Questions about libdrm programming

[Zachary Catlin <z@zc.is>]

I'm interested in (1) using my graphics card for computations and
(2) low-level shader code, and I'm looking for guidance on how I would
go about doing the following operations with libdrm (sans Mesa):

* client-side initialization
* loading textures into the GPU
* loading a bytecode shader into the GPU
* creating a texture on the GPU without uploading data
* running the shader using the uploaded textures as inputs and the
  non-uploaded texture as the output
* transferring the output texture into main memory
* tear-down, finalization

The GPU in question is a Radeon RV730, if any hardware-dependent
discussion is needed. I've tried to understand the workflow by looking
at the Mesa and Plymouth sources and the documentation I've found for
the DRI/DRM, but I could still use some guidance.