Re: [PATCH 1/2] x86/efi: Correct a tiny mistake in code comment

[Baoquan He]

Forgot cc to Boris, add him.

On 03/08/17 at 04:18pm, Dave Young wrote:
> On 03/08/17 at 03:47pm, Baoquan He wrote:
> > EFI allocate runtime services regions down from EFI_VA_START, -4G.
> > It should be top-down handling.
> > 
> > Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> > ---
> >  arch/x86/platform/efi/efi_64.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
> > index a4695da..6cbf9e0 100644
> > --- a/arch/x86/platform/efi/efi_64.c
> > +++ b/arch/x86/platform/efi/efi_64.c
> > @@ -47,7 +47,7 @@
> >  #include <asm/pgalloc.h>
> >  
> >  /*
> > - * We allocate runtime services regions bottom-up, starting from -4G, i.e.
> > + * We allocate runtime services regions top-down, starting from -4G, i.e.
> 
> Baoquan, I think original bottom-up is right, it is just considering
> -68G as up, see the x86_64 mm.txt. We regard vmalloc as higher address
> although from mathematics view it is lower then positive addresses.

Thanks for reviewing!

I am not sure. Just in efi_map_region() it gets the starting va to map
'size' big of region by below code:
	efi_va -= size;

-4G and -68G just a trick which makes people understand easily, still we
think kernel text mapping region is in higher addr area then vmalloc. I
personnally think.

Thanks
Baoquan