[PATCH 3/4] kexec-tools: mips: Use proper page_offset for OCTEON CPUs.

[Simon Horman]

On Mon, Oct 16, 2017 at 09:05:22AM -0700, David Daney wrote:
> On 10/15/2017 11:56 PM, Simon Horman wrote:
> > On Thu, Oct 12, 2017 at 02:02:27PM -0700, David Daney wrote:
> > > The OCTEON family of MIPS64 CPUs uses a PAGE_OFFSET of
> > > 0x8000000000000000ULL, which is differs from other CPUs.
> > > 
> > > Scan /proc/cpuinfo to see if the current system is "Octeon", if so,
> > > patch the page_offset so that usable kdump core files are produced.
> > > 
> > > Signed-off-by: David Daney <david.daney at cavium.com>
> > 
> > Is it possible to read this offset from the system rather than
> > checking for an Octeon CPU? It seems that such an approach, if possible,
> > would be somewhat more general.
> > 
> 
> Before implementing this scanning of /proc/cpuinfo, I thought long and hard
> about this, and couldn't think of how the PAGE_OFFSET could be derived from
> information available in userspace.
> 
> Ralf (MIPS maintainer) may have an idea, but these address bits don't show
> up in /proc/kallsyms or any other file in /proc or /sys that I am aware of.

Thanks for the explanation. I've applied this patch pending any further
progress in this area.