[PATCH v16 04/10] arm_ffa: introduce Arm FF-A support

Ilias Apalodimas ilias.apalodimas at linaro.org
Thu Jul 27 11:56:50 CEST 2023


On Wed, Jul 26, 2023 at 10:44:57AM +0100, Abdellatif El Khlifi wrote:
> Add Arm FF-A support implementing Arm Firmware Framework for Armv8-A v1.0
> 
> The Firmware Framework for Arm A-profile processors (FF-A v1.0) [1]
> describes interfaces (ABIs) that standardize communication
> between the Secure World and Normal World leveraging TrustZone
> technology.
> 
> This driver uses 64-bit registers as per SMCCCv1.2 spec and comes
> on top of the SMCCC layer. The driver provides the FF-A ABIs needed for
> querying the FF-A framework from the secure world.
> 
> The driver uses SMC32 calling convention which means using the first
> 32-bit data of the Xn registers.
> 
> All supported ABIs come with their 32-bit version except FFA_RXTX_MAP
> which has 64-bit version supported.
> 
> Both 32-bit and 64-bit direct messaging are supported which allows both
> 32-bit and 64-bit clients to use the FF-A bus.
> 
> FF-A is a discoverable bus and similar to architecture features.
> FF-A bus is discovered using ARM_SMCCC_FEATURES mechanism performed
> by the PSCI driver.
> 
> Clients are able to probe then use the FF-A bus by calling the DM class
> searching APIs (e.g: uclass_first_device).
> 
> The Secure World is considered as one entity to communicate with
> using the FF-A bus. FF-A communication is handled by one device and
> one instance (the bus). This FF-A driver takes care of all the
> interactions between Normal world and Secure World.
> 
> The driver exports its operations to be used by upper layers.
> 
> Exported operations:
> 
> - ffa_partition_info_get
> - ffa_sync_send_receive
> - ffa_rxtx_unmap
> 
> Generic FF-A methods are implemented in the Uclass (arm-ffa-uclass.c).
> Arm specific methods are implemented in the Arm driver (arm-ffa.c).
> 
> For more details please refer to the driver documentation [2].
> 
> [1]: https://developer.arm.com/documentation/den0077/latest/
> [2]: doc/arch/arm64.ffa.rst
> 
> Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> Cc: Jens Wiklander <jens.wiklander at linaro.org>
> Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> 
> ---
> 
> Changelog:
> ===============
> 
> v13:
> 
> * doc minor change: specify in the readme that the user
>    should call ffa_rxtx_unmap() driver operation to unmap
>    the RX/TX buffers on demand.
> 
> v12:
> 
> * remove dscvry_info
> * replace dscvry_info.invoke_ffa_fn() with a weak invoke_ffa_fn
>    (user drivers can override it)
> * improve FFA_PARTITION_INFO_GET implementation
>    (clients no longer need to calloc a buffer)
> * address nits
> 
> v11:
> 
> * move ffa_try_discovery() from the uclass to the Arm FF-A driver
> * rename ffa_try_discovery() to arm_ffa_discover()
> * pass dev as an argument of arm_ffa_discover()
> * add arm_ prefix to the Arm FF-A driver functions
> * add emul field in struct ffa_discovery_info
> * address nits
> 
> v10:
> 
> * provide the driver operations through the Uclass
> * move the generic FF-A methods to the Uclass
> * keep Arm specific methods in the Arm driver (arm-ffa.c)
> * rename core.c to arm-ffa.c
> * address nits
> 
> v9:
> 
> * integrate the FF-A bus discovery in the DM and use ARM_SMCCC_FEATURES for binding
> 
> v8:
> 
> * make ffa_get_partitions_info() second argument to be an SP count in both
>   modes
> * update ffa_bus_prvdata_get() to return a pointer rather than a pointer
>   address
> * remove packing from ffa_partition_info and ffa_send_direct_data structures
> * pass the FF-A bus device to the bus operations
> 
> v7:
> 
> * add support for 32-bit direct messaging
> * rename be_uuid_str_to_le_bin() to uuid_str_to_le_bin()
> * improve the declaration of error handling mapping
> * stating in doc/arch/arm64.ffa.rst that EFI runtime is not supported
> 
> v6:
> 
> * drop use of EFI runtime support (We decided with Linaro to add this later)
> * drop discovery from initcalls (discovery will be on demand by FF-A users)
> * set the alignment of the RX/TX buffers to the larger translation granule size
> * move FF-A RX/TX buffers unmapping at ExitBootServices() to a separate commit
> * update the documentation and move it to doc/arch/arm64.ffa.rst
> 
> v4:
> 
> * add doc/README.ffa.drv
> * moving the FF-A driver work to drivers/firmware/arm-ffa
> * use less #ifdefs in lib/efi_loader/efi_boottime.c and replace
>   #if defined by #if CONFIG_IS_ENABLED
> * improving error handling by mapping the FF-A errors to standard errors
>   and logs
> * replacing panics with an error log and returning an error code
> * improving features discovery in FFA_FEATURES by introducing
>   rxtx_min_pages private data field
> * add ffa_remove and ffa_unbind functions
> * improve how the driver behaves when bus discovery is done more than
>   once
> 
> v3:
> 
> * align the interfaces of the U-Boot FF-A driver with those in the linux
>   FF-A driver
> * remove the FF-A helper layer
> * make the U-Boot FF-A driver independent from EFI
> * provide an optional config that enables copying the driver data to EFI
>   runtime section at ExitBootServices service
> * use 64-bit version of FFA_RXTX_MAP, FFA_MSG_SEND_DIRECT_{REQ, RESP}
> 
> v2:
> 
> * make FF-A bus discoverable using device_{bind, probe} APIs
> * remove device tree support
> 
> v1:
> 
> * introduce FF-A bus driver with device tree support
> 
> MAINTAINERS                                   |    8 +
>  doc/arch/arm64.ffa.rst                        |  238 ++++
>  doc/arch/index.rst                            |    1 +
>  drivers/Makefile                              |    1 +
>  drivers/firmware/Kconfig                      |    1 +
>  drivers/firmware/arm-ffa/Kconfig              |   36 +
>  drivers/firmware/arm-ffa/Makefile             |    8 +
>  drivers/firmware/arm-ffa/arm-ffa-uclass.c     | 1065 +++++++++++++++++
>  drivers/firmware/arm-ffa/arm-ffa.c            |  104 ++
>  .../firmware/arm-ffa/sandbox_arm_ffa_priv.h   |   14 +
>  include/arm_ffa.h                             |  213 ++++
>  include/arm_ffa_priv.h                        |  246 ++++
>  include/dm/uclass-id.h                        |    6 +
>  13 files changed, 1941 insertions(+)
>  create mode 100644 doc/arch/arm64.ffa.rst
>  create mode 100644 drivers/firmware/arm-ffa/Kconfig
>  create mode 100644 drivers/firmware/arm-ffa/Makefile
>  create mode 100644 drivers/firmware/arm-ffa/arm-ffa-uclass.c
>  create mode 100644 drivers/firmware/arm-ffa/arm-ffa.c
>  create mode 100644 drivers/firmware/arm-ffa/sandbox_arm_ffa_priv.h
>  create mode 100644 include/arm_ffa.h
>  create mode 100644 include/arm_ffa_priv.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4324965d26..4fd5768de0 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -266,6 +266,14 @@ F:	drivers/net/cortina_ni.h
>  F:	drivers/net/phy/ca_phy.c
>  F:	configs/cortina_presidio-asic-pnand_defconfig
>  
> +ARM FF-A
> +M:	Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> +S:	Maintained
> +F:	doc/arch/arm64.ffa.rst
> +F:	drivers/firmware/arm-ffa/
> +F:	include/arm_ffa.h
> +F:	include/sandbox_arm_ffa.h
> +
>  ARM FREESCALE IMX
>  M:	Stefano Babic <sbabic at denx.de>
>  M:	Fabio Estevam <festevam at gmail.com>
> diff --git a/doc/arch/arm64.ffa.rst b/doc/arch/arm64.ffa.rst
> new file mode 100644
> index 0000000000..4f817f053c
> --- /dev/null
> +++ b/doc/arch/arm64.ffa.rst
> @@ -0,0 +1,238 @@
> +.. 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.
> +
> +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.
> +
> +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
> +
> +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 at 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 at 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 b8da4b8c8e..2f916f4026 100644
> --- a/doc/arch/index.rst
> +++ b/doc/arch/index.rst
> @@ -8,6 +8,7 @@ Architecture-specific doc
>  
>     arc
>     arm64
> +   arm64.ffa
>     m68k
>     mips
>     nios2
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 78dcf62f76..5044f45253 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -115,6 +115,7 @@ obj-y += iommu/
>  obj-y += smem/
>  obj-y += thermal/
>  obj-$(CONFIG_TEE) += tee/
> +obj-$(CONFIG_ARM_FFA_TRANSPORT) += firmware/arm-ffa/
>  obj-y += axi/
>  obj-y += ufs/
>  obj-$(CONFIG_W1) += w1/
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> index eae1c8ddc9..8789b1ea14 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -45,4 +45,5 @@ config ARM_SMCCC_FEATURES
>  	  the PSCI driver is always probed and binds dirvers registered to the Arm SMCCC
>  	  services if any and reported as supported by the SMCCC firmware.
