drm/amdgpu: Flush TLB after mapping for VG20+XGMI

For VG20 + XGMI bridge, all mappings PTEs cache in TC, this may have
stall invalid PTEs in TC because one cache line has 8 pages. Need always
flush_tlb after updating mapping.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -837,6 +837,12 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 		goto error_unlock;
 	}
 
+	/* Vega20+XGMI where PTEs get inadvertently cached in L2 texture cache,
+	 * heavy-weight flush TLB unconditionally.
+	 */
+	flush_tlb |= adev->gmc.xgmi.num_physical_nodes &&
+		     adev->ip_versions[GC_HWIP][0] == IP_VERSION(9, 4, 0);
+
 	memset(&params, 0, sizeof(params));
 	params.adev = adev;
 	params.vm = vm;