arch/arm/lib/csumpartialcopyuser.S

   1 /*
   2  *  linux/arch/arm/lib/csumpartialcopyuser.S
   3  *
   4  *  Copyright (C) 1995-1998 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  * 27/03/03 Ian Molton Clean up CONFIG_CPU
  11  *
  12  */
  13 #include <linux/linkage.h>
  14 #include <asm/assembler.h>
  15 #include <asm/errno.h>
  16 #include <asm/constants.h>
  17
  18                 .text
  19
  20                 .macro  save_regs
  21                 stmfd   sp!, {r1 - r2, r4 - r8, fp, ip, lr, pc}
  22                 .endm
  23
  24                 .macro  load_regs,flags
  25                 ldm\flags       fp, {r1, r2, r4-r8, fp, sp, pc}
  26                 .endm
  27
  28                 .macro  load1b, reg1
  29 9999:           ldrbt   \reg1, [r0], $1
  30                 .section __ex_table, "a"
  31                 .align  3
  32                 .long   9999b, 6001f
  33                 .previous
  34                 .endm
  35
  36                 .macro  load2b, reg1, reg2
  37 9999:           ldrbt   \reg1, [r0], $1
  38 9998:           ldrbt   \reg2, [r0], $1
  39                 .section __ex_table, "a"
  40                 .long   9999b, 6001f
  41                 .long   9998b, 6001f
  42                 .previous
  43                 .endm
  44
  45                 .macro  load1l, reg1
  46 9999:           ldrt    \reg1, [r0], $4
  47                 .section __ex_table, "a"
  48                 .align  3
  49                 .long   9999b, 6001f
  50                 .previous
  51                 .endm
  52
  53                 .macro  load2l, reg1, reg2
  54 9999:           ldrt    \reg1, [r0], $4
  55 9998:           ldrt    \reg2, [r0], $4
  56                 .section __ex_table, "a"
  57                 .long   9999b, 6001f
  58                 .long   9998b, 6001f
  59                 .previous
  60                 .endm
  61
  62                 .macro  load4l, reg1, reg2, reg3, reg4
  63 9999:           ldrt    \reg1, [r0], $4
  64 9998:           ldrt    \reg2, [r0], $4
  65 9997:           ldrt    \reg3, [r0], $4
  66 9996:           ldrt    \reg4, [r0], $4
  67                 .section __ex_table, "a"
  68                 .long   9999b, 6001f
  69                 .long   9998b, 6001f
  70                 .long   9997b, 6001f
  71                 .long   9996b, 6001f
  72                 .previous
  73                 .endm
  74
  75 /*
  76  * unsigned int
  77  * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
  78  *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
  79  *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
  80  */
  81
  82 #define FN_ENTRY        ENTRY(csum_partial_copy_from_user)
  83
  84 #include "csumpartialcopygeneric.S"
  85
  86 /*
  87  * FIXME: minor buglet here
  88  * We don't return the checksum for the data present in the buffer.  To do
  89  * so properly, we would have to add in whatever registers were loaded before
  90  * the fault, which, with the current asm above is not predictable.
  91  */
  92                 .section .fixup,"ax"
  93                 .align  4
  94 6001:           mov     r4, #-EFAULT
  95                 ldr     r5, [fp, #4]            @ *err_ptr
  96                 str     r4, [r5]
  97                 ldmia   sp, {r1, r2}            @ retrieve dst, len
  98                 add     r2, r2, r1
  99                 mov     r0, #0                  @ zero the buffer
 100 6002:           teq     r2, r1
 101                 strneb  r0, [r1], #1
 102                 bne     6002b
 103                 load_regs       ea
 104                 .previous