root/include/linux/rcutiny.h

INCLUDED FROM

DEFINITIONS

1. rcu_eqs_special_set
2. get_state_synchronize_rcu
3. cond_synchronize_rcu
4. synchronize_rcu_expedited
5. kfree_call_rcu
6. rcu_softirq_qs
7. rcu_needs_cpu
8. rcu_virt_note_context_switch
9. rcu_cpu_stall_reset
10. rcu_jiffies_till_stall_check
11. rcu_idle_enter
12. rcu_idle_exit
13. rcu_irq_enter
14. rcu_irq_exit_irqson
15. rcu_irq_enter_irqson
16. rcu_irq_exit
17. exit_rcu
18. rcu_preempt_need_deferred_qs
19. rcu_preempt_deferred_qs
20. rcu_scheduler_starting
21. rcu_end_inkernel_boot
22. rcu_is_watching
23. rcu_all_qs
24. rcu_cpu_starting

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
   4  *
   5  * Copyright IBM Corporation, 2008
   6  *
   7  * Author: Paul E. McKenney <paulmck@linux.ibm.com>
   8  *
   9  * For detailed explanation of Read-Copy Update mechanism see -
  10  *              Documentation/RCU
  11  */
  12 #ifndef __LINUX_TINY_H
  13 #define __LINUX_TINY_H
  14 
  15 #include <asm/param.h> /* for HZ */
  16 
  17 /* Never flag non-existent other CPUs! */
  18 static inline bool rcu_eqs_special_set(int cpu) { return false; }
  19 
  20 static inline unsigned long get_state_synchronize_rcu(void)
  21 {
  22         return 0;
  23 }
  24 
  25 static inline void cond_synchronize_rcu(unsigned long oldstate)
  26 {
  27         might_sleep();
  28 }
  29 
  30 extern void rcu_barrier(void);
  31 
  32 static inline void synchronize_rcu_expedited(void)
  33 {
  34         synchronize_rcu();
  35 }
  36 
  37 static inline void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
  38 {
  39         call_rcu(head, func);
  40 }
  41 
  42 void rcu_qs(void);
  43 
  44 static inline void rcu_softirq_qs(void)
  45 {
  46         rcu_qs();
  47 }
  48 
  49 #define rcu_note_context_switch(preempt) \
  50         do { \
  51                 rcu_qs(); \
  52                 rcu_tasks_qs(current); \
  53         } while (0)
  54 
  55 static inline int rcu_needs_cpu(u64 basemono, u64 *nextevt)
  56 {
  57         *nextevt = KTIME_MAX;
  58         return 0;
  59 }
  60 
  61 /*
  62  * Take advantage of the fact that there is only one CPU, which
  63  * allows us to ignore virtualization-based context switches.
  64  */
  65 static inline void rcu_virt_note_context_switch(int cpu) { }
  66 static inline void rcu_cpu_stall_reset(void) { }
  67 static inline int rcu_jiffies_till_stall_check(void) { return 21 * HZ; }
  68 static inline void rcu_idle_enter(void) { }
  69 static inline void rcu_idle_exit(void) { }
  70 static inline void rcu_irq_enter(void) { }
  71 static inline void rcu_irq_exit_irqson(void) { }
  72 static inline void rcu_irq_enter_irqson(void) { }
  73 static inline void rcu_irq_exit(void) { }
  74 static inline void exit_rcu(void) { }
  75 static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t)
  76 {
  77         return false;
  78 }
  79 static inline void rcu_preempt_deferred_qs(struct task_struct *t) { }
  80 #ifdef CONFIG_SRCU
  81 void rcu_scheduler_starting(void);
  82 #else /* #ifndef CONFIG_SRCU */
  83 static inline void rcu_scheduler_starting(void) { }
  84 #endif /* #else #ifndef CONFIG_SRCU */
  85 static inline void rcu_end_inkernel_boot(void) { }
  86 static inline bool rcu_is_watching(void) { return true; }
  87 
  88 /* Avoid RCU read-side critical sections leaking across. */
  89 static inline void rcu_all_qs(void) { barrier(); }
  90 
  91 /* RCUtree hotplug events */
  92 #define rcutree_prepare_cpu      NULL
  93 #define rcutree_online_cpu       NULL
  94 #define rcutree_offline_cpu      NULL
  95 #define rcutree_dead_cpu         NULL
  96 #define rcutree_dying_cpu        NULL
  97 static inline void rcu_cpu_starting(unsigned int cpu) { }
  98 
  99 #endif /* __LINUX_RCUTINY_H */