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 17 void 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 } 66 EXPORT_SYMBOL(copy_highpage); 67 68 void 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 } 74 EXPORT_SYMBOL_GPL(copy_user_highpage); 75