Add link_layer field port attribute

The new field has three possible values: IBV_LINK_LAYER_UNSPECIFIED,
IBV_LINK_LAYER_INFINIBAND, IBV_LINK_LAYER_ETHERNET.  It can be used by
applications to know the link layer used by the port, which can be
either InfiniBand or Ethernet.

The addition of the new field does not change the size of struct
ibv_port_attr due to alignment of the preceding fields.  Binary
compatibility between the library to applications is kept, since old
apps running over new library do not read this field, and new apps
running over old library will determine the link layer as unspecified
and hence take their IB code path.

The solution was suggested by Roland Dreier <roland@purestorage.com>
and Jason Gunthorpe <jgunthorpe@obsidianresearch.com>

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.co.il>
Signed-off-by: Eli Cohen <eli@mellanox.co.il>

diff --git a/include/infiniband/verbs.h b/include/infiniband/verbs.h
index 0f1cb2eedc231069fe14cc6df8faaea6474b1f3f..058d6faac7c594adb7b351a8aabe03a7ed4357e2 100644 (file)
--- a/include/infiniband/verbs.h
+++ b/include/infiniband/verbs.h
@@ -161,6 +161,12 @@ enum ibv_port_state {
        IBV_PORT_ACTIVE_DEFER   = 5
 };
 
+enum {
+       IBV_LINK_LAYER_UNSPECIFIED,
+       IBV_LINK_LAYER_INFINIBAND,
+       IBV_LINK_LAYER_ETHERNET,
+};
+
 struct ibv_port_attr {
        enum ibv_port_state     state;
        enum ibv_mtu            max_mtu;
@@ -181,6 +187,8 @@ struct ibv_port_attr {
        uint8_t                 active_width;
        uint8_t                 active_speed;
        uint8_t                 phys_state;
+       uint8_t                 link_layer;
+       uint8_t                 reserved;
 };
 
 enum ibv_event_type {
@@ -767,6 +775,20 @@ int ibv_query_device(struct ibv_context *context,
 int ibv_query_port(struct ibv_context *context, uint8_t port_num,
                   struct ibv_port_attr *port_attr);
 
+static inline int ___ibv_query_port(struct ibv_context *context,
+                                   uint8_t port_num,
+                                   struct ibv_port_attr *port_attr)
+{
+       /* For compatability when running with old libibverbs */
+       port_attr->link_layer = IBV_LINK_LAYER_UNSPECIFIED;
+       port_attr->reserved   = 0;
+
+       return ibv_query_port(context, port_num, port_attr);
+}
+
+#define ibv_query_port(context, port_num, port_attr) \
+       ___ibv_query_port(context, port_num, port_attr)
+
 /**
  * ibv_query_gid - Get a GID table entry
  */
@@ -1097,4 +1119,5 @@ END_C_DECLS
 
 #  undef __attribute_const
 
+
 #endif /* INFINIBAND_VERBS_H */

diff --git a/man/ibv_query_port.3 b/man/ibv_query_port.3
index 882470db138cc79ab3cccc1f16853e20746d5fcb..9bedd90e111d5ac9b7bb8e15b251fe26c0730676 100644 (file)
--- a/man/ibv_query_port.3
+++ b/man/ibv_query_port.3
@@ -44,9 +44,13 @@ uint8_t                 init_type_reply;/* Type of initialization performed by S
 uint8_t                 active_width;   /* Currently active link width */
 uint8_t                 active_speed;   /* Currently active link speed */
 uint8_t                 phys_state;     /* Physical port state */
+uint8_t                 link_layer;     /* link layer protocol of the port */
 .in -8
 };
 .sp
+possible values for the link layer field are IBV_LINK_LAYER_INFINIBAND,
+IBV_LINK_LAYER_ETHERNET, or IBV_LINK_LAYER_UNSPECIFIED.
+.sp
 .fi
 .SH "RETURN VALUE"
 .B ibv_query_port()