1 /* $NetBSD: amdgpu_bw_fixed.c,v 1.2 2021/12/18 23:45:01 riastradh Exp $ */ 2 3 /* 4 * Copyright 2015 Advanced Micro Devices, Inc. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22 * OTHER DEALINGS IN THE SOFTWARE. 23 * 24 * Authors: AMD 25 * 26 */ 27 #include <sys/cdefs.h> 28 __KERNEL_RCSID(0, "$NetBSD: amdgpu_bw_fixed.c,v 1.2 2021/12/18 23:45:01 riastradh Exp $"); 29 30 #include "dm_services.h" 31 #include "bw_fixed.h" 32 33 34 #define MIN_I64 \ 35 (int64_t)(-(1LL << 63)) 36 37 #define MAX_I64 \ 38 (int64_t)((1ULL << 63) - 1) 39 40 #define FRACTIONAL_PART_MASK \ 41 ((1ULL << BW_FIXED_BITS_PER_FRACTIONAL_PART) - 1) 42 43 #define GET_FRACTIONAL_PART(x) \ 44 (FRACTIONAL_PART_MASK & (x)) 45 46 static uint64_t abs_i64(int64_t arg) 47 { 48 if (arg >= 0) 49 return (uint64_t)(arg); 50 else 51 return (uint64_t)(-arg); 52 } 53 54 struct bw_fixed bw_int_to_fixed_nonconst(int64_t value) 55 { 56 struct bw_fixed res; 57 ASSERT(value < BW_FIXED_MAX_I32 && value > BW_FIXED_MIN_I32); 58 res.value = value << BW_FIXED_BITS_PER_FRACTIONAL_PART; 59 return res; 60 } 61 62 struct bw_fixed bw_frc_to_fixed(int64_t numerator, int64_t denominator) 63 { 64 struct bw_fixed res; 65 bool arg1_negative = numerator < 0; 66 bool arg2_negative = denominator < 0; 67 uint64_t arg1_value; 68 uint64_t arg2_value; 69 uint64_t remainder; 70 71 /* determine integer part */ 72 uint64_t res_value; 73 74 ASSERT(denominator != 0); 75 76 arg1_value = abs_i64(numerator); 77 arg2_value = abs_i64(denominator); 78 res_value = div64_u64_rem(arg1_value, arg2_value, &remainder); 79 80 ASSERT(res_value <= BW_FIXED_MAX_I32); 81 82 /* determine fractional part */ 83 { 84 uint32_t i = BW_FIXED_BITS_PER_FRACTIONAL_PART; 85 86 do 87 { 88 remainder <<= 1; 89 90 res_value <<= 1; 91 92 if (remainder >= arg2_value) 93 { 94 res_value |= 1; 95 remainder -= arg2_value; 96 } 97 } while (--i != 0); 98 } 99 100 /* round up LSB */ 101 { 102 uint64_t summand = (remainder << 1) >= arg2_value; 103 104 ASSERT(res_value <= MAX_I64 - summand); 105 106 res_value += summand; 107 } 108 109 res.value = (int64_t)(res_value); 110 111 if (arg1_negative ^ arg2_negative) 112 res.value = -res.value; 113 return res; 114 } 115 116 struct bw_fixed bw_floor2( 117 const struct bw_fixed arg, 118 const struct bw_fixed significance) 119 { 120 struct bw_fixed result; 121 int64_t multiplicand; 122 123 multiplicand = div64_s64(arg.value, abs_i64(significance.value)); 124 result.value = abs_i64(significance.value) * multiplicand; 125 ASSERT(abs_i64(result.value) <= abs_i64(arg.value)); 126 return result; 127 } 128 129 struct bw_fixed bw_ceil2( 130 const struct bw_fixed arg, 131 const struct bw_fixed significance) 132 { 133 struct bw_fixed result; 134 int64_t multiplicand; 135 136 multiplicand = div64_s64(arg.value, abs_i64(significance.value)); 137 result.value = abs_i64(significance.value) * multiplicand; 138 if (abs_i64(result.value) < abs_i64(arg.value)) { 139 if (arg.value < 0) 140 result.value -= abs_i64(significance.value); 141 else 142 result.value += abs_i64(significance.value); 143 } 144 return result; 145 } 146 147 struct bw_fixed bw_mul(const struct bw_fixed arg1, const struct bw_fixed arg2) 148 { 149 struct bw_fixed res; 150 151 bool arg1_negative = arg1.value < 0; 152 bool arg2_negative = arg2.value < 0; 153 154 uint64_t arg1_value = abs_i64(arg1.value); 155 uint64_t arg2_value = abs_i64(arg2.value); 156 157 uint64_t arg1_int = BW_FIXED_GET_INTEGER_PART(arg1_value); 158 uint64_t arg2_int = BW_FIXED_GET_INTEGER_PART(arg2_value); 159 160 uint64_t arg1_fra = GET_FRACTIONAL_PART(arg1_value); 161 uint64_t arg2_fra = GET_FRACTIONAL_PART(arg2_value); 162 163 uint64_t tmp; 164 165 res.value = arg1_int * arg2_int; 166 167 ASSERT(res.value <= BW_FIXED_MAX_I32); 168 169 res.value <<= BW_FIXED_BITS_PER_FRACTIONAL_PART; 170 171 tmp = arg1_int * arg2_fra; 172 173 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value)); 174 175 res.value += tmp; 176 177 tmp = arg2_int * arg1_fra; 178 179 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value)); 180 181 res.value += tmp; 182 183 tmp = arg1_fra * arg2_fra; 184 185 tmp = (tmp >> BW_FIXED_BITS_PER_FRACTIONAL_PART) + 186 (tmp >= (uint64_t)(bw_frc_to_fixed(1, 2).value)); 187 188 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value)); 189 190 res.value += tmp; 191 192 if (arg1_negative ^ arg2_negative) 193 res.value = -res.value; 194 return res; 195 } 196 197
Indexes created Thu Sep 25 08:09:54 GMT 2025