[PATCH stable/v4.2.y] ARM: ux500: simplify secondary CPU boot

[Greg KH]

On Thu, Oct 22, 2015 at 03:56:08PM -0700, Kevin Hilman wrote:
> From: Linus Walleij <linus.walleij at linaro.org>
> 
> This removes a lot of ancient cruft from the Ux500 SMP boot.
> Instead of the pen grab/release, just point the ROM to
> secondary_boot() and start the second CPU there, then send
> the IPI.
> 
> Use our own SMP enable method. This enables us to remove the
> last static mapping and get both CPUs booting properly.
> 
> Tested this and it just works.
> 
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> Signed-off-by: Olof Johansson <olof at lixom.net>
> (cherry picked from commit c00def71efd919e8ae835a25f4f4c80a4b2d36d3)
> Cc: <stable at vger.kernel.org> # v4.2+
> Signed-off-by: Kevin Hilman <khilman at linaro.org>
> ---
> This patch was the 2nd in a 2-patch series.  Only the 1st patch made it
> into v4.2, but this one is also needed for booting on the ste-snowball.
> 
>  arch/arm/mach-ux500/Makefile     |   2 +-
>  arch/arm/mach-ux500/cpu-db8500.c |   1 -
>  arch/arm/mach-ux500/headsmp.S    |  37 -----------
>  arch/arm/mach-ux500/platsmp.c    | 132 ++++++++++++---------------------------
>  arch/arm/mach-ux500/setup.h      |   1 -
>  5 files changed, 40 insertions(+), 133 deletions(-)
>  delete mode 100644 arch/arm/mach-ux500/headsmp.S

This looks to me like a "new feature", is it a regression from something
that used to work in 4.1?

thanks,

greg k-h