linux/arch/arm/mm/copypage-v4wb.c
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  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 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 #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

93 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/mm/copypage-v4wb.c
*
* Copyright (C) 1995-1999 Russell King
*/
#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 v4wb_copy_user_page(void *kto, const void *kfrom)
{
int tmp;
asm volatile ("\
.syntax unified\n\
ldmia %1!, {r3, r4, ip, lr} @ 4\n\
1: mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\
stmia %0!, {r3, r4, ip, lr} @ 4\n\
ldmia %1!, {r3, r4, ip, lr} @ 4+1\n\
stmia %0!, {r3, r4, ip, lr} @ 4\n\
ldmia %1!, {r3, r4, ip, lr} @ 4\n\
mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\
stmia %0!, {r3, r4, ip, lr} @ 4\n\
ldmia %1!, {r3, r4, ip, lr} @ 4\n\
subs %2, %2, #1 @ 1\n\
stmia %0!, {r3, r4, ip, lr} @ 4\n\
ldmiane %1!, {r3, r4, ip, lr} @ 4\n\
bne 1b @ 1\n\
mcr p15, 0, %1, c7, c10, 4 @ 1 drain WB"
: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
: "2" (PAGE_SIZE / 64)
: "r3", "r4", "ip", "lr");
}
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,
};