1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * include/linux/cpu.h - generic cpu definition 4 * 5 * This is mainly for topological representation. We define the 6 * basic 'struct cpu' here, which can be embedded in per-arch 7 * definitions of processors. 8 * 9 * Basic handling of the devices is done in drivers/base/cpu.c 10 * 11 * CPUs are exported via sysfs in the devices/system/cpu 12 * directory. 13 */ 14 #ifndef _LINUX_CPU_H_ 15 #define _LINUX_CPU_H_ 16 17 #include <linux/node.h> 18 #include <linux/compiler.h> 19 #include <linux/cpuhotplug.h> 20 #include <linux/cpu_smt.h> 21 22 struct device; 23 struct device_node; 24 struct attribute_group; 25 26 struct cpu { 27 int node_id; /* The node which contains the CPU */ 28 int hotpluggable; /* creates sysfs control file if hotpluggable */ 29 struct device dev; 30 }; 31 32 extern void boot_cpu_init(void); 33 extern void boot_cpu_hotplug_init(void); 34 extern void cpu_init(void); 35 extern void trap_init(void); 36 37 extern int register_cpu(struct cpu *cpu, int num); 38 extern struct device *get_cpu_device(unsigned cpu); 39 extern bool cpu_is_hotpluggable(unsigned cpu); 40 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id); 41 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun, 42 int cpu, unsigned int *thread); 43 44 extern int cpu_add_dev_attr(struct device_attribute *attr); 45 extern void cpu_remove_dev_attr(struct device_attribute *attr); 46 47 extern int cpu_add_dev_attr_group(struct attribute_group *attrs); 48 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs); 49 50 extern ssize_t cpu_show_meltdown(struct device *dev, 51 struct device_attribute *attr, char *buf); 52 extern ssize_t cpu_show_spectre_v1(struct device *dev, 53 struct device_attribute *attr, char *buf); 54 extern ssize_t cpu_show_spectre_v2(struct device *dev, 55 struct device_attribute *attr, char *buf); 56 extern ssize_t cpu_show_spec_store_bypass(struct device *dev, 57 struct device_attribute *attr, char *buf); 58 extern ssize_t cpu_show_l1tf(struct device *dev, 59 struct device_attribute *attr, char *buf); 60 extern ssize_t cpu_show_mds(struct device *dev, 61 struct device_attribute *attr, char *buf); 62 extern ssize_t cpu_show_tsx_async_abort(struct device *dev, 63 struct device_attribute *attr, 64 char *buf); 65 extern ssize_t cpu_show_itlb_multihit(struct device *dev, 66 struct device_attribute *attr, char *buf); 67 extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf); 68 extern ssize_t cpu_show_mmio_stale_data(struct device *dev, 69 struct device_attribute *attr, 70 char *buf); 71 extern ssize_t cpu_show_retbleed(struct device *dev, 72 struct device_attribute *attr, char *buf); 73 extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev, 74 struct device_attribute *attr, char *buf); 75 extern ssize_t cpu_show_gds(struct device *dev, 76 struct device_attribute *attr, char *buf); 77 extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev, 78 struct device_attribute *attr, char *buf); 79 80 extern __printf(4, 5) 81 struct device *cpu_device_create(struct device *parent, void *drvdata, 82 const struct attribute_group **groups, 83 const char *fmt, ...); 84 extern bool arch_cpu_is_hotpluggable(int cpu); 85 extern int arch_register_cpu(int cpu); 86 extern void arch_unregister_cpu(int cpu); 87 #ifdef CONFIG_HOTPLUG_CPU 88 extern void unregister_cpu(struct cpu *cpu); 89 extern ssize_t arch_cpu_probe(const char *, size_t); 90 extern ssize_t arch_cpu_release(const char *, size_t); 91 #endif 92 93 #ifdef CONFIG_GENERIC_CPU_DEVICES 94 DECLARE_PER_CPU(struct cpu, cpu_devices); 95 #endif 96 97 /* 98 * These states are not related to the core CPU hotplug mechanism. They are 99 * used by various (sub)architectures to track internal state 100 */ 101 #define CPU_ONLINE 0x0002 /* CPU is up */ 102 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 103 #define CPU_DEAD 0x0007 /* CPU dead */ 104 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 105 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 106 #define CPU_BROKEN 0x000B /* CPU did not die properly */ 107 108 #ifdef CONFIG_SMP 109 extern bool cpuhp_tasks_frozen; 110 int add_cpu(unsigned int cpu); 111 int cpu_device_up(struct device *dev); 112 void notify_cpu_starting(unsigned int cpu); 113 extern void cpu_maps_update_begin(void); 114 extern void cpu_maps_update_done(void); 115 int bringup_hibernate_cpu(unsigned int sleep_cpu); 116 void bringup_nonboot_cpus(unsigned int max_cpus); 117 118 #else /* CONFIG_SMP */ 119 #define cpuhp_tasks_frozen 0 120 121 static inline void cpu_maps_update_begin(void) 122 { 123 } 124 125 static inline void cpu_maps_update_done(void) 126 { 127 } 128 129 static inline int add_cpu(unsigned int cpu) { return 0;} 130 131 #endif /* CONFIG_SMP */ 132 extern const struct bus_type cpu_subsys; 133 134 extern int lockdep_is_cpus_held(void); 135 136 #ifdef CONFIG_HOTPLUG_CPU 137 extern void cpus_write_lock(void); 138 extern void cpus_write_unlock(void); 139 extern void cpus_read_lock(void); 140 extern void cpus_read_unlock(void); 141 extern int cpus_read_trylock(void); 142 extern void lockdep_assert_cpus_held(void); 143 extern void cpu_hotplug_disable(void); 144 extern void cpu_hotplug_enable(void); 145 void clear_tasks_mm_cpumask(int cpu); 146 int remove_cpu(unsigned int cpu); 147 int cpu_device_down(struct device *dev); 148 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); 149 150 #else /* CONFIG_HOTPLUG_CPU */ 151 152 static inline void cpus_write_lock(void) { } 153 static inline void cpus_write_unlock(void) { } 154 static inline void cpus_read_lock(void) { } 155 static inline void cpus_read_unlock(void) { } 156 static inline int cpus_read_trylock(void) { return true; } 157 static inline void lockdep_assert_cpus_held(void) { } 158 static inline void cpu_hotplug_disable(void) { } 159 static inline void cpu_hotplug_enable(void) { } 160 static inline int remove_cpu(unsigned int cpu) { return -EPERM; } 161 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } 162 #endif /* !CONFIG_HOTPLUG_CPU */ 163 164 DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock()) 165 166 #ifdef CONFIG_PM_SLEEP_SMP 167 extern int freeze_secondary_cpus(int primary); 168 extern void thaw_secondary_cpus(void); 169 170 static inline int suspend_disable_secondary_cpus(void) 171 { 172 int cpu = 0; 173 174 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 175 cpu = -1; 176 177 return freeze_secondary_cpus(cpu); 178 } 179 static inline void suspend_enable_secondary_cpus(void) 180 { 181 return thaw_secondary_cpus(); 182 } 183 184 #else /* !CONFIG_PM_SLEEP_SMP */ 185 static inline void thaw_secondary_cpus(void) {} 186 static inline int suspend_disable_secondary_cpus(void) { return 0; } 187 static inline void suspend_enable_secondary_cpus(void) { } 188 #endif /* !CONFIG_PM_SLEEP_SMP */ 189 190 void __noreturn cpu_startup_entry(enum cpuhp_state state); 191 192 void cpu_idle_poll_ctrl(bool enable); 193 194 bool cpu_in_idle(unsigned long pc); 195 196 void arch_cpu_idle(void); 197 void arch_cpu_idle_prepare(void); 198 void arch_cpu_idle_enter(void); 199 void arch_cpu_idle_exit(void); 200 void arch_tick_broadcast_enter(void); 201 void arch_tick_broadcast_exit(void); 202 void __noreturn arch_cpu_idle_dead(void); 203 204 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT 205 void arch_cpu_finalize_init(void); 206 #else 207 static inline void arch_cpu_finalize_init(void) { } 208 #endif 209 210 void play_idle_precise(u64 duration_ns, u64 latency_ns); 211 212 static inline void play_idle(unsigned long duration_us) 213 { 214 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); 215 } 216 217 #ifdef CONFIG_HOTPLUG_CPU 218 void cpuhp_report_idle_dead(void); 219 #else 220 static inline void cpuhp_report_idle_dead(void) { } 221 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 222 223 #ifdef CONFIG_CPU_MITIGATIONS 224 extern bool cpu_mitigations_off(void); 225 extern bool cpu_mitigations_auto_nosmt(void); 226 #else 227 static inline bool cpu_mitigations_off(void) 228 { 229 return true; 230 } 231 static inline bool cpu_mitigations_auto_nosmt(void) 232 { 233 return false; 234 } 235 #endif 236 237 #endif /* _LINUX_CPU_H_ */ 238