diff options
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 17 | ||||
| -rw-r--r-- | include/asm-x86/cmpxchg_32.h | 122 |
2 files changed, 96 insertions, 43 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index cc8c501b9f3..867ff94579b 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -342,5 +342,22 @@ unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new) EXPORT_SYMBOL(cmpxchg_386_u32); #endif +#ifndef CONFIG_X86_CMPXCHG64 +unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new) +{ + u64 prev; + unsigned long flags; + + /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u64 *)ptr; + if (prev == old) + *(u64 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_486_u64); +#endif + // arch_initcall(intel_cpu_init); diff --git a/include/asm-x86/cmpxchg_32.h b/include/asm-x86/cmpxchg_32.h index f86ede28f6d..cea1dae288a 100644 --- a/include/asm-x86/cmpxchg_32.h +++ b/include/asm-x86/cmpxchg_32.h @@ -105,15 +105,24 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz #ifdef CONFIG_X86_CMPXCHG #define __HAVE_ARCH_CMPXCHG 1 -#define cmpxchg(ptr,o,n)\ - ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\ - (unsigned long)(n),sizeof(*(ptr)))) -#define sync_cmpxchg(ptr,o,n)\ - ((__typeof__(*(ptr)))__sync_cmpxchg((ptr),(unsigned long)(o),\ - (unsigned long)(n),sizeof(*(ptr)))) -#define cmpxchg_local(ptr,o,n)\ - ((__typeof__(*(ptr)))__cmpxchg_local((ptr),(unsigned long)(o),\ - (unsigned long)(n),sizeof(*(ptr)))) +#define cmpxchg(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))) +#define sync_cmpxchg(ptr, o, n) \ + ((__typeof__(*(ptr)))__sync_cmpxchg((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))) +#define cmpxchg_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))) +#endif + +#ifdef CONFIG_X86_CMPXCHG64 +#define cmpxchg64(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg64((ptr), (unsigned long long)(o), \ + (unsigned long long)(n))) +#define cmpxchg64_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg64_local((ptr), (unsigned long long)(o),\ + (unsigned long long)(n))) #endif static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, @@ -203,6 +212,34 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr, return old; } +static inline unsigned long long __cmpxchg64(volatile void *ptr, + unsigned long long old, unsigned long long new) +{ + unsigned long long prev; + __asm__ __volatile__(LOCK_PREFIX "cmpxchg8b %3" + : "=A"(prev) + : "b"((unsigned long)new), + "c"((unsigned long)(new >> 32)), + "m"(*__xg(ptr)), + "0"(old) + : "memory"); + return prev; +} + +static inline unsigned long long __cmpxchg64_local(volatile void *ptr, + unsigned long long old, unsigned long long new) +{ + unsigned long long prev; + __asm__ __volatile__("cmpxchg8b %3" + : "=A"(prev) + : "b"((unsigned long)new), + "c"((unsigned long)(new >> 32)), + "m"(*__xg(ptr)), + "0"(old) + : "memory"); + return prev; +} + #ifndef CONFIG_X86_CMPXCHG /* * Building a kernel capable running on 80386. It may be necessary to @@ -228,7 +265,7 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old, return old; } -#define cmpxchg(ptr,o,n) \ +#define cmpxchg(ptr, o, n) \ ({ \ __typeof__(*(ptr)) __ret; \ if (likely(boot_cpu_data.x86 > 3)) \ @@ -239,7 +276,7 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old, (unsigned long)(n), sizeof(*(ptr))); \ __ret; \ }) -#define cmpxchg_local(ptr,o,n) \ +#define cmpxchg_local(ptr, o, n) \ ({ \ __typeof__(*(ptr)) __ret; \ if (likely(boot_cpu_data.x86 > 3)) \ @@ -252,38 +289,37 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old, }) #endif -static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long long old, - unsigned long long new) -{ - unsigned long long prev; - __asm__ __volatile__(LOCK_PREFIX "cmpxchg8b %3" - : "=A"(prev) - : "b"((unsigned long)new), - "c"((unsigned long)(new >> 32)), - "m"(*__xg(ptr)), - "0"(old) - : "memory"); - return prev; -} +#ifndef CONFIG_X86_CMPXCHG64 +/* + * Building a kernel capable running on 80386 and 80486. It may be necessary + * to simulate the cmpxchg8b on the 80386 and 80486 CPU. + */ -static inline unsigned long long __cmpxchg64_local(volatile void *ptr, - unsigned long long old, unsigned long long new) -{ - unsigned long long prev; - __asm__ __volatile__("cmpxchg8b %3" - : "=A"(prev) - : "b"((unsigned long)new), - "c"((unsigned long)(new >> 32)), - "m"(*__xg(ptr)), - "0"(old) - : "memory"); - return prev; -} +extern unsigned long long cmpxchg_486_u64(volatile void *, u64, u64); + +#define cmpxchg64(ptr, o, n) \ +({ \ + __typeof__(*(ptr)) __ret; \ + if (likely(boot_cpu_data.x86 > 4)) \ + __ret = __cmpxchg64((ptr), (unsigned long long)(o), \ + (unsigned long long)(n)); \ + else \ + __ret = cmpxchg_486_u64((ptr), (unsigned long long)(o), \ + (unsigned long long)(n)); \ + __ret; \ +}) +#define cmpxchg64_local(ptr, o, n) \ +({ \ + __typeof__(*(ptr)) __ret; \ + if (likely(boot_cpu_data.x86 > 4)) \ + __ret = __cmpxchg64_local((ptr), (unsigned long long)(o), \ + (unsigned long long)(n)); \ + else \ + __ret = cmpxchg_486_u64((ptr), (unsigned long long)(o), \ + (unsigned long long)(n)); \ + __ret; \ +}) + +#endif -#define cmpxchg64(ptr,o,n)\ - ((__typeof__(*(ptr)))__cmpxchg64((ptr),(unsigned long long)(o),\ - (unsigned long long)(n))) -#define cmpxchg64_local(ptr,o,n)\ - ((__typeof__(*(ptr)))__cmpxchg64_local((ptr),(unsigned long long)(o),\ - (unsigned long long)(n))) #endif |