Re: [PATCH 2/5] target/riscv: Update VS timer whenever htimedelta changes

[Alistair Francis <alistair23@gmail.com>]

On Fri, Oct 28, 2022 at 2:52 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> The htimedelta[h] CSR has impact on the VS timer comparison so we
> should call riscv_timer_write_timecmp() whenever htimedelta changes.
>
> Fixes: 3ec0fe18a31f ("target/riscv: Add vstimecmp suppor")
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/riscv/csr.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 716f9d960e..4b1a608260 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -2722,6 +2722,8 @@ static RISCVException read_htimedelta(CPURISCVState *env, int csrno,
>  static RISCVException write_htimedelta(CPURISCVState *env, int csrno,
>                                         target_ulong val)
>  {
> +    RISCVCPU *cpu = env_archcpu(env);
> +
>      if (!env->rdtime_fn) {
>          return RISCV_EXCP_ILLEGAL_INST;
>      }
> @@ -2731,6 +2733,12 @@ static RISCVException write_htimedelta(CPURISCVState *env, int csrno,
>      } else {
>          env->htimedelta = val;
>      }
> +
> +    if (cpu->cfg.ext_sstc && env->rdtime_fn) {
> +        riscv_timer_write_timecmp(cpu, env->vstimer, env->vstimecmp,
> +                                  env->htimedelta, MIP_VSTIP);
> +    }
> +
>      return RISCV_EXCP_NONE;
>  }
>
> @@ -2748,11 +2756,19 @@ static RISCVException read_htimedeltah(CPURISCVState *env, int csrno,
>  static RISCVException write_htimedeltah(CPURISCVState *env, int csrno,
>                                          target_ulong val)
>  {
> +    RISCVCPU *cpu = env_archcpu(env);
> +
>      if (!env->rdtime_fn) {
>          return RISCV_EXCP_ILLEGAL_INST;
>      }
>
>      env->htimedelta = deposit64(env->htimedelta, 32, 32, (uint64_t)val);
> +
> +    if (cpu->cfg.ext_sstc && env->rdtime_fn) {
> +        riscv_timer_write_timecmp(cpu, env->vstimer, env->vstimecmp,
> +                                  env->htimedelta, MIP_VSTIP);
> +    }
> +
>      return RISCV_EXCP_NONE;
>  }
>
> --
> 2.34.1
>
>