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,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_2 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 0F287ECE58E for ; Tue, 8 Oct 2019 08:18:43 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D5DDC21721 for ; Tue, 8 Oct 2019 08:18:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5DDC21721 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id A4E23B49; Tue, 8 Oct 2019 08:18:42 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 26EC541C for ; Tue, 8 Oct 2019 08:18:42 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mailgw02.mediatek.com (unknown [1.203.163.81]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 7A8185D3 for ; Tue, 8 Oct 2019 08:18:39 +0000 (UTC) X-UUID: 0b511a8e3bf04a068a8709439614994f-20191008 X-UUID: 0b511a8e3bf04a068a8709439614994f-20191008 Received: from mtkcas36.mediatek.inc [(172.27.4.253)] by mailgw02.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 1743715037; Tue, 08 Oct 2019 16:18:35 +0800 Received: from MTKCAS32.mediatek.inc (172.27.4.184) by MTKMBS31N1.mediatek.inc (172.27.4.69) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 8 Oct 2019 16:18:33 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS32.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Tue, 8 Oct 2019 16:18:32 +0800 Message-ID: <1570522712.19130.42.camel@mhfsdcap03> Subject: Re: [PATCH] iommu/mediatek: Move the tlb_sync into tlb_flush From: Yong Wu To: Will Deacon Date: Tue, 8 Oct 2019 16:18:32 +0800 In-Reply-To: <20190930120926.t26ydhgggi2scg3e@willie-the-truck> References: <1569822142-14303-1-git-send-email-yong.wu@mediatek.com> <20190930120926.t26ydhgggi2scg3e@willie-the-truck> X-Mailer: Evolution 3.10.4-0ubuntu2 MIME-Version: 1.0 X-TM-SNTS-SMTP: 7D17782CEA9D438245218EEEE6BBEC1C3BB60458E15FE650459FFB65E1DB5FFA2000:8 X-MTK: N Cc: youlin.pei@mediatek.com, anan.sun@mediatek.com, Nicolas Boichat , cui.zhang@mediatek.com, srv_heupstream@mediatek.com, Tomasz Figa , Will Deacon , linux-kernel@vger.kernel.org, Evan Green , chao.hao@mediatek.com, iommu@lists.linux-foundation.org, linux-mediatek@lists.infradead.org, Matthias Brugger , Robin Murphy , linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Mon, 2019-09-30 at 13:09 +0100, Will Deacon wrote: > On Mon, Sep 30, 2019 at 01:42:22PM +0800, Yong Wu wrote: > > The commit 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API > > TLB sync") help move the tlb_sync of unmap from v7s into the iommu > > framework. It helps add a new function "mtk_iommu_iotlb_sync", But it > > lacked the dom->pgtlock, then it will cause the variable > > "tlb_flush_active" may be changed unexpectedly, we could see this warning > > log randomly: > > > > mtk-iommu 10205000.iommu: Partial TLB flush timed out, falling back to > > full flush > > > > To fix this issue, we can add dom->pgtlock in the "mtk_iommu_iotlb_sync". > > And when checking this issue, we find that __arm_v7s_unmap call > > io_pgtable_tlb_add_flush consecutively when it is supersection/largepage, > > this also is potential unsafe for us. There is no tlb flush queue in the > > MediaTek M4U HW. The HW always expect the tlb_flush/tlb_sync one by one. > > If v7s don't always gurarantee the sequence, Thus, In this patch I move > > the tlb_sync into tlb_flush(also rename the function deleting "_nosync"). > > and we don't care if it is leaf, rearrange the callback functions. Also, > > the tlb flush/sync was already finished in v7s, then iotlb_sync and > > iotlb_sync_all is unnecessary. > > > > Besides, there are two minor changes: > > a) Use writel for the register F_MMU_INV_RANGE which is for triggering the > > HW work. We expect all the setting(iova_start/iova_end...) have already > > been finished before F_MMU_INV_RANGE. > > b) Reduce the tlb timeout value from 100000us to 1000us. the original value > > is so long that affect the multimedia performance. > > > > Fixes: 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API TLB sync") > > Signed-off-by: Chao Hao > > Signed-off-by: Yong Wu > > --- > > This patch looks break the logic for tlb_flush and tlb_sync. I'm not > > sure if it > > is reasonable. If someone has concern, I could change: > > a) Add dom->pgtlock in the mtk_iommu_iotlb_sync > > b) Add a io_pgtable_tlb_sync in [1]. > > The patch looks ok to me, but please could you split it up so that the > timeout and writel are done separately? Thanks for the quick review, I will separate them. > > Thanks, > > Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu