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-rw-r--r--kernel/rcu/rcu.h277
1 files changed, 277 insertions, 0 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 73e16ec4054b..808b8c85f626 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -212,6 +212,18 @@ int rcu_jiffies_till_stall_check(void);
*/
#define TPS(x) tracepoint_string(x)
+/*
+ * Dump the ftrace buffer, but only one time per callsite per boot.
+ */
+#define rcu_ftrace_dump(oops_dump_mode) \
+do { \
+ static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \
+ \
+ if (!atomic_read(&___rfd_beenhere) && \
+ !atomic_xchg(&___rfd_beenhere, 1)) \
+ ftrace_dump(oops_dump_mode); \
+} while (0)
+
void rcu_early_boot_tests(void);
void rcu_test_sync_prims(void);
@@ -291,6 +303,271 @@ static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
cpu <= rnp->grphi; \
cpu = cpumask_next((cpu), cpu_possible_mask))
+/*
+ * Wrappers for the rcu_node::lock acquire and release.
+ *
+ * Because the rcu_nodes form a tree, the tree traversal locking will observe
+ * different lock values, this in turn means that an UNLOCK of one level
+ * followed by a LOCK of another level does not imply a full memory barrier;
+ * and most importantly transitivity is lost.
+ *
+ * In order to restore full ordering between tree levels, augment the regular
+ * lock acquire functions with smp_mb__after_unlock_lock().
+ *
+ * As ->lock of struct rcu_node is a __private field, therefore one should use
+ * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock.
+ */
+#define raw_spin_lock_rcu_node(p) \
+do { \
+ raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \
+ smp_mb__after_unlock_lock(); \
+} while (0)
+
+#define raw_spin_unlock_rcu_node(p) raw_spin_unlock(&ACCESS_PRIVATE(p, lock))
+
+#define raw_spin_lock_irq_rcu_node(p) \
+do { \
+ raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \
+ smp_mb__after_unlock_lock(); \
+} while (0)
+
+#define raw_spin_unlock_irq_rcu_node(p) \
+ raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock))
+
+#define raw_spin_lock_irqsave_rcu_node(p, flags) \
+do { \
+ raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \
+ smp_mb__after_unlock_lock(); \
+} while (0)
+
+#define raw_spin_unlock_irqrestore_rcu_node(p, flags) \
+ raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags) \
+
+#define raw_spin_trylock_rcu_node(p) \
+({ \
+ bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \
+ \
+ if (___locked) \
+ smp_mb__after_unlock_lock(); \
+ ___locked; \
+})
+
#endif /* #if defined(SRCU) || !defined(TINY_RCU) */
+#ifdef CONFIG_TINY_RCU
+/* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */
+static inline bool rcu_gp_is_normal(void) /* Internal RCU use. */
+{
+ return true;
+}
+static inline bool rcu_gp_is_expedited(void) /* Internal RCU use. */
+{
+ return false;
+}
+
+static inline void rcu_expedite_gp(void)
+{
+}
+
+static inline void rcu_unexpedite_gp(void)
+{
+}
+#else /* #ifdef CONFIG_TINY_RCU */
+bool rcu_gp_is_normal(void); /* Internal RCU use. */
+bool rcu_gp_is_expedited(void); /* Internal RCU use. */
+void rcu_expedite_gp(void);
+void rcu_unexpedite_gp(void);
+void rcupdate_announce_bootup_oddness(void);
+#endif /* #else #ifdef CONFIG_TINY_RCU */
+
+#define RCU_SCHEDULER_INACTIVE 0
+#define RCU_SCHEDULER_INIT 1
+#define RCU_SCHEDULER_RUNNING 2
+
+#ifdef CONFIG_TINY_RCU
+static inline void rcu_request_urgent_qs_task(struct task_struct *t) { }
+#else /* #ifdef CONFIG_TINY_RCU */
+void rcu_request_urgent_qs_task(struct task_struct *t);
+#endif /* #else #ifdef CONFIG_TINY_RCU */
+
+enum rcutorture_type {
+ RCU_FLAVOR,
+ RCU_BH_FLAVOR,
+ RCU_SCHED_FLAVOR,
+ RCU_TASKS_FLAVOR,
+ SRCU_FLAVOR,
+ INVALID_RCU_FLAVOR
+};
+
+#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
+void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
+ unsigned long *gpnum, unsigned long *completed);
+void rcutorture_record_test_transition(void);
+void rcutorture_record_progress(unsigned long vernum);
+void do_trace_rcu_torture_read(const char *rcutorturename,
+ struct rcu_head *rhp,
+ unsigned long secs,
+ unsigned long c_old,
+ unsigned long c);
+#else
+static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
+ int *flags,
+ unsigned long *gpnum,
+ unsigned long *completed)
+{
+ *flags = 0;
+ *gpnum = 0;
+ *completed = 0;
+}
+static inline void rcutorture_record_test_transition(void)
+{
+}
+static inline void rcutorture_record_progress(unsigned long vernum)
+{
+}
+#ifdef CONFIG_RCU_TRACE
+void do_trace_rcu_torture_read(const char *rcutorturename,
+ struct rcu_head *rhp,
+ unsigned long secs,
+ unsigned long c_old,
+ unsigned long c);
+#else
+#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
+ do { } while (0)
+#endif
+#endif
+
+#ifdef CONFIG_TINY_SRCU
+
+static inline void srcutorture_get_gp_data(enum rcutorture_type test_type,
+ struct srcu_struct *sp, int *flags,
+ unsigned long *gpnum,
+ unsigned long *completed)
+{
+ if (test_type != SRCU_FLAVOR)
+ return;
+ *flags = 0;
+ *completed = sp->srcu_idx;
+ *gpnum = *completed;
+}
+
+#elif defined(CONFIG_TREE_SRCU)
+
+void srcutorture_get_gp_data(enum rcutorture_type test_type,
+ struct srcu_struct *sp, int *flags,
+ unsigned long *gpnum, unsigned long *completed);
+
+#endif
+
+#ifdef CONFIG_TINY_RCU
+
+/*
+ * Return the number of grace periods started.
+ */
+static inline unsigned long rcu_batches_started(void)
+{
+ return 0;
+}
+
+/*
+ * Return the number of bottom-half grace periods started.
+ */
+static inline unsigned long rcu_batches_started_bh(void)
+{
+ return 0;
+}
+
+/*
+ * Return the number of sched grace periods started.
+ */
+static inline unsigned long rcu_batches_started_sched(void)
+{
+ return 0;
+}
+
+/*
+ * Return the number of grace periods completed.
+ */
+static inline unsigned long rcu_batches_completed(void)
+{
+ return 0;
+}
+
+/*
+ * Return the number of bottom-half grace periods completed.
+ */
+static inline unsigned long rcu_batches_completed_bh(void)
+{
+ return 0;
+}
+
+/*
+ * Return the number of sched grace periods completed.
+ */
+static inline unsigned long rcu_batches_completed_sched(void)
+{
+ return 0;
+}
+
+/*
+ * Return the number of expedited grace periods completed.
+ */
+static inline unsigned long rcu_exp_batches_completed(void)
+{
+ return 0;
+}
+
+/*
+ * Return the number of expedited sched grace periods completed.
+ */
+static inline unsigned long rcu_exp_batches_completed_sched(void)
+{
+ return 0;
+}
+
+static inline unsigned long srcu_batches_completed(struct srcu_struct *sp)
+{
+ return 0;
+}
+
+static inline void rcu_force_quiescent_state(void)
+{
+}
+
+static inline void rcu_bh_force_quiescent_state(void)
+{
+}
+
+static inline void rcu_sched_force_quiescent_state(void)
+{
+}
+
+static inline void show_rcu_gp_kthreads(void)
+{
+}
+
+#else /* #ifdef CONFIG_TINY_RCU */
+extern unsigned long rcutorture_testseq;
+extern unsigned long rcutorture_vernum;
+unsigned long rcu_batches_started(void);
+unsigned long rcu_batches_started_bh(void);
+unsigned long rcu_batches_started_sched(void);
+unsigned long rcu_batches_completed(void);
+unsigned long rcu_batches_completed_bh(void);
+unsigned long rcu_batches_completed_sched(void);
+unsigned long rcu_exp_batches_completed(void);
+unsigned long rcu_exp_batches_completed_sched(void);
+unsigned long srcu_batches_completed(struct srcu_struct *sp);
+void show_rcu_gp_kthreads(void);
+void rcu_force_quiescent_state(void);
+void rcu_bh_force_quiescent_state(void);
+void rcu_sched_force_quiescent_state(void);
+#endif /* #else #ifdef CONFIG_TINY_RCU */
+
+#ifdef CONFIG_RCU_NOCB_CPU
+bool rcu_is_nocb_cpu(int cpu);
+#else
+static inline bool rcu_is_nocb_cpu(int cpu) { return false; }
+#endif
+
#endif /* __LINUX_RCU_H */