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1// SPDX-License-Identifier: MIT2/*3 * Copyright 2023 Advanced Micro Devices, Inc.4 *5 * Permission is hereby granted, free of charge, to any person obtaining a6 * copy of this software and associated documentation files (the "Software"),7 * to deal in the Software without restriction, including without limitation8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,9 * and/or sell copies of the Software, and to permit persons to whom the10 * Software is furnished to do so, subject to the following conditions:11 *12 * The above copyright notice and this permission notice shall be included in13 * all copies or substantial portions of the Software.14 *15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR21 * OTHER DEALINGS IN THE SOFTWARE.22 *23 * Authors: AMD24 *25 */26#include "dm_services.h"27#include "bw_fixed.h"28 29#define MAX_I64 \30	((int64_t)((1ULL << 63) - 1))31 32#define MIN_I64 \33	(-MAX_I64 - 1)34 35#define FRACTIONAL_PART_MASK \36	((1ULL << BW_FIXED_BITS_PER_FRACTIONAL_PART) - 1)37 38#define GET_FRACTIONAL_PART(x) \39	(FRACTIONAL_PART_MASK & (x))40 41static uint64_t abs_i64(int64_t arg)42{43	if (arg >= 0)44		return (uint64_t)(arg);45	else46		return (uint64_t)(-arg);47}48 49struct bw_fixed bw_int_to_fixed_nonconst(int64_t value)50{51	struct bw_fixed res;52 53	ASSERT(value < BW_FIXED_MAX_I32 && value > BW_FIXED_MIN_I32);54	res.value = value << BW_FIXED_BITS_PER_FRACTIONAL_PART;55	return res;56}57 58struct bw_fixed bw_frc_to_fixed(int64_t numerator, int64_t denominator)59{60	struct bw_fixed res;61	bool arg1_negative = numerator < 0;62	bool arg2_negative = denominator < 0;63	uint64_t arg1_value;64	uint64_t arg2_value;65	uint64_t remainder;66 67	/* determine integer part */68	uint64_t res_value;69 70	ASSERT(denominator != 0);71 72	arg1_value = abs_i64(numerator);73	arg2_value = abs_i64(denominator);74	res_value = div64_u64_rem(arg1_value, arg2_value, &remainder);75 76	ASSERT(res_value <= BW_FIXED_MAX_I32);77 78	/* determine fractional part */79	{80		uint32_t i = BW_FIXED_BITS_PER_FRACTIONAL_PART;81 82		do {83			remainder <<= 1;84 85			res_value <<= 1;86 87			if (remainder >= arg2_value) {88				res_value |= 1;89				remainder -= arg2_value;90			}91		} while (--i != 0);92	}93 94	/* round up LSB */95	{96		uint64_t summand = (remainder << 1) >= arg2_value;97 98		ASSERT(res_value <= MAX_I64 - summand);99 100		res_value += summand;101	}102 103	res.value = (int64_t)(res_value);104 105	if (arg1_negative ^ arg2_negative)106		res.value = -res.value;107	return res;108}109 110struct bw_fixed bw_floor2(const struct bw_fixed arg,111			  const struct bw_fixed significance)112{113	struct bw_fixed result;114	int64_t multiplicand;115 116	multiplicand = div64_s64(arg.value, abs_i64(significance.value));117	result.value = abs_i64(significance.value) * multiplicand;118	ASSERT(abs_i64(result.value) <= abs_i64(arg.value));119	return result;120}121 122struct bw_fixed bw_ceil2(const struct bw_fixed arg,123			 const struct bw_fixed significance)124{125	struct bw_fixed result;126	int64_t multiplicand;127 128	multiplicand = div64_s64(arg.value, abs_i64(significance.value));129	result.value = abs_i64(significance.value) * multiplicand;130	if (abs_i64(result.value) < abs_i64(arg.value)) {131		if (arg.value < 0)132			result.value -= abs_i64(significance.value);133		else134			result.value += abs_i64(significance.value);135	}136	return result;137}138 139struct bw_fixed bw_mul(const struct bw_fixed arg1, const struct bw_fixed arg2)140{141	struct bw_fixed res;142 143	bool arg1_negative = arg1.value < 0;144	bool arg2_negative = arg2.value < 0;145 146	uint64_t arg1_value = abs_i64(arg1.value);147	uint64_t arg2_value = abs_i64(arg2.value);148 149	uint64_t arg1_int = BW_FIXED_GET_INTEGER_PART(arg1_value);150	uint64_t arg2_int = BW_FIXED_GET_INTEGER_PART(arg2_value);151 152	uint64_t arg1_fra = GET_FRACTIONAL_PART(arg1_value);153	uint64_t arg2_fra = GET_FRACTIONAL_PART(arg2_value);154 155	uint64_t tmp;156 157	res.value = arg1_int * arg2_int;158 159	ASSERT(res.value <= BW_FIXED_MAX_I32);160 161	res.value <<= BW_FIXED_BITS_PER_FRACTIONAL_PART;162 163	tmp = arg1_int * arg2_fra;164 165	ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));166 167	res.value += tmp;168 169	tmp = arg2_int * arg1_fra;170 171	ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));172 173	res.value += tmp;174 175	tmp = arg1_fra * arg2_fra;176 177	tmp = (tmp >> BW_FIXED_BITS_PER_FRACTIONAL_PART) +178		(tmp >= (uint64_t)(bw_frc_to_fixed(1, 2).value));179 180	ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));181 182	res.value += tmp;183 184	if (arg1_negative ^ arg2_negative)185		res.value = -res.value;186	return res;187}188 189