On Wed, 20 Nov 2013 09:01:44 +1100, Benjamin Herrenschmidt benh@kernel.crashing.org wrote:
On Tue, 2013-11-19 at 15:14 +0000, Grant Likely wrote:
The proposal look good for me. I'm not convinced that we really need the support for 'reg' property, as the fixed memory region is a special case of generic dynamic allocation specified by the size and alloc-ranges, but I assume that there have been already a long discussion about this, so I accept the common consensus.
It is absolutely necessary for some use cases. For example, a framebuffer enabled by firmware and passed onto the kernel for flicker-free boot. Some platforms have fixed regions that cannot be moved up.
Arguably that could be covered with alloc-range and size by making the range be the reg property content basically (and thus size == size of range) but I prefer the reg property, it's a clearer statement of intent.
True, but I agree on liking 'reg'. Plus I suspect that the simplest implementation will resolve the size+alloc-ranges property into a generated 'reg' property during early boot so that the existing decode APIs work on any reserved range. :-)
g.