From 41ebfc91f785c202e8e8f9bd2f67154efad6287e Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Thu, 27 Apr 2023 11:43:42 +0100 Subject: dt-bindings: riscv: explicitly mention assumption of Zicsr & Zifencei support The dt-binding was defined before the extraction of csr access and fence.i into their own extensions, and thus the presence of the I base extension implies Zicsr and Zifencei. There's no harm in adding them obviously, but for backwards compatibility with DTs that existed prior to that extraction, software is unable to differentiate between "i" and "i_zicsr_zifencei" without any further information. Signed-off-by: Conor Dooley Acked-by: Rob Herring Link: https://lore.kernel.org/r/20230427-fence-blurred-c92fb69d4137@wendy Signed-off-by: Palmer Dabbelt --- Documentation/devicetree/bindings/riscv/cpus.yaml | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml index 25d6e8dbffb8..3d2934b15e80 100644 --- a/Documentation/devicetree/bindings/riscv/cpus.yaml +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml @@ -86,6 +86,12 @@ properties: User-Level ISA document, available from https://riscv.org/specifications/ + Due to revisions of the ISA specification, some deviations + have arisen over time. + Notably, riscv,isa was defined prior to the creation of the + Zicsr and Zifencei extensions and thus "i" implies + "zicsr_zifencei". + While the isa strings in ISA specification are case insensitive, letters in the riscv,isa string must be all lowercase to simplify parsing. -- cgit v1.2.3