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

Benjamin Herrenschmidt
2006-12-21T03:17:12Z

> +
> +/**
> + * 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.