From: Andrew Donnellan <ajd@linux.ibm.com>
To: Christophe Lombard <clombard@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org, fbarrat@linux.vnet.ibm.com
Subject: Re: [PATCH] ocxl: Mmio invalidation support
Date: Tue, 17 Nov 2020 11:41:17 +1100 [thread overview]
Message-ID: <76002af5-6ada-ad2c-0470-e2cdc5b360c2@linux.ibm.com> (raw)
In-Reply-To: <20201113153333.290505-1-clombard@linux.vnet.ibm.com>
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@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@linux.ibm.com IBM Australia Limited
prev parent reply other threads:[~2020-11-17 0:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-13 15:33 [PATCH] ocxl: Mmio invalidation support Christophe Lombard
2020-11-16 17:51 ` Frederic Barrat
2020-11-17 0:41 ` Andrew Donnellan [this message]
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