// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
*
* Module Name: utstrtoul64 - String-to-integer conversion support for both
* 64-bit and 32-bit integers
*
******************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#define _COMPONENT ACPI_UTILITIES
ACPI_MODULE_NAME("utstrtoul64")
/*******************************************************************************
*
* This module contains the top-level string to 64/32-bit unsigned integer
* conversion functions:
*
* 1) A standard strtoul() function that supports 64-bit integers, base
* 8/10/16, with integer overflow support. This is used mainly by the
* iASL compiler, which implements tighter constraints on integer
* constants than the runtime (interpreter) integer-to-string conversions.
* 2) Runtime "Explicit conversion" as defined in the ACPI specification.
* 3) Runtime "Implicit conversion" as defined in the ACPI specification.
*
* Current users of this module:
*
* iASL - Preprocessor (constants and math expressions)
* iASL - Main parser, conversion of constants to integers
* iASL - Data Table Compiler parser (constants and math expressions)
* interpreter - Implicit and explicit conversions, GPE method names
* interpreter - Repair code for return values from predefined names
* debugger - Command line input string conversion
* acpi_dump - ACPI table physical addresses
* acpi_exec - Support for namespace overrides
*
* Notes concerning users of these interfaces:
*
* acpi_gbl_integer_byte_width is used to set the 32/64 bit limit for explicit
* and implicit conversions. This global must be set to the proper width.
* For the core ACPICA code, the width depends on the DSDT version. For the
* acpi_ut_strtoul64 interface, all conversions are 64 bits. This interface is
* used primarily for iASL, where the default width is 64 bits for all parsers,
* but error checking is performed later to flag cases where a 64-bit constant
* is wrongly defined in a 32-bit DSDT/SSDT.
*
* In ACPI, the only place where octal numbers are supported is within
* the ASL language itself. This is implemented via the main acpi_ut_strtoul64
* interface. According the ACPI specification, there is no ACPI runtime
* support (explicit/implicit) for octal string conversions.
*
******************************************************************************/
/*******************************************************************************
*
* FUNCTION: acpi_ut_strtoul64
*
* PARAMETERS: string - Null terminated input string,
* must be a valid pointer
* return_value - Where the converted integer is
* returned. Must be a valid pointer
*
* RETURN: Status and converted integer. Returns an exception on a
* 64-bit numeric overflow
*
* DESCRIPTION: Convert a string into an unsigned integer. Always performs a
* full 64-bit conversion, regardless of the current global
* integer width. Supports Decimal, Hex, and Octal strings.
*
* Current users of this function:
*
* iASL - Preprocessor (constants and math expressions)
* iASL - Main ASL parser, conversion of ASL constants to integers
* iASL - Data Table Compiler parser (constants and math expressions)
* interpreter - Repair code for return values from predefined names
* acpi_dump - ACPI table physical addresses
* acpi_exec - Support for namespace overrides
*
******************************************************************************/
acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
{
acpi_status status = AE_OK;
u8 original_bit_width;
u32 base = 10; /* Default is decimal */
ACPI_FUNCTION_TRACE_STR(ut_strtoul64, string);
*return_value = 0;
/* A NULL return string returns a value of zero */
if (*string == 0) {
return_ACPI_STATUS(AE_OK);
}
if (!acpi_ut_remove_whitespace(&string)) {
return_ACPI_STATUS(AE_OK);
}
/*
* 1) Check for a hex constant. A "0x" prefix indicates base 16.
*/
if (acpi_ut_detect_hex_prefix(&string)) {
base = 16;
}
/*
* 2) Check for an octal constant, defined to be a leading zero
* followed by sequence of octal digits (0-7)
*/
else if (acpi_ut_detect_octal_prefix(&string)) {
base = 8;
}
if (!acpi_ut_remove_leading_zeros(&string)) {
return_ACPI_STATUS(AE_OK); /* Return value 0 */
}
/*
* Force a full 64-bit conversion. The caller (usually iASL) must
* check for a 32-bit overflow later as necessary (If current mode
* is 32-bit, meaning a 32-bit DSDT).
*/
original_bit_width = acpi_gbl_integer_bit_width;
acpi_gbl_integer_bit_width = 64;
/*
* Perform the base 8, 10, or 16 conversion. A 64-bit numeric overflow
* will return an exception (to allow iASL to flag the statement).
*/
switch (base) {
case 8:
status = acpi_ut_convert_octal_string(string, return_value);
break;
case 10:
status = acpi_ut_convert_decimal_string(string, return_value);
break;
case 16:
default:
status = acpi_ut_convert_hex_string(string, return_value);
break;
}
/* Only possible exception from above is a 64-bit overflow */
acpi_gbl_integer_bit_width = original_bit_width;
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_implicit_strtoul64
*
* PARAMETERS: string - Null terminated input string,
* must be a valid pointer
*
* RETURN: Converted integer
*
* DESCRIPTION: Perform a 64-bit conversion with restrictions placed upon
* an "implicit conversion" by the ACPI specification. Used by
* many ASL operators that require an integer operand, and support
* an automatic (implicit) conversion from a string operand
* to the final integer operand. The major restriction is that
* only hex strings are supported.
