percpu.c

{
	size_t static_size = __per_cpu_end - __per_cpu_start;
	ssize_t unit_size;
	unsigned long delta;
	unsigned int cpu;

	/*
	 * Always reserve area for module percpu variables.  That's
	 * what the legacy allocator did.
	 */
	unit_size = pcpu_embed_first_chunk(static_size, PERCPU_MODULE_RESERVE,
					   PERCPU_DYNAMIC_RESERVE);
	if (unit_size < 0)
		panic("Failed to initialized percpu areas.");

	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
	for_each_possible_cpu(cpu)
		__per_cpu_offset[cpu] = delta + cpu * unit_size;
}
#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */