/**
 * \file futex.h
 * Licence details are found in the file LICENSE.
 *  
 * \brief
 * Futex adaptation to McKernel
 *
 * \author Balazs Gerofi  <bgerofi@riken.jp> \par
 * Copyright (C) 2012  RIKEN AICS
 *
 *
 * HISTORY:
 *
 */
#ifndef _ARCH_FUTEX_H
#define _ARCH_FUTEX_H
#include <asm.h>

#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg)	\
	asm volatile("1:\t" insn "\n"				\
		     "2:\t.section .fixup,\"ax\"\n"		\
		     "3:\tmov\t%3, %1\n"			\
		     "\tjmp\t2b\n"				\
		     "\t.previous\n"				\
		     _ASM_EXTABLE(1b, 3b)			\
		     : "=r" (oldval), "=r" (ret), "+m" (*uaddr)	\
		     : "i" (-EFAULT), "0" (oparg), "1" (0))

#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg)	\
	asm volatile("1:\tmovl	%2, %0\n"			\
		     "\tmovl\t%0, %3\n"				\
		     "\t" insn "\n"				\
		     "2:\tlock; cmpxchgl %3, %2\n"		\
		     "\tjnz\t1b\n"				\
		     "3:\t.section .fixup,\"ax\"\n"		\
		     "4:\tmov\t%5, %1\n"			\
		     "\tjmp\t3b\n"				\
		     "\t.previous\n"				\
		     _ASM_EXTABLE(1b, 4b)			\
		     _ASM_EXTABLE(2b, 4b)			\
		     : "=&a" (oldval), "=&r" (ret),		\
		       "+m" (*uaddr), "=&r" (tem)		\
		     : "r" (oparg), "i" (-EFAULT), "1" (0))

static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval,
						int newval)
{
#ifdef __UACCESS__
	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
		return -EFAULT;
#endif

	asm volatile("1:\tlock; cmpxchgl %3, %1\n"
		     "2:\t.section .fixup, \"ax\"\n"
		     "3:\tmov     %2, %0\n"
		     "\tjmp     2b\n"
		     "\t.previous\n"
		     _ASM_EXTABLE(1b, 3b)
		     : "=a" (oldval), "+m" (*uaddr)
		     : "i" (-EFAULT), "r" (newval), "0" (oldval)
		     : "memory"
	);

	return oldval;
}

#endif