Re: [RFC PATCH v2 1/4] target/riscv: smstateen check for fcsr

[Mayuresh Chitale]

On Sat, Apr 15, 2023 at 6:32 AM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
>
> On 2023/4/15 00:01, Mayuresh Chitale wrote:
> > If smstateen is implemented and smtateen0.fcsr is clear and misa.F
> > is off then the floating point operations must return illegal
> > instruction exception or virtual instruction trap, if relevant.
> >
> > Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
> > ---
> >   target/riscv/csr.c | 23 +++++++++++++++++++++++
> >   1 file changed, 23 insertions(+)
> >
> > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> > index f4d2dcfdc8..8ae9e95f9f 100644
> > --- a/target/riscv/csr.c
> > +++ b/target/riscv/csr.c
> > @@ -82,6 +82,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
> >           !riscv_cpu_cfg(env)->ext_zfinx) {
> >           return RISCV_EXCP_ILLEGAL_INST;
> >       }
> > +
> > +    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
> > +        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
> > +    }
> >   #endif
> >       return RISCV_EXCP_NONE;
> >   }
> > @@ -2081,6 +2085,9 @@ static RISCVException write_mstateen0(CPURISCVState 
> > *env, int csrno,
> >                                         target_ulong new_val)
> >   {
> >       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> > +    if (!riscv_has_ext(env, RVF)) {
> > +        wr_mask |= SMSTATEEN0_FCSR;
> > +    }
> >
> >       return write_mstateen(env, csrno, wr_mask, new_val);
> >   }
> > @@ -2117,6 +2124,10 @@ static RISCVException write_mstateen0h(CPURISCVState 
> > *env, int csrno,
> >   {
> >       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >
> > +    if (!riscv_has_ext(env, RVF)) {
> > +        wr_mask |= SMSTATEEN0_FCSR;
> > +    }
> > +
>
> FCSR is bit 1 of mstateen0.  So it seems unnecessary to be added to
> wr_mask for mstateen0h.
>
> Similar to hstateen0h.
>
> Otherwise,  Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
>
Thanks, I will make the change above in the next version.
> Weiwei Li
> >       return write_mstateenh(env, csrno, wr_mask, new_val);
> >   }
> >
> > @@ -2154,6 +2165,10 @@ static RISCVException write_hstateen0(CPURISCVState 
> > *env, int csrno,
> >   {
> >       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >
> > +    if (!riscv_has_ext(env, RVF)) {
> > +        wr_mask |= SMSTATEEN0_FCSR;
> > +    }
> > +
> >       return write_hstateen(env, csrno, wr_mask, new_val);
> >   }
> >
> > @@ -2193,6 +2208,10 @@ static RISCVException write_hstateen0h(CPURISCVState 
> > *env, int csrno,
> >   {
> >       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >
> > +    if (!riscv_has_ext(env, RVF)) {
> > +        wr_mask |= SMSTATEEN0_FCSR;
> > +    }
> > +
> >       return write_hstateenh(env, csrno, wr_mask, new_val);
> >   }
> >
> > @@ -2240,6 +2259,10 @@ static RISCVException write_sstateen0(CPURISCVState 
> > *env, int csrno,
> >   {
> >       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >
> > +    if (!riscv_has_ext(env, RVF)) {
> > +        wr_mask |= SMSTATEEN0_FCSR;
> > +    }
> > +
> >       return write_sstateen(env, csrno, wr_mask, new_val);
> >   }
> >
>