IB/srp: Add RDMA/CM support

Since the SRP_LOGIN_REQ defined in the SRP standard is larger than
what fits in the RDMA/CM login request private data, introduce a new
login request format for the RDMA/CM.

Note: since srp_daemon and ibsrpdm rely on the subnet manager and
since there is no equivalent of the IB subnet manager in non-IB
networks, login has to be performed manually for non-IB networks.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/srp/ib_srp.h

@@ -45,6 +45,7 @@
 #include <rdma/ib_sa.h>
 #include <rdma/ib_cm.h>
 #include <rdma/ib_fmr_pool.h>
+#include <rdma/rdma_cm.h>
 
 enum {
 	SRP_PATH_REC_TIMEOUT_MS	= 1000,
@@ -153,11 +154,18 @@ struct srp_rdma_ch {
 	struct completion	done;
 	int			status;
 
+	union {
+		struct ib_cm {
 			struct sa_path_rec	path;
 			struct ib_sa_query	*path_query;
 			int			path_query_id;
-
 			struct ib_cm_id		*cm_id;
+		} ib_cm;
+		struct rdma_cm {
+			struct rdma_cm_id	*cm_id;
+		} rdma_cm;
+	};
+
 	struct srp_iu	      **tx_ring;
 	struct srp_iu	      **rx_ring;
 	struct srp_request     *req_ring;
@@ -182,6 +190,7 @@ struct srp_target_port {
 	/* read only in the hot path */
 	u32			global_rkey;
 	struct srp_rdma_ch	*ch;
+	struct net		*net;
 	u32			ch_count;
 	u32			lkey;
 	enum srp_target_state	state;
@@ -194,7 +203,6 @@ struct srp_target_port {
 	union ib_gid		sgid;
 	__be64			id_ext;
 	__be64			ioc_guid;
-	__be64			service_id;
 	__be64			initiator_ext;
 	u16			io_class;
 	struct srp_host	       *srp_host;
@@ -210,8 +218,28 @@ struct srp_target_port {
 	int			comp_vector;
 	int			tl_retry_count;
 
+	bool			using_rdma_cm;
+
+	union {
+		struct {
+			__be64			service_id;
 			union ib_gid		orig_dgid;
 			__be16			pkey;
+		} ib_cm;
+		struct {
+			union {
+				struct sockaddr_in	ip4;
+				struct sockaddr_in6	ip6;
+				struct sockaddr_storage ss;
+			} src;
+			union {
+				struct sockaddr_in	ip4;
+				struct sockaddr_in6	ip6;
+				struct sockaddr_storage ss;
+			} dst;
+			bool src_specified;
+		} rdma_cm;
+	};
 
 	u32			rq_tmo_jiffies;
 

include/scsi/srp.h

@@ -129,6 +129,23 @@ struct srp_login_req {
 	u8	target_port_id[16];
 };
 
+/**
+ * struct srp_login_req_rdma - RDMA/CM login parameters.
+ *
+ * RDMA/CM over InfiniBand can only carry 92 - 36 = 56 bytes of private
+ * data. The %srp_login_req_rdma structure contains the same information as
+ * %srp_login_req but with the reserved data removed.
+ */
+struct srp_login_req_rdma {
+	u64	tag;
+	__be16	req_buf_fmt;
+	u8	req_flags;
+	u8	opcode;
+	__be32	req_it_iu_len;
+	u8	initiator_port_id[16];
+	u8	target_port_id[16];
+};
+
 /*
  * The SRP spec defines the size of the LOGIN_RSP structure to be 52
  * bytes, so it needs to be packed to avoid having it padded to 56