1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Based on arch/arm/mm/copypage.c
4 *
5 * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved.
6 * Copyright (C) 2012 ARM Ltd.
7 */
8
9 #include <linux/bitops.h>
10 #include <linux/mm.h>
11
12 #include <asm/page.h>
13 #include <asm/cacheflush.h>
14 #include <asm/cpufeature.h>
15 #include <asm/mte.h>
16
copy_highpage(struct page * to,struct page * from)17 void copy_highpage(struct page *to, struct page *from)
18 {
19 void *kto = page_address(to);
20 void *kfrom = page_address(from);
21
22 copy_page(kto, kfrom);
23
24 if (kasan_hw_tags_enabled())
25 page_kasan_tag_reset(to);
26
27 if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
28 set_bit(PG_mte_tagged, &to->flags);
29 /*
30 * We need smp_wmb() in between setting the flags and clearing the
31 * tags because if another thread reads page->flags and builds a
32 * tagged address out of it, there is an actual dependency to the
33 * memory access, but on the current thread we do not guarantee that
34 * the new page->flags are visible before the tags were updated.
35 */
36 smp_wmb();
37 mte_copy_page_tags(kto, kfrom);
38 }
39 }
40 EXPORT_SYMBOL(copy_highpage);
41
copy_user_highpage(struct page * to,struct page * from,unsigned long vaddr,struct vm_area_struct * vma)42 void copy_user_highpage(struct page *to, struct page *from,
43 unsigned long vaddr, struct vm_area_struct *vma)
44 {
45 copy_highpage(to, from);
46 flush_dcache_page(to);
47 }
48 EXPORT_SYMBOL_GPL(copy_user_highpage);
49