Kernel/Interrupts: Enumerate nested handlers in a shared handler

When asked to enumerate all interrupt handlers, display all shared
handlers within it instead of just returning the responsible handler of
them.

Kernel/Interrupts/InterruptManagement.cpp

@@ -13,6 +13,7 @@
 #include <Kernel/Interrupts/IOAPIC.h>
 #include <Kernel/Interrupts/InterruptManagement.h>
 #include <Kernel/Interrupts/PIC.h>
+#include <Kernel/Interrupts/SharedIRQHandler.h>
 #include <Kernel/Interrupts/SpuriousInterruptHandler.h>
 #include <Kernel/Interrupts/UnhandledInterruptHandler.h>
 #include <Kernel/VM/TypedMapping.h>
@@ -49,6 +50,10 @@ void InterruptManagement::enumerate_interrupt_handlers(Function<void(GenericInte
 {
     for (int i = 0; i < GENERIC_INTERRUPT_HANDLERS_COUNT; i++) {
         auto& handler = get_interrupt_handler(i);
+        if (handler.type() == HandlerType::SharedIRQHandler) {
+            static_cast<SharedIRQHandler&>(handler).enumerate_handlers(callback);
+            continue;
+        }
         if (handler.type() != HandlerType::UnhandledInterruptHandler)
             callback(handler);
     }

Kernel/Interrupts/SharedIRQHandler.cpp

@@ -42,6 +42,14 @@ bool SharedIRQHandler::eoi()
     return true;
 }
 
+void SharedIRQHandler::enumerate_handlers(Function<void(GenericInterruptHandler&)>& callback)
+{
+    for (auto* handler : m_handlers) {
+        VERIFY(handler);
+        callback(*handler);
+    }
+}
+
 SharedIRQHandler::SharedIRQHandler(u8 irq)
     : GenericInterruptHandler(irq)
     , m_responsible_irq_controller(InterruptManagement::the().get_responsible_irq_controller(irq))

Kernel/Interrupts/SharedIRQHandler.h

@@ -26,6 +26,8 @@ public:
 
     virtual bool eoi() override;
 
+    void enumerate_handlers(Function<void(GenericInterruptHandler&)>&);
+
     virtual size_t sharing_devices_count() const override { return m_handlers.size(); }
     virtual bool is_shared_handler() const override { return true; }
     virtual bool is_sharing_with_others() const override { return false; }