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Subject: Re: [PATCH v4 5/7] iommu/io-pgtable: Allow io_pgtable_tlb ops
 optional
To:     Yong Wu <yong.wu@mediatek.com>, Joerg Roedel <joro@8bytes.org>,
        Will Deacon <will@kernel.org>
Cc:     Matthias Brugger <matthias.bgg@gmail.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Tomasz Figa <tfiga@google.com>,
        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 <drinkcat@chromium.org>, anan.sun@mediatek.com,
        chao.hao@mediatek.com, Greg Kroah-Hartman <gregkh@google.com>,
        kernel-team@android.com, Christoph Hellwig <hch@infradead.org>,
        David Laight <David.Laight@ACULAB.COM>
References: <20210107122909.16317-1-yong.wu@mediatek.com>
 <20210107122909.16317-6-yong.wu@mediatek.com>
From:   Robin Murphy <robin.murphy@arm.com>
Message-ID: <9b51058a-f636-e2b3-b5ee-0b48e4bccfc9@arm.com>
Date:   Mon, 18 Jan 2021 18:42:42 +0000
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On 2021-01-07 12:29, Yong Wu wrote:
> This patch allows io_pgtable_tlb ops could be null since the IOMMU drivers
> may use the tlb ops from iommu framework.

For the reasons I gave on v3,

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
>   include/linux/io-pgtable.h | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
> index ea727eb1a1a9..2a5686ca2ba3 100644
> --- a/include/linux/io-pgtable.h
> +++ b/include/linux/io-pgtable.h
> @@ -214,14 +214,16 @@ struct io_pgtable_domain_attr {
>   
>   static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
>   {
> -	iop->cfg.tlb->tlb_flush_all(iop->cookie);
> +	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_all)
> +		iop->cfg.tlb->tlb_flush_all(iop->cookie);
>   }
>   
>   static inline void
>   io_pgtable_tlb_flush_walk(struct io_pgtable *iop, unsigned long iova,
>   			  size_t size, size_t granule)
>   {
> -	iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
> +	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_walk)
> +		iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
>   }
>   
>   static inline void
> @@ -229,7 +231,7 @@ io_pgtable_tlb_add_page(struct io_pgtable *iop,
>   			struct iommu_iotlb_gather * gather, unsigned long iova,
>   			size_t granule)
>   {
> -	if (iop->cfg.tlb->tlb_add_page)
> +	if (iop->cfg.tlb && iop->cfg.tlb->tlb_add_page)
>   		iop->cfg.tlb->tlb_add_page(gather, iova, granule, iop->cookie);
>   }
>   
>