| Message ID | 20230705172759.1610753-1-gatien.chevallier@foss.st.com |
|---|---|
| Headers | show |
| Series | Introduce STM32 Firewall framework | expand |
Hello Krzysztof, On 7/6/23 11:29, Gatien CHEVALLIER wrote: > Hello Krzysztof, > > Firstly, I will correct the bindings error pointed by Rob's robot. > Obviously, I did not pass the bindings check the proper way or maybe I'm > running an old version. > > On 7/6/23 08:28, Krzysztof Kozlowski wrote: >> On 05/07/2023 19:27, Gatien Chevallier wrote: >>> Document RIFSC (RIF security controller). RIFSC is a firewall controller >>> composed of different kinds of hardware resources. >>> >>> Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com> >> >> A nit, subject: drop second/last, redundant "device tree bindings for". >> The "dt-bindings" prefix is already stating that these are bindings. 4 >> words of your 6 word subject is meaningless... > > Ack, I will rephrase, it is indeed redundant > >> >>> --- >>> .../bindings/bus/st,stm32-rifsc.yaml | 101 ++++++++++++++++++ >>> 1 file changed, 101 insertions(+) >>> create mode 100644 >>> Documentation/devicetree/bindings/bus/st,stm32-rifsc.yaml >>> >>> diff --git >>> a/Documentation/devicetree/bindings/bus/st,stm32-rifsc.yaml >>> b/Documentation/devicetree/bindings/bus/st,stm32-rifsc.yaml >>> new file mode 100644 >>> index 000000000000..68d585ed369c >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/bus/st,stm32-rifsc.yaml >> >> Filename like compatible, unless you know list of compatibles will >> grow... but then add them. >> >>> @@ -0,0 +1,101 @@ >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>> +%YAML 1.2 >>> +--- >>> +$id: http://devicetree.org/schemas/bus/st,stm32-rifsc.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> + >>> +title: STM32 Resource isolation framework security controller bindings >> >> Drop bindings > > Ack > >> >>> + >>> +maintainers: >>> + - Gatien Chevallier <gatien.chevallier@foss.st.com> >>> + >>> +description: | >>> + Resource isolation framework (RIF) is a comprehensive set of >>> hardware blocks >>> + designed to enforce and manage isolation of STM32 hardware >>> resources like >>> + memory and peripherals. >>> + >>> + The RIFSC (RIF security controller) is composed of three sets of >>> registers, >>> + each managing a specific set of hardware resources: >>> + - RISC registers associated with RISUP logic (resource isolation >>> device unit >>> + for peripherals), assign all non-RIF aware peripherals to >>> zero, one or >>> + any security domains (secure, privilege, compartment). >>> + - RIMC registers: associated with RIMU logic (resource isolation >>> master >>> + unit), assign all non RIF-aware bus master to one security >>> domain by >>> + setting secure, privileged and compartment information on the >>> system bus. >>> + Alternatively, the RISUP logic controlling the device port >>> access to a >>> + peripheral can assign target bus attributes to this peripheral >>> master port >>> + (supported attribute: CID). >>> + - RISC registers associated with RISAL logic (resource isolation >>> device unit >>> + for address space - Lite version), assign address space >>> subregions to one >>> + security domains (secure, privilege, compartment). >>> + >>> +properties: >>> + compatible: >>> + const: st,stm32mp25-rifsc >>> + >>> + reg: >>> + maxItems: 1 >>> + >>> + "#address-cells": >>> + const: 1 >>> + >>> + "#size-cells": >>> + const: 1 >>> + >>> + "#feature-domain-cells": >>> + const: 1 >>> + >>> + ranges: true >>> + >>> + feature-domain-controller: true >>> + >>> +patternProperties: >>> + "^.