zephyr/subsys/bluetooth/controller/util/mem.h

68 lines
2.2 KiB
C

/*
* Copyright (c) 2016 Nordic Semiconductor ASA
* Copyright (c) 2016 Vinayak Kariappa Chettimada
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef MALIGN
/**
* @brief Force compiler to place memory at-least on a x-byte boundary
* @details Compiler extension. Supported by GCC and Clang
*/
#define MALIGN(x) __attribute__((aligned(x)))
#endif
#ifndef MROUND
/**
* @brief Round up to nearest multiple of 4, for unsigned integers
* @details
* The addition of 3 forces x into the next multiple of 4. This is responsible
* for the rounding in the the next step, to be Up.
* For ANDing of ~3: We observe y & (~3) == (y>>2)<<2, and we recognize
* (y>>2) as a floored division, which is almost undone by the left-shift. The
* flooring can't be undone so have achieved a rounding.
*
* Examples:
* MROUND( 0) = 0
* MROUND( 1) = 4
* MROUND( 2) = 4
* MROUND( 3) = 4
* MROUND( 4) = 4
* MROUND( 5) = 8
* MROUND( 8) = 8
* MROUND( 9) = 12
* MROUND(13) = 16
*/
#define MROUND(x) (((uint32_t)(x)+3) & (~((uint32_t)3)))
#endif
/* When memory is free in the mem_pool, first few bytes are reserved for
* maintaining the next pointer and free count.
*/
#define MEM_FREE_MEMBER_NEXT_SIZE (sizeof(void *))
#define MEM_FREE_MEMBER_COUNT_SIZE (sizeof(uint16_t))
#define MEM_FREE_RESERVED_SIZE ((MEM_FREE_MEMBER_NEXT_SIZE) + \
(MEM_FREE_MEMBER_COUNT_SIZE))
/* Define to check if a structure member is safe to be accessed when the memory
* is in the mem_pool free list. I.e. whether a structure member be safely
* accessed after the mem being freed.
*/
#define MEM_FREE_MEMBER_ACCESS_BUILD_ASSERT(type, member) \
BUILD_ASSERT(offsetof(type, member) >= MEM_FREE_RESERVED_SIZE, \
"Possible unsafe member access inside free mem pool")
void mem_init(void *mem_pool, uint16_t mem_size, uint16_t mem_count, void **mem_head);
void *mem_acquire(void **mem_head);
void mem_release(void *mem, void **mem_head);
uint16_t mem_free_count_get(void *mem_head);
void *mem_get(void *mem_pool, uint16_t mem_size, uint16_t index);
uint16_t mem_index_get(void *mem, void *mem_pool, uint16_t mem_size);
void mem_rcopy(uint8_t *dst, uint8_t const *src, uint16_t len);
uint8_t mem_nz(uint8_t *src, uint16_t len);
uint32_t mem_ut(void);