asm-generic/atomic: Add try_cmpxchg() fallbacks

Only x86 provides try_cmpxchg() outside of the atomic_t interfaces,
provide generic fallbacks to create this interface from the widely
available cmpxchg() function.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/159870621515.1229682.15506193091065001742.stgit@devnote2

3 files changed, 290 insertions, 106 deletions

diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index 379986e40159..2cab3fdaae3b 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -1642,148 +1642,192 @@ atomic64_dec_if_positive(atomic64_t *v)
 #endif
 
 #if !defined(arch_xchg_relaxed) || defined(arch_xchg)
-#define xchg(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_xchg(__ai_ptr, __VA_ARGS__);				\
+#define xchg(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_xchg(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_xchg_acquire)
-#define xchg_acquire(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_xchg_acquire(__ai_ptr, __VA_ARGS__);				\
+#define xchg_acquire(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_xchg_acquire(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_xchg_release)
-#define xchg_release(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_xchg_release(__ai_ptr, __VA_ARGS__);				\
+#define xchg_release(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_xchg_release(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_xchg_relaxed)
-#define xchg_relaxed(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_xchg_relaxed(__ai_ptr, __VA_ARGS__);				\
+#define xchg_relaxed(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_xchg_relaxed(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if !defined(arch_cmpxchg_relaxed) || defined(arch_cmpxchg)
-#define cmpxchg(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_cmpxchg_acquire)
-#define cmpxchg_acquire(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg_acquire(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg_acquire(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg_acquire(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_cmpxchg_release)
-#define cmpxchg_release(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg_release(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg_release(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg_release(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_cmpxchg_relaxed)
-#define cmpxchg_relaxed(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg_relaxed(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg_relaxed(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg_relaxed(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if !defined(arch_cmpxchg64_relaxed) || defined(arch_cmpxchg64)
-#define cmpxchg64(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg64(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg64(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg64(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_cmpxchg64_acquire)
-#define cmpxchg64_acquire(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg64_acquire(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg64_acquire(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg64_acquire(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_cmpxchg64_release)
-#define cmpxchg64_release(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg64_release(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg64_release(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg64_release(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
 #if defined(arch_cmpxchg64_relaxed)
-#define cmpxchg64_relaxed(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg64_relaxed(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__); \
 })
 #endif
 
-#define cmpxchg_local(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg_local(__ai_ptr, __VA_ARGS__);				\
+#if !defined(arch_try_cmpxchg_relaxed) || defined(arch_try_cmpxchg)
+#define try_cmpxchg(ptr, oldp, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	typeof(oldp) __ai_oldp = (oldp); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+	arch_try_cmpxchg(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#if defined(arch_try_cmpxchg_acquire)
+#define try_cmpxchg_acquire(ptr, oldp, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	typeof(oldp) __ai_oldp = (oldp); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+	arch_try_cmpxchg_acquire(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#if defined(arch_try_cmpxchg_release)
+#define try_cmpxchg_release(ptr, oldp, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	typeof(oldp) __ai_oldp = (oldp); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+	arch_try_cmpxchg_release(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#if defined(arch_try_cmpxchg_relaxed)
+#define try_cmpxchg_relaxed(ptr, oldp, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	typeof(oldp) __ai_oldp = (oldp); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+	arch_try_cmpxchg_relaxed(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#define cmpxchg_local(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg_local(__ai_ptr, __VA_ARGS__); \
 })
 
-#define cmpxchg64_local(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg64_local(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__); \
 })
 
-#define sync_cmpxchg(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr));		\
-	arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__);				\
+#define sync_cmpxchg(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+	arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__); \
 })
 
-#define cmpxchg_double(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr));		\
-	arch_cmpxchg_double(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg_double(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
+	arch_cmpxchg_double(__ai_ptr, __VA_ARGS__); \
 })
 
 
-#define cmpxchg_double_local(ptr, ...)						\
-({									\
-	typeof(ptr) __ai_ptr = (ptr);					\
-	instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr));		\
-	arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__);				\
+#define cmpxchg_double_local(ptr, ...) \
+({ \
+	typeof(ptr) __ai_ptr = (ptr); \
+	instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
+	arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \
 })
 
 #endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */
-// 89bf97f3a7509b740845e51ddf31055b48a81f40
+// ff0fe7f81ee97f01f13bb78b0e3ce800bc56d9dd
diff --git a/include/linux/atomic-arch-fallback.h b/include/linux/atomic-arch-fallback.h
index bcb6aa27cfa6..a3dba31df01e 100644
--- a/include/linux/atomic-arch-fallback.h
+++ b/include/linux/atomic-arch-fallback.h
@@ -9,9 +9,9 @@
 #include <linux/compiler.h>
 
 #ifndef arch_xchg_relaxed
-#define arch_xchg_relaxed		arch_xchg
-#define arch_xchg_acquire		arch_xchg
-#define arch_xchg_release		arch_xchg
+#define arch_xchg_acquire arch_xchg
+#define arch_xchg_release arch_xchg
+#define arch_xchg_relaxed arch_xchg
 #else /* arch_xchg_relaxed */
 
 #ifndef arch_xchg_acquire
@@ -32,9 +32,9 @@
 #endif /* arch_xchg_relaxed */
 
 #ifndef arch_cmpxchg_relaxed
-#define arch_cmpxchg_relaxed		arch_cmpxchg
-#define arch_cmpxchg_acquire		arch_cmpxchg
-#define arch_cmpxchg_release		arch_cmpxchg
+#define arch_cmpxchg_acquire arch_cmpxchg
+#define arch_cmpxchg_release arch_cmpxchg
+#define arch_cmpxchg_relaxed arch_cmpxchg
 #else /* arch_cmpxchg_relaxed */
 
 #ifndef arch_cmpxchg_acquire
@@ -55,9 +55,9 @@
 #endif /* arch_cmpxchg_relaxed */
 
 #ifndef arch_cmpxchg64_relaxed
-#define arch_cmpxchg64_relaxed		arch_cmpxchg64
-#define arch_cmpxchg64_acquire		arch_cmpxchg64
-#define arch_cmpxchg64_release		arch_cmpxchg64
+#define arch_cmpxchg64_acquire arch_cmpxchg64
+#define arch_cmpxchg64_release arch_cmpxchg64
+#define arch_cmpxchg64_relaxed arch_cmpxchg64
 #else /* arch_cmpxchg64_relaxed */
 
 #ifndef arch_cmpxchg64_acquire
@@ -77,6 +77,76 @@
 
 #endif /* arch_cmpxchg64_relaxed */
 
+#ifndef arch_try_cmpxchg_relaxed
+#ifdef arch_try_cmpxchg
+#define arch_try_cmpxchg_acquire arch_try_cmpxchg
+#define arch_try_cmpxchg_release arch_try_cmpxchg
+#define arch_try_cmpxchg_relaxed arch_try_cmpxchg
+#endif /* arch_try_cmpxchg */
+
+#ifndef arch_try_cmpxchg
+#define arch_try_cmpxchg(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = arch_cmpxchg((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg */
+
+#ifndef arch_try_cmpxchg_acquire
+#define arch_try_cmpxchg_acquire(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = arch_cmpxchg_acquire((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_acquire */
+
+#ifndef arch_try_cmpxchg_release
+#define arch_try_cmpxchg_release(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = arch_cmpxchg_release((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_release */
+
+#ifndef arch_try_cmpxchg_relaxed
+#define arch_try_cmpxchg_relaxed(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = arch_cmpxchg_relaxed((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_relaxed */
+
+#else /* arch_try_cmpxchg_relaxed */
+
+#ifndef arch_try_cmpxchg_acquire
+#define arch_try_cmpxchg_acquire(...) \
+	__atomic_op_acquire(arch_try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef arch_try_cmpxchg_release
+#define arch_try_cmpxchg_release(...) \
+	__atomic_op_release(arch_try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef arch_try_cmpxchg
+#define arch_try_cmpxchg(...) \
+	__atomic_op_fence(arch_try_cmpxchg, __VA_ARGS__)
+#endif
+
+#endif /* arch_try_cmpxchg_relaxed */
+
 #ifndef arch_atomic_read_acquire
 static __always_inline int
 arch_atomic_read_acquire(const atomic_t *v)
@@ -2288,4 +2358,4 @@ arch_atomic64_dec_if_positive(atomic64_t *v)
 #endif
 
