diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bitops.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 7d41ae6..387a818 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -1,6 +1,7 @@ #ifndef _LINUX_BITOPS_H #define _LINUX_BITOPS_H +#include <asm/types.h> /* * ffs: find first bit set. This is defined the same way as @@ -66,7 +67,44 @@ static inline unsigned int generic_hweight8(unsigned int w) return (res & 0x0F) + ((res >> 4) & 0x0F); } +#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) +#define BIT_WORD(nr) ((nr) / BITS_PER_LONG) + #include <asm/bitops.h> +/* linux/include/asm-generic/bitops/non-atomic.h */ + +#ifndef __set_bit +# define __set_bit generic_set_bit +#endif + +#ifndef __clear_bit +# define __clear_bit generic_clear_bit +#endif + +/** + * __set_bit - Set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Unlike set_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. + */ +static inline void generic_set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p |= mask; +} + +static inline void generic_clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p &= ~mask; +} #endif |