// 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);
        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())
                return;

        if (folio_test_hugetlb(src)) {
                if (!folio_test_hugetlb_mte_tagged(src) ||
                    from != folio_page(src, 0))
                        return;

                folio_try_hugetlb_mte_tagging(dst);

                /*
                 * 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)) {
                /*
                 * Most of the time it's a new page that shouldn't have been
                 * tagged yet. However, folio migration can end up reusing the
                 * same page without untagging it. Ignore the warning if the
                 * page is already tagged.
                 */
                try_page_mte_tagging(to);

                mte_copy_page_tags(kto, kfrom);
                set_page_mte_tagged(to);
        }
}
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);