arch/avr32/lib/csum_partial_copy_generic.S

   1 /*
   2  * Copyright (C) 2004-2006 Atmel Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #include <asm/errno.h>
   9 #include <asm/asm.h>
  10
  11         /*
  12          * unsigned int csum_partial_copy_generic(const char *src, char *dst, int len
  13          *                                        int sum, int *src_err_ptr,
  14          *                                        int *dst_err_ptr)
  15          *
  16          * Copy src to dst while checksumming, otherwise like csum_partial.
  17          */
  18
  19         .macro ld_src size, reg, ptr
  20 9999:   ld.\size \reg, \ptr
  21         .section __ex_table, "a"
  22         .long   9999b, fixup_ld_src
  23         .previous
  24         .endm
  25
  26         .macro st_dst size, ptr, reg
  27 9999:   st.\size \ptr, \reg
  28         .section __ex_table, "a"
  29         .long   9999b, fixup_st_dst
  30         .previous
  31         .endm
  32
  33         .text
  34         .global csum_partial_copy_generic
  35         .type   csum_partial_copy_generic,"function"
  36         .align  1
  37 csum_partial_copy_generic:
  38         pushm   r4-r7,lr
  39
  40         /* The inner loop */
  41 1:      sub     r10, 4
  42         brlt    5f
  43 2:      ld_src  w, r5, r12++
  44         st_dst  w, r11++, r5
  45         add     r9, r5
  46         acr     r9
  47         sub     r10, 4
  48         brge    2b
  49
  50         /* return if we had a whole number of words */
  51 5:      sub     r10, -4
  52         brne    7f
  53
  54 6:      mov     r12, r9
  55         popm    r4-r7,pc
  56
  57         /* handle additional bytes at the tail */
  58 7:      mov     r5, 0
  59         mov     r4, 32
  60 8:      ld_src  ub, r6, r12++
  61         st_dst  b, r11++, r6
  62         lsl     r5, 8
  63         sub     r4, 8
  64         bfins   r5, r6, 0, 8
  65         sub     r10, 1
  66         brne    8b
  67
  68         lsl     r5, r5, r4
  69         add     r9, r5
  70         acr     r9
  71         rjmp    6b
  72
  73         /* Exception handler */
  74         .section .fixup,"ax"
  75         .align  1
  76 fixup_ld_src:
  77         mov     r9, -EFAULT
  78         cp.w    r8, 0
  79         breq    1f
  80         st.w    r8[0], r9
  81
  82 1:      /*
  83          * TODO: zero the complete destination - computing the rest
  84          * is too much work
  85          */
  86
  87         mov     r9, 0
  88         rjmp    6b
  89
  90 fixup_st_dst:
  91         mov     r9, -EFAULT
  92         lddsp   r8, sp[20]
  93         cp.w    r8, 0
  94         breq    1f
  95         st.w    r8[0], r9
  96 1:      mov     r9, 0
  97         rjmp    6b
  98
  99         .previous