// SPDX-License-Identifier: GPL-2.0
#include <linux/highmem.h>
#include <linux/crash_dump.h>
#include <linux/uio.h>

ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
                         size_t csize, unsigned long offset)
{
        void  *vaddr;

        if (!csize)
                return 0;

        vaddr = kmap_local_pfn(pfn);
        csize = copy_to_iter(vaddr + offset, csize, iter);
        kunmap_local(vaddr);

        return csize;
}