diff options
| -rw-r--r-- | arch/x86/include/asm/cmpxchg.h | 114 |
1 files changed, 36 insertions, 78 deletions
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index 49eade1..5488e10 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -33,60 +33,47 @@ extern void __add_wrong_size(void) #define __X86_CASE_Q -1 /* sizeof will never return -1 */ #endif +/* + * An exchange-type operation, which takes a value and a pointer, and + * returns a the old value. + */ +#define __xchg_op(ptr, arg, op, lock) \ + ({ \ + __typeof__ (*(ptr)) __ret = (arg); \ + switch (sizeof(*(ptr))) { \ + case __X86_CASE_B: \ + asm volatile (lock #op "b %b0, %1\n" \ + : "+r" (__ret), "+m" (*(ptr)) \ + : : "memory", "cc"); \ + break; \ + case __X86_CASE_W: \ + asm volatile (lock #op "w %w0, %1\n" \ + : "+r" (__ret), "+m" (*(ptr)) \ + : : "memory", "cc"); \ + break; \ + case __X86_CASE_L: \ + asm volatile (lock #op "l %0, %1\n" \ + : "+r" (__ret), "+m" (*(ptr)) \ + : : "memory", "cc"); \ + break; \ + case __X86_CASE_Q: \ + asm volatile (lock #op "q %q0, %1\n" \ + : "+r" (__ret), "+m" (*(ptr)) \ + : : "memory", "cc"); \ + break; \ + default: \ + __ ## op ## _wrong_size(); \ + } \ + __ret; \ + }) + /* * Note: no "lock" prefix even on SMP: xchg always implies lock anyway. * Since this is generally used to protect other memory information, we * use "asm volatile" and "memory" clobbers to prevent gcc from moving * information around. */ -#define __xchg(x, ptr, size) \ -({ \ - __typeof(*(ptr)) __x = (x); \ - switch (size) { \ - case __X86_CASE_B: \ - { \ - volatile u8 *__ptr = (volatile u8 *)(ptr); \ - asm volatile("xchgb %0,%1" \ - : "=q" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case __X86_CASE_W: \ - { \ - volatile u16 *__ptr = (volatile u16 *)(ptr); \ - asm volatile("xchgw %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case __X86_CASE_L: \ - { \ - volatile u32 *__ptr = (volatile u32 *)(ptr); \ - asm volatile("xchgl %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case __X86_CASE_Q: \ - { \ - volatile u64 *__ptr = (volatile u64 *)(ptr); \ - asm volatile("xchgq %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - default: \ - __xchg_wrong_size(); \ - } \ - __x; \ -}) - -#define xchg(ptr, v) \ - __xchg((v), (ptr), sizeof(*ptr)) +#define xchg(ptr, v) __xchg_op((ptr), (v), xchg, "") /* * Atomic compare and exchange. Compare OLD with MEM, if identical, @@ -167,36 +154,6 @@ extern void __add_wrong_size(void) __cmpxchg_local((ptr), (old), (new), sizeof(*ptr)) #endif -#define __xadd(ptr, inc, lock) \ - ({ \ - __typeof__ (*(ptr)) __ret = (inc); \ - switch (sizeof(*(ptr))) { \ - case __X86_CASE_B: \ - asm volatile (lock "xaddb %b0, %1\n" \ - : "+r" (__ret), "+m" (*(ptr)) \ - : : "memory", "cc"); \ - break; \ - case __X86_CASE_W: \ - asm volatile (lock "xaddw %w0, %1\n" \ - : "+r" (__ret), "+m" (*(ptr)) \ - : : "memory", "cc"); \ - break; \ - case __X86_CASE_L: \ - asm volatile (lock "xaddl %0, %1\n" \ - : "+r" (__ret), "+m" (*(ptr)) \ - : : "memory", "cc"); \ - break; \ - case __X86_CASE_Q: \ - asm volatile (lock "xaddq %q0, %1\n" \ - : "+r" (__ret), "+m" (*(ptr)) \ - : : "memory", "cc"); \ - break; \ - default: \ - __xadd_wrong_size(); \ - } \ - __ret; \ - }) - /* * xadd() adds "inc" to "*ptr" and atomically returns the previous * value of "*ptr". @@ -205,6 +162,7 @@ extern void __add_wrong_size(void) * xadd_sync() is always locked * xadd_local() is never locked */ +#define __xadd(ptr, inc, lock) __xchg_op((ptr), (inc), xadd, lock) #define xadd(ptr, inc) __xadd((ptr), (inc), LOCK_PREFIX) #define xadd_sync(ptr, inc) __xadd((ptr), (inc), "lock; ") #define xadd_local(ptr, inc) __xadd((ptr), (inc), "") |
