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Subject: Re: [PATCH] irq/gic-its: gicv4: set VPENDING table as inner-shareable
To:     Marc Zyngier <maz@kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <wanghaibin.wang@huawei.com>,
        "Thomas Gleixner" <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>
References: <20191130073849.38378-1-guoheyi@huawei.com>
 <20191201180434.1dba3116@why>
 <3de7a72f-1a15-c908-57e6-35eff00b1ca6@huawei.com>
 <40704a28b562167b58992c036bff4f81@kernel.org>
From:   Heyi Guo <guoheyi@huawei.com>
Message-ID: <517af92f-4e15-6b88-fe2e-e76e2db7234e@huawei.com>
Date:   Mon, 30 Mar 2020 08:39:57 +0800
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On 2020/3/21 17:54, Marc Zyngier wrote:
> Hi Heyi,
>
> On 2020-02-24 02:22, Heyi Guo wrote:
>> Hi Marc,
>>
>> On 2019/12/2 2:04, Marc Zyngier wrote:
>>> On Sat, 30 Nov 2019 15:38:49 +0800
>>> Heyi Guo <guoheyi@huawei.com> wrote:
>>>
>>>> There is no special reason to set virtual LPI pending table as
>>>> non-shareable. If we choose to hard code the shareability without
>>>> probing, inner-shareable will be a better choice, for all the other
>>>> ITS/GICR tables prefer to be inner-shareable.
>>> One of the issues is that we have strictly no idea what the caches are
>>> Inner Shareable with (I've been asking for such clarification for years
>>> without getting anywhere). You can have as many disconnected inner
>>> shareable domains as you want!
>>>
>>> I suspect that in the grand scheme of things, the redistributors
>>> ought to be in the same inner shareable domain, and that with a bit of
>>> luck, the CPUs are there as well. Still, that's a massive guess.
>>>
>>>> What's more, on Hisilicon hip08 it will trigger some kind of bus
>>>> warning when mixing use of different shareabilities.
>>> Do you have more information about what the bus is complaining about?
>>> Is that because the CPUs have these pages mapped as inner shareable?
>>>
>>> I'll give it a go on D05 (HIP07) to find out what changes there.
>>
>> How's your go on D05? Did you see any issues?
>
> Sorry it took so long. I've given it a go on my D05, and didn't notice
> anything bad (or rather, nothing worse than usual, since GICv4 on this
> machine is pretty... funky).
>
> I've now take this into the 5.7 queue.


Thanks,

Heyi


>
> Thanks,
>
>          M.