include/linux/tick.h

   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 #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 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
  28
  29 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_HOTPLUG_CPU)
  30 extern int tick_cpu_dying(unsigned int cpu);
  31 extern void tick_assert_timekeeping_handover(void);
  32 #else
  33 #define tick_cpu_dying  NULL
  34 static inline void tick_assert_timekeeping_handover(void) { }
  35 #endif
  36
  37 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
  38 extern void tick_freeze(void);
  39 extern void tick_unfreeze(void);
  40 #else
  41 static inline void tick_freeze(void) { }
  42 static inline void tick_unfreeze(void) { }
  43 #endif
  44
  45 #ifdef CONFIG_TICK_ONESHOT
  46 extern void tick_irq_enter(void);
  47 #  ifndef arch_needs_cpu
  48 #   define arch_needs_cpu() (0)
  49 #  endif
  50 # else
  51 static inline void tick_irq_enter(void) { }
  52 #endif
  53
  54 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
  55 extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
  56 #else
  57 static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
  58 #endif
  59
  60 enum tick_broadcast_mode {
  61         TICK_BROADCAST_OFF,
  62         TICK_BROADCAST_ON,
  63         TICK_BROADCAST_FORCE,
  64 };
  65
  66 enum tick_broadcast_state {
  67         TICK_BROADCAST_EXIT,
  68         TICK_BROADCAST_ENTER,
  69 };
  70
  71 extern struct static_key_false arch_needs_tick_broadcast;
  72
  73 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  74 extern void tick_broadcast_control(enum tick_broadcast_mode mode);
  75 #else
  76 static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
  77 #endif /* BROADCAST */
  78
  79 #ifdef CONFIG_GENERIC_CLOCKEVENTS
  80 extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
  81 #else
  82 static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
  83 {
  84         return 0;
  85 }
  86 #endif
  87
  88 static inline void tick_broadcast_enable(void)
  89 {
  90         tick_broadcast_control(TICK_BROADCAST_ON);
  91 }
  92 static inline void tick_broadcast_disable(void)
  93 {
  94         tick_broadcast_control(TICK_BROADCAST_OFF);
  95 }
  96 static inline void tick_broadcast_force(void)
  97 {
  98         tick_broadcast_control(TICK_BROADCAST_FORCE);
  99 }
 100 static inline int tick_broadcast_enter(void)
 101 {
 102         return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
 103 }
 104 static inline void tick_broadcast_exit(void)
 105 {
 106         tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
 107 }
 108
 109 enum tick_dep_bits {
 110         TICK_DEP_BIT_POSIX_TIMER        = 0,
 111         TICK_DEP_BIT_PERF_EVENTS        = 1,
 112         TICK_DEP_BIT_SCHED              = 2,
 113         TICK_DEP_BIT_CLOCK_UNSTABLE     = 3,
 114         TICK_DEP_BIT_RCU                = 4,
 115         TICK_DEP_BIT_RCU_EXP            = 5
 116 };
 117 #define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP
 118
 119 #define TICK_DEP_MASK_NONE              0
 120 #define TICK_DEP_MASK_POSIX_TIMER       (1 << TICK_DEP_BIT_POSIX_TIMER)
 121 #define TICK_DEP_MASK_PERF_EVENTS       (1 << TICK_DEP_BIT_PERF_EVENTS)
 122 #define TICK_DEP_MASK_SCHED             (1 << TICK_DEP_BIT_SCHED)
 123 #define TICK_DEP_MASK_CLOCK_UNSTABLE    (1 << TICK_DEP_BIT_CLOCK_UNSTABLE)
 124 #define TICK_DEP_MASK_RCU               (1 << TICK_DEP_BIT_RCU)
 125 #define TICK_DEP_MASK_RCU_EXP           (1 << TICK_DEP_BIT_RCU_EXP)
 126
 127 #ifdef CONFIG_NO_HZ_COMMON
 128 extern bool tick_nohz_enabled;
 129 extern bool tick_nohz_tick_stopped(void);
 130 extern bool tick_nohz_tick_stopped_cpu(int cpu);
 131 extern void tick_nohz_idle_stop_tick(void);
 132 extern void tick_nohz_idle_retain_tick(void);
 133 extern void tick_nohz_idle_restart_tick(void);
 134 extern void tick_nohz_idle_enter(void);
 135 extern void tick_nohz_idle_exit(void);
 136 extern void tick_nohz_irq_exit(void);
 137 extern bool tick_nohz_idle_got_tick(void);
 138 extern ktime_t tick_nohz_get_next_hrtimer(void);
 139 extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next);
 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
 253 static inline void tick_dep_clear_task(struct task_struct *tsk,
 254                                        enum tick_dep_bits bit)
 255 {
 256         if (tick_nohz_full_enabled())
 257                 tick_nohz_dep_clear_task(tsk, bit);
 258 }
 259
 260 static inline void tick_dep_init_task(struct task_struct *tsk)
 261 {
 262         atomic_set(&tsk->tick_dep_mask, 0);
 263 }
 264
 265 static inline void tick_dep_set_signal(struct task_struct *tsk,
 266                                        enum tick_dep_bits bit)
 267 {
 268         if (tick_nohz_full_enabled())
 269                 tick_nohz_dep_set_signal(tsk, bit);
 270 }
 271 static inline void tick_dep_clear_signal(struct signal_struct *signal,
 272                                          enum tick_dep_bits bit)
 273 {
 274         if (tick_nohz_full_enabled())
 275                 tick_nohz_dep_clear_signal(signal, bit);
 276 }
 277
 278 extern void tick_nohz_full_kick_cpu(int cpu);
 279 extern void __tick_nohz_task_switch(void);
 280 extern void __init tick_nohz_full_setup(cpumask_var_t cpumask);
 281 #else
 282 static inline bool tick_nohz_full_enabled(void) { return false; }
 283 static inline bool tick_nohz_full_cpu(int cpu) { return false; }
 284 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
 285
 286 static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
 287 static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
 288 static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; }
 289
 290 static inline void tick_dep_set(enum tick_dep_bits bit) { }
 291 static inline void tick_dep_clear(enum tick_dep_bits bit) { }
 292 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
 293 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
 294 static inline void tick_dep_set_task(struct task_struct *tsk,
 295                                      enum tick_dep_bits bit) { }
 296 static inline void tick_dep_clear_task(struct task_struct *tsk,
 297                                        enum tick_dep_bits bit) { }
 298 static inline void tick_dep_init_task(struct task_struct *tsk) { }
 299 static inline void tick_dep_set_signal(struct task_struct *tsk,
 300                                        enum tick_dep_bits bit) { }
 301 static inline void tick_dep_clear_signal(struct signal_struct *signal,
 302                                          enum tick_dep_bits bit) { }
 303
 304 static inline void tick_nohz_full_kick_cpu(int cpu) { }
 305 static inline void __tick_nohz_task_switch(void) { }
 306 static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { }
 307 #endif
 308
 309 static inline void tick_nohz_task_switch(void)
 310 {
 311         if (tick_nohz_full_enabled())
 312                 __tick_nohz_task_switch();
 313 }
 314
 315 static inline void tick_nohz_user_enter_prepare(void)
 316 {
 317         if (tick_nohz_full_cpu(smp_processor_id()))
 318                 rcu_nocb_flush_deferred_wakeup();
 319 }
 320
 321 #endif