drm/amdgpu: fetch the A+A VF VBIOS from the SRAT HBM range

On A+A the VF has no usable FB BAR, so the VBIOS copy cannot be read
through BAR 0. It lives in HBM, which the SRAT describes as
specific-purpose memory reachable at a system physical address.

Add a dedicated amdgpu_read_bios_from_spm() path that resolves the HBM
range from SRAT and maps it as write-back system memory. Keep the
existing SR-IOV dynamic critical region path when it is enabled,
matching the VRAM reader.

v2:
- Use a separate amdgpu_read_bios_from_spm() helper and leave
  amdgpu_read_bios_from_vram() unchanged.
- Keep the SR-IOV dynamic critical region path for SPM-backed VBIOS.
- Fetch VBIOS after the COMMON block and make it optional for
  SPM-backed SR-IOV VF and passthrough configurations.

v3:
- Keep the SRAT range local to the VBIOS path; GMC owns aper_base and
  aper_size.
- Map SPM with memremap(), memcpy(), and memunmap().
- 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>

0 files changed, 0 insertions, 0 deletions