drm/amdgpu: take the A+A VF GMC aperture from SRAT

Browse source

The A+A VF FB BAR is not usable, so resolve its aperture from SRAT in
GMC early_init. Skip later aperture assignment for SPM-backed devices,
and restrict the existing mmhub-based override to native A+A and APU.

The GPU reaches its HBM at a system physical address, so
vram_base_offset becomes aper_base as well, which makes PDB0 map GPU
address 0 onto that address.

The XGMI node segment size comes from the same place: once early_init
has resolved the aperture, use its size rather than the value derived
from the register, which does not describe the VF partition.

v2:
- Use (sriov_vf || passthrough) and amdgpu_virt_vram_is_spm()
  instead of connected_to_cpu for the SRAT aperture and node segment
  size.

v3:
- Resolve the SRAT aperture in GMC early_init and skip later aperture
  assignment in mc_init for SPM-backed devices.
- Rely on amdgpu_virt_vram_is_spm() without redundant VF/passthrough
  checks.

Signed-off-by: Zhigang Luo <zhigang.luo@amd.com>
Signed-off-by: Fangsheng Huang <Fangsheng.Huang@amd.com>
Signed-off-by: YuBiao Wang <YuBiao.Wang@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Zhigang Luo 2026-08-31 15:39:03 -04:00 • committed by Alex Deucher

parent 16c306d53d

commit 489ee1c344

2 changed files with 49 additions and 13 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

57

drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c

View file

5

drivers/gpu/drm/amd/amdgpu/mmhub_v4_2_0.c

View file