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-rw-r--r--backport-include/linux/atomic.h54
1 files changed, 54 insertions, 0 deletions
diff --git a/backport-include/linux/atomic.h b/backport-include/linux/atomic.h
new file mode 100644
index 0000000..b4dd2e1
--- /dev/null
+++ b/backport-include/linux/atomic.h
@@ -0,0 +1,54 @@
+#ifndef __BP_ATOMIC_H
+#define __BP_ATOMIC_H
+#include_next <linux/atomic.h>
+
+/* atomic_cmpxchg_relaxed */
+#ifndef atomic_cmpxchg_relaxed
+#define atomic_cmpxchg_relaxed atomic_cmpxchg
+#define atomic_cmpxchg_acquire atomic_cmpxchg
+#define atomic_cmpxchg_release atomic_cmpxchg
+
+#else /* atomic_cmpxchg_relaxed */
+
+#ifndef atomic_cmpxchg_acquire
+#define atomic_cmpxchg_acquire(...) \
+ __atomic_op_acquire(atomic_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef atomic_cmpxchg_release
+#define atomic_cmpxchg_release(...) \
+ __atomic_op_release(atomic_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef atomic_cmpxchg
+#define atomic_cmpxchg(...) \
+ __atomic_op_fence(atomic_cmpxchg, __VA_ARGS__)
+#endif
+#endif /* atomic_cmpxchg_relaxed */
+
+/* these were introduced together, so just a single check is enough */
+#ifndef atomic_try_cmpxchg_acquire
+#ifndef atomic_try_cmpxchg
+#define __atomic_try_cmpxchg(type, _p, _po, _n) \
+({ \
+ typeof(_po) __po = (_po); \
+ typeof(*(_po)) __r, __o = *__po; \
+ __r = atomic_cmpxchg##type((_p), __o, (_n)); \
+ if (unlikely(__r != __o)) \
+ *__po = __r; \
+ likely(__r == __o); \
+})
+
+#define atomic_try_cmpxchg(_p, _po, _n) __atomic_try_cmpxchg(, _p, _po, _n)
+#define atomic_try_cmpxchg_relaxed(_p, _po, _n) __atomic_try_cmpxchg(_relaxed, _p, _po, _n)
+#define atomic_try_cmpxchg_acquire(_p, _po, _n) __atomic_try_cmpxchg(_acquire, _p, _po, _n)
+#define atomic_try_cmpxchg_release(_p, _po, _n) __atomic_try_cmpxchg(_release, _p, _po, _n)
+#else /* atomic_try_cmpxchg */
+#define atomic_try_cmpxchg_relaxed atomic_try_cmpxchg
+#define atomic_try_cmpxchg_acquire atomic_try_cmpxchg
+#define atomic_try_cmpxchg_release atomic_try_cmpxchg
+#endif /* atomic_try_cmpxchg */
+
+#endif /* atomic_try_cmpxchg_acquire */
+
+#endif /* __BP_ATOMIC_H */