diff options
| -rw-r--r-- | include/linux/seqlock.h | 25 |
1 files changed, 5 insertions, 20 deletions
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index d90d8ee29d81..fffeb754880f 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -157,7 +157,7 @@ __seqprop_##lockname##_const_ptr(const seqcount_##lockname##_t *s) \ static __always_inline unsigned \ __seqprop_##lockname##_sequence(const seqcount_##lockname##_t *s) \ { \ - unsigned seq = READ_ONCE(s->seqcount.sequence); \ + unsigned seq = smp_load_acquire(&s->seqcount.sequence); \ \ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) \ return seq; \ @@ -170,7 +170,7 @@ __seqprop_##lockname##_sequence(const seqcount_##lockname##_t *s) \ * Re-read the sequence counter since the (possibly \ * preempted) writer made progress. \ */ \ - seq = READ_ONCE(s->seqcount.sequence); \ + seq = smp_load_acquire(&s->seqcount.sequence); \ } \ \ return seq; \ @@ -208,7 +208,7 @@ static inline const seqcount_t *__seqprop_const_ptr(const seqcount_t *s) static inline unsigned __seqprop_sequence(const seqcount_t *s) { - return READ_ONCE(s->sequence); + return smp_load_acquire(&s->sequence); } static inline bool __seqprop_preemptible(const seqcount_t *s) @@ -263,17 +263,9 @@ SEQCOUNT_LOCKNAME(mutex, struct mutex, true, mutex) #define seqprop_assert(s) __seqprop(s, assert)(s) /** - * __read_seqcount_begin() - begin a seqcount_t read section w/o barrier + * __read_seqcount_begin() - begin a seqcount_t read section * @s: Pointer to seqcount_t or any of the seqcount_LOCKNAME_t variants * - * __read_seqcount_begin is like read_seqcount_begin, but has no smp_rmb() - * barrier. Callers should ensure that smp_rmb() or equivalent ordering is - * provided before actually loading any of the variables that are to be - * protected in this critical section. - * - * Use carefully, only in critical code, and comment how the barrier is - * provided. - * * Return: count to be passed to read_seqcount_retry() */ #define __read_seqcount_begin(s) \ @@ -293,13 +285,7 @@ SEQCOUNT_LOCKNAME(mutex, struct mutex, true, mutex) * * Return: count to be passed to read_seqcount_retry() */ -#define raw_read_seqcount_begin(s) \ -({ \ - unsigned _seq = __read_seqcount_begin(s); \ - \ - smp_rmb(); \ - _seq; \ -}) +#define raw_read_seqcount_begin(s) __read_seqcount_begin(s) /** * read_seqcount_begin() - begin a seqcount_t read critical section @@ -328,7 +314,6 @@ SEQCOUNT_LOCKNAME(mutex, struct mutex, true, mutex) ({ \ unsigned __seq = seqprop_sequence(s); \ \ - smp_rmb(); \ kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); \ __seq; \ }) |