Re: [PATCH v2 1/2] target/riscv: Add Zaamo and Zalrsc extensions

[Alistair Francis <alistair23@gmail.com>]

On Fri, Jan 19, 2024 at 9:22 PM Rob Bradford <rbradford@rivosinc.com> wrote:
>
> These extensions represent the atomic operations from A (Zaamo) and the
> Load-Reserved/Store-Conditional operations from A (Zalrsc)
>
> Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  target/riscv/cpu.c     | 5 +++++
>  target/riscv/cpu_cfg.h | 2 ++
>  2 files changed, 7 insertions(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 8d3ec74a1c..604baf53c8 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -103,7 +103,9 @@ const RISCVIsaExtData isa_edata_arr[] = {
>      ISA_EXT_DATA_ENTRY(zihintpause, PRIV_VERSION_1_10_0, ext_zihintpause),
>      ISA_EXT_DATA_ENTRY(zihpm, PRIV_VERSION_1_12_0, ext_zihpm),
>      ISA_EXT_DATA_ENTRY(zmmul, PRIV_VERSION_1_12_0, ext_zmmul),
> +    ISA_EXT_DATA_ENTRY(zaamo, PRIV_VERSION_1_12_0, ext_zaamo),
>      ISA_EXT_DATA_ENTRY(zacas, PRIV_VERSION_1_12_0, ext_zacas),
> +    ISA_EXT_DATA_ENTRY(zalrsc, PRIV_VERSION_1_12_0, ext_zalrsc),
>      ISA_EXT_DATA_ENTRY(zawrs, PRIV_VERSION_1_12_0, ext_zawrs),
>      ISA_EXT_DATA_ENTRY(zfa, PRIV_VERSION_1_12_0, ext_zfa),
>      ISA_EXT_DATA_ENTRY(zfbfmin, PRIV_VERSION_1_12_0, ext_zfbfmin),
> @@ -1491,6 +1493,9 @@ const RISCVCPUMultiExtConfig riscv_cpu_experimental_exts[] = {
>      MULTI_EXT_CFG_BOOL("x-smaia", ext_smaia, false),
>      MULTI_EXT_CFG_BOOL("x-ssaia", ext_ssaia, false),
>
> +    MULTI_EXT_CFG_BOOL("x-zaamo", ext_zaamo, false),
> +    MULTI_EXT_CFG_BOOL("x-zalrsc", ext_zalrsc, false),

We should implement the extension before we expose it to userspace.
That helps maintain bisectability of the code

Alistair

> +
>      MULTI_EXT_CFG_BOOL("x-zvfh", ext_zvfh, false),
>      MULTI_EXT_CFG_BOOL("x-zvfhmin", ext_zvfhmin, false),
>
> diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h
> index fea14c275f..cc4c30244c 100644
> --- a/target/riscv/cpu_cfg.h
> +++ b/target/riscv/cpu_cfg.h
> @@ -78,7 +78,9 @@ struct RISCVCPUConfig {
>      bool ext_svnapot;
>      bool ext_svpbmt;
>      bool ext_zdinx;
> +    bool ext_zaamo;
>      bool ext_zacas;
> +    bool ext_zalrsc;
>      bool ext_zawrs;
>      bool ext_zfa;
>      bool ext_zfbfmin;
> --
> 2.43.0
>
>