Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 538 insertions, 0 deletions

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
new file mode 100644
index 000000000..fcf95d1ee
--- /dev/null
+++ b/kernel/rcu/rcu.h
@@ -0,0 +1,538 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Read-Copy Update definitions shared among RCU implementations.
+ *
+ * Copyright IBM Corporation, 2011
+ *
+ * Author: Paul E. McKenney <paulmck@linux.ibm.com>
+ */
+
+#ifndef __LINUX_RCU_H
+#define __LINUX_RCU_H
+
+#include <trace/events/rcu.h>
+
+/* Offset to allow distinguishing irq vs. task-based idle entry/exit. */
+#define DYNTICK_IRQ_NONIDLE	((LONG_MAX / 2) + 1)
+
+
+/*
+ * Grace-period counter management.
+ */
+
+#define RCU_SEQ_CTR_SHIFT	2
+#define RCU_SEQ_STATE_MASK	((1 << RCU_SEQ_CTR_SHIFT) - 1)
+
+/*
+ * Return the counter portion of a sequence number previously returned
+ * by rcu_seq_snap() or rcu_seq_current().
+ */
+static inline unsigned long rcu_seq_ctr(unsigned long s)
+{
+	return s >> RCU_SEQ_CTR_SHIFT;
+}
+
+/*
+ * Return the state portion of a sequence number previously returned
+ * by rcu_seq_snap() or rcu_seq_current().
+ */
+static inline int rcu_seq_state(unsigned long s)
+{
+	return s & RCU_SEQ_STATE_MASK;
+}
+
+/*
+ * Set the state portion of the pointed-to sequence number.
+ * The caller is responsible for preventing conflicting updates.
+ */
+static inline void rcu_seq_set_state(unsigned long *sp, int newstate)
+{
+	WARN_ON_ONCE(newstate & ~RCU_SEQ_STATE_MASK);
+	WRITE_ONCE(*sp, (*sp & ~RCU_SEQ_STATE_MASK) + newstate);
+}
+
+/* Adjust sequence number for start of update-side operation. */
+static inline void rcu_seq_start(unsigned long *sp)
+{
+	WRITE_ONCE(*sp, *sp + 1);
+	smp_mb(); /* Ensure update-side operation after counter increment. */
+	WARN_ON_ONCE(rcu_seq_state(*sp) != 1);
+}
+
+/* Compute the end-of-grace-period value for the specified sequence number. */
+static inline unsigned long rcu_seq_endval(unsigned long *sp)
+{
+	return (*sp | RCU_SEQ_STATE_MASK) + 1;
+}
+
+/* Adjust sequence number for end of update-side operation. */
+static inline void rcu_seq_end(unsigned long *sp)
+{
+	smp_mb(); /* Ensure update-side operation before counter increment. */
+	WARN_ON_ONCE(!rcu_seq_state(*sp));
+	WRITE_ONCE(*sp, rcu_seq_endval(sp));
+}
+
+/*
+ * rcu_seq_snap - Take a snapshot of the update side's sequence number.
+ *
+ * This function returns the earliest value of the grace-period sequence number
+ * that will indicate that a full grace period has elapsed since the current
+ * time.  Once the grace-period sequence number has reached this value, it will
+ * be safe to invoke all callbacks that have been registered prior to the
+ * current time. This value is the current grace-period number plus two to the
+ * power of the number of low-order bits reserved for state, then rounded up to
+ * the next value in which the state bits are all zero.
+ */
+static inline unsigned long rcu_seq_snap(unsigned long *sp)
+{
+	unsigned long s;
+
+	s = (READ_ONCE(*sp) + 2 * RCU_SEQ_STATE_MASK + 1) & ~RCU_SEQ_STATE_MASK;
+	smp_mb(); /* Above access must not bleed into critical section. */
+	return s;
+}
+
+/* Return the current value the update side's sequence number, no ordering. */
+static inline unsigned long rcu_seq_current(unsigned long *sp)
+{
+	return READ_ONCE(*sp);
+}
+
+/*
+ * Given a snapshot from rcu_seq_snap(), determine whether or not the
+ * corresponding update-side operation has started.
