From 67742c8168ed66fdd6cb5dc90e06c43cdc5bba07 Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@iki.fi>
Date: Mon, 10 May 2010 09:26:19 +0100
Subject: 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>
---
arch/arm/kernel/crash_dump.c | 60 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
create mode 100644 arch/arm/kernel/crash_dump.c
(limited to 'arch/arm/kernel/crash_dump.c')
diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c
new file mode 100644
index 00000000000..cd3b853a8a6
--- /dev/null
+++ b/arch/arm/kernel/crash_dump.c
@@ -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;
+}
--
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