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 23struct device; 24struct device_node; 25struct attribute_group; 26 27struct 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 33extern void boot_cpu_init(void); 34extern void boot_cpu_hotplug_init(void); 35extern void cpu_init(void); 36extern void trap_init(void); 37 38extern int register_cpu(struct cpu *cpu, int num); 39extern struct device *get_cpu_device(unsigned cpu); 40extern bool cpu_is_hotpluggable(unsigned cpu); 41extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id); 42extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun, 43 int cpu, unsigned int *thread); 44 45extern int cpu_add_dev_attr(struct device_attribute *attr); 46extern void cpu_remove_dev_attr(struct device_attribute *attr); 47 48extern int cpu_add_dev_attr_group(struct attribute_group *attrs); 49extern void cpu_remove_dev_attr_group(struct attribute_group *attrs); 50 51extern ssize_t cpu_show_meltdown(struct device *dev, 52 struct device_attribute *attr, char *buf); 53extern ssize_t cpu_show_spectre_v1(struct device *dev, 54 struct device_attribute *attr, char *buf); 55extern ssize_t cpu_show_spectre_v2(struct device *dev, 56 struct device_attribute *attr, char *buf); 57extern ssize_t cpu_show_spec_store_bypass(struct device *dev, 58 struct device_attribute *attr, char *buf); 59extern ssize_t cpu_show_l1tf(struct device *dev, 60 struct device_attribute *attr, char *buf); 61extern ssize_t cpu_show_mds(struct device *dev, 62 struct device_attribute *attr, char *buf); 63extern ssize_t cpu_show_tsx_async_abort(struct device *dev, 64 struct device_attribute *attr, 65 char *buf); 66extern ssize_t cpu_show_itlb_multihit(struct device *dev, 67 struct device_attribute *attr, char *buf); 68extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf); 69extern ssize_t cpu_show_mmio_stale_data(struct device *dev, 70 struct device_attribute *attr, 71 char *buf); 72extern ssize_t cpu_show_retbleed(struct device *dev, 73 struct device_attribute *attr, char *buf); 74extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev, 75 struct device_attribute *attr, char *buf); 76extern ssize_t cpu_show_gds(struct device *dev, 77 struct device_attribute *attr, char *buf); 78extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev, 79 struct device_attribute *attr, char *buf); 80 81extern __printf(4, 5) 82struct device *cpu_device_create(struct device *parent, void *drvdata, 83 const struct attribute_group **groups, 84 const char *fmt, ...); 85extern bool arch_cpu_is_hotpluggable(int cpu); 86extern int arch_register_cpu(int cpu); 87extern void arch_unregister_cpu(int cpu); 88#ifdef CONFIG_HOTPLUG_CPU 89extern void unregister_cpu(struct cpu *cpu); 90extern ssize_t arch_cpu_probe(const char *, size_t); 91extern ssize_t arch_cpu_release(const char *, size_t); 92#endif 93 94#ifdef CONFIG_GENERIC_CPU_DEVICES 95DECLARE_PER_CPU(struct cpu, cpu_devices); 96#endif 97 98/* 99 * These states are not related to the core CPU hotplug mechanism. They are 100 * used by various (sub)architectures to track internal state 101 */ 102#define CPU_ONLINE 0x0002 /* CPU is up */ 103#define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 104#define CPU_DEAD 0x0007 /* CPU dead */ 105#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 106#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 107#define CPU_BROKEN 0x000B /* CPU did not die properly */ 108 109#ifdef CONFIG_SMP 110extern bool cpuhp_tasks_frozen; 111int add_cpu(unsigned int cpu); 112int cpu_device_up(struct device *dev); 113void notify_cpu_starting(unsigned int cpu); 