81 строка
1.7 KiB
C
81 строка
1.7 KiB
C
/*
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* bitops.c: atomic operations which got too long to be inlined all over
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* the place.
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*
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* Copyright 1999 Philipp Rumpf (prumpf@tux.org)
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* Copyright 2000 Grant Grundler (grundler@cup.hp.com)
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*/
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#include <linux/kernel.h>
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#include <linux/spinlock.h>
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#include <linux/atomic.h>
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#ifdef CONFIG_SMP
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arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
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[0 ... (ATOMIC_HASH_SIZE-1)] = __ARCH_SPIN_LOCK_UNLOCKED
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};
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#endif
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#ifdef CONFIG_64BIT
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unsigned long __xchg64(unsigned long x, unsigned long *ptr)
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{
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unsigned long temp, flags;
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_atomic_spin_lock_irqsave(ptr, flags);
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temp = *ptr;
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*ptr = x;
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_atomic_spin_unlock_irqrestore(ptr, flags);
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return temp;
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}
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#endif
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unsigned long __xchg32(int x, int *ptr)
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{
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unsigned long flags;
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long temp;
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_atomic_spin_lock_irqsave(ptr, flags);
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temp = (long) *ptr; /* XXX - sign extension wanted? */
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*ptr = x;
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_atomic_spin_unlock_irqrestore(ptr, flags);
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return (unsigned long)temp;
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}
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unsigned long __xchg8(char x, char *ptr)
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{
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unsigned long flags;
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long temp;
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_atomic_spin_lock_irqsave(ptr, flags);
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temp = (long) *ptr; /* XXX - sign extension wanted? */
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*ptr = x;
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_atomic_spin_unlock_irqrestore(ptr, flags);
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return (unsigned long)temp;
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}
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u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new)
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{
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unsigned long flags;
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u64 prev;
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_atomic_spin_lock_irqsave(ptr, flags);
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if ((prev = *ptr) == old)
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*ptr = new;
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_atomic_spin_unlock_irqrestore(ptr, flags);
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return prev;
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}
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unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
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{
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unsigned long flags;
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unsigned int prev;
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_atomic_spin_lock_irqsave(ptr, flags);
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if ((prev = *ptr) == old)
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*ptr = new;
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_atomic_spin_unlock_irqrestore(ptr, flags);
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return (unsigned long)prev;
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}
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