From 299824e68bd0fac60f8352c940fd731fde609de1 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Tue, 23 Aug 2022 19:33:19 +0100 Subject: [PATCH] dt-bindings: riscv: add new riscv,isa strings for emulators The QEMU virt and spike machines currently export a riscv,isa string of "rv64imafdcsuh", While the RISC-V foundation has been ratifying a bunch of extenstions etc, the kernel has remained relatively static with what hardware is supported - but the same is not true of QEMU. Using the virt machine and running dt-validate on the dumped dtb fails, partly due to the unexpected isa string. Rather than enumerate the many many possbilities, change the pattern to a regex, with the following assumptions: - ima are required - the single letter order is fixed & we don't care about things that can't even do "ima" - the standard multi letter extensions are all in a "_z" format where the first letter of is a valid single letter extension - _s & _h are used for supervisor and hyper visor extensions - convention says that after the first two chars, a standard multi letter extension name could be an english word (ifencei anyone?) so it's not worth restricting the charset - as the above is just convention, don't apply any charset restrictions to reduce future churn - vendor ISA extensions begind with _x and have no charset restrictions - we don't care about an e extension from an OS pov - that attempting to validate the contents of the multiletter extensions with dt-validate beyond the formatting is a futile, massively verbose or unwieldy exercise at best The following limitations also apply: - multi letter extension ordering is not enforced. dt-schema does not appear to allow for named match groups, so the resulting regex would be even more of a headache - ditto for the numbered extensions Finally, add me as a maintainer of the binding so that when it breaks in the future, I can be held responsible! Reported-by: Rob Herring Link: https://lore.kernel.org/linux-riscv/20220803170552.GA2250266-robh@kernel.org/ Reviewed-by: Andrew Jones Acked-by: Guo Ren Signed-off-by: Conor Dooley Acked-by: Heiko Stuebner Reviewed-by: Rob Herring Link: https://lore.kernel.org/r/20220823183319.3314940-4-mail@conchuod.ie Signed-off-by: Palmer Dabbelt --- Documentation/devicetree/bindings/riscv/cpus.yaml | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml index 873dd12f6e89..90a7cabf58fe 100644 --- a/Documentation/devicetree/bindings/riscv/cpus.yaml +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml @@ -9,6 +9,7 @@ title: RISC-V bindings for 'cpus' DT nodes maintainers: - Paul Walmsley - Palmer Dabbelt + - Conor Dooley description: | This document uses some terminology common to the RISC-V community @@ -79,9 +80,7 @@ properties: insensitive, letters in the riscv,isa string must be all lowercase to simplify parsing. $ref: "/schemas/types.yaml#/definitions/string" - enum: - - rv64imac - - rv64imafdc + pattern: ^rv(?:64|32)imaf?d?q?c?b?v?k?h?(?:_[hsxz](?:[a-z])+)*$ # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here timebase-frequency: false