[dpdk-dev] [PATCH] net/mlx5: fix calculating TSO inline size

[Yongseok Koh]

Tx descriptor for TSO embeds packet header to be replicated. If Tx inline
is enabled, there could be additional packet data inlined with 4B inline
header ahead. And between the header and additional inlined packet data,
there may be padding to make the inline part aligned to
MLX5_WQE_DWORD_SIZE. In calculating the total size of inlined data, the
size of inline header and padding is missing.

Fixes: 3f13f8c23a7c ("net/mlx5: support hardware TSO")
Cc: stable at dpdk.org

Signed-off-by: Shahaf Shuler <shahafs at mellanox.com>
Signed-off-by: Yongseok Koh <yskoh at mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 25 +++++++++----------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index fe9e7eac0..f89fa40b5 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -454,6 +454,7 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			length -= pkt_inline_sz;
 			addr += pkt_inline_sz;
 		}
+		raw += MLX5_WQE_DWORD_SIZE;
 		if (txq->tso_en) {
 			tso = buf->ol_flags & PKT_TX_TCP_SEG;
 			if (tso) {
@@ -486,7 +487,6 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 				copy_b = tso_header_sz - pkt_inline_sz;
 				/* First seg must contain all headers. */
 				assert(copy_b <= length);
-				raw += MLX5_WQE_DWORD_SIZE;
 				if (copy_b &&
 				   ((end - (uintptr_t)raw) > copy_b)) {
 					uint16_t n = (MLX5_WQE_DS(copy_b) -
@@ -499,14 +499,11 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 						   (void *)addr, copy_b);
 					addr += copy_b;
 					length -= copy_b;
+					/* Include padding for TSO header. */
+					copy_b = MLX5_WQE_DS(copy_b) *
+						 MLX5_WQE_DWORD_SIZE;
 					pkt_inline_sz += copy_b;
-					/*
-					 * Another DWORD will be added
-					 * in the inline part.
-					 */
-					raw += MLX5_WQE_DS(copy_b) *
-					       MLX5_WQE_DWORD_SIZE -
-					       MLX5_WQE_DWORD_SIZE;
+					raw += copy_b;
 				} else {
 					/* NOP WQE. */
 					wqe->ctrl = (rte_v128u32_t){
@@ -524,19 +521,20 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		}
 		/* Inline if enough room. */
 		if (inline_en || tso) {
+			uint32_t inl;
 			uintptr_t end = (uintptr_t)
 				(((uintptr_t)txq->wqes) +
 				 (1 << txq->wqe_n) * MLX5_WQE_SIZE);
 			unsigned int inline_room = max_inline *
 						   RTE_CACHE_LINE_SIZE -
-						   (pkt_inline_sz - 2);
+						   (pkt_inline_sz - 2) -
+						   !!tso * sizeof(inl);
 			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) :
 				0;
 
-			raw += MLX5_WQE_DWORD_SIZE;
 			if (copy_b && ((end - (uintptr_t)raw) > copy_b)) {
 				/*
 				 * One Dseg remains in the current WQE.  To
@@ -549,12 +547,7 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 					break;
 				max_wqe -= n;
 				if (tso) {
-					uint32_t inl =
-						htonl(copy_b | MLX5_INLINE_SEG);
-
-					pkt_inline_sz =
-						MLX5_WQE_DS(tso_header_sz) *
-						MLX5_WQE_DWORD_SIZE;
+					inl = htonl(copy_b | MLX5_INLINE_SEG);
 					rte_memcpy((void *)raw,
 						   (void *)&inl, sizeof(inl));
 					raw += sizeof(inl);
-- 
2.11.0