Kernel: Implement IPI broadcasting

kernel/arch/x86_64/IDT.cpp

@@ -10,7 +10,7 @@
 #include <kernel/Timer/PIT.h>
 
 #define ISR_LIST_X X(0) X(1) X(2) X(3) X(4) X(5) X(6) X(7) X(8) X(9) X(10) X(11) X(12) X(13) X(14) X(15) X(16) X(17) X(18) X(19) X(20) X(21) X(22) X(23) X(24) X(25) X(26) X(27) X(28) X(29) X(30) X(31)
-#define IRQ_LIST_X X(0) X(1) X(2) X(3) X(4) X(5) X(6) X(7) X(8) X(9) X(10) X(11) X(12) X(13) X(14) X(15) X(16) X(17) X(18) X(19) X(20) X(21) X(22) X(23) X(24) X(25) X(26) X(27) X(28) X(29) X(30) X(31)
+#define IRQ_LIST_X X(0) X(1) X(2) X(3) X(4) X(5) X(6) X(7) X(8) X(9) X(10) X(11) X(12) X(13) X(14) X(15) X(16) X(17) X(18) X(19) X(20) X(21) X(22) X(23) X(24) X(25) X(26) X(27) X(28) X(29) X(30) X(31) X(32)
 
 namespace Kernel
 {

kernel/arch/x86_64/interrupts.S

@@ -174,6 +174,7 @@ irq 28
 irq 29
 irq 30
 irq 31
+irq 32
 
 // arguments in RAX, RBX, RCX, RDX, RSI, RDI
 // System V ABI: RDI, RSI, RDX, RCX, R8, R9

kernel/include/kernel/APIC.h

@@ -19,6 +19,8 @@ namespace Kernel
 		virtual BAN::Optional<uint8_t> get_free_irq() override;
 
 		virtual void initialize_multiprocessor() override;
+		virtual void broadcast_ipi() override;
+		virtual void enable() override;
 
 	private:
 		uint32_t read_from_local_apic(ptrdiff_t);

kernel/include/kernel/IDT.h

@@ -7,6 +7,7 @@
 #include <stdint.h>
 
 constexpr uint8_t IRQ_VECTOR_BASE = 0x20;
+constexpr uint8_t IRQ_IPI = 32;
 
 namespace Kernel
 {

kernel/include/kernel/InterruptController.h

@@ -21,6 +21,8 @@ namespace Kernel
 		static InterruptController& get();
 
 		virtual void initialize_multiprocessor() = 0;
+		virtual void broadcast_ipi() = 0;
+		virtual void enable() = 0;
 
 		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq) = 0;
 		virtual BAN::Optional<uint8_t> get_free_irq() = 0;

kernel/include/kernel/PIC.h

@@ -17,6 +17,8 @@ namespace Kernel
 		virtual BAN::Optional<uint8_t> get_free_irq() override;
 
 		virtual void initialize_multiprocessor() override;
+		virtual void broadcast_ipi() override {}
+		virtual void enable() override {}
 
 		static void remap();
 		static void mask_all();

kernel/kernel/APIC.cpp

@@ -215,9 +215,8 @@ namespace Kernel
 			io_apic.max_redirs = io_apic.read(IOAPIC_MAX_REDIRS);
 		}
 
-		// Mask all interrupts
+		// Enable local apic
-		uint32_t sivr = apic->read_from_local_apic(LAPIC_SIV_REG);
+		apic->write_to_local_apic(LAPIC_SIV_REG, apic->read_from_local_apic(LAPIC_SIV_REG) | 0x1FF);
-		apic->write_to_local_apic(LAPIC_SIV_REG, sivr | 0x1FF);
 
 		return apic;
 	}
@@ -313,6 +312,28 @@ namespace Kernel
 		dprintln("{} processors started", *g_ap_running_count);
 	}
 
+	void APIC::broadcast_ipi()
+	{
+		write_to_local_apic(LAPIC_ICR_HI_REG, (read_from_local_apic(LAPIC_ICR_HI_REG) & 0x00FFFFFF) | 0xFF000000);
+		write_to_local_apic(LAPIC_ICR_LO_REG,
+			(read_from_local_apic(LAPIC_ICR_LO_REG) & ICR_LO_reserved_mask)
+			| ICR_LO_delivery_mode_fixed
+			| ICR_LO_destination_mode_physical
+			| ICR_LO_level_assert
+			| ICR_LO_trigger_mode_level
+			| ICR_LO_destination_shorthand_all_excluding_self
+			| (IRQ_VECTOR_BASE + IRQ_IPI)
+		);
+		while ((read_from_local_apic(LAPIC_ICR_LO_REG) & ICR_LO_delivery_status_send_pending) == ICR_LO_delivery_status_send_pending)
+			__builtin_ia32_pause();
+	}
+
+	void APIC::enable()
+	{
+		write_to_local_apic(LAPIC_SIV_REG, read_from_local_apic(LAPIC_SIV_REG) | 0x1FF);
+	}
+
+
 	uint32_t APIC::read_from_local_apic(ptrdiff_t offset)
 	{
 		return MMIO::read32(m_local_apic_vaddr + offset);
@@ -370,7 +391,8 @@ namespace Kernel
 
 		redir.vector = IRQ_VECTOR_BASE + irq;
 		redir.mask = 0;
-		redir.destination = m_processors.front().apic_id;
+		// FIXME: distribute IRQs more evenly?
+		redir.destination = Kernel::Processor::bsb_id();
 
 		ioapic->write(IOAPIC_REDIRS + gsi * 2,		redir.lo_dword);
 		ioapic->write(IOAPIC_REDIRS + gsi * 2 + 1,	redir.hi_dword);

kernel/kernel/kernel.cpp

@@ -214,6 +214,7 @@ extern "C" void ap_main()
 	Processor::initialize();
 	PageTable::kernel().initial_load();
 	Processor::allocate_idle_thread();
+	InterruptController::get().enable();
 
 	dprintln("ap{} initialized", Processor::current_id());