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 extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev, 75 struct device_attribute *attr, char *buf); 76 extern ssize_t cpu_show_gds(struct device *dev, 77 struct device_attribute *attr, char *buf); 78 79 extern __printf(4, 5) 80 struct device *cpu_device_create(struct device *parent, void *drvdata, 81 const struct attribute_group **groups, 82 const char *fmt, ...); 83 extern int arch_register_cpu(int cpu); 84 extern void arch_unregister_cpu(int cpu); 85 #ifdef CONFIG_HOTPLUG_CPU 86 extern void unregister_cpu(struct cpu *cpu); 87 extern ssize_t arch_cpu_probe(const char *, size_t); 88 extern ssize_t arch_cpu_release(const char *, size_t); 89 #endif 90 91 /* 92 * These states are not related to the core CPU hotplug mechanism. They are 93 * used by various (sub)architectures to track internal state 94 */ 95 #define CPU_ONLINE 0x0002 /* CPU is up */ 96 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 97 #define CPU_DEAD 0x0007 /* CPU dead */ 98 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 99 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 100 #define CPU_BROKEN 0x000B /* CPU did not die properly */ 101 102 #ifdef CONFIG_SMP 103 extern bool cpuhp_tasks_frozen; 104 int add_cpu(unsigned int cpu); 105 int cpu_device_up(struct device *dev); 106 void notify_cpu_starting(unsigned int cpu); 107 extern void cpu_maps_update_begin(void); 108 extern void cpu_maps_update_done(void); 109 int bringup_hibernate_cpu(unsigned int sleep_cpu); 110 void bringup_nonboot_cpus(unsigned int setup_max_cpus); 111 112 #else /* CONFIG_SMP */ 113 #define cpuhp_tasks_frozen 0 114 115 static inline void cpu_maps_update_begin(void) 116 { 117 } 118 119 static inline void cpu_maps_update_done(void) 120 { 121 } 122 123 static inline int add_cpu(unsigned int cpu) { return 0;} 124 125 #endif /* CONFIG_SMP */ 126 extern struct bus_type cpu_subsys; 127 128 extern int lockdep_is_cpus_held(void); 129 130 #ifdef CONFIG_HOTPLUG_CPU 131 extern void cpus_write_lock(void); 132 extern void cpus_write_unlock(void); 133 extern void cpus_read_lock(void); 134 extern void cpus_read_unlock(void); 135 extern int cpus_read_trylock(void); 136 extern void lockdep_assert_cpus_held(void); 137 extern void cpu_hotplug_disable(void); 138 extern void cpu_hotplug_enable(void); 139 void clear_tasks_mm_cpumask(int cpu); 140 int remove_cpu(unsigned int cpu); 141 int cpu_device_down(struct device *dev); 142 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); 143 144 #else /* CONFIG_HOTPLUG_CPU */ 145 146 static inline void cpus_write_lock(void) { } 147 static inline void cpus_write_unlock(void) { } 148 static inline void cpus_read_lock(void) { } 149 static inline void cpus_read_unlock(void) { } 150 static inline int cpus_read_trylock(void) { return true; } 151 static inline void lockdep_assert_cpus_held(void) { } 152 static inline void cpu_hotplug_disable(void) { } 153 static inline void cpu_hotplug_enable(void) { } 154 static inline int remove_cpu(unsigned int cpu) { return -EPERM; } 155 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } 156 #endif /* !CONFIG_HOTPLUG_CPU */ 157 158 DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock()) 159 160 #ifdef CONFIG_PM_SLEEP_SMP 161 extern int freeze_secondary_cpus(int primary); 162 extern void thaw_secondary_cpus(void); 163 164 static inline int suspend_disable_secondary_cpus(void) 165 { 166 int cpu = 0; 167 168 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 169 cpu = -1; 170 171 return freeze_secondary_cpus(cpu); 172 } 173 static inline void suspend_enable_secondary_cpus(void) 174 { 175 return thaw_secondary_cpus(); 176 } 177 178 #else /* !CONFIG_PM_SLEEP_SMP */ 179 static inline void thaw_secondary_cpus(void) {} 180 static inline int suspend_disable_secondary_cpus(void) { return 0; } 181 static inline void suspend_enable_secondary_cpus(void) { } 182 #endif /* !CONFIG_PM_SLEEP_SMP */ 183 184 void __noreturn cpu_startup_entry(enum cpuhp_state state); 185 186 void cpu_idle_poll_ctrl(bool enable); 187 188 bool cpu_in_idle(unsigned long pc); 189 190 void arch_cpu_idle(void); 191 void arch_cpu_idle_prepare(void); 192 void arch_cpu_idle_enter(void); 193 void arch_cpu_idle_exit(void); 194 void __noreturn arch_cpu_idle_dead(void); 195 196 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT 197 void arch_cpu_finalize_init(void); 198 #else 199 static inline void arch_cpu_finalize_init(void) { } 200 #endif 201 202 void play_idle_precise(u64 duration_ns, u64 latency_ns); 203 204 static inline void play_idle(unsigned long duration_us) 205 { 206 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); 207 } 208 209 #ifdef CONFIG_HOTPLUG_CPU 210 void cpuhp_report_idle_dead(void); 211 #else 212 static inline void cpuhp_report_idle_dead(void) { } 213 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 214 215 extern bool cpu_mitigations_off(void); 216 extern bool cpu_mitigations_auto_nosmt(void); 217 218 #endif /* _LINUX_CPU_H_ */ 219