#include <linux/types.h>
#include <linux/bug.h>
-extern void __xchg_called_with_bad_pointer(void);
-
-static inline unsigned long __xchg(unsigned long x, void *ptr, int size)
-{
- unsigned long addr, old;
- int shift;
-
- switch (size) {
- case 1:
- addr = (unsigned long) ptr;
- shift = (3 ^ (addr & 3)) << 3;
- addr ^= addr & 3;
- asm volatile(
- " l %0,%4\n"
- "0: lr 0,%0\n"
- " nr 0,%3\n"
- " or 0,%2\n"
- " cs %0,0,%4\n"
- " jl 0b\n"
- : "=&d" (old), "=Q" (*(int *) addr)
- : "d" ((x & 0xff) << shift), "d" (~(0xff << shift)),
- "Q" (*(int *) addr) : "memory", "cc", "0");
- return old >> shift;
- case 2:
- addr = (unsigned long) ptr;
- shift = (2 ^ (addr & 2)) << 3;
- addr ^= addr & 2;
- asm volatile(
- " l %0,%4\n"
- "0: lr 0,%0\n"
- " nr 0,%3\n"
- " or 0,%2\n"
- " cs %0,0,%4\n"
- " jl 0b\n"
- : "=&d" (old), "=Q" (*(int *) addr)
- : "d" ((x & 0xffff) << shift), "d" (~(0xffff << shift)),
- "Q" (*(int *) addr) : "memory", "cc", "0");
- return old >> shift;
- case 4:
- asm volatile(
- " l %0,%3\n"
- "0: cs %0,%2,%3\n"
- " jl 0b\n"
- : "=&d" (old), "=Q" (*(int *) ptr)
- : "d" (x), "Q" (*(int *) ptr)
- : "memory", "cc");
- return old;
-#ifdef CONFIG_64BIT
- case 8:
- asm volatile(
- " lg %0,%3\n"
- "0: csg %0,%2,%3\n"
- " jl 0b\n"
- : "=&d" (old), "=m" (*(long *) ptr)
- : "d" (x), "Q" (*(long *) ptr)
- : "memory", "cc");
- return old;
-#endif /* CONFIG_64BIT */
- }
- __xchg_called_with_bad_pointer();
- return x;
-}
-
-#define xchg(ptr, x) \
-({ \
- __typeof__(*(ptr)) __ret; \
- __ret = (__typeof__(*(ptr))) \
- __xchg((unsigned long)(x), (void *)(ptr), sizeof(*(ptr)));\
- __ret; \
+#define cmpxchg(ptr, o, n) \
+({ \
+ __typeof__(*(ptr)) __o = (o); \
+ __typeof__(*(ptr)) __n = (n); \
+ (__typeof__(*(ptr))) __sync_val_compare_and_swap((ptr),__o,__n);\
})
-/*
- * 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 __HAVE_ARCH_CMPXCHG
-
-extern void __cmpxchg_called_with_bad_pointer(void);
-
-static inline unsigned long __cmpxchg(void *ptr, unsigned long old,
- unsigned long new, int size)
-{
- unsigned long addr, prev, tmp;
- int shift;
-
- switch (size) {
- case 1:
- addr = (unsigned long) ptr;
- shift = (3 ^ (addr & 3)) << 3;
- addr ^= addr & 3;
- asm volatile(
- " l %0,%2\n"
- "0: nr %0,%5\n"
- " lr %1,%0\n"
- " or %0,%3\n"
- " or %1,%4\n"
- " cs %0,%1,%2\n"
- " jnl 1f\n"
- " xr %1,%0\n"
- " nr %1,%5\n"
- " jnz 0b\n"
- "1:"
- : "=&d" (prev), "=&d" (tmp), "+Q" (*(int *) addr)
- : "d" ((old & 0xff) << shift),
- "d" ((new & 0xff) << shift),
- "d" (~(0xff << shift))
- : "memory", "cc");
- return prev >> shift;
- case 2:
- addr = (unsigned long) ptr;
- shift = (2 ^ (addr & 2)) << 3;
- addr ^= addr & 2;
- asm volatile(
- " l %0,%2\n"
- "0: nr %0,%5\n"
- " lr %1,%0\n"
- " or %0,%3\n"
- " or %1,%4\n"
- " cs %0,%1,%2\n"
- " jnl 1f\n"
- " xr %1,%0\n"
- " nr %1,%5\n"
- " jnz 0b\n"
