Re: [PATCH RESEND 1/6] target/riscv: Introduce extension implied rules definition

[Alistair Francis]

On Wed, Jun 5, 2024 at 4:35 PM <frank.chang@sifive.com> wrote:
>
> From: Frank Chang <frank.chang@sifive.com>
>
> RISCVCPUImpliedExtsRule is created to store the implied rules.
> 'is_misa' flag is used to distinguish whether the rule is derived
> from the MISA or other extensions.
> 'ext' stores the MISA bit if 'is_misa' is true. Otherwise, it stores
> the offset of the extension defined in RISCVCPUConfig. 'ext' will also
> serve as the key of the hash tables to look up the rule in the following
> commit.
>
> Signed-off-by: Frank Chang <frank.chang@sifive.com>
> ---
>  target/riscv/cpu.c |  8 ++++++++
>  target/riscv/cpu.h | 18 ++++++++++++++++++
>  2 files changed, 26 insertions(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index cee6fc4a9a..c7e5cec7ef 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -2242,6 +2242,14 @@ RISCVCPUProfile *riscv_profiles[] = {
>      NULL,
>  };
>
> +RISCVCPUImpliedExtsRule *riscv_misa_implied_rules[] = {
> +    NULL
> +};
> +
> +RISCVCPUImpliedExtsRule *riscv_ext_implied_rules[] = {
> +    NULL
> +};
> +
>  static Property riscv_cpu_properties[] = {
>      DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 1501868008..b5a036cf27 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -122,6 +122,24 @@ typedef enum {
>      EXT_STATUS_DIRTY,
>  } RISCVExtStatus;
>
> +typedef struct riscv_cpu_implied_exts_rule RISCVCPUImpliedExtsRule;
> +
> +struct riscv_cpu_implied_exts_rule {
> +    /* Bitmask indicates the rule enabled status for the harts. */
> +    uint64_t enabled;

I'm not clear why we need this

Alistair

> +    /* True if this is a MISA implied rule. */
> +    bool is_misa;
> +    /* ext is MISA bit if is_misa flag is true, else extension offset. */
> +    const uint32_t ext;
> +    const uint32_t implied_misas;
> +    const uint32_t implied_exts[];
> +};
> +
> +extern RISCVCPUImpliedExtsRule *riscv_misa_implied_rules[];
> +extern RISCVCPUImpliedExtsRule *riscv_ext_implied_rules[];
> +
> +#define RISCV_IMPLIED_EXTS_RULE_END -1
> +
>  #define MMU_USER_IDX 3
>
>  #define MAX_RISCV_PMPS (16)
> --
> 2.43.2
>
>