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/*
* Copyright (c) 2011-2014, Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Misc utilities
*
* Misc utilities usable by the kernel and application code.
*/
#ifndef ZEPHYR_INCLUDE_SYS_UTIL_H_
#define ZEPHYR_INCLUDE_SYS_UTIL_H_
#include <sys/util_macro.h>
/* needs to be outside _ASMLANGUAGE so 'true' and 'false' can turn
* into '1' and '0' for asm or linker scripts
*/
#include <stdbool.h>
#ifndef _ASMLANGUAGE
#include <zephyr/types.h>
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup sys-util Utility Functions
* @{
*/
/** @brief Cast @p x, a pointer, to an unsigned integer. */
#define POINTER_TO_UINT(x) ((uintptr_t) (x))
/** @brief Cast @p x, an unsigned integer, to a <tt>void*</tt>. */
#define UINT_TO_POINTER(x) ((void *) (uintptr_t) (x))
/** @brief Cast @p x, a pointer, to a signed integer. */
#define POINTER_TO_INT(x) ((intptr_t) (x))
/** @brief Cast @p x, a signed integer, to a <tt>void*</tt>. */
#define INT_TO_POINTER(x) ((void *) (intptr_t) (x))
#if !(defined(__CHAR_BIT__) && defined(__SIZEOF_LONG__))
# error Missing required predefined macros for BITS_PER_LONG calculation
#endif
/** Number of bits in a long int. */
#define BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
/**
* @brief Create a contiguous bitmask starting at bit position @p l
* and ending at position @p h.
*/
#define GENMASK(h, l) \
(((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
/** @brief 0 if @p cond is true-ish; causes a compile error otherwise. */
#define ZERO_OR_COMPILE_ERROR(cond) ((int) sizeof(char[1 - 2 * !(cond)]) - 1)
#if defined(__cplusplus)
/* The built-in function used below for type checking in C is not
* supported by GNU C++.
*/
#define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))
#else /* __cplusplus */
/**
* @brief Zero if @p array has an array type, a compile error otherwise
*
* This macro is available only from C, not C++.
*/
#define IS_ARRAY(array) \
ZERO_OR_COMPILE_ERROR( \
!__builtin_types_compatible_p(__typeof__(array), \
__typeof__(&(array)[0])))
/**
* @brief Number of elements in the given @p array
*
* In C++, due to language limitations, this will accept as @p array
* any type that implements <tt>operator[]</tt>. The results may not be
* particulary meaningful in this case.
*
* In C, passing a pointer as @p array causes a compile error.
*/
#define ARRAY_SIZE(array) \
((long) (IS_ARRAY(array) + (sizeof(array) / sizeof((array)[0]))))
#endif /* __cplusplus */
/**
* @brief Check if a pointer @p ptr lies within @p array.
*
* In C but not C++, this causes a compile error if @p array is not an array
* (e.g. if @p ptr and @p array are mixed up).
*
* @param ptr a pointer
* @param array an array
* @return 1 if @p ptr is part of @p array, 0 otherwise
*/
#define PART_OF_ARRAY(array, ptr) \
((ptr) && ((ptr) >= &array[0] && (ptr) < &array[ARRAY_SIZE(array)]))
/**
* @brief Get a pointer to a container structure from an element
*
* Example:
*
* struct foo {
* int bar;
* };
*
* struct foo my_foo;
* int *ptr = &my_foo.bar;
*
* struct foo *container = CONTAINER_OF(ptr, struct foo, bar);
*
* Above, @p container points at @p my_foo.
*
* @param ptr pointer to a structure element
* @param type name of the type that @p ptr is an element of
* @param field the name of the field within the struct @p ptr points to
* @return a pointer to the structure that contains @p ptr
*/
#define CONTAINER_OF(ptr, type, field) \
((type *)(((char *)(ptr)) - offsetof(type, field)))
/**
* @brief Value of @p x rounded up to the next multiple of @p align,
* which must be a power of 2.
*/
#define ROUND_UP(x, align) \
(((unsigned long)(x) + ((unsigned long)(align) - 1)) & \
~((unsigned long)(align) - 1))
/**
* @brief Value of @p x rounded down to the previous multiple of @p
* align, which must be a power of 2.
*/
#define ROUND_DOWN(x, align) \
((unsigned long)(x) & ~((unsigned long)(align) - 1))
/** @brief Value of @p x rounded up to the next word boundary. */
#define WB_UP(x) ROUND_UP(x, sizeof(void *))
/** @brief Value of @p x rounded down to the previous word boundary. */
#define WB_DN(x) ROUND_DOWN(x, sizeof(void *))
/**
* @brief Ceiling function applied to @p numerator / @p divider as a fraction.
*/
#define ceiling_fraction(numerator, divider) \
(((numerator) + ((divider) - 1)) / (divider))
/**
* @def MAX
* @brief The larger value between @p a and @p b.
* @note Arguments are evaluated twice.
*/
#ifndef MAX
/* Use Z_MAX for a GCC-only, single evaluation version */
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#endif
/**
* @def MIN
* @brief The smaller value between @p a and @p b.
* @note Arguments are evaluated twice.
