1#include <linux/kernel.h>
 2#include <linux/smp.h>
 3#include <linux/reboot.h>
 4#include <linux/kexec.h>
 5#include <linux/bootmem.h>
 6#include <linux/crash_dump.h>
 7#include <linux/delay.h>
 8#include <linux/irq.h>
 9#include <linux/types.h>
10#include <linux/sched.h>
11
12/* This keeps a track of which one is crashing cpu. */
13static int crashing_cpu = -1;
14static cpumask_t cpus_in_crash = CPU_MASK_NONE;
15
16#ifdef CONFIG_SMP
17static void crash_shutdown_secondary(void *ignore)
18{
19	struct pt_regs *regs;
20	int cpu = smp_processor_id();
21
22	regs = task_pt_regs(current);
23
24	if (!cpu_online(cpu))
25		return;
26
27	local_irq_disable();
28	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
29		crash_save_cpu(regs, cpu);
30	cpumask_set_cpu(cpu, &cpus_in_crash);
31
32	while (!atomic_read(&kexec_ready_to_reboot))
33		cpu_relax();
34	relocated_kexec_smp_wait(NULL);
35	/* NOTREACHED */
36}
37
38static void crash_kexec_prepare_cpus(void)
39{
40	unsigned int msecs;
41
42	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
43
44	dump_send_ipi(crash_shutdown_secondary);
45	smp_wmb();
46
47	/*
48	 * The crash CPU sends an IPI and wait for other CPUs to
49	 * respond. Delay of at least 10 seconds.
50	 */
51	pr_emerg("Sending IPI to other cpus...\n");
52	msecs = 10000;
53	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
54		cpu_relax();
55		mdelay(1);
56	}
57}
58
59#else /* !defined(CONFIG_SMP)  */
60static void crash_kexec_prepare_cpus(void) {}
61#endif /* !defined(CONFIG_SMP)	*/
62
63void default_machine_crash_shutdown(struct pt_regs *regs)
64{
65	local_irq_disable();
66	crashing_cpu = smp_processor_id();
67	crash_save_cpu(regs, crashing_cpu);
68	crash_kexec_prepare_cpus();
69	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
70}