net/mlx5e: XDP, Remove un-established assumptions on XDP buffer

Remove the assumption of non-zero linear length in the XDP xmit
function, used to serve both internal XDP_TX operations as well as
redirected-in requests.

Do not apply the MLX5E_XDP_MIN_INLINE check unless necessary.

Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index c266d073e2f2530cef2ca44a88f5997d944462db..d89f934570ee2611eac92ecb6745f753e3b61de0 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -477,18 +477,26 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
        u16 ds_cnt, inline_hdr_sz;
        u8 num_wqebbs = 1;
        int num_frags = 0;
+       bool inline_ok;
+       bool linear;
        u16 pi;
 
        struct mlx5e_xdpsq_stats *stats = sq->stats;
 
-       if (unlikely(dma_len < MLX5E_XDP_MIN_INLINE || sq->hw_mtu < dma_len)) {
+       inline_ok = sq->min_inline_mode == MLX5_INLINE_MODE_NONE ||
+               dma_len >= MLX5E_XDP_MIN_INLINE;
+
+       if (unlikely(!inline_ok || sq->hw_mtu < dma_len)) {
                stats->err++;
                return false;
        }
 
-       ds_cnt = MLX5E_TX_WQE_EMPTY_DS_COUNT + 1;
+       inline_hdr_sz = 0;
        if (sq->min_inline_mode != MLX5_INLINE_MODE_NONE)
-               ds_cnt++;
+               inline_hdr_sz = MLX5E_XDP_MIN_INLINE;
+
+       linear = !!(dma_len - inline_hdr_sz);
+       ds_cnt = MLX5E_TX_WQE_EMPTY_DS_COUNT + linear + !!inline_hdr_sz;
 
        /* check_result must be 0 if sinfo is passed. */
        if (!check_result) {
@@ -517,22 +525,23 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
        eseg = &wqe->eth;
        dseg = wqe->data;
 
-       inline_hdr_sz = 0;
-
        /* copy the inline part if required */
-       if (sq->min_inline_mode != MLX5_INLINE_MODE_NONE) {
+       if (inline_hdr_sz) {
                memcpy(eseg->inline_hdr.start, xdptxd->data, sizeof(eseg->inline_hdr.start));
                memcpy(dseg, xdptxd->data + sizeof(eseg->inline_hdr.start),
-                      MLX5E_XDP_MIN_INLINE - sizeof(eseg->inline_hdr.start));
-               dma_len  -= MLX5E_XDP_MIN_INLINE;
-               dma_addr += MLX5E_XDP_MIN_INLINE;
-               inline_hdr_sz = MLX5E_XDP_MIN_INLINE;
+                      inline_hdr_sz - sizeof(eseg->inline_hdr.start));
+               dma_len  -= inline_hdr_sz;
+               dma_addr += inline_hdr_sz;
                dseg++;
        }
 
        /* write the dma part */
-       dseg->addr       = cpu_to_be64(dma_addr);
-       dseg->byte_count = cpu_to_be32(dma_len);
+       if (linear) {
+               dseg->addr       = cpu_to_be64(dma_addr);
+               dseg->byte_count = cpu_to_be32(dma_len);
+               dseg->lkey       = sq->mkey_be;
+               dseg++;
+       }
 
        cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | MLX5_OPCODE_SEND);
 
@@ -543,7 +552,6 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
                memset(eseg, 0, sizeof(*eseg) - sizeof(eseg->trailer));
 
                eseg->inline_hdr.sz = cpu_to_be16(inline_hdr_sz);
-               dseg->lkey = sq->mkey_be;
 
                for (i = 0; i < num_frags; i++) {
                        skb_frag_t *frag = &xdptxdf->sinfo->frags[i];
@@ -553,10 +561,10 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
                                page_pool_get_dma_addr(skb_frag_page(frag)) +
                                skb_frag_off(frag);
 
-                       dseg++;
                        dseg->addr = cpu_to_be64(addr);
                        dseg->byte_count = cpu_to_be32(skb_frag_size(frag));
                        dseg->lkey = sq->mkey_be;
+                       dseg++;
                }
 
                cseg->qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_cnt);

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 6a278901b40b3ab17d1596627b52fb0489f6c07a..a95ce206391bfcd1c9ee31b4692efff6d220be53 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -1886,7 +1886,6 @@ int mlx5e_open_xdpsq(struct mlx5e_channel *c, struct mlx5e_params *params,
                        struct mlx5e_tx_wqe      *wqe  = mlx5_wq_cyc_get_wqe(&sq->wq, i);
                        struct mlx5_wqe_ctrl_seg *cseg = &wqe->ctrl;
                        struct mlx5_wqe_eth_seg  *eseg = &wqe->eth;
-                       struct mlx5_wqe_data_seg *dseg;
 
                        sq->db.wqe_info[i] = (struct mlx5e_xdp_wqe_info) {
                                .num_wqebbs = 1,
@@ -1895,9 +1894,6 @@ int mlx5e_open_xdpsq(struct mlx5e_channel *c, struct mlx5e_params *params,
 
                        cseg->qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_cnt);
                        eseg->inline_hdr.sz = cpu_to_be16(inline_hdr_sz);
-
-                       dseg = (struct mlx5_wqe_data_seg *)cseg + (ds_cnt - 1);
-                       dseg->lkey = sq->mkey_be;
                }
        }