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In order to keep SCP firmware as optional, the original, limited native
PSCI implementation was kept around as a fallback. This turned out to be
a good decision, as some newer SoCs omit the ARISC, and thus cannot run
SCP firmware.

However, keeping the two implementations in one file makes things
unnecessarily messy. First, it is difficult to compile out the
SCPI-based implementation where it is not applicable. Second the check
is done in each callback, while scpi_available is only updated at boot.
This makes the individual callbacks unnecessarily complicated.

It is cleaner to provide two entirely separate implementations in two
separate files. The native implementation does not support any kind of
CPU suspend, so its callbacks are greatly simplified. One function,
sunxi_validate_ns_entrypoint, is shared between the two implementations.

Finally, the logic for choosing between implementations is kept in a
third file, to provide for platforms where only one implementation is
applicable and the other is compiled out.

Change-Id: I4914f07d8e693dbce218e0e2394bef15c42945f8
Signed-off-by: Samuel Holland <samuel@sholland.org>

- When the SCPI shutdown/reset command returns success, the SCP is
  still waiting for the CPU to enter WFI. Do that.
- Peform board-level poweroff before CPU poweroff. If there is a PMIC
  available, it will turn everything off including the CPUs, so doing
  CPU poweroff first is a waste of cycles.
- During poweroff, attempt to turn off the local CPU using the ARISC.
  This should use slightly less power than just an infinite WFI.
- Drop the WFI in the reset failure path. The panic will hang anyway.

Change-Id: I897efecb3fe4e77a56041b97dd273156ec51ef8e
Signed-off-by: Samuel Holland <samuel@sholland.org>

When operating on the local cpu, sunxi_cpu_power_off_self() only "arms"
the ARISC to perform the power-off process; the SCP waits for the CPU to
enter WFI before acutally powering it off. Since this matches the
expected split between .pwr_domain_off and .pwr_domain_pwr_down_wfi, we
can move the sunxi_cpu_power_off_self() call to sunxi_pwr_domain_off().
Since that change makes sunxi_pwr_down_wfi() equivalent to the default
implementation, the callback is no longer needed.

Change-Id: I7d65f66c550d1c69fa5e9945affd7a25b3d3ef42
Signed-off-by: Samuel Holland <samuel@sholland.org>

Currently, sunxi_cpu_off() has two separate code paths: one for the
local CPU, and one for other CPUs. Let's split them in to two functions.
This actually simplifies things, because all callers either operate on
the local CPU only (sunxi_pwr_down_wfi()) or other CPUs only
(sunxi_cpu_power_off_others()). This avoids needing a second MPIDR read
to choose the appropriate code path.

Change-Id: I55de85025235cc95466bfa106831fc4c2368f527
Signed-off-by: Samuel Holland <samuel@sholland.org>

Checking the exceptional case and letting the success case fall through
is not only more idiomatic, but it also allows adding more exceptional
cases in the future, such as a check for overlapping secure DRAM.

Change-Id: I720441a6a8853fd7f211ebe851f14d921a6db03d
Signed-off-by: Samuel Holland <samuel@sholland.org>

This duplicated the logic in psci_validate_mpidr() which was already
called from psci_cpu_on().

Change-Id: I96ee92f1ce3e9cc2985b4e229ba86ebd27b79915
Signed-off-by: Samuel Holland <samuel@sholland.org>

This optional PSCI function was only implemented when SCPI was
available. However, the underlying SCPI function is not able to fulfill
the necessary contract. First, the SCPI protocol has no way to represent
HW_STANDBY at the CPU power level. Second, the SCPI implementation
maintains its own logical view of power states, and its implementation
of SCPI_CMD_GET_CSS_POWER_STATE does not actually query the hardware.
Thus it cannot provide "the physical view of power state", as required
for this function by the PSCI specification.

Since the function is optional, drop it.

Change-Id: I5f3a0810ac19ddeb3c0c5d35aeb09f09a0b80c1d
Signed-off-by: Samuel Holland <samuel@sholland.org>

If an SCP firmware is present and able to communicate via SCPI, then use
that to implement CPU and system power state transitions, including CPU
hotplug and system suspend. Otherwise, fall back to the existing CPU
power control implementation.

