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minix/drivers/acpi/utilities/utmath.c
Tomas Hruby 9560b6dea8 ACPI driver 
- 99% of the code is Intel's ACPICA. The license is compliant with BSD
  and GNU and virtually all systems that use ACPI use this code, For
  instance it is part of the Linux kernel.

- The only minix specific files are

  acpi.c
  osminixxf.c
  platform/acminix.h

  and

  include/minix/acpi.h

- At the moment the driver does not register interrupt hooks which I
  believe is mainly for handling PnP, events like "battery level is
  low" and power management. Should not be difficult to add it if need
  be.

- The interface to the outside world is virtually non-existent except
  a trivial message based service for PCI driver to query which device
  is connected to what IRQ line. This will evolve as more components
  start using this driver. VM, Scheduler and IOMMU are the possible
  users right now.

- because of dependency on a native 64bit (long long, part of c99) it
  is compiled only with a gnu-like compilers which in case of Minix
  includes gcc llvm-gcc and clang
2010-09-02 15:44:04 +00:00

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/*******************************************************************************
*
* Module Name: utmath - Integer math support routines
*
******************************************************************************/
/******************************************************************************
*
* 1. Copyright Notice
*
* Some or all of this work - Copyright (c) 1999 - 2010, Intel Corp.
* All rights reserved.
*
* 2. License
*
* 2.1. This is your license from Intel Corp. under its intellectual property
* rights. You may have additional license terms from the party that provided
* you this software, covering your right to use that party's intellectual
* property rights.
*
* 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
* copy of the source code appearing in this file ("Covered Code") an
* irrevocable, perpetual, worldwide license under Intel's copyrights in the
* base code distributed originally by Intel ("Original Intel Code") to copy,
* make derivatives, distribute, use and display any portion of the Covered
* Code in any form, with the right to sublicense such rights; and
*
* 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
* license (with the right to sublicense), under only those claims of Intel
* patents that are infringed by the Original Intel Code, to make, use, sell,
* offer to sell, and import the Covered Code and derivative works thereof
* solely to the minimum extent necessary to exercise the above copyright
* license, and in no event shall the patent license extend to any additions
* to or modifications of the Original Intel Code. No other license or right
* is granted directly or by implication, estoppel or otherwise;
*
* The above copyright and patent license is granted only if the following
* conditions are met:
*
* 3. Conditions
*
* 3.1. Redistribution of Source with Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification with rights to further distribute source must include
* the above Copyright Notice, the above License, this list of Conditions,
* and the following Disclaimer and Export Compliance provision. In addition,
* Licensee must cause all Covered Code to which Licensee contributes to
* contain a file documenting the changes Licensee made to create that Covered
* Code and the date of any change. Licensee must include in that file the
* documentation of any changes made by any predecessor Licensee. Licensee
* must include a prominent statement that the modification is derived,
* directly or indirectly, from Original Intel Code.
*
* 3.2. Redistribution of Source with no Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification without rights to further distribute source must
* include the following Disclaimer and Export Compliance provision in the
* documentation and/or other materials provided with distribution. In
* addition, Licensee may not authorize further sublicense of source of any
* portion of the Covered Code, and must include terms to the effect that the
* license from Licensee to its licensee is limited to the intellectual
* property embodied in the software Licensee provides to its licensee, and
* not to intellectual property embodied in modifications its licensee may
* make.
*
* 3.3. Redistribution of Executable. Redistribution in executable form of any
* substantial portion of the Covered Code or modification must reproduce the
* above Copyright Notice, and the following Disclaimer and Export Compliance
* provision in the documentation and/or other materials provided with the
* distribution.
*
* 3.4. Intel retains all right, title, and interest in and to the Original
* Intel Code.
*
* 3.5. Neither the name Intel nor any other trademark owned or controlled by
* Intel shall be used in advertising or otherwise to promote the sale, use or
* other dealings in products derived from or relating to the Covered Code
* without prior written authorization from Intel.
*
* 4. Disclaimer and Export Compliance
*
* 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
* HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
* IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
* INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
* UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
* IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
* PARTICULAR PURPOSE.
*
* 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
* OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
* COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
* SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
* CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
* HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
* SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
* LIMITED REMEDY.
*
* 4.3. Licensee shall not export, either directly or indirectly, any of this
* software or system incorporating such software without first obtaining any
* required license or other approval from the U. S. Department of Commerce or
* any other agency or department of the United States Government. In the
* event Licensee exports any such software from the United States or
* re-exports any such software from a foreign destination, Licensee shall
* ensure that the distribution and export/re-export of the software is in
* compliance with all laws, regulations, orders, or other restrictions of the
* U.S. Export Administration Regulations. Licensee agrees that neither it nor
* any of its subsidiaries will export/re-export any technical data, process,
* software, or service, directly or indirectly, to any country for which the
* United States government or any agency thereof requires an export license,
* other governmental approval, or letter of assurance, without first obtaining
* such license, approval or letter.
*
*****************************************************************************/
#define __UTMATH_C__
#include "acpi.h"
#include "accommon.h"
#define _COMPONENT ACPI_UTILITIES
ACPI_MODULE_NAME ("utmath")
/*
* Support for double-precision integer divide. This code is included here
* in order to support kernel environments where the double-precision math
* library is not available.
*/
#ifndef ACPI_USE_NATIVE_DIVIDE
/*******************************************************************************
*
* 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
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