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 16 #ifdef CONFIG_GENERIC_CLOCKEVENTS 17 extern void __init tick_init(void); 18 /* Should be core only, but ARM BL switcher requires it */ 19 extern void tick_suspend_local(void); 20 /* Should be core only, but XEN resume magic and ARM BL switcher require it */ 21 extern void tick_resume_local(void); 22 extern void tick_cleanup_dead_cpu(int cpu); 23 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 24 static inline void tick_init(void) { } 25 static inline void tick_suspend_local(void) { } 26 static inline void tick_resume_local(void) { } 27 static inline void tick_cleanup_dead_cpu(int cpu) { } 28 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 29 30 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_HOTPLUG_CPU) 31 extern int tick_cpu_dying(unsigned int cpu); 32 #else 33 #define tick_cpu_dying NULL 34 #endif 35 36 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND) 37 extern void tick_freeze(void); 38 extern void tick_unfreeze(void); 39 #else 40 static inline void tick_freeze(void) { } 41 static inline void tick_unfreeze(void) { } 42 #endif 43 44 #ifdef CONFIG_TICK_ONESHOT 45 extern void tick_irq_enter(void); 46 # ifndef arch_needs_cpu 47 # define arch_needs_cpu() (0) 48 # endif 49 # else 50 static inline void tick_irq_enter(void) { } 51 #endif 52 53 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 54 extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu); 55 #else 56 static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { } 57 #endif 58 59 enum tick_broadcast_mode { 60 TICK_BROADCAST_OFF, 61 TICK_BROADCAST_ON, 62 TICK_BROADCAST_FORCE, 63 }; 64 65 enum tick_broadcast_state { 66 TICK_BROADCAST_EXIT, 67 TICK_BROADCAST_ENTER, 68 }; 69 70 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 71 extern void tick_broadcast_control(enum tick_broadcast_mode mode); 72 #else 73 static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { } 74 #endif /* BROADCAST */ 75 76 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU) 77 extern void tick_offline_cpu(unsigned int cpu); 78 #else 79 static inline void tick_offline_cpu(unsigned int cpu) { } 80 #endif 81 82 #ifdef CONFIG_GENERIC_CLOCKEVENTS 83 extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state); 84 #else 85 static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state) 86 { 87 return 0; 88 } 89 #endif 90 91 static inline void tick_broadcast_enable(void) 92 { 93 tick_broadcast_control(TICK_BROADCAST_ON); 94 } 95 static inline void tick_broadcast_disable(void) 96 { 97 tick_broadcast_control(TICK_BROADCAST_OFF); 98 } 99 static inline void tick_broadcast_force(void) 100 { 101 tick_broadcast_control(TICK_BROADCAST_FORCE); 102 } 103 static inline int tick_broadcast_enter(void) 104 { 105 return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER); 106 } 107 static inline void tick_broadcast_exit(void) 108 { 109 tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT); 110 } 111 112 enum tick_dep_bits { 113 TICK_DEP_BIT_POSIX_TIMER = 0, 114 TICK_DEP_BIT_PERF_EVENTS = 1, 115 TICK_DEP_BIT_SCHED = 2, 116 TICK_DEP_BIT_CLOCK_UNSTABLE = 3, 117 TICK_DEP_BIT_RCU = 4, 118 TICK_DEP_BIT_RCU_EXP = 5 119 }; 120 #define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP 121 122 #define TICK_DEP_MASK_NONE 0 123 #define TICK_DEP_MASK_POSIX_TIMER (1 << TICK_DEP_BIT_POSIX_TIMER) 124 #define TICK_DEP_MASK_PERF_EVENTS (1 << TICK_DEP_BIT_PERF_EVENTS) 125 #define TICK_DEP_MASK_SCHED (1 << TICK_DEP_BIT_SCHED) 126 #define TICK_DEP_MASK_CLOCK_UNSTABLE (1 << TICK_DEP_BIT_CLOCK_UNSTABLE) 127 #define TICK_DEP_MASK_RCU (1 << TICK_DEP_BIT_RCU) 128 #define TICK_DEP_MASK_RCU_EXP (1 << TICK_DEP_BIT_RCU_EXP) 129 130 #ifdef CONFIG_NO_HZ_COMMON 131 extern bool tick_nohz_enabled; 132 extern bool tick_nohz_tick_stopped(void); 133 extern bool tick_nohz_tick_stopped_cpu(int cpu); 134 extern void tick_nohz_idle_stop_tick(void); 135 extern void tick_nohz_idle_retain_tick(void); 136 extern void tick_nohz_idle_restart_tick(void); 137 extern void tick_nohz_idle_enter(void); 138 extern void tick_nohz_idle_exit(void); 139 extern void tick_nohz_irq_exit(void); 140 extern bool tick_nohz_idle_got_tick(void); 141 extern ktime_t tick_nohz_get_next_hrtimer(void); 142 extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next); 143 extern unsigned long tick_nohz_get_idle_calls(void); 144 extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu); 145 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 146 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); 147 #else /* !CONFIG_NO_HZ_COMMON */ 148 #define tick_nohz_enabled (0) 149 static inline int tick_nohz_tick_stopped(void) { return 0; } 150 static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; } 151 static inline void tick_nohz_idle_stop_tick(void) { } 152 static inline void tick_nohz_idle_retain_tick(void) { } 153 static inline void tick_nohz_idle_restart_tick(void) { } 154 static inline void tick_nohz_idle_enter(void) { } 155 static inline void tick_nohz_idle_exit(void) { } 156 static inline bool tick_nohz_idle_got_tick(void) { return false; } 157 static inline