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1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef BTRFS_MISC_H
4#define BTRFS_MISC_H
5
6#include <linux/sched.h>
7#include <linux/wait.h>
8#include <asm/div64.h>
9
10#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
11
12static inline void cond_wake_up(struct wait_queue_head *wq)
13{
14 /*
15 * This implies a full smp_mb barrier, see comments for
16 * waitqueue_active why.
17 */
18 if (wq_has_sleeper(wq))
19 wake_up(wq);
20}
21
22static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
23{
24 /*
25 * Special case for conditional wakeup where the barrier required for
26 * waitqueue_active is implied by some of the preceding code. Eg. one
27 * of such atomic operations (atomic_dec_and_return, ...), or a
28 * unlock/lock sequence, etc.
29 */
30 if (waitqueue_active(wq))
31 wake_up(wq);
32}
33
34static inline u64 div_factor(u64 num, int factor)
35{
36 if (factor == 10)
37 return num;
38 num *= factor;
39 return div_u64(num, 10);
40}
41
42static inline u64 div_factor_fine(u64 num, int factor)
43{
44 if (factor == 100)
45 return num;
46 num *= factor;
47 return div_u64(num, 100);
48}
49
50#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef BTRFS_MISC_H
4#define BTRFS_MISC_H
5
6#include <linux/types.h>
7#include <linux/bitmap.h>
8#include <linux/sched.h>
9#include <linux/wait.h>
10#include <linux/math64.h>
11#include <linux/rbtree.h>
12
13/*
14 * Enumerate bits using enum autoincrement. Define the @name as the n-th bit.
15 */
16#define ENUM_BIT(name) \
17 __ ## name ## _BIT, \
18 name = (1U << __ ## name ## _BIT), \
19 __ ## name ## _SEQ = __ ## name ## _BIT
20
21static inline void cond_wake_up(struct wait_queue_head *wq)
22{
23 /*
24 * This implies a full smp_mb barrier, see comments for
25 * waitqueue_active why.
26 */
27 if (wq_has_sleeper(wq))
28 wake_up(wq);
29}
30
31static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
32{
33 /*
34 * Special case for conditional wakeup where the barrier required for
35 * waitqueue_active is implied by some of the preceding code. Eg. one
36 * of such atomic operations (atomic_dec_and_return, ...), or a
37 * unlock/lock sequence, etc.
38 */
39 if (waitqueue_active(wq))
40 wake_up(wq);
41}
42
43static inline u64 mult_perc(u64 num, u32 percent)
44{
45 return div_u64(num * percent, 100);
46}
47/* Copy of is_power_of_two that is 64bit safe */
48static inline bool is_power_of_two_u64(u64 n)
49{
50 return n != 0 && (n & (n - 1)) == 0;
51}
52
53static inline bool has_single_bit_set(u64 n)
54{
55 return is_power_of_two_u64(n);
56}
57
58/*
59 * Simple bytenr based rb_tree relate structures
60 *
61 * Any structure wants to use bytenr as single search index should have their
62 * structure start with these members.
63 */
64struct rb_simple_node {
65 struct rb_node rb_node;
66 u64 bytenr;
67};
68
69static inline struct rb_node *rb_simple_search(struct rb_root *root, u64 bytenr)
70{
71 struct rb_node *node = root->rb_node;
72 struct rb_simple_node *entry;
73
74 while (node) {
75 entry = rb_entry(node, struct rb_simple_node, rb_node);
76
77 if (bytenr < entry->bytenr)
78 node = node->rb_left;
79 else if (bytenr > entry->bytenr)
80 node = node->rb_right;
81 else
82 return node;
83 }
84 return NULL;
85}
86
87/*
88 * Search @root from an entry that starts or comes after @bytenr.
89 *
90 * @root: the root to search.
91 * @bytenr: bytenr to search from.
92 *
93 * Return the rb_node that start at or after @bytenr. If there is no entry at
94 * or after @bytner return NULL.
95 */
96static inline struct rb_node *rb_simple_search_first(struct rb_root *root,
97 u64 bytenr)
98{
99 struct rb_node *node = root->rb_node, *ret = NULL;
100 struct rb_simple_node *entry, *ret_entry = NULL;
101
102 while (node) {
103 entry = rb_entry(node, struct rb_simple_node, rb_node);
104
105 if (bytenr < entry->bytenr) {
106 if (!ret || entry->bytenr < ret_entry->bytenr) {
107 ret = node;
108 ret_entry = entry;
109 }
110
111 node = node->rb_left;
112 } else if (bytenr > entry->bytenr) {
113 node = node->rb_right;
114 } else {
115 return node;
116 }
117 }
118
119 return ret;
120}
121
122static inline struct rb_node *rb_simple_insert(struct rb_root *root, u64 bytenr,
123 struct rb_node *node)
124{
125 struct rb_node **p = &root->rb_node;
126 struct rb_node *parent = NULL;
127 struct rb_simple_node *entry;
128
129 while (*p) {
130 parent = *p;
131 entry = rb_entry(parent, struct rb_simple_node, rb_node);
132
133 if (bytenr < entry->bytenr)
134 p = &(*p)->rb_left;
135 else if (bytenr > entry->bytenr)
136 p = &(*p)->rb_right;
137 else
138 return parent;
139 }
140
141 rb_link_node(node, parent, p);
142 rb_insert_color(node, root);
143 return NULL;
144}
145
146static inline bool bitmap_test_range_all_set(const unsigned long *addr,
147 unsigned long start,
148 unsigned long nbits)
149{
150 unsigned long found_zero;
151
152 found_zero = find_next_zero_bit(addr, start + nbits, start);
153 return (found_zero == start + nbits);
154}
155
156static inline bool bitmap_test_range_all_zero(const unsigned long *addr,
157 unsigned long start,
158 unsigned long nbits)
159{
160 unsigned long found_set;
161
162 found_set = find_next_bit(addr, start + nbits, start);
163 return (found_set == start + nbits);
164}
165
166#endif