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 * 10 * CPUs are exported via sysfs in the devices/system/cpu 11 * directory. 12 */ 13 #ifndef _LINUX_CPU_H_ 14 #define _LINUX_CPU_H_ 15 16 #include <linux/node.h> 17 #include <linux/compiler.h> 18 #include <linux/cpumask.h> 19 20 struct device; 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 #ifdef CONFIG_HOTPLUG_CPU 39 extern void unregister_cpu(struct cpu *cpu); 40 extern ssize_t arch_cpu_probe(const char *, size_t); 41 extern ssize_t arch_cpu_release(const char *, size_t); 42 #endif 43 struct notifier_block; 44 45 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE 46 extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env); 47 extern ssize_t arch_print_cpu_modalias(struct device *dev, 48 struct device_attribute *attr, 49 char *bufptr); 50 #endif 51 52 /* 53 * CPU notifier priorities. 54 */ 55 enum { 56 /* 57 * SCHED_ACTIVE marks a cpu which is coming up active during 58 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first 59 * notifier. CPUSET_ACTIVE adjusts cpuset according to 60 * cpu_active mask right after SCHED_ACTIVE. During 61 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are 62 * ordered in the similar way. 63 * 64 * This ordering guarantees consistent cpu_active mask and 65 * migration behavior to all cpu notifiers. 66 */ 67 CPU_PRI_SCHED_ACTIVE = INT_MAX, 68 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1, 69 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1, 70 CPU_PRI_CPUSET_INACTIVE = INT_MIN, 71 72 /* migration should happen before other stuff but after perf */ 73 CPU_PRI_PERF = 20, 74 CPU_PRI_MIGRATION = 10, 75 /* bring up workqueues before normal notifiers and down after */ 76 CPU_PRI_WORKQUEUE_UP = 5, 77 CPU_PRI_WORKQUEUE_DOWN = -5, 78 }; 79 80 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */ 81 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */ 82 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */ 83 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */ 84 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */ 85 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */ 86 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task, 87 * not handling interrupts, soon dead. 88 * Called on the dying cpu, interrupts 89 * are already disabled. Must not 90 * sleep, must not fail */ 91 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug 92 * lock is dropped */ 93 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running. 94 * Called on the new cpu, just before 95 * enabling interrupts. Must not sleep, 96 * must not fail */ 97 98 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend 99 * operation in progress 100 */ 101 #define CPU_TASKS_FROZEN 0x0010 102 103 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN) 104 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN) 105 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN) 106 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN) 107 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) 108 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) 109 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN) 110 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN) 111 112 113 #ifdef CONFIG_SMP 114 /* Need to know about CPUs going up/down? */ 115 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) 116 #define cpu_notifier(fn, pri) { \ 117 static struct notifier_block fn##_nb = \ 118 { .notifier_call = fn, .priority = pri }; \ 119 register_cpu_notifier(&fn##_nb); \ 120 } 121 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 122 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 123 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 124 #ifdef CONFIG_HOTPLUG_CPU 125 extern int register_cpu_notifier(struct notifier_block *nb); 126 extern void unregister_cpu_notifier(struct notifier_block *nb); 127 #else 128 129 #ifndef MODULE 130 extern int register_cpu_notifier(struct notifier_block *nb); 131 #else 132 static inline int register_cpu_notifier(struct notifier_block *nb) 133 { 134 return 0; 135 } 136 #endif 137 138 static inline void unregister_cpu_notifier(struct notifier_block *nb) 139 { 140 } 141 #endif 142 143 int cpu_up(unsigned int cpu); 144 void notify_cpu_starting(unsigned int cpu); 145 extern void cpu_maps_update_begin(void); 146 extern void cpu_maps_update_done(void); 147 148 #else /* CONFIG_SMP */ 149 150 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 151 152 static inline int register_cpu_notifier(struct notifier_block *nb) 153 { 154 return 0; 155 } 156 157 static inline void unregister_cpu_notifier(struct notifier_block *nb) 158 { 159 } 160 161 static inline void cpu_maps_update_begin(void) 162 { 163 } 164 165 static inline void cpu_maps_update_done(void) 166 { 167 } 168 169 #endif /* CONFIG_SMP */ 170 extern struct bus_type cpu_subsys; 171 172 #ifdef CONFIG_HOTPLUG_CPU 173 /* Stop CPUs going up and down. */ 174 175 extern void get_online_cpus(void); 176 extern void put_online_cpus(void); 177 extern void cpu_hotplug_disable(void); 178 extern void cpu_hotplug_enable(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 void clear_tasks_mm_cpumask(int cpu); 183 int cpu_down(unsigned int cpu); 184 185 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE 186 extern void cpu_hotplug_driver_lock(void); 187 extern void cpu_hotplug_driver_unlock(void); 188 #else 189 static inline void cpu_hotplug_driver_lock(void) 190 { 191 } 192 193 static inline void cpu_hotplug_driver_unlock(void) 194 { 195 } 196 #endif 197 198 #else /* CONFIG_HOTPLUG_CPU */ 199 200 #define get_online_cpus() do { } while (0) 201 #define put_online_cpus() do { } while (0) 202 #define cpu_hotplug_disable() do { } while (0) 203 #define cpu_hotplug_enable() do { } while (0) 204 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 205 /* These aren't inline functions due to a GCC bug. */ 206 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; }) 207 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); }) 208 #endif /* CONFIG_HOTPLUG_CPU */ 209 210 #ifdef CONFIG_PM_SLEEP_SMP 211 extern int disable_nonboot_cpus(void); 212 extern void enable_nonboot_cpus(void); 213 #else /* !CONFIG_PM_SLEEP_SMP */ 214 static inline int disable_nonboot_cpus(void) { return 0; } 215 static inline void enable_nonboot_cpus(void) {} 216 #endif /* !CONFIG_PM_SLEEP_SMP */ 217 218 enum cpuhp_state { 219 CPUHP_OFFLINE, 220 CPUHP_ONLINE, 221 }; 222 223 void cpu_startup_entry(enum cpuhp_state state); 224 void cpu_idle(void); 225 226 void cpu_idle_poll_ctrl(bool enable); 227 228 void arch_cpu_idle(void); 229 void arch_cpu_idle_prepare(void); 230 void arch_cpu_idle_enter(void); 231 void arch_cpu_idle_exit(void); 232 void arch_cpu_idle_dead(void); 233 234 #endif /* _LINUX_CPU_H_ */ 235