>  
> +source "drivers/firmware/arm-ffa/Kconfig"
>  source "drivers/firmware/scmi/Kconfig"
> diff --git a/drivers/firmware/arm-ffa/Kconfig b/drivers/firmware/arm-ffa/Kconfig
> new file mode 100644
> index 0000000000..9200c8028b
> --- /dev/null
> +++ b/drivers/firmware/arm-ffa/Kconfig
> @@ -0,0 +1,36 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +config ARM_FFA_TRANSPORT
> +	bool "Enable Arm Firmware Framework for Armv8-A driver"
> +	depends on DM && ARM64
> +	select ARM_SMCCC
> +	select ARM_SMCCC_FEATURES
> +	select LIB_UUID
> +	select DEVRES
> +	help
> +	  The Firmware Framework for Arm A-profile processors (FF-A)
> +	  describes interfaces (ABIs) that standardize communication
> +	  between the Secure World and Normal World leveraging TrustZone
> +	  technology.
> +
> +	  The FF-A support in U-Boot is based on FF-A specification v1.0 and uses SMC32
> +	  calling convention.
> +
> +	  FF-A specification:
> +
> +	  https://developer.arm.com/documentation/den0077/a/?lang=en
> +
> +	  In U-Boot FF-A design, FF-A is considered as a discoverable bus.
> +	  FF-A bus is discovered using ARM_SMCCC_FEATURES mechanism performed
> +	  by the PSCI driver.
> +	  The Secure World is considered as one entity to communicate with
> +	  using the FF-A bus.
> +	  FF-A communication is handled by one device and one instance (the bus).
> +	  The FF-A support on U-Boot  takes care of all the interactions between Normal
> +	  world and Secure World.
> +
> +	  Generic FF-A methods are implemented in the Uclass (arm-ffa-uclass.c).
> +	  Arm specific methods are implemented in the Arm driver (arm-ffa.c).
> +
> +	  For more details about the FF-A support, please refer to doc/arch/arm64.ffa.rst
> +
> diff --git a/drivers/firmware/arm-ffa/Makefile b/drivers/firmware/arm-ffa/Makefile
> new file mode 100644
> index 0000000000..11b1766285
> --- /dev/null
> +++ b/drivers/firmware/arm-ffa/Makefile
> @@ -0,0 +1,8 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office at arm.com>
> +#
> +# Authors:
> +#   Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> +
> +obj-y += arm-ffa-uclass.o arm-ffa.o
> diff --git a/drivers/firmware/arm-ffa/arm-ffa-uclass.c b/drivers/firmware/arm-ffa/arm-ffa-uclass.c
> new file mode 100644
> index 0000000000..ffa9d81fa7
> --- /dev/null
> +++ b/drivers/firmware/arm-ffa/arm-ffa-uclass.c
> @@ -0,0 +1,1065 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office at arm.com>
> + *
> + * Authors:
> + *   Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> + */
> +#include <common.h>
> +#include <arm_ffa.h>
> +#include <arm_ffa_priv.h>
> +#include <dm.h>
> +#include <log.h>
> +#include <malloc.h>
> +#include <string.h>
> +#include <uuid.h>
> +#include <asm/global_data.h>
> +#include <dm/device-internal.h>
> +#include <dm/devres.h>
> +#include <dm/root.h>
> +#include <linux/errno.h>
> +#include <linux/sizes.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +/* Error mapping declarations */
> +
> +int ffa_to_std_errmap[MAX_NUMBER_FFA_ERR] = {
> +	[NOT_SUPPORTED] = -EOPNOTSUPP,
> +	[INVALID_PARAMETERS] = -EINVAL,
> +	[NO_MEMORY] = -ENOMEM,
> +	[BUSY] = -EBUSY,
> +	[INTERRUPTED] = -EINTR,
> +	[DENIED] = -EACCES,
> +	[RETRY] = -EAGAIN,
> +	[ABORTED] = -ECANCELED,
> +};
> +
> +static struct ffa_abi_errmap err_msg_map[FFA_ERRMAP_COUNT] = {
> +	[FFA_ID_TO_ERRMAP_ID(FFA_VERSION)] = {
> +		{
> +			[NOT_SUPPORTED] =
> +			"NOT_SUPPORTED: A Firmware Framework implementation does not exist",
> +		},
> +	},
> +	[FFA_ID_TO_ERRMAP_ID(FFA_ID_GET)] = {
> +		{
> +			[NOT_SUPPORTED] =
> +			"NOT_SUPPORTED: This function is not implemented at this FF-A instance",
> +		},
> +	},
> +	[FFA_ID_TO_ERRMAP_ID(FFA_FEATURES)] = {
> +		{
> +			[NOT_SUPPORTED] =
> +			"NOT_SUPPORTED: FFA_RXTX_MAP is not implemented at this FF-A instance",
> +		},
> +	},
> +	[FFA_ID_TO_ERRMAP_ID(FFA_PARTITION_INFO_GET)] = {
> +		{
> +			[NOT_SUPPORTED] =
> +			"NOT_SUPPORTED: This function is not implemented at this FF-A instance",
> +			[INVALID_PARAMETERS] =
> +			"INVALID_PARAMETERS: Unrecognized UUID",
> +			[NO_MEMORY] =
> +			"NO_MEMORY: Results cannot fit in RX buffer of the caller",
> +			[BUSY] =
> +			"BUSY: RX buffer of the caller is not free",
> +			[DENIED] =
> +			"DENIED: Callee is not in a state to handle this request",
> +		},
> +	},
> +	[FFA_ID_TO_ERRMAP_ID(FFA_RXTX_UNMAP)] = {
> +		{
> +			[NOT_SUPPORTED] =
> +			"NOT_SUPPORTED: FFA_RXTX_UNMAP is not implemented at this FF-A instance",
> +			[INVALID_PARAMETERS] =
> +			"INVALID_PARAMETERS: No buffer pair registered on behalf of the caller",
> +		},
> +	},
> +	[FFA_ID_TO_ERRMAP_ID(FFA_RX_RELEASE)] = {
> +		{
> +			[NOT_SUPPORTED] =
> +			"NOT_SUPPORTED: FFA_RX_RELEASE is not implemented at this FF-A instance",
> +			[DENIED] =
> +			"DENIED: Caller did not have ownership of the RX buffer",
> +		},
> +	},
> +	[FFA_ID_TO_ERRMAP_ID(FFA_RXTX_MAP)] = {
> +		{
> +			[NOT_SUPPORTED] =
> +			"NOT_SUPPORTED: This function is not implemented at this FF-A instance",
> +			[INVALID_PARAMETERS] =
> +			"INVALID_PARAMETERS: Field(s) in input parameters incorrectly encoded",
> +			[NO_MEMORY] =
> +			"NO_MEMORY: Not enough memory",
> +			[DENIED] =
> +			"DENIED: Buffer pair already registered",
> +		},
> +	},
> +};
> +
> +/**
> + * ffa_to_std_errno() - convert FF-A error code to standard error code
> + * @ffa_errno:	Error code returned by the FF-A ABI
> + *
> + * Map the given FF-A error code as specified
> + * by the spec to a u-boot standard error code.
> + *
> + * Return:
> + *
> + * The standard error code on success. . Otherwise, failure
> + */
> +static int ffa_to_std_errno(int ffa_errno)
> +{
> +	int err_idx = -ffa_errno;
> +
> +	/* Map the FF-A error code to the standard u-boot error code */
> +	if (err_idx > 0 && err_idx < MAX_NUMBER_FFA_ERR)
> +		return ffa_to_std_errmap[err_idx];
> +	return -EINVAL;
> +}
> +
> +/**
> + * ffa_print_error_log() - print the error log corresponding to the selected FF-A ABI
> + * @ffa_id:	FF-A ABI ID
> + * @ffa_errno:	Error code returned by the FF-A ABI
> + *
> + * Map the FF-A error code to the error log relevant to the
> + * selected FF-A ABI. Then the error log is printed.
> + *
> + * Return:
> + *
> + * 0 on success. . Otherwise, failure
> + */
> +static int ffa_print_error_log(u32 ffa_id, int ffa_errno)
> +{
> +	int err_idx = -ffa_errno, abi_idx = 0;
> +
> +	/* Map the FF-A error code to the corresponding error log */
> +
> +	if (err_idx <= 0 || err_idx >= MAX_NUMBER_FFA_ERR)
> +		return -EINVAL;
> +
> +	if (ffa_id < FFA_FIRST_ID || ffa_id > FFA_LAST_ID)
> +		return -EINVAL;
> +
> +	abi_idx = FFA_ID_TO_ERRMAP_ID(ffa_id);
> +	if (abi_idx < 0 || abi_idx >= FFA_ERRMAP_COUNT)
> +		return -EINVAL;
> +
> +	if (!err_msg_map[abi_idx].err_str[err_idx])
> +		return -EINVAL;
> +
> +	log_err("%s\n", err_msg_map[abi_idx].err_str[err_idx]);
> +
> +	return 0;
> +}
> +
> +/* FF-A ABIs implementation (U-Boot side) */
> +
> +/**
> + * invoke_ffa_fn() - SMC wrapper
> + * @args: FF-A ABI arguments to be copied to Xn registers
> + * @res: FF-A ABI return data to be copied from Xn registers
> + *
> + * Calls low level SMC implementation.
