net: mscc: ocelot: refactor ocelot_xtr_irq_handler into ocelot_xtr_poll

Since the felix DSA driver will need to poll the CPU port module for
extracted frames as well, let's create some common functions that read
an Extraction Frame Header, and then an skb, from a CPU extraction
group.

We abuse the struct ocelot_ops :: port_to_netdev function a little bit,
in order to retrieve the DSA port net_device or the ocelot switchdev
net_device based on the source port information from the Extraction
Frame Header, but it's all in the benefit of code simplification -
netdev_alloc_skb needs it. Originally, the port_to_netdev method was
intended for parsing act->dev from tc flower offload code.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 151 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 699b0c1c1780..981811ffcdae 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -629,6 +629,157 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
 }
 EXPORT_SYMBOL(ocelot_get_txtstamp);
 
+static int ocelot_rx_frame_word(struct ocelot *ocelot, u8 grp, bool ifh,
+				u32 *rval)
+{
+	u32 bytes_valid, val;
+
+	val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+	if (val == XTR_NOT_READY) {
+		if (ifh)
+			return -EIO;
+
+		do {
+			val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		} while (val == XTR_NOT_READY);
+	}
+
+	switch (val) {
+	case XTR_ABORT:
+		return -EIO;
+	case XTR_EOF_0:
+	case XTR_EOF_1:
+	case XTR_EOF_2:
+	case XTR_EOF_3:
+	case XTR_PRUNED:
+		bytes_valid = XTR_VALID_BYTES(val);
+		val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		if (val == XTR_ESCAPE)
+			*rval = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		else
+			*rval = val;
+
+		return bytes_valid;
+	case XTR_ESCAPE:
+		*rval = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+
+		return 4;
+	default:
+		*rval = val;
+
+		return 4;
+	}
+}
+
+static int ocelot_xtr_poll_xfh(struct ocelot *ocelot, int grp, u32 *xfh)
+{
+	int i, err = 0;
+
+	for (i = 0; i < OCELOT_TAG_LEN / 4; i++) {
+		err = ocelot_rx_frame_word(ocelot, grp, true, &xfh[i]);
+		if (err != 4)
+			return (err < 0) ? err : -EIO;
+	}
+
+	return 0;
+}
+
+int ocelot_xtr_poll_frame(struct ocelot *ocelot, int grp, struct sk_buff **nskb)
+{
+	struct skb_shared_hwtstamps *shhwtstamps;
+	u64 tod_in_ns, full_ts_in_ns;
+	u64 timestamp, src_port, len;
+	u32 xfh[OCELOT_TAG_LEN / 4];
+	struct net_device *dev;
+	struct timespec64 ts;
+	struct sk_buff *skb;
+	int sz, buf_len;
+	u32 val, *buf;
+	int err;
+
+	err = ocelot_xtr_poll_xfh(ocelot, grp, xfh);
+	if (err)
+		return err;
+
+	ocelot_xfh_get_src_port(xfh, &src_port);
+	ocelot_xfh_get_len(xfh, &len);
+	ocelot_xfh_get_rew_val(xfh, &timestamp);
+
+	if (WARN_ON(src_port >= ocelot->num_phys_ports))
+		return -EINVAL;
+
+	dev = ocelot->ops->port_to_netdev(ocelot, src_port);
+	if (!dev)
+		return -EINVAL;
+
+	skb = netdev_alloc_skb(dev, len);
+	if (unlikely(!skb)) {
+		netdev_err(dev, "Unable to allocate sk_buff\n");
+		return -ENOMEM;
+	}
+
+	buf_len = len - ETH_FCS_LEN;
+	buf = (u32 *)skb_put(skb, buf_len);
+
+	len = 0;
+	do {
+		sz = ocelot_rx_frame_word(ocelot, grp, false, &val);
+		if (sz < 0) {
+			err = sz;
+			goto out_free_skb;
+		}
+		*buf++ = val;
+		len += sz;
+	} while (len < buf_len);
+
+	/* Read the FCS */
+	sz = ocelot_rx_frame_word(ocelot, grp, false, &val);
+	if (sz < 0) {
+		err = sz;
+		goto out_free_skb;
+	}
+
+	/* Update the statistics if part of the FCS was read before */
+	len -= ETH_FCS_LEN - sz;
+
+	if (unlikely(dev->features & NETIF_F_RXFCS)) {
+		buf = (u32 *)skb_put(skb, ETH_FCS_LEN);
+		*buf = val;
+	}
+
+	if (ocelot->ptp) {
+		ocelot_ptp_gettime64(&ocelot->ptp_info, &ts);
+
+		tod_in_ns = ktime_set(ts.tv_sec, ts.tv_nsec);
+		if ((tod_in_ns & 0xffffffff) < timestamp)
+			full_ts_in_ns = (((tod_in_ns >> 32) - 1) << 32) |
+					timestamp;
+		else
+			full_ts_in_ns = (tod_in_ns & GENMASK_ULL(63, 32)) |
+					timestamp;
+
+		shhwtstamps = skb_hwtstamps(skb);
+		memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
+		shhwtstamps->hwtstamp = full_ts_in_ns;
+	}
+
+	/* Everything we see on an interface that is in the HW bridge
+	 * has already been forwarded.
+	 */
+	if (ocelot->bridge_mask & BIT(src_port))
+		skb->offload_fwd_mark = 1;
+
+	skb->protocol = eth_type_trans(skb, dev);
+	*nskb = skb;
+
+	return 0;
+
+out_free_skb:
+	kfree_skb(skb);
+	return err;
+}
+EXPORT_SYMBOL(ocelot_xtr_poll_frame);
+
 bool ocelot_can_inject(struct ocelot *ocelot, int grp)
 {
 	u32 val = ocelot_read(ocelot, QS_INJ_STATUS);