[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/kernel/rcupdate.c b/ap/os/linux/linux-3.4.x/kernel/rcupdate.c
new file mode 100644
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--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/kernel/rcupdate.c
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+/*
+ * Read-Copy Update mechanism for mutual exclusion
+ *
+ * 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, 2001
+ *
+ * Authors: Dipankar Sarma <dipankar@in.ibm.com>
+ * Manfred Spraul <manfred@colorfullife.com>
+ *
+ * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
+ * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
+ * Papers:
+ * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf
+ * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ * http://lse.sourceforge.net/locking/rcupdate.html
+ *
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/mutex.h>
+#include <linux/export.h>
+#include <linux/hardirq.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/rcu.h>
+
+#include "rcu.h"
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key rcu_lock_key;
+struct lockdep_map rcu_lock_map =
+ STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
+EXPORT_SYMBOL_GPL(rcu_lock_map);
+
+static struct lock_class_key rcu_bh_lock_key;
+struct lockdep_map rcu_bh_lock_map =
+ STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_bh", &rcu_bh_lock_key);
+EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
+
+static struct lock_class_key rcu_sched_lock_key;
+struct lockdep_map rcu_sched_lock_map =
+ STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_sched", &rcu_sched_lock_key);
+EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
+#endif
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+int debug_lockdep_rcu_enabled(void)
+{
+ return rcu_scheduler_active && debug_locks &&
+ current->lockdep_recursion == 0;
+}
+EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+/**
+ * rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
+ *
+ * Check for bottom half being disabled, which covers both the
+ * CONFIG_PROVE_RCU and not cases. Note that if someone uses
+ * rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled)
+ * will show the situation. This is useful for debug checks in functions
+ * that require that they be called within an RCU read-side critical
+ * section.
+ *
+ * Check debug_lockdep_rcu_enabled() to prevent false positives during boot.
+ *
+ * Note that rcu_read_lock() is disallowed if the CPU is either idle or
+ * offline from an RCU perspective, so check for those as well.
+ */
+int rcu_read_lock_bh_held(void)
+{
+ if (!debug_lockdep_rcu_enabled())
+ return 1;
+ if (rcu_is_cpu_idle())
+ return 0;
+ if (!rcu_lockdep_current_cpu_online())
+ return 0;
+ return in_softirq() || irqs_disabled();
+}
+EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
+#endif
+
+#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+
+struct rcu_synchronize {
+ struct rcu_head head;
+ struct completion completion;
+};
+
+/*
+ * Awaken the corresponding synchronize_rcu() instance now that a
+ * grace period has elapsed.
+ */
+static void wakeme_after_rcu(struct rcu_head *head)
+{
+ struct rcu_synchronize *rcu;
+
+ rcu = container_of(head, struct rcu_synchronize, head);
+ complete(&rcu->completion);
+}
+
+void wait_rcu_gp(call_rcu_func_t crf)
+{
+ struct rcu_synchronize rcu;
+
+ init_rcu_head_on_stack(&rcu.head);
+ init_completion(&rcu.completion);
+ /* Will wake me after RCU finished. */
+ crf(&rcu.head, wakeme_after_rcu);
+ /* Wait for it. */
+ wait_for_completion(&rcu.completion);
+ destroy_rcu_head_on_stack(&rcu.head);
+}
+EXPORT_SYMBOL_GPL(wait_rcu_gp);
+
+#ifdef CONFIG_PROVE_RCU
+/*
+ * wrapper function to avoid #include problems.
+ */
+int rcu_my_thread_group_empty(void)
+{
+ return thread_group_empty(current);
+}
+EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty);
+#endif /* #ifdef CONFIG_PROVE_RCU */
+
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+static inline void debug_init_rcu_head(struct rcu_head *head)
+{
+ debug_object_init(head, &rcuhead_debug_descr);
+}
+
+static inline void debug_rcu_head_free(struct rcu_head *head)
+{
+ debug_object_free(head, &rcuhead_debug_descr);
+}
+
+/*
+ * fixup_init is called when:
+ * - an active object is initialized
+ */
+static int rcuhead_fixup_init(void *addr, enum debug_obj_state state)
+{
+ struct rcu_head *head = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_ACTIVE:
+ /*
+ * Ensure that queued callbacks are all executed.
+ * If we detect that we are nested in a RCU read-side critical
+ * section, we should simply fail, otherwise we would deadlock.
+ * In !PREEMPT configurations, there is no way to tell if we are
+ * in a RCU read-side critical section or not, so we never
+ * attempt any fixup and just print a warning.
