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/cpuhplock.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 extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev, 79 struct device_attribute *attr, char *buf); 80 extern ssize_t cpu_show_ghostwrite(struct device *dev, struct device_attribute *attr, char *buf); 81 extern ssize_t cpu_show_old_microcode(struct device *dev, 82 struct device_attribute *attr, char *buf); 83 extern ssize_t cpu_show_indirect_target_selection(struct device *dev, 84 struct device_attribute *attr, char *buf); 85 extern ssize_t cpu_show_tsa(struct device *dev, struct device_attribute *attr, char *buf); 86 extern ssize_t cpu_show_vmscape(struct device *dev, struct device_attribute *attr, char *buf); 87 88 extern __printf(4, 5) 89 struct device *cpu_device_create(struct device *parent, void *drvdata, 90 const struct attribute_group **groups, 91 const char *fmt, ...); 92 extern bool arch_cpu_is_hotpluggable(int cpu); 93 extern int arch_register_cpu(int cpu); 94 extern void arch_unregister_cpu(int cpu); 95 #ifdef CONFIG_HOTPLUG_CPU 96 extern void unregister_cpu(struct cpu *cpu); 97 extern ssize_t arch_cpu_probe(const char *, size_t); 98 extern ssize_t arch_cpu_release(const char *, size_t); 99 #endif 100 101 #ifdef CONFIG_GENERIC_CPU_DEVICES 102 DECLARE_PER_CPU(struct cpu, cpu_devices); 103 #endif 104 105 /* 106 * These states are not related to the core CPU hotplug mechanism. They are 107 * used by various (sub)architectures to track internal state 108 */ 109 #define CPU_ONLINE 0x0002 /* CPU is up */ 110 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 111 #define CPU_DEAD 0x0007 /* CPU dead */ 112 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 113 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 114 #define CPU_BROKEN 0x000B /* CPU did not die properly */ 115 116 #ifdef CONFIG_SMP 117 extern bool cpuhp_tasks_frozen; 118 int add_cpu(unsigned int cpu); 119 int cpu_device_up(struct device *dev); 120 void notify_cpu_starting(unsigned int cpu); 121 extern void cpu_maps_update_begin(void); 122 extern void cpu_maps_update_done(void); 123 int bringup_hibernate_cpu(unsigned int sleep_cpu); 124 void bringup_nonboot_cpus(unsigned int max_cpus); 125 int arch_cpu_rescan_dead_smt_siblings(void); 126 127 #else /* CONFIG_SMP */ 128 #define cpuhp_tasks_frozen 0 129 130 static inline void cpu_maps_update_begin(void) 131 { 132 } 133 134 static inline void cpu_maps_update_done(void) 135 { 136 } 137 138 static inline int add_cpu(unsigned int cpu) { return 0;} 139 140 static inline int arch_cpu_rescan_dead_smt_siblings(void) { return 0; } 141 142 #endif /* CONFIG_SMP */ 143 extern const struct bus_type cpu_subsys; 144 145 #ifdef CONFIG_PM_SLEEP_SMP 146 extern int freeze_secondary_cpus(int primary); 147 extern void thaw_secondary_cpus(void); 148 149 static inline int suspend_disable_secondary_cpus(void) 150 { 151 int cpu = 0; 152 153 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 154 cpu = -1; 155 156 return freeze_secondary_cpus(cpu); 157 } 158 static inline void suspend_enable_secondary_cpus(void) 159 { 160 thaw_secondary_cpus(); 161 } 162 163 #else /* !CONFIG_PM_SLEEP_SMP */ 164 static inline void thaw_secondary_cpus(void) {} 165 static inline int suspend_disable_secondary_cpus(void) { return 0; } 166 static inline void suspend_enable_secondary_cpus(void) { } 167 #endif /* !CONFIG_PM_SLEEP_SMP */ 168 169 void __noreturn cpu_startup_entry(enum cpuhp_state state); 170 171 void cpu_idle_poll_ctrl(bool enable); 172 173 bool cpu_in_idle(unsigned long pc); 174 175 void arch_cpu_idle(void); 176 void arch_cpu_idle_prepare(void); 177 void arch_cpu_idle_enter(void); 178 void arch_cpu_idle_exit(void); 179 void arch_tick_broadcast_enter(void); 180 void arch_tick_broadcast_exit(void); 181 void __noreturn arch_cpu_idle_dead(void); 182 183 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT 184 void arch_cpu_finalize_init(void); 185 #else 186 static inline void arch_cpu_finalize_init(void) { } 187 #endif 188 189 void play_idle_precise(u64 duration_ns, u64 latency_ns); 190 191 #ifdef CONFIG_HOTPLUG_CPU 192 void cpuhp_report_idle_dead(void); 193 #else 194 static inline void cpuhp_report_idle_dead(void) { } 195 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 196 197 enum cpu_attack_vectors { 198 CPU_MITIGATE_USER_KERNEL, 199 CPU_MITIGATE_USER_USER, 200 CPU_MITIGATE_GUEST_HOST, 201 CPU_MITIGATE_GUEST_GUEST, 202 NR_CPU_ATTACK_VECTORS, 203 }; 204 205 enum smt_mitigations { 206 SMT_MITIGATIONS_OFF, 207 SMT_MITIGATIONS_AUTO, 208 SMT_MITIGATIONS_ON, 209 }; 210 211 #ifdef CONFIG_CPU_MITIGATIONS 212 extern bool cpu_mitigations_off(void); 213 extern bool cpu_mitigations_auto_nosmt(void); 214 extern bool cpu_attack_vector_mitigated(enum cpu_attack_vectors v); 215 extern enum smt_mitigations smt_mitigations; 216 #else 217 static inline bool cpu_mitigations_off(void) 218 { 219 return true; 220 } 221 static inline bool cpu_mitigations_auto_nosmt(void) 222 { 223 return false; 224 } 225 static inline bool cpu_attack_vector_mitigated(enum cpu_attack_vectors v) 226 { 227 return false; 228 } 229 #define smt_mitigations SMT_MITIGATIONS_OFF 230 #endif 231 232 int arch_get_indir_br_lp_status(struct task_struct *t, unsigned long __user *status); 233 int arch_set_indir_br_lp_status(struct task_struct *t, unsigned long status); 234 int arch_lock_indir_br_lp_status(struct task_struct *t, unsigned long status); 235 236 #endif /* _LINUX_CPU_H_ */ 237