1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ 3 #define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ 4 5 #include <asm/types.h> 6 7 /** 8 * arch___set_bit - Set a bit in memory 9 * @nr: the bit to set 10 * @addr: the address to start counting from 11 * 12 * Unlike set_bit(), this function is non-atomic and may be reordered. 13 * If it's called on the same region of memory simultaneously, the effect 14 * may be that only one operation succeeds. 15 */ 16 static __always_inline void 17 arch___set_bit(unsigned int nr, volatile unsigned long *addr) 18 { 19 unsigned long mask = BIT_MASK(nr); 20 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 21 22 *p |= mask; 23 } 24 #define __set_bit arch___set_bit 25 26 static __always_inline void 27 arch___clear_bit(unsigned int nr, volatile unsigned long *addr) 28 { 29 unsigned long mask = BIT_MASK(nr); 30 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 31 32 *p &= ~mask; 33 } 34 #define __clear_bit arch___clear_bit 35 36 /** 37 * arch___change_bit - Toggle a bit in memory 38 * @nr: the bit to change 39 * @addr: the address to start counting from 40 * 41 * Unlike change_bit(), this function is non-atomic and may be reordered. 42 * If it's called on the same region of memory simultaneously, the effect 43 * may be that only one operation succeeds. 44 */ 45 static __always_inline 46 void arch___change_bit(unsigned int nr, volatile unsigned long *addr) 47 { 48 unsigned long mask = BIT_MASK(nr); 49 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 50 51 *p ^= mask; 52 } 53 #define __change_bit arch___change_bit 54 55 /** 56 * arch___test_and_set_bit - Set a bit and return its old value 57 * @nr: Bit to set 58 * @addr: Address to count from 59 * 60 * This operation is non-atomic and can be reordered. 61 * If two examples of this operation race, one can appear to succeed 62 * but actually fail. You must protect multiple accesses with a lock. 63 */ 64 static __always_inline int 65 arch___test_and_set_bit(unsigned int nr, volatile unsigned long *addr) 66 { 67 unsigned long mask = BIT_MASK(nr); 68 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 69 unsigned long old = *p; 70 71 *p = old | mask; 72 return (old & mask) != 0; 73 } 74 #define __test_and_set_bit arch___test_and_set_bit 75 76 /** 77 * arch___test_and_clear_bit - Clear a bit and return its old value 78 * @nr: Bit to clear 79 * @addr: Address to count from 80 * 81 * This operation is non-atomic and can be reordered. 82 * If two examples of this operation race, one can appear to succeed 83 * but actually fail. You must protect multiple accesses with a lock. 84 */ 85 static __always_inline int 86 arch___test_and_clear_bit(unsigned int nr, volatile unsigned long *addr) 87 { 88 unsigned long mask = BIT_MASK(nr); 89 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 90 unsigned long old = *p; 91 92 *p = old & ~mask; 93 return (old & mask) != 0; 94 } 95 #define __test_and_clear_bit arch___test_and_clear_bit 96 97 /* WARNING: non atomic and it can be reordered! */ 98 static __always_inline int 99 arch___test_and_change_bit(unsigned int nr, volatile unsigned long *addr) 100 { 101 unsigned long mask = BIT_MASK(nr); 102 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 103 unsigned long old = *p; 104 105 *p = old ^ mask; 106 return (old & mask) != 0; 107 } 108 #define __test_and_change_bit arch___test_and_change_bit 109 110 /** 111 * arch_test_bit - Determine whether a bit is set 112 * @nr: bit number to test 113 * @addr: Address to start counting from 114 */ 115 static __always_inline int 116 arch_test_bit(unsigned int nr, const volatile unsigned long *addr) 117 { 118 return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); 119 } 120 #define test_bit arch_test_bit 121 122 #endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ 123