SG2002 (Cvitek) TPU and Ion memory allocator driver layer.
This crate provides a hardware-only, OS-glue-free abstraction for the Cvitek SG2002 TPU together with the Ion buffer manager that the TPU relies on for DMA buffers. The high-level OS bindings (file descriptors, ioctl plumbing, mmap) live in the consuming kernel and call into the types exported here.