[RFC PATCH net-next 01/11] net: dsa: microchip: lan937x: add cascade tailtag
From: Rakesh Sankaranarayanan
Date: Thu Feb 02 2023 - 07:58:51 EST
cascade tailtag contains 3 bytes of information, it includes
additional bytes for accomodating port number in second switch.
Destination port bitmap on first switch is at bit position 7:0 and
of second switch is at bit position 15:8, add new tailtag xmit and
rcv functions for cascade with proper formatting. Add new tag protocol
for cascading and link with new xmit and rcv functions.
Signed-off-by: Rakesh Sankaranarayanan <rakesh.sankaranarayanan@xxxxxxxxxxxxx>
---
include/net/dsa.h | 2 ++
net/dsa/tag_ksz.c | 80 ++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 77 insertions(+), 5 deletions(-)
diff --git a/include/net/dsa.h b/include/net/dsa.h
index a15f17a38eca..55651ad29193 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -56,6 +56,7 @@ struct phylink_link_state;
#define DSA_TAG_PROTO_RTL8_4T_VALUE 25
#define DSA_TAG_PROTO_RZN1_A5PSW_VALUE 26
#define DSA_TAG_PROTO_LAN937X_VALUE 27
+#define DSA_TAG_PROTO_LAN937X_CASCADE_VALUE 28
enum dsa_tag_protocol {
DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE,
@@ -86,6 +87,7 @@ enum dsa_tag_protocol {
DSA_TAG_PROTO_RTL8_4T = DSA_TAG_PROTO_RTL8_4T_VALUE,
DSA_TAG_PROTO_RZN1_A5PSW = DSA_TAG_PROTO_RZN1_A5PSW_VALUE,
DSA_TAG_PROTO_LAN937X = DSA_TAG_PROTO_LAN937X_VALUE,
+ DSA_TAG_PROTO_LAN937X_CASCADE = DSA_TAG_PROTO_LAN937X_CASCADE_VALUE,
};
struct dsa_switch;
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 0eb1c7784c3d..7ab2c7eaa4ca 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -16,6 +16,7 @@
#define KSZ9477_NAME "ksz9477"
#define KSZ9893_NAME "ksz9893"
#define LAN937X_NAME "lan937x"
+#define LAN937X_CASCADE_NAME "lan937x_cascade"
/* Typically only one byte is used for tail tag. */
#define KSZ_PTP_TAG_LEN 4
@@ -24,6 +25,9 @@
#define KSZ_HWTS_EN 0
+#define SWITCH_0 0
+#define SWITCH_1 1
+
struct ksz_tagger_private {
struct ksz_tagger_data data; /* Must be first */
unsigned long state;
@@ -84,10 +88,10 @@ static int ksz_connect(struct dsa_switch *ds)
}
static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
- struct net_device *dev,
- unsigned int port, unsigned int len)
+ struct net_device *dev, unsigned int port,
+ unsigned int len, u8 device)
{
- skb->dev = dsa_master_find_slave(dev, 0, port);
+ skb->dev = dsa_master_find_slave(dev, device, port);
if (!skb->dev)
return NULL;
@@ -141,7 +145,7 @@ static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
{
u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
- return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
+ return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN, SWITCH_0);
}
static const struct dsa_device_ops ksz8795_netdev_ops = {
@@ -177,6 +181,7 @@ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
#define KSZ9477_INGRESS_TAG_LEN 2
#define KSZ9477_PTP_TAG_LEN 4
#define KSZ9477_PTP_TAG_INDICATION 0x80
+#define LAN937X_CASCADE_CHIP 0x40
#define KSZ9477_TAIL_TAG_PRIO GENMASK(8, 7)
#define KSZ9477_TAIL_TAG_OVERRIDE BIT(9)
@@ -304,6 +309,7 @@ static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
unsigned int port = tag[0] & 7;
unsigned int len = KSZ_EGRESS_TAG_LEN;
+ u8 device = SWITCH_0;
/* Extra 4-bytes PTP timestamp */
if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
@@ -311,7 +317,10 @@ static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
len += KSZ_PTP_TAG_LEN;
}
- return ksz_common_rcv(skb, dev, port, len);
+ if (tag[0] & LAN937X_CASCADE_CHIP)
+ device = SWITCH_1;
+
+ return ksz_common_rcv(skb, dev, port, len, device);
}
static const struct dsa_device_ops ksz9477_netdev_ops = {
@@ -390,6 +399,7 @@ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
* (eg, 0x00=port1, 0x02=port3, 0x07=port8)
*/
#define LAN937X_EGRESS_TAG_LEN 2
+#define LAN937X_CASCADE_TAG_LEN 3
#define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE BIT(11)
#define LAN937X_TAIL_TAG_LOOKUP BIT(12)
@@ -442,11 +452,71 @@ static const struct dsa_device_ops lan937x_netdev_ops = {
DSA_TAG_DRIVER(lan937x_netdev_ops);
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);
+/* For xmit, 3/7 bytes are added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
+ * tag2(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * ts : time stamp (Present only if PTP is enabled in the Hardware)
+ * tag0 : represents tag override, lookup and valid
+ * tag1 : each bit represents destination port map through switch 2
+ * (eg, 0x01=port1, 0x02=port2, 0x80=port8)
+ * tag2 : each bit represents destination port map through switch 1
+ * (eg, 0x01=port1, 0x02=port2, 0x80=port8)
+ *
+ * For rcv, 1/5 bytes is added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * ts : time stamp (Present only if bit 7 of tag0 is set)
+ * tag0 : zero-based value represents port
+ * (eg, 0x00=port1, 0x02=port3, 0x07=port8)
+ */
+static struct sk_buff *lan937x_cascade_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct dsa_port *dp = dsa_slave_to_port(dev);
+ const struct ethhdr *hdr = eth_hdr(skb);
+ __be32 *tag;
+ u32 val;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
+ return NULL;
+
+ tag = skb_put(skb, LAN937X_CASCADE_TAG_LEN);
+
+ val |= BIT((dp->index + (8 * dp->ds->index)));
+
+ if (is_link_local_ether_addr(hdr->h_dest))
+ val |= (LAN937X_TAIL_TAG_BLOCKING_OVERRIDE << 8);
+
+ val |= (LAN937X_TAIL_TAG_VALID << 8);
+
+ put_unaligned_be24(val, tag);
+
+ return skb;
+}
+
+static const struct dsa_device_ops lan937x_cascade_netdev_ops = {
+ .name = LAN937X_CASCADE_NAME,
+ .proto = DSA_TAG_PROTO_LAN937X_CASCADE,
+ .xmit = lan937x_cascade_xmit,
+ .rcv = ksz9477_rcv,
+ .connect = ksz_connect,
+ .disconnect = ksz_disconnect,
+ .needed_tailroom = LAN937X_CASCADE_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(lan937x_cascade_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937x_CASCADE,
+ LAN937X_CASCADE_NAME);
+
static struct dsa_tag_driver *dsa_tag_driver_array[] = {
&DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
&DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
&DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
&DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
+ &DSA_TAG_DRIVER_NAME(lan937x_cascade_netdev_ops),
};
module_dsa_tag_drivers(dsa_tag_driver_array);
--
2.34.1