diff options
Diffstat (limited to 'drivers/acpi/acpica/utstrsuppt.c')
-rw-r--r-- | drivers/acpi/acpica/utstrsuppt.c | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/utstrsuppt.c b/drivers/acpi/acpica/utstrsuppt.c new file mode 100644 index 000000000..05ff20049 --- /dev/null +++ b/drivers/acpi/acpica/utstrsuppt.c @@ -0,0 +1,428 @@ +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 +/******************************************************************************* + * + * Module Name: utstrsuppt - Support functions for string-to-integer conversion + * + ******************************************************************************/ + +#include <acpi/acpi.h> +#include "accommon.h" + +#define _COMPONENT ACPI_UTILITIES +ACPI_MODULE_NAME("utstrsuppt") + +/* Local prototypes */ +static acpi_status +acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit); + +static acpi_status +acpi_ut_strtoul_multiply64(u64 multiplicand, u32 base, u64 *out_product); + +static acpi_status acpi_ut_strtoul_add64(u64 addend1, u32 digit, u64 *out_sum); + +/******************************************************************************* + * + * FUNCTION: acpi_ut_convert_octal_string + * + * PARAMETERS: string - Null terminated input string + * return_value_ptr - Where the converted value is returned + * + * RETURN: Status and 64-bit converted integer + * + * DESCRIPTION: Performs a base 8 conversion of the input string to an + * integer value, either 32 or 64 bits. + * + * NOTE: Maximum 64-bit unsigned octal value is 01777777777777777777777 + * Maximum 32-bit unsigned octal value is 037777777777 + * + ******************************************************************************/ + +acpi_status acpi_ut_convert_octal_string(char *string, u64 *return_value_ptr) +{ + u64 accumulated_value = 0; + acpi_status status = AE_OK; + + /* Convert each ASCII byte in the input string */ + + while (*string) { + + /* Character must be ASCII 0-7, otherwise terminate with no error */ + + if (!(ACPI_IS_OCTAL_DIGIT(*string))) { + break; + } + + /* Convert and insert this octal digit into the accumulator */ + + status = acpi_ut_insert_digit(&accumulated_value, 8, *string); + if (ACPI_FAILURE(status)) { + status = AE_OCTAL_OVERFLOW; + break; + } + + string++; + } + + /* Always return the value that has been accumulated */ + + *return_value_ptr = accumulated_value; + return (status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_convert_decimal_string + * + * PARAMETERS: string - Null terminated input string + * return_value_ptr - Where the converted value is returned + * + * RETURN: Status and 64-bit converted integer + * + * DESCRIPTION: Performs a base 10 conversion of the input string to an + * integer value, either 32 or 64 bits. + * + * NOTE: Maximum 64-bit unsigned decimal value is 18446744073709551615 + * Maximum 32-bit unsigned decimal value is 4294967295 + * + ******************************************************************************/ + +acpi_status acpi_ut_convert_decimal_string(char *string, u64 *return_value_ptr) +{ + u64 accumulated_value = 0; + acpi_status status = AE_OK; + + /* Convert each ASCII byte in the input string */ + + while (*string) { + + /* Character must be ASCII 0-9, otherwise terminate with no error */ + + if (!isdigit(*string)) { + break; + } + + /* Convert and insert this decimal digit into the accumulator */ + + status = acpi_ut_insert_digit(&accumulated_value, 10, *string); + if (ACPI_FAILURE(status)) { + status = AE_DECIMAL_OVERFLOW; + break; + } + + string++; + } + + /* Always return the value that has been accumulated */ + + *return_value_ptr = accumulated_value; + return (status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_convert_hex_string + * + * PARAMETERS: string - Null terminated input string + * return_value_ptr - Where the converted value is returned + * + * RETURN: Status and 64-bit converted integer + * + * DESCRIPTION: Performs a base 16 conversion of the input string to an + * integer value, either 32 or 64 bits. + * + * NOTE: Maximum 64-bit unsigned hex value is 0xFFFFFFFFFFFFFFFF + * Maximum 32-bit unsigned hex value is 0xFFFFFFFF + * + ******************************************************************************/ + +acpi_status acpi_ut_convert_hex_string(char *string, u64 *return_value_ptr) +{ + u64 accumulated_value = 0; + acpi_status status = AE_OK; + + /* Convert each ASCII byte in the input string */ + + while (*string) { + + /* Must be ASCII A-F, a-f, or 0-9, otherwise terminate with no error */ + + if (!isxdigit(*string)) { + break; + } + + /* Convert and insert this hex digit into the accumulator */ + + status = acpi_ut_insert_digit(&accumulated_value, 16, *string); + if (ACPI_FAILURE(status)) { + status = AE_HEX_OVERFLOW; + break; + } + + string++; + } + + /* Always return the value that has been accumulated */ + + *return_value_ptr = accumulated_value; + return (status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_remove_leading_zeros + * + * PARAMETERS: string - Pointer to input ASCII string + * + * RETURN: Next character after any leading zeros. This character may be + * used by the caller to detect end-of-string. + * + * DESCRIPTION: Remove any leading zeros in the input string. Return the + * next character after the final ASCII zero to enable the caller + * to check for the end of the string (NULL terminator). + * + ******************************************************************************/ + +char acpi_ut_remove_leading_zeros(char **string) +{ + + while (**string == ACPI_ASCII_ZERO) { + *string += 1; + } + + return (**string); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_remove_whitespace + * + * PARAMETERS: string - Pointer to input ASCII string + * + * RETURN: Next character after any whitespace. This character may be + * used by the caller to detect end-of-string. + * + * DESCRIPTION: Remove any leading whitespace in the input string. Return the + * next