efi/x86: Rename efi_is_native() to efi_is_mixed()

The ARM architecture does not permit combining 32-bit and 64-bit code
at the same privilege level, and so EFI mixed mode is strictly a x86
concept.

In preparation of turning the 32/64 bit distinction in shared stub
code to a native vs mixed one, refactor x86's current use of the
helper function efi_is_native() into efi_is_mixed().

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-7-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/efi.h

@@ -153,17 +153,19 @@ extern u64 efi_setup;
 
 #ifdef CONFIG_EFI
 
-static inline bool efi_is_native(void)
+static inline bool efi_is_mixed(void)
 {
-	return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
+	if (!IS_ENABLED(CONFIG_EFI_MIXED))
+		return false;
+	return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
 }
 
 static inline bool efi_runtime_supported(void)
 {
-	if (efi_is_native())
+	if (!efi_is_mixed())
 		return true;
 
-	if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
+	if (!efi_enabled(EFI_OLD_MEMMAP))
 		return true;
 
 	return false;

arch/x86/platform/efi/efi.c

@@ -828,7 +828,7 @@ static bool should_map_region(efi_memory_desc_t *md)
 	 * Map all of RAM so that we can access arguments in the 1:1
 	 * mapping when making EFI runtime calls.
 	 */
-	if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) {
+	if (efi_is_mixed()) {
 		if (md->type == EFI_CONVENTIONAL_MEMORY ||
 		    md->type == EFI_LOADER_DATA ||
 		    md->type == EFI_LOADER_CODE)
@@ -903,7 +903,7 @@ static void __init kexec_enter_virtual_mode(void)
 	 * kexec kernel because in the initial boot something else might
 	 * have been mapped at these virtual addresses.
 	 */
-	if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) {
+	if (efi_is_mixed() || efi_enabled(EFI_OLD_MEMMAP)) {
 		efi_memmap_unmap();
 		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 		return;
@@ -1040,7 +1040,7 @@ static void __init __efi_enter_virtual_mode(void)
 
 	efi_sync_low_kernel_mappings();
 
-	if (efi_is_native()) {
+	if (!efi_is_mixed()) {
 		status = phys_efi_set_virtual_address_map(
 				efi.memmap.desc_size * count,
 				efi.memmap.desc_size,
@@ -1071,7 +1071,7 @@ static void __init __efi_enter_virtual_mode(void)
 	 */
 	efi.runtime_version = efi_systab.hdr.revision;
 
-	if (efi_is_native())
+	if (!efi_is_mixed())
 		efi_native_runtime_setup();
 	else
 		efi_thunk_runtime_setup();

arch/x86/platform/efi/efi_64.c

@@ -388,7 +388,7 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 	 * text and allocate a new stack because we can't rely on the
 	 * stack pointer being < 4GB.
 	 */
-	if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
+	if (!efi_is_mixed())
 		return 0;
 
 	page = alloc_page(GFP_KERNEL|__GFP_DMA32);
@@ -449,7 +449,7 @@ void __init efi_map_region(efi_memory_desc_t *md)
 	 * booting in EFI mixed mode, because even though we may be
 	 * running a 64-bit kernel, the firmware may only be 32-bit.
 	 */
-	if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
+	if (efi_is_mixed()) {
 		md->virt_addr = md->phys_addr;
 		return;
 	}

arch/x86/platform/efi/quirks.c

@@ -395,7 +395,7 @@ static void __init efi_unmap_pages(efi_memory_desc_t *md)
 	 * EFI runtime calls, hence don't unmap EFI boot services code/data
 	 * regions.
 	 */
-	if (!efi_is_native())
+	if (efi_is_mixed())
 		return;
 
 	if (kernel_unmap_pages_in_pgd(pgd, pa, md->num_pages))