mirror of https://gitee.com/openkylin/linux.git
112 lines
2.3 KiB
ArmAsm
112 lines
2.3 KiB
ArmAsm
/*
|
|
* This file contains miscellaneous low-level functions.
|
|
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
|
|
*
|
|
* Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
|
|
* and Paul Mackerras.
|
|
*
|
|
* A couple of functions stolen from arch/ppc/kernel/misc.S for UML
|
|
* by Chris Emerson.
|
|
*
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#include <asm/processor.h>
|
|
#include "ppc_asm.h"
|
|
|
|
#if defined(CONFIG_4xx) || defined(CONFIG_8xx)
|
|
#define CACHE_LINE_SIZE 16
|
|
#define LG_CACHE_LINE_SIZE 4
|
|
#define MAX_COPY_PREFETCH 1
|
|
#else
|
|
#define CACHE_LINE_SIZE 32
|
|
#define LG_CACHE_LINE_SIZE 5
|
|
#define MAX_COPY_PREFETCH 4
|
|
#endif /* CONFIG_4xx || CONFIG_8xx */
|
|
|
|
.text
|
|
|
|
/*
|
|
* Clear a page using the dcbz instruction, which doesn't cause any
|
|
* memory traffic (except to write out any cache lines which get
|
|
* displaced). This only works on cacheable memory.
|
|
*/
|
|
_GLOBAL(clear_page)
|
|
li r0,4096/CACHE_LINE_SIZE
|
|
mtctr r0
|
|
#ifdef CONFIG_8xx
|
|
li r4, 0
|
|
1: stw r4, 0(r3)
|
|
stw r4, 4(r3)
|
|
stw r4, 8(r3)
|
|
stw r4, 12(r3)
|
|
#else
|
|
1: dcbz 0,r3
|
|
#endif
|
|
addi r3,r3,CACHE_LINE_SIZE
|
|
bdnz 1b
|
|
blr
|
|
|
|
/*
|
|
* Copy a whole page. We use the dcbz instruction on the destination
|
|
* to reduce memory traffic (it eliminates the unnecessary reads of
|
|
* the destination into cache). This requires that the destination
|
|
* is cacheable.
|
|
*/
|
|
#define COPY_16_BYTES \
|
|
lwz r6,4(r4); \
|
|
lwz r7,8(r4); \
|
|
lwz r8,12(r4); \
|
|
lwzu r9,16(r4); \
|
|
stw r6,4(r3); \
|
|
stw r7,8(r3); \
|
|
stw r8,12(r3); \
|
|
stwu r9,16(r3)
|
|
|
|
_GLOBAL(copy_page)
|
|
addi r3,r3,-4
|
|
addi r4,r4,-4
|
|
li r5,4
|
|
|
|
#ifndef CONFIG_8xx
|
|
#if MAX_COPY_PREFETCH > 1
|
|
li r0,MAX_COPY_PREFETCH
|
|
li r11,4
|
|
mtctr r0
|
|
11: dcbt r11,r4
|
|
addi r11,r11,CACHE_LINE_SIZE
|
|
bdnz 11b
|
|
#else /* MAX_COPY_PREFETCH == 1 */
|
|
dcbt r5,r4
|
|
li r11,CACHE_LINE_SIZE+4
|
|
#endif /* MAX_COPY_PREFETCH */
|
|
#endif /* CONFIG_8xx */
|
|
|
|
li r0,4096/CACHE_LINE_SIZE
|
|
mtctr r0
|
|
1:
|
|
#ifndef CONFIG_8xx
|
|
dcbt r11,r4
|
|
dcbz r5,r3
|
|
#endif
|
|
COPY_16_BYTES
|
|
#if CACHE_LINE_SIZE >= 32
|
|
COPY_16_BYTES
|
|
#if CACHE_LINE_SIZE >= 64
|
|
COPY_16_BYTES
|
|
COPY_16_BYTES
|
|
#if CACHE_LINE_SIZE >= 128
|
|
COPY_16_BYTES
|
|
COPY_16_BYTES
|
|
COPY_16_BYTES
|
|
COPY_16_BYTES
|
|
#endif
|
|
#endif
|
|
#endif
|
|
bdnz 1b
|
|
blr
|