1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2020-2024 The FreeBSD Foundation
5 *
6 * This software was developed by Björn Zeeb under sponsorship from
7 * the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following 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 AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #ifndef _LINUXKPI_LINUX_BITFIELD_H
32 #define _LINUXKPI_LINUX_BITFIELD_H
33
34 #include <linux/types.h>
35 #include <asm/byteorder.h>
36
37 /* Use largest possible type. */
___lsb(uint64_t f)38 static inline uint64_t ___lsb(uint64_t f) { return (f & -f); }
___bitmask(uint64_t f)39 static inline uint64_t ___bitmask(uint64_t f) { return (f / ___lsb(f)); }
40
41 #define _uX_get_bits(_n) \
42 static __inline uint ## _n ## _t \
43 u ## _n ## _get_bits(uint ## _n ## _t v, uint ## _n ## _t f) \
44 { \
45 return ((v & f) / ___lsb(f)); \
46 }
47
48 _uX_get_bits(64)
49 _uX_get_bits(32)
50 _uX_get_bits(16)
51 _uX_get_bits(8)
52
53 #define _leX_get_bits(_n) \
54 static __inline uint ## _n ## _t \
55 le ## _n ## _get_bits(__le ## _n v, uint ## _n ## _t f) \
56 { \
57 return ((le ## _n ## _to_cpu(v) & f) / ___lsb(f)); \
58 }
59
60 _leX_get_bits(64)
61 _leX_get_bits(32)
62 _leX_get_bits(16)
63
64 #define _uX_encode_bits(_n) \
65 static __inline uint ## _n ## _t \
66 u ## _n ## _encode_bits(uint ## _n ## _t v, uint ## _n ## _t f) \
67 { \
68 return ((v & ___bitmask(f)) * ___lsb(f)); \
69 }
70
71 _uX_encode_bits(64)
72 _uX_encode_bits(32)
73 _uX_encode_bits(16)
74 _uX_encode_bits(8)
75
76 #define _leX_encode_bits(_n) \
77 static __inline uint ## _n ## _t \
78 le ## _n ## _encode_bits(__le ## _n v, uint ## _n ## _t f) \
79 { \
80 return (cpu_to_le ## _n((v & ___bitmask(f)) * ___lsb(f))); \
81 }
82
83 _leX_encode_bits(64)
84 _leX_encode_bits(32)
85 _leX_encode_bits(16)
86
87 #define _leXp_replace_bits(_n) \
88 static __inline void \
89 le ## _n ## p_replace_bits(uint ## _n ## _t *p, \
90 uint ## _n ## _t v, uint ## _n ## _t f) \
91 { \
92 *p = (*p & ~(cpu_to_le ## _n(f))) | \
93 le ## _n ## _encode_bits(v, f); \
94 }
95
96 _leXp_replace_bits(64)
97 _leXp_replace_bits(32)
98 _leXp_replace_bits(16)
99
100 #define _uXp_replace_bits(_n) \
101 static __inline void \
102 u ## _n ## p_replace_bits(uint ## _n ## _t *p, \
103 uint ## _n ## _t v, uint ## _n ## _t f) \
104 { \
105 *p = (*p & ~f) | u ## _n ## _encode_bits(v, f); \
106 }
107
108 _uXp_replace_bits(64)
109 _uXp_replace_bits(32)
110 _uXp_replace_bits(16)
111 _uXp_replace_bits(8)
112
113 #define _uX_replace_bits(_n) \
114 static __inline uint ## _n ## _t \
115 u ## _n ## _replace_bits(uint ## _n ## _t p, \
116 uint ## _n ## _t v, uint ## _n ## _t f) \
117 { \
118 return ((p & ~f) | u ## _n ## _encode_bits(v, f)); \
119 }
120
121 _uX_replace_bits(64)
122 _uX_replace_bits(32)
123 _uX_replace_bits(16)
124 _uX_replace_bits(8)
125
126 #define __bf_shf(x) (__builtin_ffsll(x) - 1)
127
128 #define FIELD_FIT(_mask, _value) \
129 (!(((typeof(_mask))(_value) << __bf_shf(_mask)) & ~(_mask)))
130
131 #define FIELD_PREP(_mask, _value) \
132 (((typeof(_mask))(_value) << __bf_shf(_mask)) & (_mask))
133
134 /* Likely would need extra sanity checks compared to FIELD_PREP()? */
135 #define FIELD_PREP_CONST(_mask, _value) \
136 (((typeof(_mask))(_value) << __bf_shf(_mask)) & (_mask))
137
138 #define FIELD_GET(_mask, _value) \
139 ((typeof(_mask))(((_value) & (_mask)) >> __bf_shf(_mask)))
140
141 #endif /* _LINUXKPI_LINUX_BITFIELD_H */
142