RDMA/ib_srp: Add more documentation

Make it more clear what the different ib_srp data structures represent.

Link: https://lore.kernel.org/r/20220215210511.28303-2-bvanassche@acm.orgSigned-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/ulp/srp/ib_srp.h

@@ -92,6 +92,9 @@ enum srp_iu_type {
 };
 
 /*
+ * RDMA adapter in the initiator system.
+ *
+ * @dev_list: List of RDMA ports associated with this RDMA adapter (srp_host).
  * @mr_page_mask: HCA memory registration page mask.
  * @mr_page_size: HCA memory registration page size.
  * @mr_max_size: Maximum size in bytes of a single FR registration request.
@@ -109,6 +112,12 @@ struct srp_device {
 	bool			use_fast_reg;
 };
 
+/*
+ * One port of an RDMA adapter in the initiator system.
+ *
+ * @target_list: List of connected target ports (struct srp_target_port).
+ * @target_lock: Protects @target_list.
+ */
 struct srp_host {
 	struct srp_device      *srp_dev;
 	u8			port;
@@ -183,7 +192,7 @@ struct srp_rdma_ch {
 };
 
 /**
- * struct srp_target_port
+ * struct srp_target_port - RDMA port in the SRP target system
  * @comp_vector: Completion vector used by the first RDMA channel created for
  *   this target port.
  */