bitarray.h

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/*
 * Copyright (c) 2021 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_SYS_BITARRAY_H_
#define ZEPHYR_INCLUDE_SYS_BITARRAY_H_
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <stddef.h>
#include <stdint.h>
 
#include <zephyr/kernel.h>
#include <zephyr/sys/util.h>
 
struct sys_bitarray {
        /* Number of bits */
        uint32_t num_bits;
 
        /* Number of bundles */
        uint32_t num_bundles;
 
        /* Bundle of bits */
        uint32_t *bundles;
 
        /* Spinlock guarding access to this bit array */
        struct k_spinlock lock;
};
typedef struct sys_bitarray sys_bitarray_t;
 
#define _SYS_BITARRAY_DEFINE(name, total_bits, sba_mod)                 \
        sba_mod uint32_t _sys_bitarray_bundles_##name                   \
                [DIV_ROUND_UP(DIV_ROUND_UP(total_bits, 8),              \
                               sizeof(uint32_t))] = {0};                \
        sba_mod sys_bitarray_t name = {                                 \
                .num_bits = total_bits,                                 \
                .num_bundles = DIV_ROUND_UP(                            \
                        DIV_ROUND_UP(total_bits, 8), sizeof(uint32_t)), \
                .bundles = _sys_bitarray_bundles_##name,                \
        }
 
#define SYS_BITARRAY_DEFINE(name, total_bits)                           \
        _SYS_BITARRAY_DEFINE(name, total_bits,)
 
#define SYS_BITARRAY_DEFINE_STATIC(name, total_bits)                    \
        _SYS_BITARRAY_DEFINE(name, total_bits, static)
 
int sys_bitarray_set_bit(sys_bitarray_t *bitarray, size_t bit);
 
int sys_bitarray_clear_bit(sys_bitarray_t *bitarray, size_t bit);
 
int sys_bitarray_test_bit(sys_bitarray_t *bitarray, size_t bit, int *val);
 
int sys_bitarray_test_and_set_bit(sys_bitarray_t *bitarray, size_t bit, int *prev_val);
 
int sys_bitarray_test_and_clear_bit(sys_bitarray_t *bitarray, size_t bit, int *prev_val);
 
int sys_bitarray_alloc(sys_bitarray_t *bitarray, size_t num_bits,
                       size_t *offset);
 
/*
 * Calculates the bit-wise XOR of two bitarrays in a region.
 * The result is stored in the first bitarray passed in (@p dst).
 * Both bitarrays must be of the same size.
 *
 * @param dst      Bitarray struct
 * @param other    Bitarray struct
 * @param num_bits Number of bits in the region, must be larger than 0
 * @param offset   Starting bit location
 *
 * @retval 0       Operation successful
 * @retval -EINVAL Invalid argument (e.g. out-of-bounds access, mismatching bitarrays, trying to xor
 * 0 bits, etc.)
 */
int sys_bitarray_xor(sys_bitarray_t *dst, sys_bitarray_t *other, size_t num_bits, size_t offset);
 
int sys_bitarray_find_nth_set(sys_bitarray_t *bitarray, size_t n, size_t num_bits, size_t offset,
                              size_t *found_at);
 
int sys_bitarray_popcount_region(sys_bitarray_t *bitarray, size_t num_bits, size_t offset,
                                 size_t *count);
 
int sys_bitarray_free(sys_bitarray_t *bitarray, size_t num_bits,
                      size_t offset);
 
bool sys_bitarray_is_region_set(sys_bitarray_t *bitarray, size_t num_bits,
                                size_t offset);
 
bool sys_bitarray_is_region_cleared(sys_bitarray_t *bitarray, size_t num_bits,
                                    size_t offset);
 
int sys_bitarray_set_region(sys_bitarray_t *bitarray, size_t num_bits,
                            size_t offset);
 
int sys_bitarray_test_and_set_region(sys_bitarray_t *bitarray, size_t num_bits,
                                     size_t offset, bool to_set);
 
int sys_bitarray_clear_region(sys_bitarray_t *bitarray, size_t num_bits,
                              size_t offset);
 
#ifdef __cplusplus
}
#endif
 
#endif /* ZEPHYR_INCLUDE_SYS_BITARRAY_H_ */