 #endif /* _LINUX_ATOMIC_FALLBACK_H */
-// 90cd26cfd69d2250303d654955a0cc12620fb91b
+// cca554917d7ea73d5e3e7397dd70c484cad9b2c4
diff --git a/include/linux/atomic-fallback.h b/include/linux/atomic-fallback.h
index fd525c71d676..2a3f55d98be9 100644
--- a/include/linux/atomic-fallback.h
+++ b/include/linux/atomic-fallback.h
@@ -9,9 +9,9 @@
 #include <linux/compiler.h>
 
 #ifndef xchg_relaxed
-#define xchg_relaxed		xchg
-#define xchg_acquire		xchg
-#define xchg_release		xchg
+#define xchg_acquire xchg
+#define xchg_release xchg
+#define xchg_relaxed xchg
 #else /* xchg_relaxed */
 
 #ifndef xchg_acquire
@@ -32,9 +32,9 @@
 #endif /* xchg_relaxed */
 
 #ifndef cmpxchg_relaxed
-#define cmpxchg_relaxed		cmpxchg
-#define cmpxchg_acquire		cmpxchg
-#define cmpxchg_release		cmpxchg
+#define cmpxchg_acquire cmpxchg
+#define cmpxchg_release cmpxchg
+#define cmpxchg_relaxed cmpxchg
 #else /* cmpxchg_relaxed */
 
 #ifndef cmpxchg_acquire
@@ -55,9 +55,9 @@
 #endif /* cmpxchg_relaxed */
 
 #ifndef cmpxchg64_relaxed
-#define cmpxchg64_relaxed		cmpxchg64
-#define cmpxchg64_acquire		cmpxchg64
-#define cmpxchg64_release		cmpxchg64
+#define cmpxchg64_acquire cmpxchg64
+#define cmpxchg64_release cmpxchg64
+#define cmpxchg64_relaxed cmpxchg64
 #else /* cmpxchg64_relaxed */
 
 #ifndef cmpxchg64_acquire
@@ -77,6 +77,76 @@
 
 #endif /* cmpxchg64_relaxed */
 
+#ifndef try_cmpxchg_relaxed
+#ifdef try_cmpxchg
+#define try_cmpxchg_acquire try_cmpxchg
+#define try_cmpxchg_release try_cmpxchg
+#define try_cmpxchg_relaxed try_cmpxchg
+#endif /* try_cmpxchg */
+
+#ifndef try_cmpxchg
+#define try_cmpxchg(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = cmpxchg((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* try_cmpxchg */
+
+#ifndef try_cmpxchg_acquire
+#define try_cmpxchg_acquire(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = cmpxchg_acquire((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* try_cmpxchg_acquire */
+
+#ifndef try_cmpxchg_release
+#define try_cmpxchg_release(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = cmpxchg_release((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* try_cmpxchg_release */
+
+#ifndef try_cmpxchg_relaxed
+#define try_cmpxchg_relaxed(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = cmpxchg_relaxed((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* try_cmpxchg_relaxed */
+
+#else /* try_cmpxchg_relaxed */
+
+#ifndef try_cmpxchg_acquire
+#define try_cmpxchg_acquire(...) \
+	__atomic_op_acquire(try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef try_cmpxchg_release
+#define try_cmpxchg_release(...) \
+	__atomic_op_release(try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef try_cmpxchg
+#define try_cmpxchg(...) \
+	__atomic_op_fence(try_cmpxchg, __VA_ARGS__)
+#endif
+
+#endif /* try_cmpxchg_relaxed */
+
 #define arch_atomic_read atomic_read
 #define arch_atomic_read_acquire atomic_read_acquire
 
@@ -2522,4 +2592,4 @@ atomic64_dec_if_positive(atomic64_t *v)
 #endif
 
 #endif /* _LINUX_ATOMIC_FALLBACK_H */
-// 9d95b56f98d82a2a26c7b79ccdd0c47572d50a6f
+// d78e6c293c661c15188f0ec05bce45188c8d5892