Is there a specification for mnstatus.mpp and mnstatus.mpie?

riscv / riscv-fast-interrupt

Proposal for a RISC-V Core-Local Interrupt Controller (CLIC)

https://jira.riscv.org/browse/RVG-63

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Is there a specification for mnstatus.mpp and mnstatus.mpie? #355

Closed JamesKenneyImperas closed 1 year ago

JamesKenneyImperas commented 1 year ago

Section 4 says:

The mncause.mpp and mncause.mpie fields mirror the mnstatus.mpp and mnstatus.mpie fields, and are aliased into mncause.

The latest RNMI specification I've found (0.4) states that mnstatus has fields MNPP, MNPV and NMIE only. Is there a more recent version of the RNMI specification describing the fields mentioned here? If so, can you point me at it?

Thanks.

dansmathers commented 1 year ago

I only found this. https://github.com/riscv/riscv-isa-manual/blob/main/src/rnmi.adoc Plan to discuss this question in TG meeting.

kasanovic commented 1 year ago

RNMI spec has been stalled waiting ACT and SAIL resources. We are trying to unblock the RNMI spec now.

kasanovic commented 1 year ago

There should actually be no interaction between resumable NMI (RNMI) and the fast interrupts section, and the sections regarding NMI (both non-resumable and resumable) will be re-written. The RNMI CSRs are separate from the fast interrupts CSRs and so the state does not need to be saved in the RNMI registers. This makes the design of the RNMI extension orthogonal to the core's general interrupt scheme.

kasanovic commented 1 year ago

closed with #365