2023-09-26 00:36:46

by Gatien CHEVALLIER

[permalink] [raw]
Subject: Re: [PATCH v3 00/11] Introduce STM32 Firewall framework

Hello all,

Since the "feature-domains" bindings lacks precision (maybe some
renaming for better clarity on its purpose), I will send v4 with a
vendor binding so the generic one better discussed and enriched with
other contributor examples.

This will avoid mixing several patch set.

Best regards,
Gatien

On 7/26/23 10:37, Gatien Chevallier wrote:
> Introduce STM32 Firewall framework for STM32MP1x and STM32MP2x
> platforms. STM32MP1x(ETZPC) and STM32MP2x(RIFSC) Firewall controllers
> register to the framework to offer firewall services such as access
> granting.
>
> This series of patches is a new approach on the previous STM32 system
> bus, history is available here:
> https://lore.kernel.org/lkml/20230127164040.1047583/
>
> The need for such framework arises from the fact that there are now
> multiple hardware firewalls implemented across multiple products.
> Drivers are shared between different products, using the same code.
> When it comes to firewalls, the purpose mostly stays the same: Protect
> hardware resources. But the implementation differs, and there are
> multiple types of firewalls: peripheral, memory, ...
>
> Some hardware firewall controllers such as the RIFSC implemented on
> STM32MP2x platforms may require to take ownership of a resource before
> being able to use it, hence the requirement for firewall services to
> take/release the ownership of such resources.
>
> On the other hand, hardware firewall configurations are becoming
> more and more complex. These mecanisms prevent platform crashes
> or other firewall-related incoveniences by denying access to some
> resources.
>
> The stm32 firewall framework offers an API that is defined in
> firewall controllers drivers to best fit the specificity of each
> firewall.
>
> For every peripherals protected by either the ETZPC or the RIFSC, the
> firewall framework checks the firewall controlelr registers to see if
> the peripheral's access is granted to the Linux kernel. If not, the
> peripheral is configured as secure, the node is marked populated,
> so that the driver is not probed for that device.
>
> The firewall framework relies on the feature-domain-controller device
> tree bindings: https://lore.kernel.org/lkml/0c0a82bb-18ae-d057-562b.
> It is used by peripherals to reference a domain controller, in this
> case a firewall feature domain. The bus uses the ID referenced by
> the feature-domains property to know where to look in the firewall
> to get the security configuration for the peripheral. This allows
> a device tree description rather than a hardcoded peripheral table
> in the bus driver.
>
> The STM32 ETZPC device is responsible for filtering accesses based on
> security level, or co-processor isolation for any resource connected
> to it.
>
> The RIFSC is responsible for filtering accesses based on Compartment
> ID / security level / privilege level for any resource connected to
> it.
>
> STM32MP13/15/25 SoC device tree files are updated in this series to
> implement this mecanism.
>
> Changes in V2:
>
> generic:
> - Add fw_devlink dependency for "feature-domains"
> property.
>
> bindings:
> - Corrected YAMLS errors highlighted by Rob's robot
> - Firewall controllers YAMLs no longer define the
> maxItems for the "feature-domains" property
> - Renamed st,stm32-rifsc.yaml to
> st,stm32mp25-rifsc.yaml
> - Fix examples in YAML files
> - Change feature-domains maxItems to 2 in firewall
> consumer files as there should not be more than
> 2 entries for now
> - Declare "feature-domain-names" as an optional
> property for firewall controllers child nodes.
> - Add missing "feature-domains" property declaration
> in bosch,m_can.yaml and st,stm32-cryp.yaml files
>
> firewall framework:
> - Support multiple entries for "feature-domains"
> property
> - Better handle the device-tree parsing using
> phandle+args APIs
