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 /*
  50  * CPU notifier priorities.
  51  */
  52 enum {
  53         /*
  54          * SCHED_ACTIVE marks a cpu which is coming up active during
  55          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  56          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  57          * cpu_active mask right after SCHED_ACTIVE.  During
  58          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  59          * ordered in the similar way.
  60          *
  61          * This ordering guarantees consistent cpu_active mask and
  62          * migration behavior to all cpu notifiers.
  63          */
  64         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  65         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  66         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  67         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  68
  69         /* migration should happen before other stuff but after perf */
  70         CPU_PRI_PERF            = 20,
  71         CPU_PRI_MIGRATION       = 10,
  72         /* bring up workqueues before normal notifiers and down after */
  73         CPU_PRI_WORKQUEUE_UP    = 5,
  74         CPU_PRI_WORKQUEUE_DOWN  = -5,
  75 };
  76
  77 #define CPU_ONLINE              0x0002 /* CPU (unsigned)v is up */
  78 #define CPU_UP_PREPARE          0x0003 /* CPU (unsigned)v coming up */
  79 #define CPU_UP_CANCELED         0x0004 /* CPU (unsigned)v NOT coming up */
  80 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
  81 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
  82 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
  83 #define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
  84                                         * not handling interrupts, soon dead.
  85                                         * Called on the dying cpu, interrupts
  86                                         * are already disabled. Must not
  87                                         * sleep, must not fail */
  88 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  89                                         * lock is dropped */
  90 #define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
  91                                         * Called on the new cpu, just before
  92                                         * enabling interrupts. Must not sleep,
  93                                         * must not fail */
  94
  95 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
  96  * operation in progress
  97  */
  98 #define CPU_TASKS_FROZEN        0x0010
  99
 100 #define CPU_ONLINE_FROZEN       (CPU_ONLINE | CPU_TASKS_FROZEN)
 101 #define CPU_UP_PREPARE_FROZEN   (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
 102 #define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
 103 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 104 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 105 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
 106 #define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
 107 #define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
 108
 109
 110 #ifdef CONFIG_SMP
 111 /* Need to know about CPUs going up/down? */
 112 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
 113 #define cpu_notifier(fn, pri) {                                 \
 114         static struct notifier_block fn##_nb =                  \
 115                 { .notifier_call = fn, .priority = pri };       \
 116         register_cpu_notifier(&fn##_nb);                        \
 117 }
 118
 119 #define __cpu_notifier(fn, pri) {                               \
 120         static struct notifier_block fn##_nb =                  \
 121                 { .notifier_call = fn, .priority = pri };       \
 122         __register_cpu_notifier(&fn##_nb);                      \
 123 }
 124 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 125 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 126 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
 127 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 128
 129 #ifdef CONFIG_HOTPLUG_CPU
 130 extern int register_cpu_notifier(struct notifier_block *nb);
 131 extern int __register_cpu_notifier(struct notifier_block *nb);
 132 extern void unregister_cpu_notifier(struct notifier_block *nb);
