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7#ifndef _LINUX_BITFIELD_H
8#define _LINUX_BITFIELD_H
9
10#include <linux/build_bug.h>
11#include <asm/byteorder.h>
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42#define __bf_shf(x) (__builtin_ffsll(x) - 1)
43
44#define __BF_FIELD_CHECK(_mask, _reg, _val, _pfx) \
45 ({ \
46 BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), \
47 _pfx "mask is not constant"); \
48 BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero"); \
49 BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ? \
50 ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
51 _pfx "value too large for the field"); \
52 BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, \
53 _pfx "type of reg too small for mask"); \
54 __BUILD_BUG_ON_NOT_POWER_OF_2((_mask) + \
55 (1ULL << __bf_shf(_mask))); \
56 })
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64
65#define FIELD_MAX(_mask) \
66 ({ \
67 __BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_MAX: "); \
68 (typeof(_mask))((_mask) >> __bf_shf(_mask)); \
69 })
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77
78#define FIELD_FIT(_mask, _val) \
79 ({ \
80 __BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_FIT: "); \
81 !((((typeof(_mask))_val) << __bf_shf(_mask)) & ~(_mask)); \
82 })
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91
92#define FIELD_PREP(_mask, _val) \
93 ({ \
94 __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
95 ((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask); \
96 })
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106#define FIELD_GET(_mask, _reg) \
107 ({ \
108 __BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
109 (typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \
110 })
111
112extern void __compiletime_error("value doesn't fit into mask")
113__field_overflow(void);
114extern void __compiletime_error("bad bitfield mask")
115__bad_mask(void);
116static __always_inline u64 field_multiplier(u64 field)
117{
118 if ((field | (field - 1)) & ((field | (field - 1)) + 1))
119 __bad_mask();
120 return field & -field;
121}
122static __always_inline u64 field_mask(u64 field)
123{
124 return field / field_multiplier(field);
125}
126#define field_max(field) ((typeof(field))field_mask(field))
127#define ____MAKE_OP(type,base,to,from) \
128static __always_inline __##type type##_encode_bits(base v, base field) \
129{ \
130 if (__builtin_constant_p(v) && (v & ~field_mask(field))) \
131 __field_overflow(); \
132 return to((v & field_mask(field)) * field_multiplier(field)); \
133} \
134static __always_inline __##type type##_replace_bits(__##type old, \
135 base val, base field) \
136{ \
137 return (old & ~to(field)) | type##_encode_bits(val, field); \
138} \
139static __always_inline void type##p_replace_bits(__##type *p, \
140 base val, base field) \
141{ \
142 *p = (*p & ~to(field)) | type##_encode_bits(val, field); \
143} \
144static __always_inline base type##_get_bits(__##type v, base field) \
145{ \
146 return (from(v) & field)/field_multiplier(field); \
147}
148#define __MAKE_OP(size) \
149 ____MAKE_OP(le##size,u##size,cpu_to_le##size,le##size##_to_cpu) \
150 ____MAKE_OP(be##size,u##size,cpu_to_be##size,be##size##_to_cpu) \
151 ____MAKE_OP(u##size,u##size,,)
152____MAKE_OP(u8,u8,,)
153__MAKE_OP(16)
154__MAKE_OP(32)
155__MAKE_OP(64)
156#undef __MAKE_OP
157#undef ____MAKE_OP
158
159#endif
160