> + * This function should be implemented by the user driver.
> + */
> +void __weak invoke_ffa_fn(ffa_value_t args, ffa_value_t *res)
> +{
> +}
> +
> +/**
> + * ffa_get_version_hdlr() - FFA_VERSION handler function
> + * @dev: The FF-A bus device
> + *
> + * Implement FFA_VERSION FF-A function
> + * to get from the secure world the FF-A framework version
> + * FFA_VERSION is used to discover the FF-A framework.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_get_version_hdlr(struct udevice *dev)
> +{
> +	u16 major, minor;
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +	struct ffa_priv *uc_priv;
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_32(FFA_VERSION), .a1 = FFA_VERSION_1_0,
> +			}, &res);
> +
> +	ffa_errno = res.a0;
> +	if (ffa_errno < 0) {
> +		ffa_print_error_log(FFA_VERSION, ffa_errno);
> +		return ffa_to_std_errno(ffa_errno);
> +	}
> +
> +	major = GET_FFA_MAJOR_VERSION(res.a0);
> +	minor = GET_FFA_MINOR_VERSION(res.a0);
> +
> +	log_info("FF-A driver %d.%d\nFF-A framework %d.%d\n",
> +		 FFA_MAJOR_VERSION, FFA_MINOR_VERSION, major, minor);
> +
> +	if (major == FFA_MAJOR_VERSION && minor >= FFA_MINOR_VERSION) {
> +		log_info("FF-A versions are compatible\n");
> +
> +		if (dev) {
> +			uc_priv = dev_get_uclass_priv(dev);
> +			if (uc_priv)
> +				uc_priv->fwk_version = res.a0;
> +		}
> +
> +		return 0;
> +	}
> +
> +	log_err("versions are incompatible\nExpected: %d.%d , Found: %d.%d\n",
> +		FFA_MAJOR_VERSION, FFA_MINOR_VERSION, major, minor);
> +
> +	return -EPROTONOSUPPORT;
> +}
> +
> +/**
> + * ffa_get_endpoint_id() - FFA_ID_GET handler function
> + * @dev: The FF-A bus device
> + *
> + * Implement FFA_ID_GET FF-A function
> + * to get from the secure world u-boot endpoint ID
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_get_endpoint_id(struct udevice *dev)
> +{
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +	struct ffa_priv *uc_priv = dev_get_uclass_priv(dev);
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_32(FFA_ID_GET),
> +			}, &res);
> +
> +	if (res.a0 == FFA_SMC_32(FFA_SUCCESS)) {
> +		uc_priv->id = GET_SELF_ENDPOINT_ID((u32)res.a2);
> +		log_debug("FF-A endpoint ID is %u\n", uc_priv->id);
> +
> +		return 0;
> +	}
> +
> +	ffa_errno = res.a2;
> +
> +	ffa_print_error_log(FFA_ID_GET, ffa_errno);
> +
> +	return ffa_to_std_errno(ffa_errno);
> +}
> +
> +/**
> + * ffa_set_rxtx_buffers_pages_cnt() - set the minimum number of pages in each of the RX/TX buffers
> + * @dev: The FF-A bus device
> + * @prop_field: properties field obtained from FFA_FEATURES ABI
> + *
> + * Set the minimum number of pages in each of the RX/TX buffers in uc_priv
> + *
> + * Return:
> + *
> + * rxtx_min_pages field contains the returned number of pages
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_set_rxtx_buffers_pages_cnt(struct udevice *dev, u32 prop_field)
> +{
> +	struct ffa_priv *uc_priv = dev_get_uclass_priv(dev);
> +
> +	switch (prop_field) {
> +	case RXTX_4K:
> +		uc_priv->pair.rxtx_min_pages = 1;
> +		break;
> +	case RXTX_16K:
> +		uc_priv->pair.rxtx_min_pages = 4;
> +		break;
> +	case RXTX_64K:
> +		uc_priv->pair.rxtx_min_pages = 16;
> +		break;
> +	default:
> +		log_err("RX/TX buffer size not supported\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * ffa_get_rxtx_map_features_hdlr() - FFA_FEATURES handler function with FFA_RXTX_MAP argument
> + * @dev: The FF-A bus device
> + *
> + * Implement FFA_FEATURES FF-A function to retrieve the FFA_RXTX_MAP features
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_get_rxtx_map_features_hdlr(struct udevice *dev)
> +{
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_32(FFA_FEATURES),
> +			.a1 = FFA_SMC_64(FFA_RXTX_MAP),
> +			}, &res);
> +
> +	if (res.a0 == FFA_SMC_32(FFA_SUCCESS))
> +		return ffa_set_rxtx_buffers_pages_cnt(dev, res.a2);
> +
> +	ffa_errno = res.a2;
> +	ffa_print_error_log(FFA_FEATURES, ffa_errno);
> +
> +	return ffa_to_std_errno(ffa_errno);
> +}
> +
> +/**
> + * ffa_free_rxtx_buffers() - free the RX/TX buffers
> + * @dev: The FF-A bus device
> + *
> + * Free the RX/TX buffers
> + */
> +static void ffa_free_rxtx_buffers(struct udevice *dev)
> +{
> +	struct ffa_priv *uc_priv = dev_get_uclass_priv(dev);
> +
> +	log_debug("Freeing FF-A RX/TX buffers\n");
> +
> +	if (uc_priv->pair.rxbuf) {
> +		free(uc_priv->pair.rxbuf);
> +		uc_priv->pair.rxbuf = NULL;
> +	}
> +
> +	if (uc_priv->pair.txbuf) {
> +		free(uc_priv->pair.txbuf);
> +		uc_priv->pair.txbuf = NULL;
> +	}
> +}
> +
> +/**
> + * ffa_alloc_rxtx_buffers() - allocate the RX/TX buffers
> + * @dev: The FF-A bus device
> + *
> + * Used by ffa_map_rxtx_buffers to allocate
> + * the RX/TX buffers before mapping them. The allocated memory is physically
> + * contiguous since memalign ends up calling malloc which allocates
> + * contiguous memory in u-boot.
> + * The size of the memory allocated is the minimum allowed.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_alloc_rxtx_buffers(struct udevice *dev)
> +{
> +	u64 bytes;
> +	struct ffa_priv *uc_priv = dev_get_uclass_priv(dev);
> +
> +	log_debug("Using %lu 4KB page(s) for FF-A RX/TX buffers size\n",
> +		  uc_priv->pair.rxtx_min_pages);
> +
> +	bytes = uc_priv->pair.rxtx_min_pages * SZ_4K;
> +
> +	/*
> +	 * The alignment of the RX and TX buffers must be equal
> +	 * to the larger translation granule size
> +	 * Assumption: Memory allocated with memalign is always physically contiguous
> +	 */
> +
> +	uc_priv->pair.rxbuf = memalign(bytes, bytes);
> +	if (!uc_priv->pair.rxbuf) {
> +		log_err("failure to allocate RX buffer\n");
> +		return -ENOBUFS;
> +	}
> +
> +	log_debug("FF-A RX buffer at virtual address %p\n", uc_priv->pair.rxbuf);
> +
> +	uc_priv->pair.txbuf = memalign(bytes, bytes);
> +	if (!uc_priv->pair.txbuf) {
> +		free(uc_priv->pair.rxbuf);
> +		uc_priv->pair.rxbuf = NULL;
> +		log_err("failure to allocate the TX buffer\n");
> +		return -ENOBUFS;
> +	}
> +
> +	log_debug("FF-A TX buffer at virtual address %p\n", uc_priv->pair.txbuf);
> +
> +	/* Make sure the buffers are cleared before use */
> +	memset(uc_priv->pair.rxbuf, 0, bytes);
> +	memset(uc_priv->pair.txbuf, 0, bytes);
> +
> +	return 0;
> +}
> +
> +/**
> + * ffa_map_rxtx_buffers_hdlr() - FFA_RXTX_MAP handler function
> + * @dev: The FF-A bus device
> + *
> + * Implement FFA_RXTX_MAP FF-A function to map the RX/TX buffers
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_map_rxtx_buffers_hdlr(struct udevice *dev)
> +{
> +	int ret;
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +	struct ffa_priv *uc_priv = dev_get_uclass_priv(dev);
> +
> +	ret = ffa_alloc_rxtx_buffers(dev);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * we need to pass the physical addresses of the RX/TX buffers
> +	 * in u-boot physical/virtual mapping is 1:1
> +	 * no need to convert from virtual to physical
> +	 */
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_64(FFA_RXTX_MAP),
> +			.a1 = map_to_sysmem(uc_priv->pair.txbuf),
> +			.a2 = map_to_sysmem(uc_priv->pair.rxbuf),
> +			.a3 = uc_priv->pair.rxtx_min_pages,
> +			}, &res);
> +
> +	if (res.a0 == FFA_SMC_32(FFA_SUCCESS)) {
> +		log_debug("FF-A RX/TX buffers mapped\n");
> +		return 0;
> +	}
> +
> +	ffa_errno = res.a2;
> +	ffa_print_error_log(FFA_RXTX_MAP, ffa_errno);
> +
> +	ffa_free_rxtx_buffers(dev);
> +
> +	return ffa_to_std_errno(ffa_errno);
> +}
> +
> +/**
> + * ffa_unmap_rxtx_buffers_hdlr() - FFA_RXTX_UNMAP handler function
> + * @dev: The FF-A bus device
> + *
> + * Implement FFA_RXTX_UNMAP FF-A function to unmap the RX/TX buffers
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_unmap_rxtx_buffers_hdlr(struct udevice *dev)
> +{
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +	struct ffa_priv *uc_priv;
