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>
diff --git a/Documentation/infiniband/user_mad.txt b/Documentation/infiniband/user_mad.txt
index 8ec54b9..744687d 100644
--- a/Documentation/infiniband/user_mad.txt
+++ b/Documentation/infiniband/user_mad.txt
@@ -99,6 +99,20 @@
request/response pairs. The upper 32 bits are reserved for use by
the kernel and will be overwritten before a MAD is sent.
+P_Key Index Handling
+
+ The old ib_umad interface did not allow setting the P_Key index for
+ MADs that are sent and did not provide a way for obtaining the P_Key
+ index of received MADs. A new layout for struct ib_user_mad_hdr
+ with a pkey_index member has been defined; however, to preserve
+ binary compatibility with older applications, this new layout will
+ not be used unless the IB_USER_MAD_ENABLE_PKEY ioctl is called
+ before a file descriptor is used for anything else.
+
+ In September 2008, the IB_USER_MAD_ABI_VERSION will be incremented
+ to 6, the new layout of struct ib_user_mad_hdr will be used by
+ default, and the IB_USER_MAD_ENABLE_PKEY ioctl will be removed.
+
Setting IsSM Capability Bit
To set the IsSM capability bit for a port, simply open the