Re: do_div64 generic

[Andrew Morton <akpm@osdl.org>]

Bernardo Innocenti <bernie@develer.com> wrote:
>
> I see. do_div() which updates the dividend in-place did not quite apply
>  to the usage pattern of the new timer code.

This is getting silly.  The timer stuff has been an ongoing bug factory and
now it is colluding with the do_div() saga.

Can we just get the things working, without mangling every architecture
again?

>  > The using code tests for the existance of div_long_long_rem and uses
>  > the longer do_div() if it does not exist.
>  >
>  > Could you consider adding this to the generic code?
>  >
>  > /*
>  >   * (long)X = ((long long)divs) / (long)div
>  >   * (long)rem = ((long long)divs) % (long)div
>  >   *
>  >   * Warning, this will do an exception if X overflows.
>  >   */
>  > #define div_long_long_rem(a,b,c) div_ll_X_l_rem(a,b,c)
>  >
>  > extern inline long
>  > div_ll_X_l_rem(long long divs, long div, long *rem)
>  > {
>  > 	long dum2;
>  >        __asm__("divl %2":"=a"(dum2), "=d"(*rem)
>  >
>  >        :	"rm"(div), "A"(divs));
>  >
>  > 	return dum2;
>  >
>  > }
> 
>  Here's a patch that takes care of all architectures.

AFAICT, we can just rework posix-timers.c to use the standard do_div() and
be done with it, can we not?  ie: no div_long_long_rem(), no
div_ll_X_l_rem().  Just do_div().

Please use `static inline', not `extern inline', btw.