[PATCH 04/14] bus: mvebu-mbus: Add static window allocation to the DT binding

Arnd Bergmann
2013-06-12T22:20:30Z

On Thursday 13 June 2013, Jason Gunthorpe wrote:
> On Wed, Jun 12, 2013 at 11:52:32PM +0200, Arnd Bergmann wrote:
> > Whether that results in an optimum mapping or not depends on the actual
> > sizes for the child nodes. Since everything is a power-of-two size,
> > a first-fit algorithm actually isn't bad at all.
>
> The windows must be aligned to their size. eg 1M size window must be
> aligned to a 1M boundary.
>
> First fit only works if you allocate from largest alignment
> requirement to smallest, otherwise the worst case is something like
> nearly double the largest alignment wasted in alignment padding.

Yes, I realize that, which is why I said it depends on the actual sizes.
If you have a lot of windows that are all the same size and nothing larger,
the worst case isn't too bad.

Arnd