[RFC][PATCH 06/12] instrumentation: Wire up cmpxchg128()

From: Peter Zijlstra
Date: Mon Dec 19 2022 - 10:46:30 EST


Wire up the cmpxchg128 familty in the atomic wrappery scripts.

These provide the generic cmpxchg128 family of functions from the
arch_ prefixed version, adding explicit instrumentation where needed.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/atomic/atomic-arch-fallback.h | 95 +++++++++++++++++++++++++++-
include/linux/atomic/atomic-instrumented.h | 77 ++++++++++++++++++++++
scripts/atomic/gen-atomic-fallback.sh | 4 -
scripts/atomic/gen-atomic-instrumented.sh | 4 -
4 files changed, 174 insertions(+), 6 deletions(-)

--- a/include/linux/atomic/atomic-arch-fallback.h
+++ b/include/linux/atomic/atomic-arch-fallback.h
@@ -77,6 +77,29 @@

#endif /* arch_cmpxchg64_relaxed */

+#ifndef arch_cmpxchg128_relaxed
+#define arch_cmpxchg128_acquire arch_cmpxchg128
+#define arch_cmpxchg128_release arch_cmpxchg128
+#define arch_cmpxchg128_relaxed arch_cmpxchg128
+#else /* arch_cmpxchg128_relaxed */
+
+#ifndef arch_cmpxchg128_acquire
+#define arch_cmpxchg128_acquire(...) \
+ __atomic_op_acquire(arch_cmpxchg128, __VA_ARGS__)
+#endif
+
+#ifndef arch_cmpxchg128_release
+#define arch_cmpxchg128_release(...) \
+ __atomic_op_release(arch_cmpxchg128, __VA_ARGS__)
+#endif
+
+#ifndef arch_cmpxchg128
+#define arch_cmpxchg128(...) \
+ __atomic_op_fence(arch_cmpxchg128, __VA_ARGS__)
+#endif
+
+#endif /* arch_cmpxchg128_relaxed */
+
#ifndef arch_try_cmpxchg_relaxed
#ifdef arch_try_cmpxchg
#define arch_try_cmpxchg_acquire arch_try_cmpxchg
@@ -217,6 +240,76 @@

#endif /* arch_try_cmpxchg64_relaxed */

+#ifndef arch_try_cmpxchg128_relaxed
+#ifdef arch_try_cmpxchg128
+#define arch_try_cmpxchg128_acquire arch_try_cmpxchg128
+#define arch_try_cmpxchg128_release arch_try_cmpxchg128
+#define arch_try_cmpxchg128_relaxed arch_try_cmpxchg128
+#endif /* arch_try_cmpxchg128 */
+
+#ifndef arch_try_cmpxchg128
+#define arch_try_cmpxchg128(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg128((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg128 */
+
+#ifndef arch_try_cmpxchg128_acquire
+#define arch_try_cmpxchg128_acquire(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg128_acquire((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg128_acquire */
+
+#ifndef arch_try_cmpxchg128_release
+#define arch_try_cmpxchg128_release(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg128_release((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg128_release */
+
+#ifndef arch_try_cmpxchg128_relaxed
+#define arch_try_cmpxchg128_relaxed(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg128_relaxed((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg128_relaxed */
+
+#else /* arch_try_cmpxchg128_relaxed */
+
+#ifndef arch_try_cmpxchg128_acquire
+#define arch_try_cmpxchg128_acquire(...) \
+ __atomic_op_acquire(arch_try_cmpxchg128, __VA_ARGS__)
+#endif
+
+#ifndef arch_try_cmpxchg128_release
+#define arch_try_cmpxchg128_release(...) \
+ __atomic_op_release(arch_try_cmpxchg128, __VA_ARGS__)
+#endif
+
+#ifndef arch_try_cmpxchg128
+#define arch_try_cmpxchg128(...) \
+ __atomic_op_fence(arch_try_cmpxchg128, __VA_ARGS__)
+#endif
+
+#endif /* arch_try_cmpxchg128_relaxed */
+
#ifndef arch_atomic_read_acquire
static __always_inline int
arch_atomic_read_acquire(const atomic_t *v)
@@ -2456,4 +2549,4 @@ arch_atomic64_dec_if_positive(atomic64_t
#endif

