static bool should_map_region(efi_memory_desc_t *md)
{
	/*
	 * Runtime regions always require runtime mappings (obviously).
	 */
	if (md->attribute & EFI_MEMORY_RUNTIME)
		return true;

	/*
	 * 32-bit EFI doesn't suffer from the bug that requires us to
	 * reserve boot services regions, and mixed mode support
	 * doesn't exist for 32-bit kernels.
	 */
	if (IS_ENABLED(CONFIG_X86_32))
		return false;

	/*
	 * 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 (md->type == EFI_CONVENTIONAL_MEMORY ||
		    md->type == EFI_LOADER_DATA ||
		    md->type == EFI_LOADER_CODE)
			return true;
	}

	/*
	 * Map boot services regions as a workaround for buggy
	 * firmware that accesses them even when they shouldn't.
	 *
	 * See efi_{reserve,free}_boot_services().
	 */
	if (md->type == EFI_BOOT_SERVICES_CODE ||
	    md->type == EFI_BOOT_SERVICES_DATA)
		return true;

	return false;
}
Unknown