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 extern void tick_assert_timekeeping_handover(void); 33 #else 34 #define tick_cpu_dying NULL 35 static inline void tick_assert_timekeeping_handover(void) { } 36 #endif 37 38 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND) 39 extern void tick_freeze(void); 40 extern void tick_unfreeze(void); 41 #else 42 static inline void tick_freeze(void) { } 43 static inline void tick_unfreeze(void) { } 44 #endif 45 46 #ifdef CONFIG_TICK_ONESHOT 47 extern void tick_irq_enter(void); 48 # ifndef arch_needs_cpu 49 # define arch_needs_cpu() (0) 50 # endif 51 # else 52 static inline void tick_irq_enter(void) { } 53 #endif 54 55 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 56 extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu); 57 #else 58 static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { } 59 #endif 60 61 enum tick_broadcast_mode { 62 TICK_BROADCAST_OFF, 63 TICK_BROADCAST_ON, 64 TICK_BROADCAST_FORCE, 65 }; 66 67 enum tick_broadcast_state { 68 TICK_BROADCAST_EXIT, 69 TICK_BROADCAST_ENTER, 70 }; 71 72 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 73 extern void tick_broadcast_control(enum tick_broadcast_mode mode); 74 #else 75 static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { } 76 #endif /* BROADCAST */ 77 78 #ifdef CONFIG_GENERIC_CLOCKEVENTS 79 extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state); 80 #else 81 static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state) 82 { 83 return 0; 84 } 85 #endif 86 87 static inline void tick_broadcast_enable(void) 88 { 89 tick_broadcast_control(TICK_BROADCAST_ON); 90 } 91 static inline void tick_broadcast_disable(void) 92 { 93 tick_broadcast_control(TICK_BROADCAST_OFF); 94 } 95 static inline void tick_broadcast_force(void) 96 { 97 tick_broadcast_control(TICK_BROADCAST_FORCE); 98 } 99 static inline int tick_broadcast_enter(void) 100 { 101 return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER); 102 } 103 static inline void tick_broadcast_exit(void) 104 { 105 tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT); 106 } 107 108 enum tick_dep_bits { 109 TICK_DEP_BIT_POSIX_TIMER = 0, 110 TICK_DEP_BIT_PERF_EVENTS = 1, 111 TICK_DEP_BIT_SCHED = 2, 112 TICK_DEP_BIT_CLOCK_UNSTABLE = 3, 113 TICK_DEP_BIT_RCU = 4, 114 TICK_DEP_BIT_RCU_EXP = 5 115 }; 116 #define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP 117 118 #define TICK_DEP_MASK_NONE 0 119 #define TICK_DEP_MASK_POSIX_TIMER (1 << TICK_DEP_BIT_POSIX_TIMER) 120 #define TICK_DEP_MASK_PERF_EVENTS (1 << TICK_DEP_BIT_PERF_EVENTS) 121 #define TICK_DEP_MASK_SCHED (1 << TICK_DEP_BIT_SCHED) 122 #define TICK_DEP_MASK_CLOCK_UNSTABLE (1 << TICK_DEP_BIT_CLOCK_UNSTABLE) 123 #define TICK_DEP_MASK_RCU (1 << TICK_DEP_BIT_RCU) 124 #define TICK_DEP_MASK_RCU_EXP (1 << TICK_DEP_BIT_RCU_EXP) 125 126 #ifdef CONFIG_NO_HZ_COMMON 127 extern bool tick_nohz_enabled; 128 extern bool tick_nohz_tick_stopped(void); 129 extern bool tick_nohz_tick_stopped_cpu(int cpu); 130 extern void tick_nohz_idle_stop_tick(void); 131 extern void tick_nohz_idle_retain_tick(void); 132 extern void tick_nohz_idle_restart_tick(void); 133 extern void tick_nohz_idle_enter(void); 134 extern void tick_nohz_idle_exit(void); 135 extern void tick_nohz_irq_exit(void); 136 extern bool tick_nohz_idle_got_tick(void); 137 extern ktime_t tick_nohz_get_next_hrtimer(void); 138 extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next); 139 extern unsigned long tick_nohz_get_idle_calls(void); 140 extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu); 141 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 142 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); 143 #else /* !CONFIG_NO_HZ_COMMON */ 144 #define tick_nohz_enabled (0) 145 static inline int tick_nohz_tick_stopped(void) { return 0; } 146 static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; } 147 static inline void tick_nohz_idle_stop_tick(void) { } 148 static inline void tick_nohz_idle_retain_tick(void) { } 149 static inline void tick_nohz_idle_restart_tick(void) { } 150 static inline void tick_nohz_idle_enter(void) { } 151 static inline void tick_nohz_idle_exit(void) { } 152 static inline bool tick_nohz_idle_got_tick(void) { return false; } 153 static inline ktime_t tick_nohz_get_next_hrtimer(void) 154 { 155 /* Next wake up is the tick period, assume it starts now */ 156 return ktime_add(ktime_get(), TICK_NSEC); 157 } 158 static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next) 159 { 160 *delta_next = TICK_NSEC; 161 return *delta_next; 162 } 163 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 164 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } 165 #endif /* !CONFIG_NO_HZ_COMMON */ 166 167 /* 168 * Mask of CPUs that are nohz_full. 169 * 170 * Users should be guarded by CONFIG_NO_HZ_FULL or a tick_nohz_full_cpu() 171 * check. 