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 61 extern __printf(4, 5) 62 struct device *cpu_device_create(struct device *parent, void *drvdata, 63 const struct attribute_group **groups, 64 const char *fmt, ...); 65 #ifdef CONFIG_HOTPLUG_CPU 66 extern void unregister_cpu(struct cpu *cpu); 67 extern ssize_t arch_cpu_probe(const char *, size_t); 68 extern ssize_t arch_cpu_release(const char *, size_t); 69 #endif 70 71 /* 72 * These states are not related to the core CPU hotplug mechanism. They are 73 * used by various (sub)architectures to track internal state 74 */ 75 #define CPU_ONLINE 0x0002 /* CPU is up */ 76 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */ 77 #define CPU_DEAD 0x0007 /* CPU dead */ 78 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */ 79 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */ 80 #define CPU_BROKEN 0x000B /* CPU did not die properly */ 81 82 #ifdef CONFIG_SMP 83 extern bool cpuhp_tasks_frozen; 84 int cpu_up(unsigned int cpu); 85 void notify_cpu_starting(unsigned int cpu); 86 extern void cpu_maps_update_begin(void); 87 extern void cpu_maps_update_done(void); 88 89 #else /* CONFIG_SMP */ 90 #define cpuhp_tasks_frozen 0 91 92 static inline void cpu_maps_update_begin(void) 93 { 94 } 95 96 static inline void cpu_maps_update_done(void) 97 { 98 } 99 100 #endif /* CONFIG_SMP */ 101 extern struct bus_type cpu_subsys; 102 103 #ifdef CONFIG_HOTPLUG_CPU 104 extern void cpus_write_lock(void); 105 extern void cpus_write_unlock(void); 106 extern void cpus_read_lock(void); 107 extern void cpus_read_unlock(void); 108 extern int cpus_read_trylock(void); 109 extern void lockdep_assert_cpus_held(void); 110 extern void cpu_hotplug_disable(void); 111 extern void cpu_hotplug_enable(void); 112 void clear_tasks_mm_cpumask(int cpu); 113 int cpu_down(unsigned int cpu); 114 115 #else /* CONFIG_HOTPLUG_CPU */ 116 117 static inline void cpus_write_lock(void) { } 118 static inline void cpus_write_unlock(void) { } 119 static inline void cpus_read_lock(void) { } 120 static inline void cpus_read_unlock(void) { } 121 static inline int cpus_read_trylock(void) { return true; } 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); 140 141 static inline int suspend_disable_secondary_cpus(void) 142 { 143 int cpu = 0; 144 145 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) 146 cpu = -1; 147 148 return freeze_secondary_cpus(cpu); 149 } 150 static inline void suspend_enable_secondary_cpus(void) 151 { 152 return enable_nonboot_cpus(); 153 } 154 155 #else /* !CONFIG_PM_SLEEP_SMP */ 156 static inline int disable_nonboot_cpus(void) { return 0; } 157 static inline void enable_nonboot_cpus(void) {} 158 static inline int suspend_disable_secondary_cpus(void) { return 0; } 159 static inline void suspend_enable_secondary_cpus(void) { } 160 #endif /* !CONFIG_PM_SLEEP_SMP */ 161 162 void cpu_startup_entry(enum cpuhp_state state); 163 164 void cpu_idle_poll_ctrl(bool enable); 165 166 /* Attach to any functions which should be considered cpuidle. */ 167 #define __cpuidle __attribute__((__section__(".cpuidle.text"))) 168 169 bool cpu_in_idle(unsigned long pc); 170 171 void arch_cpu_idle(void); 172 void arch_cpu_idle_prepare(void); 173 void arch_cpu_idle_enter(void); 174 void arch_cpu_idle_exit(void); 175 void arch_cpu_idle_dead(void); 176 177 int cpu_report_state(int cpu); 178 int cpu_check_up_prepare(int cpu); 179 void cpu_set_state_online(int cpu); 180 void play_idle(unsigned long duration_ms); 181 182 #ifdef CONFIG_HOTPLUG_CPU 183 bool cpu_wait_death(unsigned int cpu, int seconds); 184 bool cpu_report_death(void); 185 void cpuhp_report_idle_dead(void); 186 #else 187 static inline void cpuhp_report_idle_dead(void) { } 188 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ 189 190 enum cpuhp_smt_control { 191 CPU_SMT_ENABLED, 192 CPU_SMT_DISABLED, 193 CPU_SMT_FORCE_DISABLED, 194 CPU_SMT_NOT_SUPPORTED, 195 CPU_SMT_NOT_IMPLEMENTED, 196 }; 197 198 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT) 199 extern enum cpuhp_smt_control cpu_smt_control; 200 extern void cpu_smt_disable(bool force); 201 extern void cpu_smt_check_topology(void); 202 #else 203 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED) 204 static inline void cpu_smt_disable(bool force) { } 205 static inline void cpu_smt_check_topology(void) { } 206 #endif 207 208 /* 209 * These are used for a global "mitigations=" cmdline option for toggling 210 * optional CPU mitigations. 211 */ 212 enum cpu_mitigations { 213 CPU_MITIGATIONS_OFF, 214 CPU_MITIGATIONS_AUTO, 215 CPU_MITIGATIONS_AUTO_NOSMT, 216 }; 217 218 extern enum cpu_mitigations cpu_mitigations; 219 220 /* mitigations=off */ 221 static inline bool cpu_mitigations_off(void) 222 { 223 return cpu_mitigations == CPU_MITIGATIONS_OFF; 224 } 225 226 /* mitigations=auto,nosmt */ 227 static inline bool cpu_mitigations_auto_nosmt(void) 228 { 229 return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT; 230 } 231 232 #endif /* _LINUX_CPU_H_ */ 233