From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BC2FC282DD for ; Thu, 9 Jan 2020 16:51:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67B1520721 for ; Thu, 9 Jan 2020 16:51:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387900AbgAIQvu (ORCPT ); Thu, 9 Jan 2020 11:51:50 -0500 Received: from foss.arm.com ([217.140.110.172]:34604 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731549AbgAIQvu (ORCPT ); Thu, 9 Jan 2020 11:51:50 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 988491FB; Thu, 9 Jan 2020 08:51:49 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 519C73F703; Thu, 9 Jan 2020 08:51:48 -0800 (PST) Date: Thu, 9 Jan 2020 16:51:46 +0000 From: Mark Rutland To: Julien Thierry Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, jpoimboe@redhat.com, peterz@infradead.org, raphael.gault@arm.com, catalin.marinas@arm.com, will@kernel.org Subject: Re: [RFC v5 56/57] arm64: entry: Avoid empty alternatives entries Message-ID: <20200109165145.GI3112@lakrids.cambridge.arm.com> References: <20200109160300.26150-1-jthierry@redhat.com> <20200109160300.26150-57-jthierry@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200109160300.26150-57-jthierry@redhat.com> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 09, 2020 at 04:02:59PM +0000, Julien Thierry wrote: > kernel_ventry will create alternative entries to potentially replace > 0 instructions with 0 instructions for EL1 vectors. While this does not > cause an issue, it pointlessly takes up some bytes in the alternatives > section. > > Do not generate such entries. > > Signed-off-by: Julien Thierry This looks like a sensible cleanup on its own. FWIW: Acked-by: Mark Rutland Mark. > --- > arch/arm64/kernel/entry.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 7c6a0a41676f..605bb7cbe499 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -60,16 +60,16 @@ > .macro kernel_ventry, el, label, regsize = 64 > .align 7 > #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 > -alternative_if ARM64_UNMAP_KERNEL_AT_EL0 > .if \el == 0 > +alternative_if ARM64_UNMAP_KERNEL_AT_EL0 > .if \regsize == 64 > mrs x30, tpidrro_el0 > msr tpidrro_el0, xzr > .else > mov x30, xzr > .endif > - .endif > alternative_else_nop_endif > + .endif > #endif > > sub sp, sp, #S_FRAME_SIZE > -- > 2.21.0 >