LXR linux/include/linux/cpu.h

   1/*
   2 * include/linux/cpu.h - generic cpu definition
   3 *
   4 * This is mainly for topological representation. We define the 
   5 * basic 'struct cpu' here, which can be embedded in per-arch 
   6 * definitions of processors.
   7 *
   8 * Basic handling of the devices is done in drivers/base/cpu.c
   9 * and system devices are handled in drivers/base/sys.c. 
  10 *
  11 * CPUs are exported via sysfs in the class/cpu/devices/
  12 * directory. 
  13 */
  14#ifndef _LINUX_CPU_H_
  15#define _LINUX_CPU_H_
  16
  17#include <linux/sysdev.h>
  18#include <linux/node.h>
  19#include <linux/compiler.h>
  20#include <linux/cpumask.h>
  21
  22struct cpu {
  23        int node_id;            /* The node which contains the CPU */
  24        int hotpluggable;       /* creates sysfs control file if hotpluggable */
  25        struct sys_device sysdev;
  26};
  27
  28extern int register_cpu(struct cpu *cpu, int num);
  29extern struct sys_device *get_cpu_sysdev(unsigned cpu);
  30
  31extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
  32extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
  33
  34extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
  35extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
  36
  37extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  38
  39#ifdef CONFIG_HOTPLUG_CPU
  40extern void unregister_cpu(struct cpu *cpu);
  41extern ssize_t arch_cpu_probe(const char *, size_t);
  42extern ssize_t arch_cpu_release(const char *, size_t);
  43#endif
  44struct notifier_block;
  45
  46/*
  47 * CPU notifier priorities.
  48 */
  49enum {
  50        /*
  51         * SCHED_ACTIVE marks a cpu which is coming up active during
  52         * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  53         * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  54         * cpu_active mask right after SCHED_ACTIVE.  During
  55         * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  56         * ordered in the similar way.
  57         *
  58         * This ordering guarantees consistent cpu_active mask and
  59         * migration behavior to all cpu notifiers.
  60         */
  61        CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  62        CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  63        CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  64        CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  65
  66        /* migration should happen before other stuff but after perf */
  67        CPU_PRI_PERF            = 20,
  68        CPU_PRI_MIGRATION       = 10,
  69        /* prepare workqueues for other notifiers */
  70        CPU_PRI_WORKQUEUE       = 5,
  71};
  72
  73#ifdef CONFIG_SMP
  74/* Need to know about CPUs going up/down? */
  75#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
  76#define cpu_notifier(fn, pri) {                                 \
  77        static struct notifier_block fn##_nb __cpuinitdata =    \
  78                { .notifier_call = fn, .priority = pri };       \
  79        register_cpu_notifier(&fn##_nb);                        \
  80}
  81#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  82#define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
  83#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  84#ifdef CONFIG_HOTPLUG_CPU
  85extern int register_cpu_notifier(struct notifier_block *nb);
  86extern void unregister_cpu_notifier(struct notifier_block *nb);
  87#else
  88
  89#ifndef MODULE
  90extern int register_cpu_notifier(struct notifier_block *nb);
  91#else
  92static inline int register_cpu_notifier(struct notifier_block *nb)
  93{
  94        return 0;
  95}
  96#endif
  97
  98static inline void unregister_cpu_notifier(struct notifier_block *nb)
  99{
 100}
 101#endif
 102
 103int cpu_up(unsigned int cpu);
 104void notify_cpu_starting(unsigned int cpu);
 105extern void cpu_maps_update_begin(void);
 106extern void cpu_maps_update_done(void);
 107
 108#else   /* CONFIG_SMP */
 109
 110#define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 111
 112static inline int register_cpu_notifier(struct notifier_block *nb)
 113{
 114        return 0;
 115}
 116
 117static inline void unregister_cpu_notifier(struct notifier_block *nb)
 118{
 119}
 120
 121static inline void cpu_maps_update_begin(void)
 122{
 123}
 124
 125static inline void cpu_maps_update_done(void)
 126{
 127}
 128
 129#endif /* CONFIG_SMP */
 130extern struct sysdev_class cpu_sysdev_class;
 131
 132#ifdef CONFIG_HOTPLUG_CPU
 133/* Stop CPUs going up and down. */
 134
 135extern void get_online_cpus(void);
 136extern void put_online_cpus(void);
 137#define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 138#define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 139#define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 140int cpu_down(unsigned int cpu);
 141
 142#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 143extern void cpu_hotplug_driver_lock(void);
 144extern void cpu_hotplug_driver_unlock(void);
 145#else
 146static inline void cpu_hotplug_driver_lock(void)
 147{
 148}
 149
 150static inline void cpu_hotplug_driver_unlock(void)
 151{
 152}
 153#endif
 154
 155#else           /* CONFIG_HOTPLUG_CPU */
 156
 157#define get_online_cpus()       do { } while (0)
 158#define put_online_cpus()       do { } while (0)
 159#define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 160/* These aren't inline functions due to a GCC bug. */
 161#define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 162#define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 163#endif          /* CONFIG_HOTPLUG_CPU */
 164
 165#ifdef CONFIG_PM_SLEEP_SMP
 166extern int suspend_cpu_hotplug;
 167
 168extern int disable_nonboot_cpus(void);
 169extern void enable_nonboot_cpus(void);
 170#else /* !CONFIG_PM_SLEEP_SMP */
 171#define suspend_cpu_hotplug     0
 172
 173static inline int disable_nonboot_cpus(void) { return 0; }
 174static inline void enable_nonboot_cpus(void) {}
 175#endif /* !CONFIG_PM_SLEEP_SMP */
 176
 177#endif /* _LINUX_CPU_H_ */
 178