#ifndef _ASM_GENERIC_FUTEX_H
  #define _ASM_GENERIC_FUTEX_H

  #include <linux/futex.h>

  #include <linux/uaccess.h>

  #include <asm/errno.h>

  #ifndef CONFIG_SMP
  /*
   * The following implementation only for uniprocessor machines.

   * It relies on preempt_disable() ensuring mutual exclusion.

   *
   */
  
  /**
   * futex_atomic_op_inuser() - Atomic arithmetic operation with constant
   *			  argument and comparison of the previous
   *			  futex value with another constant.
   *
   * @encoded_op:	encoded operation to execute
   * @uaddr:	pointer to user space address
   *
   * Return:
   * 0 - On success
   * <0 - On error
   */
  static inline int
  futex_atomic_op_inuser(int encoded_op, u32 __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, ret;
  	u32 tmp;
  
  	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  		oparg = 1 << oparg;

  	preempt_disable();

  	pagefault_disable();
  
  	ret = -EFAULT;
  	if (unlikely(get_user(oldval, uaddr) != 0))
  		goto out_pagefault_enable;
  
  	ret = 0;
  	tmp = oldval;
  
  	switch (op) {
  	case FUTEX_OP_SET:
  		tmp = oparg;
  		break;
  	case FUTEX_OP_ADD:
  		tmp += oparg;
  		break;
  	case FUTEX_OP_OR:
  		tmp |= oparg;
  		break;
  	case FUTEX_OP_ANDN:
  		tmp &= ~oparg;
  		break;
  	case FUTEX_OP_XOR:
  		tmp ^= oparg;
  		break;
  	default:
  		ret = -ENOSYS;
  	}
  
  	if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0))
  		ret = -EFAULT;
  
  out_pagefault_enable:
  	pagefault_enable();

  	preempt_enable();

  
  	if (ret == 0) {
  		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;
  }
  
  /**
   * futex_atomic_cmpxchg_inatomic() - Compare and exchange the content of the
   *				uaddr with newval if the current value is
   *				oldval.
   * @uval:	pointer to store content of @uaddr
   * @uaddr:	pointer to user space address
   * @oldval:	old value
   * @newval:	new value to store to @uaddr
   *
   * Return:
   * 0 - On success
   * <0 - On error
   */
  static inline int
  futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  			      u32 oldval, u32 newval)
  {
  	u32 val;

  	preempt_disable();

  	if (unlikely(get_user(val, uaddr) != 0)) {
  		preempt_enable();

  		return -EFAULT;

  	}

  	if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) {
  		preempt_enable();

  		return -EFAULT;

  	}

  
  	*uval = val;

  	preempt_enable();

  
  	return 0;
  }
  
  #else

  static inline int

  futex_atomic_op_inuser (int encoded_op, u32 __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(u32)))

  		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(u32 *uval, u32 __user *uaddr,
  			      u32 oldval, u32 newval)

  {
  	return -ENOSYS;
  }

  #endif /* CONFIG_SMP */

  #endif