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

[Xiang W]

在 2022-01-04星期二的 15:43 +0530，Anup Patel写道：
> 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>
The interrupts triggered by AIA should all be external interrupts. For
platforms that support AIA, mcause should only receive external
interrupts, and then handle timers and software interrupts in external
interrupts. We shouldn't need two versions of sbi_trap_irq

Regards,
Xiang W
> ---
>  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
> 
>