The last 16 KiB of SRAM A2 are reserved for the SCP firmware, and the
SCPI shared memory is at the very end of this region (and therefore the
end of SRAM A2). BL31 continues to start at the beginning of SRAM A2
(not counting the ARISC exception vector area) and fills up to the
beginning of the SCP firmware.

Because the SCP firmware is not loaded adjacent to the ARISC exception
vector area, the jump instructions used for exception handling cannot be
included in the SCP firmware image, and must be initialized here before
turning on the SCP.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I37b9b9636f94d4125230423726f3ac5e9cdb551c

The action of last resort isn't going to change between SoCs. This moves
that code back to the PSCI implementation, where it more obviously
matches the code in sunxi_system_reset().

The two error messages say essentially the same thing anyway.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I62ac35fdb5ed78a016e9b18281416f1dcea38a4a

Some Allwinner H6 has a broken watchdog that doesn't
make the soc reboot.

Use the R_WATCHDOG instead.
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Change-Id: Ie95cc30a80ed517b60b30d6bc2e655a1b53f18ba

Convert them to take an mpidr instead of a (cluster, core) pair. This
simplifies all of the call sites, and actually makes the functions a bit
smaller.
Signed-off-by: Samuel Holland <samuel@sholland.org>

Enforce full include path for includes. Deprecate old paths.

The following folders inside include/lib have been left unchanged:

- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}

The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).

For example, this patch had to be created because two headers were
called the same way: e0ea0928 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3 ("drivers: add tzc380 support").

This problem was introduced in commit 4ecca339

 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.

Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.

Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

PSCI requires a core to turn itself off, which we can't do properly by
just executing an algorithm on that very core. As a consequence we just
put a core into WFI on CPU_OFF right now.
To fix this let's task the "arisc" management processor (an OpenRISC
core) with that task of asserting reset and turning off the core's power
domain. We use a handcrafted sequence of OpenRISC instructions to
achieve this, and hand this data over to the new sunxi_execute_arisc_code()
routine.
The commented source code for this routine is provided in a separate file,
but the ATF code contains the already encoded instructions as data.
The H6 uses the same algorithm, but differs in the MMIO addresses, so
provide a SoC (family) specific copy of that code.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

So far we have a sunxi_private.h header file in the common code directory.
This holds the prototypes of various functions we share in *common*
code. However we will need some of those in the platform specific code
parts as well, and want to introduce new functions shared across the
whole platform port.

So move the sunxi_private.h file into the common/include directory, so
that it becomes visible to all parts of the platform code.
Fix up the existing #includes and add missing ones, also add the
sunxi_read_soc_id() prototype here.

This will be used in follow up patches.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

The AXP805 PMIC used with H6 is capable of shutting down the system.

Add support for using it to shut down the system power.

The original placeholder power off code is moved to A64 code, as it's
still TODO to implement PMIC operations for A64.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>

The DRAM controller supports up to 4GB of DRAM, and there are actually
boards out there where we can use at least 3GB of this.

Relax the PSCI entry point check, to be not restricted to 2GB of DRAM.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

The reset vector entry point is preserved across CPU resets, so it only
needs to be set once at boot.

Hotplugged CPUs are not actually powered down, but are put in a wfi with
the GIC disconnected.

With this commit, Linux is able to enable, hotplug and use all four CPUs.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

sun50i_cpu_on will be used by the PSCI implementation to initialize
secondary cores for SMP. Unfortunately, sun50i_cpu_off is not usable by
PSCI directly, because it is not possible for a CPU to use this function
to power itself down. Power cannot be shut off until the outputs are
clamped, and MMIO does not work once the outputs are clamped.

But at least CPU0 can shutdown the other cores early in the BL31 boot
process and before shutting down the system.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

This platform supports Allwinner's SoCs with ARMv8 cores. So far they
all sport a single cluster of Cortex-A53 cores.

"sunxi" is the original code name used for this platform, and since it
appears in the Linux kernel and in U-Boot as well, we use it here as a
short file name prefix and for identifiers.

This port includes BL31 support only. U-Boot's SPL takes the role of the
primary loader, also doing the DRAM initialization. It then loads the
rest of the firmware, namely ATF and U-Boot (BL33), then hands execution
over to ATF.

This commit includes the basic platform code shared across all SoCs.
There is no platform.mk yet.

[Andre: moved files into proper directories, supported RESET_TO_BL31,
	various clean ups and simplifications ]
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>