efi/libstub/arm: Relax FDT alignment requirement

The arm64 kernel no longer requires the FDT blob to fit inside a
naturally aligned 2 MB memory block, so remove the code that aligns
the allocation to 2 MB.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arch/arm64/include/asm/efi.h

@@ -57,13 +57,6 @@ efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
 
 /* arch specific definitions used by the stub code */
 
-/*
- * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
- * start of kernel and may not cross a 2MiB boundary. We set alignment to
- * 2MiB so we know it won't cross a 2MiB boundary.
- */
-#define EFI_FDT_ALIGN	SZ_2M   /* used by allocate_new_fdt_and_exit_boot() */
-
 /*
  * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
  * kernel need greater alignment than we require the segments to be padded to.

drivers/firmware/efi/libstub/fdt.c

@@ -199,10 +199,6 @@ static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map)
 	return EFI_SUCCESS;
 }
 
-#ifndef EFI_FDT_ALIGN
-# define EFI_FDT_ALIGN EFI_PAGE_SIZE
-#endif
-
 struct exit_boot_struct {
 	efi_memory_desc_t	*runtime_map;
 	int			*runtime_entry_count;
@@ -281,7 +277,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
 	pr_efi("Exiting boot services and installing virtual address map...\n");
 
 	map.map = &memory_map;
-	status = efi_high_alloc(MAX_FDT_SIZE, EFI_FDT_ALIGN,
+	status = efi_high_alloc(MAX_FDT_SIZE, EFI_PAGE_SIZE,
 				new_fdt_addr, max_addr);
 	if (status != EFI_SUCCESS) {
 		pr_efi_err("Unable to allocate memory for new device tree.\n");