[PATCH v11 00/10] introduce Arm FF-A support

Abdellatif El Khlifi
2023-04-12T09:43:09Z

Adding support for Arm FF-A v1.0 (Arm Firmware Framework for Armv8-A) [A].

FF-A describes interfaces (ABIs) that standardize communication
between the Secure World and Normal World. These interfaces enable a pair of
software sandboxes to communicate with each other. A sandbox aka partition could
be a VM in the Normal or Secure world, an application in S-EL0, or a
Trusted OS in S-EL1.

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.

=> dm tree

Class Index Probed Driver Name
-----------------------------------------------------------
...
firmware 0 [ + ] psci |-- psci
ffa 0 [ ] arm_ffa | `-- arm_ffa
...

Clients are able to probe then use the FF-A bus by calling the DM class
searching APIs (e.g: uclass_get_device_by_name).

This implementation of the specification provides support for Aarch64.

The FF-A driver uses the SMC ABIs defined by the FF-A specification to:

- Discover the presence of secure partitions (SPs) of interest
- Access an SP's service through communication protocols
e.g. EFI MM communication protocol

The FF-A support provides the following features:

- Being generic by design and can be used by any Arm 64-bit platform
- A Uclass driver providing generic FF-A methods and driver operations
- An Arm FF-A device driver
- FF-A support can be compiled and used without EFI
- Support for SMCCCv1.2 x0-x17 registers
- Support for SMC32 calling convention
- Support for 32-bit and 64-bit FF-A direct messaging
- A new command called armffa is provided as an example of how to access the
FF-A bus
- Support for FF-A MM communication (compatible with EFI boot time)
- Enabling FF-A and MM communication in Corstone1000 platform as a use case
- A sandbox emulator for Arm FF-A
- An FF-A sandbox device driver
- Sandbox FF-A test cases

For more details about the FF-A support please refer to [B] and refer to [C] for
how to use the armffa command.

Please find at [D] an example of the expected boot logs when enabling
FF-A support for a platform. In this example the platform is
Corstone1000. But it can be any Arm 64-bit platform.

Changelog of the major changes:
===========================

v11:

* move ffa_try_discovery() from the uclass to the Arm FF-A driver
* rename ffa_try_discovery() to arm_ffa_discover()
* add arm_ prefix to the Arm FF-A driver functions
* use U_BOOT_CMD_WITH_SUBCMDS for armffa command
* store the sandbox emulator pointer in the FF-A device uc_priv (struct ffa_priv)
* set the emulator as parent of the sandbox FF-A device
* rename select_ffa_mm_comms() to select_mm_comms()
* improve the logic of MM transport selection in mm_communicate()
* use ut_asserteq_mem() in uuid_str_to_le_bin test case
* address nits

v10: [10]

* provide the FF-A driver operations through the Uclass (arm-ffa-uclass.c)
* move the generic FF-A methods to the Uclass
* keep Arm specific methods in the Arm driver (arm-ffa.c renamed from core.c)
* split the FF-A sandbox support into an emulator (ffa-emul-uclass.c) and a driver (sandbox_ffa.c)
* use the FF-A driver Uclass operations by clients (armffa command, tests, MM comms)
* use uclass_first_device to search and probe the FF-A device (whether it is on Arm or on sandbox)
* address nits

v9: [9]

* integrate the FF-A bus discovery in the DM and use ARM_SMCCC_FEATURES for binding
* align FF-A sandbox driver with FF-A discovery through DM
* use DM class APIs to probe and interact with the FF-A bus (in FF-A MM comms, armffa command, sandbox tests)
* add documentation for the armffa command: doc/usage/cmd/armffa.rst
* introduce testcase for uuid_str_to_le_bin

v8: [8]

* pass the FF-A bus device to the bus operations
* isolate the compilation choices between FF-A and OP-TEE
* drop OP-TEE configs from Corstone-1000 defconfig
* make ffa_get_partitions_info() second argument to be an SP count in both
modes

v7: [7]

* add support for 32-bit direct messaging (now we have 32-bit and 64-bit support)
* set the MM door bell event to use 64-bit direct messaging
* issue a compile time error when one of these macros are not found :
FFA_SHARED_MM_BUFFER_SIZE, FFA_SHARED_MM_BUFFER_OFFSET, FFA_SHARED_MM_BUFFER_ADDR
* make uuid_str_to_le_bin() implementation similar to uuid_str_to_bin()
by using same APIs

v6: [6]