114extern void cpu_maps_update_begin(void); 115extern void cpu_maps_update_done(void); 116int bringup_hibernate_cpu(unsigned int sleep_cpu); 117void bringup_nonboot_cpus(unsigned int max_cpus); 118 119#else /* CONFIG_SMP */ 120#define cpuhp_tasks_frozen 0 121 122static inline void cpu_maps_update_begin(void) 123{ 124} 125 126static inline void cpu_maps_update_done(void) 127{ 128} 129 130static inline int add_cpu(unsigned int cpu) { return 0;} 131 132#endif /* CONFIG_SMP */ 133extern const struct bus_type cpu_subsys; 134 135extern int lockdep_is_cpus_held(void); 136 137#ifdef CONFIG_HOTPLUG_CPU 138extern void cpus_write_lock(void); 139extern void cpus_write_unlock(void); 140extern void cpus_read_lock(void); 141extern void cpus_read_unlock(void); 142extern int cpus_read_trylock(void); 143extern void lockdep_assert_cpus_held(void); 144extern void cpu_hotplug_disable(void); 145extern void cpu_hotplug_enable(void); 146void clear_tasks_mm_cpumask(int cpu); 147int remove_cpu(unsigned int cpu); 148int cpu_device_down(struct device *dev); 149extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); 150 151#else /* CONFIG_HOTPLUG_CPU */ 152 153static inline void cpus_write_lock(void) { } 154static inline void cpus_write_unlock(void) { } 155static inline void cpus_read_lock(void) { } 156static inline void cpus_read_unlock(void) { } 157static inline int cpus_read_trylock(void) { return true; } 158static inline void lockdep_assert_cpus_held(void) { } 159static inline void cpu_hotplug_disable(void) { } 160static inline void cpu_hotplug_enable(void) { } 161static inline int remove_cpu(unsigned int cpu) { return -EPERM; } 162static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } 163#endif /* !CONFIG_HOTPLUG_CPU */ 164 165DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock()) 166 167#ifdef CONFIG_PM_SLEEP_SMP 168extern int freeze_secondary_cpus(int primary); 169extern void thaw_secondary_cpus(void); 170 171static inline int suspend_disable_secondary_cpus(void) 172{ 173 int cpu = 0; 174 175 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 176 cpu = -1; 177 178 return freeze_secondary_cpus(cpu); 179} 180static inline void suspend_enable_secondary_cpus(void) 181{ 182 return thaw_secondary_cpus(); 183} 184 185#else /* !CONFIG_PM_SLEEP_SMP */ 186static inline void thaw_secondary_cpus(void) {} 187static inline int suspend_disable_secondary_cpus(void) { return 0; } 188static inline void suspend_enable_secondary_cpus(void) { } 189#endif /* !CONFIG_PM_SLEEP_SMP */ 190 191void __noreturn cpu_startup_entry(enum cpuhp_state state); 192 193void cpu_idle_poll_ctrl(bool enable); 194 195bool cpu_in_idle(unsigned long pc); 196 197void arch_cpu_idle(void); 198void arch_cpu_idle_prepare(void); 199void arch_cpu_idle_enter(void); 200void arch_cpu_idle_exit(void); 201void arch_tick_broadcast_enter(void); 202void arch_tick_broadcast_exit(void); 203void __noreturn arch_cpu_idle_dead(void); 204 205#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT 206void arch_cpu_finalize_init(void); 207#else 208static inline void arch_cpu_finalize_init(void) { } 209#endif 210 211void play_idle_precise(u64 duration_ns, u64 latency_ns); 212 213static inline void play_idle(unsigned long duration_us) 214{ 215 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); 216} 217 218#ifdef CONFIG_HOTPLUG_CPU 219void cpuhp_report_idle_dead(void); 220#else 221static inline void cpuhp_report_idle_dead(void) { } 222#endif /* #ifdef CONFIG_HOTPLUG_CPU */ 223 224extern bool cpu_mitigations_off(void); 225extern bool cpu_mitigations_auto_nosmt(void); 226 227#endif /* _LINUX_CPU_H_ */ 228