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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 66A4BC433EF for ; Wed, 22 Dec 2021 11:26:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244654AbhLVL0o (ORCPT ); Wed, 22 Dec 2021 06:26:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244647AbhLVL0g (ORCPT ); Wed, 22 Dec 2021 06:26:36 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6CC8EC061574; Wed, 22 Dec 2021 03:26:35 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2F421B81A4F; Wed, 22 Dec 2021 11:26:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2738C36AE5; Wed, 22 Dec 2021 11:26:30 +0000 (UTC) From: Catalin Marinas To: will@kernel.org, Xiongfeng Wang , corbet@lwn.net, mark.rutland@arm.com, peterz@infradead.org Cc: moyufeng@huawei.com, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] asm-generic: introduce io_stop_wc() and add implementation for ARM64 Date: Wed, 22 Dec 2021 11:26:28 +0000 Message-Id: <164017237365.157899.5054701495946891448.b4-ty@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211221035556.60346-1-wangxiongfeng2@huawei.com> References: <20211221035556.60346-1-wangxiongfeng2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 21 Dec 2021 11:55:56 +0800, Xiongfeng Wang wrote: > For memory accesses with write-combining attributes (e.g. those returned > by ioremap_wc()), the CPU may wait for prior accesses to be merged with > subsequent ones. But in some situation, such wait is bad for the > performance. > > We introduce io_stop_wc() to prevent the merging of write-combining > memory accesses before this macro with those after it. > > [...] Applied to arm64 (for-next/misc), thanks! [1/1] asm-generic: introduce io_stop_wc() and add implementation for ARM64 https://git.kernel.org/arm64/c/d5624bb29f49 -- Catalin