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Cc:     baolu.lu@linux.intel.com, iommu@lists.linux-foundation.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        suravee.suthikulpanit@amd.com, john.garry@huawei.com,
        dianders@chromium.org
Subject: Re: [PATCH v2 13/24] iommu/dma: Remove redundant "!dev" checks
To:     Robin Murphy <robin.murphy@arm.com>, joro@8bytes.org,
        will@kernel.org
References: <cover.1627468308.git.robin.murphy@arm.com>
 <200af1d10b493a90aada6466b1f1938e1b16731f.1627468309.git.robin.murphy@arm.com>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <32647590-5957-5a54-71ed-fa6e6f2b1a5b@linux.intel.com>
Date:   Fri, 30 Jul 2021 14:08:01 +0800
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On 7/28/21 11:58 PM, Robin Murphy wrote:
> iommu_dma_init_domain() is now only called from iommu_setup_dma_ops(),
> which has already assumed dev to be non-NULL.
> 
> Reviewed-by: John Garry <john.garry@huawei.com>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>   drivers/iommu/dma-iommu.c | 5 +----
>   1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 10067fbc4309..e28396cea6eb 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -363,7 +363,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>   
>   	init_iova_domain(iovad, 1UL << order, base_pfn);
>   
> -	if (!cookie->fq_domain && (!dev || !dev_is_untrusted(dev)) &&
> +	if (!cookie->fq_domain && !dev_is_untrusted(dev) &&
>   	    domain->ops->flush_iotlb_all && !iommu_get_dma_strict(domain)) {
>   		if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
>   					  iommu_dma_entry_dtor))
> @@ -372,9 +372,6 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>   			cookie->fq_domain = domain;
>   	}
>   
> -	if (!dev)
> -		return 0;
> -
>   	return iova_reserve_iommu_regions(dev, domain);
>   }
>   
> 


Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu