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 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id); 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 #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 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE 47 extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env); 48 extern ssize_t arch_print_cpu_modalias(struct device *dev, 49 struct device_attribute *attr, 50 char *bufptr); 51 #endif 52 53 /* 54 * CPU notifier priorities. 55 */ 56 enum { 57 /* 58 * SCHED_ACTIVE marks a cpu which is coming up active during 59 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first 60 * notifier. CPUSET_ACTIVE adjusts cpuset according to 61 * cpu_active mask right after SCHED_ACTIVE. During 62 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are 63 * ordered in the similar way. 64 * 65 * This ordering guarantees consistent cpu_active mask and 66 * migration behavior to all cpu notifiers. 67 */ 68 CPU_PRI_SCHED_ACTIVE = INT_MAX, 69 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1, 70 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1, 71 CPU_PRI_CPUSET_INACTIVE = INT_MIN, 72 73 /* migration should happen before other stuff but after perf */ 74 CPU_PRI_PERF = 20, 75 CPU_PRI_MIGRATION = 10, 76 /* bring up workqueues before normal notifiers and down after */ 77 CPU_PRI_WORKQUEUE_UP = 5, 78 CPU_PRI_WORKQUEUE_DOWN = -5, 79 }; 80 81 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */ 82 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */ 83 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */ 84 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */ 85 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */ 86 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */ 87 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task, 88 * not handling interrupts, soon dead. 89 * Called on the dying cpu, interrupts 90 * are already disabled. Must not 91 * sleep, must not fail */ 92 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug 93 * lock is dropped */ 94 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running. 95 * Called on the new cpu, just before 96 * enabling interrupts. Must not sleep, 97 * must not fail */ 98 99 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend 100 * operation in progress 101 */ 102 #define CPU_TASKS_FROZEN 0x0010 103 104 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN) 105 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN) 106 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN) 107 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN) 108 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) 109 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) 110 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN) 111 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN) 112 113 114 #ifdef CONFIG_SMP 115 /* Need to know about CPUs going up/down? */ 116 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) 117 #define cpu_notifier(fn, pri) { \ 118 static struct notifier_block fn##_nb = \ 119 { .notifier_call = fn, .priority = pri }; \ 120 register_cpu_notifier(&fn##_nb); \ 121 } 122 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 123 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 124 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 125 #ifdef CONFIG_HOTPLUG_CPU 126 extern int register_cpu_notifier(struct notifier_block *nb); 127 extern void unregister_cpu_notifier(struct notifier_block *nb); 128 #else 129 130 #ifndef MODULE 131 extern int register_cpu_notifier(struct notifier_block *nb); 132 #else 133 static inline int register_cpu_notifier(struct notifier_block *nb) 134 { 135 return 0; 136 } 137 #endif 138 139 static inline void unregister_cpu_notifier(struct notifier_block *nb) 140 { 141 } 142 #endif 143 144 int cpu_up(unsigned int cpu); 145 void notify_cpu_starting(unsigned int cpu); 146 extern void cpu_maps_update_begin(void); 147 extern void cpu_maps_update_done(void); 148 149 #else /* CONFIG_SMP */ 150 151 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 152 153 static inline int register_cpu_notifier(struct notifier_block *nb) 154 { 155 return 0; 156 } 157 158 static inline void unregister_cpu_notifier(struct notifier_block *nb) 159 { 160 } 161 162 static inline void cpu_maps_update_begin(void) 163 { 164 } 165 166 static inline void cpu_maps_update_done(void) 167 { 168 } 169 170 #endif /* CONFIG_SMP */ 171 extern struct bus_type cpu_subsys; 172 173 #ifdef CONFIG_HOTPLUG_CPU 174 /* Stop CPUs going up and down. */ 175 176 extern void cpu_hotplug_begin(void); 177 extern void cpu_hotplug_done(void); 178 extern void get_online_cpus(void); 179 extern void put_online_cpus(void); 180 extern void cpu_hotplug_disable(void); 181 extern void cpu_hotplug_enable(void); 182 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri) 183 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 184 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 185 void clear_tasks_mm_cpumask(int cpu); 186 int cpu_down(unsigned int cpu); 187 188 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE 189 extern void cpu_hotplug_driver_lock(void); 190 extern void cpu_hotplug_driver_unlock(void); 191 #else 192 static inline void cpu_hotplug_driver_lock(void) 193 { 194 } 195 196 static inline void cpu_hotplug_driver_unlock(void) 197 { 198 } 199 #endif 200 201 #else /* CONFIG_HOTPLUG_CPU */ 202 203 static inline void cpu_hotplug_begin(void) {} 204 static inline void cpu_hotplug_done(void) {} 205 #define get_online_cpus() do { } while (0) 206 #define put_online_cpus() do { } while (0) 207 #define cpu_hotplug_disable() do { } while (0) 208 #define cpu_hotplug_enable() do { } while (0) 209 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 210 /* These aren't inline functions due to a GCC bug. */ 211 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; }) 212 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); }) 213 #endif /* CONFIG_HOTPLUG_CPU */ 214 215 #ifdef CONFIG_PM_SLEEP_SMP 216 extern int disable_nonboot_cpus(void); 217 extern void enable_nonboot_cpus(void); 218 #else /* !CONFIG_PM_SLEEP_SMP */ 219 static inline int disable_nonboot_cpus(void) { return 0; } 220 static inline void enable_nonboot_cpus(void) {} 221 #endif /* !CONFIG_PM_SLEEP_SMP */ 222 223 enum cpuhp_state { 224 CPUHP_OFFLINE, 225 CPUHP_ONLINE, 226 }; 227 228 void cpu_startup_entry(enum cpuhp_state state); 229 void cpu_idle(void); 230 231 void cpu_idle_poll_ctrl(bool enable); 232 233 void arch_cpu_idle(void); 234 void arch_cpu_idle_prepare(void); 235 void arch_cpu_idle_enter(void); 236 void arch_cpu_idle_exit(void); 237 void arch_cpu_idle_dead(void); 238 239 #endif /* _LINUX_CPU_H_ */ 240