arch/x86: Do not access EFI memory map if it is not available

Do not access EFI memory map if it is not available. At least
Xen dom0 EFI implementation does not have an access to it.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index b4059720962389fbf584dbd491332c37e7b58751..7d627a02ed82d8d6cdb0328d1b78bf3379721f70 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -946,6 +946,9 @@ u64 efi_mem_attributes(unsigned long phys_addr)
        efi_memory_desc_t *md;
        void *p;
 
+       if (!efi_enabled(EFI_MEMMAP))
+               return 0;
+
        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
                md = p;
                if ((md->phys_addr <= phys_addr) &&