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Diffstat (limited to 'drivers/acpi/acpica/utstrtoul64.c')
| -rw-r--r-- | drivers/acpi/acpica/utstrtoul64.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/utstrtoul64.c b/drivers/acpi/acpica/utstrtoul64.c new file mode 100644 index 0000000000..5fde619a8b --- /dev/null +++ b/drivers/acpi/acpica/utstrtoul64.c @@ -0,0 +1,327 @@ +// 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); +} |