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 extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
  63                                         struct device_attribute *attr,
  64                                         char *buf);
  65 extern ssize_t cpu_show_itlb_multihit(struct device *dev,
  66                                       struct device_attribute *attr, char *buf);
  67
  68 extern __printf(4, 5)
  69 struct device *cpu_device_create(struct device *parent, void *drvdata,
  70                                  const struct attribute_group **groups,
  71                                  const char *fmt, ...);
  72 #ifdef CONFIG_HOTPLUG_CPU
  73 extern void unregister_cpu(struct cpu *cpu);
  74 extern ssize_t arch_cpu_probe(const char *, size_t);
  75 extern ssize_t arch_cpu_release(const char *, size_t);
  76 #endif
  77
  78 /*
  79  * These states are not related to the core CPU hotplug mechanism. They are
  80  * used by various (sub)architectures to track internal state
  81  */
  82 #define CPU_ONLINE              0x0002 /* CPU is up */
  83 #define CPU_UP_PREPARE          0x0003 /* CPU coming up */
  84 #define CPU_DEAD                0x0007 /* CPU dead */
  85 #define CPU_DEAD_FROZEN         0x0008 /* CPU timed out on unplug */
  86 #define CPU_POST_DEAD           0x0009 /* CPU successfully unplugged */
  87 #define CPU_BROKEN              0x000B /* CPU did not die properly */
  88
  89 #ifdef CONFIG_SMP
  90 extern bool cpuhp_tasks_frozen;
  91 int cpu_up(unsigned int cpu);
  92 void notify_cpu_starting(unsigned int cpu);
  93 extern void cpu_maps_update_begin(void);
  94 extern void cpu_maps_update_done(void);
  95
  96 #else   /* CONFIG_SMP */
  97 #define cpuhp_tasks_frozen      0
  98
  99 static inline void cpu_maps_update_begin(void)
 100 {
 101 }
 102
 103 static inline void cpu_maps_update_done(void)
 104 {
 105 }
 106
 107 #endif /* CONFIG_SMP */
 108 extern struct bus_type cpu_subsys;
 109
 110 #ifdef CONFIG_HOTPLUG_CPU
 111 extern void cpus_write_lock(void);
 112 extern void cpus_write_unlock(void);
 113 extern void cpus_read_lock(void);
 114 extern void cpus_read_unlock(void);
 115 extern int  cpus_read_trylock(void);
 116 extern void lockdep_assert_cpus_held(void);
 117 extern void cpu_hotplug_disable(void);
 118 extern void cpu_hotplug_enable(void);
 119 void clear_tasks_mm_cpumask(int cpu);
 120 int cpu_down(unsigned int cpu);
 121
 122 #else /* CONFIG_HOTPLUG_CPU */
 123
 124 static inline void cpus_write_lock(void) { }
 125 static inline void cpus_write_unlock(void) { }
 126 static inline void cpus_read_lock(void) { }
 127 static inline void cpus_read_unlock(void) { }
 128 static inline int  cpus_read_trylock(void) { return true; }
 129 static inline void lockdep_assert_cpus_held(void) { }
 130 static inline void cpu_hotplug_disable(void) { }
 131 static inline void cpu_hotplug_enable(void) { }
 132 #endif  /* !CONFIG_HOTPLUG_CPU */
 133
 134 /* Wrappers which go away once all code is converted */
 135 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
 136 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
 137 static inline void get_online_cpus(void) { cpus_read_lock(); }
 138 static inline void put_online_cpus(void) { cpus_read_unlock(); }
 139
 140 #ifdef CONFIG_PM_SLEEP_SMP
 141 extern int freeze_secondary_cpus(int primary);
 142 static inline int disable_nonboot_cpus(void)
 143 {
 144         return freeze_secondary_cpus(0);
 145 }
 146 extern void enable_nonboot_cpus(void);
 147
 148 static inline int suspend_disable_secondary_cpus(void)
 149 {
 150         int cpu = 0;
 151
 152         if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
 153                 cpu = -1;
 154
 155         return freeze_secondary_cpus(cpu);
 156 }
 157 static inline void suspend_enable_secondary_cpus(void)
 158 {
 159         return enable_nonboot_cpus();
 160 }
 161
 162 #else /* !CONFIG_PM_SLEEP_SMP */
 163 static inline int disable_nonboot_cpus(void) { return 0; }
 164 static inline void enable_nonboot_cpus(void) {}
 165 static inline int suspend_disable_secondary_cpus(void) { return 0; }
 166 static inline void suspend_enable_secondary_cpus(void) { }
 167 #endif /* !CONFIG_PM_SLEEP_SMP */
 168
 169 void cpu_startup_entry(enum cpuhp_state state);
 170
 171 void cpu_idle_poll_ctrl(bool enable);
 172
 173 /* Attach to any functions which should be considered cpuidle. */
 174 #define __cpuidle       __attribute__((__section__(".cpuidle.text")))
 175
 176 bool cpu_in_idle(unsigned long pc);
 177
 178 void arch_cpu_idle(void);
 179 void arch_cpu_idle_prepare(void);
 180 void arch_cpu_idle_enter(void);
 181 void arch_cpu_idle_exit(void);
 182 void arch_cpu_idle_dead(void);
 183
 184 int cpu_report_state(int cpu);
 185 int cpu_check_up_prepare(int cpu);
 186 void cpu_set_state_online(int cpu);
 187 void play_idle_precise(u64 duration_ns, u64 latency_ns);
 188
 189 static inline void play_idle(unsigned long duration_us)
 190 {
 191         play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
 192 }
 193
 194 #ifdef CONFIG_HOTPLUG_CPU
 195 bool cpu_wait_death(unsigned int cpu, int seconds);
 196 bool cpu_report_death(void);
 197 void cpuhp_report_idle_dead(void);
 198 #else
 199 static inline void cpuhp_report_idle_dead(void) { }
 200 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
 201
 202 enum cpuhp_smt_control {
 203         CPU_SMT_ENABLED,
 204         CPU_SMT_DISABLED,
 205         CPU_SMT_FORCE_DISABLED,
 206         CPU_SMT_NOT_SUPPORTED,
 207         CPU_SMT_NOT_IMPLEMENTED,
 208 };
 209
 210 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
 211 extern enum cpuhp_smt_control cpu_smt_control;
 212 extern void cpu_smt_disable(bool force);
 213 extern void cpu_smt_check_topology(void);
 214 extern bool cpu_smt_possible(void);
 215 extern int cpuhp_smt_enable(void);
 216 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
 217 #else
 218 # define cpu_smt_control                (CPU_SMT_NOT_IMPLEMENTED)
 219 static inline void cpu_smt_disable(bool force) { }
 220 static inline void cpu_smt_check_topology(void) { }
 221 static inline bool cpu_smt_possible(void) { return false; }
 222 static inline int cpuhp_smt_enable(void) { return 0; }
 223 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
 224 #endif
 225
 226 extern bool cpu_mitigations_off(void);
 227 extern bool cpu_mitigations_auto_nosmt(void);
 228
 229 #endif /* _LINUX_CPU_H_ */