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x86, hotplug: Support functions for CPU0 online/offline

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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: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-5-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Fenghua Yu 2012-11-13 11:32:41 -08:00 committed by H. Peter Anvin
parent 4d25031a81
commit 30106c1743
2 changed files with 19 additions and 20 deletions
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1
arch/x86/include/asm/smp.h
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@ -166,6 +166,7 @@ void native_send_call_func_ipi(const struct cpumask *mask);
void native_send_call_func_single_ipi(int cpu); void native_send_call_func_single_ipi(int cpu);
void x86_idle_thread_init(unsigned int cpu, struct task_struct *idle); 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); void smp_store_cpu_info(int id);
#define cpu_physical_id(cpu) per_cpu(x86_cpu_to_apicid, cpu) #define cpu_physical_id(cpu) per_cpu(x86_cpu_to_apicid, cpu)

38
arch/x86/kernel/smpboot.c
View File

@ -125,8 +125,8 @@ EXPORT_PER_CPU_SYMBOL(cpu_info);
atomic_t init_deasserted; atomic_t init_deasserted;
/* /*
* Report back to the Boot Processor. * Report back to the Boot Processor during boot time or to the caller processor
* Running on AP. * during CPU online.
*/ */
static void __cpuinit smp_callin(void) static void __cpuinit smp_callin(void)
{ {
@ -279,19 +279,30 @@ notrace static void __cpuinit start_secondary(void *unused)
cpu_idle(); 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 * The bootstrap kernel entry code has set these up. Save them for
* a given CPU * a given CPU
*/ */
void __cpuinit smp_store_cpu_info(int id) void __cpuinit smp_store_cpu_info(int id)
{ {
struct cpuinfo_x86 *c = &cpu_data(id); struct cpuinfo_x86 *c = &cpu_data(id);
*c = boot_cpu_data; *c = boot_cpu_data;
c->cpu_index = id; c->cpu_index = id;
if (id != 0) /*
identify_secondary_cpu(c); * During boot time, CPU0 has this setup already. Save the info when
* bringing up AP or offlined CPU0.
*/
identify_secondary_cpu(c);
} }
static bool __cpuinit static bool __cpuinit
@ -795,7 +806,7 @@ int __cpuinit native_cpu_up(unsigned int cpu, struct task_struct *tidle)
pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu); 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) || !physid_isset(apicid, phys_cpu_present_map) ||
!apic->apic_id_valid(apicid)) { !apic->apic_id_valid(apicid)) {
pr_err("%s: bad cpu %d\n", __func__, cpu); 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 * 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)); cpumask_copy(cpu_callin_mask, cpumask_of(0));
mb(); mb();
@ -1214,19 +1225,6 @@ void cpu_disable_common(void)
int native_cpu_disable(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(); clear_local_APIC();
cpu_disable_common(); cpu_disable_common();