IB/mlx4: Add IPoIB checksum offload support

ConnectX devices support checksum generation and verification of TCP
and UDP packets for UD IPoIB messages.  This patch checks if the HCA
supports this and sets the IB_DEVICE_UD_IP_CSUM capability flag if it
does.  It implements support for handling the IB_SEND_IP_CSUM send
flag and setting the csum_ok field in receive work completions.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Ali Ayub <ali@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mlx4/cq.c b/drivers/infiniband/hw/mlx4/cq.c
index 7360bbafbe84..d2e32b03e2f7 100644
--- a/drivers/infiniband/hw/mlx4/cq.c
+++ b/drivers/infiniband/hw/mlx4/cq.c
@@ -297,6 +297,20 @@ static void mlx4_ib_handle_error_cqe(struct mlx4_err_cqe *cqe,
         wc->vendor_err = cqe->vendor_err_syndrome;
 }
 
+static int mlx4_ib_ipoib_csum_ok(__be32 status, __be16 checksum)
+{
+        return ((status & cpu_to_be32(MLX4_CQE_IPOIB_STATUS_IPV4        |
+                                      MLX4_CQE_IPOIB_STATUS_IPV4F       |
+                                      MLX4_CQE_IPOIB_STATUS_IPV4OPT     |
+                                      MLX4_CQE_IPOIB_STATUS_IPV6        |
+                                      MLX4_CQE_IPOIB_STATUS_IPOK)) ==
+                cpu_to_be32(MLX4_CQE_IPOIB_STATUS_IPV4  |
+                            MLX4_CQE_IPOIB_STATUS_IPOK))                &&
+                (status & cpu_to_be32(MLX4_CQE_IPOIB_STATUS_UDP |
+                                      MLX4_CQE_IPOIB_STATUS_TCP))       &&
+                checksum == cpu_to_be16(0xffff);
+}
+
 static int mlx4_ib_poll_one(struct mlx4_ib_cq *cq,
                             struct mlx4_ib_qp **cur_qp,
                             struct ib_wc *wc)
@@ -434,6 +448,8 @@ static int mlx4_ib_poll_one(struct mlx4_ib_cq *cq,
                 wc->dlid_path_bits = (g_mlpath_rqpn >> 24) & 0x7f;
                 wc->wc_flags      |= g_mlpath_rqpn & 0x80000000 ? IB_WC_GRH : 0;
                 wc->pkey_index     = be32_to_cpu(cqe->immed_rss_invalid) & 0x7f;
+                wc->csum_ok        = mlx4_ib_ipoib_csum_ok(cqe->ipoib_status,
+                                                           cqe->checksum);
         }
 
         return 0;