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 struct device *cpu_device_create(struct device *parent, void *drvdata,
  44                                         const struct attribute_group **groups,
  45                                         const char *fmt, ...);
  46 #ifdef CONFIG_HOTPLUG_CPU
  47 extern void unregister_cpu(struct cpu *cpu);
  48 extern ssize_t arch_cpu_probe(const char *, size_t);
  49 extern ssize_t arch_cpu_release(const char *, size_t);
  50 #endif
  51 struct notifier_block;
  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 =                  \
 119                 { .notifier_call = fn, .priority = pri };       \
 120         register_cpu_notifier(&fn##_nb);                        \
 121 }
 122
 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 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 129 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 130 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
 131 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 132
 133 #ifdef CONFIG_HOTPLUG_CPU
 134 extern int register_cpu_notifier(struct notifier_block *nb);
 135 extern int __register_cpu_notifier(struct notifier_block *nb);
 136 extern void unregister_cpu_notifier(struct notifier_block *nb);
 137 extern void __unregister_cpu_notifier(struct notifier_block *nb);
 138 #else
 139
 140 #ifndef MODULE
 141 extern int register_cpu_notifier(struct notifier_block *nb);
 142 extern int __register_cpu_notifier(struct notifier_block *nb);
 143 #else
 144 static inline int register_cpu_notifier(struct notifier_block *nb)
 145 {
 146         return 0;
 147 }
 148
 149 static inline int __register_cpu_notifier(struct notifier_block *nb)
 150 {
 151         return 0;
 152 }
 153 #endif
 154
 155 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 156 {
 157 }
 158
 159 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
 160 {
 161 }
 162 #endif
 163
 164 int cpu_up(unsigned int cpu);
 165 void notify_cpu_starting(unsigned int cpu);
 166 extern void cpu_maps_update_begin(void);
 167 extern void cpu_maps_update_done(void);
 168
 169 #define cpu_notifier_register_begin     cpu_maps_update_begin
 170 #define cpu_notifier_register_done      cpu_maps_update_done
 171
 172 #else   /* CONFIG_SMP */
 173
 174 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 175 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
 176
 177 static inline int register_cpu_notifier(struct notifier_block *nb)
 178 {
 179         return 0;
 180 }
 181
 182 static inline int __register_cpu_notifier(struct notifier_block *nb)
 183 {
 184         return 0;
 185 }
 186
 187 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 188 {
 189 }
 190
 191 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
 192 {
 193 }
 194
 195 static inline void cpu_maps_update_begin(void)
 196 {
 197 }
 198
 199 static inline void cpu_maps_update_done(void)
 200 {
 201 }
 202
 203 static inline void cpu_notifier_register_begin(void)
 204 {
 205 }
 206
 207 static inline void cpu_notifier_register_done(void)
 208 {
 209 }
 210
 211 #endif /* CONFIG_SMP */
 212 extern struct bus_type cpu_subsys;
 213
 214 #ifdef CONFIG_HOTPLUG_CPU
 215 /* Stop CPUs going up and down. */
 216
 217 extern void cpu_hotplug_begin(void);
 218 extern void cpu_hotplug_done(void);
 219 extern void get_online_cpus(void);
 220 extern bool try_get_online_cpus(void);
 221 extern void put_online_cpus(void);
 222 extern void cpu_hotplug_disable(void);
 223 extern void cpu_hotplug_enable(void);
 224 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 225 #define __hotcpu_notifier(fn, pri)      __cpu_notifier(fn, pri)
 226 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 227 #define __register_hotcpu_notifier(nb)  __register_cpu_notifier(nb)
 228 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 229 #define __unregister_hotcpu_notifier(nb)        __unregister_cpu_notifier(nb)
 230 void clear_tasks_mm_cpumask(int cpu);
 231 int cpu_down(unsigned int cpu);
 232
 233 #else           /* CONFIG_HOTPLUG_CPU */
 234
 235 static inline void cpu_hotplug_begin(void) {}
 236 static inline void cpu_hotplug_done(void) {}
 237 #define get_online_cpus()       do { } while (0)
 238 #define try_get_online_cpus()   true
 239 #define put_online_cpus()       do { } while (0)
 240 #define cpu_hotplug_disable()   do { } while (0)
 241 #define cpu_hotplug_enable()    do { } while (0)
 242 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 243 #define __hotcpu_notifier(fn, pri)      do { (void)(fn); } while (0)
 244 /* These aren't inline functions due to a GCC bug. */
 245 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 246 #define __register_hotcpu_notifier(nb)  ({ (void)(nb); 0; })
 247 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 248 #define __unregister_hotcpu_notifier(nb)        ({ (void)(nb); })
 249 #endif          /* CONFIG_HOTPLUG_CPU */
 250
 251 #ifdef CONFIG_PM_SLEEP_SMP
 252 extern int disable_nonboot_cpus(void);
 253 extern void enable_nonboot_cpus(void);
 254 #else /* !CONFIG_PM_SLEEP_SMP */
 255 static inline int disable_nonboot_cpus(void) { return 0; }
 256 static inline void enable_nonboot_cpus(void) {}
 257 #endif /* !CONFIG_PM_SLEEP_SMP */
 258
 259 enum cpuhp_state {
 260         CPUHP_OFFLINE,
 261         CPUHP_ONLINE,
 262 };
 263
 264 void cpu_startup_entry(enum cpuhp_state state);
 265
 266 void cpu_idle_poll_ctrl(bool enable);
 267
 268 void arch_cpu_idle(void);
 269 void arch_cpu_idle_prepare(void);
 270 void arch_cpu_idle_enter(void);
 271 void arch_cpu_idle_exit(void);
 272 void arch_cpu_idle_dead(void);
 273
 274 #endif /* _LINUX_CPU_H_ */