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author | Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | 2008-02-07 09:16:24 +0100 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-07 17:42:32 +0100 |
commit | 405321d3ab2b41960e2874f2f74609daffbc7a4c (patch) | |
tree | af0d51539011d57b2df0df6c69171433f9d60ff8 /include/asm-sparc/system.h | |
parent | Add cmpxchg_local to s390 (diff) | |
download | linux-405321d3ab2b41960e2874f2f74609daffbc7a4c.tar.xz linux-405321d3ab2b41960e2874f2f74609daffbc7a4c.zip |
Add cmpxchg_local to sparc, move __cmpxchg to system.h
Move cmpxchg and add cmpxchg_local to system.h.
Use the new generic cmpxchg_local (disables interrupt).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-sparc/system.h')
-rw-r--r-- | include/asm-sparc/system.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/include/asm-sparc/system.h b/include/asm-sparc/system.h index 2655d142b22d..45e47c159a6e 100644 --- a/include/asm-sparc/system.h +++ b/include/asm-sparc/system.h @@ -225,6 +225,54 @@ static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int return x; } +/* Emulate cmpxchg() the same way we emulate atomics, + * by hashing the object address and indexing into an array + * of spinlocks to get a bit of performance... + * + * See arch/sparc/lib/atomic32.c for implementation. + * + * Cribbed from <asm-parisc/atomic.h> + */ +#define __HAVE_ARCH_CMPXCHG 1 + +/* bug catcher for when unsupported size is used - won't link */ +extern void __cmpxchg_called_with_bad_pointer(void); +/* we only need to support cmpxchg of a u32 on sparc */ +extern unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_); + +/* don't worry...optimizer will get rid of most of this */ +static inline unsigned long +__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) +{ + switch (size) { + case 4: + return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_); + default: + __cmpxchg_called_with_bad_pointer(); + break; + } + return old; +} + +#define cmpxchg(ptr, o, n) \ +({ \ + __typeof__(*(ptr)) _o_ = (o); \ + __typeof__(*(ptr)) _n_ = (n); \ + (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ + (unsigned long)_n_, sizeof(*(ptr))); \ +}) + +#include <asm-generic/cmpxchg-local.h> + +/* + * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make + * them available. + */ +#define cmpxchg_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ + (unsigned long)(n), sizeof(*(ptr)))) +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) + extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn)); #endif /* __KERNEL__ */ |