+ */
+#ifndef CONFIG_PREEMPT
+ WARN_ON_ONCE(1);
+ return 0;
+#endif
+ if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
+ irqs_disabled()) {
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+ rcu_barrier();
+ rcu_barrier_sched();
+ rcu_barrier_bh();
+ debug_object_init(head, &rcuhead_debug_descr);
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * fixup_activate is called when:
+ * - an active object is activated
+ * - an unknown object is activated (might be a statically initialized object)
+ * Activation is performed internally by call_rcu().
+ */
+static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state)
+{
+ struct rcu_head *head = addr;
+
+ switch (state) {
+
+ case ODEBUG_STATE_NOTAVAILABLE:
+ /*
+ * This is not really a fixup. We just make sure that it is
+ * tracked in the object tracker.
+ */
+ debug_object_init(head, &rcuhead_debug_descr);
+ debug_object_activate(head, &rcuhead_debug_descr);
+ return 0;
+
+ case ODEBUG_STATE_ACTIVE:
+ /*
+ * Ensure that queued callbacks are all executed.
+ * If we detect that we are nested in a RCU read-side critical
+ * section, we should simply fail, otherwise we would deadlock.
+ * In !PREEMPT configurations, there is no way to tell if we are
+ * in a RCU read-side critical section or not, so we never
+ * attempt any fixup and just print a warning.
+ */
+#ifndef CONFIG_PREEMPT
+ WARN_ON_ONCE(1);
+ return 0;
+#endif
+ if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
+ irqs_disabled()) {
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+ rcu_barrier();
+ rcu_barrier_sched();
+ rcu_barrier_bh();
+ debug_object_activate(head, &rcuhead_debug_descr);
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * fixup_free is called when:
+ * - an active object is freed
+ */
+static int rcuhead_fixup_free(void *addr, enum debug_obj_state state)
+{
+ struct rcu_head *head = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_ACTIVE:
+ /*
+ * Ensure that queued callbacks are all executed.
+ * If we detect that we are nested in a RCU read-side critical
+ * section, we should simply fail, otherwise we would deadlock.
+ * In !PREEMPT configurations, there is no way to tell if we are
+ * in a RCU read-side critical section or not, so we never
+ * attempt any fixup and just print a warning.
+ */
+#ifndef CONFIG_PREEMPT
+ WARN_ON_ONCE(1);
+ return 0;
+#endif
+ if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
+ irqs_disabled()) {
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+ rcu_barrier();
+ rcu_barrier_sched();
+ rcu_barrier_bh();
+ debug_object_free(head, &rcuhead_debug_descr);
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/**
+ * init_rcu_head_on_stack() - initialize on-stack rcu_head for debugobjects
+ * @head: pointer to rcu_head structure to be initialized
+ *
+ * This function informs debugobjects of a new rcu_head structure that
+ * has been allocated as an auto variable on the stack. This function
+ * is not required for rcu_head structures that are statically defined or
+ * that are dynamically allocated on the heap. This function has no
+ * effect for !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
+ */
+void init_rcu_head_on_stack(struct rcu_head *head)
+{
+ debug_object_init_on_stack(head, &rcuhead_debug_descr);
+}
+EXPORT_SYMBOL_GPL(init_rcu_head_on_stack);
+
+/**
+ * destroy_rcu_head_on_stack() - destroy on-stack rcu_head for debugobjects
+ * @head: pointer to rcu_head structure to be initialized
+ *
+ * This function informs debugobjects that an on-stack rcu_head structure
+ * is about to go out of scope. As with init_rcu_head_on_stack(), this
+ * function is not required for rcu_head structures that are statically
+ * defined or that are dynamically allocated on the heap. Also as with
+ * init_rcu_head_on_stack(), this function has no effect for
+ * !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
+ */
+void destroy_rcu_head_on_stack(struct rcu_head *head)
+{
+ debug_object_free(head, &rcuhead_debug_descr);
+}
+EXPORT_SYMBOL_GPL(destroy_rcu_head_on_stack);
+
+struct debug_obj_descr rcuhead_debug_descr = {
+ .name = "rcu_head",
+ .fixup_init = rcuhead_fixup_init,
+ .fixup_activate = rcuhead_fixup_activate,
+ .fixup_free = rcuhead_fixup_free,
+};
+EXPORT_SYMBOL_GPL(rcuhead_debug_descr);
+#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+
+#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU) || defined(CONFIG_RCU_TRACE)
+void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp)
+{
+ trace_rcu_torture_read(rcutorturename, rhp);
+}
+EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read);
+#else
+#define do_trace_rcu_torture_read(rcutorturename, rhp) do { } while (0)
+#endif