[IB] Fix MAD layer DMA mappings to avoid touching data buffer once mapped

The MAD layer was violating the DMA API by touching data buffers used
for sends after the DMA mapping was done.  This causes problems on
non-cache-coherent architectures, because the device doing DMA won't
see updates to the payload buffers that exist only in the CPU cache.

Fix this by having all MAD consumers use ib_create_send_mad() to
allocate their send buffers, and moving the DMA mapping into the MAD
layer so it can be done just before calling send (and after any
modifications of the send buffer by the MAD layer).

Tested on a non-cache-coherent PowerPC 440SPe system.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 0 insertions, 3 deletions

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index a5a963cb5676..f72d46d54e0a 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -595,11 +595,8 @@ struct ib_send_wr {
                 } atomic;
                 struct {
                         struct ib_ah *ah;
-                        struct ib_mad_hdr *mad_hdr;
                         u32     remote_qpn;
                         u32     remote_qkey;
-                        int     timeout_ms; /* valid for MADs only */
-                        int     retries;    /* valid for MADs only */
                         u16     pkey_index; /* valid for GSI only */
                         u8      port_num;   /* valid for DR SMPs on switch only */
                 } ud;