drm/nouveau: implement 1:1 scheduler - entity relationship

Recent patches to the DRM scheduler [1][2] allow for a variable number
of run-queues and add support for (shared) workqueues rather than
dedicated kthreads per scheduler. This allows us to create a 1:1
relationship between a GPU scheduler and a scheduler entity, in order to
properly support firmware schedulers being able to handle an arbitrary
amount of dynamically allocated command ring buffers. This perfectly
matches Nouveau's needs, hence make use of it.

Topology wise we create one scheduler instance per client (handling
VM_BIND jobs) and one scheduler instance per channel (handling EXEC
jobs).

All channel scheduler instances share a workqueue, but every client
scheduler instance has a dedicated workqueue. The latter is required to
ensure that for VM_BIND job's free_job() work and run_job() work can
always run concurrently and hence, free_job() work can never stall
run_job() work. For EXEC jobs we don't have this requirement, since EXEC
job's free_job() does not require to take any locks which indirectly or
directly are held for allocations elsewhere.

[1] https://lore.kernel.org/all/8f53f7ef-7621-4f0b-bdef-d8d20bc497ff@redhat.com/T/
[2] https://lore.kernel.org/all/20231031032439.1558703-1-matthew.brost@intel.com/T/

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231114002728.3491-1-dakr@redhat.com

drm/nouveau: separately allocate struct nouveau_uvmm

Allocate struct nouveau_uvmm separately in preparation for subsequent
commits introducing reference counting for struct drm_gpuvm.

While at it, get rid of nouveau_uvmm_init() as indirection of
nouveau_uvmm_ioctl_vm_init() and perform some minor cleanups.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-9-dakr@redhat.com

drm/nouveau: make use of the GPUVM's shared dma-resv

DRM GEM objects private to a single GPUVM can use a shared dma-resv.
Make use of the shared dma-resv of GPUVM rather than a driver specific
one.

The shared dma-resv originates from a "root" GEM object serving as
container for the dma-resv to make it compatible with drm_exec.

In order to make sure the object proving the shared dma-resv can't be
freed up before the objects making use of it, let every such GEM object
take a reference on it.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-7-dakr@redhat.com

drm/nouveau: make use of drm_gpuvm_range_valid()

Use drm_gpuvm_range_valid() in order to validate userspace requests.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-5-dakr@redhat.com

drm/nouveau: uvmm: rename 'umgr' to 'base'

Rename struct drm_gpuvm within struct nouveau_uvmm from 'umgr' to base.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920144343.64830-4-dakr@redhat.com

drm/gpuvm: rename struct drm_gpuva_manager to struct drm_gpuvm

Rename struct drm_gpuva_manager to struct drm_gpuvm including
corresponding functions. This way the GPUVA manager's structures align
very well with the documentation of VM_BIND [1] and VM_BIND locking [2].

It also provides a better foundation for the naming of data structures
and functions introduced for implementing a common dma-resv per GPU-VM
including tracking of external and evicted objects in subsequent
patches.

[1] Documentation/gpu/drm-vm-bind-async.rst
[2] Documentation/gpu/drm-vm-bind-locking.rst

Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920144343.64830-2-dakr@redhat.com

drm/nouveau: uvmm: remove dedicated VM pointer from VMAs

VMAs can find their corresponding VM through their embedded struct
drm_gpuva which already carries a pointer to a struct drm_gpuva_manager
which the VM is based on. Hence, remove the struct nouveau_uvmm pointer
from struct nouveau_uvma to save a couple of bytes per mapping.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230807163238.2091-6-dakr@redhat.com

drm/nouveau: remove incorrect __user annotations

Fix copy-paste error causing EXEC and VM_BIND syscalls data pointers
to carry incorrect __user annotations.

Fixes: b88baab82871 ("drm/nouveau: implement new VM_BIND uAPI")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230807163238.2091-4-dakr@redhat.com

drm/nouveau: implement new VM_BIND uAPI

This commit provides the implementation for the new uapi motivated by the
Vulkan API. It allows user mode drivers (UMDs) to:

1) Initialize a GPU virtual address (VA) space via the new
DRM_IOCTL_NOUVEAU_VM_INIT ioctl for UMDs to specify the portion of VA
space managed by the kernel and userspace, respectively.

2) Allocate and free a VA space region as well as bind and unbind memory
to the GPUs VA space via the new DRM_IOCTL_NOUVEAU_VM_BIND ioctl.
UMDs can request the named operations to be processed either
synchronously or asynchronously. It supports DRM syncobjs
(incl. timelines) as synchronization mechanism. The management of the
GPU VA mappings is implemented with the DRM GPU VA manager.

3) Execute push buffers with the new DRM_IOCTL_NOUVEAU_EXEC ioctl. The
execution happens asynchronously. It supports DRM syncobj (incl.
timelines) as synchronization mechanism. DRM GEM object locking is
handled with drm_exec.

Both, DRM_IOCTL_NOUVEAU_VM_BIND and DRM_IOCTL_NOUVEAU_EXEC, use the DRM
GPU scheduler for the asynchronous paths.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804182406.5222-12-dakr@redhat.com