From e7f2effc9220dc5d71b0bb550bcc903badc7bac4 Mon Sep 17 00:00:00 2001 From: Ruifeng Wang Date: Wed, 13 Apr 2022 18:31:56 +0800 Subject: [PATCH] net/bnxt: fix reordering in NEON Rx Rx descriptor contains a valid bit which indicates readiness of the rest of descriptor words. Hence, the word contains valid bit must be read prior to other words. In NEON vector path, two contiguous 8B descriptor are loaded to a single NEON register. Given vector load ensures no 16B atomicity, read of the word that includes valid bit could be reordered after read of other words. In this case, data could be invalid. Reloaded lower 64b after read barrier. This ensures what fetched is correct. Also fixed comments that not pertains to Arm platform architecture. Fixes: deae85145c64 ("net/bnxt: handle multiple packets per loop in vector Rx") Cc: stable@dpdk.org Signed-off-by: Ruifeng Wang Reviewed-by: Ajit Khaparde --- drivers/net/bnxt/bnxt_rxtx_vec_neon.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/net/bnxt/bnxt_rxtx_vec_neon.c b/drivers/net/bnxt/bnxt_rxtx_vec_neon.c index 779e23ac4f..32f8e59b3a 100644 --- a/drivers/net/bnxt/bnxt_rxtx_vec_neon.c +++ b/drivers/net/bnxt/bnxt_rxtx_vec_neon.c @@ -231,25 +231,38 @@ recv_burst_vec_neon(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts) } /* - * Load the four current descriptors into SSE registers in - * reverse order to ensure consistent state. + * Load the four current descriptors into NEON registers. + * IO barriers are used to ensure consistent state. */ rxcmp1[3] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 7]); rte_io_rmb(); + /* Reload lower 64b of descriptors to make it ordered after info3_v. */ + rxcmp1[3] = vreinterpretq_u32_u64(vld1q_lane_u64 + ((void *)&cpr->cp_desc_ring[cons + 7], + vreinterpretq_u64_u32(rxcmp1[3]), 0)); rxcmp[3] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 6]); rxcmp1[2] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 5]); rte_io_rmb(); + rxcmp1[2] = vreinterpretq_u32_u64(vld1q_lane_u64 + ((void *)&cpr->cp_desc_ring[cons + 5], + vreinterpretq_u64_u32(rxcmp1[2]), 0)); rxcmp[2] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 4]); t1 = vreinterpretq_u64_u32(vzip2q_u32(rxcmp1[2], rxcmp1[3])); rxcmp1[1] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 3]); rte_io_rmb(); + rxcmp1[1] = vreinterpretq_u32_u64(vld1q_lane_u64 + ((void *)&cpr->cp_desc_ring[cons + 3], + vreinterpretq_u64_u32(rxcmp1[1]), 0)); rxcmp[1] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 2]); rxcmp1[0] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 1]); rte_io_rmb(); + rxcmp1[0] = vreinterpretq_u32_u64(vld1q_lane_u64 + ((void *)&cpr->cp_desc_ring[cons + 1], + vreinterpretq_u64_u32(rxcmp1[0]), 0)); rxcmp[0] = vld1q_u32((void *)&cpr->cp_desc_ring[cons + 0]); t0 = vreinterpretq_u64_u32(vzip2q_u32(rxcmp1[0], rxcmp1[1])); -- 2.39.5