1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2018 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29 #ifndef _LINUXKPI_LINUX_RADIX_TREE_H_
30 #define _LINUXKPI_LINUX_RADIX_TREE_H_
31
32 #include <linux/rcupdate.h>
33 #include <linux/types.h>
34
35 #define RADIX_TREE_MAP_SHIFT 6
36 #define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT)
37 #define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE - 1UL)
38 #define RADIX_TREE_MAX_HEIGHT \
39 howmany(sizeof(long) * NBBY, RADIX_TREE_MAP_SHIFT)
40
41 #define RADIX_TREE_MAX_TAGS 3
42 #define RADIX_TREE_TAG_LONGS RADIX_TREE_MAP_SIZE
43
44 #define RADIX_TREE_ENTRY_MASK 3UL
45 #define RADIX_TREE_EXCEPTIONAL_ENTRY 2UL
46 #define RADIX_TREE_EXCEPTIONAL_SHIFT 2
47
48 #define RADIX_TREE_ITER_TAG_MASK 0x0f
49 #define RADIX_TREE_ITER_TAGGED 0x10
50
51 struct radix_tree_node {
52 void *slots[RADIX_TREE_MAP_SIZE];
53 unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
54 int count;
55 };
56
57 struct radix_tree_root {
58 struct radix_tree_node *rnode;
59 gfp_t gfp_mask;
60 int height;
61 /* Linux stores root tags inside `gfp_mask`. */
62 unsigned long tags[RADIX_TREE_MAX_TAGS];
63 };
64
65 struct radix_tree_iter {
66 unsigned long index;
67 };
68
69 #define RADIX_TREE_INIT(mask) \
70 { .rnode = NULL, .gfp_mask = mask, .height = 0 };
71 #define INIT_RADIX_TREE(root, mask) \
72 { (root)->rnode = NULL; (root)->gfp_mask = mask; (root)->height = 0; }
73 #define RADIX_TREE(name, mask) \
74 struct radix_tree_root name = RADIX_TREE_INIT(mask)
75
76 #define radix_tree_for_each_slot(slot, root, iter, start) \
77 for ((iter)->index = (start); \
78 radix_tree_iter_find(root, iter, &(slot), 0); \
79 (iter)->index++)
80
81 #define radix_tree_for_each_slot_tagged(slot, root, iter, start, tag) \
82 for ((iter)->index = (start); \
83 radix_tree_iter_find(root, iter, &(slot), \
84 RADIX_TREE_ITER_TAGGED | tag); \
85 (iter)->index++)
86
87 static inline void *
radix_tree_deref_slot(void ** slot)88 radix_tree_deref_slot(void **slot)
89 {
90 return (*slot);
91 }
92
93 static inline int
radix_tree_exception(void * arg)94 radix_tree_exception(void *arg)
95 {
96 return ((uintptr_t)arg & RADIX_TREE_ENTRY_MASK);
97 }
98
99 void *radix_tree_lookup(const struct radix_tree_root *, unsigned long);
100 void *radix_tree_delete(struct radix_tree_root *, unsigned long);
101 int radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
102 int radix_tree_store(struct radix_tree_root *, unsigned long, void **);
103 bool radix_tree_iter_find(const struct radix_tree_root *, struct radix_tree_iter *, void ***, int);
104 void radix_tree_iter_delete(struct radix_tree_root *, struct radix_tree_iter *, void **);
105 void *radix_tree_tag_set(struct radix_tree_root *root, unsigned long index, unsigned int tag);
106 void *radix_tree_tag_clear(struct radix_tree_root *root, unsigned long index, unsigned int tag);
107 int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag);
108 unsigned int radix_tree_gang_lookup(const struct radix_tree_root *root, void **results, unsigned long first_index, unsigned int max_items);
109 unsigned int radix_tree_gang_lookup_tag(const struct radix_tree_root *root, void **results, unsigned long first_index, unsigned int max_items, unsigned int tag);
110
111 #endif /* _LINUXKPI_LINUX_RADIX_TREE_H_ */
112