![Bob Moore](/assets/img/avatar_default.png)
This type was introduced as the code was migrated from ACPI 1.0 (with 32-bit AML integers) to ACPI 2.0 (with 64-bit integers). It is now obsolete and this change removes it from the ACPICA code base, replaced by u64. The original typedef has been retained for now for compatibility with existing device driver code. Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
308 lines
9 KiB
C
308 lines
9 KiB
C
/*******************************************************************************
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*
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* Module Name: utmath - Integer math support routines
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*
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******************************************************************************/
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/*
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* Copyright (C) 2000 - 2010, Intel Corp.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions, and the following disclaimer,
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* without modification.
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* 2. Redistributions in binary form must reproduce at minimum a disclaimer
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* substantially similar to the "NO WARRANTY" disclaimer below
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* ("Disclaimer") and any redistribution must be conditioned upon
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* including a substantially similar Disclaimer requirement for further
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* binary redistribution.
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* 3. Neither the names of the above-listed copyright holders nor the names
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* of any contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* Alternatively, this software may be distributed under the terms of the
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* GNU General Public License ("GPL") version 2 as published by the Free
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* Software Foundation.
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*
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* NO WARRANTY
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGES.
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*/
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#include <acpi/acpi.h>
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#include "accommon.h"
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#define _COMPONENT ACPI_UTILITIES
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ACPI_MODULE_NAME("utmath")
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/*
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* Support for double-precision integer divide. This code is included here
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* in order to support kernel environments where the double-precision math
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* library is not available.
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*/
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#ifndef ACPI_USE_NATIVE_DIVIDE
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/*******************************************************************************
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*
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* FUNCTION: acpi_ut_short_divide
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*
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* PARAMETERS: Dividend - 64-bit dividend
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* Divisor - 32-bit divisor
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* out_quotient - Pointer to where the quotient is returned
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* out_remainder - Pointer to where the remainder is returned
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*
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* RETURN: Status (Checks for divide-by-zero)
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*
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* DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits)
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* divide and modulo. The result is a 64-bit quotient and a
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* 32-bit remainder.
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*
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******************************************************************************/
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acpi_status
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acpi_ut_short_divide(u64 dividend,
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u32 divisor, u64 *out_quotient, u32 *out_remainder)
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{
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union uint64_overlay dividend_ovl;
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union uint64_overlay quotient;
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u32 remainder32;
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ACPI_FUNCTION_TRACE(ut_short_divide);
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/* Always check for a zero divisor */
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if (divisor == 0) {
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ACPI_ERROR((AE_INFO, "Divide by zero"));
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return_ACPI_STATUS(AE_AML_DIVIDE_BY_ZERO);
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}
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dividend_ovl.full = dividend;
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/*
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* The quotient is 64 bits, the remainder is always 32 bits,
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* and is generated by the second divide.
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*/
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ACPI_DIV_64_BY_32(0, dividend_ovl.part.hi, divisor,
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quotient.part.hi, remainder32);
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ACPI_DIV_64_BY_32(remainder32, dividend_ovl.part.lo, divisor,
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quotient.part.lo, remainder32);
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/* Return only what was requested */
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if (out_quotient) {
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*out_quotient = quotient.full;
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}
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if (out_remainder) {
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*out_remainder = remainder32;
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}
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return_ACPI_STATUS(AE_OK);
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}
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/*******************************************************************************
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*
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* FUNCTION: acpi_ut_divide
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*
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* PARAMETERS: in_dividend - Dividend
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* in_divisor - Divisor
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* out_quotient - Pointer to where the quotient is returned
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* out_remainder - Pointer to where the remainder is returned
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*
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* RETURN: Status (Checks for divide-by-zero)
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*
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* DESCRIPTION: Perform a divide and modulo.
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*
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******************************************************************************/
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acpi_status
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acpi_ut_divide(u64 in_dividend,
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u64 in_divisor, u64 *out_quotient, u64 *out_remainder)
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{
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union uint64_overlay dividend;
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union uint64_overlay divisor;
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union uint64_overlay quotient;
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union uint64_overlay remainder;
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union uint64_overlay normalized_dividend;
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union uint64_overlay normalized_divisor;
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u32 partial1;
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union uint64_overlay partial2;
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union uint64_overlay partial3;
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ACPI_FUNCTION_TRACE(ut_divide);
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/* Always check for a zero divisor */
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if (in_divisor == 0) {
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ACPI_ERROR((AE_INFO, "Divide by zero"));
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return_ACPI_STATUS(AE_AML_DIVIDE_BY_ZERO);
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}
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divisor.full = in_divisor;
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dividend.full = in_dividend;
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if (divisor.part.hi == 0) {
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/*
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* 1) Simplest case is where the divisor is 32 bits, we can
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* just do two divides
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*/
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remainder.part.hi = 0;
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/*
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* The quotient is 64 bits, the remainder is always 32 bits,
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* and is generated by the second divide.
