kernel-ark/arch/sparc/lib/atomic32.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

54 lines
1.0 KiB
C

/*
* atomic32.c: 32-bit atomic_t implementation
*
* Copyright (C) 2004 Keith M Wesolowski
*
* 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 spinlock_t dummy = SPIN_LOCK_UNLOCKED;
#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;
}
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_add_return);
EXPORT_SYMBOL(atomic_set);