cpu.h (7608B)
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 22struct device; 23struct device_node; 24struct attribute_group; 25 26struct 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 32extern void boot_cpu_init(void); 33extern void boot_cpu_hotplug_init(void); 34extern void cpu_init(void); 35extern void trap_init(void); 36 37extern int register_cpu(struct cpu *cpu, int num); 38extern struct device *get_cpu_device(unsigned cpu); 39extern bool cpu_is_hotpluggable(unsigned cpu); 40extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id); 41extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun, 42 int cpu, unsigned int *thread); 43 44extern int cpu_add_dev_attr(struct device_attribute *attr); 45extern void cpu_remove_dev_attr(struct device_attribute *attr); 46 47extern int cpu_add_dev_attr_group(struct attribute_group *attrs); 48extern void cpu_remove_dev_attr_group(struct attribute_group *attrs); 49 50extern ssize_t cpu_show_meltdown(struct device *dev, 51 struct device_attribute *attr, char *buf); 52extern ssize_t cpu_show_spectre_v1(struct device *dev, 53 struct device_attribute *attr, char *buf); 54extern ssize_t cpu_show_spectre_v2(struct device *dev, 55 struct device_attribute *attr, char *buf); 56extern ssize_t cpu_show_spec_store_bypass(struct device *dev, 57 struct device_attribute *attr, char *buf); 58extern ssize_t cpu_show_l1tf(struct device *dev, 59 struct device_attribute *attr, char *buf); 60extern ssize_t cpu_show_mds(struct device *dev, 61 struct device_attribute *attr, char *buf); 62extern ssize_t cpu_show_tsx_async_abort(struct device *dev, 63 struct device_attribute *attr, 64 char *buf); 65extern ssize_t cpu_show_itlb_multihit(struct device *dev, 66 struct device_attribute *attr, char *buf); 67extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf); 68extern ssize_t cpu_show_mmio_stale_data(struct device *dev, 69 struct device_attribute *attr, 70 char *buf); 71 72extern __printf(4, 5) 73struct device *cpu_device_create(struct device *parent, void *drvdata, 74 const struct attribute_group **groups, 75 const char *fmt, ...); 76#ifdef CONFIG_HOTPLUG_CPU 77extern void unregister_cpu(struct cpu *cpu); 78extern ssize_t arch_cpu_probe(const char *, size_t); 79extern ssize_t arch_cpu_release(const char *, size_t); 80#endif 81 82/* 83 * These states are not related to the core CPU hotplug mechanism. They are 84 * used by various (sub)architectures to track internal state 85 */ 86#define CPU_ONLINE 0x0002 /* CPU is up */ 87#define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 88#define CPU_DEAD 0x0007 /* CPU dead */ 89#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 90#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 91#define CPU_BROKEN 0x000B /* CPU did not die properly */ 92 93#ifdef CONFIG_SMP 94extern bool cpuhp_tasks_frozen; 95int add_cpu(unsigned int cpu); 96int cpu_device_up(struct device *dev); 97void notify_cpu_starting(unsigned int cpu); 98extern void cpu_maps_update_begin(void); 99extern void cpu_maps_update_done(void); 100int bringup_hibernate_cpu(unsigned int sleep_cpu); 101void bringup_nonboot_cpus(unsigned int setup_max_cpus); 102 103#else /* CONFIG_SMP */ 104#define cpuhp_tasks_frozen 0 105 106static inline void cpu_maps_update_begin(void) 107{ 108} 109 110static inline void cpu_maps_update_done(void) 111{ 112} 113 114static inline int add_cpu(unsigned int cpu) { return 0;} 115 116#endif /* CONFIG_SMP */ 117extern struct bus_type cpu_subsys; 118 119extern int lockdep_is_cpus_held(void); 120 121#ifdef CONFIG_HOTPLUG_CPU 122extern void cpus_write_lock(void); 123extern void cpus_write_unlock(void); 124extern void cpus_read_lock(void); 125extern void cpus_read_unlock(void); 