#endif /* _LINUX_ATOMIC_FALLBACK_H */
-// b5e87bdd5ede61470c29f7a7e4de781af3770f09
+// 46357a526de89c762d30fb238f35a7d5950a670b
--- a/include/linux/atomic/atomic-instrumented.h
+++ b/include/linux/atomic/atomic-instrumented.h
@@ -1968,6 +1968,36 @@ atomic_long_dec_if_positive(atomic_long_
arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__); \
})

+#define cmpxchg128(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ kcsan_mb(); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg128(__ai_ptr, __VA_ARGS__); \
+})
+
+#define cmpxchg128_acquire(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg128_acquire(__ai_ptr, __VA_ARGS__); \
+})
+
+#define cmpxchg128_release(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ kcsan_release(); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg128_release(__ai_ptr, __VA_ARGS__); \
+})
+
+#define cmpxchg128_relaxed(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg128_relaxed(__ai_ptr, __VA_ARGS__); \
+})
+
#define try_cmpxchg(ptr, oldp, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
@@ -2044,6 +2074,44 @@ atomic_long_dec_if_positive(atomic_long_
arch_try_cmpxchg64_relaxed(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})

+#define try_cmpxchg128(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ kcsan_mb(); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg128(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
+#define try_cmpxchg128_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_cmpxchg128_acquire(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
+#define try_cmpxchg128_release(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ kcsan_release(); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg128_release(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
+#define try_cmpxchg128_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_cmpxchg128_relaxed(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
#define cmpxchg_local(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
@@ -2058,6 +2126,13 @@ atomic_long_dec_if_positive(atomic_long_
arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__); \
})

+#define cmpxchg128_local(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg128_local(__ai_ptr, __VA_ARGS__); \
+})
+
#define sync_cmpxchg(ptr, ...) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
@@ -2083,4 +2158,4 @@ atomic_long_dec_if_positive(atomic_long_
})

#endif /* _LINUX_ATOMIC_INSTRUMENTED_H */
-// 764f741eb77a7ad565dc8d99ce2837d5542e8aee
+// 27320c1ec2bf2878ecb9df3ea4816a7bc0c57a52
--- a/scripts/atomic/gen-atomic-fallback.sh
+++ b/scripts/atomic/gen-atomic-fallback.sh
@@ -217,11 +217,11 @@ cat << EOF

EOF

-for xchg in "arch_xchg" "arch_cmpxchg" "arch_cmpxchg64"; do
+for xchg in "arch_xchg" "arch_cmpxchg" "arch_cmpxchg64" "arch_cmpxchg128"; do
gen_xchg_fallbacks "${xchg}"
done

-for cmpxchg in "cmpxchg" "cmpxchg64"; do
+for cmpxchg in "cmpxchg" "cmpxchg64" "cmpxchg128"; do
gen_try_cmpxchg_fallbacks "${cmpxchg}"
done

--- a/scripts/atomic/gen-atomic-instrumented.sh
+++ b/scripts/atomic/gen-atomic-instrumented.sh
@@ -166,14 +166,14 @@ grep '^[a-z]' "$1" | while read name met
done


-for xchg in "xchg" "cmpxchg" "cmpxchg64" "try_cmpxchg" "try_cmpxchg64"; do
+for xchg in "xchg" "cmpxchg" "cmpxchg64" "cmpxchg128" "try_cmpxchg" "try_cmpxchg64" "try_cmpxchg128"; do
for order in "" "_acquire" "_release" "_relaxed"; do
gen_xchg "${xchg}" "${order}" ""
printf "\n"
done
done

-for xchg in "cmpxchg_local" "cmpxchg64_local" "sync_cmpxchg"; do
+for xchg in "cmpxchg_local" "cmpxchg64_local" "cmpxchg128_local" "sync_cmpxchg"; do
gen_xchg "${xchg}" "" ""
printf "\n"
done