Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap

["H. Peter Anvin" <hpa@zytor.com>]

Ingo Molnar wrote:
> * H. Peter Anvin <hpa@zytor.com> wrote:
> 
>> I did a quick scan over the patchset (not quite awake yet, so I may 
>> very well have missed something), but it looks like EFI (again!) is 
>> the only user of ioremapping before paging_init().  This makes me 
>> wonder if that code can't be restructured so that isn't necessary.
> 
> i think that in general making access to unmapped memory a bit easier is 
> generally a good robustness idea as ACPI could be impacted by it as 
> well.
> 
> Fundamentally, paging_init() has obvious dependency on "figuring out the 
> memory setup" of the box, and "figuring out the memory setup" means 
> interpreting various data structures passed in by the BIOS - some of 
> which might be in not yet mapped areas or iommu areas (if we have to do 
> some early quirk). So having a robust implementation of ioremap_early() 
> sounds like a definitive plus.
> 

Fair enough.  If it's generally useful, I certainly have no objections.

	-hpa