On Wed, Jun 26, 2013 at 11:23:50PM +0200, Arnd Bergmann wrote: > > Is this an issue here, since (unlike x86) this early_ioremap only works > > before paging_init()? > > The main problem is that the total fixmap size is only around 900kb, > and we want to reserve at least 64kb per cpu for kmap_atomic. > If you want to fit multiple 128kb mappings in there, you run out of > space really fast. Sorry, I still don't get it. Are you saying that kmap_atomic is available before kmap_init() (in paging_init())? If not, all of my mappings are discarded (well, abandoned to be more correct), so I don't see how it affects kmap. > > > 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? > > I don't know what the requirements are, but the idea with iotable > is that the mappings stay around at run time, while it seems you want > to discard them at some point. Indeed - almost immediately. x86 early_ioremap can coexist with kmap; the intent of my implementation is to use the kmap region only before kmap is available. / 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