126extern int cpus_read_trylock(void); 127extern void lockdep_assert_cpus_held(void); 128extern void cpu_hotplug_disable(void); 129extern void cpu_hotplug_enable(void); 130void clear_tasks_mm_cpumask(int cpu); 131int remove_cpu(unsigned int cpu); 132int cpu_device_down(struct device *dev); 133extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); 134 135#else /* CONFIG_HOTPLUG_CPU */ 136 137static inline void cpus_write_lock(void) { } 138static inline void cpus_write_unlock(void) { } 139static inline void cpus_read_lock(void) { } 140static inline void cpus_read_unlock(void) { } 141static inline int cpus_read_trylock(void) { return true; } 142static inline void lockdep_assert_cpus_held(void) { } 143static inline void cpu_hotplug_disable(void) { } 144static inline void cpu_hotplug_enable(void) { } 145static inline int remove_cpu(unsigned int cpu) { return -EPERM; } 146static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } 147#endif /* !CONFIG_HOTPLUG_CPU */ 148 149#ifdef CONFIG_PM_SLEEP_SMP 150extern int freeze_secondary_cpus(int primary); 151extern void thaw_secondary_cpus(void); 152 153static inline int suspend_disable_secondary_cpus(void) 154{ 155 int cpu = 0; 156 157 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 158 cpu = -1; 159 160 return freeze_secondary_cpus(cpu); 161} 162static inline void suspend_enable_secondary_cpus(void) 163{ 164 return thaw_secondary_cpus(); 165} 166 167#else /* !CONFIG_PM_SLEEP_SMP */ 168static inline void thaw_secondary_cpus(void) {} 169static inline int suspend_disable_secondary_cpus(void) { return 0; } 170static inline void suspend_enable_secondary_cpus(void) { } 171#endif /* !CONFIG_PM_SLEEP_SMP */ 172 173void __noreturn cpu_startup_entry(enum cpuhp_state state); 174 175void cpu_idle_poll_ctrl(bool enable); 176 177/* Attach to any functions which should be considered cpuidle. */ 178#define __cpuidle __section(".cpuidle.text") 179 180bool cpu_in_idle(unsigned long pc); 181 182void arch_cpu_idle(void); 183void arch_cpu_idle_prepare(void); 184void arch_cpu_idle_enter(void); 185void arch_cpu_idle_exit(void); 186void arch_cpu_idle_dead(void); 187 188int cpu_report_state(int cpu); 189int cpu_check_up_prepare(int cpu); 190void cpu_set_state_online(int cpu); 191void play_idle_precise(u64 duration_ns, u64 latency_ns); 192 193static inline void play_idle(unsigned long duration_us) 194{ 195 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); 196} 197 198#ifdef CONFIG_HOTPLUG_CPU 199bool cpu_wait_death(unsigned int cpu, int seconds); 200bool cpu_report_death(void); 201void cpuhp_report_idle_dead(void); 202#else 203static inline void cpuhp_report_idle_dead(void) { } 204#endif /* #ifdef CONFIG_HOTPLUG_CPU */ 205 206enum cpuhp_smt_control { 207 CPU_SMT_ENABLED, 208 CPU_SMT_DISABLED, 209 CPU_SMT_FORCE_DISABLED, 210 CPU_SMT_NOT_SUPPORTED, 211 CPU_SMT_NOT_IMPLEMENTED, 212}; 213 214#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT) 215extern enum cpuhp_smt_control cpu_smt_control; 216extern void cpu_smt_disable(bool force); 217extern void cpu_smt_check_topology(void); 218extern bool cpu_smt_possible(void); 219extern int cpuhp_smt_enable(void); 220extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval); 221#else 222# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) 223static inline void cpu_smt_disable(bool force) { } 224static inline void cpu_smt_check_topology(void) { } 225static inline bool cpu_smt_possible(void) { return false; } 226static inline int cpuhp_smt_enable(void) { return 0; } 227static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; } 228#endif 229 230extern bool cpu_mitigations_off(void); 231extern bool cpu_mitigations_auto_nosmt(void); 232 233#endif /* _LINUX_CPU_H_ */