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/sysdev.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 sys_device sysdev;
  26 };
  27
  28 extern int register_cpu(struct cpu *cpu, int num);
  29 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
  30
  31 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
  32 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
  33
  34 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
  35 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
  36
  37 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  38
  39 #ifdef CONFIG_HOTPLUG_CPU
  40 extern void unregister_cpu(struct cpu *cpu);
  41 extern ssize_t arch_cpu_probe(const char *, size_t);
  42 extern ssize_t arch_cpu_release(const char *, size_t);
  43 #endif
  44 struct notifier_block;
  45
  46 /*
  47  * CPU notifier priorities.
  48  */
  49 enum {
  50         /*
  51          * SCHED_ACTIVE marks a cpu which is coming up active during
  52          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  53          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  54          * cpu_active mask right after SCHED_ACTIVE.  During
  55          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  56          * ordered in the similar way.
  57          *
  58          * This ordering guarantees consistent cpu_active mask and
  59          * migration behavior to all cpu notifiers.
  60          */
  61         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  62         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  63         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  64         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  65
  66         /* migration should happen before other stuff but after perf */
  67         CPU_PRI_PERF            = 20,
  68         CPU_PRI_MIGRATION       = 10,
  69         /* prepare workqueues for other notifiers */
  70         CPU_PRI_WORKQUEUE       = 5,
  71 };
  72
  73 #ifdef CONFIG_SMP
  74 /* Need to know about CPUs going up/down? */
  75 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
  76 #define cpu_notifier(fn, pri) {                                 \
  77         static struct notifier_block fn##_nb __cpuinitdata =    \
  78                 { .notifier_call = fn, .priority = pri };       \
  79         register_cpu_notifier(&fn##_nb);                        \
  80 }
  81 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  82 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
  83 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  84 #ifdef CONFIG_HOTPLUG_CPU
  85 extern int register_cpu_notifier(struct notifier_block *nb);
  86 extern void unregister_cpu_notifier(struct notifier_block *nb);
  87 #else
  88
  89 #ifndef MODULE
  90 extern int register_cpu_notifier(struct notifier_block *nb);
  91 #else
  92 static inline int register_cpu_notifier(struct notifier_block *nb)
  93 {
  94         return 0;
  95 }
  96 #endif
  97
  98 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  99 {
 100 }
 101 #endif
 102
 103 int cpu_up(unsigned int cpu);
 104 void notify_cpu_starting(unsigned int cpu);
 105 extern void cpu_maps_update_begin(void);
 106 extern void cpu_maps_update_done(void);
 107
 108 #else   /* CONFIG_SMP */
 109
 110 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 111
 112 static inline int register_cpu_notifier(struct notifier_block *nb)
 113 {
 114         return 0;
 115 }
 116
 117 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 118 {
 119 }
 120
 121 static inline void cpu_maps_update_begin(void)
 122 {
 123 }
 124
 125 static inline void cpu_maps_update_done(void)
 126 {
 127 }
 128
 129 #endif /* CONFIG_SMP */
 130 extern struct sysdev_class cpu_sysdev_class;
 131
 132 #ifdef CONFIG_HOTPLUG_CPU
 133 /* Stop CPUs going up and down. */
 134
 135 extern void get_online_cpus(void);
 136 extern void put_online_cpus(void);
 137 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 138 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 139 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 140 int cpu_down(unsigned int cpu);
 141
 142 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 143 extern void cpu_hotplug_driver_lock(void);
 144 extern void cpu_hotplug_driver_unlock(void);
 145 #else
 146 static inline void cpu_hotplug_driver_lock(void)
 147 {
 148 }
 149
 150 static inline void cpu_hotplug_driver_unlock(void)
 151 {
 152 }
 153 #endif
 154
 155 #else           /* CONFIG_HOTPLUG_CPU */
 156
 157 #define get_online_cpus()       do { } while (0)
 158 #define put_online_cpus()       do { } while (0)
 159 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 160 /* These aren't inline functions due to a GCC bug. */
 161 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 162 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 163 #endif          /* CONFIG_HOTPLUG_CPU */
 164
 165 #ifdef CONFIG_PM_SLEEP_SMP
 166 extern int suspend_cpu_hotplug;
 167
 168 extern int disable_nonboot_cpus(void);
 169 extern void enable_nonboot_cpus(void);
 170 #else /* !CONFIG_PM_SLEEP_SMP */
 171 #define suspend_cpu_hotplug     0
 172
 173 static inline int disable_nonboot_cpus(void) { return 0; }
 174 static inline void enable_nonboot_cpus(void) {}
 175 #endif /* !CONFIG_PM_SLEEP_SMP */
 176
 177 #endif /* _LINUX_CPU_H_ */