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- /* SPDX-License-Identifier: GPL-2.0+ */
- /*
- * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
- *
- * Copyright IBM Corporation, 2008
- *
- * Author: Paul E. McKenney <[email protected]>
- *
- * For detailed explanation of Read-Copy Update mechanism see -
- * Documentation/RCU
- */
- #ifndef __LINUX_TINY_H
- #define __LINUX_TINY_H
- #include <asm/param.h> /* for HZ */
- struct rcu_gp_oldstate {
- unsigned long rgos_norm;
- };
- // Maximum number of rcu_gp_oldstate values corresponding to
- // not-yet-completed RCU grace periods.
- #define NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE 2
- /*
- * Are the two oldstate values the same? See the Tree RCU version for
- * docbook header.
- */
- static inline bool same_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp1,
- struct rcu_gp_oldstate *rgosp2)
- {
- return rgosp1->rgos_norm == rgosp2->rgos_norm;
- }
- unsigned long get_state_synchronize_rcu(void);
- static inline void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp)
- {
- rgosp->rgos_norm = get_state_synchronize_rcu();
- }
- unsigned long start_poll_synchronize_rcu(void);
- static inline void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp)
- {
- rgosp->rgos_norm = start_poll_synchronize_rcu();
- }
- bool poll_state_synchronize_rcu(unsigned long oldstate);
- static inline bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp)
- {
- return poll_state_synchronize_rcu(rgosp->rgos_norm);
- }
- static inline void cond_synchronize_rcu(unsigned long oldstate)
- {
- might_sleep();
- }
- static inline void cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp)
- {
- cond_synchronize_rcu(rgosp->rgos_norm);
- }
- static inline unsigned long start_poll_synchronize_rcu_expedited(void)
- {
- return start_poll_synchronize_rcu();
- }
- static inline void start_poll_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp)
- {
- rgosp->rgos_norm = start_poll_synchronize_rcu_expedited();
- }
- static inline void cond_synchronize_rcu_expedited(unsigned long oldstate)
- {
- cond_synchronize_rcu(oldstate);
- }
- static inline void cond_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp)
- {
- cond_synchronize_rcu_expedited(rgosp->rgos_norm);
- }
- extern void rcu_barrier(void);
- static inline void synchronize_rcu_expedited(void)
- {
- synchronize_rcu();
- }
- /*
- * Add one more declaration of kvfree() here. It is
- * not so straight forward to just include <linux/mm.h>
- * where it is defined due to getting many compile
- * errors caused by that include.
- */
- extern void kvfree(const void *addr);
- static inline void __kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
- {
- if (head) {
- call_rcu(head, func);
- return;
- }
- // kvfree_rcu(one_arg) call.
- might_sleep();
- synchronize_rcu();
- kvfree((void *) func);
- }
- #ifdef CONFIG_KASAN_GENERIC
- void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func);
- #else
- static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
- {
- __kvfree_call_rcu(head, func);
- }
- #endif
- void rcu_qs(void);
- static inline void rcu_softirq_qs(void)
- {
- rcu_qs();
- }
- #define rcu_note_context_switch(preempt) \
- do { \
- rcu_qs(); \
- rcu_tasks_qs(current, (preempt)); \
- } while (0)
- static inline int rcu_needs_cpu(void)
- {
- return 0;
- }
- /*
- * Take advantage of the fact that there is only one CPU, which
- * allows us to ignore virtualization-based context switches.
- */
- static inline void rcu_virt_note_context_switch(int cpu) { }
- static inline void rcu_cpu_stall_reset(void) { }
- static inline int rcu_jiffies_till_stall_check(void) { return 21 * HZ; }
- static inline void rcu_irq_exit_check_preempt(void) { }
- #define rcu_is_idle_cpu(cpu) \
- (is_idle_task(current) && !in_nmi() && !in_hardirq() && !in_serving_softirq())
- static inline void exit_rcu(void) { }
- static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t)
- {
- return false;
- }
- static inline void rcu_preempt_deferred_qs(struct task_struct *t) { }
- #ifdef CONFIG_SRCU
- void rcu_scheduler_starting(void);
- #else /* #ifndef CONFIG_SRCU */
- static inline void rcu_scheduler_starting(void) { }
- #endif /* #else #ifndef CONFIG_SRCU */
- static inline void rcu_end_inkernel_boot(void) { }
- static inline bool rcu_inkernel_boot_has_ended(void) { return true; }
- static inline bool rcu_is_watching(void) { return true; }
- static inline void rcu_momentary_dyntick_idle(void) { }
- static inline void kfree_rcu_scheduler_running(void) { }
- static inline bool rcu_gp_might_be_stalled(void) { return false; }
- /* Avoid RCU read-side critical sections leaking across. */
- static inline void rcu_all_qs(void) { barrier(); }
- /* RCUtree hotplug events */
- #define rcutree_prepare_cpu NULL
- #define rcutree_online_cpu NULL
- #define rcutree_offline_cpu NULL
- #define rcutree_dead_cpu NULL
- #define rcutree_dying_cpu NULL
- static inline void rcu_cpu_starting(unsigned int cpu) { }
- #endif /* __LINUX_RCUTINY_H */
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