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Diffstat (limited to 'usr/src/common/acpica/utilities/utmath.c')
| -rw-r--r-- | usr/src/common/acpica/utilities/utmath.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/usr/src/common/acpica/utilities/utmath.c b/usr/src/common/acpica/utilities/utmath.c new file mode 100644 index 0000000000..aa3d762c0d --- /dev/null +++ b/usr/src/common/acpica/utilities/utmath.c @@ -0,0 +1,375 @@ +/******************************************************************************* + * + * Module Name: utmath - Integer math support routines + * + ******************************************************************************/ + +/* + * Copyright (C) 2000 - 2016, Intel Corp. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. Redistributions in binary form must reproduce at minimum a disclaimer + * substantially similar to the "NO WARRANTY" disclaimer below + * ("Disclaimer") and any redistribution must be conditioned upon + * including a substantially similar Disclaimer requirement for further + * binary redistribution. + * 3. Neither the names of the above-listed copyright holders nor the names + * of any contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * NO WARRANTY + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGES. + */ + +#include "acpi.h" +#include "accommon.h" + + +#define _COMPONENT ACPI_UTILITIES + ACPI_MODULE_NAME ("utmath") + +/* + * Optional support for 64-bit double-precision integer divide. This code + * is configurable and is implemented in order to support 32-bit kernel + * environments where a 64-bit double-precision math library is not available. + * + * Support for a more normal 64-bit divide/modulo (with check for a divide- + * by-zero) appears after this optional section of code. + */ +#ifndef ACPI_USE_NATIVE_DIVIDE + +/* Structures used only for 64-bit divide */ + +typedef struct uint64_struct +{ + UINT32 Lo; + UINT32 Hi; + +} UINT64_STRUCT; + +typedef union uint64_overlay +{ + UINT64 Full; + UINT64_STRUCT Part; + +} UINT64_OVERLAY; + + +/******************************************************************************* + * + * FUNCTION: AcpiUtShortDivide + * + * PARAMETERS: Dividend - 64-bit dividend + * Divisor - 32-bit divisor + * OutQuotient - Pointer to where the quotient is returned + * OutRemainder - Pointer to where the remainder is returned + * + * RETURN: Status (Checks for divide-by-zero) + * + * DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits) + * divide and modulo. The result is a 64-bit quotient and a + * 32-bit remainder. + * + ******************************************************************************/ + +ACPI_STATUS +AcpiUtShortDivide ( + UINT64 Dividend, + UINT32 Divisor, + UINT64 *OutQuotient, + UINT32 *OutRemainder) +{ + UINT64_OVERLAY DividendOvl; + UINT64_OVERLAY Quotient; + UINT32 Remainder32; + + + ACPI_FUNCTION_TRACE (UtShortDivide); + + + /* Always check for a zero divisor */ + + if (Divisor == 0) + { + ACPI_ERROR ((AE_INFO, "Divide by zero")); + return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); + } + + DividendOvl.Full = Dividend; + + /* + * The quotient is 64 bits, the remainder is always 32 bits, + * and is generated by the second divide. + */ + ACPI_DIV_64_BY_32 (0, DividendOvl.Part.Hi, Divisor, + Quotient.Part.Hi, Remainder32); + + ACPI_DIV_64_BY_32 (Remainder32, DividendOvl.Part.Lo, Divisor, + Quotient.Part.Lo, Remainder32); + + /* Return only what was requested */ + + if (OutQuotient) + { + *OutQuotient = Quotient.Full; + } + if (OutRemainder) + { + *OutRemainder = Remainder32; + } + + return_ACPI_STATUS (AE_OK); +} + + +/******************************************************************************* + * + * FUNCTION: AcpiUtDivide + * + * PARAMETERS: InDividend - Dividend + * InDivisor - Divisor + * OutQuotient - Pointer to where the quotient is returned + * OutRemainder - Pointer to where the remainder is returned + * + * RETURN: Status (Checks for divide-by-zero) + * + * DESCRIPTION: Perform a divide and modulo. + * + ******************************************************************************/ + +ACPI_STATUS +AcpiUtDivide ( + UINT64 InDividend, + UINT64 InDivisor, + UINT64 *OutQuotient, + UINT64 *OutRemainder) +{ + UINT64_OVERLAY Dividend; + UINT64_OVERLAY Divisor; + UINT64_OVERLAY Quotient; + UINT64_OVERLAY Remainder; + UINT64_OVERLAY NormalizedDividend; + UINT64_OVERLAY