xref: /freebsd/sys/compat/linuxkpi/common/include/linux/bitfield.h (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2020 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  * $FreeBSD$
31  */
32 
33 #ifndef	_LINUX_BITFIELD_H
34 #define	_LINUX_BITFIELD_H
35 
36 #include <linux/types.h>
37 #include <asm/byteorder.h>
38 
39 /* Use largest possible type. */
40 static inline uint64_t ___lsb(uint64_t f) { return (f & -f); }
41 static inline uint64_t ___bitmask(uint64_t f) { return (f / ___lsb(f)); }
42 
43 #define	_uX_get_bits(_n)						\
44 	static __inline uint ## _n ## _t				\
45 	u ## _n ## _get_bits(uint ## _n ## _t v, uint ## _n ## _t f)	\
46 	{								\
47 		return ((v & f) / ___lsb(f));				\
48 	}
49 
50 _uX_get_bits(64)
51 _uX_get_bits(32)
52 _uX_get_bits(16)
53 _uX_get_bits(8)
54 
55 #define	_leX_get_bits(_n)						\
56 	static __inline uint ## _n ## _t				\
57 	le ## _n ## _get_bits(__le ## _n v, uint ## _n ## _t f)		\
58 	{								\
59 		return ((le ## _n ## _to_cpu(v) & f) / ___lsb(f));	\
60 	}
61 
62 _leX_get_bits(64)
63 _leX_get_bits(32)
64 _leX_get_bits(16)
65 
66 #define	_uX_encode_bits(_n)						\
67 	static __inline uint ## _n ## _t				\
68 	u ## _n ## _encode_bits(uint ## _n ## _t v, uint ## _n ## _t f)	\
69 	{								\
70 		return ((v & ___bitmask(f)) * ___lsb(f));		\
71 	}
72 
73 _uX_encode_bits(64)
74 _uX_encode_bits(32)
75 _uX_encode_bits(16)
76 _uX_encode_bits(8)
77 
78 #define	_leX_encode_bits(_n)						\
79 	static __inline uint ## _n ## _t				\
80 	le ## _n ## _encode_bits(__le ## _n v, uint ## _n ## _t f)	\
81 	{								\
82 		return (cpu_to_le ## _n((v & ___bitmask(f)) * ___lsb(f))); \
83 	}
84 
85 _leX_encode_bits(64)
86 _leX_encode_bits(32)
87 _leX_encode_bits(16)
88 
89 static __inline void
90 le32p_replace_bits(uint32_t *p, uint32_t v, uint32_t f)
91 {
92 
93 	*p = (*p & ~(cpu_to_le32(f))) | le32_encode_bits(v, f);
94 }
95 
96 #define	__bf_shf(x)	(__builtin_ffsll(x) - 1)
97 
98 #define	FIELD_PREP(_mask, _value)					\
99 	(((typeof(_mask))(_value) << __bf_shf(_mask)) & (_mask))
100 
101 #define	FIELD_GET(_mask, _value)					\
102 	((typeof(_mask))(((_value) & (_mask)) >> __bf_shf(_mask)))
103 
104 #endif	/* _LINUX_BITFIELD_H */
105