openocd/src/helper/bits.h

79 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2018, STMicroelectronics - All Rights Reserved
* Author(s): Antonio Borneo <borneo.antonio@gmail.com> for STMicroelectronics
*/
/*
* The content of this file is mainly copied/inspired from Linux kernel
* code in include/linux/types.h include/linux/bitmap.h include/linux/bitops.h
*/
#ifndef OPENOCD_HELPER_BITS_H
#define OPENOCD_HELPER_BITS_H
#include <helper/replacements.h>
#include <helper/types.h>
#define BIT(nr) (1UL << (nr))
#define BIT_ULL(nr) (1ULL << (nr))
#define BITS_PER_BYTE 8
#define BITS_PER_LONG (BITS_PER_BYTE * sizeof(long))
#define BITS_PER_LONG_LONG (BITS_PER_BYTE * sizeof(long long))
#define GENMASK(h, l) (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
#define GENMASK_ULL(h, l) (((~0ULL) - (1ULL << (l)) + 1) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
#define DECLARE_BITMAP(name, bits) unsigned long name[BITS_TO_LONGS(bits)]
/**
* bitmap_zero - Clears all the bits in memory
* @param dst the address of the bitmap
* @param nbits the number of bits to clear
*/
static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
memset(dst, 0, len);
}
/**
* clear_bit - Clear a bit in memory
* @param nr the bit to set
* @param addr the address to start counting from
*/
static inline void clear_bit(unsigned int nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
*p &= ~mask;
}
/**
* set_bit - Set a bit in memory
* @param nr the bit to set
* @param addr the address to start counting from
*/
static inline void set_bit(unsigned int nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
*p |= mask;
}
/**
* test_bit - Determine whether a bit is set
* @param nr bit number to test
* @param addr Address to start counting from
*/
static inline int test_bit(unsigned int nr, const volatile unsigned long *addr)
{
return 1UL & (addr[BIT_WORD(nr)] >> (nr % BITS_PER_LONG));
}
#endif /* OPENOCD_HELPER_BITS_H */