arch/arm26/lib/csumpartialcopyuser.S

   1 /*
   2  *  linux/arch/arm26/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 #include <linux/config.h>
  11 #include <linux/linkage.h>
  12 #include <asm/assembler.h>
  13 #include <asm/errno.h>
  14 #include <asm/asm_offsets.h>
  15
  16                 .text
  17
  18                 .macro  save_regs
  19                 stmfd   sp!, {r1 - r2, r4 - r9, fp, ip, lr, pc}
  20                 mov     r9, sp, lsr #13
  21                 mov     r9, r9, lsl #13
  22                 ldr     r9, [r9, #TSK_ADDR_LIMIT]
  23                 mov     r9, r9, lsr #24
  24                 .endm
  25
  26                 .macro  load_regs,flags
  27                 ldm\flags       fp, {r1, r2, r4-r9, fp, sp, pc}^
  28                 .endm
  29
  30                 .macro  load1b, reg1
  31                 tst     r9, #0x01
  32 9999:           ldreqbt \reg1, [r0], #1
  33                 ldrneb  \reg1, [r0], #1
  34                 .section __ex_table, "a"
  35                 .align  3
  36                 .long   9999b, 6001f
  37                 .previous
  38                 .endm
  39
  40                 .macro  load2b, reg1, reg2
  41                 tst     r9, #0x01
  42 9999:           ldreqbt \reg1, [r0], #1
  43                 ldrneb  \reg1, [r0], #1
  44 9998:           ldreqbt \reg2, [r0], #1
  45                 ldrneb  \reg2, [r0], #1
  46                 .section __ex_table, "a"
  47                 .long   9999b, 6001f
  48                 .long   9998b, 6001f
  49                 .previous
  50                 .endm
  51
  52                 .macro  load1l, reg1
  53                 tst     r9, #0x01
  54 9999:           ldreqt  \reg1, [r0], #4
  55                 ldrne   \reg1, [r0], #4
  56                 .section __ex_table, "a"
  57                 .align  3
  58                 .long   9999b, 6001f
  59                 .previous
  60                 .endm
  61
  62                 .macro  load2l, reg1, reg2
  63                 tst     r9, #0x01
  64                 ldmneia r0!, {\reg1, \reg2}
  65 9999:           ldreqt  \reg1, [r0], #4
  66 9998:           ldreqt  \reg2, [r0], #4
  67                 .section __ex_table, "a"
  68                 .long   9999b, 6001f
  69                 .long   9998b, 6001f
  70                 .previous
  71                 .endm
  72
  73                 .macro  load4l, reg1, reg2, reg3, reg4
  74                 tst     r9, #0x01
  75                 ldmneia r0!, {\reg1, \reg2, \reg3, \reg4}
  76 9999:           ldreqt  \reg1, [r0], #4
  77 9998:           ldreqt  \reg2, [r0], #4
  78 9997:           ldreqt  \reg3, [r0], #4
  79 9996:           ldreqt  \reg4, [r0], #4
  80                 .section __ex_table, "a"
  81                 .long   9999b, 6001f
  82                 .long   9998b, 6001f
  83                 .long   9997b, 6001f
  84                 .long   9996b, 6001f
  85                 .previous
  86                 .endm
  87
  88 /*
  89  * unsigned int
  90  * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
  91  *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
  92  *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
  93  */
  94
  95 #define FN_ENTRY        ENTRY(csum_partial_copy_from_user)
  96
  97 #include "csumpartialcopygeneric.S"
  98
  99 /*
 100  * FIXME: minor buglet here
 101  * We don't return the checksum for the data present in the buffer.  To do
 102  * so properly, we would have to add in whatever registers were loaded before
 103  * the fault, which, with the current asm above is not predictable.
 104  */
 105                 .align  4
 106 6001:           mov     r4, #-EFAULT
 107                 ldr     r5, [fp, #4]            @ *err_ptr
 108                 str     r4, [r5]
 109                 ldmia   sp, {r1, r2}            @ retrieve dst, len
 110                 add     r2, r2, r1
 111                 mov     r0, #0                  @ zero the buffer
 112 6002:           teq     r2, r1
 113                 strneb  r0, [r1], #1
 114                 bne     6002b
 115                 load_regs       ea