lockref: use BLOATED_SPINLOCKS to avoid explicit config dependencies

[firefly-linux-kernel-4.4.55.git] / include / linux / lockref.h

diff --git a/include/linux/lockref.h b/include/linux/lockref.h
index f279ed9a91631cca7f236d20ef5a29d152332932..c8929c3832db26d00d80f96e524afbb0e75c4df1 100644 (file)
--- a/include/linux/lockref.h
+++ b/include/linux/lockref.h
@@ -15,10 +15,15 @@
  */
 
 #include <linux/spinlock.h>
+#include <generated/bounds.h>
+
+#define USE_CMPXCHG_LOCKREF \
+       (IS_ENABLED(CONFIG_ARCH_USE_CMPXCHG_LOCKREF) && \
+        IS_ENABLED(CONFIG_SMP) && !BLOATED_SPINLOCKS)
 
 struct lockref {
        union {
-#ifdef CONFIG_CMPXCHG_LOCKREF
+#if USE_CMPXCHG_LOCKREF
                aligned_u64 lock_count;
 #endif
                struct {
@@ -36,4 +41,10 @@ extern int lockref_put_or_lock(struct lockref *);
 extern void lockref_mark_dead(struct lockref *);
 extern int lockref_get_not_dead(struct lockref *);
 
+/* Must be called under spinlock for reliable results */
+static inline int __lockref_is_dead(const struct lockref *l)
+{
+       return ((int)l->count < 0);
+}
+
 #endif /* __LINUX_LOCKREF_H */