IB/core: Add ib_find_exact_cached_pkey()

When P_Key tables potentially contain both full and partial membership
copies for the same P_Key, we need a function to find the index for an
exact (16-bit) P_Key.

This is necessary when the master forwards QP1 MADs sent by guests.
If the guest has sent the MAD with a limited membership P_Key, we need
to to forward the MAD using the same limited membership P_Key.  Since
the master may have both the limited and the full member P_Keys in its
table, we must make sure to retrieve the limited membership P_Key in
this case.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/rdma/ib_cache.h b/include/rdma/ib_cache.h
index 00a2b8ec327f..ad9a3c280944 100644
--- a/include/rdma/ib_cache.h
+++ b/include/rdma/ib_cache.h
@@ -101,6 +101,22 @@ int ib_find_cached_pkey(struct ib_device    *device,
                         u16                 *index);
 
 /**
+ * ib_find_exact_cached_pkey - Returns the PKey table index where a specified
+ *   PKey value occurs. Comparison uses the FULL 16 bits (incl membership bit)
+ * @device: The device to query.
+ * @port_num: The port number of the device to search for the PKey.
+ * @pkey: The PKey value to search for.
+ * @index: The index into the cached PKey table where the PKey was found.
+ *
+ * ib_find_exact_cached_pkey() searches the specified PKey table in
+ * the local software cache.
+ */
+int ib_find_exact_cached_pkey(struct ib_device    *device,
+                              u8                   port_num,
+                              u16                  pkey,
+                              u16                 *index);
+
+/**
  * ib_get_cached_lmc - Returns a cached lmc table entry
  * @device: The device to query.
  * @port_num: The port number of the device to query.