*@[0-9a-f]+$": >>> + description: Peripherals >>> + type: object >>> + properties: >>> + feature-domains: >>> + minItems: 1 >>> + maxItems: 2 >>> + description: >>> + The first argument must always be a phandle that >>> references to the >>> + firewall controller of the peripheral. The second can >>> contain the >>> + platform specific firewall ID of the peripheral. >> >> It does not make much sense to me to have hierarchy parent-child and via >> phandle at the same time. You express the similar relationship twice > Thank you for pointing this out. > > About the parent-child relation: > > The bus-like device tree architecture allows a bus-probe mechanism with > which we want to check accesses of peripherals before probing their > driver. This has several advantages: > -This bus architecture provides a clearer view of the hardware. > -No peripheral driver modifications as it is fully handled by the > firewall drivers. > -Drivers for devices that aren't accessible will not even be probed => > no probe fail. > > It would be possible to manage this mechanism another way by handling > probe deferrals in drivers. But it would mean modifying every driver > with a check on ST firewall that we probe and some of them aren't from > STMicroelectronics. > > About the phandle relation: > > I agree on the fact that this double expression of the relationship is > redundant. > > I've done it this way because there will be other nodes outside the > RIFSC node that will need to reference it as their feature-domain > controller. I kept the same information in the property to be coherent > between all. > > For nodes under the RIFSC, the phandle is indeed useless and could be > removed, just to leave the firewall ID. And I'm inclined to do so. I > just have one worry on the YAML binding files where I will have a > pattern property in the RIFSC that will state something and maybe > another description in the peripheral YAML files. What is your take on > that? > Looking back at it, feature-domains is a phandle-array. I guess I can't derogate to the following architecture: items: - items: - description: A phandle - description: 1st arg cell - description: 2nd arg cell can I? Some devices' nodes that are not subnodes of the firewall controllers will need the phandle reference. Should I keep the redundant information then? Best regards, Gatien >> >>> + >>> +required: >>> + - compatible >>> + - reg >>> + - "#address-cells" >>> + - "#size-cells" >>> + - feature-domain-controller >>> + - "#feature-domain-cells" >>> + - ranges >>> + >>> +additionalProperties: false >>> + >>> +examples: >>> + - | >>> + // In this example, the usart2 device refers to rifsc as its domain >>> + // controller. >>> + // Access rights are verified before creating devices. >>> + >>> + #include <dt-bindings/interrupt-controller/arm-gic.h> >>> + >>> + rifsc: rifsc-bus@42080000 { >>> + compatible = "st,stm32mp25-rifsc"; >>> + reg = <0x42080000 0x1000>; >>> + #address-cells = <1>; >>> + #size-cells = <1>; >>> + ranges; >>> + feature-domain-controller; >>> + #feature-domain-cells = <1>; >>> + >>> + usart2: serial@400e0000 { >>> + compatible = "st,stm32h7-uart"; >>> + reg = <0x400e0000 0x400>; >>> + interrupts = <GIC_SPI 115 IRQ_TYPE_LEVEL_HIGH>; >>> + clocks = <&ck_flexgen_08>; >>> + feature-domains = <&rifsc 32>; >>> + status = "disabled"; >> >> No status in the examples. >> >>> + }; >>> + }; >> >> Best regards, >> Krzysztof >> > > Best regards, > Gatien
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. Oleksii Moisieiev (1): dt-bindings: Document common device controller bindings Gatien Chevallier (9): dt-bindings: bus: add device tree bindings for RIFSC dt-bindings: bus: add device tree bindings for ETZPC dt-bindings: treewide: add feature-domains description in binding files firewall: introduce stm32_firewall framework 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 | 90 + .../bindings/bus/st,stm32-rifsc.yaml | 101 + .../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 + .../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 | 5 +- drivers/bus/Kconfig | 10 + drivers/bus/Makefile | 1 + drivers/bus/stm32_etzpc.c | 137 + drivers/bus/stm32_firewall.c | 252 ++ drivers/bus/stm32_firewall.h | 83 + drivers/bus/stm32_rifsc.c | 248 ++ include/linux/bus/stm32_firewall_device.h | 134 + 44 files changed, 3276 insertions(+), 1918 deletions(-) create mode 100644 Documentation/devicetree/bindings/bus/st,stm32-etzpc.yaml create mode 100644 Documentation/devicetree/bindings/bus/st,stm32-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