mirror of https://gitee.com/openkylin/linux.git
73 lines
2.1 KiB
C
73 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* 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/uaccess.h>
|
|
#include <linux/io.h>
|
|
|
|
static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
|
|
unsigned long offset, int userbuf,
|
|
bool encrypted)
|
|
{
|
|
void *vaddr;
|
|
|
|
if (!csize)
|
|
return 0;
|
|
|
|
if (encrypted)
|
|
vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE);
|
|
else
|
|
vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
|
|
|
|
if (!vaddr)
|
|
return -ENOMEM;
|
|
|
|
if (userbuf) {
|
|
if (copy_to_user((void __user *)buf, vaddr + offset, csize)) {
|
|
iounmap((void __iomem *)vaddr);
|
|
return -EFAULT;
|
|
}
|
|
} else
|
|
memcpy(buf, vaddr + offset, csize);
|
|
|
|
set_iounmap_nonlazy();
|
|
iounmap((void __iomem *)vaddr);
|
|
return csize;
|
|
}
|
|
|
|
/**
|
|
* copy_oldmem_page - copy one page of memory
|
|
* @pfn: page frame number to be copied
|
|
* @buf: target memory address for the copy; this can be in kernel address
|
|
* space or user address space (see @userbuf)
|
|
* @csize: number of bytes to copy
|
|
* @offset: offset in bytes into the page (based on pfn) to begin the copy
|
|
* @userbuf: if set, @buf is in user address space, use copy_to_user(),
|
|
* otherwise @buf is in kernel address space, use memcpy().
|
|
*
|
|
* Copy a page from the old kernel's memory. For this page, there is no pte
|
|
* mapped in the current kernel. We stitch up a pte, similar to kmap_atomic.
|
|
*/
|
|
ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
|
|
unsigned long offset, int userbuf)
|
|
{
|
|
return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false);
|
|
}
|
|
|
|
/**
|
|
* copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the
|
|
* memory with the encryption mask set to accommodate kdump on SME-enabled
|
|
* machines.
|
|
*/
|
|
ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
|
|
unsigned long offset, int userbuf)
|
|
{
|
|
return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true);
|
|
}
|