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 23#define PLATFORM__SET_BIT 24 25static inline void __clear_bit(int nr, volatile unsigned long *addr) 26{ 27 unsigned long mask = BIT_MASK(nr); 28 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 29 30 *p &= ~mask; 31} 32 33#define PLATFORM__CLEAR_BIT 34 35/** 36 * __change_bit - Toggle a bit in memory 37 * @nr: the bit to change 38 * @addr: the address to start counting from 39 * 40 * Unlike change_bit(), this function is non-atomic and may be reordered. 41 * If it's called on the same region of memory simultaneously, the effect 42 * may be that only one operation succeeds. 43 */ 44static inline void __change_bit(int nr, volatile unsigned long *addr) 45{ 46 unsigned long mask = BIT_MASK(nr); 47 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 48 49 *p ^= mask; 50} 51 52/** 53 * __test_and_set_bit - Set a bit and return its old value 54 * @nr: Bit to set 55 * @addr: Address to count from 56 * 57 * This operation is non-atomic and can be reordered. 58 * If two examples of this operation race, one can appear to succeed 59 * but actually fail. You must protect multiple accesses with a lock. 60 */ 61static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) 62{ 63 unsigned long mask = BIT_MASK(nr); 64 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 65 unsigned long old = *p; 66 67 *p = old | mask; 68 return (old & mask) != 0; 69} 70 71/** 72 * __test_and_clear_bit - Clear a bit and return its old value 73 * @nr: Bit to clear 74 * @addr: Address to count from 75 * 76 * This operation is non-atomic and can be reordered. 77 * If two examples of this operation race, one can appear to succeed 78 * but actually fail. You must protect multiple accesses with a lock. 79 */ 80static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) 81{ 82 unsigned long mask = BIT_MASK(nr); 83 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 84 unsigned long old = *p; 85 86 *p = old & ~mask; 87 return (old & mask) != 0; 88} 89 90/* WARNING: non atomic and it can be reordered! */ 91static inline int __test_and_change_bit(int nr, 92 volatile unsigned long *addr) 93{ 94 unsigned long mask = BIT_MASK(nr); 95 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 96 unsigned long old = *p; 97 98 *p = old ^ mask; 99 return (old & mask) != 0; 100} 101 102/** 103 * test_bit - Determine whether a bit is set 104 * @nr: bit number to test 105 * @addr: Address to start counting from 106 */ 107static inline int test_bit(int nr, const volatile unsigned long *addr) 108{ 109 return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); 110} 111 112#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ 113