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Diffstat (limited to 'arch/s390/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/s390/include/asm/cmpxchg.h | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/arch/s390/include/asm/cmpxchg.h b/arch/s390/include/asm/cmpxchg.h new file mode 100644 index 0000000..4052df9 --- /dev/null +++ b/arch/s390/include/asm/cmpxchg.h @@ -0,0 +1,205 @@ +/* + * Copyright IBM Corp. 1999, 2011 + * + * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, + */ + +#ifndef __ASM_CMPXCHG_H +#define __ASM_CMPXCHG_H + +#include <linux/types.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 << shift), "d" (~(255 << 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 << shift), "d" (~(65535 << 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; \ +}) + +/* + * 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 *) ptr) + : "d" (old << shift), "d" (new << shift), + "d" (~(255 << shift)), "Q" (*(int *) ptr) + : "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 *) ptr) + : "d" (old << shift), "d" (new << shift), + "d" (~(65535 << shift)), "Q" (*(int *) ptr) + : "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)))__cmpxchg((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))) + +#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)))__cmpxchg_local((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))) +#ifdef CONFIG_64BIT +#define cmpxchg64_local(ptr, o, n) \ +({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + cmpxchg_local((ptr), (o), (n)); \ +}) +#else +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +#endif + +#endif /* __ASM_CMPXCHG_H */ |