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 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 74 extern __printf(4, 5) 75 struct device *cpu_device_create(struct device *parent, void *drvdata, 76 const struct attribute_group **groups, 77 const char *fmt, ...); 78 #ifdef CONFIG_HOTPLUG_CPU 79 extern void unregister_cpu(struct cpu *cpu); 80 extern ssize_t arch_cpu_probe(const char *, size_t); 81 extern ssize_t arch_cpu_release(const char *, size_t); 82 #endif 83 84 /* 85 * These states are not related to the core CPU hotplug mechanism. They are 86 * used by various (sub)architectures to track internal state 87 */ 88 #define CPU_ONLINE 0x0002 /* CPU is up */ 89 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 90 #define CPU_DEAD 0x0007 /* CPU dead */ 91 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 92 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 93 #define CPU_BROKEN 0x000B /* CPU did not die properly */ 94 95 #ifdef CONFIG_SMP 96 extern bool cpuhp_tasks_frozen; 97 int add_cpu(unsigned int cpu); 98 int cpu_device_up(struct device *dev); 99 void notify_cpu_starting(unsigned int cpu); 100 extern void cpu_maps_update_begin(void); 101 extern void cpu_maps_update_done(void); 102 int bringup_hibernate_cpu(unsigned int sleep_cpu); 103 void bringup_nonboot_cpus(unsigned int setup_max_cpus); 104 105 #else /* CONFIG_SMP */ 106 #define cpuhp_tasks_frozen 0 107 108 static inline void cpu_maps_update_begin(void) 109 { 110 } 111 112 static inline void cpu_maps_update_done(void) 113 { 114 } 115 116 static inline int add_cpu(unsigned int cpu) { return 0;} 117 118 #endif /* CONFIG_SMP */ 119 extern struct bus_type cpu_subsys; 120 121 extern int lockdep_is_cpus_held(void); 122 123 #ifdef CONFIG_HOTPLUG_CPU 124 extern void cpus_write_lock(void); 125 extern void cpus_write_unlock(void); 126 extern void cpus_read_lock(void); 127 extern void cpus_read_unlock(void); 128 extern int cpus_read_trylock(void); 129 extern void lockdep_assert_cpus_held(void); 130 extern void cpu_hotplug_disable(void); 131 extern void cpu_hotplug_enable(void); 132 void clear_tasks_mm_cpumask(int cpu); 133 int remove_cpu(unsigned int cpu); 134 int cpu_device_down(struct device *dev); 135 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); 136 137 #else /* CONFIG_HOTPLUG_CPU */ 138 139 static inline void cpus_write_lock(void) { } 140 static inline void cpus_write_unlock(void) { } 141 static inline void cpus_read_lock(void) { } 142 static inline void cpus_read_unlock(void) { } 143 static inline int cpus_read_trylock(void) { return true; } 144 static inline void lockdep_assert_cpus_held(void) { } 145 static inline void cpu_hotplug_disable(void) { } 146 static inline void cpu_hotplug_enable(void) { } 147 static inline int remove_cpu(unsigned int cpu) { return -EPERM; } 148 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } 149 #endif /* !CONFIG_HOTPLUG_CPU */ 150 151 #ifdef CONFIG_PM_SLEEP_SMP 152 extern int freeze_secondary_cpus(int primary); 153 extern void thaw_secondary_cpus(void); 154 155 static inline int suspend_disable_secondary_cpus(void) 156 { 157 int cpu = 0; 158 159 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 160 cpu = -1; 161 162 return freeze_secondary_cpus(cpu); 163 } 164 static inline void suspend_enable_secondary_cpus(void) 165 { 166 return thaw_secondary_cpus(); 167 } 168 169 #else /* !CONFIG_PM_SLEEP_SMP */ 170 static inline void thaw_secondary_cpus(void) {} 171 static inline int suspend_disable_secondary_cpus(void) { return 0; } 172 static inline void suspend_enable_secondary_cpus(void) { } 173 #endif /* !CONFIG_PM_SLEEP_SMP */ 174 175 void __noreturn cpu_startup_entry(enum cpuhp_state state); 176 177 void cpu_idle_poll_ctrl(bool enable); 178 179 bool cpu_in_idle(unsigned long pc); 180 181 void arch_cpu_idle(void); 182 void arch_cpu_idle_prepare(void); 183 void arch_cpu_idle_enter(void); 184 void arch_cpu_idle_exit(void); 185 void __noreturn arch_cpu_idle_dead(void); 186 187 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT 188 void arch_cpu_finalize_init(void); 189 #else 190 static inline void arch_cpu_finalize_init(void) { } 191 #endif 192 193 void cpu_set_state_online(int cpu); 194 void play_idle_precise(u64 duration_ns, u64 latency_ns); 195 196 static inline void play_idle(unsigned long duration_us) 197 { 198 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); 199 } 200 201 #ifdef CONFIG_HOTPLUG_CPU 202 void cpuhp_report_idle_dead(void); 203 #else 204 static inline void cpuhp_report_idle_dead(void) { } 205 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 206 207 enum cpuhp_smt_control { 208 CPU_SMT_ENABLED, 209 CPU_SMT_DISABLED, 210 CPU_SMT_FORCE_DISABLED, 211 CPU_SMT_NOT_SUPPORTED, 212 CPU_SMT_NOT_IMPLEMENTED, 213 }; 214 215 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT) 216 extern enum cpuhp_smt_control cpu_smt_control; 217 extern void cpu_smt_disable(bool force); 218 extern void cpu_smt_check_topology(void); 219 extern bool cpu_smt_possible(void); 220 extern int cpuhp_smt_enable(void); 221 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval); 222 #else 223 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) 224 static inline void cpu_smt_disable(bool force) { } 225 static inline void cpu_smt_check_topology(void) { } 226 static inline bool cpu_smt_possible(void) { return false; } 227 static inline int cpuhp_smt_enable(void) { return 0; } 228 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; } 229 #endif 230 231 extern bool cpu_mitigations_off(void); 232 extern bool cpu_mitigations_auto_nosmt(void); 233 234 #endif /* _LINUX_CPU_H_ */ 235