IB/umad: Add P_Key index support

Add support for setting the P_Key index of sent MADs and getting the
P_Key index of received MADs.  This requires a change to the layout of
the ABI structure struct ib_user_mad_hdr, so to avoid breaking
compatibility, we default to the old (unchanged) ABI and add a new
ioctl IB_USER_MAD_ENABLE_PKEY that allows applications that are aware
of the new ABI to opt into using it.

We plan on switching to the new ABI by default in a year or so, and
this patch adds a warning that is printed when an application uses the
old ABI, to push people towards converting to the new ABI.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-by: Hal Rosenstock <hal@xsigo.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/include/rdma/ib_user_mad.h b/include/rdma/ib_user_mad.h
index d66b15ea82c..2a32043d1ab 100644
--- a/include/rdma/ib_user_mad.h
+++ b/include/rdma/ib_user_mad.h
@@ -52,7 +52,50 @@
  */
 
 /**
+ * ib_user_mad_hdr_old - Old version of MAD packet header without pkey_index
+ * @id - ID of agent MAD received with/to be sent with
+ * @status - 0 on successful receive, ETIMEDOUT if no response
+ *   received (transaction ID in data[] will be set to TID of original
+ *   request) (ignored on send)
+ * @timeout_ms - Milliseconds to wait for response (unset on receive)
+ * @retries - Number of automatic retries to attempt
+ * @qpn - Remote QP number received from/to be sent to
+ * @qkey - Remote Q_Key to be sent with (unset on receive)
+ * @lid - Remote lid received from/to be sent to
+ * @sl - Service level received with/to be sent with
+ * @path_bits - Local path bits received with/to be sent with
+ * @grh_present - If set, GRH was received/should be sent
+ * @gid_index - Local GID index to send with (unset on receive)
+ * @hop_limit - Hop limit in GRH
+ * @traffic_class - Traffic class in GRH
+ * @gid - Remote GID in GRH
+ * @flow_label - Flow label in GRH
+ */
+struct ib_user_mad_hdr_old {
+	__u32	id;
+	__u32	status;
+	__u32	timeout_ms;
+	__u32	retries;
+	__u32	length;
+	__be32	qpn;
+	__be32  qkey;
+	__be16	lid;
+	__u8	sl;
+	__u8	path_bits;
+	__u8	grh_present;
+	__u8	gid_index;
+	__u8	hop_limit;
+	__u8	traffic_class;
+	__u8	gid[16];
+	__be32	flow_label;
+};
+
+/**
  * ib_user_mad_hdr - MAD packet header
+ *   This layout allows specifying/receiving the P_Key index.  To use
+ *   this capability, an application must call the
+ *   IB_USER_MAD_ENABLE_PKEY ioctl on the user MAD file handle before
+ *   any other actions with the file handle.
  * @id - ID of agent MAD received with/to be sent with
  * @status - 0 on successful receive, ETIMEDOUT if no response
  *   received (transaction ID in data[] will be set to TID of original
@@ -70,6 +113,7 @@
  * @traffic_class - Traffic class in GRH
  * @gid - Remote GID in GRH
  * @flow_label - Flow label in GRH
+ * @pkey_index - P_Key index
  */
 struct ib_user_mad_hdr {
 	__u32	id;
@@ -88,6 +132,8 @@ struct ib_user_mad_hdr {
 	__u8	traffic_class;
 	__u8	gid[16];
 	__be32	flow_label;
+	__u16	pkey_index;
+	__u8	reserved[6];
 };
 
 /**
@@ -134,4 +180,6 @@ struct ib_user_mad_reg_req {
 
 #define IB_USER_MAD_UNREGISTER_AGENT	_IOW(IB_IOCTL_MAGIC, 2, __u32)
 
+#define IB_USER_MAD_ENABLE_PKEY		_IO(IB_IOCTL_MAGIC, 3)
+
 #endif /* IB_USER_MAD_H */