arch/sparc64/lib/strncpy_from_user.S

   1 /* $Id: strncpy_from_user.S,v 1.6 1999/05/25 16:53:05 jj Exp $
   2  * strncpy_from_user.S: Sparc64 strncpy from userspace.
   3  *
   4  *  Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
   5  */
   6
   7 #include <asm/asi.h>
   8 #include <asm/errno.h>
   9
  10         .data
  11         .align  8
  12 0:      .xword  0x0101010101010101
  13
  14         .text
  15         .align  32
  16
  17         /* Must return:
  18          *
  19          * -EFAULT              for an exception
  20          * count                if we hit the buffer limit
  21          * bytes copied         if we hit a null byte
  22          * (without the null byte)
  23          *
  24          * This implementation assumes:
  25          * %o1 is 8 aligned => !(%o2 & 7)
  26          * %o0 is 8 aligned (if not, it will be slooooow, but will work)
  27          *
  28          * This is optimized for the common case:
  29          * in my stats, 90% of src are 8 aligned (even on sparc32)
  30          * and average length is 18 or so.
  31          */
  32
  33         .globl  __strncpy_from_user
  34         .type   __strncpy_from_user,#function
  35 __strncpy_from_user:
  36         /* %o0=dest, %o1=src, %o2=count */
  37         andcc   %o1, 7, %g0             ! IEU1  Group
  38         bne,pn  %icc, 30f               ! CTI
  39          add    %o0, %o2, %g3           ! IEU0
  40 60:     ldxa    [%o1] %asi, %g1         ! Load  Group
  41         brlez,pn %o2, 10f               ! CTI
  42          mov    %o0, %o3                ! IEU0
  43 50:     sethi   %hi(0b), %o4            ! IEU0  Group
  44         ldx     [%o4 + %lo(0b)], %o4    ! Load
  45         sllx    %o4, 7, %o5             ! IEU1  Group
  46 1:      sub     %g1, %o4, %g2           ! IEU0  Group
  47         stx     %g1, [%o0]              ! Store
  48         add     %o0, 8, %o0             ! IEU1
  49         andcc   %g2, %o5, %g0           ! IEU1  Group
  50         bne,pn  %xcc, 5f                ! CTI
  51          add    %o1, 8, %o1             ! IEU0
  52         cmp     %o0, %g3                ! IEU1  Group
  53         bl,a,pt %xcc, 1b                ! CTI
  54 61:      ldxa   [%o1] %asi, %g1         ! Load
  55 10:     retl                            ! CTI   Group
  56          mov    %o2, %o0                ! IEU0
  57 5:      srlx    %g2, 32, %g7            ! IEU0  Group
  58         sethi   %hi(0xff00), %o4        ! IEU1
  59         andcc   %g7, %o5, %g0           ! IEU1  Group
  60         be,pn   %icc, 2f                ! CTI
  61          or     %o4, %lo(0xff00), %o4   ! IEU0
  62         srlx    %g1, 48, %g7            ! IEU0  Group
  63         andcc   %g7, %o4, %g0           ! IEU1  Group
  64         be,pn   %icc, 50f               ! CTI
  65          andcc  %g7, 0xff, %g0          ! IEU1  Group
  66         be,pn   %icc, 51f               ! CTI
  67          srlx   %g1, 32, %g7            ! IEU0
  68         andcc   %g7, %o4, %g0           ! IEU1  Group
  69         be,pn   %icc, 52f               ! CTI
  70          andcc  %g7, 0xff, %g0          ! IEU1  Group
  71         be,pn   %icc, 53f               ! CTI
  72 2:       andcc  %g2, %o5, %g0           ! IEU1  Group
  73         be,pn   %icc, 2f                ! CTI
  74          srl    %g1, 16, %g7            ! IEU0
  75         andcc   %g7, %o4, %g0           ! IEU1  Group
  76         be,pn   %icc, 54f               ! CTI
  77          andcc  %g7, 0xff, %g0          ! IEU1  Group
  78         be,pn   %icc, 55f               ! CTI
  79          andcc  %g1, %o4, %g0           ! IEU1  Group
  80         be,pn   %icc, 56f               ! CTI
  81          andcc  %g1, 0xff, %g0          ! IEU1  Group
  82         be,a,pn %icc, 57f               ! CTI
  83          sub    %o0, %o3, %o0           ! IEU0
  84 2:      cmp     %o0, %g3                ! IEU1  Group
  85         bl,a,pt %xcc, 50b               ! CTI
  86 62:      ldxa   [%o1] %asi, %g1         ! Load
  87         retl                            ! CTI   Group
  88          mov    %o2, %o0                ! IEU0
  89 50:     sub     %o0, %o3, %o0
  90         retl
  91          sub    %o0, 8, %o0
  92 51:     sub     %o0, %o3, %o0
  93         retl
  94          sub    %o0, 7, %o0
  95 52:     sub     %o0, %o3, %o0
  96         retl
  97          sub    %o0, 6, %o0
  98 53:     sub     %o0, %o3, %o0
  99         retl
 100          sub    %o0, 5, %o0
 101 54:     sub     %o0, %o3, %o0
 102         retl
 103          sub    %o0, 4, %o0
 104 55:     sub     %o0, %o3, %o0
 105         retl
 106          sub    %o0, 3, %o0
 107 56:     sub     %o0, %o3, %o0
 108         retl
 109          sub    %o0, 2, %o0
 110 57:     retl
 111          sub    %o0, 1, %o0
 112 30:     brlez,pn %o2, 3f
 113          sub    %g0, %o2, %o3
 114         add     %o0, %o2, %o0
 115 63:     lduba   [%o1] %asi, %o4
 116 1:      add     %o1, 1, %o1
 117         brz,pn  %o4, 2f
 118          stb    %o4, [%o0 + %o3]
 119         addcc   %o3, 1, %o3
 120         bne,pt  %xcc, 1b
 121 64:      lduba  [%o1] %asi, %o4
 122 3:      retl
 123          mov    %o2, %o0
 124 2:      retl
 125          add    %o2, %o3, %o0
 126         .size   __strncpy_from_user, .-__strncpy_from_user
 127
 128         .section .fixup,#alloc,#execinstr
 129         .align  4
 130 4:      retl
 131          mov    -EFAULT, %o0
 132
 133         .section __ex_table,#alloc
 134         .align  4
 135         .word   60b, 4b
 136         .word   61b, 4b
 137         .word   62b, 4b
 138         .word   63b, 4b
 139         .word   64b, 4b