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