1#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ 2#define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ 3 4#include <asm/types.h> 5 6/** 7 * __set_bit - Set a bit in memory 8 * @nr: the bit to set 9 * @addr: the address to start counting from 10 * 11 * Unlike set_bit(), this function is non-atomic and may be reordered. 12 * If it's called on the same region of memory simultaneously, the effect 13 * may be that only one operation succeeds. 14 */ 15static inline void __set_bit(int nr, volatile unsigned long *addr) 16{ 17 unsigned long mask = BIT_MASK(nr); 18 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 19 20 *p |= mask; 21} 22 23static inline void __clear_bit(int nr, volatile unsigned long *addr) 24{ 25 unsigned long mask = BIT_MASK(nr); 26 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 27 28 *p &= ~mask; 29} 30 31/** 32 * __change_bit - Toggle a bit in memory 33 * @nr: the bit to change 34 * @addr: the address to start counting from 35 * 36 * Unlike change_bit(), this function is non-atomic and may be reordered. 37 * If it's called on the same region of memory simultaneously, the effect 38 * may be that only one operation succeeds. 39 */ 40static inline void __change_bit(int nr, volatile unsigned long *addr) 41{ 42 unsigned long mask = BIT_MASK(nr); 43 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 44 45 *p ^= mask; 46} 47 48/** 49 * __test_and_set_bit - Set a bit and return its old value 50 * @nr: Bit to set 51 * @addr: Address to count from 52 * 53 * This operation is non-atomic and can be reordered. 54 * If two examples of this operation race, one can appear to succeed 55 * but actually fail. You must protect multiple accesses with a lock. 56 */ 57static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) 58{ 59 unsigned long mask = BIT_MASK(nr); 60 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 61 unsigned long old = *p; 62 63 *p = old | mask; 64 return (old & mask) != 0; 65} 66 67/** 68 * __test_and_clear_bit - Clear a bit and return its old value 69 * @nr: Bit to clear 70 * @addr: Address to count from 71 * 72 * This operation is non-atomic and can be reordered. 73 * If two examples of this operation race, one can appear to succeed 74 * but actually fail. You must protect multiple accesses with a lock. 75 */ 76static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) 77{ 78 unsigned long mask = BIT_MASK(nr); 79 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 80 unsigned long old = *p; 81 82 *p = old & ~mask; 83 return (old & mask) != 0; 84} 85 86/* WARNING: non atomic and it can be reordered! */ 87static inline int __test_and_change_bit(int nr, 88 volatile unsigned long *addr) 89{ 90 unsigned long mask = BIT_MASK(nr); 91 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 92 unsigned long old = *p; 93 94 *p = old ^ mask; 95 return (old & mask) != 0; 96} 97 98/** 99 * test_bit - Determine whether a bit is set 100 * @nr: bit number to test 101 * @addr: Address to start counting from 102 */ 103static inline int test_bit(int nr, const volatile unsigned long *addr) 104{ 105 return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); 106} 107 108#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ 109