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 extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev, 74 struct device_attribute *attr, char *buf); 75 76 extern __printf(4, 5) 77 struct device *cpu_device_create(struct device *parent, void *drvdata, 78 const struct attribute_group **groups, 79 const char *fmt, ...); 80 #ifdef CONFIG_HOTPLUG_CPU 81 extern void unregister_cpu(struct cpu *cpu); 82 extern ssize_t arch_cpu_probe(const char *, size_t); 83 extern ssize_t arch_cpu_release(const char *, size_t); 84 #endif 85 86 /* 87 * These states are not related to the core CPU hotplug mechanism. They are 88 * used by various (sub)architectures to track internal state 89 */ 90 #define CPU_ONLINE 0x0002 /* CPU is up */ 91 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 92 #define CPU_DEAD 0x0007 /* CPU dead */ 93 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 94 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 95 #define CPU_BROKEN 0x000B /* CPU did not die properly */ 96 97 #ifdef CONFIG_SMP 98 extern bool cpuhp_tasks_frozen; 99 int add_cpu(unsigned int cpu); 100 int cpu_device_up(struct device *dev); 101 void notify_cpu_starting(unsigned int cpu); 102 extern void cpu_maps_update_begin(void); 103 extern void cpu_maps_update_done(void); 104 int bringup_hibernate_cpu(unsigned int sleep_cpu); 105 void bringup_nonboot_cpus(unsigned int setup_max_cpus); 106 107 #else /* CONFIG_SMP */ 108 #define cpuhp_tasks_frozen 0 109 110 static inline void cpu_maps_update_begin(void) 111 { 112 } 113 114 static inline void cpu_maps_update_done(void) 115 { 116 } 117 118 static inline int add_cpu(unsigned int cpu) { return 0;} 119 120 #endif /* CONFIG_SMP */ 121 extern struct bus_type cpu_subsys; 122 123 extern int lockdep_is_cpus_held(void); 124 125 #ifdef CONFIG_HOTPLUG_CPU 126 extern void cpus_write_lock(void); 127 extern void cpus_write_unlock(void); 128 extern void cpus_read_lock(void); 129 extern void cpus_read_unlock(void); 130 extern int cpus_read_trylock(void); 131 extern void lockdep_assert_cpus_held(void); 132 extern void cpu_hotplug_disable(void); 133 extern void cpu_hotplug_enable(void); 134 void clear_tasks_mm_cpumask(int cpu); 135 int remove_cpu(unsigned int cpu); 136 int cpu_device_down(struct device *dev); 137 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); 138 139 #else /* CONFIG_HOTPLUG_CPU */ 140 141 static inline void cpus_write_lock(void) { } 142 static inline void cpus_write_unlock(void) { } 143 static inline void cpus_read_lock(void) { } 144 static inline void cpus_read_unlock(void) { } 145 static inline int cpus_read_trylock(void) { return true; } 146 static inline void lockdep_assert_cpus_held(void) { } 147 static inline void cpu_hotplug_disable(void) { } 148 static inline void cpu_hotplug_enable(void) { } 149 static inline int remove_cpu(unsigned int cpu) { return -EPERM; } 150 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } 151 #endif /* !CONFIG_HOTPLUG_CPU */ 152 153 #ifdef CONFIG_PM_SLEEP_SMP 154 extern int freeze_secondary_cpus(int primary); 155 extern void thaw_secondary_cpus(void); 156 157 static inline int suspend_disable_secondary_cpus(void) 158 { 159 int cpu = 0; 160 161 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 162 cpu = -1; 163 164 return freeze_secondary_cpus(cpu); 165 } 166 static inline void suspend_enable_secondary_cpus(void) 167 { 168 return thaw_secondary_cpus(); 169 } 170 171 #else /* !CONFIG_PM_SLEEP_SMP */ 172 static inline void thaw_secondary_cpus(void) {} 173 static inline int suspend_disable_secondary_cpus(void) { return 0; } 174 static inline void suspend_enable_secondary_cpus(void) { } 175 #endif /* !CONFIG_PM_SLEEP_SMP */ 176 177 void __noreturn cpu_startup_entry(enum cpuhp_state state); 178 179 void cpu_idle_poll_ctrl(bool enable); 180 181 bool cpu_in_idle(unsigned long pc); 182 183 void arch_cpu_idle(void); 184 void arch_cpu_idle_prepare(void); 185 void arch_cpu_idle_enter(void); 186 void arch_cpu_idle_exit(void); 187 void __noreturn arch_cpu_idle_dead(void); 188 189 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT 190 void arch_cpu_finalize_init(void); 191 #else 192 static inline void arch_cpu_finalize_init(void) { } 193 #endif 194 195 void cpu_set_state_online(int cpu); 196 void play_idle_precise(u64 duration_ns, u64 latency_ns); 197 198 static inline void play_idle(unsigned long duration_us) 199 { 200 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); 201 } 202 203 #ifdef CONFIG_HOTPLUG_CPU 204 void cpuhp_report_idle_dead(void); 205 #else 206 static inline void cpuhp_report_idle_dead(void) { } 207 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 208 209 enum cpuhp_smt_control { 210 CPU_SMT_ENABLED, 211 CPU_SMT_DISABLED, 212 CPU_SMT_FORCE_DISABLED, 213 CPU_SMT_NOT_SUPPORTED, 214 CPU_SMT_NOT_IMPLEMENTED, 215 }; 216 217 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT) 218 extern enum cpuhp_smt_control cpu_smt_control; 219 extern void cpu_smt_disable(bool force); 220 extern void cpu_smt_check_topology(void); 221 extern bool cpu_smt_possible(void); 222 extern int cpuhp_smt_enable(void); 223 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval); 224 #else 225 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) 226 static inline void cpu_smt_disable(bool force) { } 227 static inline void cpu_smt_check_topology(void) { } 228 static inline bool cpu_smt_possible(void) { return false; } 229 static inline int cpuhp_smt_enable(void) { return 0; } 230 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; } 231 #endif 232 233 extern bool cpu_mitigations_off(void); 234 extern bool cpu_mitigations_auto_nosmt(void); 235 236 #endif /* _LINUX_CPU_H_ */ 237