1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 *	Memory preserving reboot related code.
 4 *
 5 *	Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
 6 *	Copyright (C) IBM Corporation, 2004. All rights reserved
 7 */
 8
 9#include <linux/errno.h>
10#include <linux/crash_dump.h>
11#include <linux/uaccess.h>
12#include <linux/io.h>
 
13
14/**
15 * copy_oldmem_page - copy one page from "oldmem"
16 * @pfn: page frame number to be copied
17 * @buf: target memory address for the copy; this can be in kernel address
18 *	space or user address space (see @userbuf)
19 * @csize: number of bytes to copy
20 * @offset: offset in bytes into the page (based on pfn) to begin the copy
21 * @userbuf: if set, @buf is in user address space, use copy_to_user(),
22 *	otherwise @buf is in kernel address space, use memcpy().
23 *
24 * Copy a page from "oldmem". For this page, there is no pte mapped
25 * in the current kernel. We stitch up a pte, similar to kmap_atomic.
26 */
27ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
28		size_t csize, unsigned long offset, int userbuf)
29{
30	void  *vaddr;
31
32	if (!csize)
33		return 0;
34
35	vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
 
 
 
 
36	if (!vaddr)
37		return -ENOMEM;
38
39	if (userbuf) {
40		if (copy_to_user(buf, vaddr + offset, csize)) {
41			iounmap(vaddr);
42			return -EFAULT;
43		}
44	} else
45		memcpy(buf, vaddr + offset, csize);
46
47	set_iounmap_nonlazy();
48	iounmap(vaddr);
49	return csize;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
50}

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 *	Memory preserving reboot related code.
 4 *
 5 *	Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
 6 *	Copyright (C) IBM Corporation, 2004. All rights reserved
 7 */
 8
 9#include <linux/errno.h>
10#include <linux/crash_dump.h>
11#include <linux/uio.h>
12#include <linux/io.h>
13#include <linux/cc_platform.h>
14
15static ssize_t __copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
16				  size_t csize, unsigned long offset,
17				  bool encrypted)
 
 
 
 
 
 
 
 
 
 
 
 
18{
19	void  *vaddr;
20
21	if (!csize)
22		return 0;
23
24	if (encrypted)
25		vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE);
26	else
27		vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
28
29	if (!vaddr)
30		return -ENOMEM;
31
32	csize = copy_to_iter(vaddr + offset, csize, iter);
 
 
 
 
 
 
33
34	iounmap((void __iomem *)vaddr);
 
35	return csize;
36}
37
38ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
39			 unsigned long offset)
40{
41	return __copy_oldmem_page(iter, pfn, csize, offset, false);
42}
43
44/*
45 * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the
46 * memory with the encryption mask set to accommodate kdump on SME-enabled
47 * machines.
48 */
49ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn,
50				   size_t csize, unsigned long offset)
51{
52	return __copy_oldmem_page(iter, pfn, csize, offset, true);
53}
54
55ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
56{
57	struct kvec kvec = { .iov_base = buf, .iov_len = count };
58	struct iov_iter iter;
59
60	iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
61
62	return read_from_oldmem(&iter, count, ppos,
63				cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT));
64}