> - Remove "resource firewall" type
> - Add a field for the name of the firewall entry
> - Fix licenses
>
> RIFSC:
> - Add controller name
> - Driver is now a module_platform_driver
> - Fix license
>
> ETZPC:
> - Add controller name
> - Driver is now a module_platform_driver
> - Fix license
>
> Device trees:
> - Fix rifsc node name
> - Move the "ranges" property under the
> "feature-domains" one
>
> Changes in V3:
>
> Change incorrect ordering for bindings commits leading
> to an error while running
> "make DT_CHECKER_FLAGS=-m dt_binding_check"
>
> Oleksii Moisieiev (1):
> dt-bindings: Document common device controller bindings
>
> Gatien Chevallier (10):
> dt-bindings: treewide: add feature-domains description
> dt-bindings: bus: document RIFSC
> dt-bindings: bus: document ETZPC
> firewall: introduce stm32_firewall framework
> of: property: fw_devlink: Add support for "feature-domains"
> bus: rifsc: introduce RIFSC firewall controller driver
> arm64: dts: st: add RIFSC as a domain controller for STM32MP25x boards
> bus: etzpc: introduce ETZPC firewall controller driver
> ARM: dts: stm32: add ETZPC as a system bus for STM32MP15x boards
> ARM: dts: stm32: add ETZPC as a system bus for STM32MP13x boards
>
> .../bindings/bus/st,stm32-etzpc.yaml | 96 +
> .../bindings/bus/st,stm32mp25-rifsc.yaml | 105 +
> .../bindings/crypto/st,stm32-cryp.yaml | 4 +
> .../bindings/crypto/st,stm32-hash.yaml | 4 +
> .../devicetree/bindings/dma/st,stm32-dma.yaml | 4 +
> .../bindings/dma/st,stm32-dmamux.yaml | 4 +
> .../feature-domain-controller.yaml | 84 +
> .../devicetree/bindings/i2c/st,stm32-i2c.yaml | 4 +
> .../bindings/iio/adc/st,stm32-adc.yaml | 4 +
> .../bindings/iio/adc/st,stm32-dfsdm-adc.yaml | 4 +
> .../bindings/iio/dac/st,stm32-dac.yaml | 4 +
> .../bindings/media/cec/st,stm32-cec.yaml | 4 +
> .../bindings/media/st,stm32-dcmi.yaml | 4 +
> .../memory-controllers/st,stm32-fmc2-ebi.yaml | 4 +
> .../bindings/mfd/st,stm32-lptimer.yaml | 4 +
> .../bindings/mfd/st,stm32-timers.yaml | 5 +
> .../devicetree/bindings/mmc/arm,pl18x.yaml | 4 +
> .../bindings/net/can/bosch,m_can.yaml | 4 +
> .../devicetree/bindings/net/stm32-dwmac.yaml | 4 +
> .../bindings/phy/phy-stm32-usbphyc.yaml | 4 +
> .../bindings/regulator/st,stm32-vrefbuf.yaml | 4 +
> .../devicetree/bindings/rng/st,stm32-rng.yaml | 4 +
> .../bindings/serial/st,stm32-uart.yaml | 4 +
> .../bindings/sound/st,stm32-i2s.yaml | 4 +
> .../bindings/sound/st,stm32-sai.yaml | 4 +
> .../bindings/sound/st,stm32-spdifrx.yaml | 4 +
> .../bindings/spi/st,stm32-qspi.yaml | 4 +
> .../devicetree/bindings/spi/st,stm32-spi.yaml | 4 +
> .../devicetree/bindings/usb/dwc2.yaml | 4 +
> MAINTAINERS | 7 +
> arch/arm/boot/dts/st/stm32mp131.dtsi | 1027 +++---
> arch/arm/boot/dts/st/stm32mp133.dtsi | 51 +-
> arch/arm/boot/dts/st/stm32mp13xc.dtsi | 19 +-
> arch/arm/boot/dts/st/stm32mp13xf.dtsi | 19 +-
> arch/arm/boot/dts/st/stm32mp151.dtsi | 2757 +++++++++--------
> arch/arm/boot/dts/st/stm32mp153.dtsi | 52 +-
> arch/arm/boot/dts/st/stm32mp15xc.dtsi | 19 +-
> arch/arm64/Kconfig.platforms | 1 +
> arch/arm64/boot/dts/st/stm32mp251.dtsi | 7 +-
> drivers/bus/Kconfig | 9 +
> drivers/bus/Makefile | 1 +
> drivers/bus/stm32_etzpc.c | 141 +
> drivers/bus/stm32_firewall.c | 288 ++
> drivers/bus/stm32_firewall.h | 83 +
> drivers/bus/stm32_rifsc.c | 252 ++
> drivers/of/property.c | 2 +
> include/linux/bus/stm32_firewall_device.h | 140 +
> 47 files changed, 3346 insertions(+), 1919 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/bus/st,stm32-etzpc.yaml
> create mode 100644 Documentation/devicetree/bindings/bus/st,stm32mp25-rifsc.yaml
> create mode 100644 Documentation/devicetree/bindings/feature-controllers/feature-domain-controller.yaml
> create mode 100644 drivers/bus/stm32_etzpc.c
> create mode 100644 drivers/bus/stm32_firewall.c
> create mode 100644 drivers/bus/stm32_firewall.h
> create mode 100644 drivers/bus/stm32_rifsc.c
> create mode 100644 include/linux/bus/stm32_firewall_device.h
>