LXR linux/include/linux/cpu.h

   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);
  68
  69extern __printf(4, 5)
  70struct device *cpu_device_create(struct device *parent, void *drvdata,
  71                                 const struct attribute_group **groups,
  72                                 const char *fmt, ...);
  73#ifdef CONFIG_HOTPLUG_CPU
  74extern void unregister_cpu(struct cpu *cpu);
  75extern ssize_t arch_cpu_probe(const char *, size_t);
  76extern 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
  91extern bool cpuhp_tasks_frozen;
  92int add_cpu(unsigned int cpu);
  93int cpu_device_up(struct device *dev);
  94void notify_cpu_starting(unsigned int cpu);
  95extern void cpu_maps_update_begin(void);
  96extern void cpu_maps_update_done(void);
  97int bringup_hibernate_cpu(unsigned int sleep_cpu);
  98void bringup_nonboot_cpus(unsigned int setup_max_cpus);
  99
 100#else   /* CONFIG_SMP */
 101#define cpuhp_tasks_frozen      0
 102
 103static inline void cpu_maps_update_begin(void)
 104{
 105}
 106
 107static inline void cpu_maps_update_done(void)
 108{
 109}
 110
 111static inline int add_cpu(unsigned int cpu) { return 0;}
 112
 113#endif /* CONFIG_SMP */
 114extern struct bus_type cpu_subsys;
 115
 116extern int lockdep_is_cpus_held(void);
 117
 118#ifdef CONFIG_HOTPLUG_CPU
 119extern void cpus_write_lock(void);
 120extern void cpus_write_unlock(void);
 121extern void cpus_read_lock(void);
 122extern void cpus_read_unlock(void);
 123extern int  cpus_read_trylock(void);
 124extern void lockdep_assert_cpus_held(void);
 125extern void cpu_hotplug_disable(void);
 126extern void cpu_hotplug_enable(void);
 127void clear_tasks_mm_cpumask(int cpu);
 128int remove_cpu(unsigned int cpu);
 129int cpu_device_down(struct device *dev);
 130extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
 131
 132#else /* CONFIG_HOTPLUG_CPU */
 133
 134static inline void cpus_write_lock(void) { }
 135static inline void cpus_write_unlock(void) { }
 136static inline void cpus_read_lock(void) { }
 137static inline void cpus_read_unlock(void) { }
 138static inline int  cpus_read_trylock(void) { return true; }
 139static inline void lockdep_assert_cpus_held(void) { }
 140static inline void cpu_hotplug_disable(void) { }
 141static inline void cpu_hotplug_enable(void) { }
 142static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
 143static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
 144#endif  /* !CONFIG_HOTPLUG_CPU */
 145
 146#ifdef CONFIG_PM_SLEEP_SMP
 147extern int freeze_secondary_cpus(int primary);
 148extern void thaw_secondary_cpus(void);
 149
 150static 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}
 159static inline void suspend_enable_secondary_cpus(void)
 160{
 161        return thaw_secondary_cpus();
 162}
 163
 164#else /* !CONFIG_PM_SLEEP_SMP */
 165static inline void thaw_secondary_cpus(void) {}
 166static inline int suspend_disable_secondary_cpus(void) { return 0; }
 167static inline void suspend_enable_secondary_cpus(void) { }
 168#endif /* !CONFIG_PM_SLEEP_SMP */
 169
 170void cpu_startup_entry(enum cpuhp_state state);
 171
 172void cpu_idle_poll_ctrl(bool enable);
 173
 174/* Attach to any functions which should be considered cpuidle. */
 175#define __cpuidle       __section(".cpuidle.text")
 176
 177bool cpu_in_idle(unsigned long pc);
 178
 179void arch_cpu_idle(void);
 180void arch_cpu_idle_prepare(void);
 181void arch_cpu_idle_enter(void);
 182void arch_cpu_idle_exit(void);
 183void arch_cpu_idle_dead(void);
 184
 185int cpu_report_state(int cpu);
 186int cpu_check_up_prepare(int cpu);
 187void cpu_set_state_online(int cpu);
 188void play_idle_precise(u64 duration_ns, u64 latency_ns);
 189
 190static 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
 196bool cpu_wait_death(unsigned int cpu, int seconds);
 197bool cpu_report_death(void);
 198void cpuhp_report_idle_dead(void);
 199#else
 200static inline void cpuhp_report_idle_dead(void) { }
 201#endif /* #ifdef CONFIG_HOTPLUG_CPU */
 202
 203enum 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)
 212extern enum cpuhp_smt_control cpu_smt_control;
 213extern void cpu_smt_disable(bool force);
 214extern void cpu_smt_check_topology(void);
 215extern bool cpu_smt_possible(void);
 216extern int cpuhp_smt_enable(void);
 217extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
 218#else
 219# define cpu_smt_control                (CPU_SMT_NOT_IMPLEMENTED)
 220static inline void cpu_smt_disable(bool force) { }
 221static inline void cpu_smt_check_topology(void) { }
 222static inline bool cpu_smt_possible(void) { return false; }
 223static inline int cpuhp_smt_enable(void) { return 0; }
 224static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
 225#endif
 226
 227extern bool cpu_mitigations_off(void);
 228extern bool cpu_mitigations_auto_nosmt(void);
 229
 230#endif /* _LINUX_CPU_H_ */
 231