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Diffstat (limited to 'src/helper/bits.h')
-rw-r--r-- | src/helper/bits.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/src/helper/bits.h b/src/helper/bits.h new file mode 100644 index 0000000..464584d --- /dev/null +++ b/src/helper/bits.h @@ -0,0 +1,84 @@ +/* + * Copyright (C) 2018, STMicroelectronics - All Rights Reserved + * Author(s): Antonio Borneo <borneo.antonio@gmail.com> for STMicroelectronics + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* + * 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/types.h> + +#define BIT(nr) (1UL << (nr)) +#define BITS_PER_BYTE 8 +#define BITS_PER_LONG (BITS_PER_BYTE * sizeof(long)) +#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 + * @dst: the address of the bitmap + * @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 + * @nr: the bit to set + * @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 + * @nr: the bit to set + * @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 + * @nr: bit number to test + * @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 */ |