zephyr/include/misc/util.h

138 lines
3.4 KiB
C

/*
* Copyright (c) 2011-2014, Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @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)
#ifdef __cplusplus
}
#endif
#endif /* _UTIL__H_ */