Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:
 "Here are the locking changes in this cycle:

   - rwsem unification and simpler micro-optimizations to prepare for
     more intrusive (and more lucrative) scalability improvements in
     v5.3 (Waiman Long)

   - Lockdep irq state tracking flag usage cleanups (Frederic
     Weisbecker)

   - static key improvements (Jakub Kicinski, Peter Zijlstra)

   - misc updates, cleanups and smaller fixes"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
  locking/lockdep: Remove unnecessary unlikely()
  locking/static_key: Don't take sleeping locks in __static_key_slow_dec_deferred()
  locking/static_key: Factor out the fast path of static_key_slow_dec()
  locking/static_key: Add support for deferred static branches
  locking/lockdep: Test all incompatible scenarios at once in check_irq_usage()
  locking/lockdep: Avoid bogus Clang warning
  locking/lockdep: Generate LOCKF_ bit composites
  locking/lockdep: Use expanded masks on find_usage_*() functions
  locking/lockdep: Map remaining magic numbers to lock usage mask names
  locking/lockdep: Move valid_state() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING
  locking/rwsem: Prevent unneeded warning during locking selftest
  locking/rwsem: Optimize rwsem structure for uncontended lock acquisition
  locking/rwsem: Enable lock event counting
  locking/lock_events: Don't show pvqspinlock events on bare metal
  locking/lock_events: Make lock_events available for all archs & other locks
  locking/qspinlock_stat: Introduce generic lockevent_*() counting APIs
  locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro
  locking/rwsem: Add debug check for __down_read*()
  locking/rwsem: Micro-optimize rwsem_try_read_lock_unqueued()
  locking/rwsem: Move rwsem internal function declarations to rwsem-xadd.h
  ...

4 files changed, 78 insertions, 72 deletions

diff --git a/include/linux/jump_label_ratelimit.h b/include/linux/jump_label_ratelimit.h
index a49f2b45b3f0..42710d5949ba 100644
--- a/include/linux/jump_label_ratelimit.h
+++ b/include/linux/jump_label_ratelimit.h
@@ -12,21 +12,79 @@ struct static_key_deferred {
 	struct delayed_work work;
 };
 
-extern void static_key_slow_dec_deferred(struct static_key_deferred *key);
-extern void static_key_deferred_flush(struct static_key_deferred *key);
+struct static_key_true_deferred {
+	struct static_key_true key;
+	unsigned long timeout;
+	struct delayed_work work;
+};
+
+struct static_key_false_deferred {
+	struct static_key_false key;
+	unsigned long timeout;
+	struct delayed_work work;
+};
+
+#define static_key_slow_dec_deferred(x)					\
+	__static_key_slow_dec_deferred(&(x)->key, &(x)->work, (x)->timeout)
+#define static_branch_slow_dec_deferred(x)				\
+	__static_key_slow_dec_deferred(&(x)->key.key, &(x)->work, (x)->timeout)
+
+#define static_key_deferred_flush(x)					\
+	__static_key_deferred_flush((x), &(x)->work)
+
+extern void
+__static_key_slow_dec_deferred(struct static_key *key,
+			       struct delayed_work *work,
+			       unsigned long timeout);
+extern void __static_key_deferred_flush(void *key, struct delayed_work *work);
 extern void
 jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl);
 
+extern void jump_label_update_timeout(struct work_struct *work);
+
+#define DEFINE_STATIC_KEY_DEFERRED_TRUE(name, rl)			\
+	struct static_key_true_deferred name = {			\
+		.key =		{ STATIC_KEY_INIT_TRUE },		\
+		.timeout =	(rl),					\
+		.work =	__DELAYED_WORK_INITIALIZER((name).work,		\
+						   jump_label_update_timeout, \
+						   0),			\
+	}
+
+#define DEFINE_STATIC_KEY_DEFERRED_FALSE(name, rl)			\
+	struct static_key_false_deferred name = {			\
+		.key =		{ STATIC_KEY_INIT_FALSE },		\
+		.timeout =	(rl),					\
+		.work =	__DELAYED_WORK_INITIALIZER((name).work,		\
+						   jump_label_update_timeout, \
+						   0),			\
+	}
+
+#define static_branch_deferred_inc(x)	static_branch_inc(&(x)->key)
+
 #else	/* !CONFIG_JUMP_LABEL */
 struct static_key_deferred {
 	struct static_key  key;
 };
+struct static_key_true_deferred {
+	struct static_key_true key;
+};
+struct static_key_false_deferred {
+	struct static_key_false key;
+};
+#define DEFINE_STATIC_KEY_DEFERRED_TRUE(name, rl)	\
+	struct static_key_true_deferred name = { STATIC_KEY_TRUE_INIT }
+#define DEFINE_STATIC_KEY_DEFERRED_FALSE(name, rl)	\
+	struct static_key_false_deferred name = { STATIC_KEY_FALSE_INIT }
+
+#define static_branch_slow_dec_deferred(x)	static_branch_dec(&(x)->key)
+
 static inline void static_key_slow_dec_deferred(struct static_key_deferred *key)
 {
 	STATIC_KEY_CHECK_USE(key);
 	static_key_slow_dec(&key->key);
 }
-static inline void static_key_deferred_flush(struct static_key_deferred *key)
+static inline void static_key_deferred_flush(void *key)
 {
 	STATIC_KEY_CHECK_USE(key);
 }
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 6f165d625320..6e2377e6c1d6 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -476,7 +476,7 @@ struct pin_cookie { };
 
