mvpp2: XDP TX support
authorMatteo Croce <mcroce@microsoft.com>
Thu, 2 Jul 2020 14:12:43 +0000 (16:12 +0200)
committerDavid S. Miller <davem@davemloft.net>
Fri, 3 Jul 2020 21:46:24 +0000 (14:46 -0700)
Add the transmit part of XDP support, which includes:
- support for XDP_TX in mvpp2_xdp()
- .ndo_xdp_xmit hook for AF_XDP and XDP_REDIRECT with mvpp2 as destination

mvpp2_xdp_submit_frame() is a generic function which is called by
mvpp2_xdp_xmit_back() when doing XDP_TX, and by mvpp2_xdp_xmit when
doing AF_XDP or XDP_REDIRECT target.

The buffer allocation has been reworked to be able to map the buffers
as DMA_FROM_DEVICE or DMA_BIDIRECTIONAL depending if native XDP is
in use or not.

Co-developed-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/marvell/mvpp2/mvpp2.h
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

index f351e41..c52955b 100644 (file)
@@ -1082,9 +1082,20 @@ struct mvpp2_rx_desc {
        };
 };
 
+enum mvpp2_tx_buf_type {
+       MVPP2_TYPE_SKB,
+       MVPP2_TYPE_XDP_TX,
+       MVPP2_TYPE_XDP_NDO,
+};
+
 struct mvpp2_txq_pcpu_buf {
+       enum mvpp2_tx_buf_type type;
+
        /* Transmitted SKB */
-       struct sk_buff *skb;
+       union {
+               struct xdp_frame *xdpf;
+               struct sk_buff *skb;
+       };
 
        /* Physical address of transmitted buffer */
        dma_addr_t dma;
index 5f740c9..d49a814 100644 (file)
@@ -97,7 +97,8 @@ static inline u32 mvpp2_cpu_to_thread(struct mvpp2 *priv, int cpu)
 }
 
 static struct page_pool *
-mvpp2_create_page_pool(struct device *dev, int num, int len)
+mvpp2_create_page_pool(struct device *dev, int num, int len,
+                      enum dma_data_direction dma_dir)
 {
        struct page_pool_params pp_params = {
                /* internal DMA mapping in page_pool */
@@ -105,7 +106,7 @@ mvpp2_create_page_pool(struct device *dev, int num, int len)
                .pool_size = num,
                .nid = NUMA_NO_NODE,
                .dev = dev,
-               .dma_dir = DMA_FROM_DEVICE,
+               .dma_dir = dma_dir,
                .offset = MVPP2_SKB_HEADROOM,
                .max_len = len,
        };
@@ -299,12 +300,17 @@ static void mvpp2_txq_inc_get(struct mvpp2_txq_pcpu *txq_pcpu)
 
 static void mvpp2_txq_inc_put(struct mvpp2_port *port,
                              struct mvpp2_txq_pcpu *txq_pcpu,
-                             struct sk_buff *skb,
-                             struct mvpp2_tx_desc *tx_desc)
+                             void *data,
+                             struct mvpp2_tx_desc *tx_desc,
+                             enum mvpp2_tx_buf_type buf_type)
 {
        struct mvpp2_txq_pcpu_buf *tx_buf =
                txq_pcpu->buffs + txq_pcpu->txq_put_index;
-       tx_buf->skb = skb;
+       tx_buf->type = buf_type;
+       if (buf_type == MVPP2_TYPE_SKB)
+               tx_buf->skb = data;
+       else
+               tx_buf->xdpf = data;
        tx_buf->size = mvpp2_txdesc_size_get(port, tx_desc);
        tx_buf->dma = mvpp2_txdesc_dma_addr_get(port, tx_desc) +
                mvpp2_txdesc_offset_get(port, tx_desc);
@@ -527,9 +533,6 @@ static int mvpp2_bm_pool_destroy(struct device *dev, struct mvpp2 *priv,
        int buf_num;
        u32 val;
 
-       if (priv->percpu_pools)
-               page_pool_destroy(priv->page_pool[bm_pool->id]);
-
        buf_num = mvpp2_check_hw_buf_num(priv, bm_pool);
        mvpp2_bm_bufs_free(dev, priv, bm_pool, buf_num);
 
@@ -545,6 +548,9 @@ static int mvpp2_bm_pool_destroy(struct device *dev, struct mvpp2 *priv,
        val |= MVPP2_BM_STOP_MASK;
        mvpp2_write(priv, MVPP2_BM_POOL_CTRL_REG(bm_pool->id), val);
 
