#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ #define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ #include <asm/types.h> #define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) #define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) /** * __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 __set_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); *p |= mask; } static inline void __clear_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); *p &= ~mask; } /** * __change_bit - Toggle a bit in memory * @nr: the bit to change * @addr: the address to start counting from * * Unlike change_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 __change_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); *p ^= mask; } /** * __test_and_set_bit - Set a bit and return its old value * @nr: Bit to set * @addr: Address to count from * * This operation is non-atomic and can be reordered. * If two examples of this operation race, one can appear to succeed * but actually fail. You must protect multiple accesses with a lock. */ static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); unsigned long old = *p; *p = old | mask; return (old & mask) != 0; } /** * __test_and_clear_bit - Clear a bit and return its old value * @nr: Bit to clear * @addr: Address to count from * * This operation is non-atomic and can be reordered. * If two examples of this operation race, one can appear to succeed * but actually fail. You must protect multiple accesses with a lock. */ static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); unsigned long old = *p; *p = old & ~mask; return (old & mask) != 0; } /* WARNING: non atomic and it can be reordered! */ static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); unsigned long old = *p; *p = old ^ mask; return (old & mask) != 0; } /** * test_bit - Determine whether a bit is set * @nr: bit number to test * @addr: Address to start counting from */ static inline int test_bit(int nr, const volatile unsigned long *addr) { return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); } #endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */