Re: [patch 04/28] Add cmpxchg64 and cmpxchg64_local to mips

Ralf Baechle
2007-10-31T18:37:09Z

On Wed, Oct 31, 2007 at 09:19:35AM -0400, Mathieu Desnoyers wrote:

> * Ralf Baechle (ralf@linux-mips.org) wrote:
> > This implementation means cmpxchg64_local will also silently take 32-bit
> > arguments without making noises at compile time. I think it should.
> >
>
> Something along those lines ? I've fixed the other architectures too.
>
>
> Add cmpxchg64 and cmpxchg64_local to mips
>
> Make sure that at least cmpxchg64_local is available on all architectures to use
> for unsigned long long values.
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> CC: ralf@linux-mips.org
> CC linux-mips@linux-mips.org
> ---
> include/asm-mips/cmpxchg.h | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> Index: linux-2.6-lttng/include/asm-mips/cmpxchg.h
> ===================================================================
> --- linux-2.6-lttng.orig/include/asm-mips/cmpxchg.h 2007-10-31 09:14:10.000000000 -0400
> +++ linux-2.6-lttng/include/asm-mips/cmpxchg.h 2007-10-31 09:15:35.000000000 -0400
> @@ -104,4 +104,21 @@ extern void __cmpxchg_called_with_bad_po
> #define cmpxchg(ptr, old, new) __cmpxchg(ptr, old, new, smp_llsc_mb())
> #define cmpxchg_local(ptr, old, new) __cmpxchg(ptr, old, new, )
>
> +#define cmpxchg64(ptr,o,n) \
> + ({ \
> + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
> + cmpxchg((ptr),(o),(n)); \
> + })
> +
> +#ifdef CONFIG_64BIT
> +#define cmpxchg64_local(ptr,o,n) \
> + ({ \
> + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
> + cmpxchg_local((ptr),(o),(n)); \
> + })
> +#else
> +#include <asm-generic/cmpxchg-local.h>
> +#define cmpxchg64_local(ptr,o,n) __cmpxchg64_local_generic((ptr),(o),(n))
> +#endif
> +
> #endif /* __ASM_CMPXCHG_H */

That looks reasonable I think.

Ralf