efi/libstub/x86: Avoid getter function for efi_is64

We no longer need to take special care when using global variables
in the EFI stub, so switch to a simple symbol reference for efi_is64.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arch/x86/include/asm/efi.h

@@ -225,14 +225,19 @@ efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
 
 /* arch specific definitions used by the stub code */
 
-__attribute_const__ bool efi_is_64bit(void);
+extern const bool efi_is64;
+
+static inline bool efi_is_64bit(void)
+{
+	if (IS_ENABLED(CONFIG_EFI_MIXED))
+		return efi_is64;
+	return IS_ENABLED(CONFIG_X86_64);
+}
 
 static inline bool efi_is_native(void)
 {
 	if (!IS_ENABLED(CONFIG_X86_64))
 		return true;
-	if (!IS_ENABLED(CONFIG_EFI_MIXED))
-		return true;
 	return efi_is_64bit();
 }
 

drivers/firmware/efi/libstub/x86-stub.c

@@ -21,16 +21,8 @@
 #define MAXMEM_X86_64_4LEVEL (1ull << 46)
 
 const efi_system_table_t *efi_system_table;
-extern const bool efi_is64;
 extern u32 image_offset;
 
-__attribute_const__ bool efi_is_64bit(void)
-{
-	if (IS_ENABLED(CONFIG_EFI_MIXED))
-		return efi_is64;
-	return IS_ENABLED(CONFIG_X86_64);
-}
-
 static efi_status_t
 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
 {