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-rw-r--r--arch/i386/mm/highmem.c18
-rw-r--r--include/asm-i386/highmem.h1
-rw-r--r--include/linux/crash_dump.h13
-rw-r--r--include/linux/highmem.h1
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/crash_dump.c49
6 files changed, 83 insertions, 0 deletions
diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c
index 4b7aaf99d7ea..b6eb4dcb8777 100644
--- a/arch/i386/mm/highmem.c
+++ b/arch/i386/mm/highmem.c
@@ -75,6 +75,24 @@ void kunmap_atomic(void *kvaddr, enum km_type type)
preempt_check_resched();
}
+/* This is the same as kmap_atomic() but can map memory that doesn't
+ * have a struct page associated with it.
+ */
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+{
+ enum fixed_addresses idx;
+ unsigned long vaddr;
+
+ inc_preempt_count();
+
+ idx = type + KM_TYPE_NR*smp_processor_id();
+ vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+ set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot));
+ __flush_tlb_one(vaddr);
+
+ return (void*) vaddr;
+}
+
struct page *kmap_atomic_to_page(void *ptr)
{
unsigned long idx, vaddr = (unsigned long)ptr;
diff --git a/include/asm-i386/highmem.h b/include/asm-i386/highmem.h
index 1df42bf347df..0fd331306b60 100644
--- a/include/asm-i386/highmem.h
+++ b/include/asm-i386/highmem.h
@@ -70,6 +70,7 @@ void *kmap(struct page *page);
void kunmap(struct page *page);
void *kmap_atomic(struct page *page, enum km_type type);
void kunmap_atomic(void *kvaddr, enum km_type type);
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
struct page *kmap_atomic_to_page(void *ptr);
#define flush_cache_kmaps() do { } while (0)
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
new file mode 100644
index 000000000000..7d983b817429
--- /dev/null
+++ b/include/linux/crash_dump.h
@@ -0,0 +1,13 @@
+#ifndef LINUX_CRASH_DUMP_H
+#define LINUX_CRASH_DUMP_H
+
+#ifdef CONFIG_CRASH_DUMP
+#include <linux/kexec.h>
+#include <linux/smp_lock.h>
+#include <linux/device.h>
+#include <linux/proc_fs.h>
+
+extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
+ unsigned long, int);
+#endif /* CONFIG_CRASH_DUMP */
+#endif /* LINUX_CRASHDUMP_H */
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 2a7e6c65c882..6bece9280eb7 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -28,6 +28,7 @@ static inline void *kmap(struct page *page)
#define kmap_atomic(page, idx) page_address(page)
#define kunmap_atomic(addr, idx) do { } while (0)
+#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
#endif /* CONFIG_HIGHMEM */
diff --git a/kernel/Makefile b/kernel/Makefile
index cfc8b0dea950..cb05cd05d237 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_SYSFS) += ksysfs.o
obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
+obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_SECCOMP) += seccomp.o
ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
diff --git a/kernel/crash_dump.c b/kernel/crash_dump.c
new file mode 100644
index 000000000000..5a1e6d5d203e
--- /dev/null
+++ b/kernel/crash_dump.c
@@ -0,0 +1,49 @@
+/*
+ * 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>
+
+/*
+ * 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;
+}

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