 133 extern void __unregister_cpu_notifier(struct notifier_block *nb);
 134 #else
 135
 136 #ifndef MODULE
 137 extern int register_cpu_notifier(struct notifier_block *nb);
 138 extern int __register_cpu_notifier(struct notifier_block *nb);
 139 #else
 140 static inline int register_cpu_notifier(struct notifier_block *nb)
 141 {
 142         return 0;
 143 }
 144
 145 static inline int __register_cpu_notifier(struct notifier_block *nb)
 146 {
 147         return 0;
 148 }
 149 #endif
 150
 151 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 152 {
 153 }
 154
 155 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
 156 {
 157 }
 158 #endif
 159
 160 int cpu_up(unsigned int cpu);
 161 void notify_cpu_starting(unsigned int cpu);
 162 extern void cpu_maps_update_begin(void);
 163 extern void cpu_maps_update_done(void);
 164
 165 #define cpu_notifier_register_begin     cpu_maps_update_begin
 166 #define cpu_notifier_register_done      cpu_maps_update_done
 167
 168 #else   /* CONFIG_SMP */
 169
 170 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 171 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
 172
 173 static inline int register_cpu_notifier(struct notifier_block *nb)
 174 {
 175         return 0;
 176 }
 177
 178 static inline int __register_cpu_notifier(struct notifier_block *nb)
 179 {
 180         return 0;
 181 }
 182
 183 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 184 {
 185 }
 186
 187 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
 188 {
 189 }
 190
 191 static inline void cpu_maps_update_begin(void)
 192 {
 193 }
 194
 195 static inline void cpu_maps_update_done(void)
 196 {
 197 }
 198
 199 static inline void cpu_notifier_register_begin(void)
 200 {
 201 }
 202
 203 static inline void cpu_notifier_register_done(void)
 204 {
 205 }
 206
 207 #endif /* CONFIG_SMP */
 208 extern struct bus_type cpu_subsys;
 209
 210 #ifdef CONFIG_HOTPLUG_CPU
 211 /* Stop CPUs going up and down. */
 212
 213 extern void cpu_hotplug_begin(void);
 214 extern void cpu_hotplug_done(void);
 215 extern void get_online_cpus(void);
 216 extern void put_online_cpus(void);
 217 extern void cpu_hotplug_disable(void);
 218 extern void cpu_hotplug_enable(void);
 219 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 220 #define __hotcpu_notifier(fn, pri)      __cpu_notifier(fn, pri)
 221 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 222 #define __register_hotcpu_notifier(nb)  __register_cpu_notifier(nb)
 223 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 224 #define __unregister_hotcpu_notifier(nb)        __unregister_cpu_notifier(nb)
 225 void clear_tasks_mm_cpumask(int cpu);
 226 int cpu_down(unsigned int cpu);
 227
 228 #else           /* CONFIG_HOTPLUG_CPU */
 229
 230 static inline void cpu_hotplug_begin(void) {}
 231 static inline void cpu_hotplug_done(void) {}
 232 #define get_online_cpus()       do { } while (0)
 233 #define put_online_cpus()       do { } while (0)
 234 #define cpu_hotplug_disable()   do { } while (0)
 235 #define cpu_hotplug_enable()    do { } while (0)
 236 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 237 #define __hotcpu_notifier(fn, pri)      do { (void)(fn); } while (0)
 238 /* These aren't inline functions due to a GCC bug. */
 239 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 240 #define __register_hotcpu_notifier(nb)  ({ (void)(nb); 0; })
 241 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 242 #define __unregister_hotcpu_notifier(nb)        ({ (void)(nb); })
 243 #endif          /* CONFIG_HOTPLUG_CPU */
 244
 245 #ifdef CONFIG_PM_SLEEP_SMP
 246 extern int disable_nonboot_cpus(void);
 247 extern void enable_nonboot_cpus(void);
 248 #else /* !CONFIG_PM_SLEEP_SMP */
 249 static inline int disable_nonboot_cpus(void) { return 0; }
 250 static inline void enable_nonboot_cpus(void) {}
 251 #endif /* !CONFIG_PM_SLEEP_SMP */
 252
 253 enum cpuhp_state {
 254         CPUHP_OFFLINE,
 255         CPUHP_ONLINE,
 256 };
 257
 258 void cpu_startup_entry(enum cpuhp_state state);
 259 void cpu_idle(void);
 260
 261 void cpu_idle_poll_ctrl(bool enable);
 262
 263 void arch_cpu_idle(void);
 264 void arch_cpu_idle_prepare(void);
 265 void arch_cpu_idle_enter(void);
 266 void arch_cpu_idle_exit(void);
 267 void arch_cpu_idle_dead(void);
 268
 269 #endif /* _LINUX_CPU_H_ */