Re: [PATCH 7/9] atomic.h : powerpc

Mathieu Desnoyers
2006-12-21T03:29:31Z

* Benjamin Herrenschmidt (benh@kernel.crashing.org) wrote:
>
> > +
> > +/**
> > + * atomic64_add_unless - add unless the number is a given value
> > + * @v: pointer of type atomic64_t
> > + * @a: the amount to add to v...
> > + * @u: ...unless v is equal to u.
> > + *
> > + * Atomically adds @a to @v, so long as it was not @u.
> > + * Returns non-zero if @v was not @u, and zero otherwise.
> > + */
> > +static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
> > +{
> > + long t;
> > +
> > + __asm__ __volatile__ (
> > + LWSYNC_ON_SMP
> > +"1: ldarx %0,0,%1 # atomic_add_unless\n\
> > + cmpd 0,%0,%3 \n\
> > + beq- 2f \n\
> > + add %0,%2,%0 \n"
> > + PPC405_ERR77(0,%2)
> > +" stdcx. %0,0,%1 \n\
> > + bne- 1b \n"
> > + ISYNC_ON_SMP
> > +" subf %0,%2,%0 \n\
> > +2:"
> > + : "=&r" (t)
> > + : "r" (&v->counter), "r" (a), "r" (u)
> > + : "cc", "memory");
> > +
> > + return t != u;
> > +}
> > +
>
> You shouldn't try to define those when building 32 bits code... Also,
> the PPC405 errata, as it's name implies, is specific to 405 cores which
> are all 32 bits.
>
> Ben.
>
>

Hi Ben,

It is within a
#ifdef __powerpc64__
...
#endif /* __powerpc64__ */

so it should only build on 64 bits.

You are right about the PPC405 errata, it seems unnecessary.

The same is true for my asm-powerpc/local.h modification.

Thanks,

Mathieu

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