+       if (priv->percpu_pools)
+               page_pool_destroy(priv->page_pool[bm_pool->id]);
+
        dma_free_coherent(dev, bm_pool->size_bytes,
                          bm_pool->virt_addr,
                          bm_pool->dma_addr);
@@ -580,9 +586,19 @@ err_unroll_pools:
 
 static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
 {
+       enum dma_data_direction dma_dir = DMA_FROM_DEVICE;
        int i, err, poolnum = MVPP2_BM_POOLS_NUM;
+       struct mvpp2_port *port;
 
        if (priv->percpu_pools) {
+               for (i = 0; i < priv->port_count; i++) {
+                       port = priv->port_list[i];
+                       if (port->xdp_prog) {
+                               dma_dir = DMA_BIDIRECTIONAL;
+                               break;
+                       }
+               }
+
                poolnum = mvpp2_get_nrxqs(priv) * 2;
                for (i = 0; i < poolnum; i++) {
                        /* the pool in use */
@@ -591,7 +607,8 @@ static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
                        priv->page_pool[i] =
                                mvpp2_create_page_pool(dev,
                                                       mvpp2_pools[pn].buf_num,
-                                                      mvpp2_pools[pn].pkt_size);
+                                                      mvpp2_pools[pn].pkt_size,
+                                                      dma_dir);
                        if (IS_ERR(priv->page_pool[i]))
                                return PTR_ERR(priv->page_pool[i]);
                }
@@ -2318,11 +2335,15 @@ static void mvpp2_txq_bufs_free(struct mvpp2_port *port,
                struct mvpp2_txq_pcpu_buf *tx_buf =
                        txq_pcpu->buffs + txq_pcpu->txq_get_index;
 
-               if (!IS_TSO_HEADER(txq_pcpu, tx_buf->dma))
+               if (!IS_TSO_HEADER(txq_pcpu, tx_buf->dma) &&
+                   tx_buf->type != MVPP2_TYPE_XDP_TX)
                        dma_unmap_single(port->dev->dev.parent, tx_buf->dma,
                                         tx_buf->size, DMA_TO_DEVICE);
-               if (tx_buf->skb)
+               if (tx_buf->type == MVPP2_TYPE_SKB && tx_buf->skb)
                        dev_kfree_skb_any(tx_buf->skb);
+               else if (tx_buf->type == MVPP2_TYPE_XDP_TX ||
+                        tx_buf->type == MVPP2_TYPE_XDP_NDO)
+                       xdp_return_frame(tx_buf->xdpf);
 
                mvpp2_txq_inc_get(txq_pcpu);
        }
@@ -2810,7 +2831,7 @@ err_cleanup:
 static int mvpp2_setup_txqs(struct mvpp2_port *port)
 {
        struct mvpp2_tx_queue *txq;
-       int queue, err, cpu;
+       int queue, err;
 
        for (queue = 0; queue < port->ntxqs; queue++) {
                txq = port->txqs[queue];
@@ -2819,8 +2840,8 @@ static int mvpp2_setup_txqs(struct mvpp2_port *port)
                        goto err_cleanup;
 
                /* Assign this queue to a CPU */
-               cpu = queue % num_present_cpus();
-               netif_set_xps_queue(port->dev, cpumask_of(cpu), queue);
+               if (queue < num_possible_cpus())
+                       netif_set_xps_queue(port->dev, cpumask_of(queue), queue);
        }
 
        if (port->has_tx_irqs) {
@@ -3039,6 +3060,164 @@ static u32 mvpp2_skb_tx_csum(struct mvpp2_port *port, struct sk_buff *skb)
        return MVPP2_TXD_L4_CSUM_NOT | MVPP2_TXD_IP_CSUM_DISABLE;
 }
 
