path: root/Documentation/infiniband
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authorRoland Dreier <rolandd@cisco.com>2007-10-09 19:59:15 -0700
committerRoland Dreier <rolandd@cisco.com>2007-10-09 19:59:15 -0700
commit2be8e3ee8efd6f99ce454115c29d09750915021a (patch)
tree00e21e061a18c7bd1339ebbb637de9701863312d /Documentation/infiniband
parentc01759cee91379cc3cb551bfd7c76f1b51f91ca2 (diff)
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>
Diffstat (limited to 'Documentation/infiniband')
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/infiniband/user_mad.txt b/Documentation/infiniband/user_mad.txt
index 8ec54b974b6..744687dd195 100644
--- a/Documentation/infiniband/user_mad.txt
+++ b/Documentation/infiniband/user_mad.txt
@@ -99,6 +99,20 @@ Transaction IDs
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