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*/
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ACPI_DIV_64_BY_32(0, dividend.part.hi, divisor.part.lo,
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quotient.part.hi, partial1);
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ACPI_DIV_64_BY_32(partial1, dividend.part.lo, divisor.part.lo,
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quotient.part.lo, remainder.part.lo);
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}
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else {
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/*
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* 2) The general case where the divisor is a full 64 bits
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* is more difficult
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*/
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quotient.part.hi = 0;
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normalized_dividend = dividend;
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normalized_divisor = divisor;
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/* Normalize the operands (shift until the divisor is < 32 bits) */
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do {
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ACPI_SHIFT_RIGHT_64(normalized_divisor.part.hi,
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normalized_divisor.part.lo);
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ACPI_SHIFT_RIGHT_64(normalized_dividend.part.hi,
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normalized_dividend.part.lo);
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} while (normalized_divisor.part.hi != 0);
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/* Partial divide */
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ACPI_DIV_64_BY_32(normalized_dividend.part.hi,
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normalized_dividend.part.lo,
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normalized_divisor.part.lo,
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quotient.part.lo, partial1);
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/*
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* The quotient is always 32 bits, and simply requires adjustment.
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* The 64-bit remainder must be generated.
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*/
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partial1 = quotient.part.lo * divisor.part.hi;
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partial2.full = (u64) quotient.part.lo * divisor.part.lo;
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partial3.full = (u64) partial2.part.hi + partial1;
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remainder.part.hi = partial3.part.lo;
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remainder.part.lo = partial2.part.lo;
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if (partial3.part.hi == 0) {
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if (partial3.part.lo >= dividend.part.hi) {
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if (partial3.part.lo == dividend.part.hi) {
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if (partial2.part.lo > dividend.part.lo) {
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quotient.part.lo--;
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remainder.full -= divisor.full;
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}
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} else {
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quotient.part.lo--;
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remainder.full -= divisor.full;
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}
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}
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remainder.full = remainder.full - dividend.full;
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remainder.part.hi = (u32) - ((s32) remainder.part.hi);
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remainder.part.lo = (u32) - ((s32) remainder.part.lo);
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if (remainder.part.lo) {
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remainder.part.hi--;
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}
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}
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}
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/* Return only what was requested */
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if (out_quotient) {
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*out_quotient = quotient.full;
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}
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if (out_remainder) {
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*out_remainder = remainder.full;
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}
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return_ACPI_STATUS(AE_OK);
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}
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#else
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/*******************************************************************************
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*
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* FUNCTION: acpi_ut_short_divide, acpi_ut_divide
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*
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* PARAMETERS: See function headers above
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*
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* DESCRIPTION: Native versions of the ut_divide functions. Use these if either
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* 1) The target is a 64-bit platform and therefore 64-bit
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* integer math is supported directly by the machine.
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* 2) The target is a 32-bit or 16-bit platform, and the
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* double-precision integer math library is available to
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* perform the divide.
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*
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******************************************************************************/
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acpi_status
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acpi_ut_short_divide(u64 in_dividend,
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u32 divisor, u64 *out_quotient, u32 *out_remainder)
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{
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ACPI_FUNCTION_TRACE(ut_short_divide);
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/* Always check for a zero divisor */
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if (divisor == 0) {
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ACPI_ERROR((AE_INFO, "Divide by zero"));
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return_ACPI_STATUS(AE_AML_DIVIDE_BY_ZERO);
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}
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/* Return only what was requested */
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if (out_quotient) {
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*out_quotient = in_dividend / divisor;
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}
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if (out_remainder) {
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*out_remainder = (u32) (in_dividend % divisor);
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}
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return_ACPI_STATUS(AE_OK);
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}
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acpi_status
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acpi_ut_divide(u64 in_dividend,
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u64 in_divisor, u64 *out_quotient, u64 *out_remainder)
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{
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ACPI_FUNCTION_TRACE(ut_divide);
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/* Always check for a zero divisor */
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if (in_divisor == 0) {
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ACPI_ERROR((AE_INFO, "Divide by zero"));
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return_ACPI_STATUS(AE_AML_DIVIDE_BY_ZERO);
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}
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/* Return only what was requested */
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if (out_quotient) {
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*out_quotient = in_dividend / in_divisor;
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}
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if (out_remainder) {
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*out_remainder = in_dividend % in_divisor;
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}
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return_ACPI_STATUS(AE_OK);
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}
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#endif
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