IB/uverbs: Add device memory capabilities reporting

This change allows vendors to report device memory capability
max_dm_size - to user via uverbs command.

Signed-off-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/uverbs_cmd.c

@@ -4006,6 +4006,12 @@ int ib_uverbs_ex_query_device(struct ib_uverbs_file *file,
 	resp.cq_moderation_caps.max_cq_moderation_period =
 		attr.cq_caps.max_cq_moderation_period;
 	resp.response_length += sizeof(resp.cq_moderation_caps);
+
+	if (ucore->outlen < resp.response_length + sizeof(resp.max_dm_size))
+		goto end;
+
+	resp.max_dm_size = attr.max_dm_size;
+	resp.response_length += sizeof(resp.max_dm_size);
 end:
 	err = ib_copy_to_udata(ucore, &resp, resp.response_length);
 	return err;

include/rdma/ib_verbs.h

@@ -372,6 +372,7 @@ struct ib_device_attr {
 	u32			raw_packet_caps; /* Use ib_raw_packet_caps enum */
 	struct ib_tm_caps	tm_caps;
 	struct ib_cq_caps       cq_caps;
+	u64			max_dm_size;
 };
 
 enum ib_mtu {