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