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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 A9ECBC04AB1 for ; Thu, 9 May 2019 08:57:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76D28216C4 for ; Thu, 9 May 2019 08:57:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726411AbfEII5L (ORCPT ); Thu, 9 May 2019 04:57:11 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:34532 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725821AbfEII5L (ORCPT ); Thu, 9 May 2019 04:57:11 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 15E61F77F8BDA0A382E3; Thu, 9 May 2019 16:57:09 +0800 (CST) Received: from [127.0.0.1] (10.177.31.55) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Thu, 9 May 2019 16:57:02 +0800 Subject: Re: Why do we mark vpending table as non-shareable in GICR_VPENDBASER? To: Marc Zyngier References: <867eb09i00.wl-marc.zyngier@arm.com> CC: , Christoffer Dall , wanghaibin 00208455 From: Heyi Guo Message-ID: <63414d91-2ddf-e1bb-22cf-3eb00e355fba@huawei.com> Date: Thu, 9 May 2019 16:56:57 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <867eb09i00.wl-marc.zyngier@arm.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.31.55] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks. One more question about the cacheability of VPROPBASER, which is RaWb, while it is RaWaWb for PROPBASER. Any special reason for this? Heyi On 2019/5/9 15:58, Marc Zyngier wrote: > On Thu, 09 May 2019 08:10:09 +0100, > Heyi Guo wrote: >> Hi Marc, >> >> We can see in its_vpe_schedule() the shareability bits of >> GICR_VPENDBASER are set as non-shareable, But we set physical >> PENDBASER as inner-shareable. Is there any special reason for doing >> this? If it is because the vpending table is GICR specific, why >> don't we do the same for physical pending table? > That's a good question. They should have similar attributes. > >> We have not seen function issue with this setting, but a special >> detector in our hardware warns us that there are non-shareable >> requests sent out while some inner shareable cache entries still >> present in the cache, and it may cause data inconsistent. > The main issue with the inner-shareable attributes and the GIC is that > nothing in the spec says that CPUs and GIC have to be in the same > inner-shareable domain, as the system can have as many as you want. > > You obviously have built it with GICR in the same inner-shareability > domain as the CPU. I'm happy to change the VPENDBASER attributes, > given that the CPU has a mapping to that memory already, and that > shouldn't affect systems where GICR isn't in the same inner shareable > domain anyway. > > Thanks, > > M. >