net/thunderx: reduce writes to mbuf

With the mbuf rework, we now have 8 contiguous bytes to be
rearmed in the mbuf at 8B naturally aligned address.
Use single 8B write to avoid multiple 2B writes in Rx path.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Signed-off-by: Maciej Czekaj <maciej.czekaj@caviumnetworks.com>

diff --git a/drivers/net/thunderx/nicvf_ethdev.c b/drivers/net/thunderx/nicvf_ethdev.c
index 36ff94f..e4910c9 100644 (file)
--- a/drivers/net/thunderx/nicvf_ethdev.c
+++ b/drivers/net/thunderx/nicvf_ethdev.c
@@ -1232,6 +1232,23 @@ nicvf_dev_tx_queue_stop(struct rte_eth_dev *dev, uint16_t qidx)
        return nicvf_vf_stop_tx_queue(dev, nic, qidx);
 }
 
+static inline void
+nicvf_rxq_mbuf_setup(struct nicvf_rxq *rxq)
+{
+       uintptr_t p;
+       struct rte_mbuf mb_def;
+
+       RTE_BUILD_BUG_ON(sizeof(union mbuf_initializer) != 8);
+       mb_def.nb_segs = 1;
+       mb_def.data_off = RTE_PKTMBUF_HEADROOM;
+       mb_def.port = rxq->port_id;
+       rte_mbuf_refcnt_set(&mb_def, 1);
+
+       /* Prevent compiler reordering: rearm_data covers previous fields */
+       rte_compiler_barrier();
+       p = (uintptr_t)&mb_def.rearm_data;
+       rxq->mbuf_initializer.value = *(uint64_t *)p;
+}
 
 static int
 nicvf_dev_rx_queue_setup(struct rte_eth_dev *dev, uint16_t qidx,
@@ -1324,6 +1341,7 @@ nicvf_dev_rx_queue_setup(struct rte_eth_dev *dev, uint16_t qidx,
        else
                rxq->rbptr_offset = NICVF_CQE_RBPTR_WORD;
 
+       nicvf_rxq_mbuf_setup(rxq);
 
        /* Alloc completion queue */
        if (nicvf_qset_cq_alloc(dev, nic, rxq, rxq->queue_id, nb_desc)) {

diff --git a/drivers/net/thunderx/nicvf_rxtx.c b/drivers/net/thunderx/nicvf_rxtx.c
index fc43b74..003ab06 100644 (file)
--- a/drivers/net/thunderx/nicvf_rxtx.c
+++ b/drivers/net/thunderx/nicvf_rxtx.c
@@ -430,9 +430,9 @@ nicvf_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
        union cq_entry_t *desc = rxq->desc;
        const uint64_t cqe_mask = rxq->qlen_mask;
        uint64_t rb0_ptr, mbuf_phys_off = rxq->mbuf_phys_off;
+       const uint64_t mbuf_init = rxq->mbuf_initializer.value;
        uint32_t cqe_head = rxq->head & cqe_mask;
        int32_t available_space = rxq->available_space;
-       uint8_t port_id = rxq->port_id;
        const uint8_t rbptr_offset = rxq->rbptr_offset;
 
        to_process = nicvf_rx_pkts_to_process(rxq, nb_pkts, available_space);
@@ -448,17 +448,12 @@ nicvf_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
                rb0_ptr = *((uint64_t *)cqe_rx + rbptr_offset);
                pkt = (struct rte_mbuf *)nicvf_mbuff_phy2virt
                                (rb0_ptr - cqe_rx_w1.align_pad, mbuf_phys_off);
-
                pkt->ol_flags = 0;
-               pkt->port = port_id;
                pkt->data_len = cqe_rx_w3.rb0_sz;
-               pkt->data_off = RTE_PKTMBUF_HEADROOM + cqe_rx_w1.align_pad;
-               pkt->nb_segs = 1;
                pkt->pkt_len = cqe_rx_w3.rb0_sz;
                pkt->packet_type = nicvf_rx_classify_pkt(cqe_rx_w0);
-
+               nicvf_mbuff_init_update(pkt, mbuf_init, cqe_rx_w1.align_pad);
                nicvf_rx_offload(cqe_rx_w0, cqe_rx_w2, pkt);
-               rte_mbuf_refcnt_set(pkt, 1);
                rx_pkts[i] = pkt;
                cqe_head = (cqe_head + 1) & cqe_mask;
                nicvf_prefetch_store_keep(pkt);
@@ -481,8 +476,9 @@ nicvf_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 
 static inline uint16_t __hot
 nicvf_process_cq_mseg_entry(struct cqe_rx_t *cqe_rx,
-                       uint64_t mbuf_phys_off, uint8_t port_id,
-                       struct rte_mbuf **rx_pkt, uint8_t rbptr_offset)
+                       uint64_t mbuf_phys_off,
+                       struct rte_mbuf **rx_pkt, uint8_t rbptr_offset,
+                       uint64_t mbuf_init)
 {
        struct rte_mbuf *pkt, *seg, *prev;
        cqe_rx_word0_t cqe_rx_w0;
@@ -501,12 +497,10 @@ nicvf_process_cq_mseg_entry(struct cqe_rx_t *cqe_rx,
                        (rb_ptr[0] - cqe_rx_w1.align_pad, mbuf_phys_off);
 
