Comment 8 for bug 1324762

Okay, git bisect says this is the first offending commit:

> dc9c3ed611922e769b1fd595f8f99a93d69c026d is the first bad commit
> commit dc9c3ed611922e769b1fd595f8f99a93d69c026d
> Author: Borislav Petkov <email address hidden>
> Date: Thu Oct 31 17:25:08 2013 +0100
>
> x86/efi: Runtime services virtual mapping
>
> BugLink: http://bugs.launchpad.net/bugs/1297658
>
> We map the EFI regions needed for runtime services non-contiguously,
> with preserved alignment on virtual addresses starting from -4G down
> for a total max space of 64G. This way, we provide for stable runtime
> services addresses across kernels so that a kexec'd kernel can still use
> them.
>
> Thus, they're mapped in a separate pagetable so that we don't pollute
> the kernel namespace.
>
> Add an efi= kernel command line parameter for passing miscellaneous
> options and chicken bits from the command line.
>
> While at it, add a chicken bit called "efi=old_map" which can be used as
> a fallback to the old runtime services mapping method in case there's
> some b0rkage with a particular EFI implementation (haha, it is hard to
> hold up the sarcasm here...).
>
> Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt.
>
> Signed-off-by: Borislav Petkov <email address hidden>
> Signed-off-by: Matt Fleming <email address hidden>
> (cherry picked from commit d2f7cbe7b26a74dbbbf8f325b2a6fd01bc34032c)
> Signed-off-by: Tim Gardner <email address hidden>
>
> :040000 040000 52f7a3e427111f66f65fcb67b1d010cee7e5121f 1200735ebee4c3272d1e3eedfc00c7150d17e276 M Documentation
> :040000 040000 21376a74b6a2dc5dbe5b581677830b90bec72e49 95678fbb2d7178afb7866daf706dd7706d8da7e6 M arch
> :040000 040000 bf1515bb7d32745424abf75d8ce58340f482e88c 59013df8e2ea1c112d96b982105b469917864c8f M include