diff options
| -rw-r--r-- | include/linux/srcu.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/include/linux/srcu.h b/include/linux/srcu.h index d4b12443b2ef..1eb520cd1680 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -181,4 +181,47 @@ static inline void srcu_read_unlock(struct srcu_struct *sp, int idx) __srcu_read_unlock(sp, idx); } +/** + * srcu_read_lock_raw - register a new reader for an SRCU-protected structure. + * @sp: srcu_struct in which to register the new reader. + * + * Enter an SRCU read-side critical section. Similar to srcu_read_lock(), + * but avoids the RCU-lockdep checking. This means that it is legal to + * use srcu_read_lock_raw() in one context, for example, in an exception + * handler, and then have the matching srcu_read_unlock_raw() in another + * context, for example in the task that took the exception. + * + * However, the entire SRCU read-side critical section must reside within a + * single task. For example, beware of using srcu_read_lock_raw() in + * a device interrupt handler and srcu_read_unlock() in the interrupted + * task: This will not work if interrupts are threaded. + */ +static inline int srcu_read_lock_raw(struct srcu_struct *sp) +{ + unsigned long flags; + int ret; + + local_irq_save(flags); + ret = __srcu_read_lock(sp); + local_irq_restore(flags); + return ret; +} + +/** + * srcu_read_unlock_raw - unregister reader from an SRCU-protected structure. + * @sp: srcu_struct in which to unregister the old reader. + * @idx: return value from corresponding srcu_read_lock_raw(). + * + * Exit an SRCU read-side critical section without lockdep-RCU checking. + * See srcu_read_lock_raw() for more details. + */ +static inline void srcu_read_unlock_raw(struct srcu_struct *sp, int idx) +{ + unsigned long flags; + + local_irq_save(flags); + __srcu_read_unlock(sp, idx); + local_irq_restore(flags); +} + #endif |