diff options
Diffstat (limited to 'include/linux/seqlock.h')
| -rw-r--r-- | include/linux/seqlock.h | 36 |
1 files changed, 15 insertions, 21 deletions
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 88b917d4ebde..f2a7a467e998 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -620,7 +620,7 @@ static inline void seqcount_latch_init(seqcount_latch_t *s) /** * raw_read_seqcount_latch() - pick even/odd latch data copy - * @s: Pointer to seqcount_t, seqcount_raw_spinlock_t, or seqcount_latch_t + * @s: Pointer to seqcount_latch_t * * See raw_write_seqcount_latch() for details and a full reader/writer * usage example. @@ -629,17 +629,14 @@ static inline void seqcount_latch_init(seqcount_latch_t *s) * picking which data copy to read. The full counter must then be checked * with read_seqcount_latch_retry(). */ -#define raw_read_seqcount_latch(s) \ -({ \ - /* \ - * Pairs with the first smp_wmb() in raw_write_seqcount_latch(). \ - * Due to the dependent load, a full smp_rmb() is not needed. \ - */ \ - _Generic(*(s), \ - seqcount_t: READ_ONCE(((seqcount_t *)s)->sequence), \ - seqcount_raw_spinlock_t: READ_ONCE(((seqcount_raw_spinlock_t *)s)->seqcount.sequence), \ - seqcount_latch_t: READ_ONCE(((seqcount_latch_t *)s)->seqcount.sequence)); \ -}) +static inline unsigned raw_read_seqcount_latch(const seqcount_latch_t *s) +{ + /* + * Pairs with the first smp_wmb() in raw_write_seqcount_latch(). + * Due to the dependent load, a full smp_rmb() is not needed. + */ + return READ_ONCE(s->seqcount.sequence); +} /** * read_seqcount_latch_retry() - end a seqcount_latch_t read section @@ -656,7 +653,7 @@ read_seqcount_latch_retry(const seqcount_latch_t *s, unsigned start) /** * raw_write_seqcount_latch() - redirect latch readers to even/odd copy - * @s: Pointer to seqcount_t, seqcount_raw_spinlock_t, or seqcount_latch_t + * @s: Pointer to seqcount_latch_t * * The latch technique is a multiversion concurrency control method that allows * queries during non-atomic modifications. If you can guarantee queries never @@ -735,14 +732,11 @@ read_seqcount_latch_retry(const seqcount_latch_t *s, unsigned start) * When data is a dynamic data structure; one should use regular RCU * patterns to manage the lifetimes of the objects within. */ -#define raw_write_seqcount_latch(s) \ -{ \ - smp_wmb(); /* prior stores before incrementing "sequence" */ \ - _Generic(*(s), \ - seqcount_t: ((seqcount_t *)s)->sequence++, \ - seqcount_raw_spinlock_t:((seqcount_raw_spinlock_t *)s)->seqcount.sequence++, \ - seqcount_latch_t: ((seqcount_latch_t *)s)->seqcount.sequence++); \ - smp_wmb(); /* increment "sequence" before following stores */ \ +static inline void raw_write_seqcount_latch(seqcount_latch_t *s) +{ + smp_wmb(); /* prior stores before incrementing "sequence" */ + s->seqcount.sequence++; + smp_wmb(); /* increment "sequence" before following stores */ } /* |