Add cmpxchg_local to ppc
Add a local processor version of cmpxchg for ppc. Implements __cmpxchg_u32_local and uses it for 32 bits cmpxchg_local. It uses the non NMI safe cmpxchg_local_generic for 1, 2 and 8 bytes cmpxchg_local. Signed-off-by: Gunnar Larisch <gl@denx.de> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Kumar Gala <galak@gate.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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1 changed files with 49 additions and 2 deletions
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@ -209,12 +209,34 @@ __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
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return prev;
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}
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static inline unsigned long
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__cmpxchg_u32_local(volatile unsigned int *p, unsigned int old,
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unsigned int new)
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{
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unsigned int prev;
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__asm__ __volatile__ ("\n\
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1: lwarx %0,0,%2 \n\
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cmpw 0,%0,%3 \n\
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bne 2f \n"
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PPC405_ERR77(0,%2)
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" stwcx. %4,0,%2 \n\
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bne- 1b\n"
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"2:"
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: "=&r" (prev), "=m" (*p)
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: "r" (p), "r" (old), "r" (new), "m" (*p)
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: "cc", "memory");
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return prev;
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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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__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
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unsigned int size)
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{
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switch (size) {
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case 4:
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@ -228,7 +250,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
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return old;
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}
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#define cmpxchg(ptr,o,n) \
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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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@ -236,6 +258,31 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
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(unsigned long)_n_, sizeof(*(ptr))); \
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})
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#include <asm-generic/cmpxchg-local.h>
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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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return __cmpxchg_u32_local(ptr, old, new);
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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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/*
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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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#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) __cmpxchg64_local_generic((ptr), (o), (n))
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#define arch_align_stack(x) (x)
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#endif /* __KERNEL__ */
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