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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - include/linux/rcutiny.h
1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
5 * Copyright IBM Corporation, 2008
7 * Author: Paul E. McKenney <paulmck@linux.ibm.com>
9 * For detailed explanation of Read-Copy Update mechanism see -
12 #ifndef __LINUX_TINY_H
13 #define __LINUX_TINY_H
15 #include <asm/param.h> /* for HZ */
17 /* Never flag non-existent other CPUs! */
18 static inline bool rcu_eqs_special_set(int cpu
) { return false; }
20 unsigned long get_state_synchronize_rcu(void);
21 unsigned long start_poll_synchronize_rcu(void);
22 bool poll_state_synchronize_rcu(unsigned long oldstate
);
24 static inline void cond_synchronize_rcu(unsigned long oldstate
)
29 extern void rcu_barrier(void);
31 static inline void synchronize_rcu_expedited(void)
37 * Add one more declaration of kvfree() here. It is
38 * not so straight forward to just include <linux/mm.h>
39 * where it is defined due to getting many compile
40 * errors caused by that include.
42 extern void kvfree(const void *addr
);
44 static inline void kvfree_call_rcu(struct rcu_head
*head
, rcu_callback_t func
)
51 // kvfree_rcu(one_arg) call.
54 kvfree((void *) func
);
59 static inline void rcu_softirq_qs(void)
64 #define rcu_note_context_switch(preempt) \
67 rcu_tasks_qs(current, (preempt)); \
70 static inline int rcu_needs_cpu(u64 basemono
, u64
*nextevt
)
77 * Take advantage of the fact that there is only one CPU, which
78 * allows us to ignore virtualization-based context switches.
80 static inline void rcu_virt_note_context_switch(int cpu
) { }
81 static inline void rcu_cpu_stall_reset(void) { }
82 static inline int rcu_jiffies_till_stall_check(void) { return 21 * HZ
; }
83 static inline void rcu_idle_enter(void) { }
84 static inline void rcu_idle_exit(void) { }
85 static inline void rcu_irq_enter(void) { }
86 static inline void rcu_irq_exit_irqson(void) { }
87 static inline void rcu_irq_enter_irqson(void) { }
88 static inline void rcu_irq_exit(void) { }
89 static inline void rcu_irq_exit_preempt(void) { }
90 static inline void rcu_irq_exit_check_preempt(void) { }
91 #define rcu_is_idle_cpu(cpu) \
92 (is_idle_task(current) && !in_nmi() && !in_irq() && !in_serving_softirq())
93 static inline void exit_rcu(void) { }
94 static inline bool rcu_preempt_need_deferred_qs(struct task_struct
*t
)
98 static inline void rcu_preempt_deferred_qs(struct task_struct
*t
) { }
100 void rcu_scheduler_starting(void);
101 #else /* #ifndef CONFIG_SRCU */
102 static inline void rcu_scheduler_starting(void) { }
103 #endif /* #else #ifndef CONFIG_SRCU */
104 static inline void rcu_end_inkernel_boot(void) { }
105 static inline bool rcu_inkernel_boot_has_ended(void) { return true; }
106 static inline bool rcu_is_watching(void) { return true; }
107 static inline void rcu_momentary_dyntick_idle(void) { }
108 static inline void kfree_rcu_scheduler_running(void) { }
109 static inline bool rcu_gp_might_be_stalled(void) { return false; }
111 /* Avoid RCU read-side critical sections leaking across. */
112 static inline void rcu_all_qs(void) { barrier(); }
114 /* RCUtree hotplug events */
115 #define rcutree_prepare_cpu NULL
116 #define rcutree_online_cpu NULL
117 #define rcutree_offline_cpu NULL
118 #define rcutree_dead_cpu NULL
119 #define rcutree_dying_cpu NULL
120 static inline void rcu_cpu_starting(unsigned int cpu
) { }
122 #endif /* __LINUX_RCUTINY_H */