+ */
+static inline bool rcu_seq_started(unsigned long *sp, unsigned long s)
+{
+	return ULONG_CMP_LT((s - 1) & ~RCU_SEQ_STATE_MASK, READ_ONCE(*sp));
+}
+
+/*
+ * Given a snapshot from rcu_seq_snap(), determine whether or not a
+ * full update-side operation has occurred.
+ */
+static inline bool rcu_seq_done(unsigned long *sp, unsigned long s)
+{
+	return ULONG_CMP_GE(READ_ONCE(*sp), s);
+}
+
+/*
+ * Has a grace period completed since the time the old gp_seq was collected?
+ */
+static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new)
+{
+	return ULONG_CMP_LT(old, new & ~RCU_SEQ_STATE_MASK);
+}
+
+/*
+ * Has a grace period started since the time the old gp_seq was collected?
+ */
+static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new)
+{
+	return ULONG_CMP_LT((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK,
+			    new);
+}
+
+/*
+ * Roughly how many full grace periods have elapsed between the collection
+ * of the two specified grace periods?
+ */
+static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old)
+{
+	unsigned long rnd_diff;
+
+	if (old == new)
+		return 0;
+	/*
+	 * Compute the number of grace periods (still shifted up), plus
+	 * one if either of new and old is not an exact grace period.
+	 */
+	rnd_diff = (new & ~RCU_SEQ_STATE_MASK) -
+		   ((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK) +
+		   ((new & RCU_SEQ_STATE_MASK) || (old & RCU_SEQ_STATE_MASK));
+	if (ULONG_CMP_GE(RCU_SEQ_STATE_MASK, rnd_diff))
+		return 1; /* Definitely no grace period has elapsed. */
+	return ((rnd_diff - RCU_SEQ_STATE_MASK - 1) >> RCU_SEQ_CTR_SHIFT) + 2;
+}
+
+/*
+ * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally
+ * by call_rcu() and rcu callback execution, and are therefore not part
+ * of the RCU API. These are in rcupdate.h because they are used by all
+ * RCU implementations.
+ */
+
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+# define STATE_RCU_HEAD_READY	0
+# define STATE_RCU_HEAD_QUEUED	1
+
+extern const struct debug_obj_descr rcuhead_debug_descr;
+
+static inline int debug_rcu_head_queue(struct rcu_head *head)
+{
+	int r1;
+
+	r1 = debug_object_activate(head, &rcuhead_debug_descr);
+	debug_object_active_state(head, &rcuhead_debug_descr,
+				  STATE_RCU_HEAD_READY,
+				  STATE_RCU_HEAD_QUEUED);
+	return r1;
+}
+
+static inline void debug_rcu_head_unqueue(struct rcu_head *head)
+{
+	debug_object_active_state(head, &rcuhead_debug_descr,
+				  STATE_RCU_HEAD_QUEUED,
+				  STATE_RCU_HEAD_READY);
+	debug_object_deactivate(head, &rcuhead_debug_descr);
+}
+#else	/* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+static inline int debug_rcu_head_queue(struct rcu_head *head)
+{
+	return 0;
+}
+
+static inline void debug_rcu_head_unqueue(struct rcu_head *head)
+{
+}
+#endif	/* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+
+extern int rcu_cpu_stall_suppress_at_boot;
+
+static inline bool rcu_stall_is_suppressed_at_boot(void)
+{
+	return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended();
+}
+
+#ifdef CONFIG_RCU_STALL_COMMON
+
+extern int rcu_cpu_stall_ftrace_dump;
+extern int rcu_cpu_stall_suppress;
+extern int rcu_cpu_stall_timeout;
+int rcu_jiffies_till_stall_check(void);
+
+static inline bool rcu_stall_is_suppressed(void)
+{
+	return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress;
+}
+
+#define rcu_ftrace_dump_stall_suppress() \
+do { \
+	if (!rcu_cpu_stall_suppress) \
+		rcu_cpu_stall_suppress = 3; \
+} while (0)
+
+#define rcu_ftrace_dump_stall_unsuppress() \
+do { \
+	if (rcu_cpu_stall_suppress == 3) \
+		rcu_cpu_stall_suppress = 0; \
+} while (0)
+
+#else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */
+
+static inline bool rcu_stall_is_suppressed(void)
+{
+	return rcu_stall_is_suppressed_at_boot();
+}
+#define rcu_ftrace_dump_stall_suppress()
+#define rcu_ftrace_dump_stall_unsuppress()
+#endif /* #ifdef CONFIG_RCU_STALL_COMMON */
+
+/*
+ * Strings used in tracepoints need to be exported via the
+ * tracing system such that tools like perf and trace-cmd can
+ * translate the string address pointers to actual text.
