Commit 30106c17 authored by Fenghua Yu's avatar Fenghua Yu Committed by H. Peter Anvin
Browse files

x86, hotplug: Support functions for CPU0 online/offline 



Add smp_store_boot_cpu_info() to store cpu info for BSP during boot time.

Now smp_store_cpu_info() stores cpu info for bringing up BSP or AP after
it's offline.

Continue to online CPU0 in native_cpu_up().

Continue to offline CPU0 in native_cpu_disable().

Signed-off-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-5-git-send-email-fenghua.yu@intel.com


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 4d25031a

arch/x86/include/asm/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -166,6 +166,7 @@ void native_send_call_func_ipi(const struct cpumask *mask); 
void native_send_call_func_single_ipi(int cpu);

void x86_idle_thread_init(unsigned int cpu, struct task_struct *idle);



void smp_store_boot_cpu_info(void);

void smp_store_cpu_info(int id);

#define cpu_physical_id(cpu)	per_cpu(x86_cpu_to_apicid, cpu)

arch/x86/kernel/smpboot.c

+18 −20
Original line number Diff line number Diff line
@@ -125,8 +125,8 @@ EXPORT_PER_CPU_SYMBOL(cpu_info); 
atomic_t init_deasserted;



/*

 * Report back to the Boot Processor.

 * Running on AP.

 * Report back to the Boot Processor during boot time or to the caller processor

 * during CPU online.

 */

static void __cpuinit smp_callin(void)

{
@@ -279,18 +279,29 @@ notrace static void __cpuinit start_secondary(void *unused) 
	cpu_idle();

}



void __init smp_store_boot_cpu_info(void)

{

	int id = 0; /* CPU 0 */

	struct cpuinfo_x86 *c = &cpu_data(id);



	*c = boot_cpu_data;

	c->cpu_index = id;

}



/*

 * The bootstrap kernel entry code has set these up. Save them for

 * a given CPU

 */



void __cpuinit smp_store_cpu_info(int id)

{

	struct cpuinfo_x86 *c = &cpu_data(id);



	*c = boot_cpu_data;

	c->cpu_index = id;

	if (id != 0)

	/*

	 * During boot time, CPU0 has this setup already. Save the info when

	 * bringing up AP or offlined CPU0.

	 */

	identify_secondary_cpu(c);

}
@@ -795,7 +806,7 @@ int __cpuinit native_cpu_up(unsigned int cpu, struct task_struct *tidle) 


	pr_debug("++++++++++++++++++++=_---CPU UP  %u\n", cpu);



	if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||

	if (apicid == BAD_APICID ||

	    !physid_isset(apicid, phys_cpu_present_map) ||

	    !apic->apic_id_valid(apicid)) {

		pr_err("%s: bad cpu %d\n", __func__, cpu);
@@ -990,7 +1001,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus) 
	/*

	 * Setup boot CPU information

	 */

	smp_store_cpu_info(0); /* Final full version of the data */

	smp_store_boot_cpu_info(); /* Final full version of the data */

	cpumask_copy(cpu_callin_mask, cpumask_of(0));

	mb();
@@ -1214,19 +1225,6 @@ void cpu_disable_common(void) 


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;



	clear_local_APIC();



	cpu_disable_common();

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