Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751406AbdHaJ6R (ORCPT ); Thu, 31 Aug 2017 05:58:17 -0400 Received: from conuserg-07.nifty.com ([210.131.2.74]:30791 "EHLO conuserg-07.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751332AbdHaJ6P (ORCPT ); Thu, 31 Aug 2017 05:58:15 -0400 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-07.nifty.com v7V9uaqW001078 X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-arm-kernel@lists.infradead.org, Will Deacon , Catalin Marinas Cc: Olof Johansson , Arnd Bergmann , Rob Herring , Russell King , Marc Zyngier , Masahiro Yamada , linux-kernel@vger.kernel.org Subject: [PATCH] arm64: relax assembly code alignment from 16 byte to 4 byte Date: Thu, 31 Aug 2017 18:56:23 +0900 Message-Id: <1504173383-8367-1-git-send-email-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1187 Lines: 42 Aarch64 instructions must be word aligned. The current 16 byte alignment is more than enough. Relax it into 4 byte alignment. Signed-off-by: Masahiro Yamada --- I do not know why arm64 Linux requires 16 byte alignment. I dug git-history of arch/arm64/include/asm/linkage.h and the only commit I see is: commit aeed41a9371ee02257b608eb06a9058507a7d0f4 Author: Marc Zyngier Date: Fri Oct 19 17:33:27 2012 +0100 arm64: fix alignment padding in assembly code It just opt out of the asm-generic variant to remove 0x90. So, the amount of alignment might not be not optimized yet. Please correct me if I am missing something. arch/arm64/include/asm/linkage.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/linkage.h b/arch/arm64/include/asm/linkage.h index 636c1bc..1b26629 100644 --- a/arch/arm64/include/asm/linkage.h +++ b/arch/arm64/include/asm/linkage.h @@ -1,7 +1,7 @@ #ifndef __ASM_LINKAGE_H #define __ASM_LINKAGE_H -#define __ALIGN .align 4 -#define __ALIGN_STR ".align 4" +#define __ALIGN .align 2 +#define __ALIGN_STR ".align 2" #endif -- 2.7.4