[dpdk-dev] [PATCH] net/mlx5: fix build with strict alignment enabled

[Ali Alnubani]

This patch converts some of the casts to unaligned integer types.

This fixes the following error, which is seen on x86, with
gcc 7.4.0:

drivers/net/mlx5/mlx5_rxtx.c: In function ‘mlx5_tx_dseg_iptr’:
drivers/net/mlx5/mlx5_rxtx.c:2740:9: error: passing argument 1 of
‘memcpy’ makes pointer from integer without a cast
[-Werror=int-conversion]
  memcpy(dst, src, len);
         ^~~

The memcpy call is replaced with 2 copies of uint32 for better
performance on ARM.

Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")

Reported-by: Jeremy Plsek <jplsek at iol.unh.edu>
Signed-off-by: Ali Alnubani <alialnu at mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 10d0ca116..d6a5106c5 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -2747,27 +2747,33 @@ mlx5_tx_dseg_iptr(struct mlx5_txq_data *restrict txq,
 	/* Unrolled implementation of generic rte_memcpy. */
 	dst = (uintptr_t)&dseg->inline_data[0];
 	src = (uintptr_t)buf;
+	if (len & 0x08) {
 #ifdef RTE_ARCH_STRICT_ALIGN
-	memcpy(dst, src, len);
+		assert(dst == RTE_PTR_ALIGN(dst, sizeof(uint32_t)));
+		*(uint32_t *)dst = *(unaligned_uint32_t *)src;
+		dst += sizeof(uint32_t);
+		src += sizeof(uint32_t);
+		*(uint32_t *)dst = *(unaligned_uint32_t *)src;
+		dst += sizeof(uint32_t);
+		src += sizeof(uint32_t);
 #else
-	if (len & 0x08) {
-		*(uint64_t *)dst = *(uint64_t *)src;
+		*(uint64_t *)dst = *(unaligned_uint64_t *)src;
 		dst += sizeof(uint64_t);
 		src += sizeof(uint64_t);
+#endif
 	}
 	if (len & 0x04) {
-		*(uint32_t *)dst = *(uint32_t *)src;
+		*(uint32_t *)dst = *(unaligned_uint32_t *)src;
 		dst += sizeof(uint32_t);
 		src += sizeof(uint32_t);
 	}
 	if (len & 0x02) {
-		*(uint16_t *)dst = *(uint16_t *)src;
+		*(uint16_t *)dst = *(unaligned_uint16_t *)src;
 		dst += sizeof(uint16_t);
 		src += sizeof(uint16_t);
 	}
 	if (len & 0x01)
 		*(uint8_t *)dst = *(uint8_t *)src;
-#endif
 }
 
 /**
-- 
2.23.0