| /* |
| * bitops.c: atomic operations which got too long to be inlined all over |
| * the place. |
| * |
| * Copyright 1999 Philipp Rumpf (prumpf@tux.org) |
| * Copyright 2000 Grant Grundler (grundler@cup.hp.com) |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/kernel.h> |
| #include <linux/spinlock.h> |
| #include <asm/system.h> |
| #include <asm/atomic.h> |
| |
| #ifdef CONFIG_SMP |
| spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = { |
| [0 ... (ATOMIC_HASH_SIZE-1)] = SPIN_LOCK_UNLOCKED |
| }; |
| #endif |
| |
| #ifdef __LP64__ |
| unsigned long __xchg64(unsigned long x, unsigned long *ptr) |
| { |
| unsigned long temp, flags; |
| |
| _atomic_spin_lock_irqsave(ptr, flags); |
| temp = *ptr; |
| *ptr = x; |
| _atomic_spin_unlock_irqrestore(ptr, flags); |
| return temp; |
| } |
| #endif |
| |
| unsigned long __xchg32(int x, int *ptr) |
| { |
| unsigned long flags; |
| long temp; |
| |
| _atomic_spin_lock_irqsave(ptr, flags); |
| temp = (long) *ptr; /* XXX - sign extension wanted? */ |
| *ptr = x; |
| _atomic_spin_unlock_irqrestore(ptr, flags); |
| return (unsigned long)temp; |
| } |
| |
| |
| unsigned long __xchg8(char x, char *ptr) |
| { |
| unsigned long flags; |
| long temp; |
| |
| _atomic_spin_lock_irqsave(ptr, flags); |
| temp = (long) *ptr; /* XXX - sign extension wanted? */ |
| *ptr = x; |
| _atomic_spin_unlock_irqrestore(ptr, flags); |
| return (unsigned long)temp; |
| } |
| |
| |
| #ifdef __LP64__ |
| unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new) |
| { |
| unsigned long flags; |
| unsigned long prev; |
| |
| _atomic_spin_lock_irqsave(ptr, flags); |
| if ((prev = *ptr) == old) |
| *ptr = new; |
| _atomic_spin_unlock_irqrestore(ptr, flags); |
| return prev; |
| } |
| #endif |
| |
| unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new) |
| { |
| unsigned long flags; |
| unsigned int prev; |
| |
| _atomic_spin_lock_irqsave(ptr, flags); |
| if ((prev = *ptr) == old) |
| *ptr = new; |
| _atomic_spin_unlock_irqrestore(ptr, flags); |
| return (unsigned long)prev; |
| } |