Re: [PATCH v2 01/14] Documentation: PCI: Add specification for the *PCI NTB* function device

Kishon Vijay Abraham I
2020-06-12T05:31:29Z

Hi Matthew,

On 6/11/2020 8:43 PM, Matthew Wilcox wrote:
> On Thu, Jun 11, 2020 at 06:35:12PM +0530, Kishon Vijay Abraham I wrote:
>> +++ b/Documentation/PCI/endpoint/pci-ntb-function.rst
>> @@ -0,0 +1,344 @@
>> +.. SPDX-License-Identifier: GPL-2.0
>> +
>> +=================
>> +PCI NTB Function
>> +=================
>> +
>> +:Author: Kishon Vijay Abraham I <kishon@ti.com>
>> +
>> +PCI NTB Function allows two different systems (or hosts) to communicate
>> +with each other by configurig the endpoint instances in such a way that
>> +transactions from one system is routed to the other system.
>
> At no point in this document do you expand "NTB" into Non-Transparent
> Bridge. The above paragraph probably also needs to say something like "By
> making each host appear as a device to the other host". Although maybe
> that's not entirely accurate? It's been a few years since I last played
> with NTBs.
>
> So how about the following opening paragraph:
>
> PCI Non Transparent Bridges (NTB) allow two host systems to communicate
> with each other by exposing each host as a device to the other host.
> NTBs typically support the ability to generate interrupts on the remote
> machine, expose memory ranges as BARs and perform DMA. They also support
> scratchpads which are areas of memory within the NTB that are accessible
> from both machines.
>
> ... feel free to fix that up if my memory is out of date or corrupted.

I think that's accurate. I'll wait for review comments on the rest of the
series and I'll fix this one in my next revision.

Thanks
Kishon