146 lines
3.4 KiB
C
146 lines
3.4 KiB
C
/* 64-bit atomic xchg() and cmpxchg() definitions.
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*
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* Copyright (C) 1996, 1997, 2000 David S. Miller (davem@redhat.com)
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*/
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#ifndef __ARCH_SPARC64_CMPXCHG__
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#define __ARCH_SPARC64_CMPXCHG__
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static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
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{
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unsigned long tmp1, tmp2;
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__asm__ __volatile__(
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" mov %0, %1\n"
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"1: lduw [%4], %2\n"
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" cas [%4], %2, %0\n"
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" cmp %2, %0\n"
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" bne,a,pn %%icc, 1b\n"
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" mov %1, %0\n"
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: "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
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: "0" (val), "r" (m)
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: "cc", "memory");
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return val;
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}
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static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
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{
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unsigned long tmp1, tmp2;
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__asm__ __volatile__(
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" mov %0, %1\n"
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"1: ldx [%4], %2\n"
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" casx [%4], %2, %0\n"
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" cmp %2, %0\n"
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" bne,a,pn %%xcc, 1b\n"
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" mov %1, %0\n"
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: "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
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: "0" (val), "r" (m)
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: "cc", "memory");
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return val;
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}
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#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
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extern void __xchg_called_with_bad_pointer(void);
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static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
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int size)
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{
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switch (size) {
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case 4:
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return xchg32(ptr, x);
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case 8:
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return xchg64(ptr, x);
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}
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__xchg_called_with_bad_pointer();
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return x;
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}
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/*
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* Atomic compare and exchange. Compare OLD with MEM, if identical,
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* store NEW in MEM. Return the initial value in MEM. Success is
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* indicated by comparing RETURN with OLD.
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*/
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#include <asm-generic/cmpxchg-local.h>
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#define __HAVE_ARCH_CMPXCHG 1
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static inline unsigned long
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__cmpxchg_u32(volatile int *m, int old, int new)
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{
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__asm__ __volatile__("cas [%2], %3, %0"
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: "=&r" (new)
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: "0" (new), "r" (m), "r" (old)
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: "memory");
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return new;
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}
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static inline unsigned long
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__cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
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{
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__asm__ __volatile__("casx [%2], %3, %0"
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: "=&r" (new)
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: "0" (new), "r" (m), "r" (old)
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: "memory");
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return new;
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}
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/* This function doesn't exist, so you'll get a linker error
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if something tries to do an invalid cmpxchg(). */
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extern void __cmpxchg_called_with_bad_pointer(void);
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static inline unsigned long
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__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
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{
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switch (size) {
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case 4:
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return __cmpxchg_u32(ptr, old, new);
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case 8:
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return __cmpxchg_u64(ptr, old, new);
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}
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__cmpxchg_called_with_bad_pointer();
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return old;
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}
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#define cmpxchg(ptr,o,n) \
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({ \
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__typeof__(*(ptr)) _o_ = (o); \
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__typeof__(*(ptr)) _n_ = (n); \
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(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
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(unsigned long)_n_, sizeof(*(ptr))); \
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})
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/*
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* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
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* them available.
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*/
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static inline unsigned long __cmpxchg_local(volatile void *ptr,
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unsigned long old,
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unsigned long new, int size)
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{
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switch (size) {
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case 4:
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case 8: return __cmpxchg(ptr, old, new, size);
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default:
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return __cmpxchg_local_generic(ptr, old, new, size);
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}
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return old;
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}
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#define cmpxchg_local(ptr, o, n) \
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((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
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(unsigned long)(n), sizeof(*(ptr))))
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#define cmpxchg64_local(ptr, o, n) \
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({ \
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BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
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cmpxchg_local((ptr), (o), (n)); \
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})
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#endif /* __ARCH_SPARC64_CMPXCHG__ */
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