net/mlx5: change calculating inline room for Tx

Current implementation is error-prone if the max inline size
(txq->max_inilne) is decoupled from txq->inline_en and becomes zero. If it
becomes zero, HW can crash due to WQ overflow.

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
Acked-by: Shahaf Shuler <shahafs@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 2e208bf..6254228 100644 (file)
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -499,6 +499,8 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
        unsigned int j = 0;
        unsigned int k = 0;
        unsigned int max;
+       unsigned int max_inline = txq->max_inline;
+       const unsigned int inline_en = !!max_inline && txq->inline_en;
        uint16_t max_wqe;
        unsigned int comp;
        volatile struct mlx5_wqe_v *wqe = NULL;
@@ -685,14 +687,14 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
                        }
                }
                /* Inline if enough room. */
-               if (txq->inline_en || tso) {
+               if (inline_en || tso) {
                        uintptr_t end = (uintptr_t)
                                (((uintptr_t)txq->wqes) +
                                 (1 << txq->wqe_n) * MLX5_WQE_SIZE);
-                       unsigned int max_inline = txq->max_inline *
-                                                 RTE_CACHE_LINE_SIZE -
-                                                 (pkt_inline_sz - 2);
-                       uintptr_t addr_end = (addr + max_inline) &
+                       unsigned int inline_room = max_inline *
+                                                  RTE_CACHE_LINE_SIZE -
+                                                  (pkt_inline_sz - 2);
+                       uintptr_t addr_end = (addr + inline_room) &
                                             ~(RTE_CACHE_LINE_SIZE - 1);
                        unsigned int copy_b = (addr_end > addr) ?
                                RTE_MIN((addr_end - addr), length) :