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 int cpus_read_trylock(void); 111 extern void lockdep_assert_cpus_held(void); 112 extern void cpu_hotplug_disable(void); 113 extern void cpu_hotplug_enable(void); 114 void clear_tasks_mm_cpumask(int cpu); 115 int cpu_down(unsigned int cpu); 116 117 #else /* CONFIG_HOTPLUG_CPU */ 118 119 static inline void cpus_write_lock(void) { } 120 static inline void cpus_write_unlock(void) { } 121 static inline void cpus_read_lock(void) { } 122 static inline void cpus_read_unlock(void) { } 123 static inline int cpus_read_trylock(void) { return true; } 124 static inline void lockdep_assert_cpus_held(void) { } 125 static inline void cpu_hotplug_disable(void) { } 126 static inline void cpu_hotplug_enable(void) { } 127 #endif /* !CONFIG_HOTPLUG_CPU */ 128 129 /* Wrappers which go away once all code is converted */ 130 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); } 131 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); } 132 static inline void get_online_cpus(void) { cpus_read_lock(); } 133 static inline void put_online_cpus(void) { cpus_read_unlock(); } 134 135 #ifdef CONFIG_PM_SLEEP_SMP 136 extern int freeze_secondary_cpus(int primary); 137 static inline int disable_nonboot_cpus(void) 138 { 139 return freeze_secondary_cpus(0); 140 } 141 extern void enable_nonboot_cpus(void); 142 143 static 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 } 152 static inline void suspend_enable_secondary_cpus(void) 153 { 154 return enable_nonboot_cpus(); 155 } 156 157 #else /* !CONFIG_PM_SLEEP_SMP */ 158 static inline int disable_nonboot_cpus(void) { return 0; } 159 static inline void enable_nonboot_cpus(void) {} 160 static inline int suspend_disable_secondary_cpus(void) { return 0; } 161 static inline void suspend_enable_secondary_cpus(void) { } 162 #endif /* !CONFIG_PM_SLEEP_SMP */ 163 164 void cpu_startup_entry(enum cpuhp_state state); 165 166 void cpu_idle_poll_ctrl(bool enable); 167 168 /* Attach to any functions which should be considered cpuidle. */ 169 #define __cpuidle __attribute__((__section__(".cpuidle.text"))) 170 171 bool cpu_in_idle(unsigned long pc); 172 173 void arch_cpu_idle(void); 174 void arch_cpu_idle_prepare(void); 175 void arch_cpu_idle_enter(void); 176 void arch_cpu_idle_exit(void); 177 void arch_cpu_idle_dead(void); 178 179 int cpu_report_state(int cpu); 180 int cpu_check_up_prepare(int cpu); 181 void cpu_set_state_online(int cpu); 182 void play_idle(unsigned long duration_ms); 183 184 #ifdef CONFIG_HOTPLUG_CPU 185 bool cpu_wait_death(unsigned int cpu, int seconds); 186 bool cpu_report_death(void); 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 enum 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) 201 extern enum cpuhp_smt_control cpu_smt_control; 202 extern void cpu_smt_disable(bool force); 203 extern void cpu_smt_check_topology(void); 204 #else 205 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) 206 static inline void cpu_smt_disable(bool force) { } 207 static inline void cpu_smt_check_topology(void) { } 208 #endif 209 210 /* 211 * These are used for a global "mitigations=" cmdline option for toggling 212 * optional CPU mitigations. 213 */ 214 enum cpu_mitigations { 215 CPU_MITIGATIONS_OFF, 216 CPU_MITIGATIONS_AUTO, 217 CPU_MITIGATIONS_AUTO_NOSMT, 218 }; 219 220 extern enum cpu_mitigations cpu_mitigations; 221 222 /* mitigations=off */ 223 static inline bool cpu_mitigations_off(void) 224 { 225 return cpu_mitigations == CPU_MITIGATIONS_OFF; 226 } 227 228 /* mitigations=auto,nosmt */ 229 static inline bool cpu_mitigations_auto_nosmt(void) 230 { 231 return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT; 232 } 233 234 #endif /* _LINUX_CPU_H_ */ 235