> +
> +	log_debug("unmapping FF-A RX/TX buffers\n");
> +
> +	uc_priv = dev_get_uclass_priv(dev);
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_32(FFA_RXTX_UNMAP),
> +			.a1 = PREP_SELF_ENDPOINT_ID(uc_priv->id),
> +			}, &res);
> +
> +	if (res.a0 == FFA_SMC_32(FFA_SUCCESS)) {
> +		ffa_free_rxtx_buffers(dev);
> +		return 0;
> +	}
> +
> +	ffa_errno = res.a2;
> +	ffa_print_error_log(FFA_RXTX_UNMAP, ffa_errno);
> +
> +	return ffa_to_std_errno(ffa_errno);
> +}
> +
> +/**
> + * ffa_release_rx_buffer_hdlr() - FFA_RX_RELEASE handler function
> + * @dev: The FF-A bus device
> + *
> + * Invoke FFA_RX_RELEASE FF-A function to release the ownership of the RX buffer
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_release_rx_buffer_hdlr(struct udevice *dev)
> +{
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_32(FFA_RX_RELEASE),
> +			}, &res);
> +
> +	if (res.a0 == FFA_SMC_32(FFA_SUCCESS))
> +		return 0;
> +
> +	ffa_errno = res.a2;
> +	ffa_print_error_log(FFA_RX_RELEASE, ffa_errno);
> +
> +	return ffa_to_std_errno(ffa_errno);
> +}
> +
> +/**
> + * ffa_uuid_are_identical() - check whether two given UUIDs are identical
> + * @uuid1: first UUID
> + * @uuid2: second UUID
> + *
> + * Used by ffa_read_partitions_info to search for a UUID in the partitions descriptors table
> + *
> + * Return:
> + *
> + * 1 when UUIDs match. Otherwise, 0
> + */
> +static bool ffa_uuid_are_identical(const struct ffa_partition_uuid *uuid1,
> +				   const struct ffa_partition_uuid *uuid2)
> +{
> +	if (!uuid1 || !uuid2)
> +		return 0;
> +
> +	return !memcmp(uuid1, uuid2, sizeof(struct ffa_partition_uuid));
> +}
> +
> +/**
> + * ffa_read_partitions_info() - read queried partition data
> + * @dev: The FF-A bus device
> + * @count: The number of partitions queried
> + * @part_uuid: Pointer to the partition(s) UUID
> + *
> + * Read the partitions information returned by the FFA_PARTITION_INFO_GET and saves it in uc_priv
> + *
> + * Return:
> + *
> + * uc_priv is updated with the partition(s) information
> + * 0 is returned on success. Otherwise, failure
> + */
> +static int ffa_read_partitions_info(struct udevice *dev, u32 count,
> +				    struct ffa_partition_uuid *part_uuid)
> +{
> +	struct ffa_priv *uc_priv = dev_get_uclass_priv(dev);
> +
> +	if (!count) {
> +		log_err("no partition detected\n");
> +		return -ENODATA;
> +	}
> +
> +	log_debug("Reading FF-A partitions data from the RX buffer\n");
> +
> +	if (!part_uuid) {
> +		/* Querying information of all partitions */
> +		u64 buf_bytes;
> +		u64 data_bytes;
> +		u32 desc_idx;
> +		struct ffa_partition_info *parts_info;
> +
> +		data_bytes = count * sizeof(struct ffa_partition_desc);
> +
> +		buf_bytes = uc_priv->pair.rxtx_min_pages * SZ_4K;
> +
> +		if (data_bytes > buf_bytes) {
> +			log_err("partitions data size exceeds the RX buffer size:\n");
> +			log_err("    sizes in bytes: data %llu , RX buffer %llu\n",
> +				data_bytes,
> +				buf_bytes);
> +
> +			return -ENOMEM;
> +		}
> +
> +		uc_priv->partitions.descs = devm_kmalloc(dev, data_bytes, __GFP_ZERO);
> +		if (!uc_priv->partitions.descs) {
> +			log_err("cannot  allocate partitions data buffer\n");
> +			return -ENOMEM;
> +		}
> +
> +		parts_info = uc_priv->pair.rxbuf;
> +
> +		for (desc_idx = 0 ; desc_idx < count ; desc_idx++) {
> +			uc_priv->partitions.descs[desc_idx].info =
> +				parts_info[desc_idx];
> +
> +			log_debug("FF-A partition ID %x : info cached\n",
> +				  uc_priv->partitions.descs[desc_idx].info.id);
> +		}
> +
> +		uc_priv->partitions.count = count;
> +
> +		log_debug("%d FF-A partition(s) found and cached\n", count);
> +
> +	} else {
> +		u32 rx_desc_idx, cached_desc_idx;
> +		struct ffa_partition_info *parts_info;
> +		u8 desc_found;
> +
> +		parts_info = uc_priv->pair.rxbuf;
> +
> +		/*
> +		 * Search for the SP IDs read from the RX buffer
> +		 * in the already cached SPs.
> +		 * Update the UUID when ID found.
> +		 */
> +		for (rx_desc_idx = 0; rx_desc_idx < count ; rx_desc_idx++) {
> +			desc_found = 0;
> +
> +			/* Search the current ID in the cached partitions */
> +			for (cached_desc_idx = 0;
> +			     cached_desc_idx < uc_priv->partitions.count;
> +			     cached_desc_idx++) {
> +				/* Save the UUID */
> +				if (uc_priv->partitions.descs[cached_desc_idx].info.id ==
> +				    parts_info[rx_desc_idx].id) {
> +					uc_priv->partitions.descs[cached_desc_idx].sp_uuid =
> +						*part_uuid;
> +
> +					desc_found = 1;
> +					break;
> +				}
> +			}
> +
> +			if (!desc_found)
> +				return -ENODATA;
> +		}
> +	}
> +
> +	return  0;
> +}
> +
> +/**
> + * ffa_query_partitions_info() - invoke FFA_PARTITION_INFO_GET and save partitions data
> + * @dev: The FF-A bus device
> + * @part_uuid: Pointer to the partition(s) UUID
> + * @pcount: Pointer to the number of partitions variable filled when querying
> + *
> + * Execute the FFA_PARTITION_INFO_GET to query the partitions data.
> + * Then, call ffa_read_partitions_info to save the data in uc_priv.
> + *
> + * After reading the data the RX buffer is released using ffa_release_rx_buffer
> + *
> + * Return:
> + *
> + * When part_uuid is NULL, all partitions data are retrieved from secure world
> + * When part_uuid is non NULL, data for partitions matching the given UUID are
> + * retrieved and the number of partitions is returned
> + * 0 is returned on success. Otherwise, failure
> + */
> +static int ffa_query_partitions_info(struct udevice *dev, struct ffa_partition_uuid *part_uuid,
> +				     u32 *pcount)
> +{
> +	struct ffa_partition_uuid query_uuid = {0};
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +
> +	/*
> +	 * If a UUID is specified. Information for one or more
> +	 * partitions in the system is queried. Otherwise, information
> +	 * for all installed partitions is queried
> +	 */
> +
> +	if (part_uuid) {
> +		if (!pcount)
> +			return -EINVAL;
> +
> +		query_uuid = *part_uuid;
> +	} else if (pcount) {
> +		return -EINVAL;
> +	}
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_32(FFA_PARTITION_INFO_GET),
> +			.a1 = query_uuid.a1,
> +			.a2 = query_uuid.a2,
> +			.a3 = query_uuid.a3,
> +			.a4 = query_uuid.a4,
> +			}, &res);
> +
> +	if (res.a0 == FFA_SMC_32(FFA_SUCCESS)) {
> +		int ret;
> +
> +		/*
> +		 * res.a2 contains the count of partition information descriptors
> +		 * populated in the RX buffer
> +		 */
> +		if (res.a2) {
> +			ret = ffa_read_partitions_info(dev, (u32)res.a2, part_uuid);
> +			if (ret) {
> +				log_err("failed reading SP(s) data , err (%d)\n", ret);
> +				ffa_release_rx_buffer_hdlr(dev);
> +				return -EINVAL;
> +			}
> +		}
> +
> +		/* Return the SP count (when querying using a UUID) */
> +		if (pcount)
> +			*pcount = (u32)res.a2;
> +
> +		/*
> +		 * After calling FFA_PARTITION_INFO_GET the buffer ownership
> +		 * is assigned to the consumer (u-boot). So, we need to give
> +		 * the ownership back to the SPM or hypervisor
> +		 */
> +		ret = ffa_release_rx_buffer_hdlr(dev);
> +
> +		return ret;
> +	}
> +
> +	ffa_errno = res.a2;
> +	ffa_print_error_log(FFA_PARTITION_INFO_GET, ffa_errno);
> +
> +	return ffa_to_std_errno(ffa_errno);
> +}
> +
> +/**
> + * ffa_get_partitions_info_hdlr() - FFA_PARTITION_INFO_GET handler function
> + *	@uuid_str: pointer to the UUID string
> + *	@sp_count: address of the variable containing the number of partitions matching the UUID
> + *			 The variable is set by the driver
> + *	@sp_descs: address of the descriptors of the partitions matching the UUID
> + *			 The address is set by the driver
> + *
> + * Return the number of partitions and their descriptors matching the UUID
> + *
> + * Query the secure partition data from uc_priv.
