    135 	dmover_backend_release(dses);
    136 	pool_put(&dmover_session_pool, dses);
    137 }
    138