drm/amdgpu: add SRAT lookup for GPU-local memory

On A+A the GPU HBM is exposed as specific-purpose memory described by
SRAT, and the GPU reaches it at a system physical address over the
internal link, so the driver needs a way to discover that range.

Add amdgpu_acpi_find_gpu_memory_in_srat(), which resolves the GPU
proximity domain from the SRAT GENERIC_AFFINITY entry matching the PCI
device handle, then returns the enabled, non-hotpluggable memory range
of that domain.

No caller yet, the users follow.

v2:
- A+A VF/passthrough is identified later by missing FB BAR0
  (AMDGPU_VIRT_VRAM_IS_SPM), not by xgmi.connected_to_cpu.

v3:
- Rename best_base/best_len to mem_base/mem_len; first match, not a
  comparison.
- Drop the unused legacy packed-BDF PCI handle format.
- Log "no acpi generic initiator found" without extra PCI BDF.
- Use dev_err for error-return logs.

v4:
- Reverse Christmas-tree local declarations, one per line.
- Reject NULL base_addr/length with -EINVAL.

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>

0 files changed, 0 insertions, 0 deletions