AMD CDX Bus Landing For Linux 6.4 To Interface Between APUs & FPGAs

Since last year AMD-Xilinx has been posting Linux patches for enabling CDX as a new bus between application processors (APUs) and FPGAs. The AMD CDX bus is now poised for introduction in the upcoming Linux 6.4 cycle.

With AMD CDX, FPGA devices can be dynamically discovered and controlled by the main application CPU/APU. AMD's been working on this Linux support for CDX as part of their future hardware support and now that code under review for months is finally ready for upstreaming to the mainline Linux kernel.

Based on the timing and all things considered, it would seem the AMD CDX bus is used with the forthcoming Ryzen 7040 series chips with the "XDNA AI" engine where there is a dedicated AI engine to be found in AMD's newest laptop chips based on FPGA IP from their Xilinx acquisition.

As of yesterday Greg Kroah-Hartman picked up the CDX patches via his char-misc-next branch, thus making it material ready for the Linux 6.4 merge window opening up in about one month. This initial AMD CDX Linux support includes the CDX bus driver, AMD Versal bindings, the CDX controller, and related CDX patches.

Thus AMD CDX support is added to the growing list of features coming with the Linux 6.4 stable release this summer.