1. 根目录:
2. arch
3. x86
4. include
5. asm
6. smp.h

#ifndef _ASM_X86_SMP_H
#define _ASM_X86_SMP_H
#ifndef __ASSEMBLY__
#include <linux/cpumask.h>
#include <asm/percpu.h>

/*
 * We need the APIC definitions automatically as part of 'smp.h'
 */
#ifdef CONFIG_X86_LOCAL_APIC
# include <asm/mpspec.h>
# include <asm/apic.h>
# ifdef CONFIG_X86_IO_APIC
#  include <asm/io_apic.h>
# endif
#endif
#include <asm/thread_info.h>
#include <asm/cpumask.h>
#include <asm/cpufeature.h>

extern int smp_num_siblings;
extern unsigned int num_processors;

static inline bool cpu_has_ht_siblings(void)
{
	bool has_siblings = false;
#ifdef CONFIG_SMP
	has_siblings = cpu_has_ht && smp_num_siblings > 1;
#endif
	return has_siblings;
}

DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
/* cpus sharing the last level cache: */
DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);
DECLARE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id);
DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);

static inline struct cpumask *cpu_sibling_mask(int cpu)
{
	return per_cpu(cpu_sibling_map, cpu);
}

static inline struct cpumask *cpu_core_mask(int cpu)
{
	return per_cpu(cpu_core_map, cpu);
}

static inline struct cpumask *cpu_llc_shared_mask(int cpu)
{
	return per_cpu(cpu_llc_shared_map, cpu);
}

DECLARE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid);
DECLARE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid);
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
DECLARE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid);
#endif

/* Static state in head.S used to set up a CPU */
extern unsigned long stack_start; /* Initial stack pointer address */

struct task_struct;

struct smp_ops {
	void (*smp_prepare_boot_cpu)(void);
	void (*smp_prepare_cpus)(unsigned max_cpus);
	void (*smp_cpus_done)(unsigned max_cpus);

	void (*stop_other_cpus)(int wait);
	void (*smp_send_reschedule)(int cpu);

	int (*cpu_up)(unsigned cpu, struct task_struct *tidle);
	int (*cpu_disable)(void);
	void (*cpu_die)(unsigned int cpu);
	void (*play_dead)(void);

	void (*send_call_func_ipi)(const struct cpumask *mask);
	void (*send_call_func_single_ipi)(int cpu);
};

/* Globals due to paravirt */
extern void set_cpu_sibling_map(int cpu);

#ifdef CONFIG_SMP
#ifndef CONFIG_PARAVIRT
#define startup_ipi_hook(phys_apicid, start_eip, start_esp) do { } while (0)
#endif
extern struct smp_ops smp_ops;

static inline void smp_send_stop(void)
{
	smp_ops.stop_other_cpus(0);
}

static inline void stop_other_cpus(void)
{
	smp_ops.stop_other_cpus(1);
}

static inline void smp_prepare_boot_cpu(void)
{
	smp_ops.smp_prepare_boot_cpu();
}

static inline void smp_prepare_cpus(unsigned int max_cpus)
{
	smp_ops.smp_prepare_cpus(max_cpus);
}

static inline void smp_cpus_done(unsigned int max_cpus)
{
	smp_ops.smp_cpus_done(max_cpus);
}

static inline int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
	return smp_ops.cpu_up(cpu, tidle);
}

static inline int __cpu_disable(void)
{
	return smp_ops.cpu_disable();
}

static inline void __cpu_die(unsigned int cpu)
{
	smp_ops.cpu_die(cpu);
}

static inline void play_dead(void)
{
	smp_ops.play_dead();
}

static inline void smp_send_reschedule(int cpu)
{
	smp_ops.smp_send_reschedule(cpu);
}

static inline void arch_send_call_function_single_ipi(int cpu)
{
	smp_ops.send_call_func_single_ipi(cpu);
}

static inline void arch_send_call_function_ipi_mask(const struct cpumask *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);
void common_cpu_up(unsigned int cpunum, struct task_struct *tidle);
int native_cpu_up(unsigned int cpunum, struct task_struct *tidle);
int native_cpu_disable(void);
int common_cpu_die(unsigned int cpu);
void native_cpu_die(unsigned int cpu);
void native_play_dead(void);
void play_dead_common(void);
void wbinvd_on_cpu(int cpu);
int wbinvd_on_all_cpus(void);

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)

#else /* !CONFIG_SMP */
#define wbinvd_on_cpu(cpu)     wbinvd()
static inline int wbinvd_on_all_cpus(void)
{
	wbinvd();
	return 0;
}
#endif /* CONFIG_SMP */

extern unsigned disabled_cpus;

#ifdef CONFIG_X86_32_SMP
/*
 * This function is needed by all SMP systems. It must _always_ be valid
 * from the initial startup. We map APIC_BASE very early in page_setup(),
 * so this is correct in the x86 case.
 */
#define raw_smp_processor_id() (this_cpu_read(cpu_number))
extern int safe_smp_processor_id(void);

#elif defined(CONFIG_X86_64_SMP)
#define raw_smp_processor_id() (this_cpu_read(cpu_number))

#define stack_smp_processor_id()					\
({								\
	struct thread_info *ti;						\
	__asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (CURRENT_MASK));	\
	ti->cpu;							\
})
#define safe_smp_processor_id()		smp_processor_id()

#endif

#ifdef CONFIG_X86_LOCAL_APIC

#ifndef CONFIG_X86_64
static inline int logical_smp_processor_id(void)
{
	/* we don't want to mark this access volatile - bad code generation */
	return GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
}

#endif

extern int hard_smp_processor_id(void);

#else /* CONFIG_X86_LOCAL_APIC */

# ifndef CONFIG_SMP
#  define hard_smp_processor_id()	0
# endif

#endif /* CONFIG_X86_LOCAL_APIC */

#ifdef CONFIG_DEBUG_NMI_SELFTEST
extern void nmi_selftest(void);
#else
#define nmi_selftest() do { } while (0)
#endif

#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_SMP_H */