Merge /spare/repo/linux-2.6/

1 files changed, 61 insertions, 0 deletions

diff --git a/kernel/crash_dump.c b/kernel/crash_dump.c
new file mode 100644
index 000000000000..334c37f5218a
--- /dev/null
+++ b/kernel/crash_dump.c
@@ -0,0 +1,61 @@
+/*
+ *      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>
+
+/* 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 "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;
+}