Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6] / include / linux / prio_tree.h
1 #ifndef _LINUX_PRIO_TREE_H
2 #define _LINUX_PRIO_TREE_H
3
4 /*
5  * K&R 2nd ed. A8.3 somewhat obliquely hints that initial sequences of struct
6  * fields with identical types should end up at the same location. We'll use
7  * this until we can scrap struct raw_prio_tree_node.
8  *
9  * Note: all this could be done more elegantly by using unnamed union/struct
10  * fields. However, gcc 2.95.3 and apparently also gcc 3.0.4 don't support this
11  * language extension.
12  */
13
14 struct raw_prio_tree_node {
15         struct prio_tree_node   *left;
16         struct prio_tree_node   *right;
17         struct prio_tree_node   *parent;
18 };
19
20 struct prio_tree_node {
21         struct prio_tree_node   *left;
22         struct prio_tree_node   *right;
23         struct prio_tree_node   *parent;
24         unsigned long           start;
25         unsigned long           last;   /* last location _in_ interval */
26 };
27
28 struct prio_tree_root {
29         struct prio_tree_node   *prio_tree_node;
30         unsigned short          index_bits;
31         unsigned short          raw;
32                 /*
33                  * 0: nodes are of type struct prio_tree_node
34                  * 1: nodes are of type raw_prio_tree_node
35                  */
36 };
37
38 struct prio_tree_iter {
39         struct prio_tree_node   *cur;
40         unsigned long           mask;
41         unsigned long           value;
42         int                     size_level;
43
44         struct prio_tree_root   *root;
45         pgoff_t                 r_index;
46         pgoff_t                 h_index;
47 };
48
49 static inline void prio_tree_iter_init(struct prio_tree_iter *iter,
50                 struct prio_tree_root *root, pgoff_t r_index, pgoff_t h_index)
51 {
52         iter->root = root;
53         iter->r_index = r_index;
54         iter->h_index = h_index;
55         iter->cur = NULL;
56 }
57
58 #define __INIT_PRIO_TREE_ROOT(ptr, _raw)        \
59 do {                                    \
60         (ptr)->prio_tree_node = NULL;   \
61         (ptr)->index_bits = 1;          \
62         (ptr)->raw = (_raw);            \
63 } while (0)
64
65 #define INIT_PRIO_TREE_ROOT(ptr)        __INIT_PRIO_TREE_ROOT(ptr, 0)
66 #define INIT_RAW_PRIO_TREE_ROOT(ptr)    __INIT_PRIO_TREE_ROOT(ptr, 1)
67
68 #define INIT_PRIO_TREE_NODE(ptr)                                \
69 do {                                                            \
70         (ptr)->left = (ptr)->right = (ptr)->parent = (ptr);     \
71 } while (0)
72
73 #define INIT_PRIO_TREE_ITER(ptr)        \
74 do {                                    \
75         (ptr)->cur = NULL;              \
76         (ptr)->mask = 0UL;              \
77         (ptr)->value = 0UL;             \
78         (ptr)->size_level = 0;          \
79 } while (0)
80
81 #define prio_tree_entry(ptr, type, member) \
82        ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
83
84 static inline int prio_tree_empty(const struct prio_tree_root *root)
85 {
86         return root->prio_tree_node == NULL;
87 }
88
89 static inline int prio_tree_root(const struct prio_tree_node *node)
90 {
91         return node->parent == node;
92 }
93
94 static inline int prio_tree_left_empty(const struct prio_tree_node *node)
95 {
96         return node->left == node;
97 }
98
99 static inline int prio_tree_right_empty(const struct prio_tree_node *node)
100 {
101         return node->right == node;
102 }
103
104
105 struct prio_tree_node *prio_tree_replace(struct prio_tree_root *root,
106                 struct prio_tree_node *old, struct prio_tree_node *node);
107 struct prio_tree_node *prio_tree_insert(struct prio_tree_root *root,
108                 struct prio_tree_node *node);
109 void prio_tree_remove(struct prio_tree_root *root, struct prio_tree_node *node);
110 struct prio_tree_node *prio_tree_next(struct prio_tree_iter *iter);
111
112 #define raw_prio_tree_replace(root, old, node) \
113         prio_tree_replace(root, (struct prio_tree_node *) (old), \
114             (struct prio_tree_node *) (node))
115 #define raw_prio_tree_insert(root, node) \
116         prio_tree_insert(root, (struct prio_tree_node *) (node))
117 #define raw_prio_tree_remove(root, node) \
118         prio_tree_remove(root, (struct prio_tree_node *) (node))
119
120 #endif /* _LINUX_PRIO_TREE_H */