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Linux kernel mirror (for testing)
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linux
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/mm.h>
11#include <linux/pagemap.h>
12#include <linux/math64.h>
13#include <linux/rbtree.h>
14
15/*
16 * Enumerate bits using enum autoincrement. Define the @name as the n-th bit.
17 */
18#define ENUM_BIT(name) \
19 __ ## name ## _BIT, \
20 name = (1U << __ ## name ## _BIT), \
21 __ ## name ## _SEQ = __ ## name ## _BIT
22
23static inline void cond_wake_up(struct wait_queue_head *wq)
24{
25 /*
26 * This implies a full smp_mb barrier, see comments for
27 * waitqueue_active why.
28 */
29 if (wq_has_sleeper(wq))
30 wake_up(wq);
31}
32
33static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
34{
35 /*
36 * Special case for conditional wakeup where the barrier required for
37 * waitqueue_active is implied by some of the preceding code. Eg. one
38 * of such atomic operations (atomic_dec_and_return, ...), or a
39 * unlock/lock sequence, etc.
40 */
41 if (waitqueue_active(wq))
42 wake_up(wq);
43}
44
45static inline u64 mult_perc(u64 num, u32 percent)
46{
47 return div_u64(num * percent, 100);
48}
49/* Copy of is_power_of_two that is 64bit safe */
50static inline bool is_power_of_two_u64(u64 n)
51{
52 return n != 0 && (n & (n - 1)) == 0;
53}
54
55static inline bool has_single_bit_set(u64 n)
56{
57 return is_power_of_two_u64(n);
58}
59
60/*
61 * Simple bytenr based rb_tree relate structures
62 *
63 * Any structure wants to use bytenr as single search index should have their
64 * structure start with these members.
65 */
66struct rb_simple_node {
67 struct rb_node rb_node;
68 u64 bytenr;
69};
70
71static inline struct rb_node *rb_simple_search(const struct rb_root *root, u64 bytenr)
72{
73 struct rb_node *node = root->rb_node;
74 struct rb_simple_node *entry;
75
76 while (node) {
77 entry = rb_entry(node, struct rb_simple_node, rb_node);
78
79 if (bytenr < entry->bytenr)
80 node = node->rb_left;
81 else if (bytenr > entry->bytenr)
82 node = node->rb_right;
83 else
84 return node;
85 }
86 return NULL;
87}
88
89/*
90 * Search @root from an entry that starts or comes after @bytenr.
91 *
92 * @root: the root to search.
93 * @bytenr: bytenr to search from.
94 *
95 * Return the rb_node that start at or after @bytenr. If there is no entry at
96 * or after @bytner return NULL.
97 */
98static inline struct rb_node *rb_simple_search_first(const struct rb_root *root,
99 u64 bytenr)
100{
101 struct rb_node *node = root->rb_node, *ret = NULL;
102 struct rb_simple_node *entry, *ret_entry = NULL;
103
104 while (node) {
105 entry = rb_entry(node, struct rb_simple_node, rb_node);
106
107 if (bytenr < entry->bytenr) {
108 if (!ret || entry->bytenr < ret_entry->bytenr) {
109 ret = node;
110 ret_entry = entry;
111 }
112
113 node = node->rb_left;
114 } else if (bytenr > entry->bytenr) {
115 node = node->rb_right;
116 } else {
117 return node;
118 }
119 }
120
121 return ret;
122}
123
124static int rb_simple_node_bytenr_cmp(struct rb_node *new, const struct rb_node *existing)
125{
126 struct rb_simple_node *new_entry = rb_entry(new, struct rb_simple_node, rb_node);
127 struct rb_simple_node *existing_entry = rb_entry(existing, struct rb_simple_node, rb_node);
128
129 if (new_entry->bytenr < existing_entry->bytenr)
130 return -1;
131 else if (new_entry->bytenr > existing_entry->bytenr)
132 return 1;
133
134 return 0;
135}
136
137static inline struct rb_node *rb_simple_insert(struct rb_root *root,
138 struct rb_simple_node *simple_node)
139{
140 return rb_find_add(&simple_node->rb_node, root, rb_simple_node_bytenr_cmp);
141}
142
143static inline bool bitmap_test_range_all_set(const unsigned long *addr,
144 unsigned long start,
145 unsigned long nbits)
146{
147 unsigned long found_zero;
148
149 found_zero = find_next_zero_bit(addr, start + nbits, start);
150 return (found_zero == start + nbits);
151}
152
153static inline bool bitmap_test_range_all_zero(const unsigned long *addr,
154 unsigned long start,
155 unsigned long nbits)
156{
157 unsigned long found_set;
158
159 found_set = find_next_bit(addr, start + nbits, start);
160 return (found_set == start + nbits);
161}
162
163static inline u64 folio_end(struct folio *folio)
164{
165 return folio_pos(folio) + folio_size(folio);
166}
167
168#endif