AMD Proposes An FPGA Subsystem Person-Area Interface For Linux

AMD engineers are proposing an FPGA Subsystem Person-Area Interface to beat present limitations of the Linux kernel’s FPGA supervisor subsystem.

AMD-Xilinx engineers are proposing a brand new sysfs interface for the FPGA subsystem that permits for extra user-space management over FPGAs. The prompt interface would deal with FPGA configuration, driver probe/take away, bridges, System Tree Overlay file assist for re-programming an FPGA whereas the working system is operating, and different capabilities for user-space not at the moment offered by the mainline kernel.

A “request for feedback” issued on the Linux kernel mailing record defined:

The present FPGA supervisor subsystem did not have any person area interface (apart from the standing/state in sysfs) in Kernel.

Mainly, FPGAs are semiconductor gadgets that may be reprogrammed for desired {hardware} performance. FPGAs could be reprogrammed at runtime with several types of logic and IPs as per person want and therefore there’s a want to make use of system tree overlays for eradicating/updating/including the gadgets at runtime for the IPs/controllers which are current in FPGA. However we have no person interface in kernel for updating the system tree at runtime.

Someday again there was a collection despatched by Pantelis Antoniou. This patch launched a person interface configfs for System Tree overlays, a way of dynamically altering the kernel’s stay System Tree. Nonetheless, this patch collection was not accepted in mainline as a result of numerous issues.

See Also

Inversion of Management Containers and the Dependency Injection sample

One of many main legitimate issues that had been raised with this configfs interface was safety because it opens up the interface to customers for modifying the stay system tree.

So, with a purpose to configure/program the FPGA gadgets, All the foremost distributors of FPGA are utilizing this configfs collection as out-of-tree patch for configuring the FPGAs and there was by no means an try to introduce a generic interface to configure/program the FPGA in upstream and therefore upstream kernel ended up in not having correct assist for FPGAs.

This proposal from AMD hopes to standardize the FPGA subsystem user-space interface in a fashion that’s appropriate for upstreaming into the mainline Linux kernel. We’ll see the place this work leads for enhancing FPGA assist on Linux.