Re: [PATCH v2] sparc64: Add support for Application Data Integrity (ADI)

From: Khalid Aziz
Date: Mon Mar 07 2016 - 18:28:57 EST


On 03/07/2016 04:12 PM, Rob Gardner wrote:
On 03/07/2016 01:33 PM, Khalid Aziz wrote:

That is a possibility but limited in scope. An address range covered
by a single TTE can have large number of tags. Version tags are set on
cacheline. In extreme case, one could set a tag for each set of
64-bytes in a page. Also tags are set completely in userspace and no
transition occurs to kernel space, so kernel has no idea of what tags
have been set.

...
I have not found a way to query the MMU on tags.


To query the tag for a cache line, you just read it back with ldxa and
ASI_MCD_PRIMARY (ie, asi 0x90), basically the same way you stored the
tag in the first place.


Thanks, Rob. I just saw it while reading through the manual.

--
Khalid