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/device.h>
  18 #include <linux/node.h>
  19 #include <linux/compiler.h>
  20 #include <linux/cpumask.h>
  21
  22 struct cpu {
  23         int node_id;            /* The node which contains the CPU */
  24         int hotpluggable;       /* creates sysfs control file if hotpluggable */
  25         struct device dev;
  26 };
  27
  28 extern int register_cpu(struct cpu *cpu, int num);
  29 extern struct device *get_cpu_device(unsigned cpu);
  30 extern bool cpu_is_hotpluggable(unsigned cpu);
  31
  32 extern int cpu_add_dev_attr(struct device_attribute *attr);
  33 extern void cpu_remove_dev_attr(struct device_attribute *attr);
  34
  35 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  36 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  37
  38 extern int sched_create_sysfs_power_savings_entries(struct device *dev);
  39
  40 #ifdef CONFIG_HOTPLUG_CPU
  41 extern void unregister_cpu(struct cpu *cpu);
  42 extern ssize_t arch_cpu_probe(const char *, size_t);
  43 extern ssize_t arch_cpu_release(const char *, size_t);
  44 #endif
  45 struct notifier_block;
  46
  47 /*
  48  * CPU notifier priorities.
  49  */
  50 enum {
  51         /*
  52          * SCHED_ACTIVE marks a cpu which is coming up active during
  53          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  54          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  55          * cpu_active mask right after SCHED_ACTIVE.  During
  56          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  57          * ordered in the similar way.
  58          *
  59          * This ordering guarantees consistent cpu_active mask and
  60          * migration behavior to all cpu notifiers.
  61          */
  62         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  63         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  64         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  65         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  66
  67         /* migration should happen before other stuff but after perf */
  68         CPU_PRI_PERF            = 20,
  69         CPU_PRI_MIGRATION       = 10,
  70         /* prepare workqueues for other notifiers */
  71         CPU_PRI_WORKQUEUE       = 5,
  72 };
  73
  74 #define CPU_ONLINE              0x0002 /* CPU (unsigned)v is up */
  75 #define CPU_UP_PREPARE          0x0003 /* CPU (unsigned)v coming up */
  76 #define CPU_UP_CANCELED         0x0004 /* CPU (unsigned)v NOT coming up */
  77 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
  78 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
  79 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
  80 #define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
  81                                         * not handling interrupts, soon dead.
  82                                         * Called on the dying cpu, interrupts
  83                                         * are already disabled. Must not
  84                                         * sleep, must not fail */
  85 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  86                                         * lock is dropped */
  87 #define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
  88                                         * Called on the new cpu, just before
  89                                         * enabling interrupts. Must not sleep,
  90                                         * must not fail */
  91
  92 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
  93  * operation in progress
  94  */
  95 #define CPU_TASKS_FROZEN        0x0010
  96
  97 #define CPU_ONLINE_FROZEN       (CPU_ONLINE | CPU_TASKS_FROZEN)
  98 #define CPU_UP_PREPARE_FROZEN   (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
  99 #define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
 100 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 101 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 102 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
 103 #define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
 104 #define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
 105
 106
 107 #ifdef CONFIG_SMP
 108 /* Need to know about CPUs going up/down? */
 109 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
 110 #define cpu_notifier(fn, pri) {                                 \
 111         static struct notifier_block fn##_nb __cpuinitdata =    \
 112                 { .notifier_call = fn, .priority = pri };       \
 113         register_cpu_notifier(&fn##_nb);                        \
 114 }
 115 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 116 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 117 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 118 #ifdef CONFIG_HOTPLUG_CPU
 119 extern int register_cpu_notifier(struct notifier_block *nb);
 120 extern void unregister_cpu_notifier(struct notifier_block *nb);
 121 #else
 122
 123 #ifndef MODULE
 124 extern int register_cpu_notifier(struct notifier_block *nb);
 125 #else
 126 static inline int register_cpu_notifier(struct notifier_block *nb)
 127 {
 128         return 0;
 129 }
 130 #endif
 131
 132 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 133 {
 134 }
 135 #endif
 136
 137 int cpu_up(unsigned int cpu);
 138 void notify_cpu_starting(unsigned int cpu);
 139 extern void cpu_maps_update_begin(void);
 140 extern void cpu_maps_update_done(void);
 141
 142 #else   /* CONFIG_SMP */
 143
 144 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 145
 146 static inline int register_cpu_notifier(struct notifier_block *nb)
 147 {
 148         return 0;
 149 }
 150
 151 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 152 {
 153 }
 154
 155 static inline void cpu_maps_update_begin(void)
 156 {
 157 }
 158
 159 static inline void cpu_maps_update_done(void)
 160 {
 161 }
 162
 163 #endif /* CONFIG_SMP */
 164 extern struct bus_type cpu_subsys;
 165
 166 #ifdef CONFIG_HOTPLUG_CPU
 167 /* Stop CPUs going up and down. */
 168
 169 extern void get_online_cpus(void);
 170 extern void put_online_cpus(void);
 171 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 172 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 173 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 174 int cpu_down(unsigned int cpu);
 175
 176 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 177 extern void cpu_hotplug_driver_lock(void);
 178 extern void cpu_hotplug_driver_unlock(void);
 179 #else
 180 static inline void cpu_hotplug_driver_lock(void)
 181 {
 182 }
 183
 184 static inline void cpu_hotplug_driver_unlock(void)
 185 {
 186 }
 187 #endif
 188
 189 #else           /* CONFIG_HOTPLUG_CPU */
 190
 191 #define get_online_cpus()       do { } while (0)
 192 #define put_online_cpus()       do { } while (0)
 193 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 194 /* These aren't inline functions due to a GCC bug. */
 195 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 196 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 197 #endif          /* CONFIG_HOTPLUG_CPU */
 198
 199 #ifdef CONFIG_PM_SLEEP_SMP
 200 extern int disable_nonboot_cpus(void);
 201 extern void enable_nonboot_cpus(void);
 202 #else /* !CONFIG_PM_SLEEP_SMP */
 203 static inline int disable_nonboot_cpus(void) { return 0; }
 204 static inline void enable_nonboot_cpus(void) {}
 205 #endif /* !CONFIG_PM_SLEEP_SMP */
 206
 207 #endif /* _LINUX_CPU_H_ */