IB/mad: Convert allocations from kmem_cache to kzalloc

This patch implements allocating alternate receive MAD buffers within the MAD
stack.  Support for OPA to send/recv variable sized MADs is implemented later.

    1) Convert MAD allocations from kmem_cache to kzalloc

       kzalloc is more flexible to support devices with different sized MADs
       and research and testing showed that the current use of kmem_cache does
       not provide performance benefits over kzalloc.

    2) Change struct ib_mad_private to use a flex array for the mad data
    3) Allocate ib_mad_private based on the size specified by devices in
       rdma_max_mad_size.
    4) Carry the allocated size in ib_mad_private to be used when processing
       ib_mad_private objects.
    5) Alter DMA mappings based on the mad_size of ib_mad_private.
    6) Replace the use of sizeof and static defines as appropriate
    7) Add appropriate casts for the MAD data when calling processing
       functions.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/drivers/infiniband/core/mad_priv.h b/drivers/infiniband/core/mad_priv.h
index 7b19cba2adf0..44c0a7842a70 100644
--- a/drivers/infiniband/core/mad_priv.h
+++ b/drivers/infiniband/core/mad_priv.h
@@ -75,12 +75,9 @@ struct ib_mad_private_header {
 
 struct ib_mad_private {
 	struct ib_mad_private_header header;
+	size_t mad_size;
 	struct ib_grh grh;
-	union {
-		struct ib_mad mad;
-		struct ib_rmpp_mad rmpp_mad;
-		struct ib_smp smp;
-	} mad;
+	u8 mad[0];
 } __attribute__ ((packed));
 
 struct ib_rmpp_segment {