Thread (38 messages) 38 messages, 7 authors, 2020-12-23

Re: [RFC PATCH v2 3/8] net: sparx5: add hostmode with phylink support

From: Andrew Lunn <andrew@lunn.ch>
Date: 2020-12-19 19:52:35
Also in: linux-arm-kernel, lkml

quoted hunk ↗ jump to hunk
+	/* Create a phylink for PHY management.  Also handles SFPs */
+	spx5_port->phylink_config.dev = &spx5_port->ndev->dev;
+	spx5_port->phylink_config.type = PHYLINK_NETDEV;
+	spx5_port->phylink_config.pcs_poll = true;
+
+	/* phylink needs a valid interface mode to parse dt node */
+	if (phy_mode == PHY_INTERFACE_MODE_NA)
+		phy_mode = PHY_INTERFACE_MODE_10GBASER;
Maybe just enforce a valid value in DT?
quoted hunk ↗ jump to hunk
+/* Configuration */
+static inline bool sparx5_use_cu_phy(struct sparx5_port *port)
+{
+	return port->conf.phy_mode != PHY_INTERFACE_MODE_NA;
+}
That is a rather odd definition of copper.
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c b/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c
new file mode 100644
index 000000000000..6f9282e9d3f4
--- /dev/null
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Microchip Sparx5 Switch driver
+ *
+ * Copyright (c) 2020 Microchip Technology Inc. and its subsidiaries.
+ */
+
+#include "sparx5_main.h"
I don't actually know what is preferred here, but very few drivers
i've reviewed put all the required headers into another header
file. They normally list them in each .c file.
quoted hunk ↗ jump to hunk
+static int sparx5_port_open(struct net_device *ndev)
+{
+	struct sparx5_port *port = netdev_priv(ndev);
+	int err = 0;
+
+	err = phylink_of_phy_connect(port->phylink, port->of_node, 0);
+	if (err) {
+		netdev_err(ndev, "Could not attach to PHY\n");
+		return err;
+	}
+
+	phylink_start(port->phylink);
+
+	if (!ndev->phydev) {
Humm. When is ndev->phydev set? I don't think phylink ever sets it.
quoted hunk ↗ jump to hunk
+		/* power up serdes */
+		port->conf.power_down = false;
+		err = phy_power_on(port->serdes);
+		if (err)
+			netdev_err(ndev, "%s failed\n", __func__);
+	}
+
+	return err;
+}
quoted hunk ↗ jump to hunk
+struct net_device *sparx5_create_netdev(struct sparx5 *sparx5, u32 portno)
+{
+	struct net_device *ndev;
+	struct sparx5_port *spx5_port;
+
+	ndev = devm_alloc_etherdev(sparx5->dev, sizeof(struct sparx5_port));
+	if (!ndev)
+		return ERR_PTR(-ENOMEM);
+
+	SET_NETDEV_DEV(ndev, sparx5->dev);
+	spx5_port = netdev_priv(ndev);
+	spx5_port->ndev = ndev;
+	spx5_port->sparx5 = sparx5;
+	spx5_port->portno = portno;
+	sparx5_set_port_ifh(spx5_port->ifh, portno);
+	snprintf(ndev->name, IFNAMSIZ, "eth%d", portno);
+
+	ether_setup(ndev);
devm_alloc_etherdev() should of already called ether_setup().
quoted hunk ↗ jump to hunk
+	ndev->netdev_ops = &sparx5_port_netdev_ops;
+	ndev->features |= NETIF_F_LLTX; /* software tx */
+
+	ether_addr_copy(ndev->dev_addr, sparx5->base_mac);
+	ndev->dev_addr[ETH_ALEN - 1] += portno + 1;
That will cause some surprises with wrap around. Use eth_addr_inc()
quoted hunk ↗ jump to hunk
+static void sparx5_xtr_grp(struct sparx5 *sparx5, u8 grp, bool byte_swap)
+{
+	int i, byte_cnt = 0;
+	bool eof_flag = false, pruned_flag = false, abort_flag = false;
+	u32 ifh[IFH_LEN];
+	struct sk_buff *skb;
+	struct frame_info fi;
+	struct sparx5_port *port;
+	struct net_device *netdev;
+	u32 *rxbuf;
+
+	/* Get IFH */
+	for (i = 0; i < IFH_LEN; i++)
+		ifh[i] = spx5_rd(sparx5, QS_XTR_RD(grp));
+
+	/* Decode IFH (whats needed) */
+	sparx5_ifh_parse(ifh, &fi);
