[PATCH v2 1/2] lib: sbi: introduce abstraction for wired interrupt handling

[Raymond Mao]

Hi Anup,

On Sat, Feb 7, 2026 at 5:10 AM Anup Patel <anup at brainfault.org> wrote:
>
> On Mon, Feb 2, 2026 at 8:32 PM Raymond Mao <raymondmaoca at gmail.com> wrote:
> >
> > From: Raymond Mao <raymond.mao at riscstar.com>
> >
> > Add wired interrupt handling abstraction into irqchip.
> > This introduces a small provider interface based on
> > claim/complete/mask/unmak semantics, allowing to register a wired
> > interrupt controller as a provider.
> >
> > Signed-off-by: Raymond Mao <raymond.mao at riscstar.com>
> > ---
> >  include/sbi/sbi_irqchip.h | 52 +++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 52 insertions(+)
> >
> > diff --git a/include/sbi/sbi_irqchip.h b/include/sbi/sbi_irqchip.h
> > index e0ae12f5..27b88765 100644
> > --- a/include/sbi/sbi_irqchip.h
> > +++ b/include/sbi/sbi_irqchip.h
> > @@ -27,6 +27,38 @@ struct sbi_irqchip_device {
> >         int (*irq_handle)(void);
> >  };
> >
> > +/* Handler for a specified hwirq */
> > +typedef int (*sbi_irqchip_irq_handler_t)(void *priv);
> > +
> > +/* Provider operations */
> > +struct sbi_irqchip_provider_ops {
> > +       /*
> > +        * Claim a pending wired interrupt on current hart.
> > +        * Returns:
> > +        *   SBI_OK      : *hwirq is valid
> > +        *   SBI_ENOENT  : no pending wired interrupt
> > +        *   <0          : error
> > +        */
> > +       int (*claim)(void *ctx, u32 *hwirq);
> > +
> > +       /*
> > +        * Complete/acknowledge a previously claimed wired interrupt
> > +        * (if required by HW).
> > +        * Some HW may not require an explicit completion.
> > +        */
> > +       void (*complete)(void *ctx, u32 hwirq);
> > +
> > +       /*
> > +        * mask/unmask a wired interrupt line.
> > +        *
> > +        * These are required for reliable couriering of level-triggered device
> > +        * interrupts to S-mode: mask in M-mode before enqueueing, and unmask
> > +        * after S-mode has cleared the device interrupt source.
> > +        */
> > +       void (*mask)(void *ctx, u32 hwirq);
> > +       void (*unmask)(void *ctx, u32 hwirq);
> > +};
> > +
> >  /**
> >   * Process external interrupts
> >   *
> > @@ -46,4 +78,24 @@ int sbi_irqchip_init(struct sbi_scratch *scratch, bool cold_boot);
> >  /** Exit interrupt controllers */
> >  void sbi_irqchip_exit(struct sbi_scratch *scratch);
> >
> > +/*
> > + * Register the active wired interrupt provider.
> > + * - max_hwirq specifies the highest valid hwirq ID.
> > + */
> > +int sbi_irqchip_register_provider(const struct sbi_irqchip_provider_ops *ops,
> > +                                 void *ctx, u32 max_hwirq);
> > +
> > +u32 sbi_irqchip_get_max_src(void);
> > +
> > +/* Set/clear handler for a specified hwirq */
> > +int sbi_irqchip_set_handler(u32 hwirq, sbi_irqchip_irq_handler_t handler,
> > +                           void *priv);
> > +int sbi_irqchip_clear_handler(u32 hwirq);
> > +
> > +void sbi_irqchip_mask_irq(u32 hwirq);
> > +void sbi_irqchip_unmask_irq(u32 hwirq);
> > +
> > +/* external interrupt handler (irqchip device hook) */
> > +int sbi_irqchip_handle_external_irq(void);
> > +
>
> I did not mean renaming and moving stuff to sbi_irqchip.h
> instead, my expectation was to use struct sbi_irqchip_device
> as the abstraction for the interrupt controller.
>

I can wrap sbi_irqchip_provider_ops into sbi_irqchip_device if that
looks better.
It is not a big change to the implementation itself.

Regards,
Raymond

> Regards,
> Anup