// SPDX-License-Identifier: GPL-2.0/* *	crash_dump.c - Memory preserving reboot related code. * *	Created by: Hariprasad Nellitheertha (hari@in.ibm.com) *	Copyright (C) IBM Corporation, 2004. All rights reserved */#include <linux/errno.h>#include <linux/crash_dump.h>#include <linux/io.h>#include <linux/uio.h>#include <linux/uaccess.h> ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,			 size_t csize, unsigned long offset){	void  __iomem *vaddr; 	if (!csize)		return 0; 	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);	csize = copy_to_iter(vaddr + offset, csize, iter);	iounmap(vaddr); 	return csize;}