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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 56288C46CD2 for ; Wed, 24 Jan 2024 16:18:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=iGfN/Vgk0KOolFL/R0R5BhModt7QNcx5fZHBL7rO9mk=; b=bbR0rNvsFzRpEW M7/8QHFzJuo0rAAnMj9Ivk3/O7T4BM3CPmqYGL/0f95t8tjD4tl5b9lfd3RKeSUh4wgWNIPgJNZWd EL4A/ZUcoiOVBqGKCF4K5KQrucL0UyBeEXbyDiMDX8zH+bNVP7uC9baS7B0t/wV/NRIbRgfssnCyJ PdUQmlMm8yu4CumGNZzYtu8YiEdKXAC560Kxdo6JeAKJwiYlHOxGT4mcVLgHEExqzxLfVCFo7Y48u b31FktFTEr32MTXFeBv8UNXhwQ7035XQ6yFTH8fdRGZYXjq9sF+9cf0HOhUZayTLki59+JvBfl9lB 660Xk/3vbBjRgElDUDzw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rSfxU-0049u1-2H; Wed, 24 Jan 2024 16:18:36 +0000 Received: from smtpout.efficios.com ([2607:5300:203:b2ee::31e5]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rSfxP-0049qu-2W for linux-riscv@lists.infradead.org; Wed, 24 Jan 2024 16:18:34 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1706113110; bh=fdb4Zk8kpS57cz7UQOaWOD8Gc/oHuCpHnm87tMS4JXQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rK3w1FWZECH8ewCqknoAwEohXevMn+PQBx7pEAb01wOihiY3/DfpbEPyknog+SkAg QLMn7tFVyTz8pw96EfO5j6yk6p4o0U6uDWs1mCVPZiBlvJGrvLV7tMrLx9nCBlmzwQ scxJB91Do6jit+Nm4xDCcHMunRlwKYUIqmO5par4mrEKfjAQY2ziQ06cxSxJ4EZDXp kGCODRxkCuQ6Rng7lBEfiZ8mxCP5E52W/GqsXedcKvqMgk7FkmTUeo12L6g9fCrwss K+lPAEyZDvxMLUk/AWq4mPOnVmVFOBEExUSHaSfCyzjhfyIIvl3DEhWpdGjHkpYS2t R72AnGsc8e+Mw== Received: from [172.16.0.134] (192-222-143-198.qc.cable.ebox.net [192.222.143.198]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4TKpzV2MbBzV72; Wed, 24 Jan 2024 11:18:30 -0500 (EST) Message-ID: Date: Wed, 24 Jan 2024 11:18:30 -0500 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 4/4] membarrier: riscv: Provide core serializing command Content-Language: en-US To: Andrea Parri , paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, paulmck@kernel.org, corbet@lwn.net Cc: mmaas@google.com, hboehm@google.com, striker@us.ibm.com, charlie@rivosinc.com, rehn@rivosinc.com, linux-riscv@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20240110145533.60234-1-parri.andrea@gmail.com> <20240110145533.60234-5-parri.andrea@gmail.com> From: Mathieu Desnoyers In-Reply-To: <20240110145533.60234-5-parri.andrea@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240124_081831_890353_DD1CACEB X-CRM114-Status: UNSURE ( 9.43 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On 2024-01-10 09:55, Andrea Parri wrote: [...] > > diff --git a/Documentation/features/sched/membarrier-sync-core/arch-support.txt b/Documentation/features/sched/membarrier-sync-core/arch-support.txt > index d96b778b87ed8..a163170fc0f48 100644 > --- a/Documentation/features/sched/membarrier-sync-core/arch-support.txt > +++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt > @@ -10,6 +10,22 @@ > # Rely on implicit context synchronization as a result of exception return > # when returning from IPI handler, and when returning to user-space. > # > +# * riscv > +# > +# riscv uses xRET as return from interrupt and to return to user-space. > +# > +# Given that xRET is not core serializing, we rely on FENCE.I for providing > +# core serialization: > +# > +# - by calling sync_core_before_usermode() on return from interrupt (cf. > +# ipi_sync_core()), > +# > +# - via switch_mm() and sync_core_before_usermode() (respectively, for > +# uthread->uthread and kthread->uthread transitions) to go back to > +# user-space. I don't quite get the meaning of the sentence above. There seems to be a missing marker before "to go back". Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv