rcu: Move RCU-related source code to kernel/rcu directory

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 0 insertions, 388 deletions

diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
deleted file mode 100644
index 312e9709713f..000000000000
--- a/kernel/rcutiny.c
+++ /dev/null
@@ -1,388 +0,0 @@
-/*
- * 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>
- *
- * For detailed explanation of Read-Copy Update mechanism see -
- *		Documentation/RCU
- */
-#include <linux/completion.h>
-#include <linux/interrupt.h>
-#include <linux/notifier.h>
-#include <linux/rcupdate.h>
-#include <linux/kernel.h>
-#include <linux/export.h>
-#include <linux/mutex.h>
-#include <linux/sched.h>
-#include <linux/types.h>
-#include <linux/init.h>
-#include <linux/time.h>
-#include <linux/cpu.h>
-#include <linux/prefetch.h>
-#include <linux/ftrace_event.h>
-
-#ifdef CONFIG_RCU_TRACE
-#include <trace/events/rcu.h>
-#endif /* #else #ifdef CONFIG_RCU_TRACE */
-
-#include "rcu.h"
-
-/* Forward declarations for rcutiny_plugin.h. */
-struct rcu_ctrlblk;
-static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp);
-static void rcu_process_callbacks(struct softirq_action *unused);
-static void __call_rcu(struct rcu_head *head,
-		       void (*func)(struct rcu_head *rcu),
-		       struct rcu_ctrlblk *rcp);
-
-static long long rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
-
-#include "rcutiny_plugin.h"
-
-/* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */
-static void rcu_idle_enter_common(long long newval)
-{
-	if (newval) {
-		RCU_TRACE(trace_rcu_dyntick(TPS("--="),
-					    rcu_dynticks_nesting, newval));
-		rcu_dynticks_nesting = newval;
-		return;
-	}
-	RCU_TRACE(trace_rcu_dyntick(TPS("Start"),
-				    rcu_dynticks_nesting, newval));
-	if (!is_idle_task(current)) {
-		struct task_struct *idle = idle_task(smp_processor_id());
-
-		RCU_TRACE(trace_rcu_dyntick(TPS("Entry error: not idle task"),
-					    rcu_dynticks_nesting, newval));
-		ftrace_dump(DUMP_ALL);
-		WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
-			  current->pid, current->comm,
-			  idle->pid, idle->comm); /* must be idle task! */
-	}
-	rcu_sched_qs(0); /* implies rcu_bh_qsctr_inc(0) */
-	barrier();
-	rcu_dynticks_nesting = newval;
-}
-
-/*
- * Enter idle, which is an extended quiescent state if we have fully
- * entered that mode (i.e., if the new value of dynticks_nesting is zero).
- */
-void rcu_idle_enter(void)
-{
-	unsigned long flags;
-	long long newval;
-
-	local_irq_save(flags);
-	WARN_ON_ONCE((rcu_dynticks_nesting & DYNTICK_TASK_NEST_MASK) == 0);
-	if ((rcu_dynticks_nesting & DYNTICK_TASK_NEST_MASK) ==
-	    DYNTICK_TASK_NEST_VALUE)
-		newval = 0;
-	else
-		newval = rcu_dynticks_nesting - DYNTICK_TASK_NEST_VALUE;
-	rcu_idle_enter_common(newval);
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(rcu_idle_enter);
-
-/*
- * Exit an interrupt handler towards idle.
- */
-void rcu_irq_exit(void)
-{
-	unsigned long flags;
-	long long newval;
-
-	local_irq_save(flags);
-	newval = rcu_dynticks_nesting - 1;
-	WARN_ON_ONCE(newval < 0);
-	rcu_idle_enter_common(newval);
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(rcu_irq_exit);
-
-/* Common code for rcu_idle_exit() and rcu_irq_enter(), see kernel/rcutree.c. */
-static void rcu_idle_exit_common(long long oldval)
-{
-	if (oldval) {
-		RCU_TRACE(trace_rcu_dyntick(TPS("++="),
-					    oldval, rcu_dynticks_nesting));
-		return;
-	}
-	RCU_TRACE(trace_rcu_dyntick(TPS("End"), oldval, rcu_dynticks_nesting));
-	if (!is_idle_task(current)) {
-		struct task_struct *idle = idle_task(smp_processor_id());
-
-		RCU_TRACE(trace_rcu_dyntick(TPS("Exit error: not idle task"),
-			  oldval, rcu_dynticks_nesting));
-		ftrace_dump(DUMP_ALL);
-		WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
-			  current->pid, current->comm,
-			  idle->pid, idle->comm); /* must be idle task! */
-	}
-}
-
-/*
- * Exit idle, so that we are no longer in an extended quiescent state.
