/*
 * net/dsa/tag_dsa.c - (Non-ethertype) DSA tagging
 * Copyright (c) 2008-2009 Marvell Semiconductor
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/slab.h>
#include "dsa_priv.h"

#define DSA_HLEN	4

static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct dsa_slave_priv *p = netdev_priv(dev);
	u8 *dsa_header;

	/*
	 * Convert the outermost 802.1q tag to a DSA tag for tagged
	 * packets, or insert a DSA tag between the addresses and
	 * the ethertype field for untagged packets.
	 */
	if (skb->protocol == htons(ETH_P_8021Q)) {
		if (skb_cow_head(skb, 0) < 0)
			goto out_free;

		/*
		 * Construct tagged FROM_CPU DSA tag from 802.1q tag.
		 */
		dsa_header = skb->data + 2 * ETH_ALEN;
		dsa_header[0] = 0x60 | p->dp->ds->index;
		dsa_header[1] = p->dp->index << 3;

		/*
		 * Move CFI field from byte 2 to byte 1.
		 */
		if (dsa_header[2] & 0x10) {
			dsa_header[1] |= 0x01;
			dsa_header[2] &= ~0x10;
		}
	} else {
		if (skb_cow_head(skb, DSA_HLEN) < 0)
			goto out_free;
		skb_push(skb, DSA_HLEN);

		memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN);

		/*
		 * Construct untagged FROM_CPU DSA tag.
		 */
		dsa_header = skb->data + 2 * ETH_ALEN;
		dsa_header[0] = 0x40 | p->dp->ds->index;
		dsa_header[1] = p->dp->index << 3;
		dsa_header[2] = 0x00;
		dsa_header[3] = 0x00;
	}

	return skb;

out_free:
	kfree_skb(skb);
	return NULL;
}

static int dsa_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 *dsa_header;
	int source_device;
	int source_port;

	if (unlikely(dst == NULL))
		goto out_drop;

	skb = skb_unshare(skb, GFP_ATOMIC);
	if (skb == NULL)
		goto out;

	if (unlikely(!pskb_may_pull(skb, DSA_HLEN)))
		goto out_drop;

	/*
	 * The ethertype field is part of the DSA header.
	 */
	dsa_header = skb->data - 2;

	/*
	 * Check that frame type is either TO_CPU or FORWARD.
	 */
	if ((dsa_header[0] & 0xc0) != 0x00 && (dsa_header[0] & 0xc0) != 0xc0)
		goto out_drop;

	/*
	 * Determine source device and port.
	 */
	source_device = dsa_header[0] & 0x1f;
	source_port = (dsa_header[1] >> 3) & 0x1f;

	/*
	 * Check that the source device exists and that the source
	 * port is a registered DSA port.
	 */
	if (source_device >= DSA_MAX_SWITCHES)
		goto out_drop;

	ds = dst->ds[source_device];
	if (!ds)
		goto out_drop;

	if (source_port >= ds->num_ports || !ds->ports[source_port].netdev)
		goto out_drop;

	/*
	 * Convert the DSA header to an 802.1q header if the 'tagged'
	 * bit in the DSA header is set.  If the 'tagged' bit is clear,
	 * delete the DSA header entirely.
	 */
	if (dsa_header[0] & 0x20) {
		u8 new_header[4];

		/*
		 * Insert 802.1q ethertype and copy the VLAN-related
		 * fields, but clear the bit that will hold CFI (since
		 * DSA uses that bit location for another purpose).
		 */
		new_header[0] = (ETH_P_8021Q >> 8) & 0xff;
		new_header[1] = ETH_P_8021Q & 0xff;
		new_header[2] = dsa_header[2] & ~0x10;
		new_header[3] = dsa_header[3];

		/*
		 * Move CFI bit from its place in the DSA header to
		 * its 802.1q-designated place.
		 */
		if (dsa_header[1] & 0x01)
			new_header[2] |= 0x10;

		/*
		 * Update packet checksum if skb is CHECKSUM_COMPLETE.
		 */
		if (skb->ip_summed == CHECKSUM_COMPLETE) {
			__wsum c = skb->csum;
			c = csum_add(c, csum_partial(new_header + 2, 2, 0));
			c = csum_sub(c, csum_partial(dsa_header + 2, 2, 0));
			skb->csum = c;
		}

		memcpy(dsa_header, new_header, DSA_HLEN);
	} else {
		/*
		 * Remove DSA tag and update checksum.
		 */
		skb_pull_rcsum(skb, DSA_HLEN);
		memmove(skb->data - ETH_HLEN,
			skb->data - ETH_HLEN - DSA_HLEN,
			2 * ETH_ALEN);
	}

	skb->dev = ds->ports[source_port].netdev;
	skb_push(skb, ETH_HLEN);
	skb->pkt_type = PACKET_HOST;
	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 dsa_netdev_ops = {
	.xmit	= dsa_xmit,
	.rcv	= dsa_rcv,
};
/patch/?id=95cc44a04f4c364affbc194820ad4ca5ab88f30c'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=95cc44a04f4c364affbc194820ad4ca5ab88f30c'>9759b4fb11fab5e0069e1cb6cf01ce3b6781390c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?id=cf957ccc76eeffee9f06d2f8f7c9260015076e92'>cf957ccc76eeffee9f06d2f8f7c9260015076e92</a> (<a href='/cgit.cgi/linux/net-next.git/diff/?id=95cc44a04f4c364affbc194820ad4ca5ab88f30c&amp;id2=cf957ccc76eeffee9f06d2f8f7c9260015076e92'>diff</a>)</td></tr></table>
<div class='commit-subject'>fbdev: vfb: add option for video mode</div><div class='commit-msg'>Make vfb a bit more flexible in sense what it can represent and allow
the end user to specify video mode parameters via newly introduced module
option "mode". Since it is test module it is still up to the end user
to make sure there is enough memory to satisfy video mode settings.

Signed-off-by: Vladimir Murzin &lt;vladimir.murzin@arm.com&gt;
[tomi.valkeinen@ti.com: constified vfb_default]
Signed-off-by: Tomi Valkeinen &lt;tomi.valkeinen@ti.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=95cc44a04f4c364affbc194820ad4ca5ab88f30c'>Diffstat</a></div><table summary='diffstat' class='diffstat'>