Linux kernel mirror (for testing)
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linux
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
17void copy_highpage(struct page *to, struct page *from)
18{
19 void *kto = page_address(to);
20 void *kfrom = page_address(from);
21 struct folio *src = page_folio(from);
22 struct folio *dst = page_folio(to);
23 unsigned int i, nr_pages;
24
25 copy_page(kto, kfrom);
26
27 if (kasan_hw_tags_enabled())
28 page_kasan_tag_reset(to);
29
30 if (!system_supports_mte())
31 return;
32
33 if (folio_test_hugetlb(src)) {
34 if (!folio_test_hugetlb_mte_tagged(src) ||
35 from != folio_page(src, 0))
36 return;
37
38 folio_try_hugetlb_mte_tagging(dst);
39
40 /*
41 * Populate tags for all subpages.
42 *
43 * Don't assume the first page is head page since
44 * huge page copy may start from any subpage.
45 */
46 nr_pages = folio_nr_pages(src);
47 for (i = 0; i < nr_pages; i++) {
48 kfrom = page_address(folio_page(src, i));
49 kto = page_address(folio_page(dst, i));
50 mte_copy_page_tags(kto, kfrom);
51 }
52 folio_set_hugetlb_mte_tagged(dst);
53 } else if (page_mte_tagged(from)) {
54 /*
55 * Most of the time it's a new page that shouldn't have been
56 * tagged yet. However, folio migration can end up reusing the
57 * same page without untagging it. Ignore the warning if the
58 * page is already tagged.
59 */
60 try_page_mte_tagging(to);
61
62 mte_copy_page_tags(kto, kfrom);
63 set_page_mte_tagged(to);
64 }
65}
66EXPORT_SYMBOL(copy_highpage);
67
68void copy_user_highpage(struct page *to, struct page *from,
69 unsigned long vaddr, struct vm_area_struct *vma)
70{
71 copy_highpage(to, from);
72 flush_dcache_page(to);
73}
74EXPORT_SYMBOL_GPL(copy_user_highpage);