Re: [PATCH v2 07/11] arm64: mops: handle MOPS exceptions

From: Catalin Marinas
Date: Mon Jun 05 2023 - 08:05:10 EST


On Mon, Jun 05, 2023 at 07:43:27PM +0800, Shaoqin Huang wrote:
> Hi Kristina,
>
> On 5/9/23 22:22, Kristina Martsenko wrote:
> > The memory copy/set instructions added as part of FEAT_MOPS can take an
> > exception (e.g. page fault) part-way through their execution and resume
> > execution afterwards.
> >
> > If however the task is re-scheduled and execution resumes on a different
> > CPU, then the CPU may take a new type of exception to indicate this.
> > This is because the architecture allows two options (Option A and Option
> > B) to implement the instructions and a heterogeneous system can have
> > different implementations between CPUs.
> >
> > In this case the OS has to reset the registers and restart execution
> > from the prologue instruction. The algorithm for doing this is provided
> > as part of the Arm ARM.
>
> What is the Arm ARM? I'm not quite understand it.

The Arm Architecture Reference Manual:

https://developer.arm.com/documentation/ddi0487/latest

(the acronym we pretty well known among the arm/arm64 developers)

--
Catalin