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 struct device_node;
  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 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
  33 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
  34                                               int cpu, unsigned int *thread);
  35
  36 extern int cpu_add_dev_attr(struct device_attribute *attr);
  37 extern void cpu_remove_dev_attr(struct device_attribute *attr);
  38
  39 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  40 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  41
  42 #ifdef CONFIG_HOTPLUG_CPU
  43 extern void unregister_cpu(struct cpu *cpu);
  44 extern ssize_t arch_cpu_probe(const char *, size_t);
  45 extern ssize_t arch_cpu_release(const char *, size_t);
  46 #endif
  47 struct notifier_block;
  48
  49 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
  50 extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
  51 extern ssize_t arch_print_cpu_modalias(struct device *dev,
  52                                        struct device_attribute *attr,
  53                                        char *bufptr);
  54 #endif
  55
  56 /*
  57  * CPU notifier priorities.
  58  */
  59 enum {
  60         /*
  61          * SCHED_ACTIVE marks a cpu which is coming up active during
  62          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  63          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  64          * cpu_active mask right after SCHED_ACTIVE.  During
  65          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  66          * ordered in the similar way.
  67          *
  68          * This ordering guarantees consistent cpu_active mask and
  69          * migration behavior to all cpu notifiers.
  70          */
  71         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  72         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  73         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  74         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  75
  76         /* migration should happen before other stuff but after perf */
  77         CPU_PRI_PERF            = 20,
  78         CPU_PRI_MIGRATION       = 10,
  79         /* bring up workqueues before normal notifiers and down after */
  80         CPU_PRI_WORKQUEUE_UP    = 5,
  81         CPU_PRI_WORKQUEUE_DOWN  = -5,
  82 };
  83
  84 #define CPU_ONLINE              0x0002 /* CPU (unsigned)v is up */
  85 #define CPU_UP_PREPARE          0x0003 /* CPU (unsigned)v coming up */
  86 #define CPU_UP_CANCELED         0x0004 /* CPU (unsigned)v NOT coming up */
  87 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
  88 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
  89 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
  90 #define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
  91                                         * not handling interrupts, soon dead.
  92                                         * Called on the dying cpu, interrupts
  93                                         * are already disabled. Must not
  94                                         * sleep, must not fail */
  95 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  96                                         * lock is dropped */
  97 #define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
  98                                         * Called on the new cpu, just before
  99                                         * enabling interrupts. Must not sleep,
 100                                         * must not fail */
 101
 102 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
 103  * operation in progress
 104  */
 105 #define CPU_TASKS_FROZEN        0x0010
 106
 107 #define CPU_ONLINE_FROZEN       (CPU_ONLINE | CPU_TASKS_FROZEN)
 108 #define CPU_UP_PREPARE_FROZEN   (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
 109 #define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
 110 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 111 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 112 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
 113 #define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
 114 #define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
 115
 116
 117 #ifdef CONFIG_SMP
 118 /* Need to know about CPUs going up/down? */
 119 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
 120 #define cpu_notifier(fn, pri) {                                 \
 121         static struct notifier_block fn##_nb =                  \
 122                 { .notifier_call = fn, .priority = pri };       \
 123         register_cpu_notifier(&fn##_nb);                        \
 124 }
 125 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 126 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 127 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 128 #ifdef CONFIG_HOTPLUG_CPU
 129 extern int register_cpu_notifier(struct notifier_block *nb);
 130 extern void unregister_cpu_notifier(struct notifier_block *nb);
 131 #else
 132
 133 #ifndef MODULE
 134 extern int register_cpu_notifier(struct notifier_block *nb);
 135 #else
 136 static inline int register_cpu_notifier(struct notifier_block *nb)
 137 {
 138         return 0;
 139 }
 140 #endif
 141
 142 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 143 {
 144 }
 145 #endif
 146
 147 int cpu_up(unsigned int cpu);
 148 void notify_cpu_starting(unsigned int cpu);
 149 extern void cpu_maps_update_begin(void);
 150 extern void cpu_maps_update_done(void);
 151
 152 #else   /* CONFIG_SMP */
 153
 154 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 155
 156 static inline int register_cpu_notifier(struct notifier_block *nb)
 157 {
 158         return 0;
 159 }
 160
 161 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 162 {
 163 }
 164
 165 static inline void cpu_maps_update_begin(void)
 166 {
 167 }
 168
 169 static inline void cpu_maps_update_done(void)
 170 {
 171 }
 172
 173 #endif /* CONFIG_SMP */
 174 extern struct bus_type cpu_subsys;
 175
 176 #ifdef CONFIG_HOTPLUG_CPU
 177 /* Stop CPUs going up and down. */
 178
 179 extern void cpu_hotplug_begin(void);
 180 extern void cpu_hotplug_done(void);
 181 extern void get_online_cpus(void);
 182 extern void put_online_cpus(void);
 183 extern void cpu_hotplug_disable(void);
 184 extern void cpu_hotplug_enable(void);
 185 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 186 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 187 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 188 void clear_tasks_mm_cpumask(int cpu);
 189 int cpu_down(unsigned int cpu);
 190
 191 #else           /* CONFIG_HOTPLUG_CPU */
 192
 193 static inline void cpu_hotplug_begin(void) {}
 194 static inline void cpu_hotplug_done(void) {}
 195 #define get_online_cpus()       do { } while (0)
 196 #define put_online_cpus()       do { } while (0)
 197 #define cpu_hotplug_disable()   do { } while (0)
 198 #define cpu_hotplug_enable()    do { } while (0)
 199 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 200 /* These aren't inline functions due to a GCC bug. */
 201 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 202 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 203 #endif          /* CONFIG_HOTPLUG_CPU */
 204
 205 #ifdef CONFIG_PM_SLEEP_SMP
 206 extern int disable_nonboot_cpus(void);
 207 extern void enable_nonboot_cpus(void);
 208 #else /* !CONFIG_PM_SLEEP_SMP */
 209 static inline int disable_nonboot_cpus(void) { return 0; }
 210 static inline void enable_nonboot_cpus(void) {}
 211 #endif /* !CONFIG_PM_SLEEP_SMP */
 212
 213 enum cpuhp_state {
 214         CPUHP_OFFLINE,
 215         CPUHP_ONLINE,
 216 };
 217
 218 void cpu_startup_entry(enum cpuhp_state state);
 219 void cpu_idle(void);
 220
 221 void cpu_idle_poll_ctrl(bool enable);
 222
 223 void arch_cpu_idle(void);
 224 void arch_cpu_idle_prepare(void);
 225 void arch_cpu_idle_enter(void);
 226 void arch_cpu_idle_exit(void);
 227 void arch_cpu_idle_dead(void);
 228
 229 #endif /* _LINUX_CPU_H_ */