[PING][PATCHv3 1/2] aarch64: Hoist ZVA check out of the memset function

[Wilco Dijkstra]

Adhemerval Zanella wrote:

> My idea is to prevent have different code paths in different files that
> are 'injected' by macros or ifdefs.  Getting all of them in one place is
> better imho than spread over multiple files.  Now, what you are advocating
> is a different topic: whether the modifications of the generic
> implementation are valuable.

Well I'm talking about the patch as proposed. I can no longer understand
the order or the logic, and it is impossible to figure out which of the many
possible cases may have changed alignment of the code - whether by
accident or on purpose.

> Ideally it would prefer to have a more concise selection as:
>
>   1. A memset that reads dczid_el0 using mrs (as the default one).
>      This will be selected as default and thus should not incur in any
>      regression.
>
>   2. A memset that reads the zva size from global variable and is selected
>      solely by falkor (and ideally it would handle 64 and 128 cacheline
>      sizes).
>
>   3. no zva variant in the case of zva being 0.

I don't see how that makes sense. If we decide to use an ifunc, then you
no longer need to check the ZVA size. So I just don't understand why we
need a global at all...

Wilco