Revert "Merge branch '2023-07-24-introduce-FF-A-suppport'"

This reverts commit d927d1a80843e1c3e2a3f0b8f6150790bef83da1, reversing
changes made to c07ad9520c6190070513016fdb495d4703a4a853.

These changes do not pass CI currently.

Signed-off-by: Tom Rini <trini@konsulko.com>

3 files changed, 0 insertions, 263 deletions

diff --git a/doc/arch/arm64.ffa.rst b/doc/arch/arm64.ffa.rst
deleted file mode 100644
index 325fb80346..0000000000
--- a/doc/arch/arm64.ffa.rst
+++ /dev/null
@@ -1,261 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0+
-
-Arm FF-A Support
-================
-
-Summary
--------
-
-FF-A stands for Firmware Framework for Arm A-profile processors.
-
-FF-A specifies interfaces that enable a pair of software execution environments aka partitions to
-communicate with each other. A partition could be a VM in the Normal or Secure world, an
-application in S-EL0, or a Trusted OS in S-EL1.
-
-The U-Boot FF-A support (the bus) implements the interfaces to communicate
-with partitions in the Secure world aka Secure partitions (SPs).
-
-The FF-A support specifically focuses on communicating with SPs that
-isolate portions of EFI runtime services that must run in a protected
-environment which is inaccessible by the Host OS or Hypervisor.
-Examples of such services are set/get variables.
-
-The FF-A support uses the SMC ABIs defined by the FF-A specification to:
-
-- Discover the presence of SPs of interest
-- Access an SP's service through communication protocols
-  e.g. EFI MM communication protocol
-
-At this stage of development only EFI boot-time services are supported.
-Runtime support will be added in future developments.
-
-The U-Boot FF-A support provides the following parts:
-
-- A Uclass driver providing generic FF-A methods.
-- An Arm FF-A device driver providing Arm-specific methods and reusing the Uclass methods.
-- A sandbox emulator for Arm FF-A, emulates the FF-A side of the Secure World and provides
-  FF-A ABIs inspection methods.
-- An FF-A sandbox device driver for FF-A communication with the emulated Secure World.
-  The driver leverages the FF-A Uclass to establish FF-A communication.
-- Sandbox FF-A test cases.
-
-FF-A and SMC specifications
--------------------------------------------
-
-The current implementation of the U-Boot FF-A support relies on
-`FF-A v1.0 specification`_ and uses SMC32 calling convention which
-means using the first 32-bit data of the Xn registers.
-
-At this stage we only need the FF-A v1.0 features.
-
-The FF-A support has been tested with OP-TEE which supports SMC32 calling
-convention.
-
-Hypervisors are supported if they are configured to trap SMC calls.
-
-The FF-A support uses 64-bit registers as per `SMC Calling Convention v1.2 specification`_.
-
-Supported hardware
---------------------------------
-
-Aarch64 plaforms
-
-Configuration
-----------------------
-
-CONFIG_ARM_FFA_TRANSPORT
-    Enables the FF-A support. Turn this on if you want to use FF-A
-    communication.
-    When using an Arm 64-bit platform, the Arm FF-A driver will be used.
-    When using sandbox, the sandbox FF-A emulator and FF-A sandbox driver will be used.
-
-FF-A ABIs under the hood
----------------------------------------
-
-Invoking an FF-A ABI involves providing to the secure world/hypervisor the
-expected arguments from the ABI.
-
-On an Arm 64-bit platform, the ABI arguments are stored in x0 to x7 registers.
-Then, an SMC instruction is executed.
-
-At the secure side level or hypervisor the ABI is handled at a higher exception
-level and the arguments are read and processed.
-
-The response is put back through x0 to x7 registers and control is given back
-to the U-Boot Arm FF-A driver (non-secure world).
-
-The driver reads the response and processes it accordingly.
-
-This methodology applies to all the FF-A ABIs.
-
-FF-A bus discovery on Arm 64-bit platforms
----------------------------------------------
-
-When CONFIG_ARM_FFA_TRANSPORT is enabled, the FF-A bus is considered as
-an architecture feature and discovered using ARM_SMCCC_FEATURES mechanism.
-This discovery mechanism is performed by the PSCI driver.
-
-The PSCI driver comes with a PSCI device tree node which is the root node for all
-architecture features including FF-A bus.
-
-::
-
-   => dm tree
-
-    Class     Index  Probed  Driver                Name
-   -----------------------------------------------------------
-    firmware      0  [ + ]   psci                      |-- psci
-    ffa                   0  [   ]   arm_ffa               |   `-- arm_ffa
-
-The PSCI driver is bound to the PSCI device and when probed it tries to discover
-the architecture features by calling a callback the features drivers provide.
-
-In case of FF-A, the callback is arm_ffa_is_supported() which tries to discover the
-FF-A framework by querying the FF-A framework version from secure world using
-FFA_VERSION ABI. When discovery is successful, the ARM_SMCCC_FEATURES
-mechanism creates a U-Boot device for the FF-A bus and binds the Arm FF-A driver
-with the device using device_bind_driver().
-
-At this stage the FF-A bus is registered with the DM and can be interacted with using
-the DM APIs.
-
-Clients are able to probe then use the FF-A bus by calling uclass_first_device().
-Please refer to the armffa command implementation as an example of how to probe
-and interact with the FF-A bus.
-
