On Sat, Feb 01, 2020 at 08:27:03AM +0100, Christophe Leroy wrote:
> Le 31/01/2020 à 20:38, Segher Boessenkool a écrit :
> >On Fri, Jan 31, 2020 at 05:15:20PM +0100, Christophe Leroy wrote:
> >>Le 31/01/2020 à 16:51, Segher Boessenkool a écrit :
> >>>On Fri, Jan 31, 2020 at 03:37:34PM +0000, Christophe Leroy wrote:
> >>>>When the range is a single page, do a page flush instead.
> >>>
> >>>>+ start &= PAGE_MASK;
> >>>>+ end = (end - 1) | ~PAGE_MASK;
> >>>> if (!Hash) {
> >>>>- _tlbia();
> >>>>+ if (end - start == PAGE_SIZE)
> >>>>+ _tlbie(start);
> >>>>+ else
> >>>>+ _tlbia();
> >>>> return;
> >>>> }
> >>>
> >>>For just one page, you get end - start == 0 actually?
> >>
> >>Oops, good catch.
> >>
> >>Indeed you don't get PAGE_SIZE but (PAGE_SIZE - 1) for just one page.
> >
> >You have all low bits masked off in both start and end, so you get zero.
> >You could make the condion read "if (start == end)?
>
> No, in end the low bits are set, that's a BIT OR with ~PAGE_MASK, so it
> sets all low bits to 1.
Oh, wow, yes, I cannot read apparently.
Maybe there are some ROUND_DOWN and ROUND_UP macros you could use?
Segher
