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_ */ 230