[S390] kernel: Add OS info memory interface

In order to allow kdump based stand-alone dump, some information
has to be passed from the old kernel to the new dump kernel. This
is done via a the struct "os_info" that contains the following fields:
 * crashkernel base and size
 * reipl block
 * vmcoreinfo
 * init function
A pointer to os_info is stored at a well known storage location
and the whole structure as well as all fields are secured with
checksums.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/arch/s390/include/asm/os_info.h b/arch/s390/include/asm/os_info.h
new file mode 100644
index 000000000000..d07518af09ea
--- /dev/null
+++ b/arch/s390/include/asm/os_info.h
@@ -0,0 +1,50 @@
+/*
+ * OS info memory interface
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+#ifndef _ASM_S390_OS_INFO_H
+#define _ASM_S390_OS_INFO_H
+
+#define OS_INFO_VERSION_MAJOR   1
+#define OS_INFO_VERSION_MINOR   1
+#define OS_INFO_MAGIC           0x4f53494e464f535aULL /* OSINFOSZ */
+
+#define OS_INFO_VMCOREINFO      0
+#define OS_INFO_REIPL_BLOCK     1
+#define OS_INFO_INIT_FN         2
+
+struct os_info_entry {
+        u64     addr;
+        u64     size;
+        u32     csum;
+} __packed;
+
+struct os_info {
+        u64     magic;
+        u32     csum;
+        u16     version_major;
+        u16     version_minor;
+        u64     crashkernel_addr;
+        u64     crashkernel_size;
+        struct os_info_entry entry[3];
+        u8      reserved[4004];
+} __packed;
+
+void os_info_init(void);
+void os_info_entry_add(int nr, void *ptr, u64 len);
+void os_info_crashkernel_add(unsigned long base, unsigned long size);
+u32 os_info_csum(struct os_info *os_info);
+
+#ifdef CONFIG_CRASH_DUMP
+void *os_info_old_entry(int nr, unsigned long *size);
+int copy_from_oldmem(void *dest, void *src, size_t count);
+#else
+static inline void *os_info_old_entry(int nr, unsigned long *size)
+{
+        return NULL;
+}
+#endif
+
+#endif /* _ASM_S390_OS_INFO_H */