arm_ffa: introduce Arm FF-A support
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@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/drivers/firmware/arm-ffa/Kconfig b/drivers/firmware/arm-ffa/Kconfig
new file mode 100644
index 0000000..9200c80
--- /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
+