1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Tick related global functions 4 */ 5 #ifndef _LINUX_TICK_H 6 #define _LINUX_TICK_H 7 8 #include <linux/clockchips.h> 9 #include <linux/irqflags.h> 10 #include <linux/percpu.h> 11 #include <linux/context_tracking_state.h> 12 #include <linux/cpumask.h> 13 #include <linux/sched.h> 14 #include <linux/rcupdate.h> 15 #include <linux/static_key.h> 16 17 #ifdef CONFIG_GENERIC_CLOCKEVENTS 18 extern void __init tick_init(void); 19 /* Should be core only, but ARM BL switcher requires it */ 20 extern void tick_suspend_local(void); 21 /* Should be core only, but XEN resume magic and ARM BL switcher require it */ 22 extern void tick_resume_local(void); 23 extern void tick_handover_do_timer(void); 24 extern void tick_cleanup_dead_cpu(int cpu); 25 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 26 static inline void tick_init(void) { } 27 static inline void tick_suspend_local(void) { } 28 static inline void tick_resume_local(void) { } 29 static inline void tick_handover_do_timer(void) { } 30 static inline void tick_cleanup_dead_cpu(int cpu) { } 31 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 32 33 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND) 34 extern void tick_freeze(void); 35 extern void tick_unfreeze(void); 36 #else 37 static inline void tick_freeze(void) { } 38 static inline void tick_unfreeze(void) { } 39 #endif 40 41 #ifdef CONFIG_TICK_ONESHOT 42 extern void tick_irq_enter(void); 43 # ifndef arch_needs_cpu 44 # define arch_needs_cpu() (0) 45 # endif 46 # else 47 static inline void tick_irq_enter(void) { } 48 #endif 49 50 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 51 extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu); 52 #else 53 static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { } 54 #endif 55 56 enum tick_broadcast_mode { 57 TICK_BROADCAST_OFF, 58 TICK_BROADCAST_ON, 59 TICK_BROADCAST_FORCE, 60 }; 61 62 enum tick_broadcast_state { 63 TICK_BROADCAST_EXIT, 64 TICK_BROADCAST_ENTER, 65 }; 66 67 extern struct static_key_false arch_needs_tick_broadcast; 68 69 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 70 extern void tick_broadcast_control(enum tick_broadcast_mode mode); 71 #else 72 static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { } 73 #endif /* BROADCAST */ 74 75 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU) 76 extern void tick_offline_cpu(unsigned int cpu); 77 #else 78 static inline void tick_offline_cpu(unsigned int cpu) { } 79 #endif 80 81 #ifdef CONFIG_GENERIC_CLOCKEVENTS 82 extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state); 83 #else 84 static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state) 85 { 86 return 0; 87 } 88 #endif 89 90 static inline void tick_broadcast_enable(void) 91 { 92 tick_broadcast_control(TICK_BROADCAST_ON); 93 } 94 static inline void tick_broadcast_disable(void) 95 { 96 tick_broadcast_control(TICK_BROADCAST_OFF); 97 } 98 static inline void tick_broadcast_force(void) 99 { 100 tick_broadcast_control(TICK_BROADCAST_FORCE); 101 } 102 static inline int tick_broadcast_enter(void) 103 { 104 return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER); 105 } 106 static inline void tick_broadcast_exit(void) 107 { 108 tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT); 109 } 110 111 enum tick_dep_bits { 112 TICK_DEP_BIT_POSIX_TIMER = 0, 113 TICK_DEP_BIT_PERF_EVENTS = 1, 114 TICK_DEP_BIT_SCHED = 2, 115 TICK_DEP_BIT_CLOCK_UNSTABLE = 3, 116 TICK_DEP_BIT_RCU = 4, 117 TICK_DEP_BIT_RCU_EXP = 5 118 }; 119 #define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP 120 121 #define TICK_DEP_MASK_NONE 0 122 #define TICK_DEP_MASK_POSIX_TIMER (1 << TICK_DEP_BIT_POSIX_TIMER) 123 #define TICK_DEP_MASK_PERF_EVENTS (1 << TICK_DEP_BIT_PERF_EVENTS) 124 #define TICK_DEP_MASK_SCHED (1 << TICK_DEP_BIT_SCHED) 125 #define TICK_DEP_MASK_CLOCK_UNSTABLE (1 << TICK_DEP_BIT_CLOCK_UNSTABLE) 126 #define TICK_DEP_MASK_RCU (1 << TICK_DEP_BIT_RCU) 127 #define TICK_DEP_MASK_RCU_EXP (1 << TICK_DEP_BIT_RCU_EXP) 128 129 #ifdef CONFIG_NO_HZ_COMMON 130 extern bool tick_nohz_enabled; 131 extern bool tick_nohz_tick_stopped(void); 132 extern bool tick_nohz_tick_stopped_cpu(int cpu); 133 extern void tick_nohz_idle_stop_tick(void); 134 extern void tick_nohz_idle_retain_tick(void); 135 extern void tick_nohz_idle_restart_tick(void); 136 extern void tick_nohz_idle_enter(void); 137 extern void tick_nohz_idle_exit(void); 138 extern void tick_nohz_irq_exit(void); 139 extern bool tick_nohz_idle_got_tick(void); 140 extern ktime_t tick_nohz_get_next_hrtimer(void); 141 extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next); 142 extern unsigned long tick_nohz_get_idle_calls(void); 143 extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu); 144 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 145 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); 146 #else /* !CONFIG_NO_HZ_COMMON */ 147 #define tick_nohz_enabled (0) 148 static inline int tick_nohz_tick_stopped(void) { return 0; } 149 static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; } 150 static inline void tick_nohz_idle_stop_tick(void) { } 151 static inline void tick_nohz_idle_retain_tick(void) { } 152 static inline void tick_nohz_idle_restart_tick(void) { } 153 static inline void tick_nohz_idle_enter(void) { } 154 static inline void tick_nohz_idle_exit(void) { } 155 static inline bool tick_nohz_idle_got_tick(void) { return false; } 156 static inline ktime_t tick_nohz_get_next_hrtimer(void) 157 { 158 /* Next wake up is the tick period, assume it starts now */ 159 return ktime_add(ktime_get(), TICK_NSEC); 160 } 161 static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next) 162 { 163 *delta_next = TICK_NSEC; 164 return *delta_next; 165 } 166 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 167 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } 168 #endif /* !CONFIG_NO_HZ_COMMON */ 169 170 #ifdef CONFIG_NO_HZ_FULL 171 extern bool tick_nohz_full_running; 172 extern cpumask_var_t tick_nohz_full_mask; 173 174 static inline bool tick_nohz_full_enabled(void) 175 { 176 if (!context_tracking_enabled()) 177 return false; 178 179 return tick_nohz_full_running; 180 } 181 182 /* 183 * Check if a CPU is part of the nohz_full subset. Arrange for evaluating 184 * the cpu expression (typically smp_processor_id()) _after_ the static 185 * key. 186 */ 187 #define tick_nohz_full_cpu(_cpu) ({ \ 188 bool __ret = false; \ 189 if (tick_nohz_full_enabled()) \ 190 __ret = cpumask_test_cpu((_cpu), tick_nohz_full_mask); \ 191 __ret; \ 192 }) 193 194 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) 195 { 196 if (tick_nohz_full_enabled()) 197 cpumask_or(mask, mask, tick_nohz_full_mask); 198 } 199 200 extern void tick_nohz_dep_set(enum tick_dep_bits bit); 201 extern void tick_nohz_dep_clear(enum tick_dep_bits bit); 202 extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit); 203 extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit); 204 extern void tick_nohz_dep_set_task(struct task_struct *tsk, 205 enum tick_dep_bits bit); 206 extern void tick_nohz_dep_clear_task(struct task_struct *tsk, 207 enum tick_dep_bits bit); 208 extern void tick_nohz_dep_set_signal(struct task_struct *tsk, 209 enum tick_dep_bits bit); 210 extern void tick_nohz_dep_clear_signal(struct signal_struct *signal, 211 enum tick_dep_bits bit); 212 extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu); 213 214 /* 215 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases 216 * on top of static keys. 217 */ 218 static inline void tick_dep_set(enum tick_dep_bits bit) 219 { 220 if (tick_nohz_full_enabled()) 221 tick_nohz_dep_set(bit); 222 } 223 224 static inline void tick_dep_clear(enum tick_dep_bits bit) 225 { 226 if (tick_nohz_full_enabled()) 227 tick_nohz_dep_clear(bit); 228 } 229 230 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) 231 { 232 if (tick_nohz_full_cpu(cpu)) 233 tick_nohz_dep_set_cpu(cpu, bit); 234 } 235 236 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) 237 { 238 if (tick_nohz_full_cpu(cpu)) 239 tick_nohz_dep_clear_cpu(cpu, bit); 240 } 241 242 static inline void tick_dep_set_task(struct task_struct *tsk, 243 enum tick_dep_bits bit) 244 { 245 if (tick_nohz_full_enabled()) 246 tick_nohz_dep_set_task(tsk, bit); 247 } 248 static inline void tick_dep_clear_task(struct task_struct *tsk, 249 enum tick_dep_bits bit) 250 { 251 if (tick_nohz_full_enabled()) 252 tick_nohz_dep_clear_task(tsk, bit); 253 } 254 static inline void tick_dep_set_signal(struct task_struct *tsk, 255 enum tick_dep_bits bit) 256 { 257 if (tick_nohz_full_enabled()) 258 tick_nohz_dep_set_signal(tsk, bit); 259 } 260 static inline void tick_dep_clear_signal(struct signal_struct *signal, 261 enum tick_dep_bits bit) 262 { 263 if (tick_nohz_full_enabled()) 264 tick_nohz_dep_clear_signal(signal, bit); 265 } 266 267 extern void tick_nohz_full_kick_cpu(int cpu); 268 extern void __tick_nohz_task_switch(void); 269 extern void __init tick_nohz_full_setup(cpumask_var_t cpumask); 270 #else 271 static inline bool tick_nohz_full_enabled(void) { return false; } 272 static inline bool tick_nohz_full_cpu(int cpu) { return false; } 273 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { } 274 275 static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 276 static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 277 static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; } 278 279 static inline void tick_dep_set(enum tick_dep_bits bit) { } 280 static inline void tick_dep_clear(enum tick_dep_bits bit) { } 281 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 282 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 283 static inline void tick_dep_set_task(struct task_struct *tsk, 284 enum tick_dep_bits bit) { } 285 static inline void tick_dep_clear_task(struct task_struct *tsk, 286 enum tick_dep_bits bit) { } 287 static inline void tick_dep_set_signal(struct task_struct *tsk, 288 enum tick_dep_bits bit) { } 289 static inline void tick_dep_clear_signal(struct signal_struct *signal, 290 enum tick_dep_bits bit) { } 291 292 static inline void tick_nohz_full_kick_cpu(int cpu) { } 293 static inline void __tick_nohz_task_switch(void) { } 294 static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { } 295 #endif 296 297 static inline void tick_nohz_task_switch(void) 298 { 299 if (tick_nohz_full_enabled()) 300 __tick_nohz_task_switch(); 301 } 302 303 static inline void tick_nohz_user_enter_prepare(void) 304 { 305 if (tick_nohz_full_cpu(smp_processor_id())) 306 rcu_nocb_flush_deferred_wakeup(); 307 } 308 309 #endif 310