linux-kernel - [tip: locking/core] locking/atomic: Add generic try_cmpxchg{,64}

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Date:   Sat, 29 Apr 2023 07:18:08 -0000
From:   "tip-bot2 for Uros Bizjak" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Uros Bizjak <ubizjak@...il.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Linus Torvalds <torvalds@...ux-foundation.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: locking/core] locking/atomic: Add generic
 try_cmpxchg{,64}_local() support

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     e6ce9d741163af0b846637ce6550ae8a671b1588
Gitweb:        https://git.kernel.org/tip/e6ce9d741163af0b846637ce6550ae8a671b1588
Author:        Uros Bizjak <ubizjak@...il.com>
AuthorDate:    Wed, 05 Apr 2023 16:17:06 +02:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Sat, 29 Apr 2023 09:09:02 +02:00

locking/atomic: Add generic try_cmpxchg{,64}_local() support

Add generic support for try_cmpxchg{,64}_local() and their falbacks.

These provides the generic try_cmpxchg_local family of functions
from the arch_ prefixed version, also adding explicit instrumentation.

Signed-off-by: Uros Bizjak <ubizjak@...il.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Acked-by: Mark Rutland <mark.rutland@....com>
Link: https://lore.kernel.org/r/20230405141710.3551-2-ubizjak@gmail.com
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
---
 include/linux/atomic/atomic-arch-fallback.h | 24 +++++++++++++++++++-
 include/linux/atomic/atomic-instrumented.h  | 20 ++++++++++++++++-
 scripts/atomic/gen-atomic-fallback.sh       |  4 +++-
 scripts/atomic/gen-atomic-instrumented.sh   |  2 +-
 4 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/include/linux/atomic/atomic-arch-fallback.h b/include/linux/atomic/atomic-arch-fallback.h
index 4226379..a6e4437 100644
--- a/include/linux/atomic/atomic-arch-fallback.h
+++ b/include/linux/atomic/atomic-arch-fallback.h
@@ -217,6 +217,28 @@
 
 #endif /* arch_try_cmpxchg64_relaxed */
 
+#ifndef arch_try_cmpxchg_local
+#define arch_try_cmpxchg_local(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = arch_cmpxchg_local((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_local */
+
+#ifndef arch_try_cmpxchg64_local
+#define arch_try_cmpxchg64_local(_ptr, _oldp, _new) \
+({ \
+	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+	___r = arch_cmpxchg64_local((_ptr), ___o, (_new)); \
+	if (unlikely(___r != ___o)) \
+		*___op = ___r; \
+	likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg64_local */
+
 #ifndef arch_atomic_read_acquire
 static __always_inline int
 arch_atomic_read_acquire(const atomic_t *v)
@@ -2646,4 +2668,4 @@ arch_atomic64_dec_if_positive(atomic64_t *v)
 #endif
 
 #endif /* _LINUX_ATOMIC_FALLBACK_H */
-// 00071fffa021cec66f6290d706d69c91df87bade
+// ad2e2b4d168dbc60a73922616047a9bfa446af36
diff --git a/include/linux/atomic/atomic-instrumented.h b/include/linux/atomic/atomic-instrumented.h
index 0496816..245ba66 100644
--- a/include/linux/atomic/atomic-instrumented.h
+++ b/include/linux/atomic/atomic-instrumented.h
@@ -2132,6 +2132,24 @@ atomic_long_dec_if_positive(atomic_long_t *v)
 	arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__); \
 })
 
+#define try_cmpxchg_local(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_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
+#define try_cmpxchg64_local(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_cmpxchg64_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+
 #define cmpxchg_double(ptr, ...) \
 ({ \
 	typeof(ptr) __ai_ptr = (ptr); \
@@ -2149,4 +2167,4 @@ atomic_long_dec_if_positive(atomic_long_t *v)
 })
 
 #endif /* _LINUX_ATOMIC_INSTRUMENTED_H */
-// 1b485de9cbaa4900de59e14ee2084357eaeb1c3a
+// 97fe4d79aa058d2164df824632cbc4f716d2a407
diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh
index 3a07695..6e853f0 100755
--- a/scripts/atomic/gen-atomic-fallback.sh
+++ b/scripts/atomic/gen-atomic-fallback.sh
@@ -225,6 +225,10 @@ for cmpxchg in "cmpxchg" "cmpxchg64"; do
 	gen_try_cmpxchg_fallbacks "${cmpxchg}"
 done
 
+for cmpxchg in "cmpxchg_local" "cmpxchg64_local"; do
+	gen_try_cmpxchg_fallback "${cmpxchg}" ""
+done
+
 grep '^[a-z]' "$1" | while read name meta args; do
 	gen_proto "${meta}" "${name}" "atomic" "int" ${args}
 done
diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh
index 77c0652..c8165e9 100755
--- a/scripts/atomic/gen-atomic-instrumented.sh
+++ b/scripts/atomic/gen-atomic-instrumented.sh
@@ -173,7 +173,7 @@ for xchg in "xchg" "cmpxchg" "cmpxchg64" "try_cmpxchg" "try_cmpxchg64"; do
 	done
 done
 
-for xchg in "cmpxchg_local" "cmpxchg64_local" "sync_cmpxchg"; do
+for xchg in "cmpxchg_local" "cmpxchg64_local" "sync_cmpxchg" "try_cmpxchg_local" "try_cmpxchg64_local" ; do
 	gen_xchg "${xchg}" "" ""
 	printf "\n"
 done