drm/nouveau/fifo: add new channel classes

Exposes a bunch of the new features that became possible as a result
of the earlier commits. DRM will build on this in the future to add
support for features such as SCG ("async compute") and multi-device
rendering, as part of the work necessary to be able to write a half-
decent vulkan driver - finally.

For the moment, this just crudely ports DRM to the API changes.

- channel class interfaces now the same for all HW classes
- channel group class exposed (SCG)
- channel runqueue selector exposed (SCG)
- channel sub-device id control exposed (multi-device rendering)
- channel names in logging will reflect creating process, not fd owner
- explicit USERD allocation required by VOLTA_CHANNEL_GPFIFO_A and newer
- drm is smarter about determining the appropriate channel class to use

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fifo: add new engine context handling

Builds on the context tracking that was added earlier.

- marks engine context PTEs as 'priv' where possible

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fifo: add common runlist control

- less dependence on waiting for runlist updates, on GPUs that allow it
- supports runqueue selector in RAMRL entries
- completes switch to common runl/cgrp/chan topology info

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fifo: tidy up non-stall intr handling

- removes a layer of indirection in the intr handling
- prevents non-stall ctrl racing with unknown intrs

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fifo: use runlist engine info to lookup engine classes

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/fifo: add common runlist/engine topology

Creates an nvkm_runl for each runlist on the GPU, and an nvkm_engn for
each engine that is reachable from a runlist.

- basically what gk104- already does, but extended to all chips
- adds per-runlist CHID allocators (Ampere)
- splits g98/gt2xx out from g84 (different target engines)

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>