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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
23 */
24#ifndef DRM_FIXED_H
25#define DRM_FIXED_H
26
27typedef union dfixed {
28 u32 full;
29} fixed20_12;
30
31
32#define dfixed_const(A) (u32)(((A) << 12))/* + ((B + 0.000122)*4096)) */
33#define dfixed_const_half(A) (u32)(((A) << 12) + 2048)
34#define dfixed_const_666(A) (u32)(((A) << 12) + 2731)
35#define dfixed_const_8(A) (u32)(((A) << 12) + 3277)
36#define dfixed_mul(A, B) ((u64)((u64)(A).full * (B).full + 2048) >> 12)
37#define dfixed_init(A) { .full = dfixed_const((A)) }
38#define dfixed_init_half(A) { .full = dfixed_const_half((A)) }
39#define dfixed_trunc(A) ((A).full >> 12)
40
41static inline u32 dfixed_floor(fixed20_12 A)
42{
43 u32 non_frac = dfixed_trunc(A);
44
45 return dfixed_const(non_frac);
46}
47
48static inline u32 dfixed_ceil(fixed20_12 A)
49{
50 u32 non_frac = dfixed_trunc(A);
51
52 if (A.full > dfixed_const(non_frac))
53 return dfixed_const(non_frac + 1);
54 else
55 return dfixed_const(non_frac);
56}
57
58static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B)
59{
60 u64 tmp = ((u64)A.full << 13);
61
62 do_div(tmp, B.full);
63 tmp += 1;
64 tmp /= 2;
65 return lower_32_bits(tmp);
66}
67#endif
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
23 * Christian König
24 */
25#ifndef DRM_FIXED_H
26#define DRM_FIXED_H
27
28#include <linux/math64.h>
29
30typedef union dfixed {
31 u32 full;
32} fixed20_12;
33
34
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)
43#define dfixed_frac(A) ((A).full & ((1 << 12) - 1))
44
45static inline u32 dfixed_floor(fixed20_12 A)
46{
47 u32 non_frac = dfixed_trunc(A);
48
49 return dfixed_const(non_frac);
50}
51
52static inline u32 dfixed_ceil(fixed20_12 A)
53{
54 u32 non_frac = dfixed_trunc(A);
55
56 if (A.full > dfixed_const(non_frac))
57 return dfixed_const(non_frac + 1);
58 else
59 return dfixed_const(non_frac);
60}
61
62static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B)
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}
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
77static inline s64 drm_int2fixp(int a)
78{
79 return ((s64)a) << DRM_FIXED_POINT;
80}
81
82static inline int drm_fixp2int(int64_t a)
83{
84 return ((s64)a) >> DRM_FIXED_POINT;
85}
86
87static inline unsigned drm_fixp_msbset(int64_t a)
88{
89 unsigned shift, sign = (a >> 63) & 1;
90
91 for (shift = 62; shift > 0; --shift)
92 if (((a >> shift) & 1) != sign)
93 return shift;
94
95 return 0;
96}
97
98static 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
103 if (shift > 61) {
104 shift = shift - 61;
105 a >>= (shift >> 1) + (shift & 1);
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
121static inline s64 drm_fixp_div(s64 a, s64 b)
122{
123 unsigned shift = 62 - drm_fixp_msbset(a);
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
139static 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)
157 sum = drm_fixp_div(DRM_FIXED_ONE, sum);
158
159 return sum;
160}
161
162#endif