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 69 extern __printf(4, 5) 70 struct device *cpu_device_create(struct device *parent, void *drvdata, 71 const struct attribute_group **groups, 72 const char *fmt, ...); 73 #ifdef CONFIG_HOTPLUG_CPU 74 extern void unregister_cpu(struct cpu *cpu); 75 extern ssize_t arch_cpu_probe(const char *, size_t); 76 extern ssize_t arch_cpu_release(const char *, size_t); 77 #endif 78 79 /* 80 * These states are not related to the core CPU hotplug mechanism. They are 81 * used by various (sub)architectures to track internal state 82 */ 83 #define CPU_ONLINE 0x0002 /* CPU is up */ 84 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 85 #define CPU_DEAD 0x0007 /* CPU dead */ 86 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 87 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 88 #define CPU_BROKEN 0x000B /* CPU did not die properly */ 89 90 #ifdef CONFIG_SMP 91 extern bool cpuhp_tasks_frozen; 92 int add_cpu(unsigned int cpu); 93 int cpu_device_up(struct device *dev); 94 void notify_cpu_starting(unsigned int cpu); 95 extern void cpu_maps_update_begin(void); 96 extern void cpu_maps_update_done(void); 97 int bringup_hibernate_cpu(unsigned int sleep_cpu); 98 void bringup_nonboot_cpus(unsigned int setup_max_cpus); 99 100 #else /* CONFIG_SMP */ 101 #define cpuhp_tasks_frozen 0 102 103 static inline void cpu_maps_update_begin(void) 104 { 105 } 106 107 static inline void cpu_maps_update_done(void) 108 { 109 } 110 111 static inline int add_cpu(unsigned int cpu) { return 0;} 112 113 #endif /* CONFIG_SMP */ 114 extern struct bus_type cpu_subsys; 115 116 extern int lockdep_is_cpus_held(void); 117 118 #ifdef CONFIG_HOTPLUG_CPU 119 extern void cpus_write_lock(void); 120 extern void cpus_write_unlock(void); 121 extern void cpus_read_lock(void); 122 extern void cpus_read_unlock(void); 123 extern int cpus_read_trylock(void); 124 extern void lockdep_assert_cpus_held(void); 125 extern void cpu_hotplug_disable(void); 126 extern void cpu_hotplug_enable(void); 127 void clear_tasks_mm_cpumask(int cpu); 128 int remove_cpu(unsigned int cpu); 129 int cpu_device_down(struct device *dev); 130 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); 131 132 #else /* CONFIG_HOTPLUG_CPU */ 133 134 static inline void cpus_write_lock(void) { } 135 static inline void cpus_write_unlock(void) { } 136 static inline void cpus_read_lock(void) { } 137 static inline void cpus_read_unlock(void) { } 138 static inline int cpus_read_trylock(void) { return true; } 139 static inline void lockdep_assert_cpus_held(void) { } 140 static inline void cpu_hotplug_disable(void) { } 141 static inline void cpu_hotplug_enable(void) { } 142 static inline int remove_cpu(unsigned int cpu) { return -EPERM; } 143 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } 144 #endif /* !CONFIG_HOTPLUG_CPU */ 145 146 #ifdef CONFIG_PM_SLEEP_SMP 147 extern int freeze_secondary_cpus(int primary); 148 extern void thaw_secondary_cpus(void); 149 150 static inline int suspend_disable_secondary_cpus(void) 151 { 152 int cpu = 0; 153 154 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 155 cpu = -1; 156 157 return freeze_secondary_cpus(cpu); 158 } 159 static inline void suspend_enable_secondary_cpus(void) 160 { 161 return thaw_secondary_cpus(); 162 } 163 164 #else /* !CONFIG_PM_SLEEP_SMP */ 165 static inline void thaw_secondary_cpus(void) {} 166 static inline int suspend_disable_secondary_cpus(void) { return 0; } 167 static inline void suspend_enable_secondary_cpus(void) { } 168 #endif /* !CONFIG_PM_SLEEP_SMP */ 169 170 void __noreturn cpu_startup_entry(enum cpuhp_state state); 171 172 void cpu_idle_poll_ctrl(bool enable); 173 174 /* Attach to any functions which should be considered cpuidle. */ 175 #define __cpuidle __section(".cpuidle.text") 176 177 bool cpu_in_idle(unsigned long pc); 178 179 void arch_cpu_idle(void); 180 void arch_cpu_idle_prepare(void); 181 void arch_cpu_idle_enter(void); 182 void arch_cpu_idle_exit(void); 183 void arch_cpu_idle_dead(void); 184 185 int cpu_report_state(int cpu); 186 int cpu_check_up_prepare(int cpu); 187 void cpu_set_state_online(int cpu); 188 void play_idle_precise(u64 duration_ns, u64 latency_ns); 189 190 static inline void play_idle(unsigned long duration_us) 191 { 192 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); 193 } 194 195 #ifdef CONFIG_HOTPLUG_CPU 196 bool cpu_wait_death(unsigned int cpu, int seconds); 197 bool cpu_report_death(void); 198 void cpuhp_report_idle_dead(void); 199 #else 200 static inline void cpuhp_report_idle_dead(void) { } 201 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 202 203 enum cpuhp_smt_control { 204 CPU_SMT_ENABLED, 205 CPU_SMT_DISABLED, 206 CPU_SMT_FORCE_DISABLED, 207 CPU_SMT_NOT_SUPPORTED, 208 CPU_SMT_NOT_IMPLEMENTED, 209 }; 210 211 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT) 212 extern enum cpuhp_smt_control cpu_smt_control; 213 extern void cpu_smt_disable(bool force); 214 extern void cpu_smt_check_topology(void); 215 extern bool cpu_smt_possible(void); 216 extern int cpuhp_smt_enable(void); 217 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval); 218 #else 219 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) 220 static inline void cpu_smt_disable(bool force) { } 221 static inline void cpu_smt_check_topology(void) { } 222 static inline bool cpu_smt_possible(void) { return false; } 223 static inline int cpuhp_smt_enable(void) { return 0; } 224 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; } 225 #endif 226 227 extern bool cpu_mitigations_off(void); 228 extern bool cpu_mitigations_auto_nosmt(void); 229 230 #endif /* _LINUX_CPU_H_ */ 231