[PATCH] ocxl: Mmio invalidation support

[Andrew Donnellan]

On 14/11/20 2:33 am, Christophe Lombard wrote:
> OpenCAPI 4.0/5.0 with TLBI/SLBI Snooping, is not used due to performance
> problems caused by the PAU having to process all incoming TLBI/SLBI
> commands which will cause them to back up on the PowerBus.
> 
> When the Address Translation Mode requires TLB and SLB Invalidate
> operations to be initiated using MMIO registers, a set of registers like
> the following is used:
> • XTS MMIO ATSD0 LPARID register
> • XTS MMIO ATSD0 AVA register
> • XTS MMIO ATSD0 launch register, write access initiates a shoot down
> • XTS MMIO ATSD0 status register
> 
> The MMIO based mechanism also blocks the NPU/PAU from snooping TLBIE
> commands from the PowerBus.
> 
> The Shootdown commands (ATSD) will be generated using MMIO registers
> in the NPU/PAU and sent to the device.
> 
> Signed-off-by: Christophe Lombard <clombard at linux.vnet.ibm.com>

snowpatch has reported some minor checkpatch issues: 
https://openpower.xyz/job/snowpatch/job/snowpatch-linux-checkpatch/16267//artifact/linux/checkpatch.log

-- 
Andrew Donnellan              OzLabs, ADL Canberra
ajd at linux.ibm.com             IBM Australia Limited