NormalizedDivisor; + UINT32 Partial1; + UINT64_OVERLAY Partial2; + UINT64_OVERLAY Partial3; + + + ACPI_FUNCTION_TRACE (UtDivide); + + + /* Always check for a zero divisor */ + + if (InDivisor == 0) + { + ACPI_ERROR ((AE_INFO, "Divide by zero")); + return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); + } + + Divisor.Full = InDivisor; + Dividend.Full = InDividend; + if (Divisor.Part.Hi == 0) + { + /* + * 1) Simplest case is where the divisor is 32 bits, we can + * just do two divides + */ + Remainder.Part.Hi = 0; + + /* + * The quotient is 64 bits, the remainder is always 32 bits, + * and is generated by the second divide. + */ + ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo, + Quotient.Part.Hi, Partial1); + + ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo, + Quotient.Part.Lo, Remainder.Part.Lo); + } + + else + { + /* + * 2) The general case where the divisor is a full 64 bits + * is more difficult + */ + Quotient.Part.Hi = 0; + NormalizedDividend = Dividend; + NormalizedDivisor = Divisor; + + /* Normalize the operands (shift until the divisor is < 32 bits) */ + + do + { + ACPI_SHIFT_RIGHT_64 ( + NormalizedDivisor.Part.Hi, NormalizedDivisor.Part.Lo); + ACPI_SHIFT_RIGHT_64 ( + NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo); + + } while (NormalizedDivisor.Part.Hi != 0); + + /* Partial divide */ + + ACPI_DIV_64_BY_32 ( + NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo, + NormalizedDivisor.Part.Lo, Quotient.Part.Lo, Partial1); + + /* + * The quotient is always 32 bits, and simply requires + * adjustment. The 64-bit remainder must be generated. + */ + Partial1 = Quotient.Part.Lo * Divisor.Part.Hi; + Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo; + Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1; + + Remainder.Part.Hi = Partial3.Part.Lo; + Remainder.Part.Lo = Partial2.Part.Lo; + + if (Partial3.Part.Hi == 0) + { + if (Partial3.Part.Lo >= Dividend.Part.Hi) + { + if (Partial3.Part.Lo == Dividend.Part.Hi) + { + if (Partial2.Part.Lo > Dividend.Part.Lo) + { + Quotient.Part.Lo--; + Remainder.Full -= Divisor.Full; + } + } + else + { + Quotient.Part.Lo--; + Remainder.Full -= Divisor.Full; + } + } + + Remainder.Full = Remainder.Full - Dividend.Full; + Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi); + Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo); + + if (Remainder.Part.Lo) + { + Remainder.Part.Hi--; + } + } + } + + /* Return only what was requested */ + + if (OutQuotient) + { + *OutQuotient = Quotient.Full; + } + if (OutRemainder) + { + *OutRemainder = Remainder.Full; + } + + return_ACPI_STATUS (AE_OK); +} + +#else + +/******************************************************************************* + * + * FUNCTION: AcpiUtShortDivide, AcpiUtDivide + * + * PARAMETERS: See function headers above + * + * DESCRIPTION: Native versions of the UtDivide functions. Use these if either + * 1) The target is a 64-bit platform and therefore 64-bit + * integer math is supported directly by the machine. + * 2) The target is a 32-bit or 16-bit platform, and the + * double-precision integer math library is available to + * perform the divide. + * + ******************************************************************************/ + +ACPI_STATUS +AcpiUtShortDivide ( + UINT64 InDividend, + UINT32 Divisor, + UINT64 *OutQuotient, + UINT32 *OutRemainder) +{ + + ACPI_FUNCTION_TRACE (UtShortDivide); + + + /* Always check for a zero divisor */ + + if (Divisor == 0) + { + ACPI_ERROR ((AE_INFO, "Divide by zero")); + return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); + } + + /* Return only what was requested */ + + if (OutQuotient) + { + *OutQuotient = InDividend / Divisor; + } + if (OutRemainder) + { + *OutRemainder = (UINT32) (InDividend % Divisor); + } + + return_ACPI_STATUS (AE_OK); +} + +ACPI_STATUS +AcpiUtDivide ( + UINT64 InDividend, + UINT64 InDivisor, + UINT64 *OutQuotient, + UINT64 *OutRemainder) +{ + ACPI_FUNCTION_TRACE (UtDivide); + + + /* Always check for a zero divisor */ + + if (InDivisor == 0) + { + ACPI_ERROR ((AE_INFO, "Divide by zero")); + return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); + } + + + /* Return only what was requested */ + + if (OutQuotient) + { + *OutQuotient = InDividend / InDivisor; + } + if (OutRemainder) + { + *OutRemainder = InDividend % InDivisor; + } + + return_ACPI_STATUS (AE_OK); +} + +#endif |