virtio_pmem: populate numa information

Compute the numa information for a virtio_pmem device from the memory
range of the device. Previously, the target_node was always 0 since
the ndr_desc.target_node field was never explicitly set. The code for
computing the numa node is taken from cxl_pmem_region_probe in
drivers/cxl/pmem.c.

Signed-off-by: Michael Sammler <[e-mail]>
Reviewed-by: Pasha Tatashin <[e-mail]>
Reviewed-by: Pankaj Gupta <[e-mail]>
Tested-by: Mina Almasry <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Michael S. Tsirkin <[e-mail]>

drivers/nvdimm/virtio_pmem.c

···
 static int virtio_pmem_probe(struct virtio_device *vdev)
 {
 	struct nd_region_desc ndr_desc = {};
-	int nid = dev_to_node(&vdev->dev);
 	struct nd_region *nd_region;
 	struct virtio_pmem *vpmem;
 	struct resource res;
···
 	dev_set_drvdata(&vdev->dev, vpmem->nvdimm_bus);
 
 	ndr_desc.res = &res;
-	ndr_desc.numa_node = nid;
+
+	ndr_desc.numa_node = memory_add_physaddr_to_nid(res.start);
+	ndr_desc.target_node = phys_to_target_node(res.start);
+	if (ndr_desc.target_node == NUMA_NO_NODE) {
+		ndr_desc.target_node = ndr_desc.numa_node;
+		dev_dbg(&vdev->dev, "changing target node from %d to %d",
+			NUMA_NO_NODE, ndr_desc.target_node);
+	}
+
 	ndr_desc.flush = async_pmem_flush;
 	ndr_desc.provider_data = vdev;
 	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);