*/
#ifndef MIN
/* Use Z_MIN for a GCC-only, single evaluation version */
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif
/**
* @def CLAMP
* @brief Clamp a value to a given range.
* @note Arguments are evaluated multiple times.
*/
#ifndef CLAMP
/* Use Z_CLAMP for a GCC-only, single evaluation version */
#define CLAMP(val, low, high) (((val) <= (low)) ? (low) : MIN(val, high))
#endif
/**
* @brief Is @p x a power of two?
* @param x value to check
* @return true if @p x is a power of two, false otherwise
*/
static inline bool is_power_of_two(unsigned int x)
{
return (x != 0U) && ((x & (x - 1U)) == 0U);
}
/**
* @brief Arithmetic shift right
* @param value value to shift
* @param shift number of bits to shift
* @return @p value shifted right by @p shift; opened bit positions are
* filled with the sign bit
*/
static inline int64_t arithmetic_shift_right(int64_t value, uint8_t shift)
{
int64_t sign_ext;
if (shift == 0U) {
return value;
}
/* extract sign bit */
sign_ext = (value >> 63) & 1;
/* make all bits of sign_ext be the same as the value's sign bit */
sign_ext = -sign_ext;
/* shift value and fill opened bit positions with sign bit */
return (value >> shift) | (sign_ext << (64 - shift));
}
/**
* @brief byte by byte memcpy.
*
* Copy `size` bytes of `src` into `dest`. This is guaranteed to be done byte by byte.
*
* @param dst Pointer to the destination memory.
* @param src Pointer to the source of the data.
* @param size The number of bytes to copy.
*/
static inline void bytecpy(void *dst, const void *src, size_t size)
{
size_t i;
for (i = 0; i < size; ++i) {
((uint8_t *)dst)[i] = ((uint8_t *)src)[i];
}
}
/**
* @brief Convert a single character into a hexadecimal nibble.
*
* @param c The character to convert
* @param x The address of storage for the converted number.
*
* @return Zero on success or (negative) error code otherwise.
*/
int char2hex(char c, uint8_t *x);
/**
* @brief Convert a single hexadecimal nibble into a character.
*
* @param c The number to convert
* @param x The address of storage for the converted character.
*
* @return Zero on success or (negative) error code otherwise.
*/
int hex2char(uint8_t x, char *c);
/**
* @brief Convert a binary array into string representation.
*
* @param buf The binary array to convert
* @param buflen The length of the binary array to convert
* @param hex Address of where to store the string representation.
* @param hexlen Size of the storage area for string representation.
*
* @return The length of the converted string, or 0 if an error occurred.
*/
size_t bin2hex(const uint8_t *buf, size_t buflen, char *hex, size_t hexlen);
/**
* @brief Convert a hexadecimal string into a binary array.
*
* @param hex The hexadecimal string to convert
* @param hexlen The length of the hexadecimal string to convert.
* @param buf Address of where to store the binary data
* @param buflen Size of the storage area for binary data
*
* @return The length of the binary array, or 0 if an error occurred.
*/
size_t hex2bin(const char *hex, size_t hexlen, uint8_t *buf, size_t buflen);
/**
* @brief Convert a binary coded decimal (BCD 8421) value to binary.
*
* @param bcd BCD 8421 value to convert.
*
* @return Binary representation of input value.
*/
static inline uint8_t bcd2bin(uint8_t bcd)
{
return ((10 * (bcd >> 4)) + (bcd & 0x0F));
}
/**
* @brief Convert a binary value to binary coded decimal (BCD 8421).
*
* @param bin Binary value to convert.
*
* @return BCD 8421 representation of input value.
*/
static inline uint8_t bin2bcd(uint8_t bin)
{
return (((bin / 10) << 4) | (bin % 10));
}
/**
* @brief Convert a uint8_t into a decimal string representation.
*
* Convert a uint8_t value into its ASCII decimal string representation.
* The string is terminated if there is enough space in buf.
*
* @param buf Address of where to store the string representation.
* @param buflen Size of the storage area for string representation.
* @param value The value to convert to decimal string
*
* @return The length of the converted string (excluding terminator if
* any), or 0 if an error occurred.
*/
uint8_t u8_to_dec(char *buf, uint8_t buflen, uint8_t value);
#ifdef __cplusplus
}
#endif
#endif /* !_ASMLANGUAGE */
/** @brief Number of bytes in @p x kibibytes */
#ifdef _LINKER
/* This is used in linker scripts so need to avoid type casting there */
#define KB(x) ((x) << 10)
#else
#define KB(x) (((size_t)x) << 10)
#endif
/** @brief Number of bytes in @p x mebibytes */
#define MB(x) (KB(x) << 10)
/** @brief Number of bytes in @p x gibibytes */
#define GB(x) (MB(x) << 10)
/** @brief Number of Hz in @p x kHz */
#define KHZ(x) ((x) * 1000)
/** @brief Number of Hz in @p x MHz */
#define MHZ(x) (KHZ(x) * 1000)
/**
* @}
*/
#endif /* ZEPHYR_INCLUDE_SYS_UTIL_H_ */