drm/exec: Pass in initial # of objects

In cases where the # is known ahead of time, it is silly to do the table
resize dance.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Patchwork: https://patchwork.freedesktop.org/patch/568338/

drm/gpuvm: Let drm_gpuvm_bo_put() report when the vm_bo object is destroyed

Some users need to release resources attached to the vm_bo object when
it's destroyed. In Panthor's case, we need to release the pin ref so
BO pages can be returned to the system when all GPU mappings are gone.

This could be done through a custom drm_gpuvm::vm_bo_free() hook, but
this has all sort of locking implications that would force us to expose
a drm_gem_shmem_unpin_locked() helper, not to mention the fact that
having a ::vm_bo_free() implementation without a ::vm_bo_alloc() one
seems odd. So let's keep things simple, and extend drm_gpuvm_bo_put()
to report when the object is destroyed.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204151406.1977285-1-boris.brezillon@collabora.com

drm/gpuvm: fall back to drm_exec_lock_obj()

Fall back to drm_exec_lock_obj() if num_fences is zero for the
drm_gpuvm_prepare_* function family.

Otherwise dma_resv_reserve_fences() would actually allocate slots even
though num_fences is zero.

Cc: Christian König <christian.koenig@amd.com>
Acked-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231129220835.297885-2-dakr@redhat.com

drm/gpuvm: track/lock/validate external/evicted objects

Currently the DRM GPUVM offers common infrastructure to track GPU VA
allocations and mappings, generically connect GPU VA mappings to their
backing buffers and perform more complex mapping operations on the GPU VA
space.

However, there are more design patterns commonly used by drivers, which
can potentially be generalized in order to make the DRM GPUVM represent
a basis for GPU-VM implementations. In this context, this patch aims
at generalizing the following elements.

1) Provide a common dma-resv for GEM objects not being used outside of
this GPU-VM.

2) Provide tracking of external GEM objects (GEM objects which are
shared with other GPU-VMs).

3) Provide functions to efficiently lock all GEM objects dma-resv the
GPU-VM contains mappings of.

4) Provide tracking of evicted GEM objects the GPU-VM contains mappings
of, such that validation of evicted GEM objects is accelerated.

5) Provide some convinience functions for common patterns.

Big thanks to Boris Brezillon for his help to figure out locking for
drivers updating the GPU VA space within the fence signalling path.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-12-dakr@redhat.com

drm/gpuvm: add an abstraction for a VM / BO combination

Add an abstraction layer between the drm_gpuva mappings of a particular
drm_gem_object and this GEM object itself. The abstraction represents a
combination of a drm_gem_object and drm_gpuvm. The drm_gem_object holds
a list of drm_gpuvm_bo structures (the structure representing this
abstraction), while each drm_gpuvm_bo contains list of mappings of this
GEM object.

This has multiple advantages:

1) We can use the drm_gpuvm_bo structure to attach it to various lists
of the drm_gpuvm. This is useful for tracking external and evicted
objects per VM, which is introduced in subsequent patches.

2) Finding mappings of a certain drm_gem_object mapped in a certain
drm_gpuvm becomes much cheaper.

3) Drivers can derive and extend the structure to easily represent
driver specific states of a BO for a certain GPUVM.

The idea of this abstraction was taken from amdgpu, hence the credit for
this idea goes to the developers of amdgpu.

Cc: Christian König <christian.koenig@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-11-dakr@redhat.com

drm/gpuvm: reference count drm_gpuvm structures

Implement reference counting for struct drm_gpuvm.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-10-dakr@redhat.com

drm/gpuvm: add drm_gpuvm_flags to drm_gpuvm

Introduce flags for struct drm_gpuvm, this required by subsequent
commits.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-8-dakr@redhat.com

drm/gpuvm: add common dma-resv per struct drm_gpuvm

Provide a common dma-resv for GEM objects not being used outside of this
GPU-VM. This is used in a subsequent patch to generalize dma-resv,
external and evicted object handling and GEM validation.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-6-dakr@redhat.com

drm/gpuvm: export drm_gpuvm_range_valid()

Drivers may use this function to validate userspace requests in advance,
hence export it.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-4-dakr@redhat.com

drm/gpuvm: don't always WARN in drm_gpuvm_check_overflow()

Don't always WARN in drm_gpuvm_check_overflow() and separate it into a
drm_gpuvm_check_overflow() and a dedicated
drm_gpuvm_warn_check_overflow() variant.

This avoids printing warnings due to invalid userspace requests.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-3-dakr@redhat.com

drm/gpuvm: convert WARN() to drm_WARN() variants

Use drm_WARN() and drm_WARN_ON() variants to indicate drivers the
context the failing VM resides in.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-2-dakr@redhat.com

drm/gpuvm: Fix deprecated license identifier

"GPL-2.0-only" in the license header was incorrectly changed to the
now deprecated "GPL-2.0". Fix.

Cc: Maxime Ripard <mripard@kernel.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Reported-by: David Edelsohn <dje.gcc@gmail.com>
Closes: https://lore.kernel.org/dri-devel/5lfrhdpkwhpgzipgngojs3tyqfqbesifzu5nf4l5q3nhfdhcf2@25nmiq7tfrew/T/#m5c356d68815711eea30dd94cc6f7ea8cd4344fe3
Fixes: f7749a549b4f ("drm/gpuvm: Dual-licence the drm_gpuvm code GPL-2.0 OR MIT")
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231106114827.62492-1-thomas.hellstrom@linux.intel.com

drm/gpuvm: Dual-licence the drm_gpuvm code GPL-2.0 OR MIT

Dual-licence in order to make it possible for other non-GPL os'es
to re-implement the code. The use of EXPORT_SYMBOL_GPL() is intentionally
left untouched to prevent use of drm_gpuvm as a proxy for non-GPL drivers
to access GPL-only kernel symbols.

Much of the ideas and algorithms used in the drm_gpuvm code is already
present in one way or another in MIT-licensed code.

Cc: Danilo Krummrich <dakr@redhat.com>
Cc: airlied@gmail.com
Cc: daniel@ffwll.ch
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231010142725.8920-1-thomas.hellstrom@linux.intel.com

drm/gpuvm: allow building as module

Currently, the DRM GPUVM does not have any core dependencies preventing
a module build.

Also, new features from subsequent patches require helpers (namely
drm_exec) which can be built as module.

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920144343.64830-3-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