- */
-void rcu_idle_exit(void)
-{
-	unsigned long flags;
-	long long oldval;
-
-	local_irq_save(flags);
-	oldval = rcu_dynticks_nesting;
-	WARN_ON_ONCE(rcu_dynticks_nesting < 0);
-	if (rcu_dynticks_nesting & DYNTICK_TASK_NEST_MASK)
-		rcu_dynticks_nesting += DYNTICK_TASK_NEST_VALUE;
-	else
-		rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
-	rcu_idle_exit_common(oldval);
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(rcu_idle_exit);
-
-/*
- * Enter an interrupt handler, moving away from idle.
- */
-void rcu_irq_enter(void)
-{
-	unsigned long flags;
-	long long oldval;
-
-	local_irq_save(flags);
-	oldval = rcu_dynticks_nesting;
-	rcu_dynticks_nesting++;
-	WARN_ON_ONCE(rcu_dynticks_nesting == 0);
-	rcu_idle_exit_common(oldval);
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(rcu_irq_enter);
-
-#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
-
-/*
- * Test whether RCU thinks that the current CPU is idle.
- */
-bool __rcu_is_watching(void)
-{
-	return rcu_dynticks_nesting;
-}
-EXPORT_SYMBOL(__rcu_is_watching);
-
-#endif /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
-
-/*
- * Test whether the current CPU was interrupted from idle.  Nested
- * interrupts don't count, we must be running at the first interrupt
- * level.
- */
-static int rcu_is_cpu_rrupt_from_idle(void)
-{
-	return rcu_dynticks_nesting <= 1;
-}
-
-/*
- * Helper function for rcu_sched_qs() and rcu_bh_qs().
- * Also irqs are disabled to avoid confusion due to interrupt handlers
- * invoking call_rcu().
- */
-static int rcu_qsctr_help(struct rcu_ctrlblk *rcp)
-{
-	RCU_TRACE(reset_cpu_stall_ticks(rcp));
-	if (rcp->rcucblist != NULL &&
-	    rcp->donetail != rcp->curtail) {
-		rcp->donetail = rcp->curtail;
-		return 1;
-	}
-
-	return 0;
-}
-
-/*
- * Record an rcu quiescent state.  And an rcu_bh quiescent state while we
- * are at it, given that any rcu quiescent state is also an rcu_bh
- * quiescent state.  Use "+" instead of "||" to defeat short circuiting.
- */
-void rcu_sched_qs(int cpu)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	if (rcu_qsctr_help(&rcu_sched_ctrlblk) +
-	    rcu_qsctr_help(&rcu_bh_ctrlblk))
-		raise_softirq(RCU_SOFTIRQ);
-	local_irq_restore(flags);
-}
-
-/*
- * Record an rcu_bh quiescent state.
- */
-void rcu_bh_qs(int cpu)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	if (rcu_qsctr_help(&rcu_bh_ctrlblk))
-		raise_softirq(RCU_SOFTIRQ);
-	local_irq_restore(flags);
-}
-
-/*
- * Check to see if the scheduling-clock interrupt came from an extended
- * quiescent state, and, if so, tell RCU about it.  This function must
- * be called from hardirq context.  It is normally called from the
- * scheduling-clock interrupt.
- */
-void rcu_check_callbacks(int cpu, int user)
-{
-	RCU_TRACE(check_cpu_stalls());
-	if (user || rcu_is_cpu_rrupt_from_idle())
-		rcu_sched_qs(cpu);
-	else if (!in_softirq())
-		rcu_bh_qs(cpu);
-}
-
-/*
- * Invoke the RCU callbacks on the specified rcu_ctrlkblk structure
- * whose grace period has elapsed.
- */
-static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
-{
-	const char *rn = NULL;
-	struct rcu_head *next, *list;
-	unsigned long flags;
-	RCU_TRACE(int cb_count = 0);
-
-	/* If no RCU callbacks ready to invoke, just return. */
-	if (&rcp->rcucblist == rcp->donetail) {
-		RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, 0, -1));
-		RCU_TRACE(trace_rcu_batch_end(rcp->name, 0,
-					      !!ACCESS_ONCE(rcp->rcucblist),
-					      need_resched(),
-					      is_idle_task(current),
-					      false));
-		return;
-	}
-
-	/* Move the ready-to-invoke callbacks to a local list. */
-	local_irq_save(flags);
-	RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, rcp->qlen, -1));
-	list = rcp->rcucblist;
-	rcp->rcucblist = *rcp->donetail;
-	*rcp->donetail = NULL;
-	if (rcp->curtail == rcp->donetail)
-		rcp->curtail = &rcp->rcucblist;
-	rcp->donetail = &rcp->rcucblist;
-	local_irq_restore(flags);
-
-	/* Invoke the callbacks on the local list. */
-	RCU_TRACE(rn = rcp->name);
-	while (list) {
-		next = list->next;
-		prefetch(next);
-		debug_rcu_head_unqueue(list);
-		local_bh_disable();
-		__rcu_reclaim(rn, list);
-		local_bh_enable();
-		list = next;
-		RCU_TRACE(cb_count++);
-	}
-	RCU_TRACE(rcu_trace_sub_qlen(rcp, cb_count));
-	RCU_TRACE(trace_rcu_batch_end(rcp->name,
-				      cb_count, 0, need_resched(),
-				      is_idle_task(current),
-				      false));
-}
-
-static void rcu_process_callbacks(struct softirq_action *unused)
-{
-	__rcu_process_callbacks(&rcu_sched_ctrlblk);
-	__rcu_process_callbacks(&rcu_bh_ctrlblk);
-}
-
-/*
- * Wait for a grace period to elapse.  But it is illegal to invoke
- * synchronize_sched() from within an RCU read-side critical section.
- * Therefore, any legal call to synchronize_sched() is a quiescent
- * state, and so on a UP system, synchronize_sched() need do nothing.
- * Ditto for synchronize_rcu_bh().  (But Lai Jiangshan points out the
- * benefits of doing might_sleep() to reduce latency.)
- *
- * Cool, huh?  (Due to Josh Triplett.)
- *
- * But we want to make this a static inline later.  The cond_resched()
- * currently makes this problematic.
- */
-void synchronize_sched(void)
-{
-	rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) &&
-			   !lock_is_held(&rcu_lock_map) &&
-			   !lock_is_held(&rcu_sched_lock_map),
-			   "Illegal synchronize_sched() in RCU read-side critical section");
-	cond_resched();
-}
-EXPORT_SYMBOL_GPL(synchronize_sched);
-
-/*
- * Helper function for call_rcu() and call_rcu_bh().
- */
-static void __call_rcu(struct rcu_head *head,
-		       void (*func)(struct rcu_head *rcu),
-		       struct rcu_ctrlblk *rcp)
-{
-	unsigned long flags;
-
-	debug_rcu_head_queue(head);
-	head->func = func;
-	head->next = NULL;
-
-	local_irq_save(flags);
-	*rcp->curtail = head;
-	rcp->curtail = &head->next;
-	RCU_TRACE(rcp->qlen++);
-	local_irq_restore(flags);
-}
-
-/*
- * Post an RCU callback to be invoked after the end of an RCU-sched grace
- * period.  But since we have but one CPU, that would be after any
- * quiescent state.
- */
-void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
-{
-	__call_rcu(head, func, &rcu_sched_ctrlblk);
-}
-EXPORT_SYMBOL_GPL(call_rcu_sched);
-
-/*
- * Post an RCU bottom-half callback to be invoked after any subsequent
- * quiescent state.
- */
-void call_rcu_bh(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
-{
-	__call_rcu(head, func, &rcu_bh_ctrlblk);
-}
-EXPORT_SYMBOL_GPL(call_rcu_bh);
-
-void rcu_init(void)
-{
-	open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
-}