rt-thread-official/components/mm/mm_flag.h

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/*
* Copyright (c) 2006-2022, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2022-11-23 WangXiaoyao the first version
*/
#ifndef __MM_FLAG_H__
#define __MM_FLAG_H__
/**
* @brief mm_flag_t
* |max ------- 7|6 ----- 0|
* | control | align |
*
* there should be no more than 25 flags
*/
typedef unsigned long mm_flag_t;
#define _MMF_CNTL_SHIFT 7
#define _MMF_ALIGN_MASK 0x7f
#define _MMF_CNTL_MASK (~((1 << _MMF_CNTL_SHIFT) - 1))
#define _DEF_FLAG(index) (1 << (_MMF_CNTL_SHIFT + (index)))
enum mm_flag_cntl
{
/**
* @brief Indicate a possible COW mapping
*/
MMF_MAP_PRIVATE = _DEF_FLAG(0),
MMF_COW = _DEF_FLAG(1),
/**
* @brief [POSIX MAP_FIXED] When MAP_FIXED is set in the flags argument, the
* implementation is informed that the value of pa shall be addr, exactly.
* If a MAP_FIXED request is successful, the mapping established
* by mmap() replaces any previous mappings for the pages in the range
* [pa,pa+len) of the process.
*/
MMF_MAP_FIXED = _DEF_FLAG(2),
/**
* @brief The backup page frame is allocated and setted only until it is
* truly necessary by the user
*/
MMF_PREFETCH = _DEF_FLAG(3),
/**
* @brief Allocate the mapping using "huge" pages
*/
MMF_HUGEPAGE = _DEF_FLAG(4),
/** internal reserved flags */
MMF_TEXT = _DEF_FLAG(5),
/** internal reserved flags */
MMF_STATIC_ALLOC = _DEF_FLAG(6),
/**
* @brief Shared mapping. Updates to the mapping are visible to other
* processes mapping the same region, and are carried through to the
* underlying file.
*/
MMF_MAP_SHARED = _DEF_FLAG(7),
/**
* @brief a non-locked memory can be swapped out when required, this is
* reserved for future
*/
MMF_NONLOCKED = _DEF_FLAG(8),
/**
* @brief An alignment is specified in flags that the mapping must admit
*/
MMF_REQUEST_ALIGN = _DEF_FLAG(9),
__MMF_INVALID,
};
#define MMF_GET_ALIGN(src) ((src & _MMF_ALIGN_MASK))
#define MMF_SET_ALIGN(src, align) \
((src & ~_MMF_ALIGN_MASK) | (__builtin_ffsl(align) - 1))
#define MMF_GET_CNTL(src) (src & _MMF_CNTL_MASK)
#define MMF_TEST_CNTL(src, flag) (src & flag)
#define MMF_SET_CNTL(src, flag) ((src) | (flag))
#define MMF_CLEAR_CNTL(src, flag) ((src) & ~(flag))
/**
* @brief Create Flags
*
* example: MMF_CREATE(0, 0)
* MMF_CREATE(MMF_MAP_FIXED, 0x2000)
*
* Direct use of flag is also acceptable: (MMF_MAP_FIXED | MMF_PREFETCH)
*/
#define MMF_CREATE(cntl, align) \
((align) ? (MMF_SET_CNTL((mm_flag_t)0, (cntl) | MMF_REQUEST_ALIGN) | \
MMF_SET_ALIGN((mm_flag_t)0, (align))) \
: (MMF_SET_CNTL((mm_flag_t)0, (cntl) & ~MMF_REQUEST_ALIGN)))
#undef _DEF_FLAG
#endif /* __MM_FLAG_H__ */