1/* 2 * bitops.c: atomic operations which got too long to be inlined all over 3 * the place. 4 * 5 * Copyright 1999 Philipp Rumpf (prumpf@tux.org) 6 * Copyright 2000 Grant Grundler (grundler@cup.hp.com) 7 */ 8 9#include <linux/kernel.h> 10#include <linux/spinlock.h> 11#include <asm/system.h> 12#include <asm/atomic.h> 13 14#ifdef CONFIG_SMP 15raw_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = { 16 [0 ... (ATOMIC_HASH_SIZE-1)] = __RAW_SPIN_LOCK_UNLOCKED 17}; 18#endif 19 20#ifdef CONFIG_64BIT 21unsigned long __xchg64(unsigned long x, unsigned long *ptr) 22{ 23 unsigned long temp, flags; 24 25 _atomic_spin_lock_irqsave(ptr, flags); 26 temp = *ptr; 27 *ptr = x; 28 _atomic_spin_unlock_irqrestore(ptr, flags); 29 return temp; 30} 31#endif 32 33unsigned long __xchg32(int x, int *ptr) 34{ 35 unsigned long flags; 36 long temp; 37 38 _atomic_spin_lock_irqsave(ptr, flags); 39 temp = (long) *ptr; 40 *ptr = x; 41 _atomic_spin_unlock_irqrestore(ptr, flags); 42 return (unsigned long)temp; 43} 44 45 46unsigned long __xchg8(char x, char *ptr) 47{ 48 unsigned long flags; 49 long temp; 50 51 _atomic_spin_lock_irqsave(ptr, flags); 52 temp = (long) *ptr; 53 *ptr = x; 54 _atomic_spin_unlock_irqrestore(ptr, flags); 55 return (unsigned long)temp; 56} 57 58 59#ifdef CONFIG_64BIT 60unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new) 61{ 62 unsigned long flags; 63 unsigned long prev; 64 65 _atomic_spin_lock_irqsave(ptr, flags); 66 if ((prev = *ptr) == old) 67 *ptr = new; 68 _atomic_spin_unlock_irqrestore(ptr, flags); 69 return prev; 70} 71#endif 72 73unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new) 74{ 75 unsigned long flags; 76 unsigned int prev; 77 78 _atomic_spin_lock_irqsave(ptr, flags); 79 if ((prev = *ptr) == old) 80 *ptr = new; 81 _atomic_spin_unlock_irqrestore(ptr, flags); 82 return (unsigned long)prev; 83} 84