Re: [RFC PATCH 0/3] Add a new flag for ITS device to control indirect route

majun (Euler7)
2016-12-02T09:30:24Z

在 2016/12/1 17:07, Marc Zyngier 写道:
> On 01/12/16 07:45, Majun wrote:
>> From: MaJun <majun258@huawei.com>
>>
>> For current ITS driver, two level table (indirect route) is enabled when the memory used
>> for LPI route table over the limit(64KB * 2) size. But this function impact the
>> performance of LPI interrupt actually because need more time to look up the table.
>
> Are you implying that your ITS doesn't have a cache to lookup the most
> active devices, hence performing a full lookup on each interrupt?

Our ITS chip has the cache with depth 64. But this seems not enough for some
scenario,espeically on virtulization platform.
>
> Anyway, doing this as a DT quirk doesn't feel right. Please use the ITS
> quirk infrastructure.

If there is no other better solutions, I will do this.

Thanks!
Majun

>
> Thanks,
>
> M.
>