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771fe6b9 JG |
1 | /* |
2 | * Copyright 2009 Red Hat Inc. | |
3 | * | |
4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
5 | * copy of this software and associated documentation files (the "Software"), | |
6 | * to deal in the Software without restriction, including without limitation | |
7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
8 | * and/or sell copies of the Software, and to permit persons to whom the | |
9 | * Software is furnished to do so, subject to the following conditions: | |
10 | * | |
11 | * The above copyright notice and this permission notice shall be included in | |
12 | * all copies or substantial portions of the Software. | |
13 | * | |
14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
17 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
18 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
20 | * OTHER DEALINGS IN THE SOFTWARE. | |
21 | * | |
22 | * Authors: Dave Airlie | |
210a0b9e | 23 | * Christian König |
771fe6b9 | 24 | */ |
68adac5e BS |
25 | #ifndef DRM_FIXED_H |
26 | #define DRM_FIXED_H | |
771fe6b9 | 27 | |
210a0b9e AD |
28 | #include <linux/math64.h> |
29 | ||
68adac5e | 30 | typedef union dfixed { |
771fe6b9 JG |
31 | u32 full; |
32 | } fixed20_12; | |
33 | ||
34 | ||
68adac5e BS |
35 | #define dfixed_const(A) (u32)(((A) << 12))/* + ((B + 0.000122)*4096)) */ |
36 | #define dfixed_const_half(A) (u32)(((A) << 12) + 2048) | |
37 | #define dfixed_const_666(A) (u32)(((A) << 12) + 2731) | |
38 | #define dfixed_const_8(A) (u32)(((A) << 12) + 3277) | |
39 | #define dfixed_mul(A, B) ((u64)((u64)(A).full * (B).full + 2048) >> 12) | |
40 | #define dfixed_init(A) { .full = dfixed_const((A)) } | |
41 | #define dfixed_init_half(A) { .full = dfixed_const_half((A)) } | |
42 | #define dfixed_trunc(A) ((A).full >> 12) | |
f7f6c340 | 43 | #define dfixed_frac(A) ((A).full & ((1 << 12) - 1)) |
771fe6b9 | 44 | |
68adac5e | 45 | static inline u32 dfixed_floor(fixed20_12 A) |
69b3b5e5 | 46 | { |
68adac5e | 47 | u32 non_frac = dfixed_trunc(A); |
69b3b5e5 | 48 | |
68adac5e | 49 | return dfixed_const(non_frac); |
69b3b5e5 AD |
50 | } |
51 | ||
68adac5e | 52 | static inline u32 dfixed_ceil(fixed20_12 A) |
69b3b5e5 | 53 | { |
68adac5e | 54 | u32 non_frac = dfixed_trunc(A); |
69b3b5e5 | 55 | |
68adac5e BS |
56 | if (A.full > dfixed_const(non_frac)) |
57 | return dfixed_const(non_frac + 1); | |
69b3b5e5 | 58 | else |
68adac5e | 59 | return dfixed_const(non_frac); |
69b3b5e5 AD |
60 | } |
61 | ||
68adac5e | 62 | static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B) |
771fe6b9 JG |
63 | { |
64 | u64 tmp = ((u64)A.full << 13); | |
65 | ||
66 | do_div(tmp, B.full); | |
67 | tmp += 1; | |
68 | tmp /= 2; | |
69 | return lower_32_bits(tmp); | |
70 | } | |
210a0b9e AD |
71 | |
72 | #define DRM_FIXED_POINT 32 | |
73 | #define DRM_FIXED_ONE (1ULL << DRM_FIXED_POINT) | |
74 | #define DRM_FIXED_DECIMAL_MASK (DRM_FIXED_ONE - 1) | |
75 | #define DRM_FIXED_DIGITS_MASK (~DRM_FIXED_DECIMAL_MASK) | |
76 | ||
77 | static inline s64 drm_int2fixp(int a) | |
78 | { | |
79 | return ((s64)a) << DRM_FIXED_POINT; | |
80 | } | |
81 | ||
82 | static inline int drm_fixp2int(int64_t a) | |
83 | { | |
84 | return ((s64)a) >> DRM_FIXED_POINT; | |
85 | } | |
86 | ||
a838834b | 87 | static inline unsigned drm_fixp_msbset(int64_t a) |
210a0b9e AD |
88 | { |
89 | unsigned shift, sign = (a >> 63) & 1; | |
90 | ||
91 | for (shift = 62; shift > 0; --shift) | |
a838834b | 92 | if (((a >> shift) & 1) != sign) |
210a0b9e AD |
93 | return shift; |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | static inline s64 drm_fixp_mul(s64 a, s64 b) | |
99 | { | |
100 | unsigned shift = drm_fixp_msbset(a) + drm_fixp_msbset(b); | |
101 | s64 result; | |
102 | ||
a838834b AD |
103 | if (shift > 61) { |
104 | shift = shift - 61; | |
105 | a >>= (shift >> 1) + (shift & 1); | |
210a0b9e AD |
106 | b >>= shift >> 1; |
107 | } else | |
108 | shift = 0; | |
109 | ||
110 | result = a * b; | |
111 | ||
112 | if (shift > DRM_FIXED_POINT) | |
113 | return result << (shift - DRM_FIXED_POINT); | |
114 | ||
115 | if (shift < DRM_FIXED_POINT) | |
116 | return result >> (DRM_FIXED_POINT - shift); | |
117 | ||
118 | return result; | |
119 | } | |
120 | ||
121 | static inline s64 drm_fixp_div(s64 a, s64 b) | |
122 | { | |
a838834b | 123 | unsigned shift = 62 - drm_fixp_msbset(a); |
210a0b9e AD |
124 | s64 result; |
125 | ||
126 | a <<= shift; | |
127 | ||
128 | if (shift < DRM_FIXED_POINT) | |
129 | b >>= (DRM_FIXED_POINT - shift); | |
130 | ||
131 | result = div64_s64(a, b); | |
132 | ||
133 | if (shift > DRM_FIXED_POINT) | |
134 | return result >> (shift - DRM_FIXED_POINT); | |
135 | ||
136 | return result; | |
137 | } | |
138 | ||
139 | static inline s64 drm_fixp_exp(s64 x) | |
140 | { | |
141 | s64 tolerance = div64_s64(DRM_FIXED_ONE, 1000000); | |
142 | s64 sum = DRM_FIXED_ONE, term, y = x; | |
143 | u64 count = 1; | |
144 | ||
145 | if (x < 0) | |
146 | y = -1 * x; | |
147 | ||
148 | term = y; | |
149 | ||
150 | while (term >= tolerance) { | |
151 | sum = sum + term; | |
152 | count = count + 1; | |
153 | term = drm_fixp_mul(term, div64_s64(y, count)); | |
154 | } | |
155 | ||
156 | if (x < 0) | |
a838834b | 157 | sum = drm_fixp_div(DRM_FIXED_ONE, sum); |
210a0b9e AD |
158 | |
159 | return sum; | |
160 | } | |
161 | ||
771fe6b9 | 162 | #endif |