On Wed, Jun 26, 2013 at 08:52:09PM +0200, Arnd Bergmann wrote: > I made a similar suggestion to extending the use of fixmap recently, see > "Re: SCU registers mapping for CA9/CA5 cores". Russell pointed out that > fixmap is intentionally limited to just kmap_atomic uses at the moment > and changing that would potentially have a significant impact when we > run out of pages in the fixmap area. Is this an issue here, since (unlike x86) this early_ioremap only works before paging_init()? > The method we use on ARM normally is the iotable_init() function, which > requires hardcoding a virtual address at the moment. > > It might be nicer to change that code than to put early_ioremap into > fixmap. Note that early_ioremap in fixmap is a bit of a kludge on x86 > as well because it is very much /not/ a fixed mapping like the rest > of fixmap, they just use it because it's convenient. Yes, but they also only use it (at least the bits where I looked) for temporary mappings very early in the boot process. That is certainly how I use it. So at least my intention was to use it before kmap is even available. > Extending the iotable mechanism on ARM would be the convenient > solution for us I think. Could that easily be extended to give similar semantics sufficiently that we can progress with merging more of the UEFI and ACPI support together as common code with x86/ia64? / Leif -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html