ARM: 6120/1: kdump: implement copy_oldmem_page()

This function is used by vmcore code to read a page from the old
kernel memory.

Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Mika Westerberg 2010-05-10 09:26:19 +01:00 committed by Russell King
parent 8594a0c333
commit 67742c8168
2 changed files with 61 additions and 0 deletions

View file

@ -39,6 +39,7 @@ obj-$(CONFIG_ARM_THUMBEE) += thumbee.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_ARM_UNWIND) += unwind.o
obj-$(CONFIG_HAVE_TCM) += tcm.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o
AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312

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@ -0,0 +1,60 @@
/*
* arch/arm/kernel/crash_dump.c
*
* Copyright (C) 2010 Nokia Corporation.
* Author: Mika Westerberg
*
* This code is taken from arch/x86/kernel/crash_dump_64.c
* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
* Copyright (C) IBM Corporation, 2004. All rights reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/errno.h>
#include <linux/crash_dump.h>
#include <linux/uaccess.h>
#include <linux/io.h>
/* stores the physical address of elf header of crash image */
unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
/**
* copy_oldmem_page() - copy one page from old kernel memory
* @pfn: page frame number to be copied
* @buf: buffer where the copied page is placed
* @csize: number of bytes to copy
* @offset: offset in bytes into the page
* @userbuf: if set, @buf is int he user address space
*
* This function copies one page from old kernel memory into buffer pointed by
* @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes
* copied or negative error in case of failure.
*/
ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
size_t csize, unsigned long offset,
int userbuf)
{
void *vaddr;
if (!csize)
return 0;
vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
if (!vaddr)
return -ENOMEM;
if (userbuf) {
if (copy_to_user(buf, vaddr + offset, csize)) {
iounmap(vaddr);
return -EFAULT;
}
} else {
memcpy(buf, vaddr + offset, csize);
}
iounmap(vaddr);
return csize;
}