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Commit 8227dce7 authored by Alex Nixon's avatar Alex Nixon Committed by Ingo Molnar
Browse files

x86: separate generic cpu disabling code from APIC writes in cpu_disable 



It allows paravirt implementations of cpu_disable to share the
cpu_disable_common code, without having to take on board APIC
writes, which may not be appropriate.

Signed-off-by: default avatarAlex Nixon <alex.nixon@citrix.com>
Acked-by: default avatarJeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a21f5d88

arch/x86/kernel/smpboot.c

+23 −17
Original line number Diff line number Diff line
@@ -1346,25 +1346,9 @@ static void __ref remove_cpu_from_maps(int cpu) 
	numa_remove_cpu(cpu);

}



int native_cpu_disable(void)

void cpu_disable_common(void)

{

	int cpu = smp_processor_id();



	/*

	 * Perhaps use cpufreq to drop frequency, but that could go

	 * into generic code.

	 *

	 * We won't take down the boot processor on i386 due to some

	 * interrupts only being able to be serviced by the BSP.

	 * Especially so if we're not using an IOAPIC	-zwane

	 */

	if (cpu == 0)

		return -EBUSY;



	if (nmi_watchdog == NMI_LOCAL_APIC)

		stop_apic_nmi_watchdog(NULL);

	clear_local_APIC();



	/*

	 * HACK:

	 * Allow any queued timer interrupts to get serviced
@@ -1382,6 +1366,28 @@ int native_cpu_disable(void) 
	remove_cpu_from_maps(cpu);

	unlock_vector_lock();

	fixup_irqs(cpu_online_map);

}



int native_cpu_disable(void)

{

	int cpu = smp_processor_id();



	/*

	 * Perhaps use cpufreq to drop frequency, but that could go

	 * into generic code.

	 *

	 * We won't take down the boot processor on i386 due to some

	 * interrupts only being able to be serviced by the BSP.

	 * Especially so if we're not using an IOAPIC	-zwane

	 */

	if (cpu == 0)

		return -EBUSY;



	if (nmi_watchdog == NMI_LOCAL_APIC)

		stop_apic_nmi_watchdog(NULL);

	clear_local_APIC();



	cpu_disable_common();

	return 0;

}

include/asm-x86/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ static inline void arch_send_call_function_ipi(cpumask_t mask) 
	smp_ops.send_call_func_ipi(mask);

}



void cpu_disable_common(void);

void native_smp_prepare_boot_cpu(void);

void native_smp_prepare_cpus(unsigned int max_cpus);

void native_smp_cpus_done(unsigned int max_cpus);