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