[PATCH V3 2/3] net-next: dsa: add Qualcomm tag RX/TX handler
From: John Crispin
Date: Thu Sep 15 2016 - 10:29:29 EST
Add support for the 2-bytes Qualcomm tag that gigabit switches such as
the QCA8337/N might insert when receiving packets, or that we need
to insert while targeting specific switch ports. The tag is inserted
directly behind the ethernet header.
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: John Crispin <john@xxxxxxxxxxx>
---
Changes in V2
* fix some comments
* remove dead code
* rename variable from phy->reg
include/net/dsa.h | 1 +
net/dsa/Kconfig | 3 ++
net/dsa/Makefile | 1 +
net/dsa/dsa.c | 3 ++
net/dsa/dsa_priv.h | 2 +
net/dsa/tag_qca.c | 138 ++++++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 148 insertions(+)
create mode 100644 net/dsa/tag_qca.c
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 24ee961..7fdd63e 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -26,6 +26,7 @@ enum dsa_tag_protocol {
DSA_TAG_PROTO_TRAILER,
DSA_TAG_PROTO_EDSA,
DSA_TAG_PROTO_BRCM,
+ DSA_TAG_PROTO_QCA,
DSA_TAG_LAST, /* MUST BE LAST */
};
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index ff7736f..96e47c5 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -38,4 +38,7 @@ config NET_DSA_TAG_EDSA
config NET_DSA_TAG_TRAILER
bool
+config NET_DSA_TAG_QCA
+ bool
+
endif
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index 8af4ded..a3380ed 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -7,3 +7,4 @@ dsa_core-$(CONFIG_NET_DSA_TAG_BRCM) += tag_brcm.o
dsa_core-$(CONFIG_NET_DSA_TAG_DSA) += tag_dsa.o
dsa_core-$(CONFIG_NET_DSA_TAG_EDSA) += tag_edsa.o
dsa_core-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o
+dsa_core-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index d8d267e..66e31ac 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -54,6 +54,9 @@ const struct dsa_device_ops *dsa_device_ops[DSA_TAG_LAST] = {
#ifdef CONFIG_NET_DSA_TAG_BRCM
[DSA_TAG_PROTO_BRCM] = &brcm_netdev_ops,
#endif
+#ifdef CONFIG_NET_DSA_TAG_QCA
+ [DSA_TAG_PROTO_QCA] = &qca_netdev_ops,
+#endif
[DSA_TAG_PROTO_NONE] = &none_ops,
};
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 00077a9..6cfd738 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -81,5 +81,7 @@ extern const struct dsa_device_ops trailer_netdev_ops;
/* tag_brcm.c */
extern const struct dsa_device_ops brcm_netdev_ops;
+/* tag_qca.c */
+extern const struct dsa_device_ops qca_netdev_ops;
#endif
diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c
new file mode 100644
index 0000000..0c90cac
--- /dev/null
+++ b/net/dsa/tag_qca.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/etherdevice.h>
+#include "dsa_priv.h"
+
+#define QCA_HDR_LEN 2
+#define QCA_HDR_VERSION 0x2
+
+#define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14)
+#define QCA_HDR_RECV_VERSION_S 14
+#define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11)
+#define QCA_HDR_RECV_PRIORITY_S 11
+#define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6)
+#define QCA_HDR_RECV_TYPE_S 6
+#define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3)
+#define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
+
+#define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14)
+#define QCA_HDR_XMIT_VERSION_S 14
+#define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11)
+#define QCA_HDR_XMIT_PRIORITY_S 11
+#define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8)
+#define QCA_HDR_XMIT_CONTROL_S 8
+#define QCA_HDR_XMIT_FROM_CPU BIT(7)
+#define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0)
+
+static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct dsa_slave_priv *p = netdev_priv(dev);
+ u16 *phdr, hdr;
+
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
+
+ if (skb_cow_head(skb, 0) < 0)
+ goto out_free;
+
+ skb_push(skb, QCA_HDR_LEN);
+
+ memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
+ phdr = (u16 *)(skb->data + 2 * ETH_ALEN);
+
+ /* Set the version field, and set destination port information */
+ hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S |
+ QCA_HDR_XMIT_FROM_CPU |
+ BIT(p->port);
+
+ *phdr = htons(hdr);
+
+ return skb;
+
+out_free:
+ kfree_skb(skb);
+ return NULL;
+}
+
+static int qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct dsa_switch_tree *dst = dev->dsa_ptr;
+ struct dsa_switch *ds;
+ u8 ver;
+ int port;
+ __be16 *phdr, hdr;
+
+ if (unlikely(!dst))
+ goto out_drop;
+
+ skb = skb_unshare(skb, GFP_ATOMIC);
+ if (!skb)
+ goto out;
+
+ if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
+ goto out_drop;
+
+ /* The QCA header is added by the switch between src addr and Ethertype
+ * At this point, skb->data points to ethertype so header should be
+ * right before
+ */
+ phdr = (__be16 *)(skb->data - 2);
+ hdr = ntohs(*phdr);
+
+ /* Make sure the version is correct */
+ ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
+ if (unlikely(ver != QCA_HDR_VERSION))
+ goto out_drop;
+
+ /* Remove QCA tag and recalculate checksum */
+ skb_pull_rcsum(skb, QCA_HDR_LEN);
+ memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
+ ETH_HLEN - QCA_HDR_LEN);
+
+ /* This protocol doesn't support cascading multiple switches so it's
+ * safe to assume the switch is first in the tree
+ */
+ ds = dst->ds[0];
+ if (!ds)
+ goto out_drop;
+
+ /* Get source port information */
+ port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
+ if (!ds->ports[port].netdev)
+ goto out_drop;
+
+ /* Update skb & forward the frame accordingly */
+ skb_push(skb, ETH_HLEN);
+ skb->pkt_type = PACKET_HOST;
+ skb->dev = ds->ports[port].netdev;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+
+ skb->dev->stats.rx_packets++;
+ skb->dev->stats.rx_bytes += skb->len;
+
+ netif_receive_skb(skb);
+
+ return 0;
+
+out_drop:
+ kfree_skb(skb);
+out:
+ return 0;
+}
+
+const struct dsa_device_ops qca_netdev_ops = {
+ .xmit = qca_tag_xmit,
+ .rcv = qca_tag_rcv,
+};
--
1.7.10.4