ktime_t tick_nohz_get_next_hrtimer(void) 158 { 159 /* Next wake up is the tick period, assume it starts now */ 160 return ktime_add(ktime_get(), TICK_NSEC); 161 } 162 static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next) 163 { 164 *delta_next = TICK_NSEC; 165 return *delta_next; 166 } 167 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 168 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } 169 #endif /* !CONFIG_NO_HZ_COMMON */ 170 171 #ifdef CONFIG_NO_HZ_FULL 172 extern bool tick_nohz_full_running; 173 extern cpumask_var_t tick_nohz_full_mask; 174 175 static inline bool tick_nohz_full_enabled(void) 176 { 177 if (!context_tracking_enabled()) 178 return false; 179 180 return tick_nohz_full_running; 181 } 182 183 /* 184 * Check if a CPU is part of the nohz_full subset. Arrange for evaluating 185 * the cpu expression (typically smp_processor_id()) _after_ the static 186 * key. 187 */ 188 #define tick_nohz_full_cpu(_cpu) ({ \ 189 bool __ret = false; \ 190 if (tick_nohz_full_enabled()) \ 191 __ret = cpumask_test_cpu((_cpu), tick_nohz_full_mask); \ 192 __ret; \ 193 }) 194 195 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) 196 { 197 if (tick_nohz_full_enabled()) 198 cpumask_or(mask, mask, tick_nohz_full_mask); 199 } 200 201 extern void tick_nohz_dep_set(enum tick_dep_bits bit); 202 extern void tick_nohz_dep_clear(enum tick_dep_bits bit); 203 extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit); 204 extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit); 205 extern void tick_nohz_dep_set_task(struct task_struct *tsk, 206 enum tick_dep_bits bit); 207 extern void tick_nohz_dep_clear_task(struct task_struct *tsk, 208 enum tick_dep_bits bit); 209 extern void tick_nohz_dep_set_signal(struct task_struct *tsk, 210 enum tick_dep_bits bit); 211 extern void tick_nohz_dep_clear_signal(struct signal_struct *signal, 212 enum tick_dep_bits bit); 213 extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu); 214 215 /* 216 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases 217 * on top of static keys. 218 */ 219 static inline void tick_dep_set(enum tick_dep_bits bit) 220 { 221 if (tick_nohz_full_enabled()) 222 tick_nohz_dep_set(bit); 223 } 224 225 static inline void tick_dep_clear(enum tick_dep_bits bit) 226 { 227 if (tick_nohz_full_enabled()) 228 tick_nohz_dep_clear(bit); 229 } 230 231 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) 232 { 233 if (tick_nohz_full_cpu(cpu)) 234 tick_nohz_dep_set_cpu(cpu, bit); 235 } 236 237 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) 238 { 239 if (tick_nohz_full_cpu(cpu)) 240 tick_nohz_dep_clear_cpu(cpu, bit); 241 } 242 243 static inline void tick_dep_set_task(struct task_struct *tsk, 244 enum tick_dep_bits bit) 245 { 246 if (tick_nohz_full_enabled()) 247 tick_nohz_dep_set_task(tsk, bit); 248 } 249 static inline void tick_dep_clear_task(struct task_struct *tsk, 250 enum tick_dep_bits bit) 251 { 252 if (tick_nohz_full_enabled()) 253 tick_nohz_dep_clear_task(tsk, bit); 254 } 255 static inline void tick_dep_set_signal(struct task_struct *tsk, 256 enum tick_dep_bits bit) 257 { 258 if (tick_nohz_full_enabled()) 259 tick_nohz_dep_set_signal(tsk, bit); 260 } 261 static inline void tick_dep_clear_signal(struct signal_struct *signal, 262 enum tick_dep_bits bit) 263 { 264 if (tick_nohz_full_enabled()) 265 tick_nohz_dep_clear_signal(signal, bit); 266 } 267 268 extern void tick_nohz_full_kick_cpu(int cpu); 269 extern void __tick_nohz_task_switch(void); 270 extern void __init tick_nohz_full_setup(cpumask_var_t cpumask); 271 #else 272 static inline bool tick_nohz_full_enabled(void) { return false; } 273 static inline bool tick_nohz_full_cpu(int cpu) { return false; } 274 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { } 275 276 static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 277 static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 278 static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; } 279 280 static inline void tick_dep_set(enum tick_dep_bits bit) { } 281 static inline void tick_dep_clear(enum tick_dep_bits bit) { } 282 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 283 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 284 static inline void tick_dep_set_task(struct task_struct *tsk, 285 enum tick_dep_bits bit) { } 286 static inline void tick_dep_clear_task(struct task_struct *tsk, 287 enum tick_dep_bits bit) { } 288 static inline void tick_dep_set_signal(struct task_struct *tsk, 289 enum tick_dep_bits bit) { } 290 static inline void tick_dep_clear_signal(struct signal_struct *signal, 291 enum tick_dep_bits bit) { } 292 293 static inline void tick_nohz_full_kick_cpu(int cpu) { } 294 static inline void __tick_nohz_task_switch(void) { } 295 static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { } 296 #endif 297 298 static inline void tick_nohz_task_switch(void) 299 { 300 if (tick_nohz_full_enabled()) 301 __tick_nohz_task_switch(); 302 } 303 304 static inline void tick_nohz_user_enter_prepare(void) 305 { 306 if (tick_nohz_full_cpu(smp_processor_id())) 307 rcu_nocb_flush_deferred_wakeup(); 308 } 309 310 #endif 311