+ */
+#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)) { \
+		tracing_off(); \
+		rcu_ftrace_dump_stall_suppress(); \
+		ftrace_dump(oops_dump_mode); \
+		rcu_ftrace_dump_stall_unsuppress(); \
+	} \
+} while (0)
+
+void rcu_early_boot_tests(void);
+void rcu_test_sync_prims(void);
+
+/*
+ * This function really isn't for public consumption, but RCU is special in
+ * that context switches can allow the state machine to make progress.
+ */
+extern void resched_cpu(int cpu);
+
+#if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU)
+
+#include <linux/rcu_node_tree.h>
+
+extern int rcu_num_lvls;
+extern int num_rcu_lvl[];
+extern int rcu_num_nodes;
+static bool rcu_fanout_exact;
+static int rcu_fanout_leaf;
+
+/*
+ * Compute the per-level fanout, either using the exact fanout specified
+ * or balancing the tree, depending on the rcu_fanout_exact boot parameter.
+ */
+static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
+{
+	int i;
+
+	for (i = 0; i < RCU_NUM_LVLS; i++)
+		levelspread[i] = INT_MIN;
+	if (rcu_fanout_exact) {
+		levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
+		for (i = rcu_num_lvls - 2; i >= 0; i--)
+			levelspread[i] = RCU_FANOUT;
+	} else {
+		int ccur;
+		int cprv;
+
+		cprv = nr_cpu_ids;
+		for (i = rcu_num_lvls - 1; i >= 0; i--) {
+			ccur = levelcnt[i];
+			levelspread[i] = (cprv + ccur - 1) / ccur;
+			cprv = ccur;
+		}
+	}
+}
+
+extern void rcu_init_geometry(void);
+
+/* Returns a pointer to the first leaf rcu_node structure. */
+#define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1])
+
+/* Is this rcu_node a leaf? */
+#define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1)
+
+/* Is this rcu_node the last leaf? */
+#define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1])
+
+/*
+ * Do a full breadth-first scan of the {s,}rcu_node structures for the
+ * specified state structure (for SRCU) or the only rcu_state structure
+ * (for RCU).
+ */
+#define srcu_for_each_node_breadth_first(sp, rnp) \
+	for ((rnp) = &(sp)->node[0]; \
+	     (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++)
+#define rcu_for_each_node_breadth_first(rnp) \
+	srcu_for_each_node_breadth_first(&rcu_state, rnp)
+
+/*
+ * Scan the leaves of the rcu_node hierarchy for the rcu_state structure.
+ * Note that if there is a singleton rcu_node tree with but one rcu_node
+ * structure, this loop -will- visit the rcu_node structure.  It is still
+ * a leaf node, even if it is also the root node.
+ */
+#define rcu_for_each_leaf_node(rnp) \
+	for ((rnp) = rcu_first_leaf_node(); \
+	     (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++)
+
+/*
+ * Iterate over all possible CPUs in a leaf RCU node.
+ */
+#define for_each_leaf_node_possible_cpu(rnp, cpu) \
+	for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
+	     (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \
+	     (cpu) <= rnp->grphi; \
+	     (cpu) = cpumask_next((cpu), cpu_possible_mask))
+
+/*
+ * Iterate over all CPUs in a leaf RCU node's specified mask.
