RDMA/mlx5: Rewrite MAD processing logic to be readable

Multiple "if"s and "||" make extension of process_mad() function
as a tedious task, rewrite that function to be more readable.

Link: https://lore.kernel.org/r/20191029062745.7932-14-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/mlx5/mad.c b/drivers/infiniband/hw/mlx5/mad.c
index f49d9c7..1c87412 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mad.c
+++ b/drivers/infiniband/hw/mlx5/mad.c
@@ -74,58 +74,6 @@ static int mlx5_MAD_IFC(struct mlx5_ib_dev *dev, int ignore_mkey,
                                port);
 }
 
-static int process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
-                      const struct ib_wc *in_wc, const struct ib_grh *in_grh,
-                      const struct ib_mad *in_mad, struct ib_mad *out_mad)
-{
-       u16 slid;
-       int err;
-
-       slid = in_wc ? ib_lid_cpu16(in_wc->slid) : be16_to_cpu(IB_LID_PERMISSIVE);
-
-       if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP && slid == 0)
-               return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
-
-       if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
-           in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
-               if (in_mad->mad_hdr.method   != IB_MGMT_METHOD_GET &&
-                   in_mad->mad_hdr.method   != IB_MGMT_METHOD_SET &&
-                   in_mad->mad_hdr.method   != IB_MGMT_METHOD_TRAP_REPRESS)
-                       return IB_MAD_RESULT_SUCCESS;
-
-               /* Don't process SMInfo queries -- the SMA can't handle them.
-                */
-               if (in_mad->mad_hdr.attr_id == IB_SMP_ATTR_SM_INFO)
-                       return IB_MAD_RESULT_SUCCESS;
-       } else if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT ||
-                  in_mad->mad_hdr.mgmt_class == MLX5_IB_VENDOR_CLASS1   ||
-                  in_mad->mad_hdr.mgmt_class == MLX5_IB_VENDOR_CLASS2   ||
-                  in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_CONG_MGMT) {
-               if (in_mad->mad_hdr.method  != IB_MGMT_METHOD_GET &&
-                   in_mad->mad_hdr.method  != IB_MGMT_METHOD_SET)
-                       return IB_MAD_RESULT_SUCCESS;
-       } else {
-               return IB_MAD_RESULT_SUCCESS;
-       }
-
-       err = mlx5_MAD_IFC(to_mdev(ibdev),
-                          mad_flags & IB_MAD_IGNORE_MKEY,
-                          mad_flags & IB_MAD_IGNORE_BKEY,
-                          port_num, in_wc, in_grh, in_mad, out_mad);
-       if (err)
-               return IB_MAD_RESULT_FAILURE;
-
-       /* set return bit in status of directed route responses */
-       if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
-               out_mad->mad_hdr.status |= cpu_to_be16(1 << 15);
-
-       if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP_REPRESS)
-               /* no response for trap repress */
-               return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
-
-       return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
-}
-
 static void pma_cnt_ext_assign(struct ib_pma_portcounters_ext *pma_cnt_ext,
                               void *out)
 {
@@ -278,17 +226,63 @@ int mlx5_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
        struct mlx5_ib_dev *dev = to_mdev(ibdev);
        const struct ib_mad *in_mad = (const struct ib_mad *)in;
        struct ib_mad *out_mad = (struct ib_mad *)out;
-       int ret;
+       u8 mgmt_class = in_mad->mad_hdr.mgmt_class;
+       u8 method = in_mad->mad_hdr.method;
+       u16 slid;
+       int err;
 
-       if (MLX5_CAP_GEN(dev->mdev, vport_counters) &&
-           in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT &&
-           in_mad->mad_hdr.method == IB_MGMT_METHOD_GET) {
-               ret = process_pma_cmd(dev, port_num, in_mad, out_mad);
-       } else {
-               ret =  process_mad(ibdev, mad_flags, port_num, in_wc, in_grh,
-                                  in_mad, out_mad);
+       slid = in_wc ? ib_lid_cpu16(in_wc->slid) :
+                      be16_to_cpu(IB_LID_PERMISSIVE);
+
+       if (method == IB_MGMT_METHOD_TRAP && !slid)
+               return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
+
+       switch (mgmt_class) {
+       case IB_MGMT_CLASS_SUBN_LID_ROUTED:
+       case IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE: {
+               if (method != IB_MGMT_METHOD_GET &&
+                   method != IB_MGMT_METHOD_SET &&
+                   method != IB_MGMT_METHOD_TRAP_REPRESS)
+                       return IB_MAD_RESULT_SUCCESS;
+
+               /* Don't process SMInfo queries -- the SMA can't handle them.
+                */
+               if (in_mad->mad_hdr.attr_id == IB_SMP_ATTR_SM_INFO)
+                       return IB_MAD_RESULT_SUCCESS;
+       } break;
+       case IB_MGMT_CLASS_PERF_MGMT:
+               if (MLX5_CAP_GEN(dev->mdev, vport_counters) &&
+                   method == IB_MGMT_METHOD_GET)
+                       return process_pma_cmd(dev, port_num, in_mad, out_mad);
+               /* fallthrough */
+       case MLX5_IB_VENDOR_CLASS1:
+               /* fallthrough */
+       case MLX5_IB_VENDOR_CLASS2:
+       case IB_MGMT_CLASS_CONG_MGMT: {
+               if (method != IB_MGMT_METHOD_GET &&
+                   method != IB_MGMT_METHOD_SET)
+                       return IB_MAD_RESULT_SUCCESS;
+       } break;
+       default:
+               return IB_MAD_RESULT_SUCCESS;
        }
-       return ret;
+
+       err = mlx5_MAD_IFC(to_mdev(ibdev),
+                          mad_flags & IB_MAD_IGNORE_MKEY,
+                          mad_flags & IB_MAD_IGNORE_BKEY,
+                          port_num, in_wc, in_grh, in_mad, out_mad);
+       if (err)
+               return IB_MAD_RESULT_FAILURE;
+
+       /* set return bit in status of directed route responses */
+       if (mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
+               out_mad->mad_hdr.status |= cpu_to_be16(1 << 15);
+
+       if (method == IB_MGMT_METHOD_TRAP_REPRESS)
+               /* no response for trap repress */
+               return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
+
+       return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
 }
 
 int mlx5_query_ext_port_caps(struct mlx5_ib_dev *dev, u8 port)