> + * If not found, invoke FFA_PARTITION_INFO_GET FF-A function to query the partition information
> + * from secure world.
> + *
> + * A client of the FF-A driver should know the UUID of the service it wants to
> + * access. It should use the UUID to request the FF-A driver to provide the
> + * partition(s) information of the service. The FF-A driver uses
> + * PARTITION_INFO_GET to obtain this information. This is implemented through
> + * ffa_get_partitions_info_hdlr() function.
> + * If the partition(s) matching the UUID found, the partition(s) information and the
> + * number are returned.
> + * If no partition matching the UUID is found in the cached area, a new FFA_PARTITION_INFO_GET
> + * call is issued.
> + * If not done yet, the UUID is updated in the cached area.
> + * This assumes that partitions data does not change in the secure world.
> + * Otherwise u-boot will have an outdated partition data. The benefit of caching
> + * the information in the FF-A driver is to accommodate discovery after
> + * ExitBootServices().
> + *
> + * Return:
> + *
> + * @sp_count: the number of partitions
> + * @sp_descs: address of the partitions descriptors
> + *
> + * On success 0 is returned. Otherwise, failure
> + */
> +int ffa_get_partitions_info_hdlr(struct udevice *dev, const char *uuid_str,
> +				 u32 *sp_count, struct ffa_partition_desc **sp_descs)
> +{
> +	u32 i;
> +	struct ffa_partition_uuid part_uuid = {0};
> +	struct ffa_priv *uc_priv;
> +	struct ffa_partition_desc *rx_descs;
> +
> +	uc_priv = dev_get_uclass_priv(dev);
> +
> +	if (!uc_priv->partitions.count || !uc_priv->partitions.descs) {
> +		log_err("no partition installed\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!uuid_str) {
> +		log_err("no UUID provided\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!sp_count) {
> +		log_err("no count argument provided\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!sp_descs) {
> +		log_err("no info argument provided\n");
> +		return -EINVAL;
> +	}
> +
> +	if (uuid_str_to_le_bin(uuid_str, (unsigned char *)&part_uuid)) {
> +		log_err("invalid UUID\n");
> +		return -EINVAL;
> +	}
> +
> +	log_debug("Searching FF-A partitions using the provided UUID\n");
> +
> +	*sp_count = 0;
> +	*sp_descs = uc_priv->pair.rxbuf;
> +	rx_descs = *sp_descs;
> +
> +	/* Search in the cached partitions */
> +	for (i = 0; i < uc_priv->partitions.count; i++)
> +		if (ffa_uuid_are_identical(&uc_priv->partitions.descs[i].sp_uuid,
> +					   &part_uuid)) {
> +			log_debug("FF-A partition ID %x matches the provided UUID\n",
> +				  uc_priv->partitions.descs[i].info.id);
> +
> +			(*sp_count)++;
> +			*rx_descs++ = uc_priv->partitions.descs[i];
> +			}
> +
> +	if (!(*sp_count)) {
> +		int ret;
> +
> +		log_debug("No FF-A partition found. Querying framework ...\n");
> +
> +		ret = ffa_query_partitions_info(dev, &part_uuid, sp_count);
> +
> +		if (!ret) {
> +			log_debug("Number of FF-A partition(s) matching the UUID: %d\n", *sp_count);
> +
> +			if (*sp_count)
> +				ret = ffa_get_partitions_info_hdlr(dev, uuid_str, sp_count,
> +								   sp_descs);
> +			else
> +				ret = -ENODATA;
> +		}
> +
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * ffa_cache_partitions_info() - Query and saves all secure partitions data
> + * @dev: The FF-A bus device
> + *
> + * Invoke FFA_PARTITION_INFO_GET FF-A function to query from secure world
> + * all partitions information.
> + *
> + * The FFA_PARTITION_INFO_GET call is issued with nil UUID as an argument.
> + * All installed partitions information are returned. We cache them in uc_priv
> + * and we keep the UUID field empty (in FF-A 1.0 UUID is not provided by the partition descriptor)
> + *
> + * Called at the device probing level.
> + * ffa_cache_partitions_info uses ffa_query_partitions_info to get the data
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_cache_partitions_info(struct udevice *dev)
> +{
> +	return ffa_query_partitions_info(dev, NULL, NULL);
> +}
> +
> +/**
> + * ffa_msg_send_direct_req_hdlr() - FFA_MSG_SEND_DIRECT_{REQ,RESP} handler function
> + * @dev: The FF-A bus device
> + * @dst_part_id: destination partition ID
> + * @msg: pointer to the message data preallocated by the client (in/out)
> + * @is_smc64: select 64-bit or 32-bit FF-A ABI
> + *
> + * Implement FFA_MSG_SEND_DIRECT_{REQ,RESP}
> + * FF-A functions.
> + *
> + * FFA_MSG_SEND_DIRECT_REQ is used to send the data to the secure partition.
> + * The response from the secure partition is handled by reading the
> + * FFA_MSG_SEND_DIRECT_RESP arguments.
> + *
> + * The maximum size of the data that can be exchanged is 40 bytes which is
> + * sizeof(struct ffa_send_direct_data) as defined by the FF-A specification 1.0
> + * in the section relevant to FFA_MSG_SEND_DIRECT_{REQ,RESP}
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_msg_send_direct_req_hdlr(struct udevice *dev, u16 dst_part_id,
> +				 struct ffa_send_direct_data *msg, bool is_smc64)
> +{
> +	ffa_value_t res = {0};
> +	int ffa_errno;
> +	u64 req_mode, resp_mode;
> +	struct ffa_priv *uc_priv;
> +
> +	uc_priv = dev_get_uclass_priv(dev);
> +
> +	/* No partition installed */
> +	if (!uc_priv->partitions.count || !uc_priv->partitions.descs)
> +		return -ENODEV;
> +
> +	if (is_smc64) {
> +		req_mode = FFA_SMC_64(FFA_MSG_SEND_DIRECT_REQ);
> +		resp_mode = FFA_SMC_64(FFA_MSG_SEND_DIRECT_RESP);
> +	} else {
> +		req_mode = FFA_SMC_32(FFA_MSG_SEND_DIRECT_REQ);
> +		resp_mode = FFA_SMC_32(FFA_MSG_SEND_DIRECT_RESP);
> +	}
> +
> +	invoke_ffa_fn((ffa_value_t){
> +			.a0 = req_mode,
> +			.a1 = PREP_SELF_ENDPOINT_ID(uc_priv->id) |
> +				PREP_PART_ENDPOINT_ID(dst_part_id),
> +			.a2 = 0,
> +			.a3 = msg->data0,
> +			.a4 = msg->data1,
> +			.a5 = msg->data2,
> +			.a6 = msg->data3,
> +			.a7 = msg->data4,
> +			}, &res);
> +
> +	while (res.a0 == FFA_SMC_32(FFA_INTERRUPT))
> +		invoke_ffa_fn((ffa_value_t){
> +			.a0 = FFA_SMC_32(FFA_RUN),
> +			.a1 = res.a1,
> +			}, &res);
> +
> +	if (res.a0 == FFA_SMC_32(FFA_SUCCESS)) {
> +		/* Message sent with no response */
> +		return 0;
> +	}
> +
> +	if (res.a0 == resp_mode) {
> +		/* Message sent with response extract the return data */
> +		msg->data0 = res.a3;
> +		msg->data1 = res.a4;
> +		msg->data2 = res.a5;
> +		msg->data3 = res.a6;
> +		msg->data4 = res.a7;
> +
> +		return 0;
> +	}
> +
> +	ffa_errno = res.a2;
> +	return ffa_to_std_errno(ffa_errno);
> +}
> +
> +/* FF-A driver operations (used by clients for communicating with FF-A)*/
> +
> +/**
> + * ffa_partition_info_get() - FFA_PARTITION_INFO_GET driver operation
> + *	@uuid_str: pointer to the UUID string
> + *	@sp_count: address of the variable containing the number of partitions matching the UUID
> + *			 The variable is set by the driver
> + *	@sp_descs: address of the descriptors of the partitions matching the UUID
> + *			 The address is set by the driver
> + *
> + * Driver operation for FFA_PARTITION_INFO_GET.
> + * Please see ffa_get_partitions_info_hdlr() description for more details.