+static void mvpp2_xdp_finish_tx(struct mvpp2_port *port, u16 txq_id, int nxmit, int nxmit_byte)
+{
+       unsigned int thread = mvpp2_cpu_to_thread(port->priv, smp_processor_id());
+       struct mvpp2_pcpu_stats *stats = per_cpu_ptr(port->stats, thread);
+       struct mvpp2_tx_queue *aggr_txq;
+       struct mvpp2_txq_pcpu *txq_pcpu;
+       struct mvpp2_tx_queue *txq;
+       struct netdev_queue *nq;
+
+       txq = port->txqs[txq_id];
+       txq_pcpu = per_cpu_ptr(txq->pcpu, thread);
+       nq = netdev_get_tx_queue(port->dev, txq_id);
+       aggr_txq = &port->priv->aggr_txqs[thread];
+
+       txq_pcpu->reserved_num -= nxmit;
+       txq_pcpu->count += nxmit;
+       aggr_txq->count += nxmit;
+
+       /* Enable transmit */
+       wmb();
+       mvpp2_aggr_txq_pend_desc_add(port, nxmit);
+
+       if (txq_pcpu->count >= txq_pcpu->stop_threshold)
+               netif_tx_stop_queue(nq);
+
+       u64_stats_update_begin(&stats->syncp);
+       stats->tx_bytes += nxmit_byte;
+       stats->tx_packets += nxmit;
+       u64_stats_update_end(&stats->syncp);
+
+       /* Finalize TX processing */
+       if (!port->has_tx_irqs && txq_pcpu->count >= txq->done_pkts_coal)
+               mvpp2_txq_done(port, txq, txq_pcpu);
+}
+
+static int
+mvpp2_xdp_submit_frame(struct mvpp2_port *port, u16 txq_id,
+                      struct xdp_frame *xdpf, bool dma_map)
+{
+       unsigned int thread = mvpp2_cpu_to_thread(port->priv, smp_processor_id());
+       u32 tx_cmd = MVPP2_TXD_L4_CSUM_NOT | MVPP2_TXD_IP_CSUM_DISABLE |
+                    MVPP2_TXD_F_DESC | MVPP2_TXD_L_DESC;
+       enum mvpp2_tx_buf_type buf_type;
+       struct mvpp2_txq_pcpu *txq_pcpu;
+       struct mvpp2_tx_queue *aggr_txq;
+       struct mvpp2_tx_desc *tx_desc;
+       struct mvpp2_tx_queue *txq;
+       int ret = MVPP2_XDP_TX;
+       dma_addr_t dma_addr;
+
+       txq = port->txqs[txq_id];
+       txq_pcpu = per_cpu_ptr(txq->pcpu, thread);
+       aggr_txq = &port->priv->aggr_txqs[thread];
+
+       /* Check number of available descriptors */
+       if (mvpp2_aggr_desc_num_check(port, aggr_txq, 1) ||
+           mvpp2_txq_reserved_desc_num_proc(port, txq, txq_pcpu, 1)) {
+               ret = MVPP2_XDP_DROPPED;
+               goto out;
+       }
+
+       /* Get a descriptor for the first part of the packet */
+       tx_desc = mvpp2_txq_next_desc_get(aggr_txq);
+       mvpp2_txdesc_txq_set(port, tx_desc, txq->id);
+       mvpp2_txdesc_size_set(port, tx_desc, xdpf->len);
+
+       if (dma_map) {
+               /* XDP_REDIRECT or AF_XDP */
+               dma_addr = dma_map_single(port->dev->dev.parent, xdpf->data,
+                                         xdpf->len, DMA_TO_DEVICE);
+
+               if (unlikely(dma_mapping_error(port->dev->dev.parent, dma_addr))) {
+                       mvpp2_txq_desc_put(txq);
+                       ret = MVPP2_XDP_DROPPED;
+                       goto out;
+               }
+
+               buf_type = MVPP2_TYPE_XDP_NDO;
+       } else {
+               /* XDP_TX */
+               struct page *page = virt_to_page(xdpf->data);
+
+               dma_addr = page_pool_get_dma_addr(page) +
+                          sizeof(*xdpf) + xdpf->headroom;
+               dma_sync_single_for_device(port->dev->dev.parent, dma_addr,
+                                          xdpf->len, DMA_BIDIRECTIONAL);
+
+               buf_type = MVPP2_TYPE_XDP_TX;
+       }
+
+       mvpp2_txdesc_dma_addr_set(port, tx_desc, dma_addr);
+
+       mvpp2_txdesc_cmd_set(port, tx_desc, tx_cmd);
+       mvpp2_txq_inc_put(port, txq_pcpu, xdpf, tx_desc, buf_type);
+
+out:
+       return ret;
+}
+
+static int
+mvpp2_xdp_xmit_back(struct mvpp2_port *port, struct xdp_buff *xdp)
+{
+       struct xdp_frame *xdpf;
+       u16 txq_id;
+       int ret;
+
+       xdpf = xdp_convert_buff_to_frame(xdp);
+       if (unlikely(!xdpf))
+               return MVPP2_XDP_DROPPED;
+
+       /* The first of the TX queues are used for XPS,
+        * the second half for XDP_TX
+        */
+       txq_id = mvpp2_cpu_to_thread(port->priv, smp_processor_id()) + (port->ntxqs / 2);
+
+       ret = mvpp2_xdp_submit_frame(port, txq_id, xdpf, false);
+       if (ret == MVPP2_XDP_TX)
+               mvpp2_xdp_finish_tx(port, txq_id, 1, xdpf->len);
+
+       return ret;
+}
+
+static int
+mvpp2_xdp_xmit(struct net_device *dev, int num_frame,
+              struct xdp_frame **frames, u32 flags)
+{
+       struct mvpp2_port *port = netdev_priv(dev);
+       int i, nxmit_byte = 0, nxmit = num_frame;
+       u16 txq_id;
+       u32 ret;
+
+       if (unlikely(test_bit(0, &port->state)))
+               return -ENETDOWN;
+
+       if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+               return -EINVAL;
+
+       /* The first of the TX queues are used for XPS,
+        * the second half for XDP_TX
+        */
+       txq_id = mvpp2_cpu_to_thread(port->priv, smp_processor_id()) + (port->ntxqs / 2);
+
+       for (i = 0; i < num_frame; i++) {
+               ret = mvpp2_xdp_submit_frame(port, txq_id, frames[i], true);
+               if (ret == MVPP2_XDP_TX) {
+                       nxmit_byte += frames[i]->len;
+               } else {
+                       xdp_return_frame_rx_napi(frames[i]);
+                       nxmit--;
+               }
+       }
+
+       if (nxmit > 0)
+               mvpp2_xdp_finish_tx(port, txq_id, nxmit, nxmit_byte);
+
+       return nxmit;
+}
+
 static int
 mvpp2_run_xdp(struct mvpp2_port *port, struct mvpp2_rx_queue *rxq,
              struct bpf_prog *prog, struct xdp_buff *xdp,
@@ -3069,6 +3248,13 @@ mvpp2_run_xdp(struct mvpp2_port *port, struct mvpp2_rx_queue *rxq,
                        ret = MVPP2_XDP_REDIR;
                }
                break;
+       case XDP_TX:
+               ret = mvpp2_xdp_xmit_back(port, xdp);
+               if (ret != MVPP2_XDP_TX) {
+                       page = virt_to_head_page(xdp->data);
+                       page_pool_put_page(pp, page, sync, true);
+               }
+               break;
        default:
                bpf_warn_invalid_xdp_action(act);
                fallthrough;
@@ -3090,6 +3276,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
                    int rx_todo, struct mvpp2_rx_queue *rxq)
 {
        struct net_device *dev = port->dev;
+       enum dma_data_direction dma_dir;
        struct bpf_prog *xdp_prog;
        struct xdp_buff xdp;
        int rx_received;
@@ -3139,13 +3326,19 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
                if (rx_status & MVPP2_RXD_ERR_SUMMARY)
                        goto err_drop_frame;
 
