[PATCH v2 03/13] lib: sbi: Use AIA CSRs for local interrupts when available

[Atish Patra]

On Wed, Feb 9, 2022 at 7:05 AM Anup Patel <apatel at ventanamicro.com> wrote:
>
> We should use AIA CSRs to process local interrupts whenever AIA
> is available.
>
> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
>  lib/sbi/sbi_trap.c | 57 +++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 46 insertions(+), 11 deletions(-)
>
> diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c
> index 8d20e04..bc8961f 100644
> --- a/lib/sbi/sbi_trap.c
> +++ b/lib/sbi/sbi_trap.c
> @@ -195,6 +195,44 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
>         return 0;
>  }
>
> +static int sbi_trap_nonaia_irq(struct sbi_trap_regs *regs, ulong mcause)
> +{
> +       mcause &= ~(1UL << (__riscv_xlen - 1));
> +       switch (mcause) {
> +       case IRQ_M_TIMER:
> +               sbi_timer_process();
> +               break;
> +       case IRQ_M_SOFT:
> +               sbi_ipi_process();
> +               break;
> +       default:
> +               return SBI_ENOENT;
> +       };
> +
> +       return 0;
> +}
> +
> +static int sbi_trap_aia_irq(struct sbi_trap_regs *regs, ulong mcause)
> +{
> +       unsigned long mtopi;
> +
> +       while ((mtopi = csr_read(CSR_MTOPI))) {
> +               mtopi = mtopi >> TOPI_IID_SHIFT;
> +               switch (mtopi) {
> +               case IRQ_M_TIMER:
> +                       sbi_timer_process();
> +                       break;
> +               case IRQ_M_SOFT:
> +                       sbi_ipi_process();
> +                       break;
> +               default:
> +                       return SBI_ENOENT;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
>  /**
>   * Handle trap/interrupt
>   *
> @@ -225,18 +263,15 @@ struct sbi_trap_regs *sbi_trap_handler(struct sbi_trap_regs *regs)
>         }
>
>         if (mcause & (1UL << (__riscv_xlen - 1))) {
> -               mcause &= ~(1UL << (__riscv_xlen - 1));
> -               switch (mcause) {
> -               case IRQ_M_TIMER:
> -                       sbi_timer_process();
> -                       break;
> -               case IRQ_M_SOFT:
> -                       sbi_ipi_process();
> -                       break;
> -               default:
> -                       msg = "unhandled external interrupt";
> +               if (sbi_hart_has_feature(sbi_scratch_thishart_ptr(),
> +                                        SBI_HART_HAS_AIA))
> +                       rc = sbi_trap_aia_irq(regs, mcause);
> +               else
> +                       rc = sbi_trap_nonaia_irq(regs, mcause);
> +               if (rc) {
> +                       msg = "unhandled local interrupt";
>                         goto trap_error;
> -               };
> +               }
>                 return regs;
>         }
>
> --
> 2.25.1
>

Reviewed-by: Atish Patra <atishp at rivosinc.com>

-- 
Regards,
Atish