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 d66b15ea82c4..2a32043d1abd 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 */