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
  22 struct device;
  23 struct device_node;
  24 struct attribute_group;
  25
  26 struct 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
  32 extern void boot_cpu_init(void);
  33 extern void boot_cpu_hotplug_init(void);
  34 extern void cpu_init(void);
  35 extern void trap_init(void);
  36
  37 extern int register_cpu(struct cpu *cpu, int num);
  38 extern struct device *get_cpu_device(unsigned cpu);
  39 extern bool cpu_is_hotpluggable(unsigned cpu);
  40 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
  41 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
  42                                               int cpu, unsigned int *thread);
  43
  44 extern int cpu_add_dev_attr(struct device_attribute *attr);
  45 extern void cpu_remove_dev_attr(struct device_attribute *attr);
  46
  47 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  48 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  49
  50 extern ssize_t cpu_show_meltdown(struct device *dev,
  51                                  struct device_attribute *attr, char *buf);
  52 extern ssize_t cpu_show_spectre_v1(struct device *dev,
  53                                    struct device_attribute *attr, char *buf);
  54 extern ssize_t cpu_show_spectre_v2(struct device *dev,
  55                                    struct device_attribute *attr, char *buf);
  56 extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
  57                                           struct device_attribute *attr, char *buf);
  58 extern ssize_t cpu_show_l1tf(struct device *dev,
  59                              struct device_attribute *attr, char *buf);
  60 extern ssize_t cpu_show_mds(struct device *dev,
  61                             struct device_attribute *attr, char *buf);
  62
  63 extern __printf(4, 5)
  64 struct device *cpu_device_create(struct device *parent, void *drvdata,
  65                                  const struct attribute_group **groups,
  66                                  const char *fmt, ...);
  67 #ifdef CONFIG_HOTPLUG_CPU
  68 extern void unregister_cpu(struct cpu *cpu);
  69 extern ssize_t arch_cpu_probe(const char *, size_t);
  70 extern 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
  85 extern bool cpuhp_tasks_frozen;
  86 int cpu_up(unsigned int cpu);
  87 void notify_cpu_starting(unsigned int cpu);
  88 extern void cpu_maps_update_begin(void);
  89 extern void cpu_maps_update_done(void);
  90
  91 #else   /* CONFIG_SMP */
  92 #define cpuhp_tasks_frozen      0
  93
  94 static inline void cpu_maps_update_begin(void)
  95 {
  96 }
  97
  98 static inline void cpu_maps_update_done(void)
  99 {
 100 }
 101
 102 #endif /* CONFIG_SMP */
 103 extern struct bus_type cpu_subsys;
 104
 105 #ifdef CONFIG_HOTPLUG_CPU
 106 extern void cpus_write_lock(void);
 107 extern void cpus_write_unlock(void);
 108 extern void cpus_read_lock(void);
 109 extern void cpus_read_unlock(void);
 110 extern void lockdep_assert_cpus_held(void);
 111 extern void cpu_hotplug_disable(void);
 112 extern void cpu_hotplug_enable(void);
 113 void clear_tasks_mm_cpumask(int cpu);
 114 int cpu_down(unsigned int cpu);
 115
 116 #else /* CONFIG_HOTPLUG_CPU */
 117
 118 static inline void cpus_write_lock(void) { }
 119 static inline void cpus_write_unlock(void) { }
 120 static inline void cpus_read_lock(void) { }
 121 static inline void cpus_read_unlock(void) { }
 122 static inline void lockdep_assert_cpus_held(void) { }
 123 static inline void cpu_hotplug_disable(void) { }
 124 static inline void cpu_hotplug_enable(void) { }
 125 #endif  /* !CONFIG_HOTPLUG_CPU */
 126
 127 /* Wrappers which go away once all code is converted */
 128 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
 129 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
 130 static inline void get_online_cpus(void) { cpus_read_lock(); }
 131 static inline void put_online_cpus(void) { cpus_read_unlock(); }
 132
 133 #ifdef CONFIG_PM_SLEEP_SMP
 134 extern int freeze_secondary_cpus(int primary);
 135 static inline int disable_nonboot_cpus(void)
 136 {
 137         return freeze_secondary_cpus(0);
 138 }
 139 extern void enable_nonboot_cpus(void);
 140 #else /* !CONFIG_PM_SLEEP_SMP */
 141 static inline int disable_nonboot_cpus(void) { return 0; }
 142 static inline void enable_nonboot_cpus(void) {}
 143 #endif /* !CONFIG_PM_SLEEP_SMP */
 144
 145 void cpu_startup_entry(enum cpuhp_state state);
 146
 147 void 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
 152 bool cpu_in_idle(unsigned long pc);
 153
 154 void arch_cpu_idle(void);
 155 void arch_cpu_idle_prepare(void);
 156 void arch_cpu_idle_enter(void);
 157 void arch_cpu_idle_exit(void);
 158 void arch_cpu_idle_dead(void);
 159
 160 int cpu_report_state(int cpu);
 161 int cpu_check_up_prepare(int cpu);
 162 void cpu_set_state_online(int cpu);
 163 void play_idle(unsigned long duration_ms);
 164
 165 #ifdef CONFIG_HOTPLUG_CPU
 166 bool cpu_wait_death(unsigned int cpu, int seconds);
 167 bool cpu_report_death(void);
 168 void cpuhp_report_idle_dead(void);
 169 #else
 170 static inline void cpuhp_report_idle_dead(void) { }
 171 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
 172
 173 enum 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)
 181 extern enum cpuhp_smt_control cpu_smt_control;
 182 extern void cpu_smt_disable(bool force);
 183 extern void cpu_smt_check_topology(void);
 184 extern int cpuhp_smt_enable(void);
 185 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
 186 #else
 187 # define cpu_smt_control                (CPU_SMT_ENABLED)
 188 static inline void cpu_smt_disable(bool force) { }
 189 static inline void cpu_smt_check_topology(void) { }
 190 static inline int cpuhp_smt_enable(void) { return 0; }
 191 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
 192 #endif
 193
 194 /*
 195  * These are used for a global "mitigations=" cmdline option for toggling
 196  * optional CPU mitigations.
 197  */
 198 enum cpu_mitigations {
 199         CPU_MITIGATIONS_OFF,
 200         CPU_MITIGATIONS_AUTO,
 201         CPU_MITIGATIONS_AUTO_NOSMT,
 202 };
 203
 204 extern enum cpu_mitigations cpu_mitigations;
 205
 206 /* mitigations=off */
 207 static inline bool cpu_mitigations_off(void)
 208 {
 209         return cpu_mitigations == CPU_MITIGATIONS_OFF;
 210 }
 211
 212 /* mitigations=auto,nosmt */
 213 static inline bool cpu_mitigations_auto_nosmt(void)
 214 {
 215         return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
 216 }
 217
 218 #endif /* _LINUX_CPU_H_ */