Re: [PATCH v7 05/16] target/riscv/tcg: add 'zic64b' support

[Andrew Jones]

On Tue, Oct 31, 2023 at 05:39:05PM -0300, Daniel Henrique Barboza wrote:
> zic64b is defined in the RVA22U64 profile [1] as a named feature for
> "Cache blocks must be 64 bytes in size, naturally aligned in the address
> space". It's a fantasy name for 64 bytes cache blocks. The RVA22U64
> profile mandates this feature, meaning that applications using this
> profile expects 64 bytes cache blocks.
> 
> To make the upcoming RVA22U64 implementation complete, we'll zic64b as
> a 'named feature', not a regular extension. This means that:
> 
> - it won't be exposed to users;
> - it won't be written in riscv,isa.
> 
> This will be extended to other named extensions in the future, so we're
> creating some common boilerplate for them as well.
> 
> zic64b is default to 'true' since we're already using 64 bytes blocks.
> If any cache block size (cbo{m,p,z}_blocksize) is changed to something
> different than 64, zic64b is set to 'false'.
> 
> Our profile implementation will then be able to check the current state
> of zic64b and take the appropriate action (e.g. throw a warning).
> 
> [1] 
> https://github.com/riscv/riscv-profiles/releases/download/v1.0/profiles.pdf
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  target/riscv/cpu.c         |  6 ++++++
>  target/riscv/cpu.h         |  1 +
>  target/riscv/cpu_cfg.h     |  1 +
>  target/riscv/tcg/tcg-cpu.c | 14 ++++++++++++++
>  4 files changed, 22 insertions(+)
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>