RDMA/core: Track device memory MRs

Device memory (DM) are registered as MR during initialization flow, these
MRs were not tracked by resource tracker and had res->valid set as a
false. Update the code to manage them too.

Before this change:
$ ibv_rc_pingpong -j &
$ rdma res show mr <-- shows nothing

After this change:
$ ibv_rc_pingpong -j &
$ rdma res show mr
dev ibp0s9 mrn 0 mrlen 4096 pdn 3 pid 734 comm ibv_rc_pingpong

Fixes: be934cca ("IB/uverbs: Add device memory registration ioctl support")
Link: https://lore.kernel.org/r/20201117070148.1974114-2-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/uverbs_std_types_mr.c

@@ -33,6 +33,7 @@
 #include "rdma_core.h"
 #include "uverbs.h"
 #include <rdma/uverbs_std_types.h>
+#include "restrack.h"
 
 static int uverbs_free_mr(struct ib_uobject *uobject,
 			  enum rdma_remove_reason why,
@@ -134,6 +135,9 @@ static int UVERBS_HANDLER(UVERBS_METHOD_DM_MR_REG)(
 	atomic_inc(&pd->usecnt);
 	atomic_inc(&dm->usecnt);
 
+	rdma_restrack_new(&mr->res, RDMA_RESTRACK_MR);
+	rdma_restrack_set_name(&mr->res, NULL);
+	rdma_restrack_add(&mr->res);
 	uobj->object = mr;
 
 	uverbs_finalize_uobj_create(attrs, UVERBS_ATTR_REG_DM_MR_HANDLE);