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 E4C3EC433FE for ; Tue, 4 Jan 2022 15:55:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235163AbiADPzl (ORCPT ); Tue, 4 Jan 2022 10:55:41 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:33410 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235183AbiADPzW (ORCPT ); Tue, 4 Jan 2022 10:55:22 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: kholk11) with ESMTPSA id 807461F43593 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1641311721; bh=V052X6CDRqGtUFJ9/x/emU0xn91Fbjw/PEV/sXPRzeQ=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=DONGLC2hY7afAnjU2pD69F6yoQtckqgDyfVXGrV9S7yr4nBspBHhjw+C5Y7ZfSRD6 pcy60TFAq9Gjd8ObWJUnIkyC3zKY8Ef47nQx9V7caoOiCp3L4HPd+VWVS7wttJrZI5 xyhlyiQ8aOFEk4edgoHX+3zuRvz98P58oOa2Sq8up9fu5YN5qUyYbnJ2e1bk03QfBS yepEvPax+fe1PvQDBmdlvyGBxehQxCOn+OufgkQuwWjPMUSn1XC31TN1wAIsYqS2oD D/fSKoZsUKhuSPi86VkYTS7fq80pyNf1t3DYDePF8KHSV7Kk6FRneoroyM9WRpbcNu yL3AUJ3Z3bKpA== Subject: Re: [PATCH v3 09/33] iommu/mediatek: Remove for_each_m4u in tlb_sync_all To: Yong Wu , Joerg Roedel , Rob Herring , Matthias Brugger , Will Deacon , Robin Murphy Cc: Krzysztof Kozlowski , Tomasz Figa , linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, Hsin-Yi Wang , youlin.pei@mediatek.com, anan.sun@mediatek.com, chao.hao@mediatek.com, yen-chang.chen@mediatek.com References: <20210923115840.17813-1-yong.wu@mediatek.com> <20210923115840.17813-10-yong.wu@mediatek.com> From: AngeloGioacchino Del Regno Message-ID: Date: Tue, 4 Jan 2022 16:55:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210923115840.17813-10-yong.wu@mediatek.com> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 23/09/21 13:58, Yong Wu ha scritto: > The tlb_sync_all is called from these three functions: > a) flush_iotlb_all: it will be called for each a iommu HW. > b) tlb_flush_range_sync: it already has for_each_m4u. > c) in irq: When IOMMU HW translation fault, Only need flush itself. > > Thus, No need for_each_m4u in this tlb_sync_all. Remove it. > > Signed-off-by: Yong Wu > --- > drivers/iommu/mtk_iommu.c | 18 +++++++----------- > 1 file changed, 7 insertions(+), 11 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index 6f4f6624e3ac..0b4c30baa864 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -206,19 +206,15 @@ static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom) > > static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data) > { > - struct list_head *head = data->hw_list; > - > - for_each_m4u(data, head) { > - if (pm_runtime_get_if_in_use(data->dev) <= 0) > - continue; > + if (pm_runtime_get_if_in_use(data->dev) <= 0) > + return; > > - writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > - data->base + data->plat_data->inv_sel_reg); > - writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); > - wmb(); /* Make sure the tlb flush all done */ > + writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > + data->base + data->plat_data->inv_sel_reg); > + writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); > + wmb(); /* Make sure the tlb flush all done */ There aren't a lot of writes here - not anymore, since you are no longer doing this for_each_m4u()... ...so, please change writel_relaxed() to writel() calls, allowing you to also remove the write barrier at the end (since in the non relaxed version, order is already ensured). > > - pm_runtime_put(data->dev); > - } > + pm_runtime_put(data->dev); > } > > static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size, >