From 25c17c4b55def92a01e3eecc9c775a6ee25ca20f Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Tue, 1 Oct 2024 15:52:19 -0700 Subject: hugetlb: arm64: add mte support Enable MTE support for hugetlb. The MTE page flags will be set on the folio only. When copying hugetlb folio (for example, CoW), the tags for all subpages will be copied when copying the first subpage. When freeing hugetlb folio, the MTE flags will be cleared. Reviewed-by: Catalin Marinas Reviewed-by: David Hildenbrand Signed-off-by: Yang Shi Link: https://lore.kernel.org/r/20241001225220.271178-1-yang@os.amperecomputing.com Signed-off-by: Catalin Marinas --- arch/arm64/mm/copypage.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) (limited to 'arch/arm64/mm') diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c index a7bb20055ce0..87b3f1a25535 100644 --- a/arch/arm64/mm/copypage.c +++ b/arch/arm64/mm/copypage.c @@ -18,15 +18,40 @@ void copy_highpage(struct page *to, struct page *from) { void *kto = page_address(to); void *kfrom = page_address(from); + struct folio *src = page_folio(from); + struct folio *dst = page_folio(to); + unsigned int i, nr_pages; copy_page(kto, kfrom); if (kasan_hw_tags_enabled()) page_kasan_tag_reset(to); - if (system_supports_mte() && page_mte_tagged(from)) { + if (!system_supports_mte()) + return; + + if (folio_test_hugetlb(src) && + folio_test_hugetlb_mte_tagged(src)) { + if (!folio_try_hugetlb_mte_tagging(dst)) + return; + + /* + * Populate tags for all subpages. + * + * Don't assume the first page is head page since + * huge page copy may start from any subpage. + */ + nr_pages = folio_nr_pages(src); + for (i = 0; i < nr_pages; i++) { + kfrom = page_address(folio_page(src, i)); + kto = page_address(folio_page(dst, i)); + mte_copy_page_tags(kto, kfrom); + } + folio_set_hugetlb_mte_tagged(dst); + } else if (page_mte_tagged(from)) { /* It's a new page, shouldn't have been tagged yet */ WARN_ON_ONCE(!try_page_mte_tagging(to)); + mte_copy_page_tags(kto, kfrom); set_page_mte_tagged(to); } -- cgit v1.2.3