From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicholas Piggin Subject: Re: [PATCH v2] powerpc: select ARCH_HAS_MEMBARRIER_SYNC_CORE Date: Thu, 16 Jul 2020 10:56:15 +1000 Message-ID: <1594860957.3hoocg9gu6.astroid@bobo.none> References: <20200715094829.252208-1-npiggin@gmail.com> <87zh816qgv.fsf@igel.home> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726479AbgGPA4Z (ORCPT ); Wed, 15 Jul 2020 20:56:25 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFDE4C061755 for ; Wed, 15 Jul 2020 17:56:24 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id j4so5005342wrp.10 for ; Wed, 15 Jul 2020 17:56:24 -0700 (PDT) In-Reply-To: <87zh816qgv.fsf@igel.home> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andreas Schwab Cc: =?iso-8859-1?q?Christophe=0A?= Leroy , linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Mathieu Desnoyers Excerpts from Andreas Schwab's message of July 15, 2020 8:08 pm: > On Jul 15 2020, Nicholas Piggin wrote: >=20 >> diff --git a/arch/powerpc/include/asm/exception-64e.h b/arch/powerpc/inc= lude/asm/exception-64e.h >> index 54a98ef7d7fe..071d7ccb830f 100644 >> --- a/arch/powerpc/include/asm/exception-64e.h >> +++ b/arch/powerpc/include/asm/exception-64e.h >> @@ -204,7 +204,11 @@ exc_##label##_book3e: >> LOAD_REG_ADDR(r3,interrupt_base_book3e);\ >> ori r3,r3,vector_offset@l; \ >> mtspr SPRN_IVOR##vector_number,r3; >> - >> +/* >> + * powerpc relies on return from interrupt/syscall being context synchr= onising >> + * (which rfi is) to support ARCH_HAS_MEMBARRIER_SYNC_CORE without addi= tional >> + * additional synchronisation instructions. >=20 > s/additonal// Will fix in a respin. Thanks, Nick