aboutsummaryrefslogtreecommitdiffstats
path: root/lib/dec_and_lock.c
diff options
context:
space:
mode:
authorJonathan Corbet <corbet@lwn.net>2018-07-02 11:14:50 -0600
committerJonathan Corbet <corbet@lwn.net>2018-07-02 11:14:50 -0600
commit5f6654094ff35a7a92eb76667788ef633595e4ea (patch)
tree8404c5fb245cddbc6877b97a9bf53139c95da852 /lib/dec_and_lock.c
parent5105730fbf6789ff9e20837bdefe32e8ba133595 (diff)
parent021c91791a5e7e85c567452f1be3e4c2c6cb6063 (diff)
downloadkernel_replicant_linux-5f6654094ff35a7a92eb76667788ef633595e4ea.tar.gz
kernel_replicant_linux-5f6654094ff35a7a92eb76667788ef633595e4ea.tar.bz2
kernel_replicant_linux-5f6654094ff35a7a92eb76667788ef633595e4ea.zip
Merge tag 'v4.18-rc3' into docs-next
-rc1 broke the docs build due to changes in the e100/e1000 drivers; -rc3 got the fixes via the networking tree. Pull in -rc3 so that the docs tree can actually build the docs again.
Diffstat (limited to 'lib/dec_and_lock.c')
-rw-r--r--lib/dec_and_lock.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/dec_and_lock.c b/lib/dec_and_lock.c
index 347fa7ac2e8a..9555b68bb774 100644
--- a/lib/dec_and_lock.c
+++ b/lib/dec_and_lock.c
@@ -33,3 +33,19 @@ int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
}
EXPORT_SYMBOL(_atomic_dec_and_lock);
+
+int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock,
+ unsigned long *flags)
+{
+ /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+ if (atomic_add_unless(atomic, -1, 1))
+ return 0;
+
+ /* Otherwise do it the slow way */
+ spin_lock_irqsave(lock, *flags);
+ if (atomic_dec_and_test(atomic))
+ return 1;
+ spin_unlock_irqrestore(lock, *flags);
+ return 0;
+}
+EXPORT_SYMBOL(_atomic_dec_and_lock_irqsave);