[mirror_ubuntu-artful-kernel.git] / arch / mips / kernel / crash.c

#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/kexec.h>
#include <linux/bootmem.h>
#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <linux/sched.h>

/* This keeps a track of which one is crashing cpu. */
static int crashing_cpu = -1;
static cpumask_t cpus_in_crash = CPU_MASK_NONE;

#ifdef CONFIG_SMP
static void crash_shutdown_secondary(void *passed_regs)
{
	struct pt_regs *regs = passed_regs;
	int cpu = smp_processor_id();

	/*
	 * If we are passed registers, use those.  Otherwise get the
	 * regs from the last interrupt, which should be correct, as
	 * we are in an interrupt.  But if the regs are not there,
	 * pull them from the top of the stack.  They are probably
	 * wrong, but we need something to keep from crashing again.
	 */
	if (!regs)
		regs = get_irq_regs();
	if (!regs)
		regs = task_pt_regs(current);

	if (!cpu_online(cpu))
		return;

	local_irq_disable();
	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
		crash_save_cpu(regs, cpu);
	cpumask_set_cpu(cpu, &cpus_in_crash);

	while (!atomic_read(&kexec_ready_to_reboot))
		cpu_relax();
	relocated_kexec_smp_wait(NULL);
	/* NOTREACHED */
}

static void crash_kexec_prepare_cpus(void)
{
	static int cpus_stopped;
	unsigned int msecs;
	unsigned int ncpus;

	if (cpus_stopped)
		return;

	ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */

	smp_call_function(crash_shutdown_secondary, NULL, 0);
	smp_wmb();

	/*
	 * The crash CPU sends an IPI and wait for other CPUs to
	 * respond. Delay of at least 10 seconds.
	 */
	pr_emerg("Sending IPI to other cpus...\n");
	msecs = 10000;
	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
		cpu_relax();
		mdelay(1);
	}

	cpus_stopped = 1;
}

/* Override the weak function in kernel/panic.c */
void crash_smp_send_stop(void)
{
	if (_crash_smp_send_stop)
		_crash_smp_send_stop();

	crash_kexec_prepare_cpus();
}

#else /* !defined(CONFIG_SMP)  */
static void crash_kexec_prepare_cpus(void) {}
#endif /* !defined(CONFIG_SMP)	*/

void default_machine_crash_shutdown(struct pt_regs *regs)
{
	local_irq_disable();
	crashing_cpu = smp_processor_id();
	crash_save_cpu(regs, crashing_cpu);
	crash_kexec_prepare_cpus();
	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
}
Commit	Line	Data
7aa1c8f4 RB	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>
7aa1c8f4 RB	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. */
	13	static int crashing_cpu = -1;
	14	static cpumask_t cpus_in_crash = CPU_MASK_NONE;
	15
	16	#ifdef CONFIG_SMP
c80e1b62	17	static void crash_shutdown_secondary(void *passed_regs)
7aa1c8f4	18	{
c80e1b62	19	struct pt_regs *regs = passed_regs;
7aa1c8f4 RB	20	int cpu = smp_processor_id();
7aa1c8f4 RB	21
c80e1b62 CM	22	/*
	23	* If we are passed registers, use those. Otherwise get the
	24	* regs from the last interrupt, which should be correct, as
	25	* we are in an interrupt. But if the regs are not there,
	26	* pull them from the top of the stack. They are probably
	27	* wrong, but we need something to keep from crashing again.
	28	*/
	29	if (!regs)
	30	regs = get_irq_regs();
	31	if (!regs)
	32	regs = task_pt_regs(current);
7aa1c8f4 RB	33
	34	if (!cpu_online(cpu))
	35	return;
	36
	37	local_irq_disable();
8dd92891	38	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
7aa1c8f4	39	crash_save_cpu(regs, cpu);
8dd92891	40	cpumask_set_cpu(cpu, &cpus_in_crash);
7aa1c8f4 RB	41
	42	while (!atomic_read(&kexec_ready_to_reboot))
	43	cpu_relax();
	44	relocated_kexec_smp_wait(NULL);
	45	/* NOTREACHED */
	46	}
	47
	48	static void crash_kexec_prepare_cpus(void)
	49	{
54c721b8	50	static int cpus_stopped;
7aa1c8f4	51	unsigned int msecs;
54c721b8	52	unsigned int ncpus;
7aa1c8f4	53
54c721b8 HK	54	if (cpus_stopped)
	55	return;
	56
	57	ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
7aa1c8f4	58
c83c2eed	59	smp_call_function(crash_shutdown_secondary, NULL, 0);
7aa1c8f4 RB	60	smp_wmb();
	61
	62	/*
	63	* The crash CPU sends an IPI and wait for other CPUs to
	64	* respond. Delay of at least 10 seconds.
	65	*/
	66	pr_emerg("Sending IPI to other cpus...\n");
	67	msecs = 10000;
8dd92891	68	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
7aa1c8f4 RB	69	cpu_relax();
	70	mdelay(1);
	71	}
54c721b8 HK	72
	73	cpus_stopped = 1;
	74	}
	75
	76	/* Override the weak function in kernel/panic.c */
	77	void crash_smp_send_stop(void)
	78	{
	79	if (_crash_smp_send_stop)
	80	_crash_smp_send_stop();
	81
	82	crash_kexec_prepare_cpus();
7aa1c8f4 RB	83	}
	84
	85	#else /* !defined(CONFIG_SMP) */
	86	static void crash_kexec_prepare_cpus(void) {}
70342287	87	#endif /* !defined(CONFIG_SMP) */
7aa1c8f4 RB	88
	89	void default_machine_crash_shutdown(struct pt_regs *regs)
	90	{
	91	local_irq_disable();
	92	crashing_cpu = smp_processor_id();
	93	crash_save_cpu(regs, crashing_cpu);
	94	crash_kexec_prepare_cpus();
8dd92891	95	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
7aa1c8f4	96	}