[PATCH v5 00/17] ARM Error Source Table V2 Support

[Borislav Petkov]

On Mon, Jan 05, 2026 at 05:12:25PM +0800, Ruidong Tian wrote:
> > What is a "RAS node"?
> A RAS node is the hardware interface for error reporting and control,
> consisting of one or more register sets (a collection of RAS records). It is
> responsible for error logging and interrupt signaling[0].

OMG, one more meaning for the word "node". Because we're not ambiguous enough.

/facepalm

> A single hardware component can feature multiple RAS nodes. For example, a
> memory controller is treated as a "RAS device", where each memory channel
> has its own RAS node. Interrupts generated by these nodes are typically
> aggregated into a single interrupt line managed at the RAS device level.

Nomenclaturial tragedy, I'd say.

> Comparison with x86 MCA:
> 
> RAS record ≈ MCA bank.
> RAS node ≈ A set of MCA banks + CMCI on a core.
> 
> The key difference lies in uncore handling: x86 typically maps uncore errors
> (like those from a memory controller) into core-based MCA banks. In
> contrast, ARM requires uncore components to provide their own standalone RAS
> nodes. When a component requires multiple such nodes, they are grouped and
> managed as a "RAS device" in AEST driver.
> 
> [0]: https://developer.arm.com/documentation/ihi0100/latest

Yah, thanks for explaining.

> > The ATL is very AMD-specific. What does "conceptually similar" mean exactly?
> By "conceptually similar," I mean that both ARM and AMD share the same
> functional requirement: translating between a System Physical Address (SPA)
> and a device-specific address (like a DRAM address) for RAS purposes.
> 
> The goal here is not to share the hardware-specific translation logic, but
> to provide a unified interface (an abstraction layer). The actual
> implementation of the translation remains entirely architecture-specific.

And why do we need an arch-overlapping unified interface?

You can just as well have aest_convert_la_to_spa() and none of that "unifying"
churn.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette