[linux.git] / net / dsa / tag_qca.c

/*
 * 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)
		return NULL;

	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->dp->index);

	*phdr = htons(hdr);

	return skb;
}

static struct sk_buff *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_port *cpu_dp = dsa_get_cpu_port(dst);
	struct dsa_switch *ds;
	u8 ver;
	int port;
	__be16 *phdr, hdr;

	if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
		return NULL;

	/* 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))
		return NULL;

	/* 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 = cpu_dp->ds;
	if (!ds)
		return NULL;

	/* Get source port information */
	port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
	if (!ds->ports[port].netdev)
		return NULL;

	/* Update skb & forward the frame accordingly */
	skb->dev = ds->ports[port].netdev;

	return skb;
}

const struct dsa_device_ops qca_netdev_ops = {
	.xmit	= qca_tag_xmit,
	.rcv	= qca_tag_rcv,
};
Commit	Line	Data
cafdc45c JC	1	/*
	2	* Copyright (c) 2015, The Linux Foundation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 and
	6	* only version 2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
	12	*/
	13
	14	#include <linux/etherdevice.h>
ea5dd34b	15
cafdc45c JC	16	#include "dsa_priv.h"
	17
	18	#define QCA_HDR_LEN 2
	19	#define QCA_HDR_VERSION 0x2
	20
	21	#define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14)
	22	#define QCA_HDR_RECV_VERSION_S 14
	23	#define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11)
	24	#define QCA_HDR_RECV_PRIORITY_S 11
	25	#define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6)
	26	#define QCA_HDR_RECV_TYPE_S 6
	27	#define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3)
	28	#define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
	29
	30	#define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14)
	31	#define QCA_HDR_XMIT_VERSION_S 14
	32	#define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11)
	33	#define QCA_HDR_XMIT_PRIORITY_S 11
	34	#define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8)
	35	#define QCA_HDR_XMIT_CONTROL_S 8
	36	#define QCA_HDR_XMIT_FROM_CPU BIT(7)
	37	#define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0)
	38
	39	static struct sk_buff qca_tag_xmit(struct sk_buff skb, struct net_device *dev)
	40	{
	41	struct dsa_slave_priv *p = netdev_priv(dev);
	42	u16 *phdr, hdr;
	43
	44	dev->stats.tx_packets++;
	45	dev->stats.tx_bytes += skb->len;
	46
	47	if (skb_cow_head(skb, 0) < 0)
fe47d563	48	return NULL;
cafdc45c JC	49
	50	skb_push(skb, QCA_HDR_LEN);
	51
	52	memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
	53	phdr = (u16 )(skb->data + 2 ETH_ALEN);
	54
	55	/* Set the version field, and set destination port information */
	56	hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S \|
	57	QCA_HDR_XMIT_FROM_CPU \|
afdcf151	58	BIT(p->dp->index);
cafdc45c JC	59
	60	*phdr = htons(hdr);
	61
	62	return skb;
cafdc45c JC	63	}
cafdc45c JC	64
a86d8bec FF	65	static struct sk_buff qca_tag_rcv(struct sk_buff skb, struct net_device *dev,
	66	struct packet_type *pt,
	67	struct net_device *orig_dev)
cafdc45c JC	68	{
cafdc45c JC	69	struct dsa_switch_tree *dst = dev->dsa_ptr;
3cc9f257	70	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
cafdc45c JC	71	struct dsa_switch *ds;
	72	u8 ver;
	73	int port;
	74	__be16 *phdr, hdr;
	75
cafdc45c	76	if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
54709795	77	return NULL;
cafdc45c JC	78
	79	/* The QCA header is added by the switch between src addr and Ethertype
	80	* At this point, skb->data points to ethertype so header should be
	81	* right before
	82	*/
	83	phdr = (__be16 *)(skb->data - 2);
	84	hdr = ntohs(*phdr);
	85
	86	/* Make sure the version is correct */
	87	ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
	88	if (unlikely(ver != QCA_HDR_VERSION))
54709795	89	return NULL;
cafdc45c JC	90
	91	/* Remove QCA tag and recalculate checksum */
	92	skb_pull_rcsum(skb, QCA_HDR_LEN);
	93	memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
	94	ETH_HLEN - QCA_HDR_LEN);
	95
	96	/* This protocol doesn't support cascading multiple switches so it's
	97	* safe to assume the switch is first in the tree
	98	*/
3cc9f257	99	ds = cpu_dp->ds;
cafdc45c	100	if (!ds)
54709795	101	return NULL;
cafdc45c JC	102
	103	/* Get source port information */
	104	port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
	105	if (!ds->ports[port].netdev)
54709795	106	return NULL;
cafdc45c JC	107
cafdc45c JC	108	/* Update skb & forward the frame accordingly */
cafdc45c	109	skb->dev = ds->ports[port].netdev;
cafdc45c	110
a86d8bec	111	return skb;
cafdc45c JC	112	}
	113
	114	const struct dsa_device_ops qca_netdev_ops = {
	115	.xmit = qca_tag_xmit,
	116	.rcv = qca_tag_rcv,
	117	};