memory-device: add and use memory_device_get_region_size()

We will factor out get_memory_region() from pc-dimm to memory device code
soon. Once that is done, get_region_size() can be implemented
generically and essentially be replaced by
memory_device_get_region_size (and work only on get_memory_region()).

We have some users of get_memory_region() (spapr and pc-dimm code) that are
only interested in the size. So let's rework them to use
memory_device_get_region_size() first, then we can factor out
get_memory_region() and eventually remove get_region_size() without
touching the same code multiple times.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-10-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 130f78d0de..3e43ec8742 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -161,16 +161,14 @@ static Property pc_dimm_properties[] = {
 static void pc_dimm_get_size(Object *obj, Visitor *v, const char *name,
                              void *opaque, Error **errp)
 {
+    Error *local_err = NULL;
     uint64_t value;
-    MemoryRegion *mr;
-    PCDIMMDevice *dimm = PC_DIMM(obj);
-    PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(obj);
 
-    mr = ddc->get_memory_region(dimm, errp);
-    if (!mr) {
+    value = memory_device_get_region_size(MEMORY_DEVICE(obj), &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
         return;
     }
-    value = memory_region_size(mr);
 
     visit_type_uint64(v, name, &value, errp);
 }