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Subject: Re: [PATCH 4/4] crypto: hisilicon/sec2 - Add pbuffer mode for SEC
 driver
To:     Xu Zaibo <xuzaibo@huawei.com>, <herbert@gondor.apana.org.au>,
        <davem@davemloft.net>
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        <forest.zhouchang@huawei.com>, <linuxarm@huawei.com>,
        <zhangwei375@huawei.com>, <shenyang39@huawei.com>,
        <yekai13@huawei.com>, <linux-crypto@vger.kernel.org>
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From:   John Garry <john.garry@huawei.com>
Message-ID: <87591c1f-5c6b-64bd-5dc2-900e1481b5ca@huawei.com>
Date:   Thu, 20 Feb 2020 11:07:08 +0000
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On 20/02/2020 10:10, Xu Zaibo wrote:
> Hi,
> 
> 
> On 2020/2/20 17:50, John Garry wrote:
>> On 20/02/2020 09:04, Zaibo Xu wrote:
>>> From: liulongfang <liulongfang@huawei.com>
>>>
>>> In the scenario of SMMU translation, the SEC performance of short 
>>> messages
>>> (<512Bytes) cannot meet our expectations. To avoid this, we reserve the
>>> plat buffer (PBUF) memory for small packets when creating TFM.
>>>
>>
>> I haven't gone through the code here, but why not use this method also 
>> for non-translated? What are the pros and cons?
> Because non-translated has no performance or throughput problems.
> 

OK, so no problem, but I was asking could it be improved, and, if so, 
what would be the drawbacks?

As for the change to check if the IOMMU is translating, it seems exact 
same as that for the hi1616 driver...

> cheers,
> Zaibo
> 
> .
>>
>> The commit message is very light on details.
>>
>> Thanks
>> john
>>
>> .
>>
> 
> 
> .