It turns out that the logical CPU mapping is useful even when !CONFIG_SMP
for manipulation of devices like interrupt and power controllers when
running a UP kernel on a CPU other than 0. This can happen when kexecing
a UP image from an SMP kernel.

In the future, multi-cluster systems running AMP configurations will
require something similar for mapping cluster IDs, so it makes sense to
decouple this logic in preparation for this support.
Acked-by: NYang Bai <hamo.by@gmail.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Reported-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch uses the new cpu_logical_map() macro for converting logical
CPU numbers into physical numbers when dealing with the pen_release
variable in the SMP boot and CPU hotplug paths.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

platform_cpu_die() is entered from the CPU's own idle thread, which
can not be migrated to other CPUs.  Moreover, the 'cpu' argument
comes from the thread info, which will always be the 'current'
CPU.  So remove this useless bug check.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We always need to wait for the dying CPU to reach a safe state before
taking it down, irrespective of the requirements of the platform.
Move the completion code into the ARM SMP hotplug code rather than
having each platform re-implement this.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NSundar Iyer <sundar.iyer@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>