character after the final ASCII zero to enable the caller + * to check for the end of the string (NULL terminator). + * + ******************************************************************************/ + +char acpi_ut_remove_whitespace(char **string) +{ + + while (isspace((u8)**string)) { + *string += 1; + } + + return (**string); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_detect_hex_prefix + * + * PARAMETERS: string - Pointer to input ASCII string + * + * RETURN: TRUE if a "0x" prefix was found at the start of the string + * + * DESCRIPTION: Detect and remove a hex "0x" prefix + * + ******************************************************************************/ + +u8 acpi_ut_detect_hex_prefix(char **string) +{ + char *initial_position = *string; + + acpi_ut_remove_hex_prefix(string); + if (*string != initial_position) { + return (TRUE); /* String is past leading 0x */ + } + + return (FALSE); /* Not a hex string */ +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_remove_hex_prefix + * + * PARAMETERS: string - Pointer to input ASCII string + * + * RETURN: none + * + * DESCRIPTION: Remove a hex "0x" prefix + * + ******************************************************************************/ + +void acpi_ut_remove_hex_prefix(char **string) +{ + if ((**string == ACPI_ASCII_ZERO) && + (tolower((int)*(*string + 1)) == 'x')) { + *string += 2; /* Go past the leading 0x */ + } +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_detect_octal_prefix + * + * PARAMETERS: string - Pointer to input ASCII string + * + * RETURN: True if an octal "0" prefix was found at the start of the + * string + * + * DESCRIPTION: Detect and remove an octal prefix (zero) + * + ******************************************************************************/ + +u8 acpi_ut_detect_octal_prefix(char **string) +{ + + if (**string == ACPI_ASCII_ZERO) { + *string += 1; /* Go past the leading 0 */ + return (TRUE); + } + + return (FALSE); /* Not an octal string */ +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_insert_digit + * + * PARAMETERS: accumulated_value - Current value of the integer value + * accumulator. The new value is + * returned here. + * base - Radix, either 8/10/16 + * ascii_digit - ASCII single digit to be inserted + * + * RETURN: Status and result of the convert/insert operation. The only + * possible returned exception code is numeric overflow of + * either the multiply or add conversion operations. + * + * DESCRIPTION: Generic conversion and insertion function for all bases: + * + * 1) Multiply the current accumulated/converted value by the + * base in order to make room for the new character. + * + * 2) Convert the new character to binary and add it to the + * current accumulated value. + * + * Note: The only possible exception indicates an integer + * overflow (AE_NUMERIC_OVERFLOW) + * + ******************************************************************************/ + +static acpi_status +acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit) +{ + acpi_status status; + u64 product; + + /* Make room in the accumulated value for the incoming digit */ + + status = acpi_ut_strtoul_multiply64(*accumulated_value, base, &product); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* Add in the new digit, and store the sum to the accumulated value */ + + status = + acpi_ut_strtoul_add64(product, + acpi_ut_ascii_char_to_hex(ascii_digit), + accumulated_value); + + return (status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_strtoul_multiply64 + * + * PARAMETERS: multiplicand - Current accumulated converted integer + * base - Base/Radix + * out_product - Where the product is returned + * + * RETURN: Status and 64-bit product + * + * DESCRIPTION: Multiply two 64-bit values, with checking for 64-bit overflow as + * well as 32-bit overflow if necessary (if the current global + * integer width is 32). + * + ******************************************************************************/ + +static acpi_status +acpi_ut_strtoul_multiply64(u64 multiplicand, u32 base, u64 *out_product) +{ + u64 product; + u64 quotient; + + /* Exit if either operand is zero */ + + *out_product = 0; + if (!multiplicand || !base) { + return (AE_OK); + } + + /* + * Check for 64-bit overflow before the actual multiplication. + * + * Notes: 64-bit division is often not supported on 32-bit platforms + * (it requires a library function), Therefore ACPICA has a local + * 64-bit divide function. Also, Multiplier is currently only used + * as the radix (8/10/16), to the 64/32 divide will always work. + */ + acpi_ut_short_divide(ACPI_UINT64_MAX, base, "ient, NULL); + if (multiplicand > quotient) { + return (AE_NUMERIC_OVERFLOW); + } + + product = multiplicand * base; + + /* Check for 32-bit overflow if necessary */ + + if ((acpi_gbl_integer_bit_width == 32) && (product > ACPI_UINT32_MAX)) { + return (AE_NUMERIC_OVERFLOW); + } + + *out_product = product; + return (AE_OK); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ut_strtoul_add64 + * + * PARAMETERS: addend1 - Current accumulated converted integer + * digit - New hex value/char + * out_sum - Where sum is returned (Accumulator) + * + * RETURN: Status and 64-bit sum + * + * DESCRIPTION: Add two 64-bit values, with checking for 64-bit overflow as + * well as 32-bit overflow if necessary (if the current global + * integer width is 32). + * + ******************************************************************************/ + +static acpi_status acpi_ut_strtoul_add64(u64 addend1, u32 digit, u64 *out_sum) +{ + u64 sum; + + /* Check for 64-bit overflow before the actual addition */ + + if ((addend1 > 0) && (digit > (ACPI_UINT64_MAX - addend1))) { + return (AE_NUMERIC_OVERFLOW); + } + + sum = addend1 + digit; + + /* Check for 32-bit overflow if necessary */ + + if ((acpi_gbl_integer_bit_width == 32) && (sum > ACPI_UINT32_MAX)) { + return (AE_NUMERIC_OVERFLOW); + } + + *out_sum = sum; + return (AE_OK); +} |