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  * and system devices are handled in drivers/base/sys.c.
  10  *
  11  * CPUs are exported via sysfs in the class/cpu/devices/
  12  * directory.
  13  */
  14 #ifndef _LINUX_CPU_H_
  15 #define _LINUX_CPU_H_
  16
  17 #include <linux/node.h>
  18 #include <linux/compiler.h>
  19 #include <linux/cpumask.h>
  20
  21 struct device;
  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
  33 extern int cpu_add_dev_attr(struct device_attribute *attr);
  34 extern void cpu_remove_dev_attr(struct device_attribute *attr);
  35
  36 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  37 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  38
  39 extern int sched_create_sysfs_power_savings_entries(struct device *dev);
  40
  41 #ifdef CONFIG_HOTPLUG_CPU
  42 extern void unregister_cpu(struct cpu *cpu);
  43 extern ssize_t arch_cpu_probe(const char *, size_t);
  44 extern ssize_t arch_cpu_release(const char *, size_t);
  45 #endif
  46 struct notifier_block;
  47
  48 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
  49 extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
  50 extern ssize_t arch_print_cpu_modalias(struct device *dev,
  51                                        struct device_attribute *attr,
  52                                        char *bufptr);
  53 #endif
  54
  55 /*
  56  * CPU notifier priorities.
  57  */
  58 enum {
  59         /*
  60          * SCHED_ACTIVE marks a cpu which is coming up active during
  61          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  62          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  63          * cpu_active mask right after SCHED_ACTIVE.  During
  64          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  65          * ordered in the similar way.
  66          *
  67          * This ordering guarantees consistent cpu_active mask and
  68          * migration behavior to all cpu notifiers.
  69          */
  70         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  71         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  72         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  73         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  74
  75         /* migration should happen before other stuff but after perf */
  76         CPU_PRI_PERF            = 20,
  77         CPU_PRI_MIGRATION       = 10,
  78         /* prepare workqueues for other notifiers */
  79         CPU_PRI_WORKQUEUE       = 5,
  80 };
  81
  82 #define CPU_ONLINE              0x0002 /* CPU (unsigned)v is up */
  83 #define CPU_UP_PREPARE          0x0003 /* CPU (unsigned)v coming up */
  84 #define CPU_UP_CANCELED         0x0004 /* CPU (unsigned)v NOT coming up */
  85 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
  86 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
  87 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
  88 #define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
  89                                         * not handling interrupts, soon dead.
  90                                         * Called on the dying cpu, interrupts
  91                                         * are already disabled. Must not
  92                                         * sleep, must not fail */
  93 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  94                                         * lock is dropped */
  95 #define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
  96                                         * Called on the new cpu, just before
  97                                         * enabling interrupts. Must not sleep,
  98                                         * must not fail */
  99
 100 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
 101  * operation in progress
 102  */
 103 #define CPU_TASKS_FROZEN        0x0010
 104
 105 #define CPU_ONLINE_FROZEN       (CPU_ONLINE | CPU_TASKS_FROZEN)
 106 #define CPU_UP_PREPARE_FROZEN   (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
 107 #define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
 108 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 109 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 110 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
 111 #define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
 112 #define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
 113
 114
 115 #ifdef CONFIG_SMP
 116 /* Need to know about CPUs going up/down? */
 117 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
 118 #define cpu_notifier(fn, pri) {                                 \
 119         static struct notifier_block fn##_nb __cpuinitdata =    \
 120                 { .notifier_call = fn, .priority = pri };       \
 121         register_cpu_notifier(&fn##_nb);                        \
 122 }
 123 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 124 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 125 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 126 #ifdef CONFIG_HOTPLUG_CPU
 127 extern int register_cpu_notifier(struct notifier_block *nb);
 128 extern void unregister_cpu_notifier(struct notifier_block *nb);
 129 #else
 130
 131 #ifndef MODULE
 132 extern int register_cpu_notifier(struct notifier_block *nb);
 133 #else
 134 static inline int register_cpu_notifier(struct notifier_block *nb)
 135 {
 136         return 0;
 137 }
 138 #endif
 139
 140 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 141 {
 142 }
 143 #endif
 144
 145 int cpu_up(unsigned int cpu);
 146 void notify_cpu_starting(unsigned int cpu);
 147 extern void cpu_maps_update_begin(void);
 148 extern void cpu_maps_update_done(void);
 149
 150 #else   /* CONFIG_SMP */
 151
 152 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 153
 154 static inline int register_cpu_notifier(struct notifier_block *nb)
 155 {
 156         return 0;
 157 }
 158
 159 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 160 {
 161 }
 162
 163 static inline void cpu_maps_update_begin(void)
 164 {
 165 }
 166
 167 static inline void cpu_maps_update_done(void)
 168 {
 169 }
 170
 171 #endif /* CONFIG_SMP */
 172 extern struct bus_type cpu_subsys;
 173
 174 #ifdef CONFIG_HOTPLUG_CPU
 175 /* Stop CPUs going up and down. */
 176
 177 extern void get_online_cpus(void);
 178 extern void put_online_cpus(void);
 179 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 180 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 181 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 182 int cpu_down(unsigned int cpu);
 183
 184 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 185 extern void cpu_hotplug_driver_lock(void);
 186 extern void cpu_hotplug_driver_unlock(void);
 187 #else
 188 static inline void cpu_hotplug_driver_lock(void)
 189 {
 190 }
 191
 192 static inline void cpu_hotplug_driver_unlock(void)
 193 {
 194 }
 195 #endif
 196
 197 #else           /* CONFIG_HOTPLUG_CPU */
 198
 199 #define get_online_cpus()       do { } while (0)
 200 #define put_online_cpus()       do { } while (0)
 201 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 202 /* These aren't inline functions due to a GCC bug. */
 203 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 204 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 205 #endif          /* CONFIG_HOTPLUG_CPU */
 206
 207 #ifdef CONFIG_PM_SLEEP_SMP
 208 extern int disable_nonboot_cpus(void);
 209 extern void enable_nonboot_cpus(void);
 210 #else /* !CONFIG_PM_SLEEP_SMP */
 211 static inline int disable_nonboot_cpus(void) { return 0; }
 212 static inline void enable_nonboot_cpus(void) {}
 213 #endif /* !CONFIG_PM_SLEEP_SMP */
 214
 215 #endif /* _LINUX_CPU_H_ */