efi: Add support for using efivars as a pstore backend

EFI provides an area of nonvolatile storage managed by the firmware. We
can use this as a pstore backend to maintain copies of oopses, aiding
diagnosis.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/include/linux/efi.h b/include/linux/efi.h
index e376270..c1f5107 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -19,6 +19,7 @@
 #include <linux/rtc.h>
 #include <linux/ioport.h>
 #include <linux/pfn.h>
+#include <linux/pstore.h>
 
 #include <asm/page.h>
 #include <asm/system.h>
@@ -211,6 +212,9 @@
 #define UV_SYSTEM_TABLE_GUID \
     EFI_GUID(  0x3b13a7d4, 0x633e, 0x11dd, 0x93, 0xec, 0xda, 0x25, 0x56, 0xd8, 0x95, 0x93 )
 
+#define LINUX_EFI_CRASH_GUID \
+    EFI_GUID(  0xcfc8fc79, 0xbe2e, 0x4ddc, 0x97, 0xf0, 0x9f, 0x98, 0xbf, 0xe2, 0x98, 0xa0 )
+
 typedef struct {
 	efi_guid_t guid;
 	unsigned long table;
@@ -426,6 +430,8 @@
 	struct kset *kset;
 	struct bin_attribute *new_var, *del_var;
 	const struct efivar_operations *ops;
+	struct efivar_entry *walk_entry;
+	struct pstore_info efi_pstore_info;
 };
 
 int register_efivars(struct efivars *efivars,