1/**************************************************************************
2 *
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
18 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
19 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20 * USE OR OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * The above copyright notice and this permission notice (including the
23 * next paragraph) shall be included in all copies or substantial portions
24 * of the Software.
25 */
26
27/*
28 * List macros heavily inspired by the Linux kernel
29 * list handling. No list looping yet.
30 */
31
32#include <stddef.h>
33
34typedef struct _drmMMListHead
35{
36    struct _drmMMListHead *prev;
37    struct _drmMMListHead *next;
38} drmMMListHead;
39
40#define DRMINITLISTHEAD(__item)		       \
41  do{					       \
42    (__item)->prev = (__item);		       \
43    (__item)->next = (__item);		       \
44  } while (0)
45
46#define DRMLISTADD(__item, __list)		\
47  do {						\
48    (__item)->prev = (__list);			\
49    (__item)->next = (__list)->next;		\
50    (__list)->next->prev = (__item);		\
51    (__list)->next = (__item);			\
52  } while (0)
53
54#define DRMLISTADDTAIL(__item, __list)		\
55  do {						\
56    (__item)->next = (__list);			\
57    (__item)->prev = (__list)->prev;		\
58    (__list)->prev->next = (__item);		\
59    (__list)->prev = (__item);			\
60  } while(0)
61
62#define DRMLISTDEL(__item)			\
63  do {						\
64    (__item)->prev->next = (__item)->next;	\
65    (__item)->next->prev = (__item)->prev;	\
66  } while(0)
67
68#define DRMLISTDELINIT(__item)			\
69  do {						\
70    (__item)->prev->next = (__item)->next;	\
71    (__item)->next->prev = (__item)->prev;	\
72    (__item)->next = (__item);			\
73    (__item)->prev = (__item);			\
74  } while(0)
75
76#define DRMLISTENTRY(__type, __item, __field)   \
77    ((__type *)(((char *) (__item)) - offsetof(__type, __field)))
78
79#define DRMLISTEMPTY(__item) ((__item)->next == (__item))
80
81#define DRMLISTSINGLE(__list) \
82	(!DRMLISTEMPTY(__list) && ((__list)->next == (__list)->prev))
83
84#define DRMLISTFOREACH(__item, __list)					\
85	for ((__item) = (__list)->next;					\
86	     (__item) != (__list); (__item) = (__item)->next)
87
88#define DRMLISTFOREACHSAFE(__item, __temp, __list)			\
89	for ((__item) = (__list)->next, (__temp) = (__item)->next;	\
90	     (__item) != (__list);					\
91	     (__item) = (__temp), (__temp) = (__item)->next)
92
93#define DRMLISTFOREACHSAFEREVERSE(__item, __temp, __list)		\
94	for ((__item) = (__list)->prev, (__temp) = (__item)->prev;	\
95	     (__item) != (__list);					\
96	     (__item) = (__temp), (__temp) = (__item)->prev)
97
98#define DRMLISTFOREACHENTRY(__item, __list, __head)                            \
99	for ((__item) = DRMLISTENTRY(typeof(*__item), (__list)->next, __head); \
100	     &(__item)->__head != (__list);                                    \
101	     (__item) = DRMLISTENTRY(typeof(*__item),                          \
102				     (__item)->__head.next, __head))
103
104#define DRMLISTFOREACHENTRYSAFE(__item, __temp, __list, __head)                \
105	for ((__item) = DRMLISTENTRY(typeof(*__item), (__list)->next, __head), \
106	     (__temp) = DRMLISTENTRY(typeof(*__item),                          \
107				     (__item)->__head.next, __head);           \
108	     &(__item)->__head != (__list);                                    \
109	     (__item) = (__temp),                                              \
110	     (__temp) = DRMLISTENTRY(typeof(*__item),                          \
111				     (__temp)->__head.next, __head))
112
113#define DRMLISTJOIN(__list, __join) if (!DRMLISTEMPTY(__list)) {	\
114	(__list)->next->prev = (__join);				\
115	(__list)->prev->next = (__join)->next;				\
116	(__join)->next->prev = (__list)->prev;				\
117	(__join)->next = (__list)->next;				\
118}
119