Messages in this thread Patch in this message | | | From | Mark Rutland <> | Subject | [PATCH 12/26] locking/atomic: x86: add preprocessor symbols | Date | Mon, 22 May 2023 13:24:15 +0100 |
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Some atomics can be implemented in several different ways, e.g. FULL/ACQUIRE/RELEASE ordered atomics can be implemented in terms of RELAXED atomics, and ACQUIRE/RELEASE/RELAXED can be implemented in terms of FULL ordered atomics. Other atomics are optional, and don't exist in some configurations (e.g. not all architectures implement the 128-bit cmpxchg ops).
Subsequent patches will require that architectures define a preprocessor symbol for any atomic (or ordering variant) which is optional. This will make the fallback ifdeffery more robust, and simplify future changes.
Add the required definitions to arch/x86.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> --- arch/x86/include/asm/cmpxchg_64.h | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/x86/include/asm/cmpxchg_64.h b/arch/x86/include/asm/cmpxchg_64.h index 3e6e3eef701b3..44b08b53ab32f 100644 --- a/arch/x86/include/asm/cmpxchg_64.h +++ b/arch/x86/include/asm/cmpxchg_64.h @@ -45,11 +45,13 @@ static __always_inline u128 arch_cmpxchg128(volatile u128 *ptr, u128 old, u128 n { return __arch_cmpxchg128(ptr, old, new, LOCK_PREFIX); } +#define arch_cmpxchg128 arch_cmpxchg128 static __always_inline u128 arch_cmpxchg128_local(volatile u128 *ptr, u128 old, u128 new) { return __arch_cmpxchg128(ptr, old, new,); } +#define arch_cmpxchg128_local arch_cmpxchg128_local #define __arch_try_cmpxchg128(_ptr, _oldp, _new, _lock) \ ({ \ @@ -75,11 +77,13 @@ static __always_inline bool arch_try_cmpxchg128(volatile u128 *ptr, u128 *oldp, { return __arch_try_cmpxchg128(ptr, oldp, new, LOCK_PREFIX); } +#define arch_try_cmpxchg128 arch_try_cmpxchg128 static __always_inline bool arch_try_cmpxchg128_local(volatile u128 *ptr, u128 *oldp, u128 new) { return __arch_try_cmpxchg128(ptr, oldp, new,); } +#define arch_try_cmpxchg128_local arch_try_cmpxchg128_local #define system_has_cmpxchg128() boot_cpu_has(X86_FEATURE_CX16) -- 2.30.2
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