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/device.h> 18 #include <linux/node.h> 19 #include <linux/compiler.h> 20 #include <linux/cpumask.h> 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 extern int sched_create_sysfs_power_savings_entries(struct device *dev); 39 40 #ifdef CONFIG_HOTPLUG_CPU 41 extern void unregister_cpu(struct cpu *cpu); 42 extern ssize_t arch_cpu_probe(const char *, size_t); 43 extern ssize_t arch_cpu_release(const char *, size_t); 44 #endif 45 struct notifier_block; 46 47 /* 48 * CPU notifier priorities. 49 */ 50 enum { 51 /* 52 * SCHED_ACTIVE marks a cpu which is coming up active during 53 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first 54 * notifier. CPUSET_ACTIVE adjusts cpuset according to 55 * cpu_active mask right after SCHED_ACTIVE. During 56 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are 57 * ordered in the similar way. 58 * 59 * This ordering guarantees consistent cpu_active mask and 60 * migration behavior to all cpu notifiers. 61 */ 62 CPU_PRI_SCHED_ACTIVE = INT_MAX, 63 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1, 64 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1, 65 CPU_PRI_CPUSET_INACTIVE = INT_MIN, 66 67 /* migration should happen before other stuff but after perf */ 68 CPU_PRI_PERF = 20, 69 CPU_PRI_MIGRATION = 10, 70 /* prepare workqueues for other notifiers */ 71 CPU_PRI_WORKQUEUE = 5, 72 }; 73 74 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */ 75 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */ 76 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */ 77 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */ 78 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */ 79 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */ 80 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task, 81 * not handling interrupts, soon dead. 82 * Called on the dying cpu, interrupts 83 * are already disabled. Must not 84 * sleep, must not fail */ 85 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug 86 * lock is dropped */ 87 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running. 88 * Called on the new cpu, just before 89 * enabling interrupts. Must not sleep, 90 * must not fail */ 91 92 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend 93 * operation in progress 94 */ 95 #define CPU_TASKS_FROZEN 0x0010 96 97 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN) 98 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN) 99 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN) 100 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN) 101 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) 102 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) 103 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN) 104 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN) 105 106 107 #ifdef CONFIG_SMP 108 /* Need to know about CPUs going up/down? */ 109 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) 110 #define cpu_notifier(fn, pri) { \ 111 static struct notifier_block fn##_nb __cpuinitdata = \ 112 { .notifier_call = fn, .priority = pri }; \ 113 register_cpu_notifier(&fn##_nb); \ 114 } 115 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 116 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 117 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */ 118 #ifdef CONFIG_HOTPLUG_CPU 119 extern int register_cpu_notifier(struct notifier_block *nb); 120 extern void unregister_cpu_notifier(struct notifier_block *nb); 121 #else 122 123 #ifndef MODULE 124 extern int register_cpu_notifier(struct notifier_block *nb); 125 #else 126 static inline int register_cpu_notifier(struct notifier_block *nb) 127 { 128 return 0; 129 } 130 #endif 131 132 static inline void unregister_cpu_notifier(struct notifier_block *nb) 133 { 134 } 135 #endif 136 137 int cpu_up(unsigned int cpu); 138 void notify_cpu_starting(unsigned int cpu); 139 extern void cpu_maps_update_begin(void); 140 extern void cpu_maps_update_done(void); 141 142 #else /* CONFIG_SMP */ 143 144 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) 145 146 static inline int register_cpu_notifier(struct notifier_block *nb) 147 { 148 return 0; 149 } 150 151 static inline void unregister_cpu_notifier(struct notifier_block *nb) 152 { 153 } 154 155 static inline void cpu_maps_update_begin(void) 156 { 157 } 158 159 static inline void cpu_maps_update_done(void) 160 { 161 } 162 163 #endif /* CONFIG_SMP */ 164 extern struct bus_type cpu_subsys; 165 166 #ifdef CONFIG_HOTPLUG_CPU 167 /* Stop CPUs going up and down. */ 168 169 extern void get_online_cpus(void); 170 extern void put_online_cpus(void); 171 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri) 172 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 173 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 174 int cpu_down(unsigned int cpu); 175 176 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE 177 extern void cpu_hotplug_driver_lock(void); 178 extern void cpu_hotplug_driver_unlock(void); 179 #else 180 static inline void cpu_hotplug_driver_lock(void) 181 { 182 } 183 184 static inline void cpu_hotplug_driver_unlock(void) 185 { 186 } 187 #endif 188 189 #else /* CONFIG_HOTPLUG_CPU */ 190 191 #define get_online_cpus() do { } while (0) 192 #define put_online_cpus() do { } while (0) 193 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 194 /* These aren't inline functions due to a GCC bug. */ 195 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; }) 196 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); }) 197 #endif /* CONFIG_HOTPLUG_CPU */ 198 199 #ifdef CONFIG_PM_SLEEP_SMP 200 extern int disable_nonboot_cpus(void); 201 extern void enable_nonboot_cpus(void); 202 #else /* !CONFIG_PM_SLEEP_SMP */ 203 static inline int disable_nonboot_cpus(void) { return 0; } 204 static inline void enable_nonboot_cpus(void) {} 205 #endif /* !CONFIG_PM_SLEEP_SMP */ 206 207 #endif /* _LINUX_CPU_H_ */ 208