diff options
Diffstat (limited to 'arch/x86/include/asm/cmpxchg_32.h')
| -rw-r--r-- | arch/x86/include/asm/cmpxchg_32.h | 218 |
1 files changed, 86 insertions, 132 deletions
diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index ee1931be659..ffb9bb6b6c3 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -8,14 +8,50 @@ * you need to test for the feature in boot_cpu_data. */ -#define xchg(ptr, v) \ - ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), sizeof(*(ptr)))) +extern void __xchg_wrong_size(void); + +/* + * Note: no "lock" prefix even on SMP: xchg always implies lock anyway + * Note 2: xchg has side effect, so that attribute volatile is necessary, + * but generally the primitive is invalid, *ptr is output argument. --ANK + */ struct __xchg_dummy { unsigned long a[100]; }; #define __xg(x) ((struct __xchg_dummy *)(x)) +#define __xchg(x, ptr, size) \ +({ \ + __typeof(*(ptr)) __x = (x); \ + switch (size) { \ + case 1: \ + asm volatile("xchgb %b0,%1" \ + : "=q" (__x) \ + : "m" (*__xg(ptr)), "0" (__x) \ + : "memory"); \ + break; \ + case 2: \ + asm volatile("xchgw %w0,%1" \ + : "=r" (__x) \ + : "m" (*__xg(ptr)), "0" (__x) \ + : "memory"); \ + break; \ + case 4: \ + asm volatile("xchgl %0,%1" \ + : "=r" (__x) \ + : "m" (*__xg(ptr)), "0" (__x) \ + : "memory"); \ + break; \ + default: \ + __xchg_wrong_size(); \ + } \ + __x; \ +}) + +#define xchg(ptr, v) \ + __xchg((v), (ptr), sizeof(*ptr)) + /* * The semantics of XCHGCMP8B are a bit strange, this is why * there is a loop and the loading of %%eax and %%edx has to @@ -71,57 +107,63 @@ static inline void __set_64bit_var(unsigned long long *ptr, (unsigned int)((value) >> 32)) \ : __set_64bit(ptr, ll_low((value)), ll_high((value)))) -/* - * Note: no "lock" prefix even on SMP: xchg always implies lock anyway - * Note 2: xchg has side effect, so that attribute volatile is necessary, - * but generally the primitive is invalid, *ptr is output argument. --ANK - */ -static inline unsigned long __xchg(unsigned long x, volatile void *ptr, - int size) -{ - switch (size) { - case 1: - asm volatile("xchgb %b0,%1" - : "=q" (x) - : "m" (*__xg(ptr)), "0" (x) - : "memory"); - break; - case 2: - asm volatile("xchgw %w0,%1" - : "=r" (x) - : "m" (*__xg(ptr)), "0" (x) - : "memory"); - break; - case 4: - asm volatile("xchgl %0,%1" - : "=r" (x) - : "m" (*__xg(ptr)), "0" (x) - : "memory"); - break; - } - return x; -} +extern void __cmpxchg_wrong_size(void); /* * Atomic compare and exchange. Compare OLD with MEM, if identical, * store NEW in MEM. Return the initial value in MEM. Success is * indicated by comparing RETURN with OLD. */ +#define __raw_cmpxchg(ptr, old, new, size, lock) \ +({ \ + __typeof__(*(ptr)) __ret; \ + __typeof__(*(ptr)) __old = (old); \ + __typeof__(*(ptr)) __new = (new); \ + switch (size) { \ + case 1: \ + asm volatile(lock "cmpxchgb %b1,%2" \ + : "=a"(__ret) \ + : "q"(__new), "m"(*__xg(ptr)), "0"(__old) \ + : "memory"); \ + break; \ + case 2: \ + asm volatile(lock "cmpxchgw %w1,%2" \ + : "=a"(__ret) \ + : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \ + : "memory"); \ + break; \ + case 4: \ + asm volatile(lock "cmpxchgl %1,%2" \ + : "=a"(__ret) \ + : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \ + : "memory"); \ + break; \ + default: \ + __cmpxchg_wrong_size(); \ + } \ + __ret; \ +}) + +#define __cmpxchg(ptr, old, new, size) \ + __raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX) + +#define __sync_cmpxchg(ptr, old, new, size) \ + __raw_cmpxchg((ptr), (old), (new), (size), "lock; ") + +#define __cmpxchg_local(ptr, old, new, size) \ + __raw_cmpxchg((ptr), (old), (new), (size), "") #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, old, new) \ + __cmpxchg((ptr), (old), (new), sizeof(*ptr)) + +#define sync_cmpxchg(ptr, old, new) \ + __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr)) + +#define cmpxchg_local(ptr, old, new) \ + __cmpxchg_local((ptr), (old), (new), sizeof(*ptr)) #endif #ifdef CONFIG_X86_CMPXCHG64 @@ -133,94 +175,6 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, (unsigned long long)(n))) #endif -static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, - unsigned long new, int size) -{ - unsigned long prev; - switch (size) { - case 1: - asm volatile(LOCK_PREFIX "cmpxchgb %b1,%2" - : "=a"(prev) - : "q"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - case 2: - asm volatile(LOCK_PREFIX "cmpxchgw %w1,%2" - : "=a"(prev) - : "r"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - case 4: - asm volatile(LOCK_PREFIX "cmpxchgl %1,%2" - : "=a"(prev) - : "r"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - } - return old; -} - -/* - * Always use locked operations when touching memory shared with a - * hypervisor, since the system may be SMP even if the guest kernel - * isn't. - */ -static inline unsigned long __sync_cmpxchg(volatile void *ptr, - unsigned long old, - unsigned long new, int size) -{ - unsigned long prev; - switch (size) { - case 1: - asm volatile("lock; cmpxchgb %b1,%2" - : "=a"(prev) - : "q"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - case 2: - asm volatile("lock; cmpxchgw %w1,%2" - : "=a"(prev) - : "r"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - case 4: - asm volatile("lock; cmpxchgl %1,%2" - : "=a"(prev) - : "r"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - } - return old; -} - -static inline unsigned long __cmpxchg_local(volatile void *ptr, - unsigned long old, - unsigned long new, int size) -{ - unsigned long prev; - switch (size) { - case 1: - asm volatile("cmpxchgb %b1,%2" - : "=a"(prev) - : "q"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - case 2: - asm volatile("cmpxchgw %w1,%2" - : "=a"(prev) - : "r"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - case 4: - asm volatile("cmpxchgl %1,%2" - : "=a"(prev) - : "r"(new), "m"(*__xg(ptr)), "0"(old) - : "memory"); - return prev; - } - return old; -} - static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long long old, unsigned long long new) |