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

[Kevin Hilman]

On Thu, Oct 22, 2015 at 5:17 PM, Greg KH <greg at kroah.com> wrote:
> 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?

I guess Linus W. will have to explain better, but I'll try...

it's the 2nd part of a 2-part fix that was submitted for v4.2, but
only the 1st part made it in because it was late for the merge window.

Kevin