From 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Mon, 13 May 2024 10:30:14 +0000 Subject: [PATCH] modify sin led gpio --- kernel/kernel/locking/rwsem.h | 87 ------------------------------------------- 1 files changed, 0 insertions(+), 87 deletions(-) diff --git a/kernel/kernel/locking/rwsem.h b/kernel/kernel/locking/rwsem.h index b9d0e72..e69de29 100644 --- a/kernel/kernel/locking/rwsem.h +++ b/kernel/kernel/locking/rwsem.h @@ -1,87 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * The owner field of the rw_semaphore structure will be set to - * RWSEM_READER_OWNED when a reader grabs the lock. A writer will clear - * the owner field when it unlocks. A reader, on the other hand, will - * not touch the owner field when it unlocks. - * - * In essence, the owner field now has the following 4 states: - * 1) 0 - * - lock is free or the owner hasn't set the field yet - * 2) RWSEM_READER_OWNED - * - lock is currently or previously owned by readers (lock is free - * or not set by owner yet) - * 3) RWSEM_ANONYMOUSLY_OWNED bit set with some other bits set as well - * - lock is owned by an anonymous writer, so spinning on the lock - * owner should be disabled. - * 4) Other non-zero value - * - a writer owns the lock and other writers can spin on the lock owner. - */ -#define RWSEM_ANONYMOUSLY_OWNED (1UL << 0) -#define RWSEM_READER_OWNED ((struct task_struct *)RWSEM_ANONYMOUSLY_OWNED) - -#ifdef CONFIG_DEBUG_RWSEMS -# define DEBUG_RWSEMS_WARN_ON(c) DEBUG_LOCKS_WARN_ON(c) -#else -# define DEBUG_RWSEMS_WARN_ON(c) -#endif - -#ifdef CONFIG_RWSEM_SPIN_ON_OWNER -/* - * All writes to owner are protected by WRITE_ONCE() to make sure that - * store tearing can't happen as optimistic spinners may read and use - * the owner value concurrently without lock. Read from owner, however, - * may not need READ_ONCE() as long as the pointer value is only used - * for comparison and isn't being dereferenced. - */ -static inline void rwsem_set_owner(struct rw_semaphore *sem) -{ - WRITE_ONCE(sem->owner, current); -} - -static inline void rwsem_clear_owner(struct rw_semaphore *sem) -{ - WRITE_ONCE(sem->owner, NULL); -} - -static inline void rwsem_set_reader_owned(struct rw_semaphore *sem) -{ - /* - * We check the owner value first to make sure that we will only - * do a write to the rwsem cacheline when it is really necessary - * to minimize cacheline contention. - */ - if (READ_ONCE(sem->owner) != RWSEM_READER_OWNED) - WRITE_ONCE(sem->owner, RWSEM_READER_OWNED); -} - -/* - * Return true if the a rwsem waiter can spin on the rwsem's owner - * and steal the lock, i.e. the lock is not anonymously owned. - * N.B. !owner is considered spinnable. - */ -static inline bool is_rwsem_owner_spinnable(struct task_struct *owner) -{ - return !((unsigned long)owner & RWSEM_ANONYMOUSLY_OWNED); -} - -/* - * Return true if rwsem is owned by an anonymous writer or readers. - */ -static inline bool rwsem_has_anonymous_owner(struct task_struct *owner) -{ - return (unsigned long)owner & RWSEM_ANONYMOUSLY_OWNED; -} -#else -static inline void rwsem_set_owner(struct rw_semaphore *sem) -{ -} - -static inline void rwsem_clear_owner(struct rw_semaphore *sem) -{ -} - -static inline void rwsem_set_reader_owned(struct rw_semaphore *sem) -{ -} -#endif -- Gitblit v1.6.2