xref: /OK3568_Linux_fs/kernel/arch/arm64/mm/copypage.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Based on arch/arm/mm/copypage.c
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved.
6*4882a593Smuzhiyun  * Copyright (C) 2012 ARM Ltd.
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun #include <linux/bitops.h>
10*4882a593Smuzhiyun #include <linux/mm.h>
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include <asm/page.h>
13*4882a593Smuzhiyun #include <asm/cacheflush.h>
14*4882a593Smuzhiyun #include <asm/cpufeature.h>
15*4882a593Smuzhiyun #include <asm/mte.h>
16*4882a593Smuzhiyun 
copy_highpage(struct page * to,struct page * from)17*4882a593Smuzhiyun void copy_highpage(struct page *to, struct page *from)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun 	void *kto = page_address(to);
20*4882a593Smuzhiyun 	void *kfrom = page_address(from);
21*4882a593Smuzhiyun 
22*4882a593Smuzhiyun 	copy_page(kto, kfrom);
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun 	if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
25*4882a593Smuzhiyun 		set_bit(PG_mte_tagged, &to->flags);
26*4882a593Smuzhiyun 		page_kasan_tag_reset(to);
27*4882a593Smuzhiyun 		/*
28*4882a593Smuzhiyun 		 * We need smp_wmb() in between setting the flags and clearing the
29*4882a593Smuzhiyun 		 * tags because if another thread reads page->flags and builds a
30*4882a593Smuzhiyun 		 * tagged address out of it, there is an actual dependency to the
31*4882a593Smuzhiyun 		 * memory access, but on the current thread we do not guarantee that
32*4882a593Smuzhiyun 		 * the new page->flags are visible before the tags were updated.
33*4882a593Smuzhiyun 		 */
34*4882a593Smuzhiyun 		smp_wmb();
35*4882a593Smuzhiyun 		mte_copy_page_tags(kto, kfrom);
36*4882a593Smuzhiyun 	}
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun EXPORT_SYMBOL(copy_highpage);
39*4882a593Smuzhiyun 
copy_user_highpage(struct page * to,struct page * from,unsigned long vaddr,struct vm_area_struct * vma)40*4882a593Smuzhiyun void copy_user_highpage(struct page *to, struct page *from,
41*4882a593Smuzhiyun 			unsigned long vaddr, struct vm_area_struct *vma)
42*4882a593Smuzhiyun {
43*4882a593Smuzhiyun 	copy_highpage(to, from);
44*4882a593Smuzhiyun 	flush_dcache_page(to);
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(copy_user_highpage);
47