linux/arch/unicore32/lib/copy_to_user.S
GuanXuetao 77c93b2f23 unicore32 additional architecture files: low-level lib: uaccess
This patch implements low-level uaccess libraries.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2011-03-17 09:19:13 +08:00

97 lines
1.8 KiB
ArmAsm

/*
* linux/arch/unicore32/lib/copy_to_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_to_user(void *to, const void *from, size_t n)
*
* Purpose:
*
* copy a block to user memory from kernel memory
*
* Params:
*
* to = user memory
* from = kernel memory
* n = number of bytes to copy
*
* Return value:
*
* Number of bytes NOT copied.
*/
.macro ldr1w ptr reg abort
ldw.w \reg, [\ptr]+, #4
.endm
.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
ldm.w (\reg1, \reg2, \reg3, \reg4), [\ptr]+
.endm
.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
ldm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
.endm
.macro ldr1b ptr reg cond=al abort
notcond \cond, .+8
ldb.w \reg, [\ptr]+, #1
.endm
.macro str1w ptr reg abort
strusr \reg, \ptr, 4, abort=\abort
.endm
.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
100: stm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
.pushsection __ex_table, "a"
.long 100b, \abort
.popsection
.endm
.macro str1b ptr reg cond=al abort
strusr \reg, \ptr, 1, \cond, abort=\abort
.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
WEAK(__copy_to_user)
#include "copy_template.S"
ENDPROC(__copy_to_user)
.pushsection .fixup,"ax"
.align 0
copy_abort_preamble
ldm.w (r1, r2, r3), [sp]+
sub r0, r0, r1
rsub r0, r0, r2
copy_abort_end
.popsection