drm/amdgpu/gmc9: set vram_width properly for SR-IOV

For SR-IOV, vram_width can't be read from ATOM as
RAVEN, and DF related registers is not readable, so hardcord
is the only way to set the correct vram_width.
Reviewed-by: Yintian Tao <yttao@amd.com>
Signed-off-by: Trigger Huang <Trigger.Huang@amd.com>
Signed-off-by: Yintian Tao <yttao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -813,8 +813,16 @@ static int gmc_v9_0_mc_init(struct amdgpu_device *adev)
 	int chansize, numchan;
 	int r;
 
-	if (amdgpu_emu_mode != 1)
+	if (amdgpu_sriov_vf(adev)) {
+		/* For Vega10 SR-IOV, vram_width can't be read from ATOM as RAVEN,
+		 * and DF related registers is not readable, seems hardcord is the
+		 * only way to set the correct vram_width
+		 */
+		adev->gmc.vram_width = 2048;
+	} else if (amdgpu_emu_mode != 1) {
 		adev->gmc.vram_width = amdgpu_atomfirmware_get_vram_width(adev);
+	}
+
 	if (!adev->gmc.vram_width) {
 		/* hbm memory channel size */
 		if (adev->flags & AMD_IS_APU)