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_ */ 216