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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 9CA45C47E49 for ; Wed, 23 Oct 2019 16:55:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 721C721928 for ; Wed, 23 Oct 2019 16:55:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571849752; bh=VPyPC4LePKk7uWBltRmK/Fded+OjFkz/1MBUzjK69yE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=URXDyMr2WYR0fPdWYNsQ5L5irtcF3zLJzEMk3xQj6OBpvUnv9IXN0KJsMzJ+/o/vY bnICj9XDV1qNAjjdNxuWVloSVms9jnb3K4K+3+RnwPhYdp/nrGWi6O/By1Mtgv87lT yHhCIOGWwA/2KVThJW/ioKRpiBaO6D+17HTdwFkE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726619AbfJWQzv (ORCPT ); Wed, 23 Oct 2019 12:55:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:34346 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726265AbfJWQzu (ORCPT ); Wed, 23 Oct 2019 12:55:50 -0400 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 255AC21906; Wed, 23 Oct 2019 16:55:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571849750; bh=VPyPC4LePKk7uWBltRmK/Fded+OjFkz/1MBUzjK69yE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=F6EnkV+NncnzhwMOW6V6hkw45lZgsqg3/2TZtCGHZozEzQIq3KdMfSDzhP1HG7DEk M7mlDDT1+IBGeBeN7wjqNdxT1gyRg8gcrMld2vzIAOeKMgU6M5qaR4w4RXQRM3f8MR nDVUOk8sxVo9dbcnWMOHzMooezkVxez8zgQU2eWs= Date: Wed, 23 Oct 2019 17:55:44 +0100 From: Will Deacon To: Yong Wu Cc: Matthias Brugger , Joerg Roedel , Will Deacon , Evan Green , Robin Murphy , Tomasz Figa , linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, youlin.pei@mediatek.com, Nicolas Boichat , anan.sun@mediatek.com, cui.zhang@mediatek.com, chao.hao@mediatek.com, edison.hsieh@mediatek.com Subject: Re: [PATCH v4 3/7] iommu/mediatek: Use gather to achieve the tlb range flush Message-ID: <20191023165543.GB27471@willie-the-truck> References: <1571196792-12382-1-git-send-email-yong.wu@mediatek.com> <1571196792-12382-4-git-send-email-yong.wu@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1571196792-12382-4-git-send-email-yong.wu@mediatek.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 Wed, Oct 16, 2019 at 11:33:08AM +0800, Yong Wu wrote: > Use the iommu_gather mechanism to achieve the tlb range flush. > Gather the iova range in the "tlb_add_page", then flush the merged iova > range in iotlb_sync. > > Suggested-by: Tomasz Figa > Signed-off-by: Yong Wu > --- > drivers/iommu/mtk_iommu.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index c2f6c78..81ac95f 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -245,11 +245,9 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather, > void *cookie) > { > struct mtk_iommu_data *data = cookie; > - unsigned long flags; > + struct iommu_domain *domain = &data->m4u_dom->domain; > > - spin_lock_irqsave(&data->tlb_lock, flags); > - mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie); > - spin_unlock_irqrestore(&data->tlb_lock, flags); > + iommu_iotlb_gather_add_page(domain, gather, iova, granule); You need to be careful here, because iommu_iotlb_gather_add_page() can call iommu_tlb_sync() in some situations and you don't hold the lock. > static const struct iommu_flush_ops mtk_iommu_flush_ops = { > @@ -469,9 +467,15 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, > struct iommu_iotlb_gather *gather) > { > struct mtk_iommu_data *data = mtk_iommu_get_m4u_data(); > + size_t length = gather->end - gather->start; > unsigned long flags; > > + if (gather->start == ULONG_MAX) > + return; > + > spin_lock_irqsave(&data->tlb_lock, flags); > + mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize, > + false, data); > mtk_iommu_tlb_sync(data); > spin_unlock_irqrestore(&data->tlb_lock, flags); Modulo my comment above, this fixes my previous comment. Given that mainline is already broken, I guess the runtime bisectability isn't a problem. Will