acpi: calibrate local APIC timer on BSP

arch/x86_64/include/arch/acpi/io_apic.hpp

@@ -33,6 +33,8 @@ namespace arch::acpi {
 		kern_status_t read_irq(unsigned int index, irq_entry &entry);
 		void write_irq(unsigned int index, const irq_entry &entry);
 		void map_irq(unsigned int src, unsigned int dest);
+		void mask_irq(unsigned int vec);
+		void unmask_irq(unsigned int vec, unsigned int dest_cpu = (unsigned int)-1);
 	};
 }
 

arch/x86_64/include/arch/acpi/local_apic.hpp

@@ -3,11 +3,22 @@
 
 #include <stdint.h>
 
+#define APIC_LVT_INT_MASKED 0x10000
+#define APIC_LVT_TIMER_MODE_PERIODIC 0x20000
+
 namespace arch::acpi {
 	class local_apic {
 		uint32_t *base_ = nullptr;
 
 	public:
+		enum {
+			EOI = 0xB0,
+			LVT_TIMER = 320,
+			TIMER_INITCOUNT = 0x380,
+			TIMER_CURCOUNT = 0x390,
+			TIMER_DIV = 0x3E0,
+		};
+
 		local_apic(uint32_t *base);
 
 		uint32_t read(uint32_t reg);