net: dsa: ksz: Factor out common tag code

Factor out common code from the tag_ksz , so that the code can be used
with other KSZ family switches which use differenly sized tags.

Signed-off-by: Tristram Ha <Tristram.Ha@microchip.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Cc: Woojung Huh <woojung.huh@microchip.com>
Cc: David S. Miller <davem@davemloft.net>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index c24a333e55bdebac2839c96dc8d64829c46aa3f2..c98b53f691bd442a74fb5cfe4bdca906da38ebf6 100644 (file)
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -14,34 +14,18 @@
 #include <net/dsa.h>
 #include "dsa_priv.h"
 
-/* For Ingress (Host -> KSZ), 2 bytes are added before FCS.
- * ---------------------------------------------------------------------------
- * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
- * ---------------------------------------------------------------------------
- * tag0 : Prioritization (not used now)
- * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
- *
- * For Egress (KSZ -> Host), 1 byte is added before FCS.
- * ---------------------------------------------------------------------------
- * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
- * ---------------------------------------------------------------------------
- * tag0 : zero-based value represents port
- *       (eg, 0x00=port1, 0x02=port3, 0x06=port7)
- */
+/* Typically only one byte is used for tail tag. */
+#define KSZ_EGRESS_TAG_LEN             1
 
-#define        KSZ_INGRESS_TAG_LEN     2
-#define        KSZ_EGRESS_TAG_LEN      1
-
-static struct sk_buff *ksz_xmit(struct sk_buff *skb, struct net_device *dev)
+static struct sk_buff *ksz_common_xmit(struct sk_buff *skb,
+                                      struct net_device *dev, int len)
 {
-       struct dsa_port *dp = dsa_slave_to_port(dev);
        struct sk_buff *nskb;
        int padlen;
-       u8 *tag;
 
        padlen = (skb->len >= ETH_ZLEN) ? 0 : ETH_ZLEN - skb->len;
 
-       if (skb_tailroom(skb) >= padlen + KSZ_INGRESS_TAG_LEN) {
+       if (skb_tailroom(skb) >= padlen + len) {
                /* Let dsa_slave_xmit() free skb */
                if (__skb_put_padto(skb, skb->len + padlen, false))
                        return NULL;
@@ -49,7 +33,7 @@ static struct sk_buff *ksz_xmit(struct sk_buff *skb, struct net_device *dev)
                nskb = skb;
        } else {
                nskb = alloc_skb(NET_IP_ALIGN + skb->len +
-                                padlen + KSZ_INGRESS_TAG_LEN, GFP_ATOMIC);
+                                padlen + len, GFP_ATOMIC);
                if (!nskb)
                        return NULL;
                skb_reserve(nskb, NET_IP_ALIGN);
@@ -70,34 +54,84 @@ static struct sk_buff *ksz_xmit(struct sk_buff *skb, struct net_device *dev)
                consume_skb(skb);
        }
 
-       tag = skb_put(nskb, KSZ_INGRESS_TAG_LEN);
-       tag[0] = 0;
-       tag[1] = 1 << dp->index; /* destination port */
-
        return nskb;
 }
 
-static struct sk_buff *ksz_rcv(struct sk_buff *skb, struct net_device *dev,
-                              struct packet_type *pt)
+static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
+                                     struct net_device *dev,
+                                     unsigned int port, unsigned int len)
 {
-       u8 *tag;
-       int source_port;
+       skb->dev = dsa_master_find_slave(dev, 0, port);
+       if (!skb->dev)
+               return NULL;
 
-       tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
+       pskb_trim_rcsum(skb, skb->len - len);
 
-       source_port = tag[0] & 7;
+       return skb;
+}
 
-       skb->dev = dsa_master_find_slave(dev, 0, source_port);
-       if (!skb->dev)
+/*
+ * For Ingress (Host -> KSZ9477), 2 bytes are added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|tag1(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * tag0 : Prioritization (not used now)
+ * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
+ *
+ * For Egress (KSZ9477 -> Host), 1 byte is added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * tag0 : zero-based value represents port
+ *       (eg, 0x00=port1, 0x02=port3, 0x06=port7)
+ */
+
+#define KSZ9477_INGRESS_TAG_LEN                2
+#define KSZ9477_PTP_TAG_LEN            4
+#define KSZ9477_PTP_TAG_INDICATION     0x80
+
+#define KSZ9477_TAIL_TAG_OVERRIDE      BIT(9)
+#define KSZ9477_TAIL_TAG_LOOKUP                BIT(10)
+
+static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
+                                   struct net_device *dev)
+{
+       struct dsa_port *dp = dsa_slave_to_port(dev);
+       struct sk_buff *nskb;
+       u16 *tag;
+       u8 *addr;
+
+       nskb = ksz_common_xmit(skb, dev, KSZ9477_INGRESS_TAG_LEN);
+       if (!nskb)
                return NULL;
 
-       pskb_trim_rcsum(skb, skb->len - KSZ_EGRESS_TAG_LEN);
+       /* Tag encoding */
+       tag = skb_put(nskb, KSZ9477_INGRESS_TAG_LEN);
+       addr = skb_mac_header(nskb);
 
-       return skb;
+       *tag = BIT(dp->index);
+       *tag = cpu_to_be16(*tag);
+
+       return nskb;
+}
+
+static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev,
+                                  struct packet_type *pt)
+{
+       /* Tag decoding */
+       u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
+       unsigned int port = tag[0] & 7;
+       unsigned int len = KSZ_EGRESS_TAG_LEN;
+
+       /* Extra 4-bytes PTP timestamp */
+       if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
+               len += KSZ9477_PTP_TAG_LEN;
+
+       return ksz_common_rcv(skb, dev, port, len);
 }
 
 const struct dsa_device_ops ksz9477_netdev_ops = {
-       .xmit   = ksz_xmit,
-       .rcv    = ksz_rcv,
-       .overhead = KSZ_INGRESS_TAG_LEN,
+       .xmit   = ksz9477_xmit,
+       .rcv    = ksz9477_rcv,
+       .overhead = KSZ9477_INGRESS_TAG_LEN,
 };