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);
  62
  63extern __printf(4, 5)
  64struct device *cpu_device_create(struct device *parent, void *drvdata,
  65                                 const struct attribute_group **groups,
  66                                 const char *fmt, ...);
  67#ifdef CONFIG_HOTPLUG_CPU
  68extern void unregister_cpu(struct cpu *cpu);
  69extern ssize_t arch_cpu_probe(const char *, size_t);
  70extern ssize_t arch_cpu_release(const char *, size_t);
  71#endif
  72
  73/*
  74 * These states are not related to the core CPU hotplug mechanism. They are
  75 * used by various (sub)architectures to track internal state
  76 */
  77#define CPU_ONLINE              0x0002 /* CPU is up */
  78#define CPU_UP_PREPARE          0x0003 /* CPU coming up */
  79#define CPU_DEAD                0x0007 /* CPU dead */
  80#define CPU_DEAD_FROZEN         0x0008 /* CPU timed out on unplug */
  81#define CPU_POST_DEAD           0x0009 /* CPU successfully unplugged */
  82#define CPU_BROKEN              0x000B /* CPU did not die properly */
  83
  84#ifdef CONFIG_SMP
  85extern bool cpuhp_tasks_frozen;
  86int cpu_up(unsigned int cpu);
  87void notify_cpu_starting(unsigned int cpu);
  88extern void cpu_maps_update_begin(void);
  89extern void cpu_maps_update_done(void);
  90
  91#else   /* CONFIG_SMP */
  92#define cpuhp_tasks_frozen      0
  93
  94static inline void cpu_maps_update_begin(void)
  95{
  96}
  97
  98static inline void cpu_maps_update_done(void)
  99{
 100}
 101
 102#endif /* CONFIG_SMP */
 103extern struct bus_type cpu_subsys;
 104
 105#ifdef CONFIG_HOTPLUG_CPU
 106extern void cpus_write_lock(void);
 107extern void cpus_write_unlock(void);
 108extern void cpus_read_lock(void);
 109extern void cpus_read_unlock(void);
 110extern int  cpus_read_trylock(void);
 111extern void lockdep_assert_cpus_held(void);
 112extern void cpu_hotplug_disable(void);
 113extern void cpu_hotplug_enable(void);
 114void clear_tasks_mm_cpumask(int cpu);
 115int cpu_down(unsigned int cpu);
 116
 117#else /* CONFIG_HOTPLUG_CPU */
 118
 119static inline void cpus_write_lock(void) { }
 120static inline void cpus_write_unlock(void) { }
 121static inline void cpus_read_lock(void) { }
 122static inline void cpus_read_unlock(void) { }
 123static inline int  cpus_read_trylock(void) { return true; }
 124static inline void lockdep_assert_cpus_held(void) { }
 125static inline void cpu_hotplug_disable(void) { }
 126static inline void cpu_hotplug_enable(void) { }
 127#endif  /* !CONFIG_HOTPLUG_CPU */
 128
 129/* Wrappers which go away once all code is converted */
 130static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
 131static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
 132static inline void get_online_cpus(void) { cpus_read_lock(); }
 133static inline void put_online_cpus(void) { cpus_read_unlock(); }
 134
 135#ifdef CONFIG_PM_SLEEP_SMP
 136extern int freeze_secondary_cpus(int primary);
 137static inline int disable_nonboot_cpus(void)
 138{
 139        return freeze_secondary_cpus(0);
 140}
 141extern void enable_nonboot_cpus(void);
 142
 143static inline int suspend_disable_secondary_cpus(void)
 144{
 145        int cpu = 0;
 146
 147        if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
 148                cpu = -1;
 149
 150        return freeze_secondary_cpus(cpu);
 151}
 152static inline void suspend_enable_secondary_cpus(void)
 153{
 154        return enable_nonboot_cpus();
 155}
 156
 157#else /* !CONFIG_PM_SLEEP_SMP */
 158static inline int disable_nonboot_cpus(void) { return 0; }
 159static inline void enable_nonboot_cpus(void) {}
 160static inline int suspend_disable_secondary_cpus(void) { return 0; }
 161static inline void suspend_enable_secondary_cpus(void) { }
 162#endif /* !CONFIG_PM_SLEEP_SMP */
 163
 164void cpu_startup_entry(enum cpuhp_state state);
 165
 166void cpu_idle_poll_ctrl(bool enable);
 167
 168/* Attach to any functions which should be considered cpuidle. */
 169#define __cpuidle       __attribute__((__section__(".cpuidle.text")))
 170
 171bool cpu_in_idle(unsigned long pc);
 172
 173void arch_cpu_idle(void);
 174void arch_cpu_idle_prepare(void);
 175void arch_cpu_idle_enter(void);
 176void arch_cpu_idle_exit(void);
 177void arch_cpu_idle_dead(void);
 178
 179int cpu_report_state(int cpu);
 180int cpu_check_up_prepare(int cpu);
 181void cpu_set_state_online(int cpu);
 182void play_idle(unsigned long duration_ms);
 183
 184#ifdef CONFIG_HOTPLUG_CPU
 185bool cpu_wait_death(unsigned int cpu, int seconds);
 186bool cpu_report_death(void);
 187void cpuhp_report_idle_dead(void);
 188#else
 189static inline void cpuhp_report_idle_dead(void) { }
 190#endif /* #ifdef CONFIG_HOTPLUG_CPU */
 191
 192enum cpuhp_smt_control {
 193        CPU_SMT_ENABLED,
 194        CPU_SMT_DISABLED,
 195        CPU_SMT_FORCE_DISABLED,
 196        CPU_SMT_NOT_SUPPORTED,
 197        CPU_SMT_NOT_IMPLEMENTED,
 198};
 199
 200#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
 201extern enum cpuhp_smt_control cpu_smt_control;
 202extern void cpu_smt_disable(bool force);
 203extern void cpu_smt_check_topology(void);
 204extern int cpuhp_smt_enable(void);
 205extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
 206#else
 207# define cpu_smt_control                (CPU_SMT_NOT_IMPLEMENTED)
 208static inline void cpu_smt_disable(bool force) { }
 209static inline void cpu_smt_check_topology(void) { }
 210static inline int cpuhp_smt_enable(void) { return 0; }
 211static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
 212#endif
 213
 214/*
 215 * These are used for a global "mitigations=" cmdline option for toggling
 216 * optional CPU mitigations.
 217 */
 218enum cpu_mitigations {
 219        CPU_MITIGATIONS_OFF,
 220        CPU_MITIGATIONS_AUTO,
 221        CPU_MITIGATIONS_AUTO_NOSMT,
 222};
 223
 224extern enum cpu_mitigations cpu_mitigations;
 225
 226/* mitigations=off */
 227static inline bool cpu_mitigations_off(void)
 228{
 229        return cpu_mitigations == CPU_MITIGATIONS_OFF;
 230}
 231
 232/* mitigations=auto,nosmt */
 233static inline bool cpu_mitigations_auto_nosmt(void)
 234{
 235        return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
 236}
 237
 238#endif /* _LINUX_CPU_H_ */
 239