net/sfc: remove Tx DMA descriptor boundary crossing limit

EF10 supported by the PMD has no limitations on address boundary
crossing by Tx DMA descriptors.

Fixes: 428c7ddd2f16 ("net/sfc: send bursts of packets")
Fixes: fec33d5bb3eb ("net/sfc: support firmware-assisted TSO")

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>

diff --git a/drivers/net/sfc/sfc_tso.c b/drivers/net/sfc/sfc_tso.c
index 68d84c9..d3398b1 100644 (file)
--- a/drivers/net/sfc/sfc_tso.c
+++ b/drivers/net/sfc/sfc_tso.c
@@ -50,7 +50,7 @@ sfc_tso_alloc_tsoh_objs(struct sfc_tx_sw_desc *sw_ring,
        for (i = 0; i < txq_entries; ++i) {
                sw_ring[i].tsoh = rte_malloc_socket("sfc-txq-tsoh-obj",
                                                    SFC_TSOH_STD_LEN,
-                                                   SFC_TX_SEG_BOUNDARY,
+                                                   RTE_CACHE_LINE_SIZE,
                                                    socket_id);
                if (sw_ring[i].tsoh == NULL)
                        goto fail_alloc_tsoh_objs;
@@ -116,7 +116,6 @@ sfc_tso_do(struct sfc_txq *txq, unsigned int idx, struct rte_mbuf **in_seg,
        uint8_t *tsoh;
        const struct tcp_hdr *th;
        efsys_dma_addr_t header_paddr;
-       efsys_dma_addr_t paddr_next_frag;
        uint16_t packet_id;
        uint32_t sent_seq;
        struct rte_mbuf *m = *in_seg;
@@ -140,17 +139,15 @@ sfc_tso_do(struct sfc_txq *txq, unsigned int idx, struct rte_mbuf **in_seg,
                return EMSGSIZE;
 
        header_paddr = rte_pktmbuf_mtophys(m);
-       paddr_next_frag = P2ROUNDUP(header_paddr + 1, SFC_TX_SEG_BOUNDARY);
 
        /*
         * Sometimes headers may be split across multiple mbufs. In such cases
         * we need to glue those pieces and store them in some temporary place.
         * Also, packet headers must be contiguous in memory, so that
-        * they can be referred to with a single DMA descriptor. Hence, handle
-        * the case where the original header crosses a 4K memory boundary
+        * they can be referred to with a single DMA descriptor. EF10 has no
+        * limitations on address boundaries crossing by DMA descriptor data.
         */
-       if ((m->data_len < header_len) ||
-           ((paddr_next_frag - header_paddr) < header_len)) {
+       if (m->data_len < header_len) {
                sfc_tso_prepare_header(txq, in_seg, in_off, idx, header_len);
                tsoh = txq->sw_ring[idx & txq->ptr_mask].tsoh;
 

diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
index 5a6282c..5bb31ad 100644 (file)
--- a/drivers/net/sfc/sfc_tx.c
+++ b/drivers/net/sfc/sfc_tx.c
@@ -137,6 +137,7 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
             uint16_t nb_tx_desc, unsigned int socket_id,
             const struct rte_eth_txconf *tx_conf)
 {
+       const efx_nic_cfg_t *encp = efx_nic_cfg_get(sa->nic);
        struct sfc_txq_info *txq_info;
        struct sfc_evq *evq;
        struct sfc_txq *txq;
@@ -195,6 +196,7 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
        txq->ptr_mask = txq_info->entries - 1;
        txq->free_thresh = (tx_conf->tx_free_thresh) ? tx_conf->tx_free_thresh :
                                                     SFC_TX_DEFAULT_FREE_THRESH;
+       txq->dma_desc_size_max = encp->enc_tx_dma_desc_size_max;
        txq->hw_index = sw_index;
        txq->flags = tx_conf->txq_flags;
        txq->evq = evq;
@@ -302,10 +304,21 @@ sfc_tx_check_mode(struct sfc_adapter *sa, const struct rte_eth_txmode *txmode)
 int
 sfc_tx_init(struct sfc_adapter *sa)
 {
+       const efx_nic_cfg_t *encp = efx_nic_cfg_get(sa->nic);
        const struct rte_eth_conf *dev_conf = &sa->eth_dev->data->dev_conf;
        unsigned int sw_index;
        int rc = 0;
 
+       /*
+        * The datapath implementation assumes absence of boundary
+        * limits on Tx DMA descriptors. Addition of these checks on
+        * datapath would simply make the datapath slower.
+        */
+       if (encp->enc_tx_dma_desc_boundary != 0) {
+               rc = ENOTSUP;
+               goto fail_tx_dma_desc_boundary;
+       }
+
        rc = sfc_tx_check_mode(sa, &dev_conf->txmode);
        if (rc != 0)
                goto fail_check_mode;
@@ -334,6 +347,7 @@ fail_txqs_alloc:
        sa->txq_count = 0;
 
 fail_check_mode:
+fail_tx_dma_desc_boundary:
        sfc_log_init(sa, "failed (rc = %d)", rc);
        return rc;
 }
@@ -704,9 +718,13 @@ sfc_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
                                efsys_dma_addr_t        frag_addr = next_frag;
                                size_t                  frag_len;
 
-                               next_frag = RTE_ALIGN(frag_addr + 1,
-                                                     SFC_TX_SEG_BOUNDARY);
-                               frag_len = MIN(next_frag - frag_addr, seg_len);
+                               /*
+                                * It is assumed here that there is no
+                                * limitation on address boundary
+                                * crossing by DMA descriptor.
+                                */
+                               frag_len = MIN(seg_len, txq->dma_desc_size_max);
+                               next_frag += frag_len;
                                seg_len -= frag_len;
                                pkt_len -= frag_len;
 

diff --git a/drivers/net/sfc/sfc_tx.h b/drivers/net/sfc/sfc_tx.h
index 39977a5..700e92b 100644 (file)
--- a/drivers/net/sfc/sfc_tx.h
+++ b/drivers/net/sfc/sfc_tx.h
@@ -39,12 +39,6 @@
 extern "C" {
 #endif
 
-/**
- * A segment must not cross 4K boundary
- * (this is a requirement of NIC TX descriptors)
- */
-#define SFC_TX_SEG_BOUNDARY    4096
-
 struct sfc_adapter;
 struct sfc_evq;
 
@@ -79,6 +73,7 @@ struct sfc_txq {
        unsigned int            completed;
        unsigned int            free_thresh;
        uint16_t                hw_vlan_tci;
+       uint16_t                dma_desc_size_max;
 
        unsigned int            hw_index;
        unsigned int            flags;