/*
   *  linux/arch/arm/lib/getuser.S
   *
   *  Copyright (C) 2001 Russell King
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   *  Idea from x86 version, (C) Copyright 1998 Linus Torvalds
   *
   * These functions have a non-standard call interface to make them more
   * efficient, especially as they return an error value in addition to
   * the "real" return value.
   *
   * __get_user_X
   *
   * Inputs:	r0 contains the address
   * Outputs:	r0 is the error code
   *		r2, r3 contains the zero-extended value
   *		lr corrupted
   *

   * No other registers must be altered.  (see <asm/uaccess.h>

   * for specific ASM register usage).
   *
   * Note that ADDR_LIMIT is either 0 or 0xc0000000.
   * Note also that it is intended that __get_user_bad is not global.
   */

  #include <linux/linkage.h>

  #include <asm/errno.h>

  #include <asm/domain.h>

  ENTRY(__get_user_1)

  1:	T(ldrb)	r2, [r0]

  	mov	r0, #0
  	mov	pc, lr

  ENDPROC(__get_user_1)

  ENTRY(__get_user_2)

  #ifdef CONFIG_THUMB2_KERNEL

  2:	T(ldrb)	r2, [r0]
  3:	T(ldrb)	r3, [r0, #1]

  #else

  2:	T(ldrb)	r2, [r0], #1
  3:	T(ldrb)	r3, [r0]

  #endif

  #ifndef __ARMEB__
  	orr	r2, r2, r3, lsl #8
  #else
  	orr	r2, r3, r2, lsl #8
  #endif
  	mov	r0, #0
  	mov	pc, lr

  ENDPROC(__get_user_2)

  ENTRY(__get_user_4)

  4:	T(ldr)	r2, [r0]

  	mov	r0, #0
  	mov	pc, lr

  ENDPROC(__get_user_4)

  __get_user_bad:
  	mov	r2, #0
  	mov	r0, #-EFAULT
  	mov	pc, lr

  ENDPROC(__get_user_bad)

  .pushsection __ex_table, "a"

  	.long	1b, __get_user_bad
  	.long	2b, __get_user_bad
  	.long	3b, __get_user_bad
  	.long	4b, __get_user_bad

  .popsection