compat_ioctl: pppoe: fix PPPOEIOCSFWD handling

[mirror_ubuntu-bionic-kernel.git] / include / linux / wait_bit.h

diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h
index 61b39eaf7cad50106f75f10782d1ae684a454f02..612b82ca68b5d09f1d50a9c1f618d420240d779d 100644 (file)
--- a/include/linux/wait_bit.h
+++ b/include/linux/wait_bit.h
@@ -262,4 +262,21 @@ int wait_on_atomic_t(atomic_t *val, wait_atomic_t_action_f action, unsigned mode
        return out_of_line_wait_on_atomic_t(val, action, mode);
 }
 
+/**
+ * clear_and_wake_up_bit - clear a bit and wake up anyone waiting on that bit
+ *
+ * @bit: the bit of the word being waited on
+ * @word: the word being waited on, a kernel virtual address
+ *
+ * You can use this helper if bitflags are manipulated atomically rather than
+ * non-atomically under a lock.
+ */
+static inline void clear_and_wake_up_bit(int bit, void *word)
+{
+       clear_bit_unlock(bit, word);
+       /* See wake_up_bit() for which memory barrier you need to use. */
+       smp_mb__after_atomic();
+       wake_up_bit(word, bit);
+}
+
 #endif /* _LINUX_WAIT_BIT_H */