+               if (port->priv->percpu_pools) {
+                       pp = port->priv->page_pool[pool];
+                       dma_dir = page_pool_get_dma_dir(pp);
+               } else {
+                       dma_dir = DMA_FROM_DEVICE;
+               }
+
                dma_sync_single_for_cpu(dev->dev.parent, dma_addr,
                                        rx_bytes + MVPP2_MH_SIZE,
-                                       DMA_FROM_DEVICE);
-               prefetch(data);
+                                       dma_dir);
 
-               if (port->priv->percpu_pools)
-                       pp = port->priv->page_pool[pool];
+               /* Prefetch header */
+               prefetch(data);
 
                if (bm_pool->frag_size > PAGE_SIZE)
                        frag_size = 0;
@@ -3218,6 +3411,9 @@ err_drop_frame:
 
        rcu_read_unlock();
 
+       if (xdp_ret & MVPP2_XDP_REDIR)
+               xdp_do_flush_map();
+
        if (rcvd_pkts) {
                struct mvpp2_pcpu_stats *stats = this_cpu_ptr(port->stats);
 
@@ -3284,11 +3480,11 @@ static int mvpp2_tx_frag_process(struct mvpp2_port *port, struct sk_buff *skb,
                        /* Last descriptor */
                        mvpp2_txdesc_cmd_set(port, tx_desc,
                                             MVPP2_TXD_L_DESC);
-                       mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc);
+                       mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc, MVPP2_TYPE_SKB);
                } else {
                        /* Descriptor in the middle: Not First, Not Last */
                        mvpp2_txdesc_cmd_set(port, tx_desc, 0);
-                       mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+                       mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);
                }
        }
 
@@ -3326,7 +3522,7 @@ static inline void mvpp2_tso_put_hdr(struct sk_buff *skb,
        mvpp2_txdesc_cmd_set(port, tx_desc, mvpp2_skb_tx_csum(port, skb) |
                                            MVPP2_TXD_F_DESC |
                                            MVPP2_TXD_PADDING_DISABLE);
-       mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+       mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);
 }
 
 static inline int mvpp2_tso_put_data(struct sk_buff *skb,
@@ -3355,14 +3551,14 @@ static inline int mvpp2_tso_put_data(struct sk_buff *skb,
        if (!left) {
                mvpp2_txdesc_cmd_set(port, tx_desc, MVPP2_TXD_L_DESC);
                if (last) {
-                       mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc);
+                       mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc, MVPP2_TYPE_SKB);
                        return 0;
                }
        } else {
                mvpp2_txdesc_cmd_set(port, tx_desc, 0);
        }
 
