Kernel: Implement MSI, MSI-X and interrupt reservation

kernel/include/kernel/APIC.h

@@ -14,6 +14,9 @@ namespace Kernel
 		virtual void enable_irq(uint8_t) override;
 		virtual bool is_in_service(uint8_t) override;
 
+		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq) override;
+		virtual BAN::Optional<uint8_t> get_free_irq() override;
+
 	private:
 		uint32_t read_from_local_apic(ptrdiff_t);
 		void write_to_local_apic(ptrdiff_t, uint32_t);
@@ -54,6 +57,7 @@ namespace Kernel
 		Kernel::vaddr_t			m_local_apic_vaddr = 0;
 		BAN::Vector<IOAPIC>		m_io_apics;	
 		uint8_t					m_irq_overrides[0x100] {};
+		uint8_t					m_reserved_gsis[0x100 / 8] {};
 	};
 
 }

kernel/include/kernel/InterruptController.h

@@ -1,5 +1,8 @@
 #pragma once
 
+#include <BAN/Optional.h>
+#include <BAN/Errors.h>
+
 #include <stdint.h>
 
 #define DISABLE_INTERRUPTS() asm volatile("cli")
@@ -37,6 +40,9 @@ namespace Kernel
 		static void initialize(bool force_pic);
 		static InterruptController& get();
 
+		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq) = 0;
+		virtual BAN::Optional<uint8_t> get_free_irq() = 0;
+
 		bool is_using_apic() const { return m_using_apic; }
 
 		void enter_acpi_mode();

kernel/include/kernel/PCI.h

@@ -79,7 +79,8 @@ namespace Kernel::PCI
 		uint16_t vendor_id() const { return m_vendor_id; }
 		uint16_t device_id() const { return m_device_id; }
 
-		BAN::ErrorOr<uint8_t> get_irq();
+		BAN::ErrorOr<void> reserve_irqs(uint8_t count);
+		uint8_t get_irq(uint8_t index);
 
 		BAN::ErrorOr<BAN::UniqPtr<BarRegion>> allocate_bar_region(uint8_t bar_num);
 
@@ -92,15 +93,15 @@ namespace Kernel::PCI
 		void enable_io_space();
 		void disable_io_space();
 
-		void enable_pin_interrupts();
-		void disable_pin_interrupts();
-
 	private:
 		void enumerate_capabilites();
 
 		void set_command_bits(uint16_t mask);
 		void unset_command_bits(uint16_t mask);
 
+		void enable_pin_interrupts();
+		void disable_pin_interrupts();
+
 	private:
 		const uint8_t m_bus;
 		const uint8_t m_dev;
@@ -114,6 +115,9 @@ namespace Kernel::PCI
 		uint16_t m_vendor_id;
 		uint16_t m_device_id;
 
+		uint32_t m_reserved_irqs { 0 };
+		uint8_t m_reserved_irq_count { 0 };
+
 		BAN::Optional<uint8_t> m_offset_msi;
 		BAN::Optional<uint8_t> m_offset_msi_x;
 	};

kernel/include/kernel/PIC.h

@@ -12,12 +12,16 @@ namespace Kernel
 		virtual void enable_irq(uint8_t) override;
 		virtual bool is_in_service(uint8_t) override;
 
+		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq) override;
+		virtual BAN::Optional<uint8_t> get_free_irq() override;
+
 		static void remap();
 		static void mask_all();
 
 	private:
 		static PIC* create();
 		friend class InterruptController;
+		uint16_t m_reserved_irqs { 0 };
 	};
 
 }