1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/kernel.h>
 3#include <linux/smp.h>
 4#include <linux/reboot.h>
 5#include <linux/kexec.h>
 6#include <linux/bootmem.h>
 7#include <linux/crash_dump.h>
 8#include <linux/delay.h>
 9#include <linux/irq.h>
10#include <linux/types.h>
11#include <linux/sched.h>
12#include <linux/sched/task_stack.h>
13
14/* This keeps a track of which one is crashing cpu. */
15static int crashing_cpu = -1;
16static cpumask_t cpus_in_crash = CPU_MASK_NONE;
17
18#ifdef CONFIG_SMP
19static void crash_shutdown_secondary(void *passed_regs)
20{
21	struct pt_regs *regs = passed_regs;
22	int cpu = smp_processor_id();
23
24	/*
25	 * If we are passed registers, use those.  Otherwise get the
26	 * regs from the last interrupt, which should be correct, as
27	 * we are in an interrupt.  But if the regs are not there,
28	 * pull them from the top of the stack.  They are probably
29	 * wrong, but we need something to keep from crashing again.
30	 */
31	if (!regs)
32		regs = get_irq_regs();
33	if (!regs)
34		regs = task_pt_regs(current);
35
36	if (!cpu_online(cpu))
37		return;
38
39	local_irq_disable();
40	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
41		crash_save_cpu(regs, cpu);
42	cpumask_set_cpu(cpu, &cpus_in_crash);
43
44	while (!atomic_read(&kexec_ready_to_reboot))
45		cpu_relax();
46	relocated_kexec_smp_wait(NULL);
47	/* NOTREACHED */
48}
49
50static void crash_kexec_prepare_cpus(void)
51{
52	static int cpus_stopped;
53	unsigned int msecs;
54	unsigned int ncpus;
55
56	if (cpus_stopped)
57		return;
58
59	ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
60
61	smp_call_function(crash_shutdown_secondary, NULL, 0);
62	smp_wmb();
63
64	/*
65	 * The crash CPU sends an IPI and wait for other CPUs to
66	 * respond. Delay of at least 10 seconds.
67	 */
68	pr_emerg("Sending IPI to other cpus...\n");
69	msecs = 10000;
70	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
71		cpu_relax();
72		mdelay(1);
73	}
74
75	cpus_stopped = 1;
76}
77
78/* Override the weak function in kernel/panic.c */
79void crash_smp_send_stop(void)
80{
81	if (_crash_smp_send_stop)
82		_crash_smp_send_stop();
83
84	crash_kexec_prepare_cpus();
85}
86
87#else /* !defined(CONFIG_SMP)  */
88static void crash_kexec_prepare_cpus(void) {}
89#endif /* !defined(CONFIG_SMP)	*/
90
91void default_machine_crash_shutdown(struct pt_regs *regs)
92{
93	local_irq_disable();
94	crashing_cpu = smp_processor_id();
95	crash_save_cpu(regs, crashing_cpu);
96	crash_kexec_prepare_cpus();
97	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
98}

 
 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}