[PATCH v2 04/13] lib: sbi: Add sbi_trap_set_external_irqfn() API

[Anup Patel]

On Wed, Feb 9, 2022 at 8:35 PM Anup Patel <apatel at ventanamicro.com> wrote:
>
> This patch adds sbi_trap_set_external_irqfn() API which can be used by
> OpenSBI platform code to set a callback function for external interrupts.
> The RISC-V AIA IMSIC driver will use this API to implement inter-processor
> interrupts on-top-of MSIs.
>
> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> Reviewed-by: Atish Patra <atishp at rivosinc.com>

Applied this patch to the riscv/opensbi repo.

Regards,
Anup

> ---
>  include/sbi/sbi_trap.h |  2 ++
>  lib/sbi/sbi_trap.c     | 29 +++++++++++++++++++++++++++++
>  2 files changed, 31 insertions(+)
>
> diff --git a/include/sbi/sbi_trap.h b/include/sbi/sbi_trap.h
> index d205056..4f611fa 100644
> --- a/include/sbi/sbi_trap.h
> +++ b/include/sbi/sbi_trap.h
> @@ -205,6 +205,8 @@ struct sbi_trap_info {
>  int sbi_trap_redirect(struct sbi_trap_regs *regs,
>                       struct sbi_trap_info *trap);
>
> +void sbi_trap_set_external_irqfn(int (*fn)(struct sbi_trap_regs *regs));
> +
>  struct sbi_trap_regs *sbi_trap_handler(struct sbi_trap_regs *regs);
>
>  void __noreturn sbi_trap_exit(const struct sbi_trap_regs *regs);
> diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c
> index bc8961f..faab90a 100644
> --- a/lib/sbi/sbi_trap.c
> +++ b/lib/sbi/sbi_trap.c
> @@ -195,6 +195,27 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
>         return 0;
>  }
>
> +static int default_irqfn(struct sbi_trap_regs *regs)
> +{
> +       return SBI_ENODEV;
> +}
> +
> +static int (*ext_irqfn)(struct sbi_trap_regs *regs) = default_irqfn;
> +
> +/**
> + * Set external irq handler function
> + *
> + * This function is called by OpenSBI platform code to set a handler for
> + * external interrupts
> + *
> + * @param fn function pointer for handling external irqs
> + */
> +void sbi_trap_set_external_irqfn(int (*fn)(struct sbi_trap_regs *regs))
> +{
> +       if (fn)
> +               ext_irqfn = fn;
> +}
> +
>  static int sbi_trap_nonaia_irq(struct sbi_trap_regs *regs, ulong mcause)
>  {
>         mcause &= ~(1UL << (__riscv_xlen - 1));
> @@ -205,6 +226,8 @@ static int sbi_trap_nonaia_irq(struct sbi_trap_regs *regs, ulong mcause)
>         case IRQ_M_SOFT:
>                 sbi_ipi_process();
>                 break;
> +       case IRQ_M_EXT:
> +               return ext_irqfn(regs);
>         default:
>                 return SBI_ENOENT;
>         };
> @@ -214,6 +237,7 @@ static int sbi_trap_nonaia_irq(struct sbi_trap_regs *regs, ulong mcause)
>
>  static int sbi_trap_aia_irq(struct sbi_trap_regs *regs, ulong mcause)
>  {
> +       int rc;
>         unsigned long mtopi;
>
>         while ((mtopi = csr_read(CSR_MTOPI))) {
> @@ -225,6 +249,11 @@ static int sbi_trap_aia_irq(struct sbi_trap_regs *regs, ulong mcause)
>                 case IRQ_M_SOFT:
>                         sbi_ipi_process();
>                         break;
> +               case IRQ_M_EXT:
> +                       rc = ext_irqfn(regs);
> +                       if (rc)
> +                               return rc;
> +                       break;
>                 default:
>                         return SBI_ENOENT;
>                 }
> --
> 2.25.1
>