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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 7402AC433C1 for ; Sun, 28 Mar 2021 11:47:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4047D6196C for ; Sun, 28 Mar 2021 11:47:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231310AbhC1Lhd (ORCPT ); Sun, 28 Mar 2021 07:37:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:41110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231260AbhC1LhF (ORCPT ); Sun, 28 Mar 2021 07:37:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9E3B96197C; Sun, 28 Mar 2021 11:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616931420; bh=8r+E9jML76H0gCn8zByIpf9ts7froA6i3yzLNHuBvN4=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=DugdbpT4GDM1HZeaem5soSAi/FHElDFHhmz2xIpsZJUkasWv28ZB3zgK93tR/c1EG Wg6UZIL/32OGSKHjIL7I3TejYIFIJatZ2S0hfZTZhMaw3y2P3h3z4TJdRouH33c2P4 a0vFE4t1YxIuiIc5HdVc8iBz2z/pz1daXtvTbooBxBTN2T1IZ64j2pxee2ABx/u+UN R9Tpd5W1OnKdE7r9gQzXgqssvnkZagFrOM0DWS5GTeRlV6XS25xWzL3c0iO1XPbWAb sCLOKxIHwnhTcR+YQphOeEdtMjQrjqZYOIz3pgbUdAYY8+PAy495HKeu1P90Dt67iE cgL/CGET6Tr6g== Received: by mail-lf1-f44.google.com with SMTP id q29so14175994lfb.4; Sun, 28 Mar 2021 04:37:00 -0700 (PDT) X-Gm-Message-State: AOAM5330m1XrE5OgTu5q3ngejJWzGUDNGl8342twXJp9PSj4WYCmr3oD FYrhOux5BGjkQyDNKef7fm0FBwvqH+4PVjgndZw= X-Google-Smtp-Source: ABdhPJyj9o7D6hGhD+tmVxlzoBXg46BNhDKM+Nvrw+oWgxcsNgQKl214mB8IGaefEjDYpDQx2VSVsVg9V+sA7ebVJIA= X-Received: by 2002:a19:f501:: with SMTP id j1mr14083138lfb.231.1616931418962; Sun, 28 Mar 2021 04:36:58 -0700 (PDT) MIME-Version: 1.0 References: <1616913028-83376-1-git-send-email-guoren@kernel.org> <1616913028-83376-5-git-send-email-guoren@kernel.org> In-Reply-To: From: Guo Ren Date: Sun, 28 Mar 2021 19:36:47 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v5 4/7] powerpc/qspinlock: Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32 To: Christophe Leroy Cc: linux-arch , linux-xtensa@linux-xtensa.org, Guo Ren , Linux Kernel Mailing List , linux-csky@vger.kernel.org, openrisc@lists.librecores.org, Paul Mackerras , sparclinux , linux-riscv , linuxppc-dev@lists.ozlabs.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org On Sun, Mar 28, 2021 at 7:14 PM Christophe Leroy wrote: > > > > Le 28/03/2021 =C3=A0 08:30, guoren@kernel.org a =C3=A9crit : > > From: Guo Ren > > > > We don't have native hw xchg16 instruction, so let qspinlock > > generic code to deal with it. > > We have lharx/sthcx pair on some versions of powerpc. > > See https://patchwork.ozlabs.org/project/linuxppc-dev/patch/2020110703232= 8.2454582-1-npiggin@gmail.com/ Got it, thx for the information. > > Christophe > > > > > Using the full-word atomic xchg instructions implement xchg16 has > > the semantic risk for atomic operations. > > > > This patch cancels the dependency of on qspinlock generic code on > > architecture's xchg16. > > > > Signed-off-by: Guo Ren > > Cc: Michael Ellerman > > Cc: Benjamin Herrenschmidt > > Cc: Paul Mackerras > > --- > > arch/powerpc/Kconfig | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > > index 386ae12d8523..69ec4ade6521 100644 > > --- a/arch/powerpc/Kconfig > > +++ b/arch/powerpc/Kconfig > > @@ -151,6 +151,7 @@ config PPC > > select ARCH_USE_CMPXCHG_LOCKREF if PPC64 > > select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS > > select ARCH_USE_QUEUED_SPINLOCKS if PPC_QUEUED_SPINLOCKS > > + select ARCH_USE_QUEUED_SPINLOCKS_XCHG32 if PPC_QUEUED_SPINLOCKS > > select ARCH_WANT_IPC_PARSE_VERSION > > select ARCH_WANT_IRQS_OFF_ACTIVATE_MM > > select ARCH_WANT_LD_ORPHAN_WARN > > --=20 Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/