On Thu, Feb 15, 2018 at 06:55:55PM +0000, James Morse wrote:

Hello!

The aim of this series is to wire arm64's SDEI into APEI.

What's SDEI? Its ARM's "Software Delegated Exception Interface" [0]. It's
used by firmware to tell the OS about firmware-first RAS events.

These Software exceptions can interrupt anything, so I describe them as
NMI-like. They aren't the only NMI-like way to notify the OS about
firmware-first RAS events, the ACPI spec also defines 'NOTFIY_SEA' and
'NOTIFY_SEI'.

(Acronyms: SEA, Synchronous External Abort. The CPU requested some memory,
but the owner of that memory said no. These are always synchronous with the
instruction that caused them. SEI, System-Error Interrupt, commonly called
SError. This is an asynchronous external abort, the memory-owner didn't say no
at the right point. Collectively these things are called external-aborts
How is firmware involved? It traps these and re-injects them into the kernel
once its written the CPER records).

Thank you about those! This is how people should write 0/N introductory
messages with fancy new abbreviations.

:-)

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.