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  * Per-cpu interfaces can be implemented using a struct device_interface.
  15  * See the following for how to do this:
  16  * - drivers/base/intf.c
  17  * - Documentation/driver-model/interface.txt
  18  */
  19 #ifndef _LINUX_CPU_H_
  20 #define _LINUX_CPU_H_
  21
  22 #include <linux/sysdev.h>
  23 #include <linux/node.h>
  24 #include <linux/compiler.h>
  25 #include <linux/cpumask.h>
  26
  27 struct cpu {
  28         int node_id;            /* The node which contains the CPU */
  29         int hotpluggable;       /* creates sysfs control file if hotpluggable */
  30         struct sys_device sysdev;
  31 };
  32
  33 extern int register_cpu(struct cpu *cpu, int num);
  34 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
  35
  36 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
  37 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
  38
  39 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
  40 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
  41
  42 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  43
  44 #ifdef CONFIG_HOTPLUG_CPU
  45 extern void unregister_cpu(struct cpu *cpu);
  46 extern ssize_t arch_cpu_probe(const char *, size_t);
  47 extern ssize_t arch_cpu_release(const char *, size_t);
  48 #endif
  49 struct notifier_block;
  50
  51 /*
  52  * CPU notifier priorities.
  53  */
  54 enum {
  55         /*
  56          * SCHED_ACTIVE marks a cpu which is coming up active during
  57          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  58          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  59          * cpu_active mask right after SCHED_ACTIVE.  During
  60          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  61          * ordered in the similar way.
  62          *
  63          * This ordering guarantees consistent cpu_active mask and
  64          * migration behavior to all cpu notifiers.
  65          */
  66         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  67         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  68         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  69         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  70
  71         /* migration should happen before other stuff but after perf */
  72         CPU_PRI_PERF            = 20,
  73         CPU_PRI_MIGRATION       = 10,
  74         /* prepare workqueues for other notifiers */
  75         CPU_PRI_WORKQUEUE       = 5,
  76 };
  77
  78 #ifdef CONFIG_SMP
  79 /* Need to know about CPUs going up/down? */
  80 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
  81 #define cpu_notifier(fn, pri) {                                 \
  82         static struct notifier_block fn##_nb __cpuinitdata =    \
  83                 { .notifier_call = fn, .priority = pri };       \
  84         register_cpu_notifier(&fn##_nb);                        \
  85 }
  86 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  87 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
  88 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  89 #ifdef CONFIG_HOTPLUG_CPU
  90 extern int register_cpu_notifier(struct notifier_block *nb);
  91 extern void unregister_cpu_notifier(struct notifier_block *nb);
  92 #else
  93
  94 #ifndef MODULE
  95 extern int register_cpu_notifier(struct notifier_block *nb);
  96 #else
  97 static inline int register_cpu_notifier(struct notifier_block *nb)
  98 {
  99         return 0;
 100 }
 101 #endif
 102
 103 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 104 {
 105 }
 106 #endif
 107
 108 int cpu_up(unsigned int cpu);
 109 void notify_cpu_starting(unsigned int cpu);
 110 extern void cpu_maps_update_begin(void);
 111 extern void cpu_maps_update_done(void);
 112
 113 #else   /* CONFIG_SMP */
 114
 115 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 116
 117 static inline int register_cpu_notifier(struct notifier_block *nb)
 118 {
 119         return 0;
 120 }
 121
 122 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 123 {
 124 }
 125
 126 static inline void cpu_maps_update_begin(void)
 127 {
 128 }
 129
 130 static inline void cpu_maps_update_done(void)
 131 {
 132 }
 133
 134 #endif /* CONFIG_SMP */
 135 extern struct sysdev_class cpu_sysdev_class;
 136
 137 #ifdef CONFIG_HOTPLUG_CPU
 138 /* Stop CPUs going up and down. */
 139
 140 extern void get_online_cpus(void);
 141 extern void put_online_cpus(void);
 142 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 143 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 144 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 145 int cpu_down(unsigned int cpu);
 146
 147 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 148 extern void cpu_hotplug_driver_lock(void);
 149 extern void cpu_hotplug_driver_unlock(void);
 150 #else
 151 static inline void cpu_hotplug_driver_lock(void)
 152 {
 153 }
 154
 155 static inline void cpu_hotplug_driver_unlock(void)
 156 {
 157 }
 158 #endif
 159
 160 #else           /* CONFIG_HOTPLUG_CPU */
 161
 162 #define get_online_cpus()       do { } while (0)
 163 #define put_online_cpus()       do { } while (0)
 164 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 165 /* These aren't inline functions due to a GCC bug. */
 166 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 167 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 168 #endif          /* CONFIG_HOTPLUG_CPU */
 169
 170 #ifdef CONFIG_PM_SLEEP_SMP
 171 extern int suspend_cpu_hotplug;
 172
 173 extern int disable_nonboot_cpus(void);
 174 extern void enable_nonboot_cpus(void);
 175 #else /* !CONFIG_PM_SLEEP_SMP */
 176 #define suspend_cpu_hotplug     0
 177
 178 static inline int disable_nonboot_cpus(void) { return 0; }
 179 static inline void enable_nonboot_cpus(void) {}
 180 #endif /* !CONFIG_PM_SLEEP_SMP */
 181
 182 #endif /* _LINUX_CPU_H_ */