[PATCH v4 01/26] arm64/cpuinfo: Restore define for AIVIVT cache type

[Mark Brown]

On Wed, Jun 22, 2022 at 12:09:33PM +0100, Mark Rutland wrote:
> On Mon, Jun 20, 2022 at 01:43:42PM +0100, Mark Brown wrote:
> > In 155433cb365ee466 ("arm64: cache: Remove support for ASID-tagged VIVT
> > I-caches") we removed all the support fir AIVIVT cache types and renamed
> > all references to the field to say "unknown" since support for AIVIVT
> > caches was removed from the architecture. Since the correspoding removal

> I'm not too keen on this, becuase architecturally AIVIVT does not exist in
> ARMv8, and the real bug here is that the ARM ARM still calls this AIVIVT rather
> than saying it's reserved.

Yes, it's rather difficult to divine the intent of the architecture here
- I was erring on the side of the name having been left there for *some*
reason, though equally it could just be done that way to ensure nobody
confuses things by trying to allocate what looks like a previously
reserved value in future.

> > -#define ICACHE_POLICY_RESERVED	1
> > +#define ICACHE_POLICY_AIVIVT	1

> How about we just delete ICACHE_POLICY_RESERVED entirely...

Sure.

> ... then in subsequent patches we don't need to define a bogus
> ICACHE_POLICY_AIVIVT value in the scripted headers.

I think if we don't have the value be the same as it is in the
architecture we're going to have the next person who happens to look at
this go and try to define the missing value again.  I suppose we can add
a comment in the text file...
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20220622/7611da1b/attachment-0001.sig>