+ */
+#define rcu_find_next_bit(rnp, cpu, mask) \
+	((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu)))
+#define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \
+	for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
+	     (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \
+	     (cpu) <= rnp->grphi; \
+	     (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (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;							\
+})
+
+#define raw_lockdep_assert_held_rcu_node(p)				\
+	lockdep_assert_held(&ACCESS_PRIVATE(p, lock))
+
+#endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */
+
+#ifdef CONFIG_SRCU
+void srcu_init(void);
+#else /* #ifdef CONFIG_SRCU */
+static inline void srcu_init(void) { }
+#endif /* #else #ifdef CONFIG_SRCU */
+
+#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) { return true; }
+static inline bool rcu_gp_is_expedited(void) { return false; }
+static inline void rcu_expedite_gp(void) { }
+static inline void rcu_unexpedite_gp(void) { }
+static inline void rcu_request_urgent_qs_task(struct task_struct *t) { }
+#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);
+void show_rcu_tasks_gp_kthreads(void);
+void rcu_request_urgent_qs_task(struct task_struct *t);
+#endif /* #else #ifdef CONFIG_TINY_RCU */
+
+#define RCU_SCHEDULER_INACTIVE	0
+#define RCU_SCHEDULER_INIT	1
+#define RCU_SCHEDULER_RUNNING	2
+
+enum rcutorture_type {
+	RCU_FLAVOR,
+	RCU_TASKS_FLAVOR,
+	RCU_TASKS_RUDE_FLAVOR,
+	RCU_TASKS_TRACING_FLAVOR,
+	RCU_TRIVIAL_FLAVOR,
+	SRCU_FLAVOR,
+	INVALID_RCU_FLAVOR
+};
+
+#if defined(CONFIG_TREE_RCU)
+void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
+			    unsigned long *gp_seq);
+void do_trace_rcu_torture_read(const char *rcutorturename,
+			       struct rcu_head *rhp,
+			       unsigned long secs,
+			       unsigned long c_old,
+			       unsigned long c);
+void rcu_gp_set_torture_wait(int duration);
+#else
+static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
+					  int *flags, unsigned long *gp_seq)
+{
+	*flags = 0;
+	*gp_seq = 0;
+}
+#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
+static inline void rcu_gp_set_torture_wait(int duration) { }
+#endif
+
+#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
+long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
+#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 *gp_seq)
+{
+	if (test_type != SRCU_FLAVOR)
+		return;
+	*flags = 0;
+	*gp_seq = sp->srcu_idx;
+}
+
+#elif defined(CONFIG_TREE_SRCU)
+
+void srcutorture_get_gp_data(enum rcutorture_type test_type,
+			     struct srcu_struct *sp, int *flags,
+			     unsigned long *gp_seq);
+
+#endif
+
+#ifdef CONFIG_TINY_RCU
+static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; }
+static inline unsigned long rcu_get_gp_seq(void) { return 0; }
+static inline unsigned long rcu_exp_batches_completed(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 show_rcu_gp_kthreads(void) { }
+static inline int rcu_get_gp_kthreads_prio(void) { return 0; }
+static inline void rcu_fwd_progress_check(unsigned long j) { }
+#else /* #ifdef CONFIG_TINY_RCU */
+bool rcu_dynticks_zero_in_eqs(int cpu, int *vp);
+unsigned long rcu_get_gp_seq(void);
+unsigned long rcu_exp_batches_completed(void);
+unsigned long srcu_batches_completed(struct srcu_struct *sp);
+void show_rcu_gp_kthreads(void);
+int rcu_get_gp_kthreads_prio(void);
+void rcu_fwd_progress_check(unsigned long j);
+void rcu_force_quiescent_state(void);
+extern struct workqueue_struct *rcu_gp_wq;
+extern struct workqueue_struct *rcu_par_gp_wq;
+#endif /* #else #ifdef CONFIG_TINY_RCU */
+
+#ifdef CONFIG_RCU_NOCB_CPU
+bool rcu_is_nocb_cpu(int cpu);
+void rcu_bind_current_to_nocb(void);
+#else
+static inline bool rcu_is_nocb_cpu(int cpu) { return false; }
+static inline void rcu_bind_current_to_nocb(void) { }
+#endif
+
+#endif /* __LINUX_RCU_H */