Commit cd87fecd authored by Luiz Angelo Daros de Luca's avatar Luiz Angelo Daros de Luca Committed by David S. Miller
Browse files

net: dsa: tag_rtl8_4: add rtl8_4t trailing variant 



Realtek switches supports the same tag both before ethertype or between
payload and the CRC.

Signed-off-by: default avatarLuiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: default avatarAlvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: default avatarVladimir Oltean <olteanv@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 617c3cc3

include/net/dsa.h

+2 −0
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ struct phylink_link_state; 
#define DSA_TAG_PROTO_BRCM_LEGACY_VALUE		22

#define DSA_TAG_PROTO_SJA1110_VALUE		23

#define DSA_TAG_PROTO_RTL8_4_VALUE		24

#define DSA_TAG_PROTO_RTL8_4T_VALUE		25



enum dsa_tag_protocol {

	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -79,6 +80,7 @@ enum dsa_tag_protocol { 
	DSA_TAG_PROTO_SEVILLE		= DSA_TAG_PROTO_SEVILLE_VALUE,

	DSA_TAG_PROTO_SJA1110		= DSA_TAG_PROTO_SJA1110_VALUE,

	DSA_TAG_PROTO_RTL8_4		= DSA_TAG_PROTO_RTL8_4_VALUE,

	DSA_TAG_PROTO_RTL8_4T		= DSA_TAG_PROTO_RTL8_4T_VALUE,

};



struct dsa_switch;

net/dsa/tag_rtl8_4.c

+116 −36
Original line number Diff line number Diff line
@@ -7,13 +7,8 @@ 
 * NOTE: Currently only supports protocol "4" found in the RTL8365MB, hence

 * named tag_rtl8_4.

 *

 * This tag header has the following format:

 * This tag has the following format:

 *

 *  -------------------------------------------

 *  | MAC DA | MAC SA | 8 byte tag | Type | ...

 *  -------------------------------------------

 *     _______________/            \______________________________________

 *    /                                                                   \

 *  0                                  7|8                                 15

 *  |-----------------------------------+-----------------------------------|---

 *  |                               (16-bit)                                | ^
@@ -58,6 +53,24 @@ 
 *    TX/RX      | TX (switch->CPU): port number the packet was received on

 *               | RX (CPU->switch): forwarding port mask (if ALLOW=0)

 *               |                   allowance port mask (if ALLOW=1)

 *

 * The tag can be positioned before Ethertype, using tag "rtl8_4":

 *

 *  +--------+--------+------------+------+-----

 *  | MAC DA | MAC SA | 8 byte tag | Type | ...

 *  +--------+--------+------------+------+-----

 *

 * The tag can also appear between the end of the payload and before the CRC,

 * using tag "rtl8_4t":

 *

 * +--------+--------+------+-----+---------+------------+-----+

 * | MAC DA | MAC SA | TYPE | ... | payload | 8-byte tag | CRC |

 * +--------+--------+------+-----+---------+------------+-----+

 *

 * The added bytes after the payload will break most checksums, either in

 * software or hardware. To avoid this issue, if the checksum is still pending,

 * this tagger checksums the packet in software before adding the tag.

 *

 */



#include <linux/bitfield.h>
@@ -84,87 +97,133 @@ 
#define RTL8_4_TX			GENMASK(3, 0)

#define RTL8_4_RX			GENMASK(10, 0)



static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb,

				       struct net_device *dev)

static void rtl8_4_write_tag(struct sk_buff *skb, struct net_device *dev,

			     void *tag)

{

	struct dsa_port *dp = dsa_slave_to_port(dev);

	__be16 *tag;



	skb_push(skb, RTL8_4_TAG_LEN);



	dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN);

	tag = dsa_etype_header_pos_tx(skb);

	__be16 tag16[RTL8_4_TAG_LEN / 2];



	/* Set Realtek EtherType */

	tag[0] = htons(ETH_P_REALTEK);

	tag16[0] = htons(ETH_P_REALTEK);



	/* Set Protocol; zero REASON */

	tag[1] = htons(FIELD_PREP(RTL8_4_PROTOCOL, RTL8_4_PROTOCOL_RTL8365MB));

	tag16[1] = htons(FIELD_PREP(RTL8_4_PROTOCOL, RTL8_4_PROTOCOL_RTL8365MB));



	/* Zero FID_EN, FID, PRI_EN, PRI, KEEP; set LEARN_DIS */

	tag[2] = htons(FIELD_PREP(RTL8_4_LEARN_DIS, 1));

	tag16[2] = htons(FIELD_PREP(RTL8_4_LEARN_DIS, 1));



	/* Zero ALLOW; set RX (CPU->switch) forwarding port mask */

	tag[3] = htons(FIELD_PREP(RTL8_4_RX, BIT(dp->index)));

	tag16[3] = htons(FIELD_PREP(RTL8_4_RX, BIT(dp->index)));



	memcpy(tag, tag16, RTL8_4_TAG_LEN);

}



static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb,

				       struct net_device *dev)