 #define NIL_COOKIE (struct pin_cookie){ }
 
-#define lockdep_pin_lock(l)			({ struct pin_cookie cookie; cookie; })
+#define lockdep_pin_lock(l)			({ struct pin_cookie cookie = { }; cookie; })
 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
 
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h
deleted file mode 100644
index e47568363e5e..000000000000
--- a/include/linux/rwsem-spinlock.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/* rwsem-spinlock.h: fallback C implementation
- *
- * Copyright (c) 2001   David Howells (dhowells@redhat.com).
- * - Derived partially from ideas by Andrea Arcangeli <andrea@suse.de>
- * - Derived also from comments by Linus
- */
-
-#ifndef _LINUX_RWSEM_SPINLOCK_H
-#define _LINUX_RWSEM_SPINLOCK_H
-
-#ifndef _LINUX_RWSEM_H
-#error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead"
-#endif
-
-#ifdef __KERNEL__
-/*
- * the rw-semaphore definition
- * - if count is 0 then there are no active readers or writers
- * - if count is +ve then that is the number of active readers
- * - if count is -1 then there is one active writer
- * - if wait_list is not empty, then there are processes waiting for the semaphore
- */
-struct rw_semaphore {
-	__s32			count;
-	raw_spinlock_t		wait_lock;
-	struct list_head	wait_list;
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	struct lockdep_map dep_map;
-#endif
-};
-
-#define RWSEM_UNLOCKED_VALUE		0x00000000
-
-extern void __down_read(struct rw_semaphore *sem);
-extern int __must_check __down_read_killable(struct rw_semaphore *sem);
-extern int __down_read_trylock(struct rw_semaphore *sem);
-extern void __down_write(struct rw_semaphore *sem);
-extern int __must_check __down_write_killable(struct rw_semaphore *sem);
-extern int __down_write_trylock(struct rw_semaphore *sem);
-extern void __up_read(struct rw_semaphore *sem);
-extern void __up_write(struct rw_semaphore *sem);
-extern void __downgrade_write(struct rw_semaphore *sem);
-extern int rwsem_is_locked(struct rw_semaphore *sem);
-
-#endif /* __KERNEL__ */
-#endif /* _LINUX_RWSEM_SPINLOCK_H */
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 67dbb57508b1..2ea18a3def04 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -20,25 +20,30 @@
 #include <linux/osq_lock.h>
 #endif
 
-struct rw_semaphore;
-
-#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
-#include <linux/rwsem-spinlock.h> /* use a generic implementation */
-#define __RWSEM_INIT_COUNT(name)	.count = RWSEM_UNLOCKED_VALUE
-#else
-/* All arch specific implementations share the same struct */
+/*
+ * For an uncontended rwsem, count and owner are the only fields a task
+ * needs to touch when acquiring the rwsem. So they are put next to each
+ * other to increase the chance that they will share the same cacheline.
+ *
+ * In a contended rwsem, the owner is likely the most frequently accessed
+ * field in the structure as the optimistic waiter that holds the osq lock
+ * will spin on owner. For an embedded rwsem, other hot fields in the
+ * containing structure should be moved further away from the rwsem to
+ * reduce the chance that they will share the same cacheline causing
+ * cacheline bouncing problem.
+ */
 struct rw_semaphore {
 	atomic_long_t count;
-	struct list_head wait_list;
-	raw_spinlock_t wait_lock;
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
-	struct optimistic_spin_queue osq; /* spinner MCS lock */
 	/*
 	 * Write owner. Used as a speculative check to see
 	 * if the owner is running on the cpu.
 	 */
 	struct task_struct *owner;
+	struct optimistic_spin_queue osq; /* spinner MCS lock */
 #endif
+	raw_spinlock_t wait_lock;
+	struct list_head wait_list;
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	struct lockdep_map	dep_map;
 #endif
@@ -50,24 +55,14 @@ struct rw_semaphore {
  */
 #define RWSEM_OWNER_UNKNOWN	((struct task_struct *)-2L)
 
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_read_failed_killable(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed_killable(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
-
-/* Include the arch specific part */
-#include <asm/rwsem.h>
-
 /* In all implementations count != 0 means locked */
 static inline int rwsem_is_locked(struct rw_semaphore *sem)
 {
 	return atomic_long_read(&sem->count) != 0;
 }
 
+#define RWSEM_UNLOCKED_VALUE		0L
 #define __RWSEM_INIT_COUNT(name)	.count = ATOMIC_LONG_INIT(RWSEM_UNLOCKED_VALUE)
-#endif
 
 /* Common initializer macros and functions */