1 /*-
2 * Copyright (c) 2002-2007 Neterion, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29 #ifndef XGE_LIST_H
30 #define XGE_LIST_H
31
32 #include <dev/nxge/include/xge-debug.h>
33
34 __EXTERN_BEGIN_DECLS
35
36 /**
37 * struct xge_list_t - List item.
38 * @prev: Previous list item.
39 * @next: Next list item.
40 *
41 * Item of a bi-directional linked list.
42 */
43 typedef struct xge_list_t {
44 struct xge_list_t* prev;
45 struct xge_list_t* next;
46 } xge_list_t;
47
48 /**
49 * xge_list_init - Initialize linked list.
50 * header: first element of the list (head)
51 *
52 * Initialize linked list.
53 * See also: xge_list_t{}.
54 */
55 static inline void xge_list_init (xge_list_t *header)
56 {
57 header->next = header;
58 header->prev = header;
59 }
60
61 /**
62 * xge_list_is_empty - Is the list empty?
63 * header: first element of the list (head)
64 *
65 * Determine whether the bi-directional list is empty. Return '1' in
66 * case of 'empty'.
67 * See also: xge_list_t{}.
68 */
69 static inline int xge_list_is_empty(xge_list_t *header)
70 {
71 xge_assert(header != NULL);
72
73 return header->next == header;
74 }
75
76 /**
77 * xge_list_first_get - Return the first item from the linked list.
78 * header: first element of the list (head)
79 *
80 * Returns the next item from the header.
81 * Returns NULL if the next item is header itself
82 * See also: xge_list_remove(), xge_list_insert(), xge_list_t{}.
83 */
84 static inline xge_list_t *xge_list_first_get(xge_list_t *header)
85 {
86 xge_assert(header != NULL);
87 xge_assert(header->next != NULL);
88 xge_assert(header->prev != NULL);
89
90 if(header->next == header)
91 return NULL;
92 else
93 return header->next;
94 }
95
96 /**
97 * xge_list_remove - Remove the specified item from the linked list.
98 * item: element of the list
99 *
100 * Remove item from a list.
101 * See also: xge_list_insert(), xge_list_t{}.
102 */
103 static inline void xge_list_remove(xge_list_t *item)
104 {
105 xge_assert(item != NULL);
106 xge_assert(item->next != NULL);
107 xge_assert(item->prev != NULL);
108
109 item->next->prev = item->prev;
110 item->prev->next = item->next;
111 #ifdef XGE_DEBUG_ASSERT
112 item->next = item->prev = NULL;
113 #endif
114 }
115
116 /**
117 * xge_list_insert - Insert a new item after the specified item.
118 * new_item: new element of the list
119 * prev_item: element of the list after which the new element is
120 * inserted
121 *
122 * Insert new item (new_item) after given item (prev_item).
123 * See also: xge_list_remove(), xge_list_insert_before(), xge_list_t{}.
124 */
125 static inline void xge_list_insert (xge_list_t *new_item,
126 xge_list_t *prev_item)
127 {
128 xge_assert(new_item != NULL);
129 xge_assert(prev_item != NULL);
130 xge_assert(prev_item->next != NULL);
131
132 new_item->next = prev_item->next;
133 new_item->prev = prev_item;
134 prev_item->next->prev = new_item;
135 prev_item->next = new_item;
136 }
137
138 /**
139 * xge_list_insert_before - Insert a new item before the specified item.
140 * new_item: new element of the list
141 * next_item: element of the list after which the new element is inserted
142 *
143 * Insert new item (new_item) before given item (next_item).
144 */
145 static inline void xge_list_insert_before (xge_list_t *new_item,
146 xge_list_t *next_item)
147 {
148 xge_assert(new_item != NULL);
149 xge_assert(next_item != NULL);
150 xge_assert(next_item->next != NULL);
151
152 new_item->next = next_item;
153 new_item->prev = next_item->prev;
154 next_item->prev->next = new_item;
155 next_item->prev = new_item;
156 }
157
158 #define xge_list_for_each(_p, _h) \
159 for (_p = (_h)->next, xge_os_prefetch(_p->next); _p != (_h); \
160 _p = _p->next, xge_os_prefetch(_p->next))
161
162 #define xge_list_for_each_safe(_p, _n, _h) \
163 for (_p = (_h)->next, _n = _p->next; _p != (_h); \
164 _p = _n, _n = _p->next)
165
166 #ifdef __GNUC__
167 /**
168 * xge_container_of - Given a member, return the containing structure.
169 * @ptr: the pointer to the member.
170 * @type: the type of the container struct this is embedded in.
171 * @member: the name of the member within the struct.
172 *
173 * Cast a member of a structure out to the containing structure.
174 */
175 #define xge_container_of(ptr, type, member) ({ \
176 __typeof( ((type *)0)->member ) *__mptr = (ptr); \
177 (type *)(void *)( (char *)__mptr - ((size_t) &((type *)0)->member) );})
178 #else
179 /* type unsafe version */
180 #define xge_container_of(ptr, type, member) \
181 ((type*)(void*)((char*)(ptr) - ((size_t) &((type *)0)->member)))
182 #endif
183
184 /**
185 * xge_offsetof - Offset of the member in the containing structure.
186 * @t: struct name.
187 * @m: the name of the member within the struct.
188 *
189 * Return the offset of the member @m in the structure @t.
190 */
191 #define xge_offsetof(t, m) ((size_t) (&((t *)0)->m))
192
193 __EXTERN_END_DECLS
194
195 #endif /* XGE_LIST_H */
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