[PATCH v5 1/2] dt-bindings: interrupt-controller: add risc-v,aplic hart indexes

[Rob Herring (Arm)]

On Wed, 29 Jan 2025 11:16:36 +0200, Vladimir Kondratiev wrote:
> Document optional property "riscv,hart-indexes"
> 
> Risc-V APLIC specification defines "hart index" in [1]:
> 
> Within a given interrupt domain, each of the domain’s harts has a
> unique index number in the range 0 to 2^14 − 1 (= 16,383). The index
> number a domain associates with a hart may or may not have any
> relationship to the unique hart identifier (“hart ID”) that the
> RISC-V Privileged Architecture assigns to the hart. Two different
> interrupt domains may employ entirely different index numbers for
> the same set of harts.
> 
> Further, this document says in "4.5 Memory-mapped control
> region for an interrupt domain":
> 
> The array of IDC structures may include some for potential hart index
> numbers that are not actual hart index numbers in the domain. For
> example, the first IDC structure is always for hart index 0, but 0 is
> not necessarily a valid index number for any hart in the domain.
> 
> Support arbitrary hart indexes specified in optional APLIC property
> "riscv,hart-indexes" that should be array of u32 elements, one per
> interrupt target. If this property not specified, fallback is to use
> logical hart indexes within the domain.
> 
> [1]: https://github.com/riscv/riscv-aia
> 
> Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev at mobileye.com>
> Reviewed-by: Anup Patel <anup at brainfault.org>
> ---
>  .../bindings/interrupt-controller/riscv,aplic.yaml        | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 

Reviewed-by: Rob Herring (Arm) <robh at kernel.org>