linux/arch/unicore32/lib/copy_from_user.S

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/*
* linux/arch/unicore32/lib/copy_from_user.S
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
/*
* Prototype:
*
* size_t __copy_from_user(void *to, const void *from, size_t n)
*
* Purpose:
*
* copy a block to kernel memory from user memory
*
* Params:
*
* to = kernel memory
* from = user memory
* n = number of bytes to copy
*
* Return value:
*
* Number of bytes NOT copied.
*/
.macro ldr1w ptr reg abort
ldrusr \reg, \ptr, 4, abort=\abort
.endm
.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
100: ldm.w (\reg1, \reg2, \reg3, \reg4), [\ptr]+
.pushsection __ex_table, "a"
.align 3
.long 100b, \abort
.popsection
.endm
.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
100: ldm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
.pushsection __ex_table, "a"
.align 3
.long 100b, \abort
.popsection
.endm
.macro ldr1b ptr reg cond=al abort
ldrusr \reg, \ptr, 1, \cond, abort=\abort
.endm
.macro str1w ptr reg abort
stw.w \reg, [\ptr]+, #4
.endm
.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
stm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
.endm
.macro str1b ptr reg cond=al abort
.ifnc \cond, al
b\cond 201f
b 202f
.endif
201: stb.w \reg, [\ptr]+, #1
202:
.endm
.macro enter
mov r3, #0
stm.w (r0, r2, r3), [sp-]
.endm
.macro exit
add sp, sp, #8
ldm.w (r0), [sp]+
mov pc, lr
.endm
.text
ENTRY(__copy_from_user)
#include "copy_template.S"
ENDPROC(__copy_from_user)
.pushsection .fixup,"ax"
.align 0
copy_abort_preamble
ldm.w (r1, r2), [sp]+
sub r3, r0, r1
rsub r2, r3, r2
stw r2, [sp]
mov r1, #0
b.l memset
ldw.w r0, [sp]+, #4
copy_abort_end
.popsection