1 /* $NetBSD: dmover_session.c,v 1.5 2008/01/04 21:17:52 ad 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 1.5 2008/01/04 21:17:52 ad Exp $"); 44 45 #include <sys/param.h> 46 #include <sys/simplelock.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, IPL_NONE); 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