Messages in this thread | | | Date | Mon, 8 Apr 2024 10:42:59 +0200 | Subject | Re: [PATCH v9 00/13] Introduce STM32 Firewall framework | From | Alexandre TORGUE <> |
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Hi Gatien,
On 1/5/24 14:03, 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 access-controller device tree > binding. It is used by peripherals to reference a domain access > controller. In this case a firewall controller. The bus uses the ID > referenced by the access-controller 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. >
..
After minor cosmetic fixes, series applied on stm32-next. Seen with Arnd: it will be part on my next PR and will come through arm-soc tree.
Thanks Alex
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