/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __LINUX_LOCKREF_H #define __LINUX_LOCKREF_H /* * Locked reference counts. * * These are different from just plain atomic refcounts in that they * are atomic with respect to the spinlock that goes with them. In * particular, there can be implementations that don't actually get * the spinlock for the common decrement/increment operations, but they * still have to check that the operation is done semantically as if * the spinlock had been taken (using a cmpxchg operation that covers * both the lock and the count word, or using memory transactions, for * example). */ #include <linux/spinlock.h> #include <generated/bounds.h> #define USE_CMPXCHG_LOCKREF \ (IS_ENABLED(CONFIG_ARCH_USE_CMPXCHG_LOCKREF) && \ IS_ENABLED(CONFIG_SMP) && SPINLOCK_SIZE <= 4) struct lockref { union { #if USE_CMPXCHG_LOCKREF aligned_u64 lock_count; #endif struct { spinlock_t lock; int count; }; }; }; extern void lockref_get(struct lockref *); extern int lockref_put_return(struct lockref *); extern int lockref_get_not_zero(struct lockref *); extern int lockref_get_or_lock(struct lockref *); extern int lockref_put_or_lock(struct lockref *); extern void lockref_mark_dead(struct lockref *); extern int lockref_get_not_dead(struct lockref *); /* Must be called under spinlock for reliable results */
static inline int __lockref_is_dead(const struct lockref *l) { return ((int)l->count < 0); }Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Steven Whitehouse | 25 | 100.00% | 1 | 100.00% |
| Total | 25 | 100.00% | 1 | 100.00% |
| Person | Tokens | Prop | Commits | CommitProp |
| Linus Torvalds | 55 | 39.86% | 5 | 50.00% |
| Waiman Long | 45 | 32.61% | 1 | 10.00% |
| Steven Whitehouse | 26 | 18.84% | 1 | 10.00% |
| Peter Zijlstra | 10 | 7.25% | 1 | 10.00% |
| Greg Kroah-Hartman | 1 | 0.72% | 1 | 10.00% |
| Kirill A. Shutemov | 1 | 0.72% | 1 | 10.00% |
| Total | 138 | 100.00% | 10 | 100.00% |