forked from Minki/linux
142 lines
2.5 KiB
ArmAsm
142 lines
2.5 KiB
ArmAsm
|
/*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation; either version 2 of the License, or
|
||
|
|
* (at your option) any later version.
|
||
|
|
*
|
||
|
|
* This program is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with this program; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
||
|
|
*
|
||
|
|
* Copyright (C) IBM Corporation, 2012
|
||
|
|
*
|
||
|
|
* Author: Anton Blanchard <anton@au.ibm.com>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <asm/ppc_asm.h>
|
||
|
|
|
||
|
|
/**
|
||
|
|
* __clear_user: - Zero a block of memory in user space, with less checking.
|
||
|
|
* @to: Destination address, in user space.
|
||
|
|
* @n: Number of bytes to zero.
|
||
|
|
*
|
||
|
|
* Zero a block of memory in user space. Caller must check
|
||
|
|
* the specified block with access_ok() before calling this function.
|
||
|
|
*
|
||
|
|
* Returns number of bytes that could not be cleared.
|
||
|
|
* On success, this will be zero.
|
||
|
|
*/
|
||
|
|
|
||
|
|
.macro err1
|
||
|
|
100:
|
||
|
|
.section __ex_table,"a"
|
||
|
|
.align 3
|
||
|
|
.llong 100b,.Ldo_err1
|
||
|
|
.previous
|
||
|
|
.endm
|
||
|
|
|
||
|
|
.macro err2
|
||
|
|
200:
|
||
|
|
.section __ex_table,"a"
|
||
|
|
.align 3
|
||
|
|
.llong 200b,.Ldo_err2
|
||
|
|
.previous
|
||
|
|
.endm
|
||
|
|
|
||
|
|
.macro err3
|
||
|
|
300:
|
||
|
|
.section __ex_table,"a"
|
||
|
|
.align 3
|
||
|
|
.llong 300b,.Ldo_err3
|
||
|
|
.previous
|
||
|
|
.endm
|
||
|
|
|
||
|
|
.Ldo_err1:
|
||
|
|
mr r3,r8
|
||
|
|
|
||
|
|
.Ldo_err2:
|
||
|
|
mtctr r4
|
||
|
|
1:
|
||
|
|
err3; stb r0,0(r3)
|
||
|
|
addi r3,r3,1
|
||
|
|
addi r4,r4,-1
|
||
|
|
bdnz 1b
|
||
|
|
|
||
|
|
.Ldo_err3:
|
||
|
|
mr r3,r4
|
||
|
|
blr
|
||
|
|
|
||
|
|
_GLOBAL(__clear_user)
|
||
|
|
cmpdi r4,32
|
||
|
|
neg r6,r3
|
||
|
|
li r0,0
|
||
|
|
blt .Lshort_clear
|
||
|
|
mr r8,r3
|
||
|
|
mtocrf 0x01,r6
|
||
|
|
clrldi r6,r6,(64-3)
|
||
|
|
|
||
|
|
/* Get the destination 8 byte aligned */
|
||
|
|
bf cr7*4+3,1f
|
||
|
|
err1; stb r0,0(r3)
|
||
|
|
addi r3,r3,1
|
||
|
|
|
||
|
|
1: bf cr7*4+2,2f
|
||
|
|
err1; sth r0,0(r3)
|
||
|
|
addi r3,r3,2
|
||
|
|
|
||
|
|
2: bf cr7*4+1,3f
|
||
|
|
err1; stw r0,0(r3)
|
||
|
|
addi r3,r3,4
|
||
|
|
|
||
|
|
3: sub r4,r4,r6
|
||
|
|
srdi r6,r4,5
|
||
|
|
cmpdi r4,32
|
||
|
|
blt .Lshort_clear
|
||
|
|
mtctr r6
|
||
|
|
|
||
|
|
/* Do 32 byte chunks */
|
||
|
|
4:
|
||
|
|
err2; std r0,0(r3)
|
||
|
|
err2; std r0,8(r3)
|
||
|
|
err2; std r0,16(r3)
|
||
|
|
err2; std r0,24(r3)
|
||
|
|
addi r3,r3,32
|
||
|
|
addi r4,r4,-32
|
||
|
|
bdnz 4b
|
||
|
|
|
||
|
|
.Lshort_clear:
|
||
|
|
/* up to 31 bytes to go */
|
||
|
|
cmpdi r4,16
|
||
|
|
blt 6f
|
||
|
|
err2; std r0,0(r3)
|
||
|
|
err2; std r0,8(r3)
|
||
|
|
addi r3,r3,16
|
||
|
|
addi r4,r4,-16
|
||
|
|
|
||
|
|
/* Up to 15 bytes to go */
|
||
|
|
6: mr r8,r3
|
||
|
|
clrldi r4,r4,(64-4)
|
||
|
|
mtocrf 0x01,r4
|
||
|
|
bf cr7*4+0,7f
|
||
|
|
err1; std r0,0(r3)
|
||
|
|
addi r3,r3,8
|
||
|
|
|
||
|
|
7: bf cr7*4+1,8f
|
||
|
|
err1; stw r0,0(r3)
|
||
|
|
addi r3,r3,4
|
||
|
|
|
||
|
|
8: bf cr7*4+2,9f
|
||
|
|
err1; sth r0,0(r3)
|
||
|
|
addi r3,r3,2
|
||
|
|
|
||
|
|
9: bf cr7*4+3,10f
|
||
|
|
err1; stb r0,0(r3)
|
||
|
|
|
||
|
|
10: li r3,0
|
||
|
|
blr
|