drm/amd: Add support for non-4K page size systems

This is v4 of the patch series enabling 64 KB system page size support.

v3 of this series [1] contained 6 patches, of which 4 have been picked up and applied to drm-next. The initial minimal infrastructure required for 64 KB page size support has already been merged upstream [2].

This series includes the remaining fixes:

- Patch 1 fixes a kernel crash observed when running rocminfo on systems with a 64 KB page size by updating the trap reservation size.

- Patch 2 updates AMDGPU_GTT_MAX_TRANSFER_SIZE to always match the PMD size across all page sizes.

Setup details:
==============
System details: Power10 LPAR using 64K pagesize.
AMD GPU:

Name:                    gfx90a
Marketing Name:          AMD Instinct MI210

Changes since v3:
-----------------
- Based on feedback from Felix and Christian, AMDGPU_VA_RESERVED_TRAP_SIZE has been updated. The virtual address space now reserves 64 KB for the trap, while only 8 KB is allocated for both 4 KB and 64 KB page sizes. This ensures that the allocation remains within the reserved region.

Links:
------
[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/

Previous versions:
------------------
RFC v3 resend:
https://lore.kernel.org/all/[email protected]/
RFC v3:
https://lore.kernel.org/all/[email protected]/
RFC v2:
https://lore.kernel.org/all/[email protected]/
RFC v1:
https://lore.kernel.org/all/[email protected]/

Donet Tom (2):
drm/amdgpu: Change AMDGPU_VA_RESERVED_TRAP_SIZE to 64KB drm/amdgpu: Fix AMDGPU_GTT_MAX_TRANSFER_SIZE for non-4K page size

 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 8 +++++---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h  | 2 +-
 drivers/gpu/drm/amd/amdgpu/vce_v1_0.c   | 3 ++-
 drivers/gpu/drm/amd/amdkfd/kfd_priv.h   | 4 ++--
 5 files changed, 11 insertions(+), 8 deletions(-)

2.52.0