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Commit 2ddded21 authored by Eduardo Habkost's avatar Eduardo Habkost Committed by Ingo Molnar
Browse files

x86: move nmi_shootdown_cpus() to reboot.c 



Impact: make nmi_shootdown_cpus() available to the rest of the x86 platform

Now nmi_shootdown_cpus() is ready to be used by non-kdump code also.
Move it to reboot.c.

Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c370e5e0

arch/x86/kernel/crash.c

+0 −76
Original line number Diff line number Diff line
@@ -32,12 +32,6 @@ 


#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)



/* This keeps a track of which one is crashing cpu. */

static int crashing_cpu;

static nmi_shootdown_cb shootdown_callback;



static atomic_t waiting_for_crash_ipi;



static void kdump_nmi_callback(int cpu, struct die_args *args)

{

	struct pt_regs *regs;
@@ -58,76 +52,6 @@ static void kdump_nmi_callback(int cpu, struct die_args *args) 
	disable_local_APIC();

}



static int crash_nmi_callback(struct notifier_block *self,

			unsigned long val, void *data)

{

	int cpu;



	if (val != DIE_NMI_IPI)

		return NOTIFY_OK;



	cpu = raw_smp_processor_id();



	/* Don't do anything if this handler is invoked on crashing cpu.

	 * Otherwise, system will completely hang. Crashing cpu can get

	 * an NMI if system was initially booted with nmi_watchdog parameter.

	 */

	if (cpu == crashing_cpu)

		return NOTIFY_STOP;

	local_irq_disable();



	shootdown_callback(cpu, (struct die_args *)data);



	atomic_dec(&waiting_for_crash_ipi);

	/* Assume hlt works */

	halt();

	for (;;)

		cpu_relax();



	return 1;

}



static void smp_send_nmi_allbutself(void)

{

	cpumask_t mask = cpu_online_map;

	cpu_clear(safe_smp_processor_id(), mask);

	if (!cpus_empty(mask))

		send_IPI_mask(mask, NMI_VECTOR);

}



static struct notifier_block crash_nmi_nb = {

	.notifier_call = crash_nmi_callback,

};



void nmi_shootdown_cpus(nmi_shootdown_cb callback)

{

	unsigned long msecs;



	/* Make a note of crashing cpu. Will be used in NMI callback.*/

	crashing_cpu = safe_smp_processor_id();



	shootdown_callback = callback;



	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);

	/* Would it be better to replace the trap vector here? */

	if (register_die_notifier(&crash_nmi_nb))

		return;		/* return what? */

	/* Ensure the new callback function is set before sending

	 * out the NMI

	 */

	wmb();



	smp_send_nmi_allbutself();



	msecs = 1000; /* Wait at most a second for the other cpus to stop */

	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {

		mdelay(1);

		msecs--;

	}



	/* Leave the nmi callback set */

}



static void kdump_nmi_shootdown_cpus(void)

{

	nmi_shootdown_cpus(kdump_nmi_callback);

arch/x86/kernel/reboot.c

+83 −0
Original line number Diff line number Diff line
@@ -21,6 +21,9 @@ 
# include <asm/iommu.h>

#endif



#include <mach_ipi.h>





/*

 * Power off function, if any

 */
@@ -514,3 +517,83 @@ void machine_crash_shutdown(struct pt_regs *regs) 
	machine_ops.crash_shutdown(regs);

}

#endif





#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)



/* This keeps a track of which one is crashing cpu. */

static int crashing_cpu;

static nmi_shootdown_cb shootdown_callback;



static atomic_t waiting_for_crash_ipi;



static int crash_nmi_callback(struct notifier_block *self,

			unsigned long val, void *data)

{

	int cpu;



	if (val != DIE_NMI_IPI)

		return NOTIFY_OK;



	cpu = raw_smp_processor_id();



	/* Don't do anything if this handler is invoked on crashing cpu.

	 * Otherwise, system will completely hang. Crashing cpu can get

	 * an NMI if system was initially booted with nmi_watchdog parameter.

	 */

	if (cpu == crashing_cpu)

		return NOTIFY_STOP;

	local_irq_disable();



	shootdown_callback(cpu, (struct die_args *)data);



	atomic_dec(&waiting_for_crash_ipi);

	/* Assume hlt works */

	halt();

	for (;;)

		cpu_relax();



	return 1;

}



static void smp_send_nmi_allbutself(void)

{

	cpumask_t mask = cpu_online_map;

	cpu_clear(safe_smp_processor_id(), mask);

	if (!cpus_empty(mask))

		send_IPI_mask(mask, NMI_VECTOR);

}



static struct notifier_block crash_nmi_nb = {

	.notifier_call = crash_nmi_callback,

};



void nmi_shootdown_cpus(nmi_shootdown_cb callback)

{

	unsigned long msecs;



	/* Make a note of crashing cpu. Will be used in NMI callback.*/

	crashing_cpu = safe_smp_processor_id();



	shootdown_callback = callback;



	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);

	/* Would it be better to replace the trap vector here? */

	if (register_die_notifier(&crash_nmi_nb))

		return;		/* return what? */

	/* Ensure the new callback function is set before sending

	 * out the NMI

	 */

	wmb();



	smp_send_nmi_allbutself();



	msecs = 1000; /* Wait at most a second for the other cpus to stop */

	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {

		mdelay(1);

		msecs--;

	}



	/* Leave the nmi callback set */

}

#endif