mirror of
https://github.com/torvalds/linux.git
synced 2024-11-01 09:41:44 +00:00
89 lines
2.3 KiB
C
89 lines
2.3 KiB
C
/*
|
|
* linux/arch/arm/mm/copypage-v4wt.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.
|
|
*
|
|
* This is for CPUs with a writethrough cache and 'flush ID cache' is
|
|
* the only supported cache operation.
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/highmem.h>
|
|
|
|
/*
|
|
* ARMv4 optimised copy_user_highpage
|
|
*
|
|
* Since we have writethrough caches, we don't have to worry about
|
|
* dirty data in the cache. However, we do have to ensure that
|
|
* subsequent reads are up to date.
|
|
*/
|
|
static void __naked
|
|
v4wt_copy_user_page(void *kto, const void *kfrom)
|
|
{
|
|
asm("\
|
|
stmfd sp!, {r4, lr} @ 2\n\
|
|
mov r2, %2 @ 1\n\
|
|
ldmia r1!, {r3, r4, ip, lr} @ 4\n\
|
|
1: stmia r0!, {r3, r4, ip, lr} @ 4\n\
|
|
ldmia r1!, {r3, r4, ip, lr} @ 4+1\n\
|
|
stmia r0!, {r3, r4, ip, lr} @ 4\n\
|
|
ldmia r1!, {r3, r4, ip, lr} @ 4\n\
|
|
stmia r0!, {r3, r4, ip, lr} @ 4\n\
|
|
ldmia r1!, {r3, r4, ip, lr} @ 4\n\
|
|
subs r2, r2, #1 @ 1\n\
|
|
stmia r0!, {r3, r4, ip, lr} @ 4\n\
|
|
ldmneia r1!, {r3, r4, ip, lr} @ 4\n\
|
|
bne 1b @ 1\n\
|
|
mcr p15, 0, r2, c7, c7, 0 @ flush ID cache\n\
|
|
ldmfd sp!, {r4, pc} @ 3"
|
|
:
|
|
: "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64));
|
|
}
|
|
|
|
void v4wt_copy_user_highpage(struct page *to, struct page *from,
|
|
unsigned long vaddr, struct vm_area_struct *vma)
|
|
{
|
|
void *kto, *kfrom;
|
|
|
|
kto = kmap_atomic(to);
|
|
kfrom = kmap_atomic(from);
|
|
v4wt_copy_user_page(kto, kfrom);
|
|
kunmap_atomic(kfrom);
|
|
kunmap_atomic(kto);
|
|
}
|
|
|
|
/*
|
|
* ARMv4 optimised clear_user_page
|
|
*
|
|
* Same story as above.
|
|
*/
|
|
void v4wt_clear_user_highpage(struct page *page, unsigned long vaddr)
|
|
{
|
|
void *ptr, *kaddr = kmap_atomic(page);
|
|
asm volatile("\
|
|
mov r1, %2 @ 1\n\
|
|
mov r2, #0 @ 1\n\
|
|
mov r3, #0 @ 1\n\
|
|
mov ip, #0 @ 1\n\
|
|
mov lr, #0 @ 1\n\
|
|
1: stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
subs r1, r1, #1 @ 1\n\
|
|
bne 1b @ 1\n\
|
|
mcr p15, 0, r2, c7, c7, 0 @ flush ID cache"
|
|
: "=r" (ptr)
|
|
: "0" (kaddr), "I" (PAGE_SIZE / 64)
|
|
: "r1", "r2", "r3", "ip", "lr");
|
|
kunmap_atomic(kaddr);
|
|
}
|
|
|
|
struct cpu_user_fns v4wt_user_fns __initdata = {
|
|
.cpu_clear_user_highpage = v4wt_clear_user_highpage,
|
|
.cpu_copy_user_highpage = v4wt_copy_user_highpage,
|
|
};
|