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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 _UTIL__H_
#define _UTIL__H_
#ifdef __cplusplus
extern "C" {
#endif
#ifndef _ASMLANGUAGE
#include <stdint.h>
/* Helper to pass a int as a pointer or vice-versa.
* Those are available for 32 bits architectures:
*/
#define POINTER_TO_UINT(x) ((uint32_t) (x))
#define UINT_TO_POINTER(x) ((void *) (x))
#define POINTER_TO_INT(x) ((int32_t) (x))
#define INT_TO_POINTER(x) ((void *) (x))
/* Evaluates to 0 if cond is true-ish; compile error otherwise */
#define ZERO_OR_COMPILE_ERROR(cond) ((int) sizeof(char[1 - 2 * !(cond)]) - 1)
/* Evaluates to 0 if array is an array; compile error if not array (e.g.
* pointer)
*/
#define IS_ARRAY(array) \
ZERO_OR_COMPILE_ERROR( \
!__builtin_types_compatible_p(__typeof__(array), \
__typeof__(&(array)[0])))
/* Evaluates to number of elements in an array; compile error if not
* an array (e.g. pointer)
*/
#define ARRAY_SIZE(array) \
((unsigned long) (IS_ARRAY(array) + \
(sizeof(array) / sizeof((array)[0]))))
/* Evaluates to 1 if ptr is part of array, 0 otherwise; compile error if
* "array" argument is not an array (e.g. "ptr" and "array" mixed up)
*/
#define PART_OF_ARRAY(array, ptr) \
((ptr) && ((ptr) >= &array[0] && (ptr) < &array[ARRAY_SIZE(array)]))
#define CONTAINER_OF(ptr, type, field) \
((type *)(((char *)(ptr)) - offsetof(type, field)))
/* round "x" up/down to next multiple of "align" (which must be a power of 2) */
#define ROUND_UP(x, align) \
(((unsigned long)(x) + ((unsigned long)align - 1)) & \
~((unsigned long)align - 1))
#define ROUND_DOWN(x, align) ((unsigned long)(x) & ~((unsigned long)align - 1))
#define ceiling_fraction(numerator, divider) \
(((numerator) + ((divider) - 1)) / (divider))
#ifdef INLINED
#define INLINE inline
#else
#define INLINE
#endif
#ifndef max
#define max(a, b) (((a) > (b)) ? (a) : (b))
#endif
#ifndef min
#define min(a, b) (((a) < (b)) ? (a) : (b))
#endif
static inline int is_power_of_two(unsigned int x)
{
return (x != 0) && !(x & (x - 1));
}
static inline int64_t arithmetic_shift_right(int64_t value, uint8_t shift)
{
int64_t sign_ext;
if (shift == 0) {
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));
}
#endif /* !_ASMLANGUAGE */
/* KB, MB, GB */
#define KB(x) ((x) << 10)
#define MB(x) (KB(x) << 10)
#define GB(x) (MB(x) << 10)
/* KHZ, MHZ */
#define KHZ(x) ((x) * 1000)
#define MHZ(x) (KHZ(x) * 1000)
#ifndef BIT
#define BIT(n) (1UL << (n))
#endif
#define BIT_MASK(n) (BIT(n) - 1)
/**
* @brief Check for macro definition in compiler-visible expressions
*
* This trick was pioneered in Linux as the config_enabled() macro.
* The madness has the effect of taking a macro value that may be
* defined to "1" (e.g. CONFIG_MYFEATURE), or may not be defined at
* all and turning it into a literal expression that can be used at
* "runtime". That is, it works similarly to
* "defined(CONFIG_MYFEATURE)" does except that it is an expansion
* that can exist in a standard expression and be seen by the compiler
* and optimizer. Thus much ifdef usage can be replaced with cleaner
* expressions like:
*
* if (IS_ENABLED(CONFIG_MYFEATURE))
* myfeature_enable();
*
* INTERNAL
* First pass just to expand any existing macros, we need the macro
* value to be e.g. a literal "1" at expansion time in the next macro,
* not "(1)", etc... Standard recursive expansion does not work.
*/
#define IS_ENABLED(config_macro) _IS_ENABLED1(config_macro)
/* Now stick on a "_XXXX" prefix, it will now be "_XXXX1" if config_macro
* is "1", or just "_XXXX" if it's undefined.
* ENABLED: _IS_ENABLED2(_XXXX1)
* DISABLED _IS_ENABLED2(_XXXX)
*/
#define _IS_ENABLED1(config_macro) _IS_ENABLED2(_XXXX##config_macro)
/* Here's the core trick, we map "_XXXX1" to "_YYYY," (i.e. a string
* with a trailing comma), so it has the effect of making this a
* two-argument tuple to the preprocessor only in the case where the
* value is defined to "1"
* ENABLED: _YYYY, <--- note comma!
* DISABLED: _XXXX
*/
#define _XXXX1 _YYYY,
/* Then we append an extra argument to fool the gcc preprocessor into
* accepting it as a varargs macro.
* arg1 arg2 arg3
* ENABLED: _IS_ENABLED3(_YYYY, 1, 0)
* DISABLED _IS_ENABLED3(_XXXX 1, 0)
*/
#define _IS_ENABLED2(one_or_two_args) _IS_ENABLED3(one_or_two_args 1, 0)
/* And our second argument is thus now cooked to be 1 in the case
* where the value is defined to 1, and 0 if not:
*/
#define _IS_ENABLED3(ignore_this, val, ...) val
#ifdef __cplusplus
}
#endif
#endif /* _UTIL__H_ */