#ifndef _ASM_GENERIC_FUTEX_H
#define _ASM_GENERIC_FUTEX_H

#ifdef __KERNEL__

#include <linux/futex.h>
#include <linux/preempt.h>
#include <asm/errno.h>
#include <asm/uaccess.h>

static inline int
futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
{
	int op = (encoded_op >> 28) & 7;
	int cmp = (encoded_op >> 24) & 15;
	int oparg = (encoded_op << 8) >> 20;
	int cmparg = (encoded_op << 20) >> 20;
	int oldval = 0, ret;
	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
		oparg = 1 << oparg;

	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
		return -EFAULT;

	pagefault_disable();

	switch (op) {
	case FUTEX_OP_SET:
	case FUTEX_OP_ADD:
	case FUTEX_OP_OR:
	case FUTEX_OP_ANDN:
	case FUTEX_OP_XOR:
	default:
		ret = -ENOSYS;
	}

	pagefault_enable();

	if (!ret) {
		switch (cmp) {
		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
		default: ret = -ENOSYS;
		}
	}
	return ret;
}

static inline int
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
{
#ifdef CONFIG_SMP
	return -ENOSYS;
#else
	int curval, ret;

	if(!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
		return -EFAULT;

	preempt_disable();

	ret = -EFAULT;

	if(__copy_from_user_inatomic(&curval, uaddr, sizeof(int)))
		goto out;
	
	ret = curval;
	if(curval != oldval)
		goto out;

	ret = -EFAULT;

	if(__copy_to_user_inatomic(uaddr, &newval, sizeof(int)))
		goto out;

	ret = newval;

out :
	preempt_enable();
	return ret;
#endif
}

#endif
#endif
