Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 23 Dec 2020 08:51:53 +0000
From:   Christoph Hellwig <hch@infradead.org>
To:     Yong Wu <yong.wu@mediatek.com>
Cc:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>, youlin.pei@mediatek.com,
        anan.sun@mediatek.com, Nicolas Boichat <drinkcat@chromium.org>,
        srv_heupstream@mediatek.com, chao.hao@mediatek.com,
        linux-kernel@vger.kernel.org,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Tomasz Figa <tfiga@google.com>,
        iommu@lists.linux-foundation.org,
        linux-mediatek@lists.infradead.org,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Greg Kroah-Hartman <gregkh@google.com>,
        kernel-team@android.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 1/7] iommu: Move iotlb_sync_map out from __iommu_map
Message-ID: <20201223085153.GA30643@infradead.org>
References: <20201216103607.23050-1-yong.wu@mediatek.com>
 <20201216103607.23050-2-yong.wu@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20201216103607.23050-2-yong.wu@mediatek.com>
Precedence: bulk

On Wed, Dec 16, 2020 at 06:36:01PM +0800, Yong Wu wrote:
> In the end of __iommu_map, It alway call iotlb_sync_map.
> This patch moves iotlb_sync_map out from __iommu_map since it is
> unnecessary to call this for each sg segment especially iotlb_sync_map
> is flush tlb all currently.
> 
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> Reviewed-by: Robin Murphy <robin.murphy@arm.com>

What about adding a little helper that does the NULL check and method
call instead of duplicating it all over?