[PATCH net-next v14 07/13] rtase: Implement a function to receive packets

Justin Lai
2023-12-08T09:48:28Z

Implement rx_handler to read the information of the rx descriptor,
thereby checking the packet accordingly and storing the packet
in the socket buffer to complete the reception of the packet.

Signed-off-by: Justin Lai <justinlai0215@realtek.com>
---
.../net/ethernet/realtek/rtase/rtase_main.c | 148 ++++++++++++++++++
1 file changed, 148 insertions(+)

diff --git a/drivers/net/ethernet/realtek/rtase/rtase_main.c b/drivers/net/ethernet/realtek/rtase/rtase_main.c
index eee792ea4760..83a119389110 100644
--- a/drivers/net/ethernet/realtek/rtase/rtase_main.c
+++ b/drivers/net/ethernet/realtek/rtase/rtase_main.c
@@ -451,6 +451,154 @@ static void rtase_rx_ring_clear(struct rtase_ring *ring)
}
}

+static int rtase_fragmented_frame(u32 status)
+{
+ return (status & (RX_FIRST_FRAG | RX_LAST_FRAG)) !=
+ (RX_FIRST_FRAG | RX_LAST_FRAG);
+}
+
+static void rtase_rx_csum(const struct rtase_private *tp, struct sk_buff *skb,
+ const union rx_desc *desc)
+{
+ u32 opts2 = le32_to_cpu(desc->desc_status.opts2);
+
+ /* rx csum offload */
+ if (((opts2 & RX_V4F) && !(opts2 & RX_IPF)) || (opts2 & RX_V6F)) {
+ if (((opts2 & RX_TCPT) && !(opts2 & RX_TCPF)) ||
+ ((opts2 & RX_UDPT) && !(opts2 & RX_UDPF))) {
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ } else {
+ skb->ip_summed = CHECKSUM_NONE;
+ }
+ } else {
+ skb->ip_summed = CHECKSUM_NONE;
+ }
+}
+
+static void rtase_rx_vlan_skb(union rx_desc *desc, struct sk_buff *skb)
+{
+ u32 opts2 = le32_to_cpu(desc->desc_status.opts2);
+
+ if (!(opts2 & RX_VLAN_TAG))
+ return;
+
+ __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), swab16(opts2 & VLAN_TAG_MASK));
+}
+
+static void rtase_rx_skb(const struct rtase_ring *ring, struct sk_buff *skb)
+{
+ struct rtase_int_vector *ivec = ring->ivec;
+
+ napi_gro_receive(&ivec->napi, skb);
+}
+
+static int rx_handler(struct rtase_ring *ring, int budget)
+{
+ const struct rtase_private *tp = ring->ivec->tp;
+ u32 pkt_size, cur_rx, delta, entry, status;
+ union rx_desc *desc_base = ring->desc;
+ struct net_device *dev = tp->dev;
+ struct sk_buff *skb;
+ union rx_desc *desc;
+ int workdone = 0;
+
+ if (!ring->desc)
+ return workdone;
+
+ cur_rx = ring->cur_idx;
+ entry = cur_rx % NUM_DESC;
+ desc = &desc_base[entry];
+
+ do {
+ /* make sure discriptor has been updated */
+ rmb();
+ status = le32_to_cpu(desc->desc_status.opts1);
+
+ if (status & DESC_OWN)
+ break;
+
+ if (unlikely(status & RX_RES)) {
+ if (net_ratelimit())
+ netdev_warn(dev, "Rx ERROR. status = %08x\n",
+ status);
+
+ dev->stats.rx_errors++;
+
+ if (status & (RX_RWT | RX_RUNT))
+ dev->stats.rx_length_errors++;
+
+ if (status & RX_CRC)
+ dev->stats.rx_crc_errors++;
+
+ if (dev->features & NETIF_F_RXALL)
+ goto process_pkt;
+
+ rtase_mark_to_asic(desc, tp->rx_buf_sz);
+ goto skip_process_pkt;
+ }
+
+process_pkt:
+ pkt_size = status & RX_PKT_SIZE_MASK;
+ if (likely(!(dev->features & NETIF_F_RXFCS)))
+ pkt_size -= ETH_FCS_LEN;
+
+ /* the driver does not support incoming fragmented
+ * frames. they are seen as a symptom of over-mtu
+ * sized frames
+ */
+ if (unlikely(rtase_fragmented_frame(status))) {
+ dev->stats.rx_dropped++;
+ dev->stats.rx_length_errors++;
+ rtase_mark_to_asic(desc, tp->rx_buf_sz);
+ continue;
+ }
+
+ skb = ring->skbuff[entry];
+ dma_sync_single_for_cpu(&tp->pdev->dev,
+ ring->mis.data_phy_addr[entry],
+ tp->rx_buf_sz, DMA_FROM_DEVICE);
+
+ ring->skbuff[entry] = NULL;
+
+ if (dev->features & NETIF_F_RXCSUM)
+ rtase_rx_csum(tp, skb, desc);
+
+ skb->dev = dev;
+ skb_put(skb, pkt_size);
+ skb_mark_for_recycle(skb);
+ skb->protocol = eth_type_trans(skb, dev);
+
+ if (skb->pkt_type == PACKET_MULTICAST)
+ dev->stats.multicast++;
+
+ rtase_rx_vlan_skb(desc, skb);
+ rtase_rx_skb(ring, skb);
+
+ dev->stats.rx_bytes += pkt_size;
+ dev->stats.rx_packets++;
+
+skip_process_pkt:
+ workdone++;
+ cur_rx++;
+ entry = cur_rx % NUM_DESC;
+ desc = ring->desc + sizeof(union rx_desc) * entry;
+ prefetch(desc);
+ } while (workdone != budget);
+
+ ring->cur_idx = cur_rx;
+ delta = rtase_rx_ring_fill(ring, ring->dirty_idx, ring->cur_idx, 1);
+
+ if (!delta && workdone)
+ netdev_info(dev, "no Rx buffer allocated\n");
+
+ ring->dirty_idx += delta;
+
+ if ((ring->dirty_idx + NUM_DESC) == ring->cur_idx)
+ netdev_emerg(dev, "Rx buffers exhausted\n");
+
+ return workdone;
+}
+
static void rtase_rx_desc_init(struct rtase_private *tp, u16 idx)
{
struct rtase_ring *ring = &tp->rx_ring[idx];
--
2.34.1