IB/uverbs: Return actual capacity from create SRQ operation

Pass actual capacity of created SRQ back to userspace, so that
userspace can report accurate capacities.  This requires an ABI bump,
to change struct ib_uverbs_create_srq_resp.

Signed-off-by: Dotan Barak <dotanb@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/uverbs_cmd.c

@@ -1864,6 +1864,8 @@ ssize_t ib_uverbs_create_srq(struct ib_uverbs_file *file,
 		goto err_destroy;
 
 	resp.srq_handle = uobj->uobject.id;
+	resp.max_wr     = attr.attr.max_wr;
+	resp.max_sge    = attr.attr.max_sge;
 
 	if (copy_to_user((void __user *) (unsigned long) cmd.response,
 			 &resp, sizeof resp)) {

include/rdma/ib_user_verbs.h

@@ -44,7 +44,7 @@
  * Increment this value if any changes that break userspace ABI
  * compatibility are made.
  */
-#define IB_USER_VERBS_ABI_VERSION	5
+#define IB_USER_VERBS_ABI_VERSION	6
 
 enum {
 	IB_USER_VERBS_CMD_GET_CONTEXT,
@@ -605,6 +605,9 @@ struct ib_uverbs_create_srq {
 
 struct ib_uverbs_create_srq_resp {
 	__u32 srq_handle;
+	__u32 max_wr;
+	__u32 max_sge;
+	__u32 reserved;
 };
 
 struct ib_uverbs_modify_srq {