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);
  60
  61extern __printf(4, 5)
  62struct device *cpu_device_create(struct device *parent, void *drvdata,
  63                                 const struct attribute_group **groups,
  64                                 const char *fmt, ...);
  65#ifdef CONFIG_HOTPLUG_CPU
  66extern void unregister_cpu(struct cpu *cpu);
  67extern ssize_t arch_cpu_probe(const char *, size_t);
  68extern ssize_t arch_cpu_release(const char *, size_t);
  69#endif
  70
  71/*
  72 * These states are not related to the core CPU hotplug mechanism. They are
  73 * used by various (sub)architectures to track internal state
  74 */
  75#define CPU_ONLINE              0x0002 /* CPU is up */
  76#define CPU_UP_PREPARE          0x0003 /* CPU coming up */
  77#define CPU_DEAD                0x0007 /* CPU dead */
  78#define CPU_DEAD_FROZEN         0x0008 /* CPU timed out on unplug */
  79#define CPU_POST_DEAD           0x0009 /* CPU successfully unplugged */
  80#define CPU_BROKEN              0x000B /* CPU did not die properly */
  81
  82#ifdef CONFIG_SMP
  83extern bool cpuhp_tasks_frozen;
  84int cpu_up(unsigned int cpu);
  85void notify_cpu_starting(unsigned int cpu);
  86extern void cpu_maps_update_begin(void);
  87extern void cpu_maps_update_done(void);
  88
  89#else   /* CONFIG_SMP */
  90#define cpuhp_tasks_frozen      0
  91
  92static inline void cpu_maps_update_begin(void)
  93{
  94}
  95
  96static inline void cpu_maps_update_done(void)
  97{
  98}
  99
 100#endif /* CONFIG_SMP */
 101extern struct bus_type cpu_subsys;
 102
 103#ifdef CONFIG_HOTPLUG_CPU
 104extern void cpus_write_lock(void);
 105extern void cpus_write_unlock(void);
 106extern void cpus_read_lock(void);
 107extern void cpus_read_unlock(void);
 108extern int  cpus_read_trylock(void);
 109extern void lockdep_assert_cpus_held(void);
 110extern void cpu_hotplug_disable(void);
 111extern void cpu_hotplug_enable(void);
 112void clear_tasks_mm_cpumask(int cpu);
 113int cpu_down(unsigned int cpu);
 114
 115#else /* CONFIG_HOTPLUG_CPU */
 116
 117static inline void cpus_write_lock(void) { }
 118static inline void cpus_write_unlock(void) { }
 119static inline void cpus_read_lock(void) { }
 120static inline void cpus_read_unlock(void) { }
 121static inline int  cpus_read_trylock(void) { return true; }
 122static inline void lockdep_assert_cpus_held(void) { }
 123static inline void cpu_hotplug_disable(void) { }
 124static inline void cpu_hotplug_enable(void) { }
 125#endif  /* !CONFIG_HOTPLUG_CPU */
 126
 127/* Wrappers which go away once all code is converted */
 128static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
 129static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
 130static inline void get_online_cpus(void) { cpus_read_lock(); }
 131static inline void put_online_cpus(void) { cpus_read_unlock(); }
 132
 133#ifdef CONFIG_PM_SLEEP_SMP
 134extern int freeze_secondary_cpus(int primary);
 135static inline int disable_nonboot_cpus(void)
 136{
 137        return freeze_secondary_cpus(0);
 138}
 139extern void enable_nonboot_cpus(void);
 140#else /* !CONFIG_PM_SLEEP_SMP */
 141static inline int disable_nonboot_cpus(void) { return 0; }
 142static inline void enable_nonboot_cpus(void) {}
 143#endif /* !CONFIG_PM_SLEEP_SMP */
 144
 145void cpu_startup_entry(enum cpuhp_state state);
 146
 147void cpu_idle_poll_ctrl(bool enable);
 148
 149/* Attach to any functions which should be considered cpuidle. */
 150#define __cpuidle       __attribute__((__section__(".cpuidle.text")))
 151
 152bool cpu_in_idle(unsigned long pc);
 153
 154void arch_cpu_idle(void);
 155void arch_cpu_idle_prepare(void);
 156void arch_cpu_idle_enter(void);
 157void arch_cpu_idle_exit(void);
 158void arch_cpu_idle_dead(void);
 159
 160int cpu_report_state(int cpu);
 161int cpu_check_up_prepare(int cpu);
 162void cpu_set_state_online(int cpu);
 163void play_idle(unsigned long duration_ms);
 164
 165#ifdef CONFIG_HOTPLUG_CPU
 166bool cpu_wait_death(unsigned int cpu, int seconds);
 167bool cpu_report_death(void);
 168void cpuhp_report_idle_dead(void);
 169#else
 170static inline void cpuhp_report_idle_dead(void) { }
 171#endif /* #ifdef CONFIG_HOTPLUG_CPU */
 172
 173enum cpuhp_smt_control {
 174        CPU_SMT_ENABLED,
 175        CPU_SMT_DISABLED,
 176        CPU_SMT_FORCE_DISABLED,
 177        CPU_SMT_NOT_SUPPORTED,
 178};
 179
 180#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
 181extern enum cpuhp_smt_control cpu_smt_control;
 182extern void cpu_smt_disable(bool force);
 183extern void cpu_smt_check_topology(void);
 184#else
 185# define cpu_smt_control                (CPU_SMT_ENABLED)
 186static inline void cpu_smt_disable(bool force) { }
 187static inline void cpu_smt_check_topology(void) { }
 188#endif
 189
 190#endif /* _LINUX_CPU_H_ */
 191