ARM: HYP/non-sec: move switch to non-sec to the last boot phase

Having the switch to non-secure in the "prep" phase is causing
all kind of troubles, as that stage can be called multiple times.

Instead, move the switch to non-secure to the last possible phase,
when there is no turning back anymore.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: HYP/non-sec: add a barrier after setting SCR.NS==1

A CP15 instruction execution can be reordered, requiring an
isb to be sure it is executed in program order.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: non-sec: reset CNTVOFF to zero

Before switching to non-secure, make sure that CNTVOFF is set
to zero on all CPUs. Otherwise, kernel running in non-secure
without HYP enabled (hence using virtual timers) may observe
timers that are not synchronized, effectively seeing time
going backward...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: add missing HYP mode constant

In order to be able to use the various mode constants (far more
readable than random hex values), add the missing HYP and A
values.

Also update arm/lib/interrupts.c to display HYP instead of an
unknown value.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: HYP/non-sec: add separate section for secure code

In anticipation of refactoring the HYP/non-secure code to run
from secure RAM, add a new linker section that will contain that
code.

Nothing is using it just yet.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: HYP/non-sec: allow relocation to secure RAM

The current non-sec switching code suffers from one major issue:
it cannot run in secure RAM, as a large part of u-boot still needs
to be run while we're switched to non-secure.

This patch reworks the whole HYP/non-secure strategy by:
- making sure the secure code is the *last* thing u-boot executes
  before entering the payload
- performing an exception return from secure mode directly into
  the payload
- allowing the code to be dynamically relocated to secure RAM
  before switching to non-secure.

This involves quite a bit of horrible code, specially as u-boot
relocation is quite primitive.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: HYP/non-sec: add generic ARMv7 PSCI code

Implement core support for PSCI. As this is generic code, it doesn't
implement anything really useful (all the functions are returning
Not Implemented).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: HYP/non-sec: add the option for a second-stage monitor

Allow the switch to a second stage secure monitor just before
switching to non-secure.

This allows a resident piece of firmware to be active once the
kernel has been entered (the u-boot monitor is dead anyway,
its pages being reused).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: convert arch_fixup_memory_node to a generic FDT fixup function

Some architecture needs extra device tree setup. Instead of adding
yet another hook, convert arch_fixup_memory_node to be a generic
FDT fixup function.

[maz: collapsed 3 patches into one, rewrote commit message]

Signed-off-by: Ma Haijun <mahaijuns@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
ARM: HYP/non-sec/PSCI: emit DT nodes

Generate the PSCI node in the device tree.

Also add a reserve section for the "secure" code that lives in
in normal RAM, so that the kernel knows it'd better not trip on
it.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
sunxi: HYP/non-sec: add sun7i PSCI backend

So far, only supporting the CPU_ON method.
Other functions can be added later.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
sunxi: HYP/non-sec: configure CNTFRQ on all CPUs

CNTFRQ needs to be properly configured on all CPUs. Otherwise,
virtual machines hoping to find valuable information on secondary
CPUs will be disapointed...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>