drm/nouveau/fifo/r535: initial support

- Adds support for allocating CHANNEL_GPFIFO classes from RM.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230918202149.4343-39-skeggsb@gmail.com

drm/nouveau/fifo/tu102-: prepare for GSP-RM

- (temporarily) disable if GSP-RM detected, will be added later
- add dtor() so GSP-RM paths can cleanup properly
- add alternate engine context mapping interface for RM engines
- add alternate chid interfaces to handle RM USERD oddities

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230918202149.4343-26-skeggsb@gmail.com

drm/nouveau/fifo/ga100-: initial support

- replaces the hacked-up version that existed solely to support TTM

v2. remove earlier hack preventing use of non-stall intr for fences

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

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/vfn: move NV_USERMODE class from host

- uses proper class IDs for Turing/Ampere

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

drm/nouveau/fifo/ga102: initialise chid on return from channel creation

Turns out caller isn't zero-initialised after-all.

Fixes: 49b2dfc08182 ("drm/nouveau/ga102-: support ttm buffer moves via copy engine")
Reported-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210921090735.247236-1-skeggsb@gmail.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drm/nouveau/ga102-: support ttm buffer moves via copy engine

We don't currently have any kind of real acceleration on Ampere GPUs,
but the TTM memcpy() fallback paths aren't really designed to handle
copies between different devices, such as on Optimus systems, and
result in a kernel OOPS.

A few options were investigated to try and fix this, but didn't work
out, and likely would have resulted in a very unpleasant experience
for users anyway.

This commit adds just enough support for setting up a single channel
connected to a copy engine, which the kernel can use to accelerate
the buffer copies between devices. Userspace has no access to this
incomplete channel support, but it's suitable for TTM's needs.

A more complete implementation of host(fifo) for Ampere GPUs is in
the works, but the required changes are far too invasive that they
would be unsuitable to backport to fix this issue on current kernels.

v2: fix GPFIFO length in RAMFC (reported by Karol)

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: <stable@vger.kernel.org> # v5.12+
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Tested-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210916220406.666454-1-skeggsb@gmail.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>