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 *
  10 * CPUs are exported via sysfs in the devices/system/cpu
  11 * directory. 
  12 */
  13#ifndef _LINUX_CPU_H_
  14#define _LINUX_CPU_H_
  15
  16#include <linux/node.h>
  17#include <linux/compiler.h>
  18#include <linux/cpumask.h>
  19
  20struct device;
  21
  22struct cpu {
  23        int node_id;            /* The node which contains the CPU */
  24        int hotpluggable;       /* creates sysfs control file if hotpluggable */
  25        struct device dev;
  26};
  27
  28extern int register_cpu(struct cpu *cpu, int num);
  29extern struct device *get_cpu_device(unsigned cpu);
  30extern bool cpu_is_hotpluggable(unsigned cpu);
  31
  32extern int cpu_add_dev_attr(struct device_attribute *attr);
  33extern void cpu_remove_dev_attr(struct device_attribute *attr);
  34
  35extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  36extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  37
  38#ifdef CONFIG_HOTPLUG_CPU
  39extern void unregister_cpu(struct cpu *cpu);
  40extern ssize_t arch_cpu_probe(const char *, size_t);
  41extern ssize_t arch_cpu_release(const char *, size_t);
  42#endif
  43struct notifier_block;
  44
  45#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
  46extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
  47extern ssize_t arch_print_cpu_modalias(struct device *dev,
  48                                       struct device_attribute *attr,
  49                                       char *bufptr);
  50#endif
  51
  52/*
  53 * CPU notifier priorities.
  54 */
  55enum {
  56        /*
  57         * SCHED_ACTIVE marks a cpu which is coming up active during
  58         * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  59         * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  60         * cpu_active mask right after SCHED_ACTIVE.  During
  61         * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  62         * ordered in the similar way.
  63         *
  64         * This ordering guarantees consistent cpu_active mask and
  65         * migration behavior to all cpu notifiers.
  66         */
  67        CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  68        CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  69        CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  70        CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  71
  72        /* migration should happen before other stuff but after perf */
  73        CPU_PRI_PERF            = 20,
  74        CPU_PRI_MIGRATION       = 10,
  75        /* bring up workqueues before normal notifiers and down after */
  76        CPU_PRI_WORKQUEUE_UP    = 5,
  77        CPU_PRI_WORKQUEUE_DOWN  = -5,
  78};
  79
  80#define CPU_ONLINE              0x0002 /* CPU (unsigned)v is up */
  81#define CPU_UP_PREPARE          0x0003 /* CPU (unsigned)v coming up */
  82#define CPU_UP_CANCELED         0x0004 /* CPU (unsigned)v NOT coming up */
  83#define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
  84#define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
  85#define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
  86#define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
  87                                        * not handling interrupts, soon dead.
  88                                        * Called on the dying cpu, interrupts
  89                                        * are already disabled. Must not
  90                                        * sleep, must not fail */
  91#define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  92                                        * lock is dropped */
  93#define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
  94                                        * Called on the new cpu, just before
  95                                        * enabling interrupts. Must not sleep,
  96                                        * must not fail */
  97
  98/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
  99 * operation in progress
 100 */
 101#define CPU_TASKS_FROZEN        0x0010
 102
 103#define CPU_ONLINE_FROZEN       (CPU_ONLINE | CPU_TASKS_FROZEN)
 104#define CPU_UP_PREPARE_FROZEN   (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
 105#define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
 106#define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 107#define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 108#define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
 109#define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
 110#define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
 111
 112
 113#ifdef CONFIG_SMP
 114/* Need to know about CPUs going up/down? */
 115#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
 116#define cpu_notifier(fn, pri) {                                 \
 117        static struct notifier_block fn##_nb =                  \
 118                { .notifier_call = fn, .priority = pri };       \
 119        register_cpu_notifier(&fn##_nb);                        \
 120}
 121#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 122#define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 123#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 124#ifdef CONFIG_HOTPLUG_CPU
 125extern int register_cpu_notifier(struct notifier_block *nb);
 126extern void unregister_cpu_notifier(struct notifier_block *nb);
 127#else
 128
 129#ifndef MODULE
 130extern int register_cpu_notifier(struct notifier_block *nb);
 131#else
 132static inline int register_cpu_notifier(struct notifier_block *nb)
 133{
 134        return 0;
 135}
 136#endif
 137
 138static inline void unregister_cpu_notifier(struct notifier_block *nb)
 139{
 140}
 141#endif
 142
 143int cpu_up(unsigned int cpu);
 144void notify_cpu_starting(unsigned int cpu);
 145extern void cpu_maps_update_begin(void);
 146extern void cpu_maps_update_done(void);
 147
 148#else   /* CONFIG_SMP */
 149
 150#define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 151
 152static inline int register_cpu_notifier(struct notifier_block *nb)
 153{
 154        return 0;
 155}
 156
 157static inline void unregister_cpu_notifier(struct notifier_block *nb)
 158{
 159}
 160
 161static inline void cpu_maps_update_begin(void)
 162{
 163}
 164
 165static inline void cpu_maps_update_done(void)
 166{
 167}
 168
 169#endif /* CONFIG_SMP */
 170extern struct bus_type cpu_subsys;
 171
 172#ifdef CONFIG_HOTPLUG_CPU
 173/* Stop CPUs going up and down. */
 174
 175extern void get_online_cpus(void);
 176extern void put_online_cpus(void);
 177extern void cpu_hotplug_disable(void);
 178extern void cpu_hotplug_enable(void);
 179#define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 180#define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 181#define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 182void clear_tasks_mm_cpumask(int cpu);
 183int cpu_down(unsigned int cpu);
 184
 185#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 186extern void cpu_hotplug_driver_lock(void);
 187extern void cpu_hotplug_driver_unlock(void);
 188#else
 189static inline void cpu_hotplug_driver_lock(void)
 190{
 191}
 192
 193static inline void cpu_hotplug_driver_unlock(void)
 194{
 195}
 196#endif
 197
 198#else           /* CONFIG_HOTPLUG_CPU */
 199
 200#define get_online_cpus()       do { } while (0)
 201#define put_online_cpus()       do { } while (0)
 202#define cpu_hotplug_disable()   do { } while (0)
 203#define cpu_hotplug_enable()    do { } while (0)
 204#define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 205/* These aren't inline functions due to a GCC bug. */
 206#define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 207#define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 208#endif          /* CONFIG_HOTPLUG_CPU */
 209
 210#ifdef CONFIG_PM_SLEEP_SMP
 211extern int disable_nonboot_cpus(void);
 212extern void enable_nonboot_cpus(void);
 213#else /* !CONFIG_PM_SLEEP_SMP */
 214static inline int disable_nonboot_cpus(void) { return 0; }
 215static inline void enable_nonboot_cpus(void) {}
 216#endif /* !CONFIG_PM_SLEEP_SMP */
 217
 218enum cpuhp_state {
 219        CPUHP_OFFLINE,
 220        CPUHP_ONLINE,
 221};
 222
 223void cpu_startup_entry(enum cpuhp_state state);
 224void cpu_idle(void);
 225
 226void cpu_idle_poll_ctrl(bool enable);
 227
 228void arch_cpu_idle(void);
 229void arch_cpu_idle_prepare(void);
 230void arch_cpu_idle_enter(void);
 231void arch_cpu_idle_exit(void);
 232void arch_cpu_idle_dead(void);
 233
 234#endif /* _LINUX_CPU_H_ */
 235