Re: [PATCH] openrisc: Define memory barrier mb

From: Peter Zijlstra
Date: Sat May 15 2021 - 08:59:19 EST


On Sat, May 15, 2021 at 04:58:08PM +0900, Stafford Horne wrote:
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>
> This came up in the discussion of the requirements of qspinlock on an
> architecture. OpenRISC uses qspinlock, but it was noticed that the
> memmory barrier was not defined.
>
> Peter defined it in the mail thread writing:
>
> As near as I can tell this should do. The arch spec only lists
> this one instruction and the text makes it sound like a completion
> barrier.
>
> This is correct so applying this patch.
>
> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> [shorne@xxxxxxxxx:Turned the mail into a patch]
> Signed-off-by: Stafford Horne <shorne@xxxxxxxxx>
> ---
> I just applied the patch posted by Peter in the mail as is hence it is labeled
> from peter. This also required me to set the Signed-off-by to Peter.
>
> If there is any issue with that let me know. I tested this out on my single
> processor setup and it all works fine, it will take me some time to get my SMP
> setup up and running again to test the other patches, but I figured I would send
> this patch first.

Works for me; thanks for not loosing it ;-)

> Also, I got delayed because I had to rebuild my main workstation after a
> hardware failure.

*ouch*, hate it when that happens.