linux/drivers/acpi/utilities/utmath.c
Robert Moore 44f6c01242 ACPICA 20050408 from Bob Moore
Fixed three cases in the interpreter where an "index"
argument to an ASL function was still (internally) 32
bits instead of the required 64 bits.  This was the Index
argument to the Index, Mid, and Match operators.

The "strupr" function is now permanently local
(acpi_ut_strupr), since this is not a POSIX-defined
function and not present in most kernel-level C
libraries. References to the C library strupr function
have been removed from the headers.

Completed the deployment of static
functions/prototypes. All prototypes with the static
attribute have been moved from the headers to the owning
C file.

ACPICA 20050329 from Bob Moore

An error is now generated if an attempt is made to create
a Buffer Field of length zero (A CreateField with a length
operand of zero.)

The interpreter now issues a warning whenever executable
code at the module level is detected during ACPI table
load. This will give some idea of the prevalence of this
type of code.

Implemented support for references to named objects (other
than control methods) within package objects.

Enhanced package object output for the debug
object. Package objects are now completely dumped, showing
all elements.

Enhanced miscellaneous object output for the debug
object. Any object can now be written to the debug object
(for example, a device object can be written, and the type
of the object will be displayed.)

The "static" qualifier has been added to all local
functions across the core subsystem.

The number of "long" lines (> 80 chars) within the source
has been significantly reduced, by about 1/3.

Cleaned up all header files to ensure that all CA/iASL
functions are prototyped (even static functions) and the
formatting is consistent.

Two new header files have been added, acopcode.h and
acnames.h.

Removed several obsolete functions that were no longer
used.

Signed-off-by: Len Brown <len.brown@intel.com>
2005-07-12 00:08:52 -04:00

336 lines
9.8 KiB
C

/*******************************************************************************
*
* Module Name: utmath - Integer math support routines
*
******************************************************************************/
/*
* Copyright (C) 2000 - 2005, R. Byron Moore
* 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/acpi.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: acpi_ut_short_divide
*
* PARAMETERS: Dividend - 64-bit dividend
* Divisor - 32-bit divisor
* out_quotient - Pointer to where the quotient is returned
* out_remainder - 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
acpi_ut_short_divide (
acpi_integer dividend,
u32 divisor,
acpi_integer *out_quotient,
u32 *out_remainder)
{
union uint64_overlay dividend_ovl;
union uint64_overlay quotient;
u32 remainder32;
ACPI_FUNCTION_TRACE ("ut_short_divide");
/* Always check for a zero divisor */
if (divisor == 0) {
ACPI_REPORT_ERROR (("acpi_ut_short_divide: Divide by zero\n"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
dividend_ovl.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, dividend_ovl.part.hi, divisor,
quotient.part.hi, remainder32);
ACPI_DIV_64_BY_32 (remainder32, dividend_ovl.part.lo, divisor,
quotient.part.lo, remainder32);
/* Return only what was requested */
if (out_quotient) {
*out_quotient = quotient.full;
}
if (out_remainder) {
*out_remainder = remainder32;
}
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_divide
*
* PARAMETERS: in_dividend - Dividend
* in_divisor - Divisor
* out_quotient - Pointer to where the quotient is returned
* out_remainder - Pointer to where the remainder is returned
*
* RETURN: Status (Checks for divide-by-zero)
*
* DESCRIPTION: Perform a divide and modulo.
*
******************************************************************************/
acpi_status
acpi_ut_divide (
acpi_integer in_dividend,
acpi_integer in_divisor,
acpi_integer *out_quotient,
acpi_integer *out_remainder)
{
union uint64_overlay dividend;
union uint64_overlay divisor;
union uint64_overlay quotient;
union uint64_overlay remainder;
union uint64_overlay normalized_dividend;
union uint64_overlay normalized_divisor;
u32 partial1;
union uint64_overlay partial2;
union uint64_overlay partial3;
ACPI_FUNCTION_TRACE ("ut_divide");
/* Always check for a zero divisor */
if (in_divisor == 0) {
ACPI_REPORT_ERROR (("acpi_ut_divide: Divide by zero\n"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
divisor.full = in_divisor;
dividend.full = in_dividend;
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;
normalized_dividend = dividend;
normalized_divisor = divisor;
/* Normalize the operands (shift until the divisor is < 32 bits) */
do {
ACPI_SHIFT_RIGHT_64 (normalized_divisor.part.hi,
normalized_divisor.part.lo);
ACPI_SHIFT_RIGHT_64 (normalized_dividend.part.hi,
normalized_dividend.part.lo);
} while (normalized_divisor.part.hi != 0);
/* Partial divide */
ACPI_DIV_64_BY_32 (normalized_dividend.part.hi,
normalized_dividend.part.lo,
normalized_divisor.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 = (acpi_integer) quotient.part.lo * divisor.part.lo;
partial3.full = (acpi_integer) 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 = (u32) -((s32) remainder.part.hi);
remainder.part.lo = (u32) -((s32) remainder.part.lo);
if (remainder.part.lo) {
remainder.part.hi--;
}
}
}
/* Return only what was requested */
if (out_quotient) {
*out_quotient = quotient.full;
}
if (out_remainder) {
*out_remainder = remainder.full;
}
return_ACPI_STATUS (AE_OK);
}
#else
/*******************************************************************************
*
* FUNCTION: acpi_ut_short_divide, acpi_ut_divide
*
* PARAMETERS: See function headers above
*
* DESCRIPTION: Native versions of the ut_divide 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
acpi_ut_short_divide (
acpi_integer in_dividend,
u32 divisor,
acpi_integer *out_quotient,
u32 *out_remainder)
{
ACPI_FUNCTION_TRACE ("ut_short_divide");
/* Always check for a zero divisor */
if (divisor == 0) {
ACPI_REPORT_ERROR (("acpi_ut_short_divide: Divide by zero\n"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
/* Return only what was requested */
if (out_quotient) {
*out_quotient = in_dividend / divisor;
}
if (out_remainder) {
*out_remainder = (u32) in_dividend % divisor;
}
return_ACPI_STATUS (AE_OK);
}
acpi_status
acpi_ut_divide (
acpi_integer in_dividend,
acpi_integer in_divisor,
acpi_integer *out_quotient,
acpi_integer *out_remainder)
{
ACPI_FUNCTION_TRACE ("ut_divide");
/* Always check for a zero divisor */
if (in_divisor == 0) {
ACPI_REPORT_ERROR (("acpi_ut_divide: Divide by zero\n"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
/* Return only what was requested */
if (out_quotient) {
*out_quotient = in_dividend / in_divisor;
}
if (out_remainder) {
*out_remainder = in_dividend % in_divisor;
}
return_ACPI_STATUS (AE_OK);
}
#endif