-When calling uclass_first_device(), the FF-A driver is probed and ends up calling
-ffa_do_probe() provided by the Uclass which does the following:
-
-    - saving the FF-A framework version in uc_priv
-    - querying from secure world the u-boot endpoint ID
-    - querying from secure world the supported features of FFA_RXTX_MAP
-    - mapping the RX/TX buffers
-    - querying from secure world all the partitions information
-
-When one of the above actions fails, probing fails and the driver stays not active
-and can be probed again if needed.
-
-Requirements for clients
--------------------------------------
-
-When using the FF-A bus with EFI, clients must query the SPs they are looking for
-during EFI boot-time mode using the service UUID.
-
-The RX/TX buffers are only available at EFI boot-time. Querying partitions is
-done at boot time and data is cached for future use.
-
-RX/TX buffers should be unmapped before EFI runtime mode starts.
-The driver provides a bus operation for that called ffa_rxtx_unmap().
-
-The user should call ffa_rxtx_unmap() to unmap the RX/TX buffers when required
-(e.g: at efi_exit_boot_services()).
-
-The Linux kernel allocates its own RX/TX buffers. To be able to register these kernel buffers
-with secure world, the U-Boot's RX/TX buffers should be unmapped before EFI runtime starts.
-
-When invoking FF-A direct messaging, clients should specify which ABI protocol
-they want to use (32-bit vs 64-bit). Selecting the protocol means using
-the 32-bit or 64-bit version of FFA_MSG_SEND_DIRECT_{REQ, RESP}.
-The calling convention between U-Boot and the secure world stays the same: SMC32.
-
-Requirements for user drivers
--------------------------------------
-
-Users who want to implement their custom FF-A device driver while reusing the FF-A Uclass can do so
-by implementing their own invoke_ffa_fn() in the user driver.
-
-The bus driver layer
-------------------------------
-
-FF-A support comes on top of the SMCCC layer and is implemented by the FF-A Uclass drivers/firmware/arm-ffa/arm-ffa-uclass.c
-
-The following features are provided:
-
-- Support for the 32-bit version of the following ABIs:
-
-    - FFA_VERSION
-    - FFA_ID_GET
-    - FFA_FEATURES
-    - FFA_PARTITION_INFO_GET
-    - FFA_RXTX_UNMAP
-    - FFA_RX_RELEASE
-    - FFA_RUN
-    - FFA_ERROR
-    - FFA_SUCCESS
-    - FFA_INTERRUPT
-    - FFA_MSG_SEND_DIRECT_REQ
-    - FFA_MSG_SEND_DIRECT_RESP
-
-- Support for the 64-bit version of the following ABIs:
-
-    - FFA_RXTX_MAP
-    - FFA_MSG_SEND_DIRECT_REQ
-    - FFA_MSG_SEND_DIRECT_RESP
-
-- Processing the received data from the secure world/hypervisor and caching it
-
-- Hiding from upper layers the FF-A protocol and registers details. Upper
-  layers focus on exchanged data, FF-A support takes care of how to transport
-  that to the secure world/hypervisor using FF-A
-
-- FF-A support provides driver operations to be used by upper layers:
-
-    - ffa_partition_info_get
-    - ffa_sync_send_receive
-    - ffa_rxtx_unmap
-
-- FF-A bus discovery makes sure FF-A framework is responsive and compatible
-  with the driver
-
-- FF-A bus can be compiled and used without EFI
-
-Relationship between the sandbox emulator and the FF-A device
----------------------------------------------------------------
-
-::
-
-   => dm tree
-
-    Class     Index  Probed  Driver                Name
-   -----------------------------------------------------------
-   ffa_emul      0  [ + ]   sandbox_ffa_emul      `-- arm-ffa-emul
-    ffa                  0  [    ]   sandbox_arm_ffa               `-- sandbox-arm-ffa
-
-The armffa command
------------------------------------
-
-armffa is a command showcasing how to use the FF-A bus and how to invoke the driver operations.
-
-Please refer the command documentation at :doc:`../usage/cmd/armffa`
-
-Example of boot logs with FF-A enabled
---------------------------------------
-
-For example, when using FF-A with Corstone-1000 the logs are as follows:
-
-::
-
-   U-Boot 2023.01 (May 10 2023 - 11:08:07 +0000) corstone1000 aarch64
-
-   DRAM:  2 GiB
-   Arm FF-A framework discovery
-   FF-A driver 1.0
-   FF-A framework 1.0
-   FF-A versions are compatible
-   ...
-   FF-A driver 1.0
-   FF-A framework 1.0
-   FF-A versions are compatible
-   EFI: MM partition ID 0x8003
-   ...
-   EFI stub: Booting Linux Kernel...
-   ...
-   Linux version 6.1.9-yocto-standard (oe-user@oe-host) (aarch64-poky-linux-musl-gcc (GCC) 12.2.0, GNU ld (GNU Binutils) 2.40.202301193
-   Machine model: ARM Corstone1000 FPGA MPS3 board
-
-Contributors
-------------
-   * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
-
-.. _`FF-A v1.0 specification`: https://documentation-service.arm.com/static/5fb7e8a6ca04df4095c1d65e
-.. _`SMC Calling Convention v1.2 specification`: https://documentation-service.arm.com/static/5f8edaeff86e16515cdbe4c6
diff --git a/doc/arch/index.rst b/doc/arch/index.rst
index 2f916f4026..b8da4b8c8e 100644
--- a/doc/arch/index.rst
+++ b/doc/arch/index.rst
@@ -8,7 +8,6 @@ Architecture-specific doc
 
    arc
    arm64
-   arm64.ffa
    m68k
    mips
    nios2
diff --git a/doc/arch/sandbox/sandbox.rst b/doc/arch/sandbox/sandbox.rst
index a3631de749..77ca6bc4cc 100644
--- a/doc/arch/sandbox/sandbox.rst
+++ b/doc/arch/sandbox/sandbox.rst
@@ -200,7 +200,6 @@ Supported Drivers
 
 U-Boot sandbox supports these emulations:
 
-- Arm FF-A
 - Block devices
 - Chrome OS EC
 - GPIO