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: add common channel recovery

That sure was fun to untangle.

- handled per-runlist, rather than globally
- more straight-forward process in general
- various potential SW/HW races have been fixed
- fixes lockdep issues that were present in >=gk104's prior implementation
- volta recovery now actually stands a chance of working
- volta/turing waiting for PBDMA idle before engine reset
- turing using hw-provided TSG info for CTXSW_TIMEOUT

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

drm/nouveau/fifo: add chan/cgrp preempt()

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

drm/nouveau/fifo: add new engine context tracking

Channel groups have somewhat more complicated requirements than what we
currently support. An engine context is shared between all channels in
a channel group, VEID/subctx support (later) brings per-VEID components,
and we need to track an individual channel's engine context pointers.

This commit adds the structures and refcounting to support the above,
wrapping the prior implementation for the moment.

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

drm/nouveau/fifo: add cgrp, have all channels be part of one

Engine context tracking will move to nvkm_cgrp in later commits, so we
create SW-only channel groups on HW without support for them.

- switches to nvkm_chid for TSG/channel ID allocation

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

drm/nouveau/fifo: unify handling of channel classes

Adds the basic skeleton for common channel (group) interfaces.

- common behaviour between <gk104 and >=gk104 impl's
- separates priv/user channel objects
- passthrough to existing object for now, kludges removed later

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

drm/nouveau/fifo/gk110-: support writing channel group runlist entries

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>