| 1 | |
| 2 | |
| 3 | * bitops.c: atomic operations which got too long to be inlined all over
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| 4 | * the place.
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| 5 | *
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| 6 | * Copyright 1999 Philipp Rumpf ([email protected])
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| 7 | * Copyright 2000 Grant Grundler ([email protected])
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| 8 |
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| 9 |
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| 10 | #include <linux/kernel.h>
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| 11 | #include <linux/spinlock.h>
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| 12 | #include <linux/atomic.h>
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| 13 |
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| 14 | #ifdef CONFIG_SMP
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| 15 | arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
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| 16 | [0 ... (ATOMIC_HASH_SIZE-1)] = __ARCH_SPIN_LOCK_UNLOCKED
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| 17 | };
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| 18 | #endif
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| 19 |
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| 20 | #ifdef CONFIG_64BIT
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| 21 | unsigned long notrace __xchg64(unsigned long x, volatile unsigned long *ptr)
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| 22 | {
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| 23 | unsigned long temp, flags;
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| 24 |
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| 25 | _atomic_spin_lock_irqsave(ptr, flags);
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| 26 | temp = *ptr;
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| 27 | *ptr = x;
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| 28 | _atomic_spin_unlock_irqrestore(ptr, flags);
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| 29 | return temp;
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| 30 | }
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| 31 | #endif
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| 32 |
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| 33 | unsigned long notrace __xchg32(int x, volatile int *ptr)
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| 34 | {
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| 35 | unsigned long flags;
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| 36 | long temp;
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| 37 |
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| 38 | _atomic_spin_lock_irqsave(ptr, flags);
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| 39 | temp = (long) *ptr;
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| 40 | *ptr = x;
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| 41 | _atomic_spin_unlock_irqrestore(ptr, flags);
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| 42 | return (unsigned long)temp;
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| 43 | }
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| 44 |
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| 45 |
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| 46 | unsigned long notrace __xchg8(char x, volatile char *ptr)
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| 47 | {
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| 48 | unsigned long flags;
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| 49 | long temp;
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| 50 |
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| 51 | _atomic_spin_lock_irqsave(ptr, flags);
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| 52 | temp = (long) *ptr;
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| 53 | *ptr = x;
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| 54 | _atomic_spin_unlock_irqrestore(ptr, flags);
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| 55 | return (unsigned long)temp;
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| 56 | }
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| 57 |
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| 58 |
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| 59 | #define CMPXCHG(T) \
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| 60 | T notrace __cmpxchg_##T(volatile T *ptr, T old, T new) \
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| 61 | { \
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| 62 | unsigned long flags; \
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| 63 | T prev; \
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| 64 | \
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| 65 | _atomic_spin_lock_irqsave(ptr, flags); \
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| 66 | if ((prev = *ptr) == old) \
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| 67 | *ptr = new; \
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| 68 | _atomic_spin_unlock_irqrestore(ptr, flags); \
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| 69 | return prev; \
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| 70 | }
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| 71 |
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| 72 | CMPXCHG(u64)
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| 73 | CMPXCHG(u32)
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| 74 | CMPXCHG(u16)
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| 75 | CMPXCHG(u8)
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