VPU Memory Management Unit is based on ARM MMU-600.
It allows the creation of multiple virtual address spaces for
the device and map noncontinuous host memory (there is no dedicated
memory on the VPU).

Address space is implemented as a struct ivpu_mmu_context, it has an ID,
drm_mm allocator for VPU addresses and struct ivpu_mmu_pgtable that
holds actual 3-level, 4KB page table.
Context with ID 0 (global context) is created upon driver initialization
and it's mainly used for mapping memory required to execute
the firmware.
Contexts with non-zero IDs are user contexts allocated each time
the devices is open()-ed and they map command buffers and other
workload-related memory.
Workloads executing in a given contexts have access only
to the memory mapped in this context.

This patch is has two main files:
  - ivpu_mmu_context.c handles MMU page tables and memory mapping
  - ivpu_mmu.c implements a driver that programs the MMU device
Co-developed-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Co-developed-by: Krystian Pradzynski <krystian.pradzynski@linux.intel.com>
Signed-off-by: Krystian Pradzynski <krystian.pradzynski@linux.intel.com>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20230117092723.60441-3-jacek.lawrynowicz@linux.intel.com