IB/mlx4: Report TSO capabilities

Report to the user area the TSO device capabilities, it includes the
max_tso size and the QP types that support it.

The TSO is applicable only when when of the ports is ETH and the device
supports it.

uresp logic around rss_caps is updated to fix a till-now harmless bug
computing the length of the structure to copy. The code did not handle the
implicit padding before rss_caps correctly. This is necessay to copy
tss_caps successfully.

Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index f57229b..88b0aef 100644 (file)
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -429,6 +429,9 @@ int mlx4_ib_gid_index_to_real_index(struct mlx4_ib_dev *ibdev,
        return real_index;
 }
 
+#define field_avail(type, fld, sz) (offsetof(type, fld) + \
+                                   sizeof(((type *)0)->fld) <= (sz))
+
 static int mlx4_ib_query_device(struct ib_device *ibdev,
                                struct ib_device_attr *props,
                                struct ib_udata *uhw)
@@ -587,8 +590,7 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
                        sizeof(struct mlx4_wqe_data_seg);
        }
 
-       if (uhw->outlen >= resp.response_length + sizeof(resp.rss_caps)) {
-               resp.response_length += sizeof(resp.rss_caps);
+       if (field_avail(typeof(resp), rss_caps, uhw->outlen)) {
                if (props->rss_caps.supported_qpts) {
                        resp.rss_caps.rx_hash_function =
                                MLX4_IB_RX_HASH_FUNC_TOEPLITZ;
@@ -608,6 +610,22 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
                                resp.rss_caps.rx_hash_fields_mask |=
                                        MLX4_IB_RX_HASH_INNER;
                }
+               resp.response_length = offsetof(typeof(resp), rss_caps) +
+                                      sizeof(resp.rss_caps);
+       }
+
+       if (field_avail(typeof(resp), tso_caps, uhw->outlen)) {
+               if (dev->dev->caps.max_gso_sz &&
+                   ((mlx4_ib_port_link_layer(ibdev, 1) ==
+                   IB_LINK_LAYER_ETHERNET) ||
+                   (mlx4_ib_port_link_layer(ibdev, 2) ==
+                   IB_LINK_LAYER_ETHERNET))) {
+                       resp.tso_caps.max_tso = dev->dev->caps.max_gso_sz;
+                       resp.tso_caps.supported_qpts |=
+                               1 << IB_QPT_RAW_PACKET;
+               }
+               resp.response_length = offsetof(typeof(resp), tso_caps) +
+                                      sizeof(resp.tso_caps);
        }
 
        if (uhw->outlen) {

diff --git a/include/uapi/rdma/mlx4-abi.h b/include/uapi/rdma/mlx4-abi.h
index be58594..a448abd 100644 (file)
--- a/include/uapi/rdma/mlx4-abi.h
+++ b/include/uapi/rdma/mlx4-abi.h
@@ -170,12 +170,21 @@ enum query_device_resp_mask {
        MLX4_IB_QUERY_DEV_RESP_MASK_CORE_CLOCK_OFFSET = 1UL << 0,
 };
 
+struct mlx4_ib_tso_caps {
+       __u32 max_tso; /* Maximum tso payload size in bytes */
+       /* Corresponding bit will be set if qp type from
+        * 'enum ib_qp_type' is supported.
+        */
+       __u32 supported_qpts;
+};
+
 struct mlx4_uverbs_ex_query_device_resp {
        __u32                   comp_mask;
        __u32                   response_length;
        __u64                   hca_core_clock_offset;
        __u32                   max_inl_recv_sz;
        struct mlx4_ib_rss_caps rss_caps;
+       struct mlx4_ib_tso_caps tso_caps;
 };
 
 #endif /* MLX4_ABI_USER_H */