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// 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/memblock.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	/* We won't be sent IPIs any more. */
 40	set_cpu_online(cpu, false);
 41
 42	local_irq_disable();
 43	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
 44		crash_save_cpu(regs, cpu);
 45	cpumask_set_cpu(cpu, &cpus_in_crash);
 46
 47	while (!atomic_read(&kexec_ready_to_reboot))
 48		cpu_relax();
 49
 50	kexec_reboot();
 51
 52	/* NOTREACHED */
 53}
 54
 55static void crash_kexec_prepare_cpus(void)
 56{
 57	static int cpus_stopped;
 58	unsigned int msecs;
 59	unsigned int ncpus;
 60
 61	if (cpus_stopped)
 62		return;
 63
 64	ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
 65
 66	smp_call_function(crash_shutdown_secondary, NULL, 0);
 67	smp_wmb();
 68
 69	/*
 70	 * The crash CPU sends an IPI and wait for other CPUs to
 71	 * respond. Delay of at least 10 seconds.
 72	 */
 73	pr_emerg("Sending IPI to other cpus...\n");
 74	msecs = 10000;
 75	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
 76		cpu_relax();
 77		mdelay(1);
 78	}
 79
 80	cpus_stopped = 1;
 81}
 82
 83/* Override the weak function in kernel/panic.c */
 84void crash_smp_send_stop(void)
 85{
 86	if (_crash_smp_send_stop)
 87		_crash_smp_send_stop();
 88
 89	crash_kexec_prepare_cpus();
 90}
 91
 92#else /* !defined(CONFIG_SMP)  */
 93static void crash_kexec_prepare_cpus(void) {}
 94#endif /* !defined(CONFIG_SMP)	*/
 95
 96void default_machine_crash_shutdown(struct pt_regs *regs)
 97{
 98	local_irq_disable();
 99	crashing_cpu = smp_processor_id();
100	crash_save_cpu(regs, crashing_cpu);
101	crash_kexec_prepare_cpus();
102	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
103}