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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 8D4FBC433DF for ; Fri, 22 May 2020 15:50:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68F4C205CB for ; Fri, 22 May 2020 15:50:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730534AbgEVPuK (ORCPT ); Fri, 22 May 2020 11:50:10 -0400 Received: from foss.arm.com ([217.140.110.172]:38408 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730058AbgEVPuJ (ORCPT ); Fri, 22 May 2020 11:50:09 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1D76F55D; Fri, 22 May 2020 08:50:09 -0700 (PDT) Received: from gaia (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CB27D3F305; Fri, 22 May 2020 08:50:05 -0700 (PDT) Date: Fri, 22 May 2020 16:50:02 +0100 From: Catalin Marinas To: Zhenyu Ye Cc: peterz@infradead.org, mark.rutland@arm.com, will@kernel.org, aneesh.kumar@linux.ibm.com, akpm@linux-foundation.org, npiggin@gmail.com, arnd@arndb.de, rostedt@goodmis.org, maz@kernel.org, suzuki.poulose@arm.com, tglx@linutronix.de, yuzhao@google.com, Dave.Martin@arm.com, steven.price@arm.com, broonie@kernel.org, guohanjun@huawei.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, arm@kernel.org, xiexiangyou@huawei.com, prime.zeng@hisilicon.com, zhangshaokun@hisilicon.com, kuhn.chenqun@huawei.com Subject: Re: [PATCH v2 1/6] arm64: Detect the ARMv8.4 TTL feature Message-ID: <20200522155002.GF26492@gaia> References: <20200423135656.2712-1-yezhenyu2@huawei.com> <20200423135656.2712-2-yezhenyu2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200423135656.2712-2-yezhenyu2@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 23, 2020 at 09:56:51PM +0800, Zhenyu Ye wrote: > From: Marc Zyngier > > In order to reduce the cost of TLB invalidation, the ARMv8.4 TTL > feature allows TLBs to be issued with a level allowing for quicker > invalidation. > > The TTL field indicates the level of page table walk > holding the leaf entry for the address being invalidated. > > Let's detect the feature for now. Further patches will implement > its actual usage. > > Signed-off-by: Marc Zyngier > Signed-off-by: Zhenyu Ye Reviewed-by: Catalin Marinas