> + *
> + * Return:
> + *
> + * @sp_count: the number of partitions
> + * @sp_descs: address of the partitions descriptors
> + *
> + * On success 0 is returned. Otherwise, failure
> + */
> +int ffa_partition_info_get(struct udevice *dev, const char *uuid_str,
> +			   u32 *sp_count, struct ffa_partition_desc **sp_descs)
> +{
> +	struct ffa_bus_ops *ops = ffa_get_ops(dev);
> +
> +	if (!ops->partition_info_get)
> +		return -ENOSYS;
> +
> +	return ops->partition_info_get(dev, uuid_str, sp_count, sp_descs);
> +}
> +
> +/**
> + * ffa_sync_send_receive() - FFA_MSG_SEND_DIRECT_{REQ,RESP} driver operation
> + * @dev: The FF-A bus device
> + * @dst_part_id: destination partition ID
> + * @msg: pointer to the message data preallocated by the client (in/out)
> + * @is_smc64: select 64-bit or 32-bit FF-A ABI
> + *
> + * Driver operation for FFA_MSG_SEND_DIRECT_{REQ,RESP}.
> + * Please see ffa_msg_send_direct_req_hdlr() description for more details.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_sync_send_receive(struct udevice *dev, u16 dst_part_id,
> +			  struct ffa_send_direct_data *msg, bool is_smc64)
> +{
> +	struct ffa_bus_ops *ops = ffa_get_ops(dev);
> +
> +	if (!ops->sync_send_receive)
> +		return -ENOSYS;
> +
> +	return ops->sync_send_receive(dev, dst_part_id, msg, is_smc64);
> +}
> +
> +/**
> + * ffa_rxtx_unmap() - FFA_RXTX_UNMAP driver operation
> + * @dev: The FF-A bus device
> + *
> + * Driver operation for FFA_RXTX_UNMAP.
> + * Please see ffa_unmap_rxtx_buffers_hdlr() description for more details.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_rxtx_unmap(struct udevice *dev)
> +{
> +	struct ffa_bus_ops *ops = ffa_get_ops(dev);
> +
> +	if (!ops->rxtx_unmap)
> +		return -ENOSYS;
> +
> +	return ops->rxtx_unmap(dev);
> +}
> +
> +/**
> + * ffa_do_probe() - probing FF-A framework
> + * @dev:	the FF-A bus device (arm_ffa)
> + *
> + * Probing is triggered on demand by clients searching for the uclass.
> + * At probe level the following actions are done:
> + *	- 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
> + *
> + * All data queried from secure world is saved in uc_priv.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static int ffa_do_probe(struct udevice *dev)
> +{
> +	int ret;
> +
> +	ret = ffa_get_version_hdlr(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = ffa_get_endpoint_id(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = ffa_get_rxtx_map_features_hdlr(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = ffa_map_rxtx_buffers_hdlr(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = ffa_cache_partitions_info(dev);
> +	if (ret) {
> +		ffa_unmap_rxtx_buffers_hdlr(dev);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +UCLASS_DRIVER(ffa) = {
> +	.name			= "ffa",
> +	.id			= UCLASS_FFA,
> +	.pre_probe		= ffa_do_probe,
> +	.pre_remove		= ffa_unmap_rxtx_buffers_hdlr,
> +	.per_device_auto	= sizeof(struct ffa_priv)
> +};
> diff --git a/drivers/firmware/arm-ffa/arm-ffa.c b/drivers/firmware/arm-ffa/arm-ffa.c
> new file mode 100644
> index 0000000000..68df75bd9e
> --- /dev/null
> +++ b/drivers/firmware/arm-ffa/arm-ffa.c
> @@ -0,0 +1,104 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office at arm.com>
> + *
> + * Authors:
> + *   Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> + */
> +
> +#include <common.h>
> +#include <arm_ffa.h>
> +#include <arm_ffa_priv.h>
> +#include <dm.h>
> +#include <log.h>
> +#include <asm/global_data.h>
> +#include <dm/device-internal.h>
> +#include <linux/errno.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +/**
> + * invoke_ffa_fn() - SMC wrapper
> + * @args: FF-A ABI arguments to be copied to Xn registers
> + * @res: FF-A ABI return data to be copied from Xn registers
> + *
> + * Calls low level SMC assembly function
> + */
> +void invoke_ffa_fn(ffa_value_t args, ffa_value_t *res)
> +{
> +	arm_smccc_1_2_smc(&args, res);
> +}
> +
> +/**
> + * arm_ffa_discover() - perform FF-A discovery
> + * @dev: The Arm FF-A bus device (arm_ffa)
> + * Try to discover the FF-A framework. Discovery is performed by
> + * querying the FF-A framework version from secure world using the FFA_VERSION ABI.
> + * Return:
> + *
> + * true on success. Otherwise, false.
> + */
> +static bool arm_ffa_discover(struct udevice *dev)
> +{
> +	int ret;
> +
> +	log_info("Arm FF-A framework discovery\n");
> +
> +	ret = ffa_get_version_hdlr(dev);
> +	if (ret)
> +		return false;
> +
> +	return true;
> +}
> +
> +/**
> + * arm_ffa_is_supported() - FF-A bus discovery callback
> + * @invoke_fn: legacy SMC invoke function (not used)
> + *
> + * Perform FF-A discovery by calling arm_ffa_discover().
> + * Discovery is performed by querying the FF-A framework version from
> + * secure world using the FFA_VERSION ABI.
> + *
> + * The FF-A driver is registered as an SMCCC feature driver. So, features discovery
> + * callbacks are called by the PSCI driver (PSCI device is the SMCCC features
> + * root device).
> + *
> + * The FF-A driver supports the SMCCCv1.2 extended input/output registers.
> + * So, the legacy SMC invocation is not used.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +static bool arm_ffa_is_supported(void (*invoke_fn)(ulong a0, ulong a1,
> +						   ulong a2, ulong a3,
> +						   ulong a4, ulong a5,
> +						   ulong a6, ulong a7,
> +						   struct arm_smccc_res *res))
> +{
> +	return arm_ffa_discover(NULL);
> +}
> +
> +/* Arm FF-A driver operations */
> +
> +static const struct ffa_bus_ops ffa_ops = {
> +	.partition_info_get = ffa_get_partitions_info_hdlr,
> +	.sync_send_receive = ffa_msg_send_direct_req_hdlr,
> +	.rxtx_unmap = ffa_unmap_rxtx_buffers_hdlr,
> +};
> +
> +/* Registering the FF-A driver as an SMCCC feature driver */
> +
> +ARM_SMCCC_FEATURE_DRIVER(arm_ffa) = {
> +	.driver_name = FFA_DRV_NAME,
> +	.is_supported = arm_ffa_is_supported,
> +};
> +
> +/* Declaring the FF-A driver under UCLASS_FFA */
> +
> +U_BOOT_DRIVER(arm_ffa) = {
> +	.name		= FFA_DRV_NAME,
> +	.id		= UCLASS_FFA,
> +	.flags		= DM_REMOVE_OS_PREPARE,
> +	.ops		= &ffa_ops,
> +};
> diff --git a/drivers/firmware/arm-ffa/sandbox_arm_ffa_priv.h b/drivers/firmware/arm-ffa/sandbox_arm_ffa_priv.h
> new file mode 100644
> index 0000000000..4338f9c9b1
> --- /dev/null
> +++ b/drivers/firmware/arm-ffa/sandbox_arm_ffa_priv.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office at arm.com>
> + *
> + * Authors:
> + *   Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> + */
> +
> +#ifndef __SANDBOX_ARM_FFA_PRV_H
> +#define __SANDBOX_ARM_FFA_PRV_H
> +
> +/* Future sandbox support private declarations */
> +
> +#endif
> diff --git a/include/arm_ffa.h b/include/arm_ffa.h
> new file mode 100644
> index 0000000000..db9b1be995
> --- /dev/null
> +++ b/include/arm_ffa.h
> @@ -0,0 +1,213 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office at arm.com>
> + *
> + * Authors:
> + *   Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> + */
> +
> +#ifndef __ARM_FFA_H
> +#define __ARM_FFA_H
> +
> +#include <linux/printk.h>
> +
> +/*
> + * This header is public. It can be used by clients to access
> + * data structures and definitions they need
> + */
> +
> +/*
> + * struct ffa_partition_info - Partition information descriptor
> + * @id:	Partition ID
> + * @exec_ctxt:	Execution context count
> + * @properties:	Partition properties
> + *
> + * Data structure containing information about partitions instantiated in the system
> + * This structure is filled with the data queried by FFA_PARTITION_INFO_GET
> + */
> +struct ffa_partition_info {
> +	u16 id;
> +	u16 exec_ctxt;
> +/* partition supports receipt of direct requests */
> +#define FFA_PARTITION_DIRECT_RECV	BIT(0)
> +/* partition can send direct requests. */
> +#define FFA_PARTITION_DIRECT_SEND	BIT(1)
> +/* partition can send and receive indirect messages. */
> +#define FFA_PARTITION_INDIRECT_MSG	BIT(2)
> +	u32 properties;
> +};
> +
> +/*
> + * struct ffa_partition_uuid - 16 bytes UUID transmitted by FFA_PARTITION_INFO_GET
> + * @a1-4:	32-bit words access to the UUID data
> + *
> + */
> +struct ffa_partition_uuid {
> +	u32 a1; /* w1 */
> +	u32 a2; /* w2 */
> +	u32 a3; /* w3 */
> +	u32 a4; /* w4 */
> +};
> +
> +/**
> + * struct ffa_partition_desc - the secure partition descriptor
> + * @info:	partition information
> + * @sp_uuid:	the secure partition UUID
> + *
> + * Each partition has its descriptor containing the partitions information and the UUID
> + */
> +struct ffa_partition_desc {
> +	struct ffa_partition_info info;
> +	struct ffa_partition_uuid sp_uuid;
> +};
> +
> +/*
> + * struct ffa_send_direct_data - Data structure hosting the data
> + *                                       used by FFA_MSG_SEND_DIRECT_{REQ,RESP}
> + * @data0-4:	Data read/written from/to x3-x7 registers
> + *
> + * Data structure containing the data to be sent by FFA_MSG_SEND_DIRECT_REQ
> + * or read from FFA_MSG_SEND_DIRECT_RESP
> + */
> +
> +/* For use with FFA_MSG_SEND_DIRECT_{REQ,RESP} which pass data via registers */
> +struct ffa_send_direct_data {
> +	ulong data0; /* w3/x3 */
> +	ulong data1; /* w4/x4 */
> +	ulong data2; /* w5/x5 */
> +	ulong data3; /* w6/x6 */
> +	ulong data4; /* w7/x7 */
> +};
> +
> +struct udevice;
> +
> +/**
> + * struct ffa_bus_ops - Operations for FF-A
> + * @partition_info_get:	callback for the FFA_PARTITION_INFO_GET
> + * @sync_send_receive:	callback for the FFA_MSG_SEND_DIRECT_REQ
> + * @rxtx_unmap:	callback for the FFA_RXTX_UNMAP
> + *
> + * The data structure providing all the operations supported by the driver.