* remove clearing x0-x17 registers after SMC calls
* drop use of EFI runtime support for FF-A (We decided with Linaro to add this later)
* drop discovery from initcalls (discovery will be on demand by FF-A users)
* add FF-A runtime discovery at MM communication level
* update the documentation and move it to doc/arch/arm64.ffa.rst

v5: [5]

* move changelogs in each commit to the changes section

v4: [4]

* add FF-A support README (doc/README.ffa.drv)
* improving error handling by mapping the FF-A errors to standard errors
and logs
* replacing panics with an error log
* align sandbox driver and tests with the new FF-A driver interfaces
and new way of error handling
* use the new FF-A driver interfaces for MM communication
* discover MM partitions at runtime
* copy FF-A driver private data to EFI runtime section at
ExitBootServices()
* moving the FF-A driver work to drivers/firmware/arm-ffa
* improving features discovery in FFA_FEATURES
* add remove/unbind functions to the FF-A core device
* improve how the driver behaves when bus discovery is done more than
once
* move clearing x0-x17 registers code into a new macro like done in
the linux kernel
* enable EFI MM communication for the Corstone1000 platform

v3: [3]

* port x0-x17 registers support from linux kernel as defined by
SMCCCv1.2
* 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}
* update armffa command with the new driver interfaces

v2 [2]:

* make FF-A bus discoverable using device_{bind, probe} APIs
* remove device tree support

v1 [1]:

* introduce FF-A bus driver with device tree support
* introduce armffa command
* introduce FF-A Sandbox driver
* add FF-A Sandbox test cases
* introduce FF-A MM communication

Cheers,
Abdellatif

List of previous patches:

[1]: https://lore.kernel.org/all/20220329151659.16894-1-abdellatif.elkhlifi@arm.com/
[2]: https://lore.kernel.org/all/20220415122803.16666-1-abdellatif.elkhlifi@arm.com/
[3]: https://lore.kernel.org/all/20220801172053.20163-1-abdellatif.elkhlifi@arm.com/
[4]: https://lore.kernel.org/all/20220926101723.9965-1-abdellatif.elkhlifi@arm.com/
[5]: https://lore.kernel.org/all/20220926140827.15125-1-abdellatif.elkhlifi@arm.com/
[6]: https://lore.kernel.org/all/20221013103857.614-1-abdellatif.elkhlifi@arm.com/
[7]: https://lore.kernel.org/all/20221107192055.21669-1-abdellatif.elkhlifi@arm.com/
[8]: https://lore.kernel.org/all/20221122131751.22747-1-abdellatif.elkhlifi@arm.com/
[9]: https://lore.kernel.org/all/20230310141016.137986-1-abdellatif.elkhlifi@arm.com/
[10]: https://lore.kernel.org/all/20230328161157.219375-1-abdellatif.elkhlifi@arm.com/

More details:

[A]: https://developer.arm.com/documentation/den0077/latest/
[B]: doc/arch/arm64.ffa.rst
[C]: doc/usage/cmd/armffa.rst
[D]: example of boot logs when enabling FF-A

```
U-Boot 2023.01 (Mar 27 2023 - 13:48:33 +0000) corstone1000 aarch64

DRAM: 2 GiB
Arm FF-A framework discovery
Using Arm SMC for FF-A conduit
FF-A driver 1.0
FF-A framework 1.0
FF-A versions are compatible
...
Hit any key to stop autoboot: 0
Loading kernel from 0x083EE000 to memory ...
...
FF-A endpoint ID is 0
Using 1 4KB page(s) for FF-A RX/TX buffers size
FF-A RX buffer at virtual address 00000000fdf4f000
FF-A TX buffer at virtual address 00000000fdf51000
FF-A RX/TX buffers mapped
Reading FF-A partitions data from the RX buffer
FF-A partition ID 8001 : info cached
FF-A partition ID 8002 : info cached
FF-A partition ID 8003 : info cached
3 FF-A partition(s) found and cached
Preparing for checking FF-A partitions count
Searching FF-A partitions using the provided UUID
No FF-A partition found. Querying framework ...
Reading FF-A partitions data from the RX buffer
Number of FF-A partition(s) matching the UUID: 1
EFI: Pre-allocating 1 partition(s) info structures
Preparing for filling FF-A partitions info
Searching FF-A partitions using the provided UUID
FF-A partition ID 8003 matches the provided UUID
EFI: MM partition ID 0x8003
EFI: Corstone1000: Capsule shared buffer at 0x80000000 , size 8192 pages
Booting /MemoryMapped(0x0,0x88200000,0xf00000)
EFI stub: Booting Linux Kernel...
EFI stub: Using DTB from configuration table
EFI stub: Exiting boot services...
unmapping FF-A RX/TX buffers
Freeing FF-A RX/TX buffers
Booting Linux on physical CPU 0x0000000000 [0x411fd040]
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
```

