diff options
Diffstat (limited to 'include/linux/rcutiny.h')
| -rw-r--r-- | include/linux/rcutiny.h | 161 |
1 files changed, 85 insertions, 76 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index e31005ee339e..f519cd680228 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * * Copyright IBM Corporation, 2008 * - * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Author: Paul E. McKenney <paulmck@linux.ibm.com> * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU @@ -25,111 +12,133 @@ #ifndef __LINUX_TINY_H #define __LINUX_TINY_H -#include <linux/cache.h> +#include <asm/param.h> /* for HZ */ -static inline void rcu_barrier_bh(void) -{ - wait_rcu_gp(call_rcu_bh); -} +struct rcu_gp_oldstate { + unsigned long rgos_norm; +}; -static inline void rcu_barrier_sched(void) -{ - wait_rcu_gp(call_rcu_sched); -} +// Maximum number of rcu_gp_oldstate values corresponding to +// not-yet-completed RCU grace periods. +#define NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE 2 -static inline void synchronize_rcu_expedited(void) +/* + * 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) { - synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */ + return rgosp1->rgos_norm == rgosp2->rgos_norm; } -static inline void rcu_barrier(void) -{ - rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */ -} +unsigned long get_state_synchronize_rcu(void); -static inline void synchronize_rcu_bh(void) +static inline void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) { - synchronize_sched(); + rgosp->rgos_norm = get_state_synchronize_rcu(); } -static inline void synchronize_rcu_bh_expedited(void) -{ - synchronize_sched(); -} +unsigned long start_poll_synchronize_rcu(void); -static inline void synchronize_sched_expedited(void) +static inline void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) { - synchronize_sched(); + rgosp->rgos_norm = start_poll_synchronize_rcu(); } -static inline void kfree_call_rcu(struct rcu_head *head, - void (*func)(struct rcu_head *rcu)) -{ - call_rcu(head, func); -} +bool poll_state_synchronize_rcu(unsigned long oldstate); -static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) +static inline bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) { - *delta_jiffies = ULONG_MAX; - return 0; + return poll_state_synchronize_rcu(rgosp->rgos_norm); } -static inline void rcu_note_context_switch(int cpu) +static inline void cond_synchronize_rcu(unsigned long oldstate) { - rcu_sched_qs(cpu); + might_sleep(); } -/* - * 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 cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) { + cond_synchronize_rcu(rgosp->rgos_norm); } -/* - * Return the number of grace periods. - */ -static inline long rcu_batches_completed(void) +static inline unsigned long start_poll_synchronize_rcu_expedited(void) { - return 0; + return start_poll_synchronize_rcu(); } -/* - * Return the number of bottom-half grace periods. - */ -static inline long rcu_batches_completed_bh(void) +static inline void start_poll_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp) { - return 0; + rgosp->rgos_norm = start_poll_synchronize_rcu_expedited(); } -static inline void rcu_force_quiescent_state(void) +static inline void cond_synchronize_rcu_expedited(unsigned long oldstate) { + cond_synchronize_rcu(oldstate); } -static inline void rcu_bh_force_quiescent_state(void) +static inline void cond_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp) { + cond_synchronize_rcu_expedited(rgosp->rgos_norm); } -static inline void rcu_sched_force_quiescent_state(void) -{ -} +extern void rcu_barrier(void); -static inline void rcu_cpu_stall_reset(void) +static inline void synchronize_rcu_expedited(void) { + synchronize_rcu(); } -static inline void exit_rcu(void) +void rcu_qs(void); + +static inline void rcu_softirq_qs(void) { + rcu_qs(); } -#ifdef CONFIG_DEBUG_LOCK_ALLOC -extern int rcu_scheduler_active __read_mostly; -extern void rcu_scheduler_starting(void); -#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ -static inline void rcu_scheduler_starting(void) +#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; } -#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ + +static inline void rcu_request_urgent_qs_task(struct task_struct *t) { } + +/* + * 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(void) { } +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) { } +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) { } +void rcu_scheduler_starting(void); +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_eqs(void) { } + +/* 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 rcutree_report_cpu_starting(unsigned int cpu) { } #endif /* __LINUX_RCUTINY_H */ |