-       mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+       mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);
        return 0;
 }
 
@@ -3475,12 +3671,12 @@ static netdev_tx_t mvpp2_tx(struct sk_buff *skb, struct net_device *dev)
                /* First and Last descriptor */
                tx_cmd |= MVPP2_TXD_F_DESC | MVPP2_TXD_L_DESC;
                mvpp2_txdesc_cmd_set(port, tx_desc, tx_cmd);
-               mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc);
+               mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc, MVPP2_TYPE_SKB);
        } else {
                /* First but not Last */
                tx_cmd |= MVPP2_TXD_F_DESC | MVPP2_TXD_PADDING_DISABLE;
                mvpp2_txdesc_cmd_set(port, tx_desc, tx_cmd);
-               mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+               mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);
 
                /* Continue with other skb fragments */
                if (mvpp2_tx_frag_process(port, skb, aggr_txq, txq)) {
@@ -4159,6 +4355,33 @@ static int mvpp2_change_mtu(struct net_device *dev, int mtu)
        return err;
 }
 
+static int mvpp2_check_pagepool_dma(struct mvpp2_port *port)
+{
+       enum dma_data_direction dma_dir = DMA_FROM_DEVICE;
+       struct mvpp2 *priv = port->priv;
+       int err = -1, i;
+
+       if (!priv->percpu_pools)
+               return err;
+
+       if (!priv->page_pool)
+               return -ENOMEM;
+
+       for (i = 0; i < priv->port_count; i++) {
+               port = priv->port_list[i];
+               if (port->xdp_prog) {
+                       dma_dir = DMA_BIDIRECTIONAL;
+                       break;
+               }
+       }
+
+       /* All pools are equal in terms of DMA direction */
+       if (priv->page_pool[0]->p.dma_dir != dma_dir)
+               err = mvpp2_bm_switch_buffers(priv, true);
+
+       return err;
+}
+
 static void
 mvpp2_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 {
@@ -4268,13 +4491,15 @@ static int mvpp2_xdp_setup(struct mvpp2_port *port, struct netdev_bpf *bpf)
                return -EOPNOTSUPP;
        }
 
-       /* device is up and bpf is added/removed, must setup the RX queues */
-       if (running && reset) {
-               mvpp2_stop_dev(port);
-               mvpp2_cleanup_rxqs(port);
-               mvpp2_cleanup_txqs(port);
+       if (port->ntxqs < num_possible_cpus() * 2) {
+               NL_SET_ERR_MSG_MOD(bpf->extack, "XDP_TX needs two TX queues per CPU");
+               return -EOPNOTSUPP;
        }
 
+       /* device is up and bpf is added/removed, must setup the RX queues */
+       if (running && reset)
+               mvpp2_stop(port->dev);
+
        old_prog = xchg(&port->xdp_prog, prog);
        if (old_prog)
                bpf_prog_put(old_prog);
@@ -4284,21 +4509,11 @@ static int mvpp2_xdp_setup(struct mvpp2_port *port, struct netdev_bpf *bpf)
                return 0;
 
        /* device was up, restore the link */
-       if (running) {
-               int ret = mvpp2_setup_rxqs(port);
-
-               if (ret) {
-                       netdev_err(port->dev, "mvpp2_setup_rxqs failed\n");
-                       return ret;
-               }
-               ret = mvpp2_setup_txqs(port);
-               if (ret) {
-                       netdev_err(port->dev, "mvpp2_setup_txqs failed\n");
-                       return ret;
-               }
+       if (running)
+               mvpp2_open(port->dev);
 
-               mvpp2_start_dev(port);
-       }
+       /* Check Page Pool DMA Direction */
+       mvpp2_check_pagepool_dma(port);
 
        return 0;
 }
@@ -4669,6 +4884,7 @@ static const struct net_device_ops mvpp2_netdev_ops = {
        .ndo_vlan_rx_kill_vid   = mvpp2_vlan_rx_kill_vid,
        .ndo_set_features       = mvpp2_set_features,
        .ndo_bpf                = mvpp2_xdp,
+       .ndo_xdp_xmit           = mvpp2_xdp_xmit,
 };
 
 static const struct ethtool_ops mvpp2_eth_tool_ops = {