replace asm volatile("pause") with function

arch/x86_64/apic.c

@@ -6,6 +6,7 @@
 #include <zinnia/pmap.h>
 #include <zinnia/utils.h>
 #include <zinnia/vma.h>
+#include <arch/cpu.h>
 #include <stdint.h>
 #include <x86_64/apic.h>
 #include <x86_64/asm.h>
@@ -129,7 +130,7 @@ void lapic_send_ipi(
 
     if (lapic->xapic_regs) {
         while (mmio_field_get(APIC_ICR_DELIVERY_STATUS, lapic_read_icr(lapic)) == APIC_DELIVERY_STATUS_PENDING)
-            asm volatile("pause");
+            arch_cpu_pause();
     }
 }
 

arch/x86_64/include/bits/cpu.h

@@ -0,0 +1,5 @@
+#pragma once
+
+static inline void arch_cpu_pause() {
+    asm volatile("pause");
+}

arch/x86_64/serial.c

@@ -1,6 +1,7 @@
 #include <zinnia/console.h>
 #include <zinnia/init.h>
 #include <zinnia/initgraph.h>
+#include <arch/cpu.h>
 #include <stdint.h>
 #include <x86_64/asm.h>
 
@@ -13,7 +14,7 @@ static bool is_ready() {
 static void serial_write(struct console* con, const char* buf, size_t count) {
     for (size_t i = 0; i < count; i++) {
         while (!is_ready())
-            asm volatile("pause");
+            arch_cpu_pause();
 
         asm_outb(COM1_BASE, buf[i]);
     }