arch/arm/lib/putuser.S

   1 /*
   2  *  linux/arch/arm/lib/putuser.S
   3  *
   4  *  Copyright (C) 2001 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Idea from x86 version, (C) Copyright 1998 Linus Torvalds
  11  *
  12  * These functions have a non-standard call interface to make
  13  * them more efficient, especially as they return an error
  14  * value in addition to the "real" return value.
  15  *
  16  * __put_user_X
  17  *
  18  * Inputs:      r0 contains the address
  19  *              r2, r3 contains the value
  20  * Outputs:     r0 is the error code
  21  *              lr corrupted
  22  *
  23  * No other registers must be altered.  (see <asm/uaccess.h>
  24  * for specific ASM register usage).
  25  *
  26  * Note that ADDR_LIMIT is either 0 or 0xc0000000
  27  * Note also that it is intended that __put_user_bad is not global.
  28  */
  29 #include <linux/linkage.h>
  30 #include <asm/errno.h>
  31 #include <asm/domain.h>
  32
  33 ENTRY(__put_user_1)
  34 1: TUSER(strb)  r2, [r0]
  35         mov     r0, #0
  36         mov     pc, lr
  37 ENDPROC(__put_user_1)
  38
  39 ENTRY(__put_user_2)
  40         mov     ip, r2, lsr #8
  41 #ifdef CONFIG_THUMB2_KERNEL
  42 #ifndef __ARMEB__
  43 2: TUSER(strb)  r2, [r0]
  44 3: TUSER(strb)  ip, [r0, #1]
  45 #else
  46 2: TUSER(strb)  ip, [r0]
  47 3: TUSER(strb)  r2, [r0, #1]
  48 #endif
  49 #else   /* !CONFIG_THUMB2_KERNEL */
  50 #ifndef __ARMEB__
  51 2: TUSER(strb)  r2, [r0], #1
  52 3: TUSER(strb)  ip, [r0]
  53 #else
  54 2: TUSER(strb)  ip, [r0], #1
  55 3: TUSER(strb)  r2, [r0]
  56 #endif
  57 #endif  /* CONFIG_THUMB2_KERNEL */
  58         mov     r0, #0
  59         mov     pc, lr
  60 ENDPROC(__put_user_2)
  61
  62 ENTRY(__put_user_4)
  63 4: TUSER(str)   r2, [r0]
  64         mov     r0, #0
  65         mov     pc, lr
  66 ENDPROC(__put_user_4)
  67
  68 ENTRY(__put_user_8)
  69 #ifdef CONFIG_THUMB2_KERNEL
  70 5: TUSER(str)   r2, [r0]
  71 6: TUSER(str)   r3, [r0, #4]
  72 #else
  73 5: TUSER(str)   r2, [r0], #4
  74 6: TUSER(str)   r3, [r0]
  75 #endif
  76         mov     r0, #0
  77         mov     pc, lr
  78 ENDPROC(__put_user_8)
  79
  80 __put_user_bad:
  81         mov     r0, #-EFAULT
  82         mov     pc, lr
  83 ENDPROC(__put_user_bad)
  84
  85 .pushsection __ex_table, "a"
  86         .long   1b, __put_user_bad
  87         .long   2b, __put_user_bad
  88         .long   3b, __put_user_bad
  89         .long   4b, __put_user_bad
  90         .long   5b, __put_user_bad
  91         .long   6b, __put_user_bad
  92 .popsection