*
* -----------------------------------------------------------------------------
*
* Base is always 16, either with or without the 0x prefix. Decimal and
* Octal strings are not supported, as per the ACPI specification.
*
* Examples (both are hex values):
* Add ("BA98", Arg0, Local0)
* Subtract ("0x12345678", Arg1, Local1)
*
* Conversion rules as extracted from the ACPI specification:
*
* The converted integer is initialized to the value zero.
* The ASCII string is always interpreted as a hexadecimal constant.
*
* 1) According to the ACPI specification, a "0x" prefix is not allowed.
* However, ACPICA allows this as an ACPI extension on general
* principle. (NO ERROR)
*
* 2) The conversion terminates when the size of an integer is reached
* (32 or 64 bits). There are no numeric overflow conditions. (NO ERROR)
*
* 3) The first non-hex character terminates the conversion and returns
* the current accumulated value of the converted integer (NO ERROR).
*
* 4) Conversion of a null (zero-length) string to an integer is
* technically not allowed. However, ACPICA allows this as an ACPI
* extension. The conversion returns the value 0. (NO ERROR)
*
* NOTE: There are no error conditions returned by this function. At
* the minimum, a value of zero is returned.
*
* Current users of this function:
*
* interpreter - All runtime implicit conversions, as per ACPI specification
* iASL - Data Table Compiler parser (constants and math expressions)
*
******************************************************************************/
u64 acpi_ut_implicit_strtoul64(char *string)
{
u64 converted_integer = 0;
ACPI_FUNCTION_TRACE_STR(ut_implicit_strtoul64, string);
if (!acpi_ut_remove_whitespace(&string)) {
return_VALUE(0);
}
/*
* Per the ACPI specification, only hexadecimal is supported for
* implicit conversions, and the "0x" prefix is "not allowed".
* However, allow a "0x" prefix as an ACPI extension.
*/
acpi_ut_remove_hex_prefix(&string);
if (!acpi_ut_remove_leading_zeros(&string)) {
return_VALUE(0);
}
/*
* Ignore overflow as per the ACPI specification. This is implemented by
* ignoring the return status from the conversion function called below.
* On overflow, the input string is simply truncated.
*/
acpi_ut_convert_hex_string(string, &converted_integer);
return_VALUE(converted_integer);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_explicit_strtoul64
*
* PARAMETERS: string - Null terminated input string,
* must be a valid pointer
*
* RETURN: Converted integer
*
* DESCRIPTION: Perform a 64-bit conversion with the restrictions placed upon
* an "explicit conversion" by the ACPI specification. The
* main restriction is that only hex and decimal are supported.
*
* -----------------------------------------------------------------------------
*
* Base is either 10 (default) or 16 (with 0x prefix). Octal (base 8) strings
* are not supported, as per the ACPI specification.
*
* Examples:
* to_integer ("1000") Decimal
* to_integer ("0xABCD") Hex
*
* Conversion rules as extracted from the ACPI specification:
*
* 1) The input string is either a decimal or hexadecimal numeric string.
* A hex value must be prefixed by "0x" or it is interpreted as decimal.
*
* 2) The value must not exceed the maximum of an integer value
* (32 or 64 bits). The ACPI specification states the behavior is
* "unpredictable", so ACPICA matches the behavior of the implicit
* conversion case. There are no numeric overflow conditions. (NO ERROR)
*
* 3) Behavior on the first non-hex character is not defined by the ACPI
* specification (for the to_integer operator), so ACPICA matches the
* behavior of the implicit conversion case. It terminates the
* conversion and returns the current accumulated value of the converted
* integer. (NO ERROR)
*
* 4) Conversion of a null (zero-length) string to an integer is
* technically not allowed. However, ACPICA allows this as an ACPI
* extension. The conversion returns the value 0. (NO ERROR)
*
* NOTE: There are no error conditions returned by this function. At the
* minimum, a value of zero is returned.
*
* Current users of this function:
*
* interpreter - Runtime ASL to_integer operator, as per the ACPI specification
*
******************************************************************************/
u64 acpi_ut_explicit_strtoul64(char *string)
{
u64 converted_integer = 0;
u32 base = 10; /* Default is decimal */
ACPI_FUNCTION_TRACE_STR(ut_explicit_strtoul64, string);
if (!acpi_ut_remove_whitespace(&string)) {
return_VALUE(0);
}
/*
* Only Hex and Decimal are supported, as per the ACPI specification.
* A "0x" prefix indicates hex; otherwise decimal is assumed.
*/
if (acpi_ut_detect_hex_prefix(&string)) {
base = 16;
}
if (!acpi_ut_remove_leading_zeros(&string)) {
return_VALUE(0);
}
/*
* Ignore overflow as per the ACPI specification. This is implemented by
* ignoring the return status from the conversion functions called below.
* On overflow, the input string is simply truncated.
*/
switch (base) {
case 10:
default:
acpi_ut_convert_decimal_string(string, &converted_integer);
break;
case 16:
acpi_ut_convert_hex_string(string, &converted_integer);
break;
}
return_VALUE(converted_integer);
}
Codebase Browser
linux