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/*
* linux/arch/arm/lib/copypage-xscale.S
*
* Copyright (C) 2001 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.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/constants.h>
/*
* General note:
* We don't really want write-allocate cache behaviour for these functions
* since that will just eat through 8K of the cache.
*/
.text
.align 5
/*
* XScale optimised copy_user_page
* r0 = destination
* r1 = source
* r2 = virtual user address of ultimate destination page
*
* The source page may have some clean entries in the cache already, but we
* can safely ignore them - break_cow() will flush them out of the cache
* if we eventually end up using our copied page.
*
* What we could do is use the mini-cache to buffer reads from the source
* page. We rely on the mini-cache being smaller than one page, so we'll
* cycle through the complete cache anyway.
*/
ENTRY(xscale_mc_copy_user_page)
stmfd sp!, {r4, r5, lr}
mov r5, r0
mov r0, r1
bl map_page_minicache
mov r1, r5
mov lr, #PAGE_SZ/64-1
/*
* Strangely enough, best performance is achieved
* when prefetching destination as well. (NP)
*/
pld [r0, #0]
pld [r0, #32]
pld [r1, #0]
pld [r1, #32]
1: pld [r0, #64]
pld [r0, #96]
pld [r1, #64]
pld [r1, #96]
2: ldrd r2, [r0], #8
ldrd r4, [r0], #8
mov ip, r1
strd r2, [r1], #8
ldrd r2, [r0], #8
strd r4, [r1], #8
ldrd r4, [r0], #8
strd r2, [r1], #8
strd r4, [r1], #8
mcr p15, 0, ip, c7, c10, 1 @ clean D line
ldrd r2, [r0], #8
mcr p15, 0, ip, c7, c6, 1 @ invalidate D line
ldrd r4, [r0], #8
mov ip, r1
strd r2, [r1], #8
ldrd r2, [r0], #8
strd r4, [r1], #8
ldrd r4, [r0], #8
strd r2, [r1], #8
strd r4, [r1], #8
mcr p15, 0, ip, c7, c10, 1 @ clean D line
subs lr, lr, #1
mcr p15, 0, ip, c7, c6, 1 @ invalidate D line
bgt 1b
beq 2b
ldmfd sp!, {r4, r5, pc}
.align 5
/*
* XScale optimised clear_user_page
* r0 = destination
* r1 = virtual user address of ultimate destination page
*/
ENTRY(xscale_mc_clear_user_page)
mov r1, #PAGE_SZ/32
mov r2, #0
mov r3, #0
1: mov ip, r0
strd r2, [r0], #8
strd r2, [r0], #8
strd r2, [r0], #8
strd r2, [r0], #8
mcr p15, 0, ip, c7, c10, 1 @ clean D line
subs r1, r1, #1
mcr p15, 0, ip, c7, c6, 1 @ invalidate D line
bne 1b
mov pc, lr
__INITDATA
.type xscale_mc_user_fns, #object
ENTRY(xscale_mc_user_fns)
.long xscale_mc_clear_user_page
.long xscale_mc_copy_user_page
.size xscale_mc_user_fns, . - xscale_mc_user_fns
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