From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Schwab Subject: Re: [PATCH v2] powerpc: select ARCH_HAS_MEMBARRIER_SYNC_CORE Date: Wed, 15 Jul 2020 12:08:00 +0200 Message-ID: <87zh816qgv.fsf@igel.home> References: <20200715094829.252208-1-npiggin@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-out.m-online.net ([212.18.0.10]:39274 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725811AbgGOKIF (ORCPT ); Wed, 15 Jul 2020 06:08:05 -0400 In-Reply-To: <20200715094829.252208-1-npiggin@gmail.com> (Nicholas Piggin's message of "Wed, 15 Jul 2020 19:48:29 +1000") Sender: linux-arch-owner@vger.kernel.org List-ID: To: Nicholas Piggin Cc: linuxppc-dev@lists.ozlabs.org, Mathieu Desnoyers , linux-arch@vger.kernel.org, Christophe Leroy On Jul 15 2020, Nicholas Piggin wrote: > diff --git a/arch/powerpc/include/asm/exception-64e.h b/arch/powerpc/include/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 synchronising > + * (which rfi is) to support ARCH_HAS_MEMBARRIER_SYNC_CORE without additional > + * additional synchronisation instructions. s/additonal// Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."