| /* |
| * atomic32.c: 32-bit atomic_t implementation |
| * |
| * Copyright (C) 2004 Keith M Wesolowski |
| * Copyright (C) 2007 Kyle McMartin |
| * |
| * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf |
| */ |
| |
| #include <asm/atomic.h> |
| #include <linux/spinlock.h> |
| #include <linux/module.h> |
| |
| #ifdef CONFIG_SMP |
| #define ATOMIC_HASH_SIZE 4 |
| #define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)]) |
| |
| spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = { |
| [0 ... (ATOMIC_HASH_SIZE-1)] = SPIN_LOCK_UNLOCKED |
| }; |
| |
| #else /* SMP */ |
| |
| static DEFINE_SPINLOCK(dummy); |
| #define ATOMIC_HASH_SIZE 1 |
| #define ATOMIC_HASH(a) (&dummy) |
| |
| #endif /* SMP */ |
| |
| int __atomic_add_return(int i, atomic_t *v) |
| { |
| int ret; |
| unsigned long flags; |
| spin_lock_irqsave(ATOMIC_HASH(v), flags); |
| |
| ret = (v->counter += i); |
| |
| spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
| return ret; |
| } |
| EXPORT_SYMBOL(__atomic_add_return); |
| |
| int atomic_cmpxchg(atomic_t *v, int old, int new) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(ATOMIC_HASH(v), flags); |
| ret = v->counter; |
| if (likely(ret == old)) |
| v->counter = new; |
| |
| spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
| return ret; |
| } |
| EXPORT_SYMBOL(atomic_cmpxchg); |
| |
| int atomic_add_unless(atomic_t *v, int a, int u) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(ATOMIC_HASH(v), flags); |
| ret = v->counter; |
| if (ret != u) |
| v->counter += a; |
| spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
| return ret != u; |
| } |
| EXPORT_SYMBOL(atomic_add_unless); |
| |
| /* Atomic operations are already serializing */ |
| void atomic_set(atomic_t *v, int i) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(ATOMIC_HASH(v), flags); |
| v->counter = i; |
| spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
| } |
| EXPORT_SYMBOL(atomic_set); |
| |
| unsigned long ___set_bit(unsigned long *addr, unsigned long mask) |
| { |
| unsigned long old, flags; |
| |
| spin_lock_irqsave(ATOMIC_HASH(addr), flags); |
| old = *addr; |
| *addr = old | mask; |
| spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); |
| |
| return old & mask; |
| } |
| EXPORT_SYMBOL(___set_bit); |
| |
| unsigned long ___clear_bit(unsigned long *addr, unsigned long mask) |
| { |
| unsigned long old, flags; |
| |
| spin_lock_irqsave(ATOMIC_HASH(addr), flags); |
| old = *addr; |
| *addr = old & ~mask; |
| spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); |
| |
| return old & mask; |
| } |
| EXPORT_SYMBOL(___clear_bit); |
| |
| unsigned long ___change_bit(unsigned long *addr, unsigned long mask) |
| { |
| unsigned long old, flags; |
| |
| spin_lock_irqsave(ATOMIC_HASH(addr), flags); |
| old = *addr; |
| *addr = old ^ mask; |
| spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); |
| |
| return old & mask; |
| } |
| EXPORT_SYMBOL(___change_bit); |
| |
| unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new) |
| { |
| unsigned long flags; |
| u32 prev; |
| |
| spin_lock_irqsave(ATOMIC_HASH(addr), flags); |
| if ((prev = *ptr) == old) |
| *ptr = new; |
| spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); |
| |
| return (unsigned long)prev; |
| } |
| EXPORT_SYMBOL(__cmpxchg_u32); |