1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * Embedded Linked Lists 30 * 31 * Simple doubly-linked list implementation. This implementation assumes that 32 * each list element contains an embedded ipmi_list_t (previous and next 33 * pointers), which is typically the first member of the element struct. 34 * An additional ipmi_list_t is used to store the head (l_next) and tail 35 * (l_prev) pointers. The current head and tail list elements have their 36 * previous and next pointers set to NULL, respectively. 37 */ 38 39 #include <assert.h> 40 #include <ipmi_impl.h> 41 42 void 43 ipmi_list_append(ipmi_list_t *lp, void *new) 44 { 45 ipmi_list_t *p = lp->l_prev; /* p = tail list element */ 46 ipmi_list_t *q = new; /* q = new list element */ 47 48 lp->l_prev = q; 49 q->l_prev = p; 50 q->l_next = NULL; 51 52 if (p != NULL) { 53 assert(p->l_next == NULL); 54 p->l_next = q; 55 } else { 56 assert(lp->l_next == NULL); 57 lp->l_next = q; 58 } 59 } 60 61 void 62 ipmi_list_prepend(ipmi_list_t *lp, void *new) 63 { 64 ipmi_list_t *p = new; /* p = new list element */ 65 ipmi_list_t *q = lp->l_next; /* q = head list element */ 66 67 lp->l_next = p; 68 p->l_prev = NULL; 69 p->l_next = q; 70 71 if (q != NULL) { 72 assert(q->l_prev == NULL); 73 q->l_prev = p; 74 } else { 75 assert(lp->l_prev == NULL); 76 lp->l_prev = p; 77 } 78 } 79 80 void 81 ipmi_list_insert_before(ipmi_list_t *lp, void *before_me, void *new) 82 { 83 ipmi_list_t *p = before_me; 84 ipmi_list_t *q = new; 85 86 if (p == NULL || p->l_prev == NULL) { 87 ipmi_list_prepend(lp, new); 88 return; 89 } 90 91 q->l_prev = p->l_prev; 92 q->l_next = p; 93 p->l_prev = q; 94 q->l_prev->l_next = q; 95 } 96 97 void 98 ipmi_list_insert_after(ipmi_list_t *lp, void *after_me, void *new) 99 { 100 ipmi_list_t *p = after_me; 101 ipmi_list_t *q = new; 102 103 if (p == NULL || p->l_next == NULL) { 104 ipmi_list_append(lp, new); 105 return; 106 } 107 108 q->l_next = p->l_next; 109 q->l_prev = p; 110 p->l_next = q; 111 q->l_next->l_prev = q; 112 } 113 114 void 115 ipmi_list_delete(ipmi_list_t *lp, void *existing) 116 { 117 ipmi_list_t *p = existing; 118 119 if (p->l_prev != NULL) 120 p->l_prev->l_next = p->l_next; 121 else 122 lp->l_next = p->l_next; 123 124 if (p->l_next != NULL) 125 p->l_next->l_prev = p->l_prev; 126 else 127 lp->l_prev = p->l_prev; 128 } 129