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/cpuhotplug.h>
  20 #include <linux/cpuhplock.h>
  21 #include <linux/cpu_smt.h>
  22
  23 struct device;
  24 struct device_node;
  25 struct attribute_group;
  26
  27 struct cpu {
  28         int node_id;            /* The node which contains the CPU */
  29         int hotpluggable;       /* creates sysfs control file if hotpluggable */
  30         struct device dev;
  31 };
  32
  33 extern void boot_cpu_init(void);
  34 extern void boot_cpu_hotplug_init(void);
  35 extern void cpu_init(void);
  36 extern void trap_init(void);
  37
  38 extern int register_cpu(struct cpu *cpu, int num);
  39 extern struct device *get_cpu_device(unsigned cpu);
  40 extern bool cpu_is_hotpluggable(unsigned cpu);
  41 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
  42 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
  43                                               int cpu, unsigned int *thread);
  44
  45 extern int cpu_add_dev_attr(struct device_attribute *attr);
  46 extern void cpu_remove_dev_attr(struct device_attribute *attr);
  47
  48 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  49 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
  50
  51 extern ssize_t cpu_show_meltdown(struct device *dev,
  52                                  struct device_attribute *attr, char *buf);
  53 extern ssize_t cpu_show_spectre_v1(struct device *dev,
  54                                    struct device_attribute *attr, char *buf);
  55 extern ssize_t cpu_show_spectre_v2(struct device *dev,
  56                                    struct device_attribute *attr, char *buf);
  57 extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
  58                                           struct device_attribute *attr, char *buf);
  59 extern ssize_t cpu_show_l1tf(struct device *dev,
  60                              struct device_attribute *attr, char *buf);
  61 extern ssize_t cpu_show_mds(struct device *dev,
  62                             struct device_attribute *attr, char *buf);
  63 extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
  64                                         struct device_attribute *attr,
  65                                         char *buf);
  66 extern ssize_t cpu_show_itlb_multihit(struct device *dev,
  67                                       struct device_attribute *attr, char *buf);
  68 extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
  69 extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
  70                                         struct device_attribute *attr,
  71                                         char *buf);
  72 extern ssize_t cpu_show_retbleed(struct device *dev,
  73                                  struct device_attribute *attr, char *buf);
  74 extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev,
  75                                              struct device_attribute *attr, char *buf);
  76 extern ssize_t cpu_show_gds(struct device *dev,
  77                             struct device_attribute *attr, char *buf);
  78 extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev,
  79                                                struct device_attribute *attr, char *buf);
  80
  81 extern __printf(4, 5)
  82 struct device *cpu_device_create(struct device *parent, void *drvdata,
  83                                  const struct attribute_group **groups,
  84                                  const char *fmt, ...);
  85 extern bool arch_cpu_is_hotpluggable(int cpu);
  86 extern int arch_register_cpu(int cpu);
  87 extern void arch_unregister_cpu(int cpu);
  88 #ifdef CONFIG_HOTPLUG_CPU
  89 extern void unregister_cpu(struct cpu *cpu);
  90 extern ssize_t arch_cpu_probe(const char *, size_t);
  91 extern ssize_t arch_cpu_release(const char *, size_t);
  92 #endif
  93
  94 #ifdef CONFIG_GENERIC_CPU_DEVICES
  95 DECLARE_PER_CPU(struct cpu, cpu_devices);
  96 #endif
  97
  98 /*
  99  * These states are not related to the core CPU hotplug mechanism. They are
 100  * used by various (sub)architectures to track internal state
 101  */
 102 #define CPU_ONLINE              0x0002 /* CPU is up */
 103 #define CPU_UP_PREPARE          0x0003 /* CPU coming up */
 104 #define CPU_DEAD                0x0007 /* CPU dead */
 105 #define CPU_DEAD_FROZEN         0x0008 /* CPU timed out on unplug */
 106 #define CPU_POST_DEAD           0x0009 /* CPU successfully unplugged */
 107 #define CPU_BROKEN              0x000B /* CPU did not die properly */
 108
 109 #ifdef CONFIG_SMP
 110 extern bool cpuhp_tasks_frozen;
 111 int add_cpu(unsigned int cpu);
 112 int cpu_device_up(struct device *dev);
 113 void notify_cpu_starting(unsigned int cpu);
 114 extern void cpu_maps_update_begin(void);
 115 extern void cpu_maps_update_done(void);
 116 int bringup_hibernate_cpu(unsigned int sleep_cpu);
 117 void bringup_nonboot_cpus(unsigned int max_cpus);
 118
 119 #else   /* CONFIG_SMP */
 120 #define cpuhp_tasks_frozen      0
 121
 122 static inline void cpu_maps_update_begin(void)
 123 {
 124 }
 125
 126 static inline void cpu_maps_update_done(void)
 127 {
 128 }
 129
 130 static inline int add_cpu(unsigned int cpu) { return 0;}
 131
 132 #endif /* CONFIG_SMP */
 133 extern const struct bus_type cpu_subsys;
 134
 135 #ifdef CONFIG_PM_SLEEP_SMP
 136 extern int freeze_secondary_cpus(int primary);
 137 extern void thaw_secondary_cpus(void);
 138
 139 static inline int suspend_disable_secondary_cpus(void)
 140 {
 141         int cpu = 0;
 142
 143         if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
 144                 cpu = -1;
 145
 146         return freeze_secondary_cpus(cpu);
 147 }
 148 static inline void suspend_enable_secondary_cpus(void)
 149 {
 150         return thaw_secondary_cpus();
 151 }
 152
 153 #else /* !CONFIG_PM_SLEEP_SMP */
 154 static inline void thaw_secondary_cpus(void) {}
 155 static inline int suspend_disable_secondary_cpus(void) { return 0; }
 156 static inline void suspend_enable_secondary_cpus(void) { }
 157 #endif /* !CONFIG_PM_SLEEP_SMP */
 158
 159 void __noreturn cpu_startup_entry(enum cpuhp_state state);
 160
 161 void cpu_idle_poll_ctrl(bool enable);
 162
 163 bool cpu_in_idle(unsigned long pc);
 164
 165 void arch_cpu_idle(void);
 166 void arch_cpu_idle_prepare(void);
 167 void arch_cpu_idle_enter(void);
 168 void arch_cpu_idle_exit(void);
 169 void arch_tick_broadcast_enter(void);
 170 void arch_tick_broadcast_exit(void);
 171 void __noreturn arch_cpu_idle_dead(void);
 172
 173 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
 174 void arch_cpu_finalize_init(void);
 175 #else
 176 static inline void arch_cpu_finalize_init(void) { }
 177 #endif
 178
 179 void play_idle_precise(u64 duration_ns, u64 latency_ns);
 180
 181 static inline void play_idle(unsigned long duration_us)
 182 {
 183         play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
 184 }
 185
 186 #ifdef CONFIG_HOTPLUG_CPU
 187 void cpuhp_report_idle_dead(void);
 188 #else
 189 static inline void cpuhp_report_idle_dead(void) { }
 190 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
 191
 192 #ifdef CONFIG_CPU_MITIGATIONS
 193 extern bool cpu_mitigations_off(void);
 194 extern bool cpu_mitigations_auto_nosmt(void);
 195 #else
 196 static inline bool cpu_mitigations_off(void)
 197 {
 198         return true;
 199 }
 200 static inline bool cpu_mitigations_auto_nosmt(void)
 201 {
 202         return false;
 203 }
 204 #endif
 205
 206 #endif /* _LINUX_CPU_H_ */