Re: [PATCH v1 RESEND 2/2] x86/efi: Clean up a minor mistake in code comment

[Baoquan He]

On 03/24/17 at 08:57am, Ard Biesheuvel wrote:
> On 23 March 2017 at 03:27, Baoquan He <bhe@xxxxxxxxxx> wrote:
> > EFI allocate runtime services regions from EFI_VA_START, -4G, down
> > to -64G, EFI_VA_END.
> 
> OK, so is the size of the region 60 GB or 64 GB? This suggests 60 GB,
> but the comment you update suggests 64 GB.

Ah, sorry, here it should be -68G. The reserved EFI region is [-68G,
-4G), amount is 64G.

Thanks, will repost with updated log.

> 
> > The mechanism was introduced in
> > commit d2f7cbe7b26a7 ("x86/efi: Runtime services virtual mapping").
> >
> > Clean it up to avoid confusion.
> >
> > Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> > Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
> > Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> > Cc: Borislav Petkov <bp@xxxxxxxxx>
> > Cc: x86@xxxxxxxxxx
> > Cc: linux-efi@xxxxxxxxxxxxxxx
> > ---
> >  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.
> >   * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
> >   */
> >  static u64 efi_va = EFI_VA_START;
> > --
> > 2.5.5
> >