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/*
* linux/arch/arm/lib/copypage.S
*
* Copyright (C) 1995-1999 Russell King
*
* 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.
*
* ASM optimised string functions
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/asm-offsets.h>
.text
.align 5
/*
* ARMv4 optimised copy_user_page
*
* We flush the destination cache lines just before we write the data into the
* corresponding address. Since the Dcache is read-allocate, this removes the
* Dcache aliasing issue. The writes will be forwarded to the write buffer,
* and merged as appropriate.
*
* Note: We rely on all ARMv4 processors implementing the "invalidate D line"
* instruction. If your processor does not supply this, you have to write your
* own copy_user_page that does the right thing.
*/
ENTRY(v4wb_copy_user_page)
stmfd sp!, {r4, lr} @ 2
mov r2, #PAGE_SZ/64 @ 1
ldmia r1!, {r3, r4, ip, lr} @ 4
1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
stmia r0!, {r3, r4, ip, lr} @ 4
ldmia r1!, {r3, r4, ip, lr} @ 4+1
stmia r0!, {r3, r4, ip, lr} @ 4
ldmia r1!, {r3, r4, ip, lr} @ 4
mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
stmia r0!, {r3, r4, ip, lr} @ 4
ldmia r1!, {r3, r4, ip, lr} @ 4
subs r2, r2, #1 @ 1
stmia r0!, {r3, r4, ip, lr} @ 4
ldmneia r1!, {r3, r4, ip, lr} @ 4
bne 1b @ 1
mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB
ldmfd sp!, {r4, pc} @ 3
.align 5
/*
* ARMv4 optimised clear_user_page
*
* Same story as above.
*/
ENTRY(v4wb_clear_user_page)
str lr, [sp, #-4]!
mov r1, #PAGE_SZ/64 @ 1
mov r2, #0 @ 1
mov r3, #0 @ 1
mov ip, #0 @ 1
mov lr, #0 @ 1
1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
stmia r0!, {r2, r3, ip, lr} @ 4
stmia r0!, {r2, r3, ip, lr} @ 4
mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line
stmia r0!, {r2, r3, ip, lr} @ 4
stmia r0!, {r2, r3, ip, lr} @ 4
subs r1, r1, #1 @ 1
bne 1b @ 1
mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB
ldr pc, [sp], #4
__INITDATA
.type v4wb_user_fns, #object
ENTRY(v4wb_user_fns)
.long v4wb_clear_user_page
.long v4wb_copy_user_page
.size v4wb_user_fns, . - v4wb_user_fns
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