Re: [PATCH 2/2] ppc64: Add a flag to tell the kernel it's booting from kexec

[Michael Ellerman <mpe@ellerman.id.au>]

On Mon, 2015-08-17 at 22:30 -0500, Scott Wood wrote:
> On Tue, 2015-08-18 at 12:51 +1000, Michael Ellerman wrote:
> > On Mon, 2015-08-17 at 13:59 -0500, Scott Wood wrote:
> > > On Sat, 2015-07-18 at 14:57 -0500, Scott Wood wrote:
> > > > It needs to know this because the SMP release mechanism for Freescale
> > > > book3e is different from when booting with normal hardware.  In theory
> > > > we could simulate the normal spin table mechanism, but not (easily) at
> > > > the addresses U-Boot put in the device tree -- so there'd need to be
> > > > even more communication between the kernel and kexec to set that up.
> > > > Since there's already a similar flag being set (for kdump only), this
> > > > seemed like a reasonable approach.
> > > > 
> > > > Signed-off-by: Scott Wood <scottwood@freescale.com>
> > > > ---
> > > >  kexec/arch/ppc64/kexec-elf-ppc64.c | 11 ++++++++++-
> > > >  kexec/arch/ppc64/kexec-ppc64.h     |  2 ++
> > > >  purgatory/arch/ppc64/v2wrap.S      | 11 +++++++++++
> > > >  3 files changed, 23 insertions(+), 1 deletion(-)
> > > 
> > > Any comment on these two patches?
> > 
> > We should probably reserve 0x58 in the kernel's head_64.S too?
> 
> That's done in http://patchwork.ozlabs.org/patch/497417/

Right, sorry should have reviewed those :)

> Or do you mean that you want the kernel change to go in before the userspace 
> change?

No I'm not bothered about the ordering really.

cheers