+
+	/* Map to port netdev */
+	port = fi.src_port < SPX5_PORTS ?
+		sparx5->ports[fi.src_port] : NULL;
+	if (!port || !port->ndev) {
+		dev_err(sparx5->dev, "Data on inactive port %d\n", fi.src_port);
+		sparx5_xtr_flush(sparx5, grp);
+		return;
+	}
+
+	/* Have netdev, get skb */
+	netdev = port->ndev;
+	skb = netdev_alloc_skb(netdev, netdev->mtu + ETH_HLEN);
+	if (!skb) {
+		sparx5_xtr_flush(sparx5, grp);
+		dev_err(sparx5->dev, "No skb allocated\n");
+		return;
+	}
+	rxbuf = (u32 *)skb->data;
+
+	/* Now, pull frame data */
+	while (!eof_flag) {
+		u32 val = spx5_rd(sparx5, QS_XTR_RD(grp));
+		u32 cmp = val;
+
+		if (byte_swap)
+			cmp = ntohl((__force __be32)val);
+
+		switch (cmp) {
+		case XTR_NOT_READY:
+			break;
+		case XTR_ABORT:
+			/* No accompanying data */
+			abort_flag = true;
+			eof_flag = true;
+			break;
+		case XTR_EOF_0:
+		case XTR_EOF_1:
+		case XTR_EOF_2:
+		case XTR_EOF_3:
+			/* This assumes STATUS_WORD_POS == 1, Status
+			 * just after last data
+			 */
+			byte_cnt -= (4 - XTR_VALID_BYTES(val));
+			eof_flag = true;
+			break;
+		case XTR_PRUNED:
+			/* But get the last 4 bytes as well */
+			eof_flag = true;
+			pruned_flag = true;
+			fallthrough;
+		case XTR_ESCAPE:
+			*rxbuf = spx5_rd(sparx5, QS_XTR_RD(grp));
+			byte_cnt += 4;
+			rxbuf++;
+			break;
+		default:
+			*rxbuf = val;
+			byte_cnt += 4;
+			rxbuf++;
+		}
+	}
+
+	if (abort_flag || pruned_flag || !eof_flag) {
+		netdev_err(netdev, "Discarded frame: abort:%d pruned:%d eof:%d\n",
+			   abort_flag, pruned_flag, eof_flag);
+		kfree_skb(skb);
+		return;
+	}
+
+	if (!netif_oper_up(netdev)) {
+		netdev_err(netdev, "Discarded frame: Interface not up\n");
+		kfree_skb(skb);
+		return;
+	}
Why is it sending frames when it is not up?
quoted hunk ↗ jump to hunk
+static int sparx5_inject(struct sparx5 *sparx5,
+			 u32 *ifh,
+			 struct sk_buff *skb)
+{
+	u32 val, w, count;
+	int grp = INJ_QUEUE;
+	u8 *buf;
+
+	val = spx5_rd(sparx5, QS_INJ_STATUS);
+	if (!(QS_INJ_STATUS_FIFO_RDY_GET(val) & BIT(grp))) {
+		pr_err("Injection: Queue not ready: 0x%lx\n",
+		       QS_INJ_STATUS_FIFO_RDY_GET(val));
+		return -1;
Always use -ESOMETHING.
quoted hunk ↗ jump to hunk
+	}
+
+	if (QS_INJ_STATUS_WMARK_REACHED_GET(val) & BIT(grp)) {
+		pr_err("Injection: Watermark reached: 0x%lx\n",
+		       QS_INJ_STATUS_WMARK_REACHED_GET(val));
+		return -1;
+	}
+
+	/* Indicate SOF */
+	spx5_wr(QS_INJ_CTRL_SOF_SET(1) |
+		QS_INJ_CTRL_GAP_SIZE_SET(1),
+		sparx5, QS_INJ_CTRL(grp));
+
+	// Write the IFH to the chip.
+	for (w = 0; w < IFH_LEN; w++)
+		spx5_wr(ifh[w], sparx5, QS_INJ_WR(grp));
+
+	/* Write words, round up */
+	count = ((skb->len + 3) / 4);
+	buf = skb->data;
+	for (w = 0; w < count; w++, buf += 4) {
+		val = get_unaligned((const u32 *)buf);
+		spx5_wr(val, sparx5, QS_INJ_WR(grp));
+	}
No DMA? What sort of performance do you get? Enough for the odd BPDU,
IGMP frame etc, but i guess you don't want any real bulk data to be
sent this way?
quoted hunk ↗ jump to hunk
+irqreturn_t sparx5_xtr_handler(int irq, void *_sparx5)
+{
+	struct sparx5 *sparx5 = _sparx5;
+
+	/* Check data in queue */
+	while (spx5_rd(sparx5, QS_XTR_DATA_PRESENT) & BIT(XTR_QUEUE))
+		sparx5_xtr_grp(sparx5, XTR_QUEUE, false);
+
+	return IRQ_HANDLED;
+}
Is there any sort of limit how many times this will loop? If somebody
is blasting 10Gbps at the CPU, will it ever get out of this loop?

   Andrew
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