1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _TOOLS_LINUX_FIND_H_
3 #define _TOOLS_LINUX_FIND_H_
4
5 #ifndef _TOOLS_LINUX_BITMAP_H
6 #error tools: only <linux/bitmap.h> can be included directly
7 #endif
8
9 #include <linux/bitops.h>
10
11 unsigned long _find_next_bit(const unsigned long *addr1, unsigned long nbits,
12 unsigned long start);
13 unsigned long _find_next_and_bit(const unsigned long *addr1, const unsigned long *addr2,
14 unsigned long nbits, unsigned long start);
15 unsigned long _find_next_zero_bit(const unsigned long *addr, unsigned long nbits,
16 unsigned long start);
17 extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size);
18 extern unsigned long _find_first_and_bit(const unsigned long *addr1,
19 const unsigned long *addr2, unsigned long size);
20 extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size);
21
22 #ifndef find_next_bit
23 /**
24 * find_next_bit - find the next set bit in a memory region
25 * @addr: The address to base the search on
26 * @size: The bitmap size in bits
27 * @offset: The bitnumber to start searching at
28 *
29 * Returns the bit number for the next set bit
30 * If no bits are set, returns @size.
31 */
32 static inline
33 unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
34 unsigned long offset)
35 {
36 if (small_const_nbits(size)) {
37 unsigned long val;
38
39 if (unlikely(offset >= size))
40 return size;
41
42 val = *addr & GENMASK(size - 1, offset);
43 return val ? __ffs(val) : size;
44 }
45
46 return _find_next_bit(addr, size, offset);
47 }
48 #endif
49
50 #ifndef find_next_and_bit
51 /**
52 * find_next_and_bit - find the next set bit in both memory regions
53 * @addr1: The first address to base the search on
54 * @addr2: The second address to base the search on
55 * @size: The bitmap size in bits
56 * @offset: The bitnumber to start searching at
57 *
58 * Returns the bit number for the next set bit
59 * If no bits are set, returns @size.
60 */
61 static inline
62 unsigned long find_next_and_bit(const unsigned long *addr1,
63 const unsigned long *addr2, unsigned long size,
64 unsigned long offset)
65 {
66 if (small_const_nbits(size)) {
67 unsigned long val;
68
69 if (unlikely(offset >= size))
70 return size;
71
72 val = *addr1 & *addr2 & GENMASK(size - 1, offset);
73 return val ? __ffs(val) : size;
74 }
75
76 return _find_next_and_bit(addr1, addr2, size, offset);
77 }
78 #endif
79
80 #ifndef find_next_zero_bit
81 /**
82 * find_next_zero_bit - find the next cleared bit in a memory region
83 * @addr: The address to base the search on
84 * @size: The bitmap size in bits
85 * @offset: The bitnumber to start searching at
86 *
87 * Returns the bit number of the next zero bit
88 * If no bits are zero, returns @size.
89 */
90 static inline
91 unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
92 unsigned long offset)
93 {
94 if (small_const_nbits(size)) {
95 unsigned long val;
96
97 if (unlikely(offset >= size))
98 return size;
99
100 val = *addr | ~GENMASK(size - 1, offset);
101 return val == ~0UL ? size : ffz(val);
102 }
103
104 return _find_next_zero_bit(addr, size, offset);
105 }
106 #endif
107
108 #ifndef find_first_bit
109 /**
110 * find_first_bit - find the first set bit in a memory region
111 * @addr: The address to start the search at
112 * @size: The maximum number of bits to search
113 *
114 * Returns the bit number of the first set bit.
115 * If no bits are set, returns @size.
116 */
117 static inline
118 unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
119 {
120 if (small_const_nbits(size)) {
121 unsigned long val = *addr & GENMASK(size - 1, 0);
122
123 return val ? __ffs(val) : size;
124 }
125
126 return _find_first_bit(addr, size);
127 }
128 #endif
129
130 #ifndef find_first_and_bit
131 /**
132 * find_first_and_bit - find the first set bit in both memory regions
133 * @addr1: The first address to base the search on
134 * @addr2: The second address to base the search on
135 * @size: The bitmap size in bits
136 *
137 * Returns the bit number for the next set bit
138 * If no bits are set, returns @size.
139 */
140 static inline
141 unsigned long find_first_and_bit(const unsigned long *addr1,
142 const unsigned long *addr2,
143 unsigned long size)
144 {
145 if (small_const_nbits(size)) {
146 unsigned long val = *addr1 & *addr2 & GENMASK(size - 1, 0);
147
148 return val ? __ffs(val) : size;
149 }
150
151 return _find_first_and_bit(addr1, addr2, size);
152 }
153 #endif
154
155 #ifndef find_first_zero_bit
156 /**
157 * find_first_zero_bit - find the first cleared bit in a memory region
158 * @addr: The address to start the search at
159 * @size: The maximum number of bits to search
160 *
161 * Returns the bit number of the first cleared bit.
162 * If no bits are zero, returns @size.
163 */
164 static inline
165 unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
166 {
167 if (small_const_nbits(size)) {
168 unsigned long val = *addr | ~GENMASK(size - 1, 0);
169
170 return val == ~0UL ? size : ffz(val);
171 }
172
173 return _find_first_zero_bit(addr, size);
174 }
175 #endif
176
177 #endif /*__LINUX_FIND_H_ */
178
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