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