net-next: dsa: add Qualcomm tag RX/TX handler

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@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 9d97c5214341b8ef0a3e33a3263565f2cf4fbc54..7556646db2d343d1008f25d4e618cc9b4e46ddd8 100644 (file)
--- 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 ff7736f7ff42d335b08cef345b3b1309e81b7985..96e47c539beed85ac031192f8943f91f8bb86855 100644 (file)
--- 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 8af4ded70f1c90efb8e708dc6868a6e5d9ecf9c3..a3380ed0e0be56d1cc3a22be1929c63ba9090288 100644 (file)
--- 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 d8d267e9a872caa9f7a21c6c8719847ff5508445..66e31acfcad8c1dbc9d34e505528aee4ce433f54 100644 (file)
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -53,6 +53,9 @@ const struct dsa_device_ops *dsa_device_ops[DSA_TAG_LAST] = {
 #endif
 #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 00077a9c97f416d8cc6a167a22bc0a2053e7d6ab..6cfd7388834e3a118e81ece3779f56023bfca488 100644 (file)
--- 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 (file)
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,
+};