[PATCH] kdump: read previous kernel's memory

- Moving the crash_dump.c file to arch dependent part as kmap_atomic_pfn is
  specific to i386 and highmem may not exist in other archs.

- Use ioremap for x86_64 to map the previous kernel memory.

- In copy_oldmem_page(), we now directly copy to the user/kernel buffer and
  avoid the unneccesary copy to a kmalloc'd page.

Signed-off-by: Rachita Kothiyal <rachita@in.ibm.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 0 insertions, 65 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index a940bac0283..1e039700c0a 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -30,7 +30,6 @@ obj-$(CONFIG_KPROBES) += kprobes.o
 obj-$(CONFIG_SYSFS) += ksysfs.o
 obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
 obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
-obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
 obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 
diff --git a/kernel/crash_dump.c b/kernel/crash_dump.c
deleted file mode 100644
index fccb27dbc62..00000000000
--- a/kernel/crash_dump.c
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- *	kernel/crash_dump.c - Memory preserving reboot related code.
- *
- *	Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
- *	Copyright (C) IBM Corporation, 2004. All rights reserved
- */
-
-#include <linux/smp_lock.h>
-#include <linux/errno.h>
-#include <linux/proc_fs.h>
-#include <linux/bootmem.h>
-#include <linux/highmem.h>
-#include <linux/crash_dump.h>
-
-#include <asm/io.h>
-#include <asm/uaccess.h>
-#include <asm/kexec.h>
-
-/* Stores the physical address of elf header of crash image. */
-unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
-
-#ifndef HAVE_ARCH_COPY_OLDMEM_PAGE
-/**
- * copy_oldmem_page - copy one page from "oldmem"
- * @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 "oldmem". 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)
-{
-	void *page, *vaddr;
-
-	if (!csize)
-		return 0;
-
-	page = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!page)
-		return -ENOMEM;
-
-	vaddr = kmap_atomic_pfn(pfn, KM_PTE0);
-	copy_page(page, vaddr);
-	kunmap_atomic(vaddr, KM_PTE0);
-
-	if (userbuf) {
-		if (copy_to_user(buf, (page + offset), csize)) {
-			kfree(page);
-			return -EFAULT;
-		}
-	} else {
-		memcpy(buf, (page + offset), csize);
-	}
-
-	kfree(page);
-	return csize;
-}
-#endif