{

	skb_push(skb, RTL8_4_TAG_LEN);



	dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN);



	rtl8_4_write_tag(skb, dev, dsa_etype_header_pos_tx(skb));



	return skb;

}



static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb,

static struct sk_buff *rtl8_4t_tag_xmit(struct sk_buff *skb,

					struct net_device *dev)

{

	__be16 *tag;

	/* Calculate the checksum here if not done yet as trailing tags will

	 * break either software or hardware based checksum

	 */

	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))

		return NULL;



	rtl8_4_write_tag(skb, dev, skb_put(skb, RTL8_4_TAG_LEN));



	return skb;

}



static int rtl8_4_read_tag(struct sk_buff *skb, struct net_device *dev,

			   void *tag)

{

	__be16 tag16[RTL8_4_TAG_LEN / 2];

	u16 etype;

	u8 reason;

	u8 proto;

	u8 port;



	if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN)))

		return NULL;



	tag = dsa_etype_header_pos_rx(skb);

	memcpy(tag16, tag, RTL8_4_TAG_LEN);



	/* Parse Realtek EtherType */

	etype = ntohs(tag[0]);

	etype = ntohs(tag16[0]);

	if (unlikely(etype != ETH_P_REALTEK)) {

		dev_warn_ratelimited(&dev->dev,

				     "non-realtek ethertype 0x%04x\n", etype);

		return NULL;

		return -EPROTO;

	}



	/* Parse Protocol */

	proto = FIELD_GET(RTL8_4_PROTOCOL, ntohs(tag[1]));

	proto = FIELD_GET(RTL8_4_PROTOCOL, ntohs(tag16[1]));

	if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) {

		dev_warn_ratelimited(&dev->dev,

				     "unknown realtek protocol 0x%02x\n",

				     proto);

		return NULL;

		return -EPROTO;

	}



	/* Parse REASON */

	reason = FIELD_GET(RTL8_4_REASON, ntohs(tag[1]));

	reason = FIELD_GET(RTL8_4_REASON, ntohs(tag16[1]));



	/* Parse TX (switch->CPU) */

	port = FIELD_GET(RTL8_4_TX, ntohs(tag[3]));

	port = FIELD_GET(RTL8_4_TX, ntohs(tag16[3]));

	skb->dev = dsa_master_find_slave(dev, 0, port);

	if (!skb->dev) {

		dev_warn_ratelimited(&dev->dev,

				     "could not find slave for port %d\n",

				     port);

		return NULL;

		return -ENOENT;

	}



	if (reason != RTL8_4_REASON_TRAP)

		dsa_default_offload_fwd_mark(skb);



	return 0;

}



static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb,

				      struct net_device *dev)

{

	if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN)))

		return NULL;



	if (unlikely(rtl8_4_read_tag(skb, dev, dsa_etype_header_pos_rx(skb))))

		return NULL;



	/* Remove tag and recalculate checksum */

	skb_pull_rcsum(skb, RTL8_4_TAG_LEN);



	dsa_strip_etype_header(skb, RTL8_4_TAG_LEN);



	if (reason != RTL8_4_REASON_TRAP)

		dsa_default_offload_fwd_mark(skb);

	return skb;

}



static struct sk_buff *rtl8_4t_tag_rcv(struct sk_buff *skb,

				       struct net_device *dev)

{

	if (skb_linearize(skb))

		return NULL;



	if (unlikely(rtl8_4_read_tag(skb, dev, skb_tail_pointer(skb) - RTL8_4_TAG_LEN)))

		return NULL;



	if (pskb_trim_rcsum(skb, skb->len - RTL8_4_TAG_LEN))

		return NULL;



	return skb;

}



/* Ethertype version */

static const struct dsa_device_ops rtl8_4_netdev_ops = {

	.name = "rtl8_4",

	.proto = DSA_TAG_PROTO_RTL8_4,
@@ -172,7 +231,28 @@ static const struct dsa_device_ops rtl8_4_netdev_ops = { 
	.rcv = rtl8_4_tag_rcv,

	.needed_headroom = RTL8_4_TAG_LEN,

};

module_dsa_tag_driver(rtl8_4_netdev_ops);



MODULE_LICENSE("GPL");

DSA_TAG_DRIVER(rtl8_4_netdev_ops);



MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4);



/* Tail version */

static const struct dsa_device_ops rtl8_4t_netdev_ops = {

	.name = "rtl8_4t",

	.proto = DSA_TAG_PROTO_RTL8_4T,

	.xmit = rtl8_4t_tag_xmit,

	.rcv = rtl8_4t_tag_rcv,

	.needed_tailroom = RTL8_4_TAG_LEN,

};



DSA_TAG_DRIVER(rtl8_4t_netdev_ops);



MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4L);



static struct dsa_tag_driver *dsa_tag_drivers[] = {

	&DSA_TAG_DRIVER_NAME(rtl8_4_netdev_ops),

	&DSA_TAG_DRIVER_NAME(rtl8_4t_netdev_ops),

};

module_dsa_tag_drivers(dsa_tag_drivers);



MODULE_LICENSE("GPL");