1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * arch/arm/kernel/crash_dump.c
4  *
5  * Copyright (C) 2010 Nokia Corporation.
6  * Author: Mika Westerberg
7  *
8  * This code is taken from arch/x86/kernel/crash_dump_64.c
9  *   Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
10  *   Copyright (C) IBM Corporation, 2004. All rights reserved
11  */
12 
13 #include <linux/errno.h>
14 #include <linux/crash_dump.h>
15 #include <linux/uaccess.h>
16 #include <linux/io.h>
17 #include <linux/uio.h>
18 
copy_oldmem_page(struct iov_iter * iter,unsigned long pfn,size_t csize,unsigned long offset)19 ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
20 			 size_t csize, unsigned long offset)
21 {
22 	void *vaddr;
23 
24 	if (!csize)
25 		return 0;
26 
27 	vaddr = ioremap(__pfn_to_phys(pfn), PAGE_SIZE);
28 	if (!vaddr)
29 		return -ENOMEM;
30 
31 	csize = copy_to_iter(vaddr + offset, csize, iter);
32 
33 	iounmap(vaddr);
34 	return csize;
35 }
36