Re: [PATCH 2/5] Blackfin arch: SMP supporting patchset: Blackfin header files and machine common code

Nick Piggin
2008-11-19T07:05:34Z

On Wednesday 19 November 2008 17:56, Andrew Morton wrote:
> On Tue, 18 Nov 2008 17:05:05 +0800 Bryan Wu <cooloney@kernel.org> wrote:

> > +#define smp_mb__before_clear_bit() barrier()
> > +#define smp_mb__after_clear_bit() barrier()
> > +
> > +static inline void __set_bit(int nr, volatile unsigned long *addr)
> > +{
> > + int *a = (int *)addr;
> > + int mask;
> > +
> > + a += nr >> 5;
> > + mask = 1 << (nr & 0x1f);
> > + *a |= mask;
> > +}
> > +
> > +static inline void __clear_bit(int nr, volatile unsigned long *addr)
> > +{
> > + int *a = (int *)addr;
> > + int mask;
> > +
> > + a += nr >> 5;
> > + mask = 1 << (nr & 0x1f);
> > + *a &= ~mask;
> > +}
> > +
> > +static inline void __change_bit(int nr, volatile unsigned long *addr)
> > +{
> > + int mask;
> > + unsigned long *ADDR = (unsigned long *)addr;
> > +
> > + ADDR += nr >> 5;
> > + mask = 1 << (nr & 31);
> > + *ADDR ^= mask;
> > +}
>
> I'm surprised there isn't any generic code which can be used for the above.

include/asm-generic/bitops/non-atomic.h

> > ...
>
> Gad what a lot of code. I don't think I have time to read it all, sorry.

:) I don't know who is expected to. Cc'ing linux-arch for something
like this might attract some helpful comments.