Re: [PATCH] ocxl: Mmio invalidation support
From: Andrew Donnellan <hidden>
Date: 2020-11-17 00:43:32
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 <redacted>
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@linux.ibm.com IBM Australia Limited