efi/x86: earlyprintk - Add 64bit efi fb address support

EFI GOP uses 64-bit frame buffer address in some BIOS.
Add 64bit address support in efi earlyprintk.
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

arch/x86/platform/efi/early_printk.c

@@ -26,12 +26,14 @@ static bool early_efi_keep;
  */
 static __init int early_efi_map_fb(void)
 {
-	unsigned long base, size;
+	u64 base, size;
 
 	if (!early_efi_keep)
 		return 0;
 
 	base = boot_params.screen_info.lfb_base;
+	if (boot_params.screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
+		base |= (u64)boot_params.screen_info.ext_lfb_base << 32;
 	size = boot_params.screen_info.lfb_size;
 	efi_fb = ioremap(base, size);
 
@@ -46,9 +48,11 @@ early_initcall(early_efi_map_fb);
  */
 static __ref void *early_efi_map(unsigned long start, unsigned long len)
 {
-	unsigned long base;
+	u64 base;
 
 	base = boot_params.screen_info.lfb_base;
+	if (boot_params.screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
+		base |= (u64)boot_params.screen_info.ext_lfb_base << 32;
 
 	if (efi_fb)
 		return (efi_fb + start);