/* * lib/smp_processor_id.c * * DEBUG_PREEMPT variant of smp_processor_id(). */#include <linux/export.h>#include <linux/kallsyms.h>#include <linux/sched.h> notrace unsigned int debug_smp_processor_id(void){	int this_cpu = raw_smp_processor_id(); 	if (likely(preempt_count()))		goto out; 	if (irqs_disabled())		goto out; 	/*	 * Kernel threads bound to a single CPU can safely use	 * smp_processor_id():	 */	if (cpumask_equal(tsk_cpus_allowed(current), cpumask_of(this_cpu)))		goto out; 	/*	 * It is valid to assume CPU-locality during early bootup:	 */	if (system_state != SYSTEM_RUNNING)		goto out; 	/*	 * Avoid recursion:	 */	preempt_disable_notrace(); 	if (!printk_ratelimit())		goto out_enable; 	printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "			"code: %s/%d\n",			preempt_count() - 1, current->comm, current->pid);	print_symbol("caller is %s\n", (long)__builtin_return_address(0));	dump_stack(); out_enable:	preempt_enable_no_resched_notrace();out:	return this_cpu;} EXPORT_SYMBOL(debug_smp_processor_id);