efi: dmi: add support for SMBIOS 3.0 UEFI configuration table

This adds support to the UEFI side for detecting the presence of
a SMBIOS 3.0 64-bit entry point. This allows the actual SMBIOS
structure table to reside at a physical offset over 4 GB, which
cannot be supported by the legacy SMBIOS 32-bit entry point.

Since the firmware can legally provide both entry points, store
the SMBIOS 3.0 entry point in a separate variable, and let the
DMI decoding layer decide which one will be used.

Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 0949f9c..0238d61 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -547,6 +547,9 @@
 #define SMBIOS_TABLE_GUID    \
     EFI_GUID(  0xeb9d2d31, 0x2d88, 0x11d3, 0x9a, 0x16, 0x0, 0x90, 0x27, 0x3f, 0xc1, 0x4d )
 
+#define SMBIOS3_TABLE_GUID    \
+    EFI_GUID(  0xf2fd1544, 0x9794, 0x4a2c, 0x99, 0x2e, 0xe5, 0xbb, 0xcf, 0x20, 0xe3, 0x94 )
+
 #define SAL_SYSTEM_TABLE_GUID    \
     EFI_GUID(  0xeb9d2d32, 0x2d88, 0x11d3, 0x9a, 0x16, 0x0, 0x90, 0x27, 0x3f, 0xc1, 0x4d )
 
@@ -810,7 +813,8 @@
 	unsigned long mps;		/* MPS table */
 	unsigned long acpi;		/* ACPI table  (IA64 ext 0.71) */
 	unsigned long acpi20;		/* ACPI table  (ACPI 2.0) */
-	unsigned long smbios;		/* SM BIOS table */
+	unsigned long smbios;		/* SMBIOS table (32 bit entry point) */
+	unsigned long smbios3;		/* SMBIOS table (64 bit entry point) */
 	unsigned long sal_systab;	/* SAL system table */
 	unsigned long boot_info;	/* boot info table */
 	unsigned long hcdp;		/* HCDP table */