linux-kernel - Re: [PATCH v3 4/7] iommu/mediatek: Delete the leaf in the tlb flush

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Date:   Tue, 15 Oct 2019 12:24:01 +0100
From:   Robin Murphy <robin.murphy@....com>
To:     Yong Wu <yong.wu@...iatek.com>
Cc:     Matthias Brugger <matthias.bgg@...il.com>,
        Joerg Roedel <joro@...tes.org>,
        Will Deacon <will.deacon@....com>, youlin.pei@...iatek.com,
        anan.sun@...iatek.com, Nicolas Boichat <drinkcat@...omium.org>,
        cui.zhang@...iatek.com, srv_heupstream@...iatek.com,
        chao.hao@...iatek.com, edison.hsieh@...iatek.com,
        linux-kernel@...r.kernel.org, Evan Green <evgreen@...omium.org>,
        Tomasz Figa <tfiga@...gle.com>,
        iommu@...ts.linux-foundation.org,
        linux-mediatek@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v3 4/7] iommu/mediatek: Delete the leaf in the tlb flush

On 15/10/2019 06:25, Yong Wu wrote:
> On Mon, 2019-10-14 at 15:22 +0100, Robin Murphy wrote:
>> On 14/10/2019 07:38, Yong Wu wrote:
>>> In our tlb range flush, we don't care the "leaf". Remove it to simplify
>>> the code. no functional change.
>>
>> Presumably you don't care about the granule either?
> 
> Yes. I only keep "granule" to satisfy the format of "tlb_flush_walk",
> then it's no need add a new helper function.

Ah, I'd failed to make the connection that it ends up wired in directly 
to the callbacks in patch #5 - indeed there's no point churning the 
mtk_iommu_tlb_add_flush_nosync() callsites here if they're just getting 
removed later anyway. In that case,

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

>>> Signed-off-by: Yong Wu <yong.wu@...iatek.com>
>>> ---
>>>    drivers/iommu/mtk_iommu.c | 16 ++++------------
>>>    1 file changed, 4 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
>>> index 8712afc..19f936c 100644
>>> --- a/drivers/iommu/mtk_iommu.c
>>> +++ b/drivers/iommu/mtk_iommu.c
>>> @@ -174,8 +174,7 @@ static void mtk_iommu_tlb_flush_all(void *cookie)
>>>    }
>>>    
>>>    static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
>>> -					   size_t granule, bool leaf,
>>> -					   void *cookie)
>>> +					   size_t granule, void *cookie)
>>>    {
>>>    	struct mtk_iommu_data *data = cookie;
>>>    
>>> @@ -219,14 +218,7 @@ static void mtk_iommu_tlb_sync(void *cookie)
>>>    static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size,
>>>    				     size_t granule, void *cookie)
>>>    {
>>> -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, false, cookie);
>>> -	mtk_iommu_tlb_sync(cookie);
>>> -}
>>> -
>>> -static void mtk_iommu_tlb_flush_leaf(unsigned long iova, size_t size,
>>> -				     size_t granule, void *cookie)
>>> -{
>>> -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, true, cookie);
>>> +	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, cookie);
>>>    	mtk_iommu_tlb_sync(cookie);
>>>    }
>>>    
>>> @@ -245,7 +237,7 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
>>>    static const struct iommu_flush_ops mtk_iommu_flush_ops = {
>>>    	.tlb_flush_all = mtk_iommu_tlb_flush_all,
>>>    	.tlb_flush_walk = mtk_iommu_tlb_flush_walk,
>>> -	.tlb_flush_leaf = mtk_iommu_tlb_flush_leaf,
>>> +	.tlb_flush_leaf = mtk_iommu_tlb_flush_walk,
>>>    	.tlb_add_page = mtk_iommu_tlb_flush_page_nosync,
>>>    };
>>>    
>>> @@ -475,7 +467,7 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
>>>    		spin_lock_irqsave(&dom->pgtlock, flags);
>>>    
>>>    	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
>>> -				       false, data);
>>> +				       data);
>>>    	mtk_iommu_tlb_sync(data);
>>>    
>>>    	if (!is_in_gather)
>>>
>>
>> _______________________________________________
>> Linux-mediatek mailing list
>> Linux-mediatek@...ts.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-mediatek
> 
> 

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