- "1:"
- : "=&d" (prev), "=&d" (tmp), "+Q" (*(int *) addr)
- : "d" ((old & 0xffff) << shift),
- "d" ((new & 0xffff) << shift),
- "d" (~(0xffff << shift))
- : "memory", "cc");
- return prev >> shift;
- case 4:
- asm volatile(
- " cs %0,%3,%1\n"
- : "=&d" (prev), "=Q" (*(int *) ptr)
- : "0" (old), "d" (new), "Q" (*(int *) ptr)
- : "memory", "cc");
- return prev;
-#ifdef CONFIG_64BIT
- case 8:
- asm volatile(
- " csg %0,%3,%1\n"
- : "=&d" (prev), "=Q" (*(long *) ptr)
- : "0" (old), "d" (new), "Q" (*(long *) ptr)
- : "memory", "cc");
- return prev;
-#endif /* CONFIG_64BIT */
- }
- __cmpxchg_called_with_bad_pointer();
- return old;
-}
-
-#define cmpxchg(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) __ret; \
- __ret = (__typeof__(*(ptr))) \
- __cmpxchg((ptr), (unsigned long)(o), (unsigned long)(n), \
- sizeof(*(ptr))); \
- __ret; \
-})
+#define cmpxchg64 cmpxchg
+#define cmpxchg_local cmpxchg
+#define cmpxchg64_local cmpxchg
-#ifdef CONFIG_64BIT
-#define cmpxchg64(ptr, o, n) \
+#define xchg(ptr, x) \
({ \
- cmpxchg((ptr), (o), (n)); \
+ __typeof__(ptr) __ptr = (ptr); \
+ __typeof__(*(ptr)) __old; \
+ do { \
+ __old = *__ptr; \
+ } while (!__sync_bool_compare_and_swap(__ptr, __old, x)); \
+ __old; \
})
-#else /* CONFIG_64BIT */
-static inline unsigned long long __cmpxchg64(void *ptr,
- unsigned long long old,
- unsigned long long new)
-{
- register_pair rp_old = {.pair = old};
- register_pair rp_new = {.pair = new};
- unsigned long long *ullptr = ptr;
- asm volatile(
- " cds %0,%2,%1"
- : "+d" (rp_old), "+Q" (*ullptr)
- : "d" (rp_new)
- : "memory", "cc");
- return rp_old.pair;
-}
-
-#define cmpxchg64(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) __ret; \
- __ret = (__typeof__(*(ptr))) \
- __cmpxchg64((ptr), \
- (unsigned long long)(o), \
- (unsigned long long)(n)); \
- __ret; \
-})
-#endif /* CONFIG_64BIT */
+#define __HAVE_ARCH_CMPXCHG
#define __cmpxchg_double_op(p1, p2, o1, o2, n1, n2, insn) \
({ \
#define system_has_cmpxchg_double() 1
-#include <asm-generic/cmpxchg-local.h>
-
-static inline unsigned long __cmpxchg_local(void *ptr,
- unsigned long old,
- unsigned long new, int size)
-{
- switch (size) {
- case 1:
- case 2:
- case 4:
-#ifdef CONFIG_64BIT
- case 8:
-#endif
- return __cmpxchg(ptr, old, new, size);
- default:
- return __cmpxchg_local_generic(ptr, old, new, size);
- }
-
- return old;
-}
-
-/*
- * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
- * them available.
- */
-#define cmpxchg_local(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) __ret; \
- __ret = (__typeof__(*(ptr))) \
- __cmpxchg_local((ptr), (unsigned long)(o), \
- (unsigned long)(n), sizeof(*(ptr))); \
- __ret; \
-})
-
-#define cmpxchg64_local(ptr, o, n) cmpxchg64((ptr), (o), (n))
-
#endif /* __ASM_CMPXCHG_H */
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