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
14static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
15				  unsigned long offset, int userbuf,
16				  bool encrypted)
 
 
 
 
 
 
 
 
 
 
 
 
17{
18	void  *vaddr;
19
20	if (!csize)
21		return 0;
22
23	if (encrypted)
24		vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE);
25	else
26		vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
27
28	if (!vaddr)
29		return -ENOMEM;
30
31	if (userbuf) {
32		if (copy_to_user((void __user *)buf, vaddr + offset, csize)) {
33			iounmap((void __iomem *)vaddr);
34			return -EFAULT;
35		}
36	} else
37		memcpy(buf, vaddr + offset, csize);
38
39	set_iounmap_nonlazy();
40	iounmap((void __iomem *)vaddr);
41	return csize;
42}
43
44/**
45 * copy_oldmem_page - copy one page of memory
46 * @pfn: page frame number to be copied
47 * @buf: target memory address for the copy; this can be in kernel address
48 *	space or user address space (see @userbuf)
49 * @csize: number of bytes to copy
50 * @offset: offset in bytes into the page (based on pfn) to begin the copy
51 * @userbuf: if set, @buf is in user address space, use copy_to_user(),
52 *	otherwise @buf is in kernel address space, use memcpy().
53 *
54 * Copy a page from the old kernel's memory. For this page, there is no pte
55 * mapped in the current kernel. We stitch up a pte, similar to kmap_atomic.
56 */
57ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
58			 unsigned long offset, int userbuf)
59{
60	return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false);
61}
62
63/**
64 * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the
65 * memory with the encryption mask set to accommodate kdump on SME-enabled
66 * machines.
67 */
68ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
69				   unsigned long offset, int userbuf)
70{
71	return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true);
72}
73
74ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
75{
76	return read_from_oldmem(buf, count, ppos, 0, sev_active());
77}

 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}