Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [RFC PATCH 4/4] ARM: Xilinx: Adding Xilinx board support | Date | Tue, 3 May 2011 09:58:14 +0200 |
| |
On Tuesday 03 May 2011 01:01:18 Russell King - ARM Linux wrote: > It is preferable to use the same mapping, as it ensures that you're not > going to create incompatible aliases.
Is aliasing a problem for MMIO mappings? I would think that you can ioremap registers anywhere and as often as you want because they are never cacheable.
> But, before we get too bogged down with this, please realise that it is > possible to setup early mappings from the device tree for things like the > SCU. Maybe not using ioremap(), but I'm sure we can find some way to use > the iotable_init() stuff to setup some early mappings from DT for this > stuff.
Good point. It doesn't really matter how the entries get into the page table, whether you call it ioremap, iotable_init, create_mapping or ioremap_early. What matters is that we don't hardcode the physical address in the board code, because that limits the possible reuse on other device tree enabled targets.
Arnd
| |