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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 A8C29C48BE6 for ; Wed, 16 Jun 2021 23:49:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A8FF611EE for ; Wed, 16 Jun 2021 23:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234797AbhFPXv0 (ORCPT ); Wed, 16 Jun 2021 19:51:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:54282 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232372AbhFPXv0 (ORCPT ); Wed, 16 Jun 2021 19:51:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0FCFF613AE; Wed, 16 Jun 2021 23:49:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623887359; bh=qIUOjJaXnnZDIyqjA+8Rc1PjQR2ZFeNFFdkcFco2deg=; h=In-Reply-To:References:Date:From:To:Cc:Subject:From; b=tLLlTT5QYvEBvhHyFgtlIUon6gCPPxmjtFckUGTgYydeAEqnZDsIDRjwwA4edaT4i SxjOwyOiiypMhRc5geGG5OgstPcC5Zydag4FyTShAXeUicNHyag/uwd+Bf8addiz00 r8/1njn1ijQGDlnV6k+rfHTFwz46KsHf/SjGCMx9fE58OFAK//3XD6VMtAMLWQzk6n Ev9xVT4vvdAIgmQ8AxLgsQmZwVDU9W6/It1AubbzeAKkkNmTvi/EmCaGXdyXb5HH2s XJk7RGwQv/SyH4TP+iKmDKoEdgMvZtMBHTC+hzuUNyU6fbMwMEk2cicq8FRa861MWQ vOcPKj4sc0mRw== Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailauth.nyi.internal (Postfix) with ESMTP id 1C2F927C0054; Wed, 16 Jun 2021 19:49:17 -0400 (EDT) Received: from imap21 ([10.202.2.71]) by compute2.internal (MEProxy); Wed, 16 Jun 2021 19:49:17 -0400 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrfeeftddgvddvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepofgfggfkjghffffhvffutgesthdtredtreerjeenucfhrhhomhepfdetnhgu hicunfhuthhomhhirhhskhhifdcuoehluhhtoheskhgvrhhnvghlrdhorhhgqeenucggtf frrghtthgvrhhnpeegjefghfdtledvfeegfeelvedtgfevkeeugfekffdvveeffeetieeh ueetveekfeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhroh hmpegrnhguhidomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqudduiedukeeh ieefvddqvdeifeduieeitdekqdhluhhtoheppehkvghrnhgvlhdrohhrgheslhhinhhugi drlhhuthhordhush X-ME-Proxy: Received: by mailuser.nyi.internal (Postfix, from userid 501) id 8540951C0060; Wed, 16 Jun 2021 19:49:15 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.5.0-alpha0-526-gf020ecf851-fm-20210616.001-gf020ecf8 Mime-Version: 1.0 Message-Id: <57dae79c-fff8-411f-a375-1aa8a1cd10ac@www.fastmail.com> In-Reply-To: <1e248763-9372-6e4e-5dea-cda999000aeb@kernel.org> References: <07a8b963002cb955b7516e61bad19514a3acaa82.1623813516.git.luto@kernel.org> <1623818343.eko1v01gvr.astroid@bobo.none> <1e248763-9372-6e4e-5dea-cda999000aeb@kernel.org> Date: Wed, 16 Jun 2021 16:48:54 -0700 From: "Andy Lutomirski" To: "Nicholas Piggin" , "the arch/x86 maintainers" Cc: "Andrew Morton" , "Benjamin Herrenschmidt" , "Catalin Marinas" , "Dave Hansen" , linux-arm-kernel@lists.infradead.org, "Linux Kernel Mailing List" , linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, "Mathieu Desnoyers" , "Michael Ellerman" , "Paul Mackerras" , "Peter Zijlstra (Intel)" , stable@vger.kernel.org, "Will Deacon" Subject: =?UTF-8?Q?Re:_[PATCH_8/8]_membarrier:_Rewrite_sync=5Fcore=5Fbefore=5Fuse?= =?UTF-8?Q?rmode()_and_improve_documentation?= Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 16, 2021, at 11:52 AM, Andy Lutomirski wrote: > On 6/15/21 9:45 PM, Nicholas Piggin wrote: > > Excerpts from Andy Lutomirski's message of June 16, 2021 1:21 pm: > >> The old sync_core_before_usermode() comments suggested that a non-icache-syncing > >> return-to-usermode instruction is x86-specific and that all other > >> architectures automatically notice cross-modified code on return to > >> userspace. > > >> +/* > >> + * XXX: can a powerpc person put an appropriate comment here? > >> + */ > >> +static inline void membarrier_sync_core_before_usermode(void) > >> +{ > >> +} > >> + > >> +#endif /* _ASM_POWERPC_SYNC_CORE_H */ > > > > powerpc's can just go in asm/membarrier.h > > $ ls arch/powerpc/include/asm/membarrier.h > ls: cannot access 'arch/powerpc/include/asm/membarrier.h': No such file > or directory Which is because I deleted it. Duh. I'll clean this up. > > > > > > /* > > * The RFI family of instructions are context synchronising, and > > * that is how we return to userspace, so nothing is required here. > > */ > > Thanks! >