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/asm-offsets.h>
  17
  18                 .text
  19
  20 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
  21                 .macro  save_regs
  22                 mrc     p15, 0, ip, c3, c0, 0
  23                 stmfd   sp!, {r1, r2, r4 - r8, ip, lr}
  24                 uaccess_enable ip
  25                 .endm
  26
  27                 .macro  load_regs
  28                 ldmfd   sp!, {r1, r2, r4 - r8, ip, lr}
  29                 mcr     p15, 0, ip, c3, c0, 0
  30                 ret     lr
  31                 .endm
  32 #else
  33                 .macro  save_regs
  34                 stmfd   sp!, {r1, r2, r4 - r8, lr}
  35                 .endm
  36
  37                 .macro  load_regs
  38                 ldmfd   sp!, {r1, r2, r4 - r8, pc}
  39                 .endm
  40 #endif
  41
  42                 .macro  load1b, reg1
  43                 ldrusr  \reg1, r0, 1
  44                 .endm
  45
  46                 .macro  load2b, reg1, reg2
  47                 ldrusr  \reg1, r0, 1
  48                 ldrusr  \reg2, r0, 1
  49                 .endm
  50
  51                 .macro  load1l, reg1
  52                 ldrusr  \reg1, r0, 4
  53                 .endm
  54
  55                 .macro  load2l, reg1, reg2
  56                 ldrusr  \reg1, r0, 4
  57                 ldrusr  \reg2, r0, 4
  58                 .endm
  59
  60                 .macro  load4l, reg1, reg2, reg3, reg4
  61                 ldrusr  \reg1, r0, 4
  62                 ldrusr  \reg2, r0, 4
  63                 ldrusr  \reg3, r0, 4
  64                 ldrusr  \reg4, r0, 4
  65                 .endm
  66
  67 /*
  68  * unsigned int
  69  * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
  70  *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
  71  *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
  72  */
  73
  74 #define FN_ENTRY        ENTRY(csum_partial_copy_from_user)
  75 #define FN_EXIT         ENDPROC(csum_partial_copy_from_user)
  76
  77 #include "csumpartialcopygeneric.S"
  78
  79 /*
  80  * FIXME: minor buglet here
  81  * We don't return the checksum for the data present in the buffer.  To do
  82  * so properly, we would have to add in whatever registers were loaded before
  83  * the fault, which, with the current asm above is not predictable.
  84  */
  85                 .pushsection .text.fixup,"ax"
  86                 .align  4
  87 9001:           mov     r4, #-EFAULT
  88                 ldr     r5, [sp, #8*4]          @ *err_ptr
  89                 str     r4, [r5]
  90                 ldmia   sp, {r1, r2}            @ retrieve dst, len
  91                 add     r2, r2, r1
  92                 mov     r0, #0                  @ zero the buffer
  93 9002:           teq     r2, r1
  94                 strneb  r0, [r1], #1
  95                 bne     9002b
  96                 load_regs
  97                 .popsection