        pkt->ol_flags = 0;
-       pkt->port = port_id;
-       pkt->data_off = RTE_PKTMBUF_HEADROOM + cqe_rx_w1.align_pad;
-       pkt->nb_segs = nb_segs;
        pkt->pkt_len = cqe_rx_w1.pkt_len;
        pkt->data_len = rb_sz[nicvf_frag_num(0)];
-       rte_mbuf_refcnt_set(pkt, 1);
+       nicvf_mbuff_init_mseg_update(
+                               pkt, mbuf_init, cqe_rx_w1.align_pad, nb_segs);
        pkt->packet_type = nicvf_rx_classify_pkt(cqe_rx_w0);
        nicvf_rx_offload(cqe_rx_w0, cqe_rx_w2, pkt);
 
@@ -518,9 +512,7 @@ nicvf_process_cq_mseg_entry(struct cqe_rx_t *cqe_rx,
 
                prev->next = seg;
                seg->data_len = rb_sz[nicvf_frag_num(seg_idx)];
-               seg->port = port_id;
-               seg->data_off = RTE_PKTMBUF_HEADROOM;
-               rte_mbuf_refcnt_set(seg, 1);
+               nicvf_mbuff_init_update(seg, mbuf_init, 0);
 
                prev = seg;
        }
@@ -541,7 +533,7 @@ nicvf_recv_pkts_multiseg(void *rx_queue, struct rte_mbuf **rx_pkts,
        uint32_t i, to_process, cqe_head, buffers_consumed = 0;
        int32_t available_space = rxq->available_space;
        uint16_t nb_segs;
-       const uint8_t port_id = rxq->port_id;
+       const uint64_t mbuf_init = rxq->mbuf_initializer.value;
        const uint8_t rbptr_offset = rxq->rbptr_offset;
 
        cqe_head = rxq->head & cqe_mask;
@@ -552,7 +544,7 @@ nicvf_recv_pkts_multiseg(void *rx_queue, struct rte_mbuf **rx_pkts,
                cq_entry = &desc[cqe_head];
                cqe_rx = (struct cqe_rx_t *)cq_entry;
                nb_segs = nicvf_process_cq_mseg_entry(cqe_rx, mbuf_phys_off,
-                               port_id, rx_pkts + i, rbptr_offset);
+                       rx_pkts + i, rbptr_offset, mbuf_init);
                buffers_consumed += nb_segs;
                cqe_head = (cqe_head + 1) & cqe_mask;
                nicvf_prefetch_store_keep(rx_pkts[i]);

diff --git a/drivers/net/thunderx/nicvf_rxtx.h b/drivers/net/thunderx/nicvf_rxtx.h
index 9dad8a5..3631ff2 100644 (file)
--- a/drivers/net/thunderx/nicvf_rxtx.h
+++ b/drivers/net/thunderx/nicvf_rxtx.h
@@ -84,6 +84,33 @@ fill_sq_desc_gather(union sq_entry_t *entry, struct rte_mbuf *pkt)
 }
 #endif
 
+static inline void
+nicvf_mbuff_init_update(struct rte_mbuf *pkt, const uint64_t mbuf_init,
+                               uint16_t apad)
+{
+       union mbuf_initializer init = {.value = mbuf_init};
+#if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
+       init.fields.data_off += apad;
+#else
+       init.value += apad;
+#endif
+       *(uint64_t *)(&pkt->rearm_data) = init.value;
+}
+
+static inline void
+nicvf_mbuff_init_mseg_update(struct rte_mbuf *pkt, const uint64_t mbuf_init,
+                                               uint16_t apad, uint16_t nb_segs)
+{
+       union mbuf_initializer init = {.value = mbuf_init};
+#if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
+       init.fields.data_off += apad;
+#else
+       init.value += apad;
+#endif
+       init.fields.nb_segs = nb_segs;
+       *(uint64_t *)(&pkt->rearm_data) = init.value;
+}
+
 uint32_t nicvf_dev_rx_queue_count(struct rte_eth_dev *dev, uint16_t queue_idx);
 uint32_t nicvf_dev_rbdr_refill(struct rte_eth_dev *dev, uint16_t queue_idx);
 

diff --git a/drivers/net/thunderx/nicvf_struct.h b/drivers/net/thunderx/nicvf_struct.h
index 5bc6d57..34c41b7 100644 (file)
--- a/drivers/net/thunderx/nicvf_struct.h
+++ b/drivers/net/thunderx/nicvf_struct.h
@@ -72,10 +72,21 @@ struct nicvf_txq {
        uint16_t tx_free_thresh;
 } __rte_cache_aligned;
 
+union mbuf_initializer {
+       struct {
+               uint16_t data_off;
+               uint16_t refcnt;
+               uint16_t nb_segs;
+               uint16_t port;
+       } fields;
+       uint64_t value;
+};
+
 struct nicvf_rxq {
        uint64_t mbuf_phys_off;
        uintptr_t cq_status;
        uintptr_t cq_door;
+       union mbuf_initializer mbuf_initializer;
        nicvf_phys_addr_t phys;
        union cq_entry_t *desc;
        struct nicvf_rbdr *shared_rbdr;