From b23e139d0b66c0216e7e9361a5021290395f504c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 31 May 2023 15:08:36 +0200 Subject: arch: Introduce arch_{,try_}_cmpxchg128{,_local}() For all architectures that currently support cmpxchg_double() implement the cmpxchg128() family of functions that is basically the same but with a saner interface. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Arnd Bergmann Reviewed-by: Mark Rutland Acked-by: Heiko Carstens Acked-by: Mark Rutland Tested-by: Mark Rutland Link: https://lore.kernel.org/r/20230531132323.452120708@infradead.org --- arch/x86/include/asm/cmpxchg_32.h | 3 +- arch/x86/include/asm/cmpxchg_64.h | 64 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 65 insertions(+), 2 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index 6ba80ce9438d..d12f9ed2e63a 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -103,6 +103,7 @@ static inline bool __try_cmpxchg64(volatile u64 *ptr, u64 *pold, u64 new) #endif -#define system_has_cmpxchg_double() boot_cpu_has(X86_FEATURE_CX8) +#define system_has_cmpxchg_double() boot_cpu_has(X86_FEATURE_CX8) +#define system_has_cmpxchg64() boot_cpu_has(X86_FEATURE_CX8) #endif /* _ASM_X86_CMPXCHG_32_H */ diff --git a/arch/x86/include/asm/cmpxchg_64.h b/arch/x86/include/asm/cmpxchg_64.h index 0d3beb27b7fe..fe2910729e6c 100644 --- a/arch/x86/include/asm/cmpxchg_64.h +++ b/arch/x86/include/asm/cmpxchg_64.h @@ -20,6 +20,68 @@ arch_try_cmpxchg((ptr), (po), (n)); \ }) -#define system_has_cmpxchg_double() boot_cpu_has(X86_FEATURE_CX16) +union __u128_halves { + u128 full; + struct { + u64 low, high; + }; +}; + +#define __arch_cmpxchg128(_ptr, _old, _new, _lock) \ +({ \ + union __u128_halves o = { .full = (_old), }, \ + n = { .full = (_new), }; \ + \ + asm volatile(_lock "cmpxchg16b %[ptr]" \ + : [ptr] "+m" (*(_ptr)), \ + "+a" (o.low), "+d" (o.high) \ + : "b" (n.low), "c" (n.high) \ + : "memory"); \ + \ + o.full; \ +}) + +static __always_inline u128 arch_cmpxchg128(volatile u128 *ptr, u128 old, u128 new) +{ + return __arch_cmpxchg128(ptr, old, new, LOCK_PREFIX); +} + +static __always_inline u128 arch_cmpxchg128_local(volatile u128 *ptr, u128 old, u128 new) +{ + return __arch_cmpxchg128(ptr, old, new,); +} + +#define __arch_try_cmpxchg128(_ptr, _oldp, _new, _lock) \ +({ \ + union __u128_halves o = { .full = *(_oldp), }, \ + n = { .full = (_new), }; \ + bool ret; \ + \ + asm volatile(_lock "cmpxchg16b %[ptr]" \ + CC_SET(e) \ + : CC_OUT(e) (ret), \ + [ptr] "+m" (*ptr), \ + "+a" (o.low), "+d" (o.high) \ + : "b" (n.low), "c" (n.high) \ + : "memory"); \ + \ + if (unlikely(!ret)) \ + *(_oldp) = o.full; \ + \ + likely(ret); \ +}) + +static __always_inline bool arch_try_cmpxchg128(volatile u128 *ptr, u128 *oldp, u128 new) +{ + return __arch_try_cmpxchg128(ptr, oldp, new, LOCK_PREFIX); +} + +static __always_inline bool arch_try_cmpxchg128_local(volatile u128 *ptr, u128 *oldp, u128 new) +{ + return __arch_try_cmpxchg128(ptr, oldp, new,); +} + +#define system_has_cmpxchg_double() boot_cpu_has(X86_FEATURE_CX16) +#define system_has_cmpxchg128() boot_cpu_has(X86_FEATURE_CX16) #endif /* _ASM_X86_CMPXCHG_64_H */ -- cgit v1.2.3