mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 18:11:56 +00:00
96 lines
2.8 KiB
C
96 lines
2.8 KiB
C
/*
|
|
* linux/arch/arm/mm/copypage-v4wb.c
|
|
*
|
|
* 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.
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/highmem.h>
|
|
|
|
/*
|
|
* ARMv4 optimised copy_user_highpage
|
|
*
|
|
* 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_highpage that does the right thing.
|
|
*/
|
|
static void __naked
|
|
v4wb_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: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\
|
|
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\
|
|
mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\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, r1, c7, c10, 4 @ 1 drain WB\n\
|
|
ldmfd sp!, {r4, pc} @ 3"
|
|
:
|
|
: "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64));
|
|
}
|
|
|
|
void v4wb_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);
|
|
flush_cache_page(vma, vaddr, page_to_pfn(from));
|
|
v4wb_copy_user_page(kto, kfrom);
|
|
kunmap_atomic(kfrom);
|
|
kunmap_atomic(kto);
|
|
}
|
|
|
|
/*
|
|
* ARMv4 optimised clear_user_page
|
|
*
|
|
* Same story as above.
|
|
*/
|
|
void v4wb_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: mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
stmia %0!, {r2, r3, ip, lr} @ 4\n\
|
|
mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\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, r1, c7, c10, 4 @ 1 drain WB"
|
|
: "=r" (ptr)
|
|
: "0" (kaddr), "I" (PAGE_SIZE / 64)
|
|
: "r1", "r2", "r3", "ip", "lr");
|
|
kunmap_atomic(kaddr);
|
|
}
|
|
|
|
struct cpu_user_fns v4wb_user_fns __initdata = {
|
|
.cpu_clear_user_highpage = v4wb_clear_user_highpage,
|
|
.cpu_copy_user_highpage = v4wb_copy_user_highpage,
|
|
};
|