172 */ 173 extern cpumask_var_t tick_nohz_full_mask; 174 175 #ifdef CONFIG_NO_HZ_FULL 176 extern bool tick_nohz_full_running; 177 178 static inline bool tick_nohz_full_enabled(void) 179 { 180 if (!context_tracking_enabled()) 181 return false; 182 183 return tick_nohz_full_running; 184 } 185 186 /* 187 * Check if a CPU is part of the nohz_full subset. Arrange for evaluating 188 * the cpu expression (typically smp_processor_id()) _after_ the static 189 * key. 190 */ 191 #define tick_nohz_full_cpu(_cpu) ({ \ 192 bool __ret = false; \ 193 if (tick_nohz_full_enabled()) \ 194 __ret = cpumask_test_cpu((_cpu), tick_nohz_full_mask); \ 195 __ret; \ 196 }) 197 198 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) 199 { 200 if (tick_nohz_full_enabled()) 201 cpumask_or(mask, mask, tick_nohz_full_mask); 202 } 203 204 extern void tick_nohz_dep_set(enum tick_dep_bits bit); 205 extern void tick_nohz_dep_clear(enum tick_dep_bits bit); 206 extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit); 207 extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit); 208 extern void tick_nohz_dep_set_task(struct task_struct *tsk, 209 enum tick_dep_bits bit); 210 extern void tick_nohz_dep_clear_task(struct task_struct *tsk, 211 enum tick_dep_bits bit); 212 extern void tick_nohz_dep_set_signal(struct task_struct *tsk, 213 enum tick_dep_bits bit); 214 extern void tick_nohz_dep_clear_signal(struct signal_struct *signal, 215 enum tick_dep_bits bit); 216 extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu); 217 218 /* 219 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases 220 * on top of static keys. 221 */ 222 static inline void tick_dep_set(enum tick_dep_bits bit) 223 { 224 if (tick_nohz_full_enabled()) 225 tick_nohz_dep_set(bit); 226 } 227 228 static inline void tick_dep_clear(enum tick_dep_bits bit) 229 { 230 if (tick_nohz_full_enabled()) 231 tick_nohz_dep_clear(bit); 232 } 233 234 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) 235 { 236 if (tick_nohz_full_cpu(cpu)) 237 tick_nohz_dep_set_cpu(cpu, bit); 238 } 239 240 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) 241 { 242 if (tick_nohz_full_cpu(cpu)) 243 tick_nohz_dep_clear_cpu(cpu, bit); 244 } 245 246 static inline void tick_dep_set_task(struct task_struct *tsk, 247 enum tick_dep_bits bit) 248 { 249 if (tick_nohz_full_enabled()) 250 tick_nohz_dep_set_task(tsk, bit); 251 } 252 static inline void tick_dep_clear_task(struct task_struct *tsk, 253 enum tick_dep_bits bit) 254 { 255 if (tick_nohz_full_enabled()) 256 tick_nohz_dep_clear_task(tsk, bit); 257 } 258 static inline void tick_dep_set_signal(struct task_struct *tsk, 259 enum tick_dep_bits bit) 260 { 261 if (tick_nohz_full_enabled()) 262 tick_nohz_dep_set_signal(tsk, bit); 263 } 264 static inline void tick_dep_clear_signal(struct signal_struct *signal, 265 enum tick_dep_bits bit) 266 { 267 if (tick_nohz_full_enabled()) 268 tick_nohz_dep_clear_signal(signal, bit); 269 } 270 271 extern void tick_nohz_full_kick_cpu(int cpu); 272 extern void __tick_nohz_task_switch(void); 273 extern void __init tick_nohz_full_setup(cpumask_var_t cpumask); 274 #else 275 static inline bool tick_nohz_full_enabled(void) { return false; } 276 static inline bool tick_nohz_full_cpu(int cpu) { return false; } 277 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { } 278 279 static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 280 static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 281 static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; } 282 283 static inline void tick_dep_set(enum tick_dep_bits bit) { } 284 static inline void tick_dep_clear(enum tick_dep_bits bit) { } 285 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 286 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 287 static inline void tick_dep_set_task(struct task_struct *tsk, 288 enum tick_dep_bits bit) { } 289 static inline void tick_dep_clear_task(struct task_struct *tsk, 290 enum tick_dep_bits bit) { } 291 static inline void tick_dep_set_signal(struct task_struct *tsk, 292 enum tick_dep_bits bit) { } 293 static inline void tick_dep_clear_signal(struct signal_struct *signal, 294 enum tick_dep_bits bit) { } 295 296 static inline void tick_nohz_full_kick_cpu(int cpu) { } 297 static inline void __tick_nohz_task_switch(void) { } 298 static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { } 299 #endif 300 301 static inline void tick_nohz_task_switch(void) 302 { 303 if (tick_nohz_full_enabled()) 304 __tick_nohz_task_switch(); 305 } 306 307 static inline void tick_nohz_user_enter_prepare(void) 308 { 309 if (tick_nohz_full_cpu(smp_processor_id())) 310 rcu_nocb_flush_deferred_wakeup(); 311 } 312 313 #endif 314