> + * This structure is EFI runtime resident.
> + */
> +struct ffa_bus_ops {
> +	int (*partition_info_get)(struct udevice *dev, const char *uuid_str,
> +				  u32 *sp_count, struct ffa_partition_desc **sp_descs);
> +	int (*sync_send_receive)(struct udevice *dev, u16 dst_part_id,
> +				 struct ffa_send_direct_data *msg,
> +				 bool is_smc64);
> +	int (*rxtx_unmap)(struct udevice *dev);
> +};
> +
> +#define ffa_get_ops(dev)        ((struct ffa_bus_ops *)(dev)->driver->ops)
> +
> +/**
> + * ffa_rxtx_unmap() - FFA_RXTX_UNMAP driver operation
> + * Please see ffa_unmap_rxtx_buffers_hdlr() description for more details.
> + */
> +int ffa_rxtx_unmap(struct udevice *dev);
> +
> +/**
> + * ffa_unmap_rxtx_buffers_hdlr() - FFA_RXTX_UNMAP handler function
> + * @dev: The arm_ffa bus device
> + *
> + * This function implements FFA_RXTX_UNMAP FF-A function
> + * to unmap the RX/TX buffers
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_unmap_rxtx_buffers_hdlr(struct udevice *dev);
> +
> +/**
> + * ffa_sync_send_receive() - FFA_MSG_SEND_DIRECT_{REQ,RESP} driver operation
> + * Please see ffa_msg_send_direct_req_hdlr() description for more details.
> + */
> +int ffa_sync_send_receive(struct udevice *dev, u16 dst_part_id,
> +			  struct ffa_send_direct_data *msg, bool is_smc64);
> +
> +/**
> + * ffa_msg_send_direct_req_hdlr() - FFA_MSG_SEND_DIRECT_{REQ,RESP} handler function
> + * @dev: The arm_ffa bus device
> + * @dst_part_id: destination partition ID
> + * @msg: pointer to the message data preallocated by the client (in/out)
> + * @is_smc64: select 64-bit or 32-bit FF-A ABI
> + *
> + * This function implements FFA_MSG_SEND_DIRECT_{REQ,RESP}
> + * FF-A functions.
> + *
> + * FFA_MSG_SEND_DIRECT_REQ is used to send the data to the secure partition.
> + * The response from the secure partition is handled by reading the
> + * FFA_MSG_SEND_DIRECT_RESP arguments.
> + *
> + * The maximum size of the data that can be exchanged is 40 bytes which is
> + * sizeof(struct ffa_send_direct_data) as defined by the FF-A specification 1.0
> + * in the section relevant to FFA_MSG_SEND_DIRECT_{REQ,RESP}
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_msg_send_direct_req_hdlr(struct udevice *dev, u16 dst_part_id,
> +				 struct ffa_send_direct_data *msg, bool is_smc64);
> +
> +/**
> + * ffa_partition_info_get() - FFA_PARTITION_INFO_GET driver operation
> + * Please see ffa_get_partitions_info_hdlr() description for more details.
> + */
> +int ffa_partition_info_get(struct udevice *dev, const char *uuid_str,
> +			   u32 *sp_count, struct ffa_partition_desc **sp_descs);
> +
> +/**
> + * ffa_get_partitions_info_hdlr() - FFA_PARTITION_INFO_GET handler function
> + *	@uuid_str: pointer to the UUID string
> + *	@sp_count: address of the variable containing the number of partitions matching the UUID
> + *			 The variable is set by the driver
> + *	@sp_descs: address of the descriptors of the partitions matching the UUID
> + *			 The address is set by the driver
> + *
> + * Return the number of partitions and their descriptors matching the UUID
> + *
> + * Query the secure partition data from uc_priv.
> + * If not found, invoke FFA_PARTITION_INFO_GET
> + * FF-A function to query the partition information from secure world.
> + *
> + * A client of the FF-A driver should know the UUID of the service it wants to
> + * access. It should use the UUID to request the FF-A driver to provide the
> + * partition(s) information of the service. The FF-A driver uses
> + * PARTITION_INFO_GET to obtain this information. This is implemented through
> + * ffa_get_partitions_info_hdlr() function.
> + * A new FFA_PARTITION_INFO_GET call is issued (first one performed through
> + * ffa_cache_partitions_info) allowing to retrieve the partition(s) information.
> + * They are not saved (already done). We only update the UUID in the cached area.
> + * This assumes that partitions data does not change in the secure world.
> + * Otherwise u-boot will have an outdated partition data. The benefit of caching
> + * the information in the FF-A driver is to accommodate discovery after
> + * ExitBootServices().
> + *
> + * Return:
> + *
> + * @sp_count: the number of partitions
> + * @sp_descs: address of the partitions descriptors
> + *
> + * On success 0 is returned. Otherwise, failure
> + */
> +int ffa_get_partitions_info_hdlr(struct udevice *dev, const char *uuid_str,
> +				 u32 *sp_count, struct ffa_partition_desc **sp_descs);
> +
> +struct ffa_priv;
> +
> +/**
> + * ffa_set_smc_conduit() - Set the SMC conduit
> + * @dev: The FF-A bus device
> + *
> + * Selects the SMC conduit by setting the FF-A ABI invoke function.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_set_smc_conduit(struct udevice *dev);
> +
> +#endif
> diff --git a/include/arm_ffa_priv.h b/include/arm_ffa_priv.h
> new file mode 100644
> index 0000000000..d564c33c64
> --- /dev/null
> +++ b/include/arm_ffa_priv.h
> @@ -0,0 +1,246 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office at arm.com>
> + *
> + * Authors:
> + *   Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> + */
> +
> +#ifndef __ARM_FFA_PRV_H
> +#define __ARM_FFA_PRV_H
> +
> +#include <mapmem.h>
> +#include <linux/bitfield.h>
> +#include <linux/bitops.h>
> +
> +/* This header is exclusively used by the FF-A Uclass and FF-A driver(s) */
> +
> +/* Arm FF-A driver name */
> +#define FFA_DRV_NAME "arm_ffa"
> +
> +/* The FF-A SMC function definitions */
> +
> +#if CONFIG_IS_ENABLED(SANDBOX)
> +
> +/* Providing Arm SMCCC declarations to sandbox */
> +
> +/**
> + * struct sandbox_smccc_1_2_regs - emulated SMC call arguments or results
> + * @a0-a17 argument values from registers 0 to 17
> + */
> +struct sandbox_smccc_1_2_regs {
> +	ulong a0;
> +	ulong a1;
> +	ulong a2;
> +	ulong a3;
> +	ulong a4;
> +	ulong a5;
> +	ulong a6;
> +	ulong a7;
> +	ulong a8;
> +	ulong a9;
> +	ulong a10;
> +	ulong a11;
> +	ulong a12;
> +	ulong a13;
> +	ulong a14;
> +	ulong a15;
> +	ulong a16;
> +	ulong a17;
> +};
> +
> +typedef struct sandbox_smccc_1_2_regs ffa_value_t;
> +
> +#define ARM_SMCCC_FAST_CALL		1UL
> +#define ARM_SMCCC_OWNER_STANDARD	4
> +#define ARM_SMCCC_SMC_32		0
> +#define ARM_SMCCC_SMC_64		1
> +#define ARM_SMCCC_TYPE_SHIFT		31
> +#define ARM_SMCCC_CALL_CONV_SHIFT	30
> +#define ARM_SMCCC_OWNER_MASK		0x3f
> +#define ARM_SMCCC_OWNER_SHIFT		24
> +#define ARM_SMCCC_FUNC_MASK		0xffff
> +
> +#define ARM_SMCCC_CALL_VAL(type, calling_convention, owner, func_num) \
> +	(((type) << ARM_SMCCC_TYPE_SHIFT) | \
> +	((calling_convention) << ARM_SMCCC_CALL_CONV_SHIFT) | \
> +	(((owner) & ARM_SMCCC_OWNER_MASK) << ARM_SMCCC_OWNER_SHIFT) | \
