kernel: implement cpu IDs and per-cpu variables

kernel/cpu.c

@@ -0,0 +1,41 @@
+#include <socks/cpu.h>
+#include <socks/percpu.h>
+#include <socks/bitmap.h>
+
+DECLARE_BITMAP(cpu_available, CPU_MAX);
+DECLARE_BITMAP(cpu_online, CPU_MAX);
+
+DEFINE_PERCPU_VAR(cpu_data_t, cpu_data);
+
+cpu_data_t *get_this_cpu(void)
+{
+	return percpu_get(&cpu_data);
+}
+
+void put_cpu(cpu_data_t *cpu)
+{
+	percpu_put(cpu);
+}
+
+void cpu_set_available(unsigned int cpu_id)
+{
+	if (cpu_id >= CPU_MAX) {
+		return;
+	}
+
+	bitmap_set(cpu_available, cpu_id);
+}
+
+void cpu_set_online(unsigned int cpu_id)
+{
+	if (cpu_id >= CPU_MAX) {
+		return;
+	}
+
+	bitmap_set(cpu_online, cpu_id);
+}
+
+unsigned int cpu_get_highest_available(void)
+{
+	return bitmap_highest_set(cpu_available, CPU_MAX);
+}