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 /* 27 * Embedded Linked Lists 28 * 29 * Simple doubly-linked list implementation. This implementation assumes that 30 * each list element contains an embedded ipmi_list_t (previous and next 31 * pointers), which is typically the first member of the element struct. 32 * An additional ipmi_list_t is used to store the head (l_next) and tail 33 * (l_prev) pointers. The current head and tail list elements have their 34 * previous and next pointers set to NULL, respectively. 35 */ 36 37 #include <assert.h> 38 #include <ipmi_impl.h> 39 40 void 41 ipmi_list_append(ipmi_list_t *lp, void *new) 42 { 43 ipmi_list_t *p = lp->l_prev; /* p = tail list element */ 44 ipmi_list_t *q = new; /* q = new list element */ 45 46 lp->l_prev = q; 47 q->l_prev = p; 48 q->l_next = NULL; 49 50 if (p != NULL) { 51 assert(p->l_next == NULL); 52 p->l_next = q; 53 } else { 54 assert(lp->l_next == NULL); 55 lp->l_next = q; 56 } 57 } 58 59 void 60 ipmi_list_prepend(ipmi_list_t *lp, void *new) 61 { 62 ipmi_list_t *p = new; /* p = new list element */ 63 ipmi_list_t *q = lp->l_next; /* q = head list element */ 64 65 lp->l_next = p; 66 p->l_prev = NULL; 67 p->l_next = q; 68 69 if (q != NULL) { 70 assert(q->l_prev == NULL); 71 q->l_prev = p; 72 } else { 73 assert(lp->l_prev == NULL); 74 lp->l_prev = p; 75 } 76 } 77 78 void 79 ipmi_list_insert_before(ipmi_list_t *lp, void *before_me, void *new) 80 { 81 ipmi_list_t *p = before_me; 82 ipmi_list_t *q = new; 83 84 if (p == NULL || p->l_prev == NULL) { 85 ipmi_list_prepend(lp, new); 86 return; 87 } 88 89 q->l_prev = p->l_prev; 90 q->l_next = p; 91 p->l_prev = q; 92 q->l_prev->l_next = q; 93 } 94 95 void 96 ipmi_list_insert_after(ipmi_list_t *lp, void *after_me, void *new) 97 { 98 ipmi_list_t *p = after_me; 99 ipmi_list_t *q = new; 100 101 if (p == NULL || p->l_next == NULL) { 102 ipmi_list_append(lp, new); 103 return; 104 } 105 106 q->l_next = p->l_next; 107 q->l_prev = p; 108 p->l_next = q; 109 q->l_next->l_prev = q; 110 } 111 112 void 113 ipmi_list_delete(ipmi_list_t *lp, void *existing) 114 { 115 ipmi_list_t *p = existing; 116 117 if (p->l_prev != NULL) 118 p->l_prev->l_next = p->l_next; 119 else 120 lp->l_next = p->l_next; 121 122 if (p->l_next != NULL) 123 p->l_next->l_prev = p->l_prev; 124 else 125 lp->l_prev = p->l_prev; 126 } 127