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15#ifndef _LINUX_BITFIELD_H
16#define _LINUX_BITFIELD_H
17
18#include <linux/bug.h>
19#include <asm/byteorder.h>
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50#define __bf_shf(x) (__builtin_ffsll(x) - 1)
51
52#define __BF_FIELD_CHECK(_mask, _reg, _val, _pfx) \
53 ({ \
54 BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), \
55 _pfx "mask is not constant"); \
56 BUILD_BUG_ON_MSG(!(_mask), _pfx "mask is zero"); \
57 BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ? \
58 ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
59 _pfx "value too large for the field"); \
60 BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, \
61 _pfx "type of reg too small for mask"); \
62 __BUILD_BUG_ON_NOT_POWER_OF_2((_mask) + \
63 (1ULL << __bf_shf(_mask))); \
64 })
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71
72
73#define FIELD_FIT(_mask, _val) \
74 ({ \
75 __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_FIT: "); \
76 !((((typeof(_mask))_val) << __bf_shf(_mask)) & ~(_mask)); \
77 })
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86
87#define FIELD_PREP(_mask, _val) \
88 ({ \
89 __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
90 ((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask); \
91 })
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100
101#define FIELD_GET(_mask, _reg) \
102 ({ \
103 __BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
104 (typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \
105 })
106
107extern void __compiletime_error("value doesn't fit into mask")
108__field_overflow(void);
109extern void __compiletime_error("bad bitfield mask")
110__bad_mask(void);
111
112static __always_inline u64 field_multiplier(u64 field)
113{
114 if ((field | (field - 1)) & ((field | (field - 1)) + 1))
115 __bad_mask();
116 return field & -field;
117}
118
119static __always_inline u64 field_mask(u64 field)
120{
121 return field / field_multiplier(field);
122}
123
124#define ____MAKE_OP(type, base, to, from) \
125static __always_inline __##type type##_encode_bits(base v, base field) \
126{ \
127 if (__builtin_constant_p(v) && (v & ~field_mask(field))) \
128 __field_overflow(); \
129 return to((v & field_mask(field)) * field_multiplier(field)); \
130} \
131static __always_inline __##type type##_replace_bits(__##type old, \
132 base val, base field) \
133{ \
134 return (old & ~to(field)) | type##_encode_bits(val, field); \
135} \
136static __always_inline void type##p_replace_bits(__##type * p, \
137 base val, base field) \
138{ \
139 *p = (*p & ~to(field)) | type##_encode_bits(val, field); \
140} \
141static __always_inline base type##_get_bits(__##type v, base field) \
142{ \
143 return (from(v) & field) / field_multiplier(field); \
144}
145
146#define __MAKE_OP(size) \
147 ____MAKE_OP(le##size, u##size, cpu_to_le##size, le##size##_to_cpu) \
148 ____MAKE_OP(be##size, u##size, cpu_to_be##size, be##size##_to_cpu) \
149 ____MAKE_OP(u##size, u##size, ,)
150
151____MAKE_OP(u8, u8, ,)
152__MAKE_OP(16)
153__MAKE_OP(32)
154__MAKE_OP(64)
155
156#undef __MAKE_OP
157#undef ____MAKE_OP
158
159#endif
160