linux/arch/x86/include/asm/cpu.h
Fenghua Yu e1c467e690 x86, hotplug: Wake up CPU0 via NMI instead of INIT, SIPI, SIPI
Instead of waiting for STARTUP after INITs, BSP will execute the BIOS boot-strap
code which is not a desired behavior for waking up BSP. To avoid the boot-strap
code, wake up CPU0 by NMI instead.

This works to wake up soft offlined CPU0 only. If CPU0 is hard offlined (i.e.
physically hot removed and then hot added), NMI won't wake it up. We'll change
this code in the future to wake up hard offlined CPU0 if real platform and
request are available.

AP is still waken up as before by INIT, SIPI, SIPI sequence.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352896613-25957-1-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-14 15:28:03 -08:00

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C

#ifndef _ASM_X86_CPU_H
#define _ASM_X86_CPU_H
#include <linux/device.h>
#include <linux/cpu.h>
#include <linux/topology.h>
#include <linux/nodemask.h>
#include <linux/percpu.h>
#ifdef CONFIG_SMP
extern void prefill_possible_map(void);
#else /* CONFIG_SMP */
static inline void prefill_possible_map(void) {}
#define cpu_physical_id(cpu) boot_cpu_physical_apicid
#define safe_smp_processor_id() 0
#define stack_smp_processor_id() 0
#endif /* CONFIG_SMP */
struct x86_cpu {
struct cpu cpu;
};
#ifdef CONFIG_HOTPLUG_CPU
extern int arch_register_cpu(int num);
extern void arch_unregister_cpu(int);
extern void __cpuinit start_cpu0(void);
#endif
DECLARE_PER_CPU(int, cpu_state);
int mwait_usable(const struct cpuinfo_x86 *);
#endif /* _ASM_X86_CPU_H */