x86/boot/efi: Fix __KERNEL_CS definition of GDT entry on 64-bit configurations

Define __KERNEL_CS GDT entry as long mode (.L=1, .D=0) on 64-bit
configurations.

Signed-off-by: Kirill A. Shutemov <[email protected]>
Reviewed-by: Matt Fleming <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: kiryl

arch/x86/boot/compressed/eboot.c

@@ -1059,8 +1059,13 @@ struct boot_params *efi_main(struct efi_config *c,
 	desc->p = 1;
 	desc->limit = 0xf;
 	desc->avl = 0;
-	desc->l = 0;
-	desc->d = SEG_OP_SIZE_32BIT;
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		desc->l = 1;
+		desc->d = 0;
+	} else {
+		desc->l = 0;
+		desc->d = SEG_OP_SIZE_32BIT;
+	}
 	desc->g = SEG_GRANULARITY_4KB;
 	desc->base2 = 0x00;
 	desc++;