| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Based on arch/arm/mm/copypage.c |
| * |
| * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved. |
| * Copyright (C) 2012 ARM Ltd. |
| */ |
| |
| #include <linux/bitops.h> |
| #include <linux/mm.h> |
| |
| #include <asm/page.h> |
| #include <asm/cacheflush.h> |
| #include <asm/cpufeature.h> |
| #include <asm/mte.h> |
| |
| void copy_highpage(struct page *to, struct page *from) |
| { |
| void *kto = page_address(to); |
| void *kfrom = page_address(from); |
| |
| copy_page(kto, kfrom); |
| |
| if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) { |
| set_bit(PG_mte_tagged, &to->flags); |
| page_kasan_tag_reset(to); |
| /* |
| * We need smp_wmb() in between setting the flags and clearing the |
| * tags because if another thread reads page->flags and builds a |
| * tagged address out of it, there is an actual dependency to the |
| * memory access, but on the current thread we do not guarantee that |
| * the new page->flags are visible before the tags were updated. |
| */ |
| smp_wmb(); |
| mte_copy_page_tags(kto, kfrom); |
| } |
| } |
| EXPORT_SYMBOL(copy_highpage); |
| |
| void copy_user_highpage(struct page *to, struct page *from, |
| unsigned long vaddr, struct vm_area_struct *vma) |
| { |
| copy_highpage(to, from); |
| flush_dcache_page(to); |
| } |
| EXPORT_SYMBOL_GPL(copy_user_highpage); |