incubator-nuttx/include/nuttx/bits.h

176 lines
5.9 KiB
C

/****************************************************************************
* include/nuttx/bits.h
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_BITS_H
#define __INCLUDE_NUTTX_BITS_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <assert.h>
#include <limits.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef BITS_PER_BYTE
# define BITS_PER_BYTE CHAR_BIT
#endif
#ifndef BITS_PER_LONG
# define BITS_PER_LONG (sizeof(unsigned long) * BITS_PER_BYTE)
#endif
#ifndef BITS_TO_LONGS
# define BITS_TO_LONGS(nr) (((nr) + BITS_PER_LONG - 1) / BITS_PER_LONG)
#endif
#ifndef BITS_PER_LONG_LONG
# define BITS_PER_LONG_LONG (sizeof(unsigned long long) * BITS_PER_BYTE)
#endif
#define BIT_BYTE_MASK(nr) (1ul << ((nr) % BITS_PER_BYTE))
#define BIT_WORD_MASK(nr) (1ul << ((nr) % BITS_PER_LONG))
#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
#define BIT_ULL_MASK(nr) (1ull << ((nr) % BITS_PER_LONG_LONG))
#define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
#define BIT(nr) (1ul << (nr))
#define BIT_ULL(nr) (1ull << (nr))
/* Create a contiguous bitmask starting at bit position l and ending at
* position h. For example
* GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
*/
#define __GENMASK(h, l) \
(((~0ul) - (1ul << (l)) + 1) & \
(~0ul >> (BITS_PER_LONG - 1 - (h))))
#define GENMASK(h, l) \
(BUILD_BUG_ON_ZERO((l) > (h)) + __GENMASK(h, l))
#define __GENMASK_ULL(h, l) \
(((~0ull) - (1ull << (l)) + 1) & \
(~0ull >> (BITS_PER_LONG_LONG - 1 - (h))))
#define GENMASK_ULL(h, l) \
(BUILD_BUG_ON_ZERO((l) > (h)) + __GENMASK_ULL(h, l))
#define BMVAL(val, lsb, msb) (((val) & GENMASK(msb, lsb)) >> (lsb))
/* Bitmap operations */
#define DECLARE_BITMAP(name, bits) \
unsigned long name[BITS_TO_LONGS(bits)]
#define BITMAP_FIRST_WORD_MASK(start) (~0ul << ((start) & (BITS_PER_LONG - 1)))
#define BITMAP_LAST_WORD_MASK(len) (~0ul >> (-(len) & (BITS_PER_LONG - 1)))
#define set_bit(nr, addr) \
(*(((FAR unsigned long *)(addr)) + BIT_WORD(nr)) |= \
BIT_WORD_MASK(nr))
#define clear_bit(nr, addr) \
(*(((FAR unsigned long *)(addr)) + BIT_WORD(nr)) &= \
~BIT_WORD_MASK(nr))
#define test_bit(nr, addr) \
(*(((FAR unsigned long *)(addr)) + BIT_WORD(nr)) & \
BIT_WORD_MASK(nr))
#define find_first_bit(addr, size) find_next_bit(addr, size, 0)
#define find_first_zero_bit(addr, size) find_next_zero_bit(addr, size, 0)
/****************************************************************************
* Type Definitions
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifndef __ASSEMBLER__
unsigned long find_next_bit(FAR const unsigned long *addr,
unsigned long size,
unsigned long offset);
unsigned long find_next_zero_bit(FAR const unsigned long *addr,
unsigned long size,
unsigned long offset);
void bitmap_set(FAR unsigned long *bitmap,
unsigned long satrt,
unsigned long len);
void bitmap_clear(FAR unsigned long *bitmap,
unsigned long start,
unsigned long len);
int bitmap_allocate_region(FAR unsigned long *bitmap,
unsigned long start,
unsigned long len);
#define bitmap_release_region(bitmap, start, len) \
bitmap_clear(bitmap, start, len)
/****************************************************************************
* Name: bitmap_find_free_region
*
* Description:
* Find a contiguous memory region
*
* Find a region of free (zero) len in a bitmap of size and
* allocate them (set them to one).
*
* Input Parameters:
* bitmap - Array of unsigned longs corresponding to the bitmap
* size - Number of bits in the bitmap
* len - Region size to find
*
* Returned Value:
* Return the bit offset in bitmap of the allocated region,
* otherwise return size
****************************************************************************/
unsigned long bitmap_find_free_region(FAR unsigned long *bitmap,
unsigned long size,
unsigned long len);
#endif
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_BITS_H */