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 struct attribute_group;
  23
  24 struct cpu {
  25         int node_id;            /* The node which contains the CPU */
  26         int hotpluggable;       /* creates sysfs control file if hotpluggable */
  27         struct device dev;
  28 };
  29
  30 extern int register_cpu(struct cpu *cpu, int num);
  31 extern struct device *get_cpu_device(unsigned cpu);
  32 extern bool cpu_is_hotpluggable(unsigned cpu);
  33 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
  34 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
  35                                               int cpu, unsigned int *thread);
  36
  37 extern int cpu_add_dev_attr(struct device_attribute *attr);
  38 extern void cpu_remove_dev_attr(struct device_attribute *attr);
  39
  40 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  41 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  42
  43 extern __printf(4, 5)
  44 struct device *cpu_device_create(struct device *parent, void *drvdata,
  45                                  const struct attribute_group **groups,
  46                                  const char *fmt, ...);
  47 #ifdef CONFIG_HOTPLUG_CPU
  48 extern void unregister_cpu(struct cpu *cpu);
  49 extern ssize_t arch_cpu_probe(const char *, size_t);
  50 extern ssize_t arch_cpu_release(const char *, size_t);
  51 #endif
  52 struct notifier_block;
  53
  54 /*
  55  * CPU notifier priorities.
  56  */
  57 enum {
  58         /*
  59          * SCHED_ACTIVE marks a cpu which is coming up active during
  60          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  61          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  62          * cpu_active mask right after SCHED_ACTIVE.  During
  63          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  64          * ordered in the similar way.
  65          *
  66          * This ordering guarantees consistent cpu_active mask and
  67          * migration behavior to all cpu notifiers.
  68          */
  69         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  70         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  71         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  72         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  73
  74         /* migration should happen before other stuff but after perf */
  75         CPU_PRI_PERF            = 20,
  76         CPU_PRI_MIGRATION       = 10,
  77         CPU_PRI_SMPBOOT         = 9,
  78         /* bring up workqueues before normal notifiers and down after */
  79         CPU_PRI_WORKQUEUE_UP    = 5,
  80         CPU_PRI_WORKQUEUE_DOWN  = -5,
  81 };
  82
  83 #define CPU_ONLINE              0x0002 /* CPU (unsigned)v is up */
  84 #define CPU_UP_PREPARE          0x0003 /* CPU (unsigned)v coming up */
  85 #define CPU_UP_CANCELED         0x0004 /* CPU (unsigned)v NOT coming up */
  86 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
  87 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
  88 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
  89 #define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
  90                                         * not handling interrupts, soon dead.
  91                                         * Called on the dying cpu, interrupts
  92                                         * are already disabled. Must not
  93                                         * sleep, must not fail */
  94 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  95                                         * lock is dropped */
  96 #define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
  97                                         * Called on the new cpu, just before
  98                                         * enabling interrupts. Must not sleep,
  99                                         * must not fail */
 100 #define CPU_DYING_IDLE          0x000B /* CPU (unsigned)v dying, reached
 101                                         * idle loop. */
 102 #define CPU_BROKEN              0x000C /* CPU (unsigned)v did not die properly,
 103                                         * perhaps due to preemption. */
 104
 105 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
 106  * operation in progress
 107  */
 108 #define CPU_TASKS_FROZEN        0x0010
 109
 110 #define CPU_ONLINE_FROZEN       (CPU_ONLINE | CPU_TASKS_FROZEN)
 111 #define CPU_UP_PREPARE_FROZEN   (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
 112 #define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
 113 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 114 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 115 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
 116 #define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
 117 #define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
 118
 119
 120 #ifdef CONFIG_SMP
 121 /* Need to know about CPUs going up/down? */
 122 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
 123 #define cpu_notifier(fn, pri) {                                 \
 124         static struct notifier_block fn##_nb =                  \
 125                 { .notifier_call = fn, .priority = pri };       \
 126         register_cpu_notifier(&fn##_nb);                        \
 127 }
 128
 129 #define __cpu_notifier(fn, pri) {                               \
 130         static struct notifier_block fn##_nb =                  \
