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 struct device_node; 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 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id); 33 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun, 34 int cpu, unsigned int *thread); 35 36 extern int cpu_add_dev_attr(struct device_attribute *attr); 37 extern void cpu_remove_dev_attr(struct device_attribute *attr); 38 39 extern int cpu_add_dev_attr_group(struct attribute_group *attrs); 40 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs); 41 42 #ifdef CONFIG_HOTPLUG_CPU 43 extern void unregister_cpu(struct cpu *cpu); 44 extern ssize_t arch_cpu_probe(const char *, size_t); 45 extern ssize_t arch_cpu_release(const char *, size_t); 46 #endif 47 struct notifier_block; 48 49 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE 50 extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env); 51 extern ssize_t arch_print_cpu_modalias(struct device *dev, 52 struct device_attribute *attr, 53 char *bufptr); 54 #endif 55 56 /* 57 * CPU notifier priorities. 58 */ 59 enum { 60 /* 61 * SCHED_ACTIVE marks a cpu which is coming up active during 62 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first 63 * notifier. CPUSET_ACTIVE adjusts cpuset according to 64 * cpu_active mask right after SCHED_ACTIVE. During 65 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are 66 * ordered in the similar way. 67 * 68 * This ordering guarantees consistent cpu_active mask and 69 * migration behavior to all cpu notifiers. 70 */ 71 CPU_PRI_SCHED_ACTIVE = INT_MAX, 72 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1, 73 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1, 74 CPU_PRI_CPUSET_INACTIVE = INT_MIN, 75 76 /* migration should happen before other stuff but after perf */ 77 CPU_PRI_PERF = 20, 78 CPU_PRI_MIGRATION = 10, 79 /* bring up workqueues before normal notifiers and down after */ 80 CPU_PRI_WORKQUEUE_UP = 5, 81 CPU_PRI_WORKQUEUE_DOWN = -5, 82 }; 83 84 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */ 85 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */ 86 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */ 87 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */ 88 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */ 89 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */ 90 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task, 91 * not handling interrupts, soon dead. 92 * Called on the dying cpu, interrupts 93 * are already disabled. Must not 94 * sleep, must not fail */ 95 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug 96 * lock is dropped */ 97 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running. 98 * Called on the new cpu, just before 99 * enabling interrupts. Must not sleep, 100 * must not fail */ 101 102 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend 103 * operation in progress 104 */ 105 #define CPU_TASKS_FROZEN 0x0010 106 107 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN) 108 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN) 109 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN) 110 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN) 111 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) 112 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) 113 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN) 114 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN) 115 116 117 #ifdef CONFIG_SMP 118 /* Need to know about CPUs going up/down? */ 119 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) 120 #define cpu_notifier(fn, pri) { \ 121 static struct notifier_block fn##_nb = \ 122 { .notifier_call = fn, .priority = pri }; \ 123 register_cpu_notifier(&fn##_nb); \ 124 } 125 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 126 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 127 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 128 #ifdef CONFIG_HOTPLUG_CPU 129 extern int register_cpu_notifier(struct notifier_block *nb); 130 extern void unregister_cpu_notifier(struct notifier_block *nb); 131 #else 132 133 #ifndef MODULE 134 extern int register_cpu_notifier(struct notifier_block *nb); 135 #else 136 static inline int register_cpu_notifier(struct notifier_block *nb) 137 { 138 return 0; 139 } 140 #endif 141 142 static inline void unregister_cpu_notifier(struct notifier_block *nb) 143 { 144 } 145 #endif 146 147 int cpu_up(unsigned int cpu); 148 void notify_cpu_starting(unsigned int cpu); 149 extern void cpu_maps_update_begin(void); 150 extern void cpu_maps_update_done(void); 151 152 #else /* CONFIG_SMP */ 153 154 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 155 156 static inline int register_cpu_notifier(struct notifier_block *nb) 157 { 158 return 0; 159 } 160 161 static inline void unregister_cpu_notifier(struct notifier_block *nb) 162 { 163 } 164 165 static inline void cpu_maps_update_begin(void) 166 { 167 } 168 169 static inline void cpu_maps_update_done(void) 170 { 171 } 172 173 #endif /* CONFIG_SMP */ 174 extern struct bus_type cpu_subsys; 175 176 #ifdef CONFIG_HOTPLUG_CPU 177 /* Stop CPUs going up and down. */ 178 179 extern void cpu_hotplug_begin(void); 180 extern void cpu_hotplug_done(void); 181 extern void get_online_cpus(void); 182 extern void put_online_cpus(void); 183 extern void cpu_hotplug_disable(void); 184 extern void cpu_hotplug_enable(void); 185 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri) 186 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 187 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 188 void clear_tasks_mm_cpumask(int cpu); 189 int cpu_down(unsigned int cpu); 190 191 #else /* CONFIG_HOTPLUG_CPU */ 192 193 static inline void cpu_hotplug_begin(void) {} 194 static inline void cpu_hotplug_done(void) {} 195 #define get_online_cpus() do { } while (0) 196 #define put_online_cpus() do { } while (0) 197 #define cpu_hotplug_disable() do { } while (0) 198 #define cpu_hotplug_enable() do { } while (0) 199 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 200 /* These aren't inline functions due to a GCC bug. */ 201 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; }) 202 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); }) 203 #endif /* CONFIG_HOTPLUG_CPU */ 204 205 #ifdef CONFIG_PM_SLEEP_SMP 206 extern int disable_nonboot_cpus(void); 207 extern void enable_nonboot_cpus(void); 208 #else /* !CONFIG_PM_SLEEP_SMP */ 209 static inline int disable_nonboot_cpus(void) { return 0; } 210 static inline void enable_nonboot_cpus(void) {} 211 #endif /* !CONFIG_PM_SLEEP_SMP */ 212 213 enum cpuhp_state { 214 CPUHP_OFFLINE, 215 CPUHP_ONLINE, 216 }; 217 218 void cpu_startup_entry(enum cpuhp_state state); 219 void cpu_idle(void); 220 221 void cpu_idle_poll_ctrl(bool enable); 222 223 void arch_cpu_idle(void); 224 void arch_cpu_idle_prepare(void); 225 void arch_cpu_idle_enter(void); 226 void arch_cpu_idle_exit(void); 227 void arch_cpu_idle_dead(void); 228 229 #endif /* _LINUX_CPU_H_ */ 230