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
  20 struct device;
  21
  22 struct 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
  28 extern int register_cpu(struct cpu *cpu, int num);
  29 extern struct device *get_cpu_device(unsigned cpu);
  30 extern bool cpu_is_hotpluggable(unsigned cpu);
  31
  32 extern int cpu_add_dev_attr(struct device_attribute *attr);
  33 extern void cpu_remove_dev_attr(struct device_attribute *attr);
  34
  35 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  36 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  37
  38 #ifdef CONFIG_HOTPLUG_CPU
  39 extern void unregister_cpu(struct cpu *cpu);
  40 extern ssize_t arch_cpu_probe(const char *, size_t);
  41 extern ssize_t arch_cpu_release(const char *, size_t);
  42 #endif
  43 struct notifier_block;
  44
  45 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
  46 extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
  47 extern 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  */
  55 enum {
  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
 125 extern int register_cpu_notifier(struct notifier_block *nb);
 126 extern void unregister_cpu_notifier(struct notifier_block *nb);
 127 #else
 128
 129 #ifndef MODULE
 130 extern int register_cpu_notifier(struct notifier_block *nb);
 131 #else
 132 static inline int register_cpu_notifier(struct notifier_block *nb)
 133 {
 134         return 0;
 135 }
 136 #endif
 137
 138 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 139 {
 140 }
 141 #endif
 142
 143 int cpu_up(unsigned int cpu);
 144 void notify_cpu_starting(unsigned int cpu);
 145 extern void cpu_maps_update_begin(void);
 146 extern void cpu_maps_update_done(void);
 147
 148 #else   /* CONFIG_SMP */
 149
 150 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 151
 152 static inline int register_cpu_notifier(struct notifier_block *nb)
 153 {
 154         return 0;
 155 }
 156
 157 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 158 {
 159 }
 160
 161 static inline void cpu_maps_update_begin(void)
 162 {
 163 }
 164
 165 static inline void cpu_maps_update_done(void)
 166 {
 167 }
 168
 169 #endif /* CONFIG_SMP */
 170 extern struct bus_type cpu_subsys;
 171
 172 #ifdef CONFIG_HOTPLUG_CPU
 173 /* Stop CPUs going up and down. */
 174
 175 extern void get_online_cpus(void);
 176 extern void put_online_cpus(void);
 177 extern void cpu_hotplug_disable(void);
 178 extern 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)
 182 void clear_tasks_mm_cpumask(int cpu);
 183 int cpu_down(unsigned int cpu);
 184
 185 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 186 extern void cpu_hotplug_driver_lock(void);
 187 extern void cpu_hotplug_driver_unlock(void);
 188 #else
 189 static inline void cpu_hotplug_driver_lock(void)
 190 {
 191 }
 192
 193 static 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
 211 extern int disable_nonboot_cpus(void);
 212 extern void enable_nonboot_cpus(void);
 213 #else /* !CONFIG_PM_SLEEP_SMP */
 214 static inline int disable_nonboot_cpus(void) { return 0; }
 215 static inline void enable_nonboot_cpus(void) {}
 216 #endif /* !CONFIG_PM_SLEEP_SMP */
 217
 218 enum cpuhp_state {
 219         CPUHP_OFFLINE,
 220         CPUHP_ONLINE,
 221 };
 222
 223 void cpu_startup_entry(enum cpuhp_state state);
 224 void cpu_idle(void);
 225
 226 void cpu_idle_poll_ctrl(bool enable);
 227
 228 void arch_cpu_idle(void);
 229 void arch_cpu_idle_prepare(void);
 230 void arch_cpu_idle_enter(void);
 231 void arch_cpu_idle_exit(void);
 232 void arch_cpu_idle_dead(void);
 233
 234 #endif /* _LINUX_CPU_H_ */