root/arch/unicore32/lib/copy_from_user.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * linux/arch/unicore32/lib/copy_from_user.S
   4  *
   5  * Code specific to PKUnity SoC and UniCore ISA
   6  *
   7  * Copyright (C) 2001-2010 GUAN Xue-tao
   8  */
   9 
  10 #include <linux/linkage.h>
  11 #include <asm/assembler.h>
  12 
  13 /*
  14  * Prototype:
  15  *
  16  *      size_t raw_copy_from_user(void *to, const void *from, size_t n)
  17  *
  18  * Purpose:
  19  *
  20  *      copy a block to kernel memory from user memory
  21  *
  22  * Params:
  23  *
  24  *      to = kernel memory
  25  *      from = user memory
  26  *      n = number of bytes to copy
  27  *
  28  * Return value:
  29  *
  30  *      Number of bytes NOT copied.
  31  */
  32 
  33         .macro ldr1w ptr reg abort
  34         ldrusr  \reg, \ptr, 4, abort=\abort
  35         .endm
  36 
  37         .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
  38 100:    ldm.w   (\reg1, \reg2, \reg3, \reg4), [\ptr]+
  39         .pushsection __ex_table, "a"
  40         .align  3
  41         .long 100b, \abort
  42         .popsection
  43         .endm
  44 
  45         .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
  46 100:    ldm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
  47         .pushsection __ex_table, "a"
  48         .align  3
  49         .long 100b, \abort
  50         .popsection
  51         .endm
  52 
  53         .macro ldr1b ptr reg cond=al abort
  54         ldrusr  \reg, \ptr, 1, \cond, abort=\abort
  55         .endm
  56 
  57         .macro str1w ptr reg abort
  58         stw.w \reg, [\ptr]+, #4
  59         .endm
  60 
  61         .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
  62         stm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
  63         .endm
  64 
  65         .macro str1b ptr reg cond=al abort
  66         .ifnc   \cond, al
  67         b\cond  201f
  68         b       202f
  69         .endif
  70 201:    stb.w \reg, [\ptr]+, #1
  71 202:
  72         .endm
  73 
  74         .macro enter
  75         mov     r3, #0
  76         stm.w   (r0, r2, r3), [sp-]
  77         .endm
  78 
  79         .macro exit
  80         add     sp, sp, #8
  81         ldm.w   (r0), [sp]+
  82         mov     pc, lr
  83         .endm
  84 
  85         .text
  86 
  87 ENTRY(raw_copy_from_user)
  88 
  89 #include "copy_template.S"
  90 
  91 ENDPROC(raw_copy_from_user)
  92 
  93         .pushsection .fixup,"ax"
  94         .align 0
  95         copy_abort_preamble
  96         ldm.w   (r1, r2, r3), [sp]+
  97         sub     r0, r0, r1
  98         rsub    r0, r0, r2
  99         copy_abort_end
 100         .popsection
 101