> +	((func_num) & ARM_SMCCC_FUNC_MASK))
> +
> +#else
> +/* CONFIG_ARM64 */
> +#include <linux/arm-smccc.h>
> +typedef struct arm_smccc_1_2_regs ffa_value_t;
> +#endif
> +
> +/* Defining the function pointer type for the function executing the FF-A ABIs */
> +typedef void (*invoke_ffa_fn_t)(ffa_value_t args, ffa_value_t *res);
> +
> +/* FF-A driver version definitions */
> +
> +#define MAJOR_VERSION_MASK		GENMASK(30, 16)
> +#define MINOR_VERSION_MASK		GENMASK(15, 0)
> +#define GET_FFA_MAJOR_VERSION(x)		\
> +				((u16)(FIELD_GET(MAJOR_VERSION_MASK, (x))))
> +#define GET_FFA_MINOR_VERSION(x)		\
> +				((u16)(FIELD_GET(MINOR_VERSION_MASK, (x))))
> +#define PACK_VERSION_INFO(major, minor)			\
> +	(FIELD_PREP(MAJOR_VERSION_MASK, (major)) |	\
> +	 FIELD_PREP(MINOR_VERSION_MASK, (minor)))
> +
> +#define FFA_MAJOR_VERSION		(1)
> +#define FFA_MINOR_VERSION		(0)
> +#define FFA_VERSION_1_0		\
> +			PACK_VERSION_INFO(FFA_MAJOR_VERSION, FFA_MINOR_VERSION)
> +
> +/* Endpoint ID mask (u-boot endpoint ID) */
> +
> +#define GET_SELF_ENDPOINT_ID_MASK		GENMASK(15, 0)
> +#define GET_SELF_ENDPOINT_ID(x)		\
> +			((u16)(FIELD_GET(GET_SELF_ENDPOINT_ID_MASK, (x))))
> +
> +#define PREP_SELF_ENDPOINT_ID_MASK		GENMASK(31, 16)
> +#define PREP_SELF_ENDPOINT_ID(x)		\
> +			(FIELD_PREP(PREP_SELF_ENDPOINT_ID_MASK, (x)))
> +
> +/* Partition endpoint ID mask  (partition with which u-boot communicates with) */
> +
> +#define PREP_PART_ENDPOINT_ID_MASK		GENMASK(15, 0)
> +#define PREP_PART_ENDPOINT_ID(x)		\
> +			(FIELD_PREP(PREP_PART_ENDPOINT_ID_MASK, (x)))
> +
> +/* Definitions of the Arm FF-A interfaces supported by the Arm FF-A driver */
> +
> +#define FFA_SMC(calling_convention, func_num)				\
> +	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, (calling_convention),	\
> +			   ARM_SMCCC_OWNER_STANDARD, (func_num))
> +
> +#define FFA_SMC_32(func_num)				FFA_SMC(ARM_SMCCC_SMC_32, (func_num))
> +#define FFA_SMC_64(func_num)				FFA_SMC(ARM_SMCCC_SMC_64, (func_num))
> +
> +enum ffa_abis {
> +	FFA_ERROR                 = 0x60,
> +	FFA_SUCCESS               = 0x61,
> +	FFA_INTERRUPT             = 0x62,
> +	FFA_VERSION               = 0x63,
> +	FFA_FEATURES              = 0x64,
> +	FFA_RX_RELEASE            = 0x65,
> +	FFA_RXTX_MAP              = 0x66,
> +	FFA_RXTX_UNMAP            = 0x67,
> +	FFA_PARTITION_INFO_GET    = 0x68,
> +	FFA_ID_GET                = 0x69,
> +	FFA_RUN                   = 0x6d,
> +	FFA_MSG_SEND_DIRECT_REQ   = 0x6f,
> +	FFA_MSG_SEND_DIRECT_RESP  = 0x70,
> +
> +	/* To be updated when adding new FFA IDs */
> +	FFA_FIRST_ID              = FFA_ERROR, /* Lowest number ID */
> +	FFA_LAST_ID               = FFA_MSG_SEND_DIRECT_RESP, /* Highest number ID */
> +};
> +
> +enum ffa_abi_errcode {
> +	NOT_SUPPORTED = 1,
> +	INVALID_PARAMETERS,
> +	NO_MEMORY,
> +	BUSY,
> +	INTERRUPTED,
> +	DENIED,
> +	RETRY,
> +	ABORTED,
> +	MAX_NUMBER_FFA_ERR
> +};
> +
> +extern int ffa_to_std_errmap[MAX_NUMBER_FFA_ERR];
> +
> +/* Container structure and helper macros to map between an FF-A error and relevant error log */
> +struct ffa_abi_errmap {
> +	char *err_str[MAX_NUMBER_FFA_ERR];
> +};
> +
> +#define FFA_ERRMAP_COUNT (FFA_LAST_ID - FFA_FIRST_ID + 1)
> +#define FFA_ID_TO_ERRMAP_ID(ffa_id) ((ffa_id) - FFA_FIRST_ID)
> +
> +/**
> + * enum ffa_rxtx_buf_sizes - minimum sizes supported
> + * for the RX/TX buffers
> + */
> +enum ffa_rxtx_buf_sizes {
> +	RXTX_4K,
> +	RXTX_64K,
> +	RXTX_16K
> +};
> +
> +/**
> + * struct ffa_rxtxpair - Hosts the RX/TX buffers virtual addresses
> + * @rxbuf:	virtual address of the RX buffer
> + * @txbuf:	virtual address of the TX buffer
> + * @rxtx_min_pages:	RX/TX buffers minimum size in pages
> + *
> + * Hosts the virtual addresses of the mapped RX/TX buffers
> + * These addresses are used by the FF-A functions that use the RX/TX buffers
> + */
> +struct ffa_rxtxpair {
> +	void *rxbuf; /* Virtual address returned by memalign */
> +	void *txbuf; /* Virtual address returned by memalign */
> +	size_t rxtx_min_pages; /* Minimum number of pages in each of the RX/TX buffers */
> +};
> +
> +struct ffa_partition_desc;
> +
> +/**
> + * struct ffa_partitions - descriptors for all secure partitions
> + * @count:	The number of partitions descriptors
> + * @descs	The partitions descriptors table
> + *
> + * Contains the partitions descriptors table
> + */
> +struct ffa_partitions {
> +	u32 count;
> +	struct ffa_partition_desc *descs; /* Virtual address */
> +};
> +
> +/**
> + * struct ffa_priv - the driver private data structure
> + *
> + * @fwk_version:	FF-A framework version
> + * @emul:	FF-A sandbox emulator
> + * @id:	u-boot endpoint ID
> + * @partitions:	The partitions descriptors structure
> + * @pair:	The RX/TX buffers pair
> + *
> + * The device private data structure containing all the
> + * data read from secure world.
> + */
> +struct ffa_priv {
> +	u32 fwk_version;
> +	struct udevice *emul;
> +	u16 id;
> +	struct ffa_partitions partitions;
> +	struct ffa_rxtxpair pair;
> +};
> +
> +/**
> + * ffa_get_version_hdlr() - FFA_VERSION handler function
> + * @dev: The FF-A bus device
> + *
> + * Implement FFA_VERSION FF-A function
> + * to get from the secure world the FF-A framework version
> + * FFA_VERSION is used to discover the FF-A framework.
> + *
> + * Return:
> + *
> + * 0 on success. Otherwise, failure
> + */
> +int ffa_get_version_hdlr(struct udevice *dev);
> +
> +/**
> + * invoke_ffa_fn() - SMC wrapper
> + * @args: FF-A ABI arguments to be copied to Xn registers
> + * @res: FF-A ABI return data to be copied from Xn registers
> + *
> + * Calls low level SMC implementation.
> + * This function should be implemented by the user driver.
> + */
> +void invoke_ffa_fn(ffa_value_t args, ffa_value_t *res);
> +
> +#endif
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 307ad6931c..3c6af2e3d2 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -4,6 +4,11 @@
>   *
>   * (C) Copyright 2012
>   * Pavel Herrmann <morpheus.ibis at gmail.com>
> + *
> + * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office at arm.com>
> + *
> + * Authors:
> + *   Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
>   */
>  
>  #ifndef _DM_UCLASS_ID_H
> @@ -57,6 +62,7 @@ enum uclass_id {
>  	UCLASS_ETH,		/* Ethernet device */
>  	UCLASS_ETH_PHY,		/* Ethernet PHY device */
>  	UCLASS_EXTCON,		/* External Connector Class */
> +	UCLASS_FFA,		/* Arm Firmware Framework for Armv8-A */
>  	UCLASS_FIRMWARE,	/* Firmware */
>  	UCLASS_FPGA,		/* FPGA device */
>  	UCLASS_FUZZING_ENGINE,	/* Fuzzing engine */
> -- 
> 2.25.1
> 
Acked-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>



More information about the U-Boot mailing list