drm/nouveau: nvkm/vmm: implement raw ops to manage uvmm

The new VM_BIND UAPI uses the DRM GPU VA manager to manage the VA space.
Hence, we a need a way to manipulate the MMUs page tables without going
through the internal range allocator implemented by nvkm/vmm.

This patch adds a raw interface for nvkm/vmm to pass the resposibility
for managing the address space and the corresponding map/unmap/sparse
operations to the upper layers.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804182406.5222-11-dakr@redhat.com

drm/nouveau/nvif: give every vmm object a human-readable identifier

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

drm/nouveau/mmu: support initialisation of client-managed address-spaces

NVKM is currently responsible for managing the allocation of a client's
GPU address-space, but there's various use-cases (ie. HMM address-space
mirroring) where giving a client more direct control is desirable.

This commit allows for a VMM to be created where the area allocated for
NVKM is limited to a client-specified window, the remainder of address-
space is controlled directly by the client.

Leaving a window is necessary to support various internal requirements,
but also to support existing allocation interfaces as not all of the HW
is capable of working with a HMM allocation.

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

drm/nouveau/mmu: define user interfaces to mmu vmm opertaions

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