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

["tip-bot for Kirill A. Shutemov" <tipbot@zytor.com>]

Commit-ID:  4c94117c7fa1bea36a15157022dbe5efee474340
Gitweb:     http://git.kernel.org/tip/4c94117c7fa1bea36a15157022dbe5efee474340
Author:     Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
AuthorDate: Tue, 6 Jun 2017 14:31:23 +0300
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 13 Jun 2017 08:56:52 +0200

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 <kirill.shutemov@linux.intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170606113133.22974-5-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/boot/compressed/eboot.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 1d5093d..b75c20f 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/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++;