Cc: Tom Rini <trini@konsulko.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Achin Gupta <achin.gupta@arm.com>
Cc: Drew Reed <Drew.Reed@arm.com>
Cc: Xueliang Zhong <Xueliang.Zhong@arm.com>

Abdellatif El Khlifi (10):
arm64: smccc: add support for SMCCCv1.2 x0-x17 registers
lib: uuid: introduce uuid_str_to_le_bin function
lib: uuid: introduce testcase for uuid_str_to_le_bin
arm_ffa: introduce Arm FF-A support
arm_ffa: introduce armffa command
arm_ffa: introduce sandbox FF-A support
arm_ffa: introduce sandbox test cases for UCLASS_FFA
arm_ffa: introduce armffa command Sandbox test
arm_ffa: efi: introduce FF-A MM communication
arm_ffa: efi: corstone1000: enable MM communication

MAINTAINERS | 18 +
arch/arm/cpu/armv8/smccc-call.S | 57 +-
arch/arm/lib/asm-offsets.c | 16 +
arch/sandbox/dts/sandbox.dtsi | 8 +
arch/sandbox/dts/test.dts | 8 +
arch/sandbox/include/asm/sandbox_arm_ffa.h | 72 ++
.../include/asm/sandbox_arm_ffa_priv.h | 133 ++
cmd/Kconfig | 10 +
cmd/Makefile | 2 +
cmd/armffa.c | 212 +++
configs/corstone1000_defconfig | 2 +
configs/sandbox64_defconfig | 1 +
configs/sandbox_defconfig | 1 +
doc/arch/arm64.ffa.rst | 294 +++++
doc/arch/index.rst | 1 +
doc/arch/sandbox/sandbox.rst | 1 +
doc/usage/cmd/armffa.rst | 105 ++
doc/usage/index.rst | 1 +
drivers/Makefile | 1 +
drivers/firmware/Kconfig | 1 +
drivers/firmware/arm-ffa/Kconfig | 42 +
drivers/firmware/arm-ffa/Makefile | 16 +
drivers/firmware/arm-ffa/arm-ffa-uclass.c | 1143 +++++++++++++++++
drivers/firmware/arm-ffa/arm-ffa.c | 127 ++
drivers/firmware/arm-ffa/ffa-emul-uclass.c | 738 +++++++++++
drivers/firmware/arm-ffa/sandbox_ffa.c | 119 ++
include/arm_ffa.h | 217 ++++
include/arm_ffa_priv.h | 271 ++++
include/configs/corstone1000.h | 15 +-
include/dm/uclass-id.h | 7 +
include/linux/arm-smccc.h | 45 +
include/mm_communication.h | 13 +
include/uuid.h | 15 +
lib/efi_loader/Kconfig | 14 +-
lib/efi_loader/efi_variable_tee.c | 312 ++++-
lib/uuid.c | 48 +
test/cmd/Makefile | 2 +
test/cmd/armffa.c | 39 +
test/dm/Makefile | 2 +
test/dm/ffa.c | 258 ++++
test/lib/Makefile | 1 +
test/lib/uuid.c | 41 +
42 files changed, 4420 insertions(+), 9 deletions(-)
create mode 100644 arch/sandbox/include/asm/sandbox_arm_ffa.h
create mode 100644 arch/sandbox/include/asm/sandbox_arm_ffa_priv.h
create mode 100644 cmd/armffa.c
create mode 100644 doc/arch/arm64.ffa.rst
create mode 100644 doc/usage/cmd/armffa.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/ffa-emul-uclass.c
create mode 100644 drivers/firmware/arm-ffa/sandbox_ffa.c
create mode 100644 include/arm_ffa.h
create mode 100644 include/arm_ffa_priv.h
create mode 100644 test/cmd/armffa.c
create mode 100644 test/dm/ffa.c
create mode 100644 test/lib/uuid.c

--
2.25.1