IB: Add caching of ports' LMC

Add an LMC cache to struct ib_device, and add a function
ib_get_cached_lmc() to query the cache.

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 14 insertions, 0 deletions

diff --git a/include/rdma/ib_cache.h b/include/rdma/ib_cache.h
index 5bf9834f7dca..f179d233ffc3 100644
--- a/include/rdma/ib_cache.h
+++ b/include/rdma/ib_cache.h
@@ -102,4 +102,17 @@ int ib_find_cached_pkey(struct ib_device    *device,
                         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.
+ * @lmc: The lmc value for the specified port for that device.
+ *
+ * ib_get_cached_lmc() fetches the specified lmc table entry stored in
+ * the local software cache.
+ */
+int ib_get_cached_lmc(struct ib_device *device,
+                      u8                port_num,
+                      u8                *lmc);
+
 #endif /* _IB_CACHE_H */
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 6bbf1b364400..aeb4fcd86a9e 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -827,6 +827,7 @@ struct ib_cache {
         struct ib_event_handler event_handler;
         struct ib_pkey_cache  **pkey_cache;
         struct ib_gid_cache   **gid_cache;
+        u8                     *lmc_cache;
 };
 
 struct ib_device {