[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 1/3] locking/generic: Add generic support for sync_try_cmpxchg and its fallback
Provide the generic sync_try_cmpxchg function from the raw_ prefixed version, also adding explicit instrumentation. The patch amends existing scripts to generate sync_try_cmpxchg locking primitive and its raw_sync_try_cmpxchg fallback, while leaving existing macros from try_cmpxchg family unchanged. The target can define its own arch_sync_try_cmpxchg to override the generic version of raw_sync_try_cmpxchg. This allows the target to generate more optimal assembly than the generic version. Additionally, the patch renames two scripts to better reflect whet they really do. Cc: Will Deacon <will@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Boqun Feng <boqun.feng@xxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx> --- v2: Improve commit description. --- include/linux/atomic/atomic-arch-fallback.h | 15 +++++++++- include/linux/atomic/atomic-instrumented.h | 10 ++++++- scripts/atomic/gen-atomic-fallback.sh | 33 +++++++++++---------- scripts/atomic/gen-atomic-instrumented.sh | 3 +- 4 files changed, 43 insertions(+), 18 deletions(-) diff --git a/include/linux/atomic/atomic-arch-fallback.h b/include/linux/atomic/atomic-arch-fallback.h index b83ef19da13d..5e95faa959c4 100644 --- a/include/linux/atomic/atomic-arch-fallback.h +++ b/include/linux/atomic/atomic-arch-fallback.h @@ -428,6 +428,19 @@ extern void raw_cmpxchg128_relaxed_not_implemented(void); #define raw_sync_cmpxchg arch_sync_cmpxchg +#ifdef arch_sync_try_cmpxchg +#define raw_sync_try_cmpxchg arch_sync_try_cmpxchg +#else +#define raw_sync_try_cmpxchg(_ptr, _oldp, _new) \ +({ \ + typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \ + ___r = raw_sync_cmpxchg((_ptr), ___o, (_new)); \ + if (unlikely(___r != ___o)) \ + *___op = ___r; \ + likely(___r == ___o); \ +}) +#endif + /** * raw_atomic_read() - atomic load with relaxed ordering * @v: pointer to atomic_t @@ -4649,4 +4662,4 @@ raw_atomic64_dec_if_positive(atomic64_t *v) } #endif /* _LINUX_ATOMIC_FALLBACK_H */ -// 2fdd6702823fa842f9cea57a002e6e4476ae780c +// eec048affea735b8464f58e6d96992101f8f85f1 diff --git a/include/linux/atomic/atomic-instrumented.h b/include/linux/atomic/atomic-instrumented.h index d401b406ef7c..54d7bbe0aeaa 100644 --- a/include/linux/atomic/atomic-instrumented.h +++ b/include/linux/atomic/atomic-instrumented.h @@ -4998,6 +4998,14 @@ atomic_long_dec_if_positive(atomic_long_t *v) raw_try_cmpxchg128_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \ }) +#define sync_try_cmpxchg(ptr, ...) \ +({ \ + typeof(ptr) __ai_ptr = (ptr); \ + kcsan_mb(); \ + instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \ + raw_sync_try_cmpxchg(__ai_ptr, __VA_ARGS__); \ +}) + #endif /* _LINUX_ATOMIC_INSTRUMENTED_H */ -// 1568f875fef72097413caab8339120c065a39aa4 +// 2cc4bc990fef44d3836ec108f11b610f3f438184 diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh index a45154cefa48..f80d69cfeb1f 100755 --- a/scripts/atomic/gen-atomic-fallback.sh +++ b/scripts/atomic/gen-atomic-fallback.sh @@ -223,14 +223,15 @@ gen_xchg_fallbacks() gen_try_cmpxchg_fallback() { + local prefix="$1"; shift local cmpxchg="$1"; shift; - local order="$1"; shift; + local suffix="$1"; shift; cat <<EOF -#define raw_try_${cmpxchg}${order}(_ptr, _oldp, _new) \\ +#define raw_${prefix}try_${cmpxchg}${suffix}(_ptr, _oldp, _new) \\ ({ \\ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \\ - ___r = raw_${cmpxchg}${order}((_ptr), ___o, (_new)); \\ + ___r = raw_${prefix}${cmpxchg}${suffix}((_ptr), ___o, (_new)); \\ if (unlikely(___r != ___o)) \\ *___op = ___r; \\ likely(___r == ___o); \\ @@ -259,11 +260,11 @@ gen_try_cmpxchg_order_fallback() fi printf "#else\n" - gen_try_cmpxchg_fallback "${cmpxchg}" "${order}" + gen_try_cmpxchg_fallback "" "${cmpxchg}" "${order}" printf "#endif\n\n" } -gen_try_cmpxchg_fallbacks() +gen_try_cmpxchg_order_fallbacks() { local cmpxchg="$1"; shift; @@ -272,15 +273,17 @@ gen_try_cmpxchg_fallbacks() done } -gen_cmpxchg_local_fallbacks() +gen_def_and_try_cmpxchg_fallback() { + local prefix="$1"; shift local cmpxchg="$1"; shift + local suffix="$1"; shift - printf "#define raw_${cmpxchg} arch_${cmpxchg}\n\n" - printf "#ifdef arch_try_${cmpxchg}\n" - printf "#define raw_try_${cmpxchg} arch_try_${cmpxchg}\n" + printf "#define raw_${prefix}${cmpxchg}${suffix} arch_${prefix}${cmpxchg}${suffix}\n\n" + printf "#ifdef arch_${prefix}try_${cmpxchg}${suffix}\n" + printf "#define raw_${prefix}try_${cmpxchg}${suffix} arch_${prefix}try_${cmpxchg}${suffix}\n" printf "#else\n" - gen_try_cmpxchg_fallback "${cmpxchg}" "" + gen_try_cmpxchg_fallback "${prefix}" "${cmpxchg}" "${suffix}" printf "#endif\n\n" } @@ -302,15 +305,15 @@ for xchg in "xchg" "cmpxchg" "cmpxchg64" "cmpxchg128"; do done for cmpxchg in "cmpxchg" "cmpxchg64" "cmpxchg128"; do - gen_try_cmpxchg_fallbacks "${cmpxchg}" + gen_try_cmpxchg_order_fallbacks "${cmpxchg}" done -for cmpxchg in "cmpxchg_local" "cmpxchg64_local" "cmpxchg128_local"; do - gen_cmpxchg_local_fallbacks "${cmpxchg}" "" +for cmpxchg in "cmpxchg" "cmpxchg64" "cmpxchg128"; do + gen_def_and_try_cmpxchg_fallback "" "${cmpxchg}" "_local" done -for cmpxchg in "sync_cmpxchg"; do - printf "#define raw_${cmpxchg} arch_${cmpxchg}\n\n" +for cmpxchg in "cmpxchg"; do + gen_def_and_try_cmpxchg_fallback "sync_" "${cmpxchg}" "" done grep '^[a-z]' "$1" | while read name meta args; do diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh index 8f8f8e3b20f9..592f3ec89b5f 100755 --- a/scripts/atomic/gen-atomic-instrumented.sh +++ b/scripts/atomic/gen-atomic-instrumented.sh @@ -169,7 +169,8 @@ for xchg in "xchg" "cmpxchg" "cmpxchg64" "cmpxchg128" "try_cmpxchg" "try_cmpxchg done done -for xchg in "cmpxchg_local" "cmpxchg64_local" "cmpxchg128_local" "sync_cmpxchg" "try_cmpxchg_local" "try_cmpxchg64_local" "try_cmpxchg128_local"; do +for xchg in "cmpxchg_local" "cmpxchg64_local" "cmpxchg128_local" "sync_cmpxchg" \ + "try_cmpxchg_local" "try_cmpxchg64_local" "try_cmpxchg128_local" "sync_try_cmpxchg"; do gen_xchg "${xchg}" "" printf "\n" done -- 2.41.0
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