[PATCH v2] lib: sbi: Fix mhpmeventh access for rv32 in absence of sscofpmf

[Anup Patel]

On Fri, Apr 29, 2022 at 12:18 AM Atish Patra <atishp at rivosinc.com> wrote:
>
> MHPMEVENT3H-31H are defined in sscofpmf extension. Thus, they should be
> accessed only if sscofpmf is present.
>
> Signed-off-by: Atish Patra <atishp at rivosinc.com>

Looks good to me.

Reviewed-by: Anup Patel <anup at brainfault.org>

Regards,
Anup

> ---
> Changes from v1->V2:
> 1. Fixed the compilation error in rv64
> ---
>  lib/sbi/riscv_asm.c | 4 ++++
>  lib/sbi/sbi_pmu.c   | 8 ++++++--
>  2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/lib/sbi/riscv_asm.c b/lib/sbi/riscv_asm.c
> index 5eab1ed5724f..ddc4c139b95e 100644
> --- a/lib/sbi/riscv_asm.c
> +++ b/lib/sbi/riscv_asm.c
> @@ -139,6 +139,10 @@ unsigned long csr_read_num(int csr_num)
>         switchcase_csr_read_4(CSR_MHPMCOUNTER4H, ret)
>         switchcase_csr_read_8(CSR_MHPMCOUNTER8H, ret)
>         switchcase_csr_read_16(CSR_MHPMCOUNTER16H, ret)
> +       /**
> +        * The CSR range MHPMEVENT[3-16]H are available only if sscofpmf
> +        * extension is present. The caller must ensure that.
> +        */
>         switchcase_csr_read(CSR_MHPMEVENT3H, ret)
>         switchcase_csr_read_4(CSR_MHPMEVENT4H, ret)
>         switchcase_csr_read_8(CSR_MHPMEVENT8H, ret)
> diff --git a/lib/sbi/sbi_pmu.c b/lib/sbi/sbi_pmu.c
> index 7ea0ca5e2fa7..f458c6d4a221 100644
> --- a/lib/sbi/sbi_pmu.c
> +++ b/lib/sbi/sbi_pmu.c
> @@ -404,7 +404,9 @@ static int pmu_reset_hw_mhpmevent(int ctr_idx)
>                 return SBI_EFAIL;
>  #if __riscv_xlen == 32
>         csr_write_num(CSR_MHPMEVENT3 + ctr_idx - 3, 0);
> -       csr_write_num(CSR_MHPMEVENT3H + ctr_idx - 3, 0);
> +       if (sbi_hart_has_feature(sbi_scratch_thishart_ptr(),
> +                                 SBI_HART_HAS_SSCOFPMF))
> +               csr_write_num(CSR_MHPMEVENT3H + ctr_idx - 3, 0);
>  #else
>         csr_write_num(CSR_MHPMEVENT3 + ctr_idx - 3, 0);
>  #endif
> @@ -483,7 +485,9 @@ static int pmu_update_hw_mhpmevent(struct sbi_pmu_hw_event *hw_evt, int ctr_idx,
>
>  #if __riscv_xlen == 32
>         csr_write_num(CSR_MHPMEVENT3 + ctr_idx - 3, mhpmevent_val & 0xFFFFFFFF);
> -       csr_write_num(CSR_MHPMEVENT3H + ctr_idx - 3, mhpmevent_val >> BITS_PER_LONG);
> +       if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> +               csr_write_num(CSR_MHPMEVENT3H + ctr_idx - 3,
> +                             mhpmevent_val >> BITS_PER_LONG);
>  #else
>         csr_write_num(CSR_MHPMEVENT3 + ctr_idx - 3, mhpmevent_val);
>  #endif
> --
> 2.25.1
>