 131                 { .notifier_call = fn, .priority = pri };       \
 132         __register_cpu_notifier(&fn##_nb);                      \
 133 }
 134 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 135 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 136 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
 137 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 138
 139 #ifdef CONFIG_HOTPLUG_CPU
 140 extern int register_cpu_notifier(struct notifier_block *nb);
 141 extern int __register_cpu_notifier(struct notifier_block *nb);
 142 extern void unregister_cpu_notifier(struct notifier_block *nb);
 143 extern void __unregister_cpu_notifier(struct notifier_block *nb);
 144 #else
 145
 146 #ifndef MODULE
 147 extern int register_cpu_notifier(struct notifier_block *nb);
 148 extern int __register_cpu_notifier(struct notifier_block *nb);
 149 #else
 150 static inline int register_cpu_notifier(struct notifier_block *nb)
 151 {
 152         return 0;
 153 }
 154
 155 static inline int __register_cpu_notifier(struct notifier_block *nb)
 156 {
 157         return 0;
 158 }
 159 #endif
 160
 161 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 162 {
 163 }
 164
 165 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
 166 {
 167 }
 168 #endif
 169
 170 void smpboot_thread_init(void);
 171 int cpu_up(unsigned int cpu);
 172 void notify_cpu_starting(unsigned int cpu);
 173 extern void cpu_maps_update_begin(void);
 174 extern void cpu_maps_update_done(void);
 175
 176 #define cpu_notifier_register_begin     cpu_maps_update_begin
 177 #define cpu_notifier_register_done      cpu_maps_update_done
 178
 179 #else   /* CONFIG_SMP */
 180
 181 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 182 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
 183
 184 static inline int register_cpu_notifier(struct notifier_block *nb)
 185 {
 186         return 0;
 187 }
 188
 189 static inline int __register_cpu_notifier(struct notifier_block *nb)
 190 {
 191         return 0;
 192 }
 193
 194 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 195 {
 196 }
 197
 198 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
 199 {
 200 }
 201
 202 static inline void cpu_maps_update_begin(void)
 203 {
 204 }
 205
 206 static inline void cpu_maps_update_done(void)
 207 {
 208 }
 209
 210 static inline void cpu_notifier_register_begin(void)
 211 {
 212 }
 213
 214 static inline void cpu_notifier_register_done(void)
 215 {
 216 }
 217
 218 static inline void smpboot_thread_init(void)
 219 {
 220 }
 221
 222 #endif /* CONFIG_SMP */
 223 extern struct bus_type cpu_subsys;
 224
 225 #ifdef CONFIG_HOTPLUG_CPU
 226 /* Stop CPUs going up and down. */
 227
 228 extern void cpu_hotplug_begin(void);
 229 extern void cpu_hotplug_done(void);
 230 extern void get_online_cpus(void);
 231 extern bool try_get_online_cpus(void);
 232 extern void put_online_cpus(void);
 233 extern void cpu_hotplug_disable(void);
 234 extern void cpu_hotplug_enable(void);
 235 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 236 #define __hotcpu_notifier(fn, pri)      __cpu_notifier(fn, pri)
 237 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 238 #define __register_hotcpu_notifier(nb)  __register_cpu_notifier(nb)
 239 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 240 #define __unregister_hotcpu_notifier(nb)        __unregister_cpu_notifier(nb)
 241 void clear_tasks_mm_cpumask(int cpu);
 242 int cpu_down(unsigned int cpu);
 243
 244 #else           /* CONFIG_HOTPLUG_CPU */
 245
 246 static inline void cpu_hotplug_begin(void) {}
 247 static inline void cpu_hotplug_done(void) {}
 248 #define get_online_cpus()       do { } while (0)
 249 #define try_get_online_cpus()   true
 250 #define put_online_cpus()       do { } while (0)
 251 #define cpu_hotplug_disable()   do { } while (0)
 252 #define cpu_hotplug_enable()    do { } while (0)
 253 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 254 #define __hotcpu_notifier(fn, pri)      do { (void)(fn); } while (0)
 255 /* These aren't inline functions due to a GCC bug. */
 256 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 257 #define __register_hotcpu_notifier(nb)  ({ (void)(nb); 0; })
 258 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 259 #define __unregister_hotcpu_notifier(nb)        ({ (void)(nb); })
 260 #endif          /* CONFIG_HOTPLUG_CPU */
 261
 262 #ifdef CONFIG_PM_SLEEP_SMP
 263 extern int disable_nonboot_cpus(void);
 264 extern void enable_nonboot_cpus(void);
 265 #else /* !CONFIG_PM_SLEEP_SMP */
 266 static inline int disable_nonboot_cpus(void) { return 0; }
 267 static inline void enable_nonboot_cpus(void) {}
 268 #endif /* !CONFIG_PM_SLEEP_SMP */
 269
 270 enum cpuhp_state {
 271         CPUHP_OFFLINE,
 272         CPUHP_ONLINE,
 273 };
 274
 275 void cpu_startup_entry(enum cpuhp_state state);
 276
 277 void cpu_idle_poll_ctrl(bool enable);
 278
 279 void arch_cpu_idle(void);
 280 void arch_cpu_idle_prepare(void);
 281 void arch_cpu_idle_enter(void);
 282 void arch_cpu_idle_exit(void);
 283 void arch_cpu_idle_dead(void);
 284
 285 DECLARE_PER_CPU(bool, cpu_dead_idle);
 286
 287 int cpu_report_state(int cpu);
 288 int cpu_check_up_prepare(int cpu);
 289 void cpu_set_state_online(int cpu);
 290 #ifdef CONFIG_HOTPLUG_CPU
 291 bool cpu_wait_death(unsigned int cpu, int seconds);
 292 bool cpu_report_death(void);
 293 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
 294
 295 #endif /* _LINUX_CPU_H_ */