net: rswitch: Add jumbo frames handling for RX

If this hardware receives a jumbo frame like 2KiB or more, it will be
split into multiple queues. In the near future, to support this,
add handling specific descriptor types F{START,MID,END}. However, such
jumbo frames will not happen yet because the maximum MTU size is still
default for now.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c
index 6bd76a88bd40ef539009c35fa672a764c25a4a0b..36c70131594d55b059ba5bbea435c0a25b5216d8 100644 (file)
--- a/drivers/net/ethernet/renesas/rswitch.c
+++ b/drivers/net/ethernet/renesas/rswitch.c
@@ -714,6 +714,80 @@ static int rswitch_gwca_halt(struct rswitch_private *priv)
        return err;
 }
 
+static struct sk_buff *rswitch_rx_handle_desc(struct net_device *ndev,
+                                             struct rswitch_gwca_queue *gq,
+                                             struct rswitch_ext_ts_desc *desc)
+{
+       dma_addr_t dma_addr = rswitch_desc_get_dptr(&desc->desc);
+       u16 pkt_len = le16_to_cpu(desc->desc.info_ds) & RX_DS;
+       u8 die_dt = desc->desc.die_dt & DT_MASK;
+       struct sk_buff *skb = NULL;
+
+       dma_unmap_single(ndev->dev.parent, dma_addr, RSWITCH_MAP_BUF_SIZE,
+                        DMA_FROM_DEVICE);
+
+       /* The RX descriptor order will be one of the following:
+        * - FSINGLE
+        * - FSTART -> FEND
+        * - FSTART -> FMID -> FEND
+        */
+
+       /* Check whether the descriptor is unexpected order */
+       switch (die_dt) {
+       case DT_FSTART:
+       case DT_FSINGLE:
+               if (gq->skb_fstart) {
+                       dev_kfree_skb_any(gq->skb_fstart);
+                       gq->skb_fstart = NULL;
+                       ndev->stats.rx_dropped++;
+               }
+               break;
+       case DT_FMID:
+       case DT_FEND:
+               if (!gq->skb_fstart) {
+                       ndev->stats.rx_dropped++;
+                       return NULL;
+               }
+               break;
+       default:
+               break;
+       }
+
+       /* Handle the descriptor */
+       switch (die_dt) {
+       case DT_FSTART:
+       case DT_FSINGLE:
+               skb = build_skb(gq->rx_bufs[gq->cur], RSWITCH_BUF_SIZE);
+               if (skb) {
+                       skb_reserve(skb, RSWITCH_HEADROOM);
+                       skb_put(skb, pkt_len);
+                       gq->pkt_len = pkt_len;
+                       if (die_dt == DT_FSTART) {
+                               gq->skb_fstart = skb;
+                               skb = NULL;
+                       }
+               }
+               break;
+       case DT_FMID:
+       case DT_FEND:
+               skb_add_rx_frag(gq->skb_fstart, skb_shinfo(gq->skb_fstart)->nr_frags,
+                               virt_to_page(gq->rx_bufs[gq->cur]),
+                               offset_in_page(gq->rx_bufs[gq->cur]) + RSWITCH_HEADROOM,
+                               pkt_len, RSWITCH_BUF_SIZE);
+               if (die_dt == DT_FEND) {
+                       skb = gq->skb_fstart;
+                       gq->skb_fstart = NULL;
+               }
+               gq->pkt_len += pkt_len;
+               break;
+       default:
+               netdev_err(ndev, "%s: unexpected value (%x)\n", __func__, die_dt);
+               break;
+       }
+
+       return skb;
+}
+
 static bool rswitch_rx(struct net_device *ndev, int *quota)
 {
        struct rswitch_device *rdev = netdev_priv(ndev);
@@ -721,9 +795,7 @@ static bool rswitch_rx(struct net_device *ndev, int *quota)
        struct rswitch_ext_ts_desc *desc;
        int limit, boguscnt, ret;
        struct sk_buff *skb;
-       dma_addr_t dma_addr;
        unsigned int num;
-       u16 pkt_len;
        u32 get_ts;
 
        if (*quota <= 0)
@@ -735,15 +807,9 @@ static bool rswitch_rx(struct net_device *ndev, int *quota)
        desc = &gq->rx_ring[gq->cur];
        while ((desc->desc.die_dt & DT_MASK) != DT_FEMPTY) {
                dma_rmb();
-               pkt_len = le16_to_cpu(desc->desc.info_ds) & RX_DS;
-               dma_addr = rswitch_desc_get_dptr(&desc->desc);
-               dma_unmap_single(ndev->dev.parent, dma_addr,
-                                RSWITCH_MAP_BUF_SIZE, DMA_FROM_DEVICE);
-               skb = build_skb(gq->rx_bufs[gq->cur], RSWITCH_BUF_SIZE);
+               skb = rswitch_rx_handle_desc(ndev, gq, desc);
                if (!skb)
                        goto out;
-               skb_reserve(skb, RSWITCH_HEADROOM);
-               skb_put(skb, pkt_len);
 
                get_ts = rdev->priv->ptp_priv->tstamp_rx_ctrl & RCAR_GEN4_RXTSTAMP_TYPE_V2_L2_EVENT;
                if (get_ts) {
@@ -759,7 +825,7 @@ static bool rswitch_rx(struct net_device *ndev, int *quota)
                skb->protocol = eth_type_trans(skb, ndev);
                napi_gro_receive(&rdev->napi, skb);
                rdev->ndev->stats.rx_packets++;
-               rdev->ndev->stats.rx_bytes += pkt_len;
+               rdev->ndev->stats.rx_bytes += gq->pkt_len;
 
 out:
                gq->rx_bufs[gq->cur] = NULL;

diff --git a/drivers/net/ethernet/renesas/rswitch.h b/drivers/net/ethernet/renesas/rswitch.h
index 17e617ec4187b2c48f243c2942ef3864a0f3b278..4252677e2a55432b4f60276812f45782a72a0d37 100644 (file)
--- a/drivers/net/ethernet/renesas/rswitch.h
+++ b/drivers/net/ethernet/renesas/rswitch.h
@@ -965,6 +965,8 @@ struct rswitch_gwca_queue {
                /* For RX */
                struct {
                        void **rx_bufs;
+                       struct sk_buff *skb_fstart;
+                       u16 pkt_len;
                };
        };
 };