Kernel: Introduce PCIIRQHandler

PCIIRQHandler is a generic IRQ handler that the device driver can
inherit to use either Pin or MSI(x) based interrupt mechanism.

The PCIIRQHandler can do what the existing IRQHandler can do for pin
based interrupts but also deal with MSI based interrupts. We can
hopefully convert all the PCI based devices to use this handler so that
MSI(x) can be used.

Kernel/Interrupts/PCIIRQHandler.cpp

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2023, Pankaj R <dev@pankajraghav.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Arch/InterruptManagement.h>
+#include <Kernel/Arch/PCIMSI.h>
+#include <Kernel/Debug.h>
+#include <Kernel/Interrupts/PCIIRQHandler.h>
+
+namespace Kernel {
+
+PCIIRQHandler::PCIIRQHandler(PCI::Device& device, u8 irq)
+    : GenericInterruptHandler(irq)
+    , device(device)
+{
+    auto type = device.get_interrupt_type();
+
+    if (type == PCI::InterruptType::PIN)
+        m_responsible_irq_controller = InterruptManagement::the().get_responsible_irq_controller(irq);
+
+    if (is_registered())
+        disable_irq();
+}
+
+bool PCIIRQHandler::eoi()
+{
+    dbgln_if(IRQ_DEBUG, "EOI IRQ {}", interrupt_number());
+    if (m_shared_with_others)
+        return false;
+    if (!m_responsible_irq_controller.is_null())
+        m_responsible_irq_controller->eoi(*this);
+    else
+        msi_signal_eoi();
+    return true;
+}
+
+void PCIIRQHandler::enable_irq()
+{
+    dbgln_if(IRQ_DEBUG, "Enable IRQ {}", interrupt_number());
+    if (!is_registered())
+        register_interrupt_handler();
+    m_enabled = true;
+    if (m_shared_with_others)
+        return;
+    if (!m_responsible_irq_controller.is_null())
+        m_responsible_irq_controller->enable(*this);
+    else
+        device.enable_interrupt(interrupt_number());
+}
+
+void PCIIRQHandler::disable_irq()
+{
+    dbgln_if(IRQ_DEBUG, "Disable IRQ {}", interrupt_number());
+    m_enabled = false;
+
+    if (m_shared_with_others)
+        return;
+    if (!m_responsible_irq_controller.is_null())
+        m_responsible_irq_controller->disable(*this);
+    else
+        device.disable_interrupt(interrupt_number());
+}
+
+}