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