[PATCH] drivers/perf: hisi: Add identifier sysfs file

[John Garry]

Hi Will,

> 
> On Wed, Jun 17, 2020 at 09:05:11PM +0800, John Garry wrote:
>> To allow userspace to identify the specific implementation of the device,
>> add an "identifier" sysfs file.
>>
>> Encoding is as follows:
>> hi1620: 0x0	(aka hip08)
>> hi1630: 0x30
>>
>> Signed-off-by: John Garry <john.garry at huawei.com>
> 
> I'm struggling a bit to track this. If you still think it's worth pursuing,
> please could you post a series with a cover-letter describing what this is
> for, a link to the userspace changes and then patches for all the PMU
> drivers that need updating? 

There is no hi1630 userspace support yet.

So what I can do is post updated userspace support (including hi1630), 
and then post kernel parts together for all drivers we could initially 
support.

@Joakim, I'll pick your imx driver changes here, if you don't mind.

There was an RFC from you for the SMMUv3 PMU as
> well, and also some other "arm64" changes.
> 

I hope to drop that RFC if an updated SMMUv3 spec helps us out.

Cheers,
John