pmdomain: arm_scmi: Move Kconfig options to the pmdomain subsystem

The Kconfig options belongs closer to the corresponding implementations,
hence let's move them from the firmware to the pmdomain subsystem.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20231123120847.2825444-1-sudeep.holla@arm.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

pmdomain: arm: Add the SCMI performance domain

To enable support for performance scaling (DVFS) for generic devices with
the SCMI performance protocol, let's add an SCMI performance domain. This
is being modelled as a genpd provider, with support for performance scaling
through genpd's ->set_performance_state() callback.

Note that, this adds the initial support that allows consumer drivers for
attached devices, to vote for a new performance state via calling the
dev_pm_genpd_set_performance_state(). However, this should be avoided as
it's in most cases preferred to use the OPP library to vote for a new OPP
instead. The support using the OPP library isn't part of this change, but
needs to be implemented from subsequent changes.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20230919121605.7304-1-ulf.hansson@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add the raw mode co-existence support

When the raw support is enabled and configured in co-existence mode the
normal SCMI drivers are allowed to register with the SCMI core and
operate as usual alongside the raw operations.

SCMI normal and raw messages will be kept segregated from each other,
but only at the transaction level. Any further possible interference at
the protocol layer will have instead to be handled by the user to attain
reliable results while using the raw transactions.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-17-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add core raw transmission support

Add SCMI raw mode support which exposes a userspace interface to allow for
bare SCMI command injection and snooping from userspace.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-13-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Populate a common SCMI debugfs root

Create a common SCMI debugfs root directory and populate it with some
common SCMI data for each discovered SCMI platform instance if SCMI
debugfs is needed by any configured SCMI facility.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-11-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add SCMI System Power Control driver

Add an SCMI System Power control driver to handle platform's requests
carried by SYSTEM_POWER_STATE_NOTIFIER notifications: such platform
requested system-wide power state transitions are handled accordingly,
gracefully or forcefully, depending on the notifications' message flags.

Graceful requests are relayed to userspace using the same Kernel API used
to handle ACPI Shutdown bus events.

Link: https://lore.kernel.org/r/20220704101933.2981635-5-cristian.marussi@arm.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Support optee shared memory in the optee transport

Add support for TEE shared memory in optee scmi transport. When using
tee shared memory, scmi optee transport manages SCMI messages using
msg protocol(from msg.c) in shared memory, whereas smt(from shmem.c)
protocol is used with static IOMEM based shared buffers.

Link: https://lore.kernel.org/r/20220425085127.2009-1-etienne.carriere@linaro.org
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add atomic mode support to virtio transport

Add support for .mark_txdone and .poll_done transport operations to SCMI
VirtIO transport as pre-requisites to enable atomic operations.

Add a Kernel configuration option to enable SCMI VirtIO transport polling
and atomic mode for selected SCMI transactions while leaving it default
disabled.

Link: https://lore.kernel.org/r/20220217131234.50328-4-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Igor Skalkin <igor.skalkin@opensynergy.com>
Cc: Peter Hilber <peter.hilber@opensynergy.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add atomic mode support to smc transport

Add a Kernel configuration option to enable SCMI SMC transport atomic
mode operation for selected SCMI transactions and leave it as default
disabled.

Substitute mutex usages with busy-waiting and declare smc transport as
.atomic_enabled if such Kernel configuration option is enabled.

Link: https://lore.kernel.org/r/20211220195646.44498-8-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Make virtio Version_1 compliance optional

Introduce a compilation option to disable strict enforcement of compliance
against VirtIO Version_1 backends, so as to allow to support also Legacy
VirtIO devices implementations.

Link: https://lore.kernel.org/r/20211115102910.7639-1-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add optee transport

Add a new transport channel to the SCMI firmware interface driver for
SCMI message exchange based on optee transport channel. The optee
transport is realized by connecting and invoking OP-TEE SCMI service
interface PTA.

Optee transport support (CONFIG_ARM_SCMI_TRANSPORT_OPTEE) is default
enabled when optee driver (CONFIG_OPTEE) is enabled. Effective optee
transport is setup upon OP-TEE SCMI service discovery at optee
device initialization. For this SCMI UUID is registered to the optee
bus for probing. This is done from the link_supplier operator of the
SCMI optee transport.

The optee transport can use a statically defined shared memory in
which case SCMI device tree node defines it using an "arm,scmi-shmem"
compatible phandle through property shmem. Alternatively, optee transport
allocates the shared memory buffer from the optee driver when no shmem
property is defined.

The protocol used to exchange SCMI message over that shared memory is
negotiated between optee transport driver and the OP-TEE service through
capabilities exchange.

OP-TEE SCMI service is integrated in OP-TEE since its release tag 3.13.0.
The service interface is published in [1].

Link: [1] https://github.com/OP-TEE/optee_os/blob/3.13.0/lib/libutee/include/pta_scmi_client.h
Link: https://lore.kernel.org/r/20211028140009.23331-2-etienne.carriere@linaro.org
Cc: Cristian Marussi <cristian.marussi@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Fix virtio transport Kconfig dependency

ARM_SCMI_TRANSPORT_VIRTIO is a 'bool' Kconfig used to include support for
the SCMI virtio transport inside the core SCMI stack; a bare transport
dependency attached here to this option, though, cannot be properly
propagated to the parent ARM_SCMI_PROTOCOL option and, as a result, it is
currently possible to configure a Kernel where SCMI core is builtin
and includes support for virtio while VirtIO core is =m.
This allowed combination breaks linking:

ARM_SCMI_PROTOCOL=y
ARM_SCMI_TRANSPORT_VIRTIO=y
VIRTIO=m

Bind the dependency in ARM_SCMI_TRANSPORT_VIRTIO to the chosen kind of
compilation of ARM_SCMI_PROTOCOL.

Link: https://lore.kernel.org/r/20210816141609.41751-1-cristian.marussi@arm.com
Fixes: 46abe13b5e3d ("firmware: arm_scmi: Add virtio transport")
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Arnd Bergmann <arnd@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add virtio transport

This transport enables communications with an SCMI platform through virtio;
the SCMI platform will be represented by a virtio device.

Implement an SCMI virtio driver according to the virtio SCMI device spec
[1]. Virtio device id 32 has been reserved for the SCMI device [2].

The virtio transport has one Tx channel (virtio cmdq, A2P channel) and
at most one Rx channel (virtio eventq, P2A channel).

The following feature bit defined in [1] is not implemented:
VIRTIO_SCMI_F_SHARED_MEMORY.

The number of messages which can be pending simultaneously is restricted
according to the virtqueue capacity negotiated at probing time.

As soon as Rx channel message buffers are allocated or have been read
out by the arm-scmi driver, feed them back to the virtio device.

Since some virtio devices may not have the short response time exhibited
by SCMI platforms using other transports, set a generous response
timeout.

SCMI polling mode is not supported by this virtio transport since deemed
meaningless: polling mode operation is offered by the SCMI core to those
transports that could not provide a completion interrupt on the TX path,
which is never the case for virtio whose core callbacks can easily call
into core scmi_rx_callback upon messages reception.

[1] https://github.com/oasis-tcs/virtio-spec/blob/master/virtio-scmi.tex
[2] https://www.oasis-open.org/committees/ballot.php?id=3496

Link: https://lore.kernel.org/r/20210803131024.40280-16-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
Co-developed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
[ Peter: Adapted patch for submission to upstream. ]
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: simplified driver logic, changed link_supplier and channel
available/setup logic, removed dummy callbacks ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Add message passing abstractions for transports

Add abstractions for future transports using message passing, such as
virtio. Derive the abstractions from the shared memory abstractions.

Abstract the transport SDU through the opaque struct scmi_msg_payld.
Also enable the transport to determine all other required information
about the transport SDU.

Link: https://lore.kernel.org/r/20210803131024.40280-12-cristian.marussi@arm.com
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: Adapted to new SCMI Kconfig layout, updated Copyrights ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Make shmem support optional for transports

Upcoming new SCMI transports won't need any kind of shared memory support.
Compile shmem.c only if a shmem based transport is selected.

Link: https://lore.kernel.org/r/20210803131024.40280-10-cristian.marussi@arm.com
Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
[ Peter: Adapted patch for submission to upstream. ]
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: Adapted patch/commit_msg to new SCMI Kconfig layout ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Make SCMI transports configurable

Add configuration options to be able to select which SCMI transports have
to be compiled into the SCMI stack.

Mailbox and SMC are by default enabled if their related dependencies are
satisfied.

While doing that move all SCMI related config options in their own
dedicated submenu.

Link: https://lore.kernel.org/r/20210803131024.40280-9-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>