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authorDavid S. Miller <davem@davemloft.net>2018-04-21 16:31:52 -0400
committerDavid S. Miller <davem@davemloft.net>2018-04-21 16:32:48 -0400
commite0ada51db907ed2db5d46ad7ff86a8b5df68e59b (patch)
tree858966cee69ad8a50e59c4e02dcbde6ba2916151 /lib/lockref.c
parent0638eb573cde5888c0886c7f35da604e5db209a6 (diff)
parent83beed7b2b26f232d782127792dd0cd4362fdc41 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts were simple overlapping changes in microchip driver. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib/lockref.c')
-rw-r--r--lib/lockref.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/lockref.c b/lib/lockref.c
index 47169ed7e964..3d468b53d4c9 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -81,6 +81,34 @@ int lockref_get_not_zero(struct lockref *lockref)
EXPORT_SYMBOL(lockref_get_not_zero);
/**
+ * lockref_put_not_zero - Decrements count unless count <= 1 before decrement
+ * @lockref: pointer to lockref structure
+ * Return: 1 if count updated successfully or 0 if count would become zero
+ */
+int lockref_put_not_zero(struct lockref *lockref)
+{
+ int retval;
+
+ CMPXCHG_LOOP(
+ new.count--;
+ if (old.count <= 1)
+ return 0;
+ ,
+ return 1;
+ );
+
+ spin_lock(&lockref->lock);
+ retval = 0;
+ if (lockref->count > 1) {
+ lockref->count--;
+ retval = 1;
+ }
+ spin_unlock(&lockref->lock);
+ return retval;
+}
+EXPORT_SYMBOL(lockref_put_not_zero);
+
+/**
* lockref_get_or_lock - Increments count unless the count is 0 or dead
* @lockref: pointer to lockref structure
* Return: 1 if count updated successfully or 0 if count was zero