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_ */ 183