[RFC PATCH 0/2] Introduce INTC and VIRQ layer prototypes

[Raymond Mao]

From: Raymond Mao <raymond.mao at riscstar.com>

This RFC introduces INTC and VIRQ layers for APLIC wired interrupt
support in OpenSBI.

In the current OpenSBI implementation, APLIC support primarily focuses
on initialization and delegation, while external interrupt handling
for wired interrupts remains largely stubbed. As a result:
- There is no generic mechanism for OpenSBI drivers or platforms to
  register handlers for wired interrupt lines.
- Interrupt dispatch remains tightly coupled to specific irqchip
  implementations.

The goal is to introduce a small, extensible abstraction INTC
(Interrupt Controller) layer to hide the HW details and provide
abstract operations like interrupt provider registration,
claim/complete/mask/unmask operations with IRQ number mapping to avoid
exposure of hwirq.

VIRQ (Virtual IRQ) layer is on top of INTC, providing IRQ state
management via per-(domain,hart) IRQ pending queue, with courier
dispatching and interface to enqueue/pop/complete an IRQ.

Raymond Mao (2):
  lib: sbi: introduce INTC abstraction for wired interrupts
  lib: sbi: Add VIRQ layer

 sbi_intc.h | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 sbi_virq.h | 71 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 170 insertions(+)
 create mode